© 2008 Microchip Technology Inc. Preliminary DS39778C
PIC18F87J11 Family
Data Sheet
64/80-Pin High-Performance,
1-Mbit Flash Microcontrollers
with nanoWatt Technology
DS39778C-page ii Preliminary © 2008 Microchip Technology Inc.
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© 2008, Microchip Technology Incorporated, Printed in the
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Note the following details of the code protection feature on Microchip devices:
Microchip products meet the specification contained in their particular Microchip Data Sheet.
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
Microchip is willing to work with the customer who is concerned about the integrity of their code.
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
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Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
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and manufacture of development systems is ISO 9001:2000 certified.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 1
PIC18F87J11 FAMILY
Flexible Oscillator Structure:
Four Crystal modes, including High-Precision PLL
Two External Clock modes, up to 48 MHz
Internal Oscillator Block:
- Provides 8 user-selectable frequencies from
31 kHz to 8 MHz
- Provides a complete range of clock speeds,
from 31 kHz to 32 MHz when used with PLL
- User-tunable to compensate for frequency drift
Secondary Oscillator using Timer1 @ 32 kHz
Fail-Safe Clock Monitor:
- Allows for safe shutdown if any clock stops
Peripheral Highlights:
High-Current Sink/Source 25 mA/25mA on PORTB
and PORTC
Four Programmable External Interrupts
Four Input Change Interrupts
One 8/16-Bit Timer/Counter
Two 8-Bit Timers/Counters
Two 16-Bit Timers/Counters
Two Capture/Compare/PWM (CCP) modules
Three Enhanced Capture/Compare/PWM (ECCP)
modules:
- One, two or four PWM outputs
- Selectable polarity
- Programmable dead time
- Auto-shutdown and auto-restart
Two Master Synchronous Serial Port (MSSP)
modules supporting 3-Wire SPI (all 4 modes) and
I2C™ Master and Slave modes
Two Enhanced USART modules:
- Supports RS-485, RS-232 and LIN 1.2
- Auto-wake-up on Start bit
- Auto-Baud Detect
Peripheral Highlights (continued):
8-Bit Parallel Master Port/Enhanced Parallel Slave
Port (PMP/EPSP) with 16 Address Lines
Dual Analog Comparators with Input Multiplexing
10-Bit, up to 15-Channel Analog-to-Digital Converter
module (A/D):
- Auto-acquisition capability
- Conversion available during Sleep
External Memory Bus
(80-pin devices only):
Address Capability of up to 2 Mbytes
8-Bit or 16-Bit Interface
12-Bit, 16-Bit and 20-Bit Addressing modes
Special Microcontroller Features:
Low-Power, High-Speed CMOS Flash Technology
C Compiler Optimized Architecture for Re-Entrant
Code
Power Management Features:
- Run: CPU on, peripherals on
- Idle: CPU off, peripherals on
- Sleep: CPU off, peripherals off
Priority Levels for Interrupts
Self-Programmable under Software Control
8 x 8 Single-Cycle Hardware Multiplier
Extended Watchdog Timer (WDT):
- Programmable period from 4 ms to 131s
Single-Supply In-Circuit Serial Programming™
(ICSP™) via Two Pins
In-Circuit Debug (ICD) with 3 Breakpoints via Two Pins
Operating Voltage Range of 2.0V to 3.6V
5.5V Tolerant Inputs (digital only pins)
On-Chip 2.5V Regulator
Flash Program Memory of 10000 Erase/Write
Cycles and 20-Year Data Retention
Device
Flash
Program
Memory
(bytes)
SRAM
Data
Memory
(bytes)
I/O 10-Bit
A/D (ch)
CCP/ECCP
(PWM)
MSSP
EUSART
Comparators
Timers
8/16-Bit
External Bus
PMP/EPSP
SPI Master
I2C™
PIC18F66J11 64 kB 3930 52 11 2/3 2 Y Y 2 2 2/3 N Y
PIC18F66J16 96 kB 3930 52 11 2/3 2 Y Y 2 2 2/3 N Y
PIC18F67J11 128 kB 3930 52 11 2/3 2 Y Y 2 2 2/3 N Y
PIC18F86J11 64 kB 3930 68 15 2/3 2 Y Y 2 2 2/3 Y Y
PIC18F86J16 96 kB 3930 68 15 2/3 2 Y Y 2 2 2/3 Y Y
PIC18F87J11 128 kB 3930 68 15 2/3 2 Y Y 2 2 2/3 Y Y
64/80-Pin High-Performance, 1-Mbit Flash Microcontrollers
with nanoWatt Technology
PIC18F87J11 FAMILY
DS39778C-page 2 Preliminary © 2008 Microchip Technology Inc.
Pin Diagrams
PIC18F6XJ11
1
2
3
4
5
6
7
8
9
10
11
12
13
14
38
37
36
35
34
33
50 49
17 18 19 20 21 22 23 24 25 26
RE2/PMBE/P2B
RE3/PMA13/P3C/REFO
RE4/PMA12/P3B
RE5/PMA11/P1C
RE6/PMA10/P1B
RE7/PMA9/ECCP2(1)/P2A(1)
RD0/PMD0
VDD
VSS
RD1/PMD1
RD2/PMD2
RD3/PMD3
RD4/PMD4/SDO2
RD5/PMD5/SDI2/SDA2
RD6/PMD6/SCK2/SCL2
RD7/PMD7/SS2
RE1/PMWR/P2C
RE0/PMRD/P2D
RG0/PMA8/ECCP3/P3A
RG1/PMA7/TX2/CK2
RG2/PMA6/RX2/DT2
RG3/PMCS1/CCP4/P3D
MCLR
RG4/PMCS2/CCP5/P1D
VSS
VDDCORE/VCAP
RF7/SS1
RF6/AN11/C1INA
RF5/AN10/C1INB/CVREF
RF4/AN9/C2INA
RF3/AN8/C2INB
RF2/PMA5/AN7/C1OUT
RB0/INT0/FLT0
RB1/INT1/PMA4
RB2/INT2/PMA3
RB3/INT3/PMA2
RB4/KBI0/PMA1
RB5/KBI1/PMA0
RB6/KBI2/PGC
VSS
OSC2/CLKO/RA6
OSC1/CLKI/RA7
VDD
RB7/KBI3/PGD
RC4/SDI1/SDA1
RC3/SCK1/SCL1
RC2/ECCP1/P1A
ENVREG
RF1/AN6/C2OUT
AVDD
AVSS
RA3/AN3/VREF+
RA2/AN2/VREF-
RA1/AN1
RA0/AN0
VSS
VDD
RA4/T0CKI
RA5/AN4
RC1/T1OSI/ECCP2(1)/P2A(1)
RC0/T1OSO/T13CKI
RC7/RX1/DT1
RC6/TX1/CK1
RC5/SDO1
15
16
31
40
39
27 28 29 30 32
48
47
46
45
44
43
42
41
54 53 52 5158 57 56 5560 59
64 63 62 61
64-Pin TQFP
Note 1: The ECCP2/P2A pin placement depends on the CCP2MX Configuration bit setting.
PIC18F6XJ16
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 3
PIC18F87J11 FAMILY
Pin Diagrams (Continued
PIC18F8XJ11
3
4
5
6
7
8
9
10
11
12
13
14
15
16
48
47
46
45
44
43
42
41
4039
64 63 62 61
21 22 23 24 25 26 27 28 29 30 31 32
RE2/AD10/PMBE(3)/P2B
RE3/AD11/PMA13/P3C(2)/REFO
RE4/AD12/PMA12/P3B(2)
RE5/AD13/PMA11/P1C(2)
RE6/AD14/PMA10/P1B(2)
RE7/AD15/PMA9/ECCP2(1)/P2A(1)
RD0/AD0/PMD0(3)
VDD
VSS
RD1/AD1/PMD1(3)
RD2/AD2/PMD2(3)
RD3/AD3/PMD3(3)
RD4/AD4/PMD4(3)/SDO2
RD5/AD5/PMD5(3)/SDI2/SDA2
RD6/AD6/PMD6(3)/SCK2/SCL2
RD7/AD7/PMD7(3)/SS2
RE1/AD9/PMWR(3)/P2C
RE0/AD8/PMRD(3)/P2D
RG0/PMA8/ECCP3/P3A
RG1/PMA7/TX2/CK2
RG2/PMA6/RX2/DT2
RG3/PMCS1/CCP4/P3D
MCLR
RG4/PMCS2/CCP5/P1D
VSS
VDDCORE/VCAP
RF7/PMD0(3)/SS1
RB0/INT0/FLT0
RB1/INT1/PMA4
RB2/INT2/PMA3
RB3/INT3/PMA2/ECCP2(1)/P2A(1)
RB4/KBI0/PMA1
RB5/KBI1/PMA0
RB6/KBI2/PGC
VSS
OSC2/CLKO/RA6
OSC1/CLKI/RA7
VDD
RB7/KBI3/PGD
RC4/SDI1/SDA1
RC3/SCK1/SCL1
RC2/ECCP1/P1A
ENVREG
RF1/AN6/C2OUT
AVDD
AVSS
RA3/AN3/VREF+
RA2/AN2/VREF-
RA1/AN1
RA0/AN0
VSS
VDD
RA4/PMD5(3)/T0CKI
RA5/PMD4(3)/AN4
RC1/T1OSI/ECCP2(1)/P2A(1)
RC0/T1OSO/T13CKI
RC7/RX1/DT1
RC6/TX1/CK1
RC5/SDO1
RJ0/ALE
RJ1/OE
RH1/A17
RH0/A16
1
2
RH2/A18/PMD7(3)
RH3/A19/PMD6(3)
17
18
RH7/PMWR(3)/AN15/P1B(2)
RH6/PMRD(3)/AN14/
RH5/PMBE(3)/AN13/P3B(2)/C2IND
RH4/PMD3(3)/AN12/P3C(2)/C2INC
RJ5/CE
RJ4/BA0
37
RJ7/UB
RJ6/LB
50
49
RJ2/WRL
RJ3/WRH
19
20 33 34 35 36 38
58
57
56
55
54
53
52
51
60
59
68 67 66 6572 71 70 6974 7378 77 76 757980
80-Pin TQFP
Note 1: The ECCP2/P2A pin placement depends on the CCP2MX Configuration bit and Processor mode settings.
2: P1B, P1C, P3B, and P3C pin placement depends on the ECCPMX Configuration bit setting.
3: PMP pin placement depends on the PMPMX Configuration bit setting.
RF5/PMD2(3)/AN10/
RF4/AN9/C2INA
RF3/AN8/C2INB
RF2/PMA5/AN7/C1OUT
RF6/PMD1(3)/AN11/C1INA
C1INB/CVREF
P1C(2)/C1INC
PIC18F8XJ16
PIC18F87J11 FAMILY
DS39778C-page 4 Preliminary © 2008 Microchip Technology Inc.
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 7
2.0 Oscillator Configurations ............................................................................................................................................................ 31
3.0 Power-Managed Modes ............................................................................................................................................................. 41
4.0 Reset .......................................................................................................................................................................................... 49
5.0 Memory Organization ................................................................................................................................................................. 61
6.0 Flash Program Memory.............................................................................................................................................................. 87
7.0 External Memory Bus ................................................................................................................................................................. 97
8.0 8 x 8 Hardware Multiplier.......................................................................................................................................................... 109
9.0 Interrupts .................................................................................................................................................................................. 111
10.0 I/O Ports ................................................................................................................................................................................... 127
11.0 Parallel Master Port.................................................................................................................................................................. 151
12.0 Timer0 Module ......................................................................................................................................................................... 177
13.0 Timer1 Module ......................................................................................................................................................................... 181
14.0 Timer2 Module ......................................................................................................................................................................... 187
15.0 Timer3 Module ......................................................................................................................................................................... 189
16.0 Timer4 Module ......................................................................................................................................................................... 193
17.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 195
18.0 Enhanced Capture/Compare/PWM (ECCP) Module................................................................................................................ 203
19.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 221
20.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................................... 269
21.0 10-bit Analog-to-Digital Converter (A/D) Module ...................................................................................................................... 291
22.0 Comparator Module.................................................................................................................................................................. 301
23.0 Comparator Voltage Reference Module ................................................................................................................................... 309
24.0 Special Features of the CPU.................................................................................................................................................... 313
25.0 Instruction Set Summary .......................................................................................................................................................... 329
26.0 Development Support............................................................................................................................................................... 379
27.0 Electrical Characteristics .......................................................................................................................................................... 383
28.0 Packaging Information.............................................................................................................................................................. 423
Appendix A: Revision History............................................................................................................................................................. 429
Appendix B: Device Differences......................................................................................................................................................... 429
The Microchip Web Site..................................................................................................................................................................... 431
Customer Change Notification Service .............................................................................................................................................. 431
Customer Support .............................................................................................................................................................................. 431
Reader Response .............................................................................................................................................................................. 432
Product Identification System............................................................................................................................................................. 445
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 5
PIC18F87J11 FAMILY
TO OUR VALUED CUSTOMERS
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The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000).
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An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current
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To determine if an errata sheet exists for a particular device, please check with one of the following:
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PIC18F87J11 FAMILY
DS39778C-page 6 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 7
PIC18F87J11 FAMILY
1.0 DEVICE OVERVIEW
This document contains device-specific information for
the following devices:
This family introduces a line of low-voltage, general
purpose microcontrollers with the main traditional
advantage of all PIC18 microcontrollers – namely, high
computational performance and a rich feature set – at
an extremely competitive price point. These features
make the PIC18F87J11 Family a logical choice for
many high-performance applications, where an
extended peripheral feature set is required, and cost is
a primary consideration.
1.1 Core Features
1.1.1 nanoWatt TECHNOLOGY
All of the devices in the PIC18F87J11 family incorporate
a range of features that can significantly reduce power
consumption during operation. Key items include:
Alternate Run Modes: By clocking the controller
from the Timer1 source or the internal RC oscilla-
tor, power consumption during code execution
can be reduced by as much as 90%.
Multiple Idle Modes: The controller can also run
with its CPU core disabled but the peripherals still
active. In these states, power consumption can be
reduced even further, to as little as 4% of normal
operation requirements.
On-the-Fly Mode Switching: The
power-managed modes are invoked by user code
during operation, allowing the user to incorporate
power-saving ideas into their application’s
software design.
1.1.2 OSCILLATOR OPTIONS AND
FEATURES
All of the devices in the PIC18F87J11 Family offer four
different oscillator options, allowing users a range of
choices in developing application hardware. These
include:
Two Crystal modes, using crystals or ceramic
resonators.
Two External Clock modes, offering the option of
a divide-by-4 clock output.
An internal oscillator block which provides an
8 MHz clock and an INTRC source (approxi-
mately 31 kHz, stable over temperature and VDD),
as well as a range of 6 user-selectable clock
frequencies, between 125 kHz to 4 MHz, for a
total of 8 clock frequencies. This option frees an
oscillator pin for use as an additional general
purpose I/O.
A Phase Lock Loop (PLL) frequency multiplier,
available to all of the oscillator modes, which
allows a wide range of clock speeds from 16 MHz
to 40 MHz
The internal oscillator block provides a stable reference
source that gives the family additional features for
robust operation:
Fail-Safe Clock Monitor: This option constantly
monitors the main clock source against a reference
signal provided by the internal oscillator. If a clock
failure occurs, the controller is switched to the
internal oscillator, allowing for continued low-speed
operation or a safe application shutdown.
Two-Speed Start-up: This option allows the
internal oscillator to serve as the clock source
from Power-on Reset, or wake-up from Sleep
mode, until the primary clock source is available.
1.1.3 EXPANDED MEMORY
The PIC18F87J11 family provides ample room for
application code, from 64 Kbytes to 128 Kbytes of code
space. The Flash cells for program memory are rated
to last up to 10,000 erase/write cycles. Data retention
without refresh is conservatively estimated to be
greater than 20 years.
The Flash program memory is readable, writable, and
during normal operation, the PIC18F87J11 Family also
provides plenty of room for dynamic application data
with up to 3930 bytes of data RAM.
1.1.4 EXTERNAL MEMORY BUS
In the event that 128 Kbytes of memory are inadequate
for an application, the 80-pin members of the
PIC18F87J11 Family also implement an External Mem-
ory Bus (EMB). This allows the controller’s internal
program counter to address a memory space of up to
2 Mbytes, permitting a level of data access that few
8-bit devices can claim. This allows additional memory
options, including:
Using combinations of on-chip and external
memory up to the 2-Mbyte limit
Using external Flash memory for reprogrammable
application code or large data tables
Using external RAM devices for storing large
amounts of variable data
1.1.5 EXTENDED INSTRUCTION SET
The PIC18F87J11 Family implements the optional
extension to the PIC18 instruction set, adding 8 new
instructions and an Indexed Addressing mode.
Enabled as a device configuration option, the extension
has been specifically designed to optimize re-entrant
application code originally developed in high-level
languages, such as ‘C’.
PIC18F66J11 PIC18F86J11
PIC18F66J16 PIC18F86J16
PIC18F67J11 PIC18F87J11
PIC18F87J11 FAMILY
DS39778C-page 8 Preliminary © 2008 Microchip Technology Inc.
1.1.6 EASY MIGRATION
Regardless of the memory size, all devices share the
same rich set of peripherals, allowing for a smooth
migration path as applications grow and evolve.
The consistent pinout scheme used throughout the
entire family also aids in migrating to the next larger
device. This is true when moving between the 64-pin
members, between the 80-pin members, or even
jumping from 64-pin to 80-pin devices.
The PIC18F87J11 Family is also pin compatible with
other PIC18 families, such as the PIC18F87J10,
PIC18F85J11, PIC18F8720 and PIC18F8722. This
allows a new dimension to the evolution of applications,
allowing developers to select different price points
within Microchip’s PIC18 portfolio, while maintaining
the same feature set.
1.2 Other Special Features
Communications: The PIC18F87J11 Family
incorporates a range of serial and parallel com-
munication peripherals. These devices all include
2 independent Enhanced USARTs and 2 Master
SSP modules, capable of both SPI and I2C™
(Master and Slave) modes of operation. The
devices also have a parallel port and can be
configured to function as either a Parallel Master
Port or as a Parallel Slave Port.
CCP Modules: All devices in the family incorporate
two Capture/Compare/PWM (CCP) modules and
three Enhanced CCP (ECCP) modules to maximize
flexibility in control applications. Up to four different
time bases may be used to perform several
different operations at once. Each of the three
ECCP modules offers up to four PWM outputs,
allowing for a total of 12 PWMs. The ECCPs also
offer many beneficial features, including polarity
selection, programmable dead time, auto-shutdown
and restart, and Half-Bridge and Full-Bridge Output
modes.
10-Bit A/D Converter: This module incorporates
programmable acquisition time, allowing for a
channel to be selected and a conversion to be
initiated without waiting for a sampling period, and
thus, reducing code overhead.
Extended Watchdog Timer (WDT): This
enhanced version incorporates a 16-bit prescaler,
allowing an extended time-out range that is stable
across operating voltage and temperature. See
Section 27.0 “Electrical Characteristics” for
time-out periods.
1.3 Details on Individual Family
Members
Devices in the PIC18F87J11 Family are available in
64-pin and 80-pin packages. Block diagrams for the
two groups are shown in Figure 1-1 and Figure 1-2.
The devices are differentiated from each other in three
ways:
1. Flash program memory (three sizes, ranging
from 64 Kbytes for PIC18FX6J11 devices to
128 Kbytes for PIC18FX7J11 devices).
2. I/O ports (7 bidirectional ports on 64-pin devices,
9 bidirectional ports on 80-pin devices).
3. A/D input channels (11 on 64-pin devices, 15 on
80-pin devices).
All other features for devices in this family are identical.
These are summarized in Table 1-1 and Table 1-2.
The pinouts for all devices are listed in Table 1-3 and
Table 1-4.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 9
PIC18F87J11 FAMILY
TABLE 1-1: DEVICE FEATURES FOR THE PIC18F6XJ1X (64-PIN DEVICES)
TABLE 1-2: DEVICE FEATURES FOR THE PIC18F8XJ1X (80-PIN DEVICES)
Features PIC18F66J11 PIC18F66J16 PIC18F67J11
Operating Frequency DC – 48 MHz DC – 48 MHz DC – 48 MHz
Program Memory (Bytes) 64K 96K 128K
Program Memory (Instructions) 32768 49152 65536
Data Memory (Bytes) 3930 3930 3930
Interrupt Sources 29
I/O Ports Ports A, B, C, D, E, F, G
Timers 5
Capture/Compare/PWM Modules 2
Enhanced Capture/Compare/PWM Modules 3
Serial Communications MSSP (2), Enhanced USART (2)
Parallel Communications (PMP) Yes
10-Bit Analog-to-Digital Module 11 Input Channels
Resets (and Delays) POR, BOR, RESET Instruction, Stack Full, Stack Underflow, MCLR, WDT
(PWRT, OST)
Instruction Set 75 Instructions, 83 with Extended Instruction Set Enabled
Packages 64-Pin TQFP
Features PIC18F86J11 PIC18F86J16 PIC18F87J11
Operating Frequency DC – 48 MHz DC – 48 MHz DC – 48 MHz
Program Memory (Bytes) 64K 96K 128K
Program Memory (Instructions) 32768 49152 65536
Data Memory (Bytes) 3930 3930 3930
Interrupt Sources 29
I/O Ports Ports A, B, C, D, E, F, G, H, J
Timers 5
Capture/Compare/PWM Modules 2
Enhanced Capture/Compare/PWM Modules 3
Serial Communications MSSP (2), Enhanced USART (2)
Parallel Communications (PMP) Yes
10-Bit Analog-to-Digital Module 15 Input Channels
Resets (and Delays) POR, BOR, RESET Instruction, Stack Full, Stack Underflow, MCLR, WDT
(PWRT, OST)
Instruction Set 75 Instructions, 83 with Extended Instruction Set Enabled
Packages 80-Pin TQFP
PIC18F87J11 FAMILY
DS39778C-page 10 Preliminary © 2008 Microchip Technology Inc.
FIGURE 1-1: PIC18F6XJ1X (64-PIN) BLOCK DIAGRAM
Instruction
Decode and
Control
PORTA
Data Latch
Data Memory
(2.0, 3.9
Address Latch
Data Address<12>
12
Access
BSR FSR0
FSR1
FSR2
inc/dec
logic
Address
412 4
PCH PCL
PCLATH
8
31 Level Stack
Program Counter
PRODLPRODH
8 x 8 Multiply
8
BITOP
8
8
ALU<8>
Address Latch
Program Memory
(96 Kbytes)
Data Latch
20
8
8
Table Pointer<21>
inc/dec logic
21
8
Data Bus<8>
Table Latch
8
IR
12
3
PCLATU
PCU
Note 1: See Table 1-3 for I/O port pin descriptions.
2: BOR functionality is provided when the on-board voltage regulator is enabled.
EUSART1
Comparators
MSSP1
Timer2Timer1 Timer3Timer0
ECCP1
ADC
10-Bit
W
Instruction Bus <16>
STKPTR Bank
8
State Machine
Control Signals
Decode
8
8
EUSART2
ECCP2
ROM Latch
ECCP3 MSSP2CCP4 CCP5
PORTC
PORTD
PORTE
PORTF
PORTG
RA0:RA7(1)
RC0:RC7(1)
RD0:RD7(1)
RE0:RE7(1)
RF2:RF7(1)
RG0:RG4(1)
PORTB
RB0:RB7(1)
Timer4
OSC1/CLKI
OSC2/CLKO
VDD,
8 MHz
INTOSC
VSS MCLR
Power-up
Timer
Oscillator
Start-up Timer
Power-on
Reset
Watchdog
Timer
Brown-out
Reset(2)
Precision
Reference
Band Gap
INTRC
Oscillator
Regulator
Voltage
VDDCORE/VCAP
ENVREG
Kbytes)
PMP
Timing
Generation
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 11
PIC18F87J11 FAMILY
FIGURE 1-2: PIC18F8XJ1X (80-PIN) BLOCK DIAGRAM
PRODLPRODH
8 x 8 Multiply
8
BITOP
8
8
ALU<8>
8
8
3
W8
8
8
Instruction
Decode &
Control
Data Latch
Address Latch
Data Address<12>
12
Access
BSR FSR0
FSR1
FSR2
inc/dec
logic
Address
412 4
PCH PCL
PCLATH
8
31 Level Stack
Program Counter
Address Latch
Program Memory
(128 Kbytes)
Data Latch
20
Table Pointer<21>
inc/dec logic
21
8
Data Bus<8>
Tab l e Lat c h
8
IR
12
ROM Latch
PCLATU
PCU
Instruction Bus <16>
STKPTR Bank
State Machine
Control Signals
Decode
System Bus Interface
AD15:AD0, A19:A16
(Multiplexed with PORTD,
PORTE and PORTH)
PORTA
PORTC
PORTD
PORTE
PORTF
PORTG
RA0:RA7(1)
RC0:RC7(1)
RD0:RD7(1)
RE0:RE7(1)
RF2:RF7(1)
RG0:RG4(1)
PORTB
RB0:RB7(1)
PORTH
RH0:RH7(1)
PORTJ
RJ0:RJ7(1)
EUSART1
Comparators
MSSP1
Timer2Timer1 Timer3Timer0
ECCP1
ADC
10-Bit
EUSART2
ECCP2 ECCP3 MSSP2CCP4 CCP5
Timer4
Note 1: See Table 1-4 for I/O port pin descriptions.
2: BOR functionality is provided when the on-board voltage regulator is enabled.
Data Memory
(2.0, 3.9
Kbytes)
PMP
OSC1/CLKI
OSC2/CLKO
VDD,
8 MHz
INTOSC
VSS MCLR
Power-up
Timer
Oscillator
Start-up Timer
Power-on
Reset
Watchdog
Timer
Brown-out
Reset(2)
Precision
Reference
Band Gap
INTRC
Oscillator
Regulator
Voltage
VDDCORE/VCAP
ENVREG
Timing
Generation
PIC18F87J11 FAMILY
DS39778C-page 12 Preliminary © 2008 Microchip Technology Inc.
TABLE 1-3: PIC18F6XJ1X PINOUT I/O DESCRIPTIONS
Pin Name
Pin Number Pin
Type
Buffer
Type Description
64-TQFP
MCLR 7 I ST Master Clear (Reset) input. This pin is an active-low Reset
to the device.
OSC1/CLKI/RA7
OSC1
CLKI
RA7
39
I
I
I/O
ST
CMOS
TTL
Oscillator crystal or external clock input. Available only in
external oscillator modes (EC/ECPLL and HS/HSPLL).
Main oscillator input connection.
Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode; CMOS
otherwise.
Main clock input connection.
External clock source input. Always associated
with pin function OSC1. (See related OSC1/CLKI,
OSC2/CLKO pins.)
General purpose I/O pin. Available only in INTIO2 and
INTPLL2 Oscillator modes.
OSC2/CLKO/RA6
OSC2
CLKO
RA6
40
O
O
I/O
TTL
Oscillator crystal or clock output. Available only in external
oscillator modes (EC/ECPLL and HS/HSPLL).
Main oscillator feedback output connection.
Oscillator crystal output. Connects to crystal or
resonator in Crystal Oscillator mode.
System cycle clock output (FOSC/4).
In EC, ECPLL, INTIO1 and INTPLL1 Oscillator modes,
OSC2 pin outputs CLKO which has 1/4 the frequency
of OSC1 and denotes the instruction cycle rate.
General purpose I/O pin. Available only in INTIO1 and
INTPLL1 Oscillator modes.
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Default assignment for ECCP2/P2A when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 13
PIC18F87J11 FAMILY
PORTA is a bidirectional I/O port.
RA0/AN0
RA0
AN0
24
I/O
I
TTL
Analog
Digital I/O.
Analog input 0.
RA1/AN1
RA1
AN1
23
I/O
I
TTL
Analog
Digital I/O.
Analog input 1.
RA2/AN2/VREF-
RA2
AN2
VREF-
22
I/O
I
I
TTL
Analog
Analog
Digital I/O.
Analog input 2.
A/D reference voltage (low) input.
RA3/AN3/VREF+
RA3
AN3
VREF+
21
I/O
I
I
TTL
Analog
Analog
Digital I/O.
Analog input 3.
A/D reference voltage (high) input.
RA4/T0CKI
RA4
T0CKI
28
I/O
I
ST
ST
Digital I/O.
Timer0 external clock input.
RA5/AN4
RA5
AN4
27
I/O
I
TTL
Analog
Digital I/O.
Analog input 4.
RA6 See the OSC2/CLKO/RA6 pin.
RA7 See the OSC1/CLKI/RA7 pin.
TABLE 1-3: PIC18F6XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
64-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Default assignment for ECCP2/P2A when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared.
PIC18F87J11 FAMILY
DS39778C-page 14 Preliminary © 2008 Microchip Technology Inc.
PORTB is a bidirectional I/O port. PORTB can be software
programmed for internal weak pull-ups on all inputs.
RB0/FLT0/INT0
RB0
FLT0
INT0
48
I/O
I
I
TTL
ST
ST
Digital I/O.
ECCP1/2/3 Fault input.
External interrupt 0.
RB1/INT1/PMA4
RB1
INT1
PMA4
47
I/O
I
O
TTL
ST
Digital I/O.
External interrupt 1.
Parallel Master Port address.
RB2/INT2/PMA3
RB2
INT2
PMA3
46
I/O
I
O
TTL
ST
Digital I/O.
External interrupt 2.
Parallel Master Port address.
RB3/INT3/PMA2
RB3
INT3
PMA2
45
I/O
I
O
TTL
ST
Digital I/O.
External interrupt 3.
Parallel Master Port address.
RB4/KBI0/PMA1
RB4
KBI0
PMA1
44
I/O
I
I/O
TTL
TTL
Digital I/O.
Interrupt-on-change pin.
Parallel Master Port address.
RB5/KBI1/PMA0
RB5
KBI1
PMA0
43
I/O
I
I/O
TTL
TTL
Digital I/O.
Interrupt-on-change pin.
Parallel Master Port address.
RB6/KBI2/PGC
RB6
KBI2
PGC
42
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP™ programming
clock pin.
RB7/KBI3/PGD
RB7
KBI3
PGD
37
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming data pin.
TABLE 1-3: PIC18F6XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
64-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Default assignment for ECCP2/P2A when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 15
PIC18F87J11 FAMILY
PORTC is a bidirectional I/O port.
RC0/T1OSO/T13CKI
RC0
T1OSO
T13CKI
30
I/O
O
I
ST
ST
Digital I/O.
Timer1 oscillator output.
Timer1/Timer3 external clock input.
RC1/T1OSI/ECCP2/P2A
RC1
T1OSI
ECCP2(1)
P2A(1)
29
I/O
I
I/O
O
ST
CMOS
ST
Digital I/O.
Timer1 oscillator input.
Capture 2 input/Compare 2 output/PWM2 output.
ECCP2 PWM output A.
RC2/ECCP1/P1A
RC2
ECCP1
P1A
33
I/O
I/O
O
ST
ST
Digital I/O.
Capture 1 input/Compare 1 output/PWM1 output.
ECCP1 PWM output A.
RC3/SCK1/SCL1
RC3
SCK1
SCL1
34
I/O
I/O
I/O
ST
ST
ST
Digital I/O.
Synchronous serial clock input/output for SPI mode.
Synchronous serial clock input/output for I2C™ mode.
RC4/SDI1/SDA1
RC4
SDI1
SDA1
35
I/O
I
I/O
ST
ST
ST
Digital I/O.
SPI data in.
I2C data I/O.
RC5/SDO1
RC5
SDO1
36
I/O
O
ST
Digital I/O.
SPI data out.
RC6/TX1/CK1
RC6
TX1
CK1
31
I/O
O
I/O
ST
ST
Digital I/O.
EUSART1 asynchronous transmit.
EUSART1 synchronous clock (see related RX1/DT1).
RC7/RX1/DT1
RC7
RX1
DT1
32
I/O
I
I/O
ST
ST
ST
Digital I/O.
EUSART1 asynchronous receive.
EUSART1 synchronous data (see related TX1/CK1).
TABLE 1-3: PIC18F6XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
64-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Default assignment for ECCP2/P2A when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared.
PIC18F87J11 FAMILY
DS39778C-page 16 Preliminary © 2008 Microchip Technology Inc.
PORTD is a bidirectional I/O port.
RD0/PMD0
RD0
PMD0
58
I/O
I/O
ST
TTL
Digital I/O.
Parallel Master Port data.
RD1/PMD1
RD1
PMD1
55
I/O
I/O
ST
TTL
Digital I/O.
Parallel Master Port data.
RD2/PMD2
RD2
PMD2
54
I/O
I/O
ST
TTL
Digital I/O.
Parallel Master Port data.
RD3/PMD3
RD3
PMD3
53
I/O
I/O
ST
TTL
Digital I/O.
Parallel Master Port data.
RD4/PMD4/SDO2
RD4
PMD4
SDO2
52
I/O
I/O
O
ST
TTL
Digital I/O.
Parallel Master Port data.
SPI data out.
RD5/PMD5/SDI2/SDA2
RD5
PMD5
SDI2
SDA2
51
I/O
I/O
I
I/O
ST
TTL
ST
ST
Digital I/O.
Parallel Master Port data.
SPI data in.
I2C™ data I/O.
RD6/PMD6/SCK2/SCL2
RD6
PMD6
SCK2
SCL2
50
I/O
I/O
I/O
I/O
ST
TTL
ST
ST
Digital I/O.
Parallel Master Port data.
Synchronous serial clock input/output for SPI mode.
Synchronous serial clock input/output for I2C mode.
RD7/PMD7/SS2
RD7
PMD7
SS2
49
I/O
I/O
I
ST
TTL
TTL
Digital I/O.
Parallel Master Port data.
SPI slave select input.
TABLE 1-3: PIC18F6XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
64-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Default assignment for ECCP2/P2A when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 17
PIC18F87J11 FAMILY
PORTE is a bidirectional I/O port.
RE0/PMRD/P2D
RE0
PMRD
P2D
2
I/O
I/O
O
ST
Digital I/O.
Parallel Master Port read strobe.
ECCP2 PWM output D.
RE1/PMWR/P2C
RE1
PMWR
P2C
1
I/O
I/O
O
ST
Digital I/O.
Parallel Master Port write strobe.
ECCP2 PWM output C.
RE2/PMBE/P2B
RE2
PMBE
P2B
64
I/O
O
O
ST
Digital I/O.
Parallel Master Port byte enable
ECCP2 PWM output B.
RE3/PMA13/P3C/REFO
RE3
PMA13
P3C
REFO
63
I/O
O
O
O
ST
Digital I/O.
Parallel Master Port address.
ECCP3 PWM output C.
Reference clock out.
RE4/PMA12/P3B
RE4
PMA12
P3B
62
I/O
O
O
ST
Digital I/O.
Parallel Master Port address.
ECCP3 PWM output B.
RE5/PMA11/P1C
RE5
PMA11
P1C
61
I/O
O
O
ST
Digital I/O.
Parallel Master Port address.
ECCP1 PWM output C.
RE6/PMA10/P1B
RE6
PMA10
P1B
60
I/O
O
O
ST
Digital I/O.
Parallel Master Port address.
ECCP1 PWM output B.
RE7/PMA9/ECCP2/P2A
RE7
PMA9
ECCP2(2)
P2A(2)
59
I/O
O
I/O
O
ST
ST
Digital I/O.
Parallel Master Port address.
Capture 2 input/Compare 2 output/PWM2 output.
ECCP2 PWM output A.
TABLE 1-3: PIC18F6XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
64-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Default assignment for ECCP2/P2A when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared.
PIC18F87J11 FAMILY
DS39778C-page 18 Preliminary © 2008 Microchip Technology Inc.
PORTF is a bidirectional I/O port.
RF1/AN6/C2OUT
RF1
AN6
C2OUT
17
I/O
I
O
ST
Analog
Digital I/O.
Analog input 6.
Comparator 2 output.
RF2/PMA5/AN7/C1OUT
RF2
PMA5
AN7
C1OUT
16
I/O
O
I
O
ST
Analog
Digital I/O.
Parallel Master Port address.
Analog input 7.
Comparator 1 output.
RF3/AN8/C2INB
RF3
AN8
C2INB
15
I
I
I
ST
Analog
Analog
Digital input.
Analog input 8.
Comparator 2 input B.
RF4/AN9/C2INA
RF4
AN9
C2INA
14
I
I
I
ST
Analog
Analog
Digital input.
Analog input 8.
Comparator 2 input A.
RF5/AN10/C1INB/CVREF
RF5
AN10
C1INB
CVREF
13
I
I
I
O
ST
Analog
Analog
Analog
Digital input.
Analog input 10.
Comparator 1 input B.
Comparator reference voltage output.
RF6/AN11/C1INA
RF6
AN11
C1INA
12
I/O
I
I
ST
Analog
Analog
Digital I/O.
Analog input 11.
Comparator 1 input A.
RF7/SS1
RF7
SS1
11
I/O
I
ST
TTL
Digital I/O.
SPI slave select input.
TABLE 1-3: PIC18F6XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
64-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Default assignment for ECCP2/P2A when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 19
PIC18F87J11 FAMILY
PORTG is a bidirectional I/O port.
RG0/PMA8/ECCP3/P3A
RG0
PMA8
ECCP3
P3A
3
I/O
O
I/O
O
ST
ST
Digital I/O.
Parallel Master Port address.
Capture 3 input/Compare 3 output/PWM3 output.
ECCP3 PWM output A.
RG1/PMA7/TX2/CK2
RG1
PMA7
TX2
CK2
4
I/O
O
O
I/O
ST
ST
Digital I/O.
Parallel Master Port address.
EUSART2 asynchronous transmit.
EUSART2 synchronous clock (see related RX2/DT2).
RG2/PMA6/RX2/DT2
RG2
PMA6
RX2
DT2
5
I/O
O
I
I/O
ST
ST
ST
Digital I/O.
Parallel Master Port address.
EUSART2 asynchronous receive.
EUSART2 synchronous data (see related TX2/CK2).
RG3/PMCS1/CCP4/P3D
RG3
PMCS1
CCP4
P3D
6
I/O
O
I/O
O
ST
ST
Digital I/O.
Parallel Master Port chip select 1.
Capture 4 input/Compare 4 output/PWM4 output.
ECCP3 PWM output D.
RG4/PMCS2/CCP5/P1D
RG4
PMCS2
CCP5
P1D
8
I/O
O
I/O
O
ST
ST
Digital I/O.
Parallel Master Port chip select 2.
Capture 5 input/Compare 5 output/PWM5 output.
ECCP1 PWM output D.
VSS 9, 25, 41, 56 P Ground reference for logic and I/O pins.
VDD 26, 38, 57 P Positive supply for peripheral digital logic and I/O pins.
AVss 20 P Ground reference for analog modules.
AVDD 19 P Positive supply for analog modules.
ENVREG 18 I ST Enable for on-chip voltage regulator.
VDDCORE/VCAP
VDDCORE
VCAP
10
P
P
Core logic power or external filter capacitor connection.
Positive supply for microcontroller core logic
(regulator disabled).
External filter capacitor connection (regulator
enabled).
TABLE 1-3: PIC18F6XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
64-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Default assignment for ECCP2/P2A when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared.
PIC18F87J11 FAMILY
DS39778C-page 20 Preliminary © 2008 Microchip Technology Inc.
TABLE 1-4: PIC18F8XJ1X PINOUT I/O DESCRIPTIONS
Pin Name
Pin Number Pin
Type
Buffer
Type Description
80-TQFP
MCLR 9 I ST Master Clear (Reset) input. This pin is an active-low Reset to
the device.
OSC1/CLKI/RA7
OSC1
CLKI
RA7
49
I
I
I/O
ST
CMOS
TTL
Oscillator crystal or external clock input. Available only in
external oscillator modes (EC/ECPLL and HS/HSPLL).
Main oscillator input connection.
Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode; CMOS
otherwise.
Main clock input connection.
External clock source input. Always associated
with pin function OSC1. (See related OSC1/CLKI,
OSC2/CLKO pins.)
General purpose I/O pin. Available only in INTIO2 and
INTPLL2 Oscillator modes.
OSC2/CLKO/RA6
OSC2
CLKO
RA6
50
O
O
I/O
TTL
Oscillator crystal or clock output. Available only in external
oscillator modes (EC/ECPLL and HS/HSPLL).
Main oscillator feedback output connection.
Oscillator crystal output. Connects to crystal or
resonator in Crystal Oscillator mode.
System cycle clock output (FOSC/4).
In EC, ECPLL, INTIO1 and INTPLL1 Oscillator modes,
OSC2 pin outputs CLKO which has 1/4 the frequency
of OSC1 and denotes the instruction cycle rate.
General purpose I/O pin. Available only in INTIO and INTPLL
Oscillator modes.
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared (Extended Microcontroller mode).
2: Default assignment for ECCP2/P2A for all devices in all operating modes (CCP2MX is set).
3: Default assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is set).
4: Alternate assignment for ECCP2/P2A when CCP2MX is cleared (Microcontroller mode).
5: Alternate assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is cleared).
6: Default assignment for PMP data and control pins when PMPMX Configuration bit is set.
7: Alternate assignment for PMP data and control pins when PMPMX Configuration bit is cleared (programmed).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 21
PIC18F87J11 FAMILY
PORTA is a bidirectional I/O port.
RA0/AN0
RA0
AN0
30
I/O
I
TTL
Analog
Digital I/O.
Analog input 0.
RA1/AN1
RA1
AN1
29
I/O
I
TTL
Analog
Digital I/O.
Analog input 1.
RA2/AN2/VREF-
RA2
AN2
VREF-
28
I/O
I
I
TTL
Analog
Analog
Digital I/O.
Analog input 2.
A/D reference voltage (low) input.
RA3/AN3/VREF+
RA3
AN3
VREF+
27
I/O
I
I
TTL
Analog
Analog
Digital I/O.
Analog input 3.
A/D reference voltage (high) input.
RA4/PMD5/T0CKI
RA4
PMD5(7)
T0CKI
34
I/O
I/O
I
ST
TTL
ST
Digital I/O.
Parallel Master Port data.
Timer0 external clock input.
RA5/PMD4/AN4
RA5
PMD4(7)
AN4
33
I/O
I/O
I
TTL
TTL
Analog
Digital I/O.
Parallel Master Port data.
Analog input 4.
RA6 See the OSC2/CLKO/RA6 pin.
RA7 See the OSC1/CLKI/RA7 pin.
TABLE 1-4: PIC18F8XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
80-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared (Extended Microcontroller mode).
2: Default assignment for ECCP2/P2A for all devices in all operating modes (CCP2MX is set).
3: Default assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is set).
4: Alternate assignment for ECCP2/P2A when CCP2MX is cleared (Microcontroller mode).
5: Alternate assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is cleared).
6: Default assignment for PMP data and control pins when PMPMX Configuration bit is set.
7: Alternate assignment for PMP data and control pins when PMPMX Configuration bit is cleared (programmed).
PIC18F87J11 FAMILY
DS39778C-page 22 Preliminary © 2008 Microchip Technology Inc.
PORTB is a bidirectional I/O port. PORTB can be software
programmed for internal weak pull-ups on all inputs.
RB0/FLT0/INT0
RB0
FLT0
INT0
58
I/O
I
I
TTL
ST
ST
Digital I/O.
ECCP1/2/3 Fault input.
External interrupt 0.
RB1/INT1/PMA4
RB1
INT1
PMA4
57
I/O
I
O
TTL
ST
Digital I/O.
External interrupt 1.
Parallel Master Port address.
RB2/INT2/PMA3
RB2
INT2
PMA3
56
I/O
I
O
TTL
ST
Digital I/O.
External interrupt 2.
Parallel Master Port address.
RB3/INT3/PMA2/
ECCP2/P2A
RB3
INT3
PMA2
ECCP2(1)
P2A(1)
55
I/O
I
O
I/O
O
TTL
ST
ST
Digital I/O.
External interrupt 3.
Parallel Master Port address.
Capture 2 input/Compare 2 output/PWM2 output.
ECCP2 PWM output A.
RB4/KBI0/PMA1
RB4
KBI0
PMA1
54
I/O
I
I/O
TTL
TTL
Digital I/O.
Interrupt-on-change pin.
Parallel Master Port address.
RB5/KBI1/PMA0
RB5
KBI1
PMA0
53
I/O
I
I/O
TTL
TTL
Digital I/O.
Interrupt-on-change pin.
Parallel Master Port address.
RB6/KBI2/PGC
RB6
KBI2
PGC
52
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP™ programming clock pin.
RB7/KBI3/PGD
RB7
KBI3
PGD
47
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming data pin.
TABLE 1-4: PIC18F8XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
80-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared (Extended Microcontroller mode).
2: Default assignment for ECCP2/P2A for all devices in all operating modes (CCP2MX is set).
3: Default assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is set).
4: Alternate assignment for ECCP2/P2A when CCP2MX is cleared (Microcontroller mode).
5: Alternate assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is cleared).
6: Default assignment for PMP data and control pins when PMPMX Configuration bit is set.
7: Alternate assignment for PMP data and control pins when PMPMX Configuration bit is cleared (programmed).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 23
PIC18F87J11 FAMILY
PORTC is a bidirectional I/O port.
RC0/T1OSO/T13CKI
RC0
T1OSO
T13CKI
36
I/O
O
I
ST
ST
Digital I/O.
Timer1 oscillator output.
Timer1/Timer3 external clock input.
RC1/T1OSI/ECCP2/P2A
RC1
T1OSI
ECCP2(2)
P2A(2)
35
I/O
I
I/O
O
ST
CMOS
ST
Digital I/O.
Timer1 oscillator input.
Capture 2 input/Compare 2 output/PWM2 output.
ECCP2 PWM output A.
RC2/ECCP1/P1A
RC2
ECCP1
P1A
43
I/O
I/O
O
ST
ST
Digital I/O.
Capture 1 input/Compare 1 output/PWM1 output.
ECCP1 PWM output A.
RC3/SCK1/SCL1
RC3
SCK1
SCL1
44
I/O
I/O
I/O
ST
ST
ST
Digital I/O.
Synchronous serial clock input/output for SPI mode.
Synchronous serial clock input/output for I2C™ mode.
RC4/SDI1/SDA1
RC4
SDI1
SDA1
45
I/O
I
I/O
ST
ST
ST
Digital I/O.
SPI data in.
I2C data I/O.
RC5/SDO1
RC5
SDO1
46
I/O
O
ST
Digital I/O.
SPI data out.
RC6/TX1/CK1
RC6
TX1
CK1
37
I/O
O
I/O
ST
ST
Digital I/O.
EUSART1 asynchronous transmit.
EUSART1 synchronous clock (see related RX1/DT1).
RC7/RX1/DT1
RC7
RX1
DT1
38
I/O
I
I/O
ST
ST
ST
Digital I/O.
EUSART1 asynchronous receive.
EUSART1 synchronous data (see related TX1/CK1).
TABLE 1-4: PIC18F8XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
80-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared (Extended Microcontroller mode).
2: Default assignment for ECCP2/P2A for all devices in all operating modes (CCP2MX is set).
3: Default assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is set).
4: Alternate assignment for ECCP2/P2A when CCP2MX is cleared (Microcontroller mode).
5: Alternate assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is cleared).
6: Default assignment for PMP data and control pins when PMPMX Configuration bit is set.
7: Alternate assignment for PMP data and control pins when PMPMX Configuration bit is cleared (programmed).
PIC18F87J11 FAMILY
DS39778C-page 24 Preliminary © 2008 Microchip Technology Inc.
PORTD is a bidirectional I/O port.
RD0/AD0/PMD0
RD0
AD0
PMD0(6)
72
I/O
I/O
I/O
ST
TTL
TTL
Digital I/O.
External memory address/data 0.
Parallel Master Port data.
RD1/AD1/PMD1
RD1
AD1
PMD1(6)
69
I/O
I/O
I/O
ST
TTL
TTL
Digital I/O.
External memory address/data 1.
Parallel Master Port data.
RD2/AD2/PMD2
RD2
AD2
PMD2(6)
68
I/O
I/O
I/O
ST
TTL
TTL
Digital I/O.
External memory address/data 2.
Parallel Master Port data.
RD3/AD3/PMD3
RD3
AD3
PMD3(6)
67
I/O
I/O
I/O
ST
TTL
TTL
Digital I/O.
External memory address/data 3.
Parallel Master Port data.
RD4/AD4/PMD4/SDO2
RD4
AD4
PMD4(6)
SDO2
66
I/O
I/O
I/O
O
ST
TTL
TTL
Digital I/O.
External memory address/data 4.
Parallel Master Port data.
SPI data out.
RD5/AD5/PMD5/
SDI2/SDA2
RD5
AD5
PMD5(6)
SDI2
SDA2
65
I/O
I/O
I/O
I
I/O
ST
TTL
TTL
ST
ST
Digital I/O.
External memory address/data 5.
Parallel Master Port data.
SPI data in.
I2C™ data I/O.
RD6/AD6/PMD6/
SCK2/SCL2
RD6
AD6
PMD6(6)
SCK2
SCL2
64
I/O
I/O
I/O
I/O
I/O
ST
TTL
TTL
ST
ST
Digital I/O.
External memory address/data 6.
Parallel Master Port data.
Synchronous serial clock input/output for SPI mode.
Synchronous serial clock input/output for I2C mode.
RD7/AD7/PMD7/SS2
RD7
AD7
PMD7(6)
SS2
63
I/O
I/O
I/O
I
ST
TTL
TTL
TTL
Digital I/O.
External memory address/data 7.
Parallel Master Port data.
SPI slave select input.
TABLE 1-4: PIC18F8XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
80-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared (Extended Microcontroller mode).
2: Default assignment for ECCP2/P2A for all devices in all operating modes (CCP2MX is set).
3: Default assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is set).
4: Alternate assignment for ECCP2/P2A when CCP2MX is cleared (Microcontroller mode).
5: Alternate assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is cleared).
6: Default assignment for PMP data and control pins when PMPMX Configuration bit is set.
7: Alternate assignment for PMP data and control pins when PMPMX Configuration bit is cleared (programmed).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 25
PIC18F87J11 FAMILY
PORTE is a bidirectional I/O port.
RE0/AD8/PMRD/P2D
RE0
AD8
PMRD(6)
P2D
4
I/O
I/O
I/O
O
ST
TTL
Digital I/O.
External memory address/data 8.
Parallel Master Port read strobe.
ECCP2 PWM output D.
RE1/AD9/PMWR/P2C
RE1
AD9
PMWR(6)
P2C
3
I/O
I/O
I/O
O
ST
TTL
Digital I/O.
External memory address/data 9.
Parallel Master Port write strobe.
ECCP2 PWM output C.
RE2/AD10/PMBE/P2B
RE2
AD10
PMBE(6)
P2B
78
I/O
I/O
O
O
ST
TTL
Digital I/O.
External memory address/data 10.
Parallel Master Port byte enable.
ECCP2 PWM output B.
RE3/AD11/PMA13/P3C/REFO
RE3
AD11
PMA13
P3C(3)
REFO
77
I/O
I/O
O
O
O
ST
TTL
Digital I/O.
External memory address/data 11.
Parallel Master Port address.
ECCP3 PWM output C.
Reference clock out.
RE4/AD12/PMA12/P3B
RE4
AD12
PMA12
P3B(3)
76
I/O
I/O
O
O
ST
TTL
Digital I/O.
External memory address/data 12.
Parallel Master Port address.
ECCP3 PWM output B.
RE5/AD13/PMA11/P1C
RE5
AD13
PMA11
P1C(3)
75
I/O
I/O
O
O
ST
TTL
Digital I/O.
External memory address/data 13.
Parallel Master Port address.
ECCP1 PWM output C.
RE6/AD14/PMA10/P1B
RE6
AD14
PMA10
P1B(3)
74
I/O
I/O
O
O
ST
TTL
Digital I/O.
External memory address/data 14.
Parallel Master Port address.
ECCP1 PWM output B.
RE7/AD15/PMA9/ECCP2/P2A
RE7
AD15
PMA9
ECCP2(4)
P2A(4)
73
I/O
I/O
O
I/O
O
ST
TTL
ST
Digital I/O.
External memory address/data 15.
Parallel Master Port address.
Capture 2 input/Compare 2 output/PWM2 output.
ECCP2 PWM output A.
TABLE 1-4: PIC18F8XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
80-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared (Extended Microcontroller mode).
2: Default assignment for ECCP2/P2A for all devices in all operating modes (CCP2MX is set).
3: Default assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is set).
4: Alternate assignment for ECCP2/P2A when CCP2MX is cleared (Microcontroller mode).
5: Alternate assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is cleared).
6: Default assignment for PMP data and control pins when PMPMX Configuration bit is set.
7: Alternate assignment for PMP data and control pins when PMPMX Configuration bit is cleared (programmed).
PIC18F87J11 FAMILY
DS39778C-page 26 Preliminary © 2008 Microchip Technology Inc.
PORTF is a bidirectional I/O port.
RF1/AN6/C2OUT
RF1
AN6
C2OUT
23
I/O
I
O
ST
Analog
Digital I/O.
Analog input 6.
Comparator 2 output.
RF2/PMA5/AN7/C1OUT
RF2
PMA5
AN7
C1OUT
18
I/O
O
I
O
ST
Analog
Digital I/O.
Parallel Master Port address.
Analog input 7.
Comparator 1 output.
RF3/AN8/C2INB
RF3
AN8
C2INB
17
I
I
I
ST
Analog
Analog
Digital input.
Analog input 8.
Comparator 2 input B.
RF4/AN9/C2INA
RF4
AN9
C2INA
16
I
I
I
ST
Analog
Analog
Digital input.
Analog input 8.
Comparator 2 input A.
RF5/PMD2/AN10/
C1INB/CVREF
RF5
PMD2(7)
AN10
C1INB
CVREF
15
I/O
I/O
I
I
O
ST
TTL
Analog
Analog
Analog
Digital I/O.
Parallel Master Port address.
Analog input 10.
Comparator 1 input B.
Comparator reference voltage output.
RF6/PMD1/AN11/C1INA
RF6
PMD1(7)
AN11
C1INA
14
I/O
I/O
I
I
ST
TTL
Analog
Analog
Digital I/O.
Parallel Master Port address.
Analog input 11.
Comparator 1 input A.
RF7/PMD0/SS1
RF7
PMD0 (7)
SS1
13
I/O
I/O
I
ST
TTL
TTL
Digital I/O.
Parallel Master Port address.
SPI slave select input.
TABLE 1-4: PIC18F8XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
80-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared (Extended Microcontroller mode).
2: Default assignment for ECCP2/P2A for all devices in all operating modes (CCP2MX is set).
3: Default assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is set).
4: Alternate assignment for ECCP2/P2A when CCP2MX is cleared (Microcontroller mode).
5: Alternate assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is cleared).
6: Default assignment for PMP data and control pins when PMPMX Configuration bit is set.
7: Alternate assignment for PMP data and control pins when PMPMX Configuration bit is cleared (programmed).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 27
PIC18F87J11 FAMILY
PORTG is a bidirectional I/O port.
RG0/PMA8/ECCP3/P3A
RG0
PMA8
ECCP3
P3A
5
I/O
O
I/O
O
ST
ST
Digital I/O.
Parallel Master Port address.
Capture 3 input/Compare 3 output/PWM3 output.
ECCP3 PWM output A.
RG1/PMA7/TX2/CK2
RG1
PMA7
TX2
CK2
6
I/O
O
O
I/O
ST
ST
Digital I/O.
Parallel Master Port address.
EUSART2 asynchronous transmit.
EUSART2 synchronous clock (see related RX2/DT2).
RG2/PMA6/RX2/DT2
RG2
PMA6
RX2
DT2
7
I/O
I/O
I
I/O
ST
ST
ST
Digital I/O.
Parallel Master Port address.
EUSART2 asynchronous receive.
EUSART2 synchronous data (see related TX2/CK2).
RG3/PMCS1/CCP4/P3D
RG3
PMCS1
CCP4
P3D
8
I/O
I/O
I/O
O
ST
ST
Digital I/O.
Parallel Master Port chip select 1.
Capture 4 input/Compare 4 output/PWM4 output.
ECCP3 PWM output D.
RG4/PMCS2/CCP5/P1D
RG4
PMCS2
CCP5
P1D
10
I/O
O
I/O
O
ST
ST
Digital I/O.
Parallel Master Port chip select 2.
Capture 5 input/Compare 5 output/PWM5 output.
ECCP1 PWM output D.
TABLE 1-4: PIC18F8XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
80-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared (Extended Microcontroller mode).
2: Default assignment for ECCP2/P2A for all devices in all operating modes (CCP2MX is set).
3: Default assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is set).
4: Alternate assignment for ECCP2/P2A when CCP2MX is cleared (Microcontroller mode).
5: Alternate assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is cleared).
6: Default assignment for PMP data and control pins when PMPMX Configuration bit is set.
7: Alternate assignment for PMP data and control pins when PMPMX Configuration bit is cleared (programmed).
PIC18F87J11 FAMILY
DS39778C-page 28 Preliminary © 2008 Microchip Technology Inc.
PORTH is a bidirectional I/O port.
RH0/A16
RH0
A16
79
I/O
O
ST
TTL
Digital I/O.
External memory address/data 16.
RH1/A17
RH1
A17
80
I/O
O
ST
TTL
Digital I/O.
External memory address/data 17.
RH2/A18/PMD7
RH2
A18
PMD7(7)
1
I/O
O
I/O
ST
TTL
TTL
Digital I/O.
External memory address/data 18.
Parallel Master Port data.
RH3/A19/PMD6
RH3
A19
PMD6(7)
2
I/O
O
I/O
ST
TTL
TTL
Digital I/O.
External memory address/data 19.
Parallel Master Port data.
RH4/PMD3/AN12/
P3C/C2INC
RH4
PMD3(7)
AN12
P3C(5)
C2INC
22
I/O
I/O
I
O
I
ST
TTL
Analog
Analog
Digital I/O.
Parallel Master Port address.
Analog input 12.
ECCP3 PWM output C.
Comparator 2 input C.
RH5/PMBE/AN13/
P3B/C2IND
RH5
PMBE(7)
AN13
P3B(5)
C2IND
21
I/O
O
I
O
I
ST
Analog
Analog
Digital I/O.
Parallel Master Port byte enable.
Analog input 13.
ECCP3 PWM output B.
Comparator 2 input D.
RH6/PMRD/AN14/
P1C/C1INC
RH6
PMRD(7)
AN14
P1C(5)
C1INC
20
I/O
I/O
I
O
I
ST
Analog
Analog
Digital I/O.
Parallel Master Port read strobe.
Analog input 14.
ECCP1 PWM output C.
Comparator 1 input C.
RH7/PMWR/AN15/P1B
RH7
PMWR(7)
AN15
P1B(5)
19
I/O
I/O
I
O
ST
Analog
Digital I/O.
Parallel Master Port write strobe.
Analog input 15.
ECCP1 PWM output B.
TABLE 1-4: PIC18F8XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
80-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared (Extended Microcontroller mode).
2: Default assignment for ECCP2/P2A for all devices in all operating modes (CCP2MX is set).
3: Default assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is set).
4: Alternate assignment for ECCP2/P2A when CCP2MX is cleared (Microcontroller mode).
5: Alternate assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is cleared).
6: Default assignment for PMP data and control pins when PMPMX Configuration bit is set.
7: Alternate assignment for PMP data and control pins when PMPMX Configuration bit is cleared (programmed).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 29
PIC18F87J11 FAMILY
PORTJ is a bidirectional I/O port.
RJ0/ALE
RJ0
ALE
62
I/O
O
ST
Digital I/O.
External memory address latch enable.
RJ1/OE
RJ1
OE
61
I/O
O
ST
Digital I/O.
External memory output enable.
RJ2/WRL
RJ2
WRL
60
I/O
O
ST
Digital I/O.
External memory write low control.
RJ3/WRH
RJ3
WRH
59
I/O
O
ST
Digital I/O.
External memory write high control.
RJ4/BA0
RJ4
BA0
39
I/O
O
ST
Digital I/O.
External memory byte address 0 control.
RJ5/CE
RJ5
CE
40
I/O
O
ST
Digital I/O
External memory chip enable control.
RJ6/LB
RJ6
LB
41
I/O
O
ST
Digital I/O.
External memory low byte control.
RJ7/UB
RJ7
UB
42
I/O
O
ST
Digital I/O.
External memory high byte control.
VSS 11, 31, 51,
70
P Ground reference for logic and I/O pins.
VDD 32, 48, 71 P Positive supply for peripheral digital logic and I/O pins.
AVss 26 P Ground reference for analog modules.
AVDD 25 P Positive supply for analog modules.
ENVREG 24 I ST Enable for on-chip voltage regulator.
VDDCORE/VCAP
VDDCORE
VCAP
12
P
P
Core logic power or external filter capacitor connection.
Positive supply for microcontroller core logic
(regulator disabled).
External filter capacitor connection (regulator enabled).
TABLE 1-4: PIC18F8XJ1X PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type
Buffer
Type Description
80-TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
Note 1: Alternate assignment for ECCP2/P2A when Configuration bit, CCP2MX, is cleared (Extended Microcontroller mode).
2: Default assignment for ECCP2/P2A for all devices in all operating modes (CCP2MX is set).
3: Default assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is set).
4: Alternate assignment for ECCP2/P2A when CCP2MX is cleared (Microcontroller mode).
5: Alternate assignments for P1B/P1C/P3B/P3C (ECCPMX Configuration bit is cleared).
6: Default assignment for PMP data and control pins when PMPMX Configuration bit is set.
7: Alternate assignment for PMP data and control pins when PMPMX Configuration bit is cleared (programmed).
PIC18F87J11 FAMILY
DS39778C-page 30 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 31
PIC18F87J11 FAMILY
2.0 OSCILLATOR
CONFIGURATIONS
2.1 Oscillator Types
The PIC18F87J11 family of devices can be operated in
eight different oscillator modes:
1. HS High-Speed Crystal/Resonator
2. HSPLL High-Speed Crystal/Resonator
with Software PLL Control
3. EC External Clock with FOSC/4 Output
4. ECPLL External Clock with Software PLL
Control
5. INTIO1 Internal Oscillator Block with FOSC/4
Output on RA6 and I/O on RA7
6. INTIO2 Internal Oscillator Block with I/O on
RA6 and RA7
7. INTPLL1 Internal Oscillator Block with Software
PLL Control, FOSC/4 Output on RA6
and I/O on RA7
8. INTPLL2 Internal Oscillator Block with Software
PLL Control and I/O on RA6 and RA7
All of these modes are selected by the user by
programming the FOSC2:FOSC0 Configuration bits.
In addition, PIC18F87J11 Family devices can switch
between different clock sources, either under software
control or automatically under certain conditions. This
allows for additional power savings by managing
device clock speed in real time without resetting the
application.
The clock sources for the PIC18F87J11 family of
devices are shown in Figure 2-1.
FIGURE 2-1: PIC18F87J11 FAMILY CLOCK DIAGRAM
PIC18F87J11 Family
4 x PLL
FOSC2:FOSC0
Secondary Oscillator
T1OSCEN
Enable
Oscillator
T1OSO
T1OSI
Clock Source Option
for Other Modules
OSC1
OSC2
Sleep HSPLL, ECPLL, INTPLL
HS, EC
T1OSC
CPU
Peripherals
IDLEN
Postscaler
MUX
MUX
8 MHz
4 MHz
2 MHz
1 MHz
500 kHz
125 kHz
250 kHz
OSCCON<6:4>
111
110
101
100
011
010
001
000
31 kHz
INTRC
Source
Internal
Oscillator
Block
WDT, PWRT, FSCM
8 MHz
Internal Oscillator
(INTOSC)
OSCCON<6:4>
Clock
Control
OSCCON<1:0>
Source
8 MHz
31 kHz (INTRC)
0
1
OSCTUNE<7>
and Two-Speed Start-up
Primary Oscillator
OSCTUNE<6>
PIC18F87J11 FAMILY
DS39778C-page 32 Preliminary © 2008 Microchip Technology Inc.
2.2 Control Registers
The OSCCON register (Register 2-1) controls the main
aspects of the device clock’s operation. It selects the
oscillator type to be used, which of the power-managed
modes to invoke and the output frequency of the
INTOSC source. It also provides status on the oscillators.
The OSCTUNE register (Register 2-2) controls the
tuning and operation of the internal oscillator block. It
also implements the PLLEN bits which control the
operation of the Phase Locked Loop (PLL) (see
Section 2.4.3 “PLL Frequency Multiplier”).
REGISTER 2-1: OSCCON: OSCILLATOR CONTROL REGISTER(1)
R/W-0 R/W-1 R/W-1 R/W-0 R(2) U-1 R/W-0 R/W-0
IDLEN IRCF2(3) IRCF1(3) IRCF0(3) OSTS —SCS1
(5) SCS0(5)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IDLEN: Idle Enable bit
1 = Device enters an Idle mode when a SLEEP instruction is executed
0 = Device enters Sleep mode when a SLEEP instruction is executed
bit 6-4 IRCF2:IRCF0: INTOSC Source Frequency Select bits(3)
111 = 8 MHz (INTOSC drives clock directly)
110 = 4 MHz (default)
101 = 2 MHz
100 = 1 MHz
011 = 500 kHz
010 = 250 kHz
001 = 125 kHz
000 = 31 kHz (from either INTOSC/256 or INTRC)(4)
bit 3 OSTS: Oscillator Start-up Timer Time-out Status bit(2)
1 = Oscillator Start-up Timer (OST) time-out has expired; primary oscillator is running
0 = Oscillator Start-up Timer (OST) time-out is running; primary oscillator is not ready
bit 2 Unimplemented: Read as1
bit 1-0 SCS1:SCS0: System Clock Select bits(5)
11 = Internal oscillator block
10 = Primary oscillator
01 = Timer1 oscillator
00 = Default primary oscillator (as defined by FOSC2:FOSC0 Configuration bits)
Note 1: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
2: Reset state depends on state of the IESO Configuration bit.
3: Modifying these bits will cause an immediate clock frequency switch if the internal oscillator is providing
the device clocks.
4: Source selected by the INTSRC bit (OSCTUNE<7>), see text.
5: Modifying these bits will cause an immediate clock source switch.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 33
PIC18F87J11 FAMILY
2.3 Clock Sources and
Oscillator Switching
Essentially, PIC18F87J11 Family devices have three
independent clock sources:
Primary oscillators
Secondary oscillators
Internal oscillator
The primary oscillators can be thought of as the main
device oscillators. These are any external oscillators
connected to the OSC1 and OSC2 pins, and include
the External Crystal and Resonator modes and the
External Clock modes. If selected by the
FOSC2:FOSC0 Configuration bits, the internal
oscillator block (either the 31 kHz INTRC or the 8 MHz
INTOSC source) may be considered a primary
oscillator. The particular mode is defined by the FOSC
Configuration bits. The details of these modes are
covered in Section 2.4 “External Oscillator Modes”.
The secondary oscillators are external clock sources
that are not connected to the OSC1 or OSC2 pins.
These sources may continue to operate even after the
controller is placed in a power-managed mode.
PIC18F87J11 Family devices offer the Timer1 oscillator
as a secondary oscillator source. This oscillator, in all
power-managed modes, is often the time base for
functions such as a Real-Time Clock (RTC). The
Timer1 oscillator is discussed in greater detail in
Section 13.0 “Timer1 Module”
In addition to being a primary clock source in some cir-
cumstances, the internal oscillator is available as a
power-managed mode clock source. The INTRC
source is also used as the clock source for several
special features, such as the WDT and Fail-Safe Clock
Monitor. The internal oscillator block is discussed in
more detail in Section 2.5 “Internal Oscillator
Block”.
The PIC18F87J11 Family includes features that allow
the device clock source to be switched from the main
oscillator, chosen by device configuration, to one of the
alternate clock sources. When an alternate clock
source is enabled, various power-managed operating
modes are available.
REGISTER 2-2: OSCTUNE: OSCILLATOR TUNING REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
INTSRC PLLEN TUN5 TUN4 TUN3 TUN2 TUN1 TUN0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 INTSRC: Internal Oscillator Low-Frequency Source Select bit
1 = 31.25 kHz device clock derived from 8 MHz INTOSC source (divide-by-256 enabled)
0 = 31 kHz device clock derived from INTRC 31 kHz oscillator
bit 6 PLLEN: Frequency Multiplier PLL Enable bit
1 = PLL enabled
0 = PLL disabled
bit 5-0 TUN5:TUN0: Fast RC Oscillator (INTOSC) Frequency Tuning bits
011111 = Maximum frequency
000001
000000 = Center frequency. Fast RC oscillator is running at the calibrated frequency.
111111
100000 = Minimum frequency
PIC18F87J11 FAMILY
DS39778C-page 34 Preliminary © 2008 Microchip Technology Inc.
2.3.1 CLOCK SOURCE SELECTION
The System Clock Select bits, SCS1:SCS0
(OSCCON<1:0>), select the clock source. The avail-
able clock sources are the primary clock defined by the
FOSC2:FOSC0 Configuration bits, the secondary
clock (Timer1 oscillator) and the internal oscillator. The
clock source changes after one or more of the bits are
written to, following a brief clock transition interval.
The OSTS (OSCCON<3>) and T1RUN (T1CON<6>)
bits indicate which clock source is currently providing
the device clock. The OSTS bit indicates that the
Oscillator Start-up Timer (OST) has timed out and the
primary clock is providing the device clock in primary
clock modes. The T1RUN bit indicates when the
Timer1 oscillator is providing the device clock in sec-
ondary clock modes. In power-managed modes, only
one of these bits will be set at any time. If neither of
these bits is set, the INTRC is providing the clock, or
the internal oscillator has just started and is not yet
stable.
The IDLEN bit determines if the device goes into Sleep
mode or one of the Idle modes when the SLEEP
instruction is executed.
The use of the flag and control bits in the OSCCON
register is discussed in more detail in Section 3.0
“Power-Managed Modes”.
2.3.1.1 System Clock Selection and Device
Resets
Since the SCS bits are cleared on all forms of Reset,
this means the primary oscillator defined by the
FOSC2:FOSC0 Configuration bits is used as the
primary clock source on device Resets. This could
either be the internal oscillator block by itself, or one of
the other primary clock source (HS, EC, HSPLL,
ECPLL1/2 or INTPLL1/2).
In those cases when the internal oscillator block, with-
out PLL, is the default clock on Reset, the Fast RC
oscillator (INTOSC) will be used as the device clock
source. It will initially start at 4 MHz; the postscaler
selection that corresponds to the Reset value of the
IRCF2:IRCF0 bits (‘110’).
Regardless of which primary oscillator is selected,
INTRC will always be enabled on device power-up. It
serves as the clock source until the device has loaded
its configuration values from memory. It is at this point
that the FOSC Configuration bits are read and the
oscillator selection of the operational mode is made.
Note that either the primary clock source, or the internal
oscillator, will have two bit setting options for the possible
values of the SCS1:SCS0 bits at any given time.
2.3.2 OSCILLATOR TRANSITIONS
PIC18F87J11 family devices contain circuitry to
prevent clock “glitches” when switching between clock
sources. A short pause in the device clock occurs dur-
ing the clock switch. The length of this pause is the sum
of two cycles of the old clock source and three to four
cycles of the new clock source. This formula assumes
that the new clock source is stable.
Clock transitions are discussed in greater detail in
Section 3.1.2 “Entering Power-Managed Modes”.
Note 1: The Timer1 oscillator must be enabled to
select the secondary clock source. The
Timer1 oscillator is enabled by setting the
T1OSCEN bit in the Timer1 Control regis-
ter (T1CON<3>). If the Timer1 oscillator is
not enabled, then any attempt to select a
secondary clock source when executing a
SLEEP instruction will be ignored.
2: It is recommended that the Timer1
oscillator be operating and stable before
executing the SLEEP instruction or a very
long delay may occur while the Timer1
oscillator starts.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 35
PIC18F87J11 FAMILY
2.4 External Oscillator Modes
2.4.1 CRYSTAL OSCILLATOR/CERAMIC
RESONATORS (HS MODES)
In HS or HSPLL Oscillator modes, a crystal or ceramic
resonator is connected to the OSC1 and OSC2 pins to
establish oscillation. Figure 2-2 shows the pin
connections.
The oscillator design requires the use of a crystal rated
for parallel resonant operation.
TABLE 2-1: CAPACITOR SELECTION FOR
CERAMIC RESONATORS
TABLE 2-2: CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
FIGURE 2-2: CRYSTAL/CERAMIC
RESONATOR OPERATION
(HS OR HSPLL
CONFIGURATION)
Note: Use of a crystal rated for series resonant
operation may give a frequency out of the
crystal manufacturer’s specifications.
Typical Capacitor Values Used:
Mode Freq. OSC1 OSC2
HS 8.0 MHz
16.0 MHz
27 pF
22 pF
27 pF
22 pF
Capacitor values are for design guidance only.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
VDD and temperature range for the application. Refer
to the following application notes for oscillator specific
information:
AN588, “PIC® Microcontroller Oscillator Design
Guide”
AN826, “Crystal Oscillator Basics and Crystal
Selection for rfPIC® and PIC® Devices”
AN849, “Basic PIC® Oscillator Design
AN943, “Practical PIC® Oscillator Analysis and
Design”
AN949, “Making Your Oscillator Work”
See the notes following Table 2-2 for additional
information.
Osc Type Crystal
Freq.
Typical Capacitor Values
Tested:
C1 C2
HS 4 MHz 27 pF 27 pF
8 MHz 22 pF 22 pF
20 MHz 15 pF 15 pF
Capacitor values are for design guidance only.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
VDD and temperature range for the application.
Refer to the Microchip application notes cited in
Table 2-1 for oscillator specific information. Also see
the notes following this table for additional
information.
Note 1: Higher capacitance increases the stability
of oscillator but also increases the start-up
time.
2: Since each resonator/crystal has its own
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate values of external
components.
3: Rs may be required to avoid overdriving
crystals with low drive level specification.
4: Always verify oscillator performance over
the VDD and temperature range that is
expected for the application.
Note 1: See Table 2-1 and Table 2-2 for initial values of
C1 and C2.
2: A series resistor (RS) may be required for AT
strip cut crystals.
3: RF varies with the oscillator mode chosen.
C1(1)
C2(1)
XTAL
OSC2
OSC1
RF(3)
Sleep
To
Logic
PIC18F87J11
RS(2)
Internal
PIC18F87J11 FAMILY
DS39778C-page 36 Preliminary © 2008 Microchip Technology Inc.
2.4.2 EXTERNAL CLOCK INPUT
(EC MODES)
The EC and ECPLL Oscillator modes require an
external clock source to be connected to the OSC1 pin.
There is no oscillator start-up time required after a
Power-on Reset or after an exit from Sleep mode.
In the EC Oscillator mode, the oscillator frequency
divided by 4 is available on the OSC2 pin. This signal
may be used for test purposes or to synchronize other
logic. Figure 2-3 shows the pin connections for the EC
Oscillator mode.
FIGURE 2-3: EXTERNAL CLOCK
INPUT OPERATION
(EC CONFIGURATION)
An external clock source may also be connected to the
OSC1 pin in the HS mode, as shown in Figure 2-4. In
this configuration, the divide-by-4 output on OSC2 is
not available. Current consumption in this configuration
will be somewhat higher than EC mode, as the internal
oscillator’s feedback circuitry will be enabled (in EC
mode, the feedback circuit is disabled).
FIGURE 2-4: EXTERNAL CLOCK INPUT
OPERATION (HS OSC
CONFIGURATION)
2.4.3 PLL FREQUENCY MULTIPLIER
A Phase Locked Loop (PLL) circuit is provided as an
option for users who want to use a lower frequency
oscillator circuit, or to clock the device up to its highest
rated frequency from a crystal oscillator. This may be
useful for customers who are concerned with EMI due
to high-frequency crystals, or users who require higher
clock speeds from an internal oscillator.
2.4.3.1 HSPLL and ECPLL Modes
The HSPLL and ECPLL modes provide the ability to
selectively run the device at 4 times the external
oscillating source to produce frequencies up to
40 MHz.
The PLL is enabled by programming the
FOSC2:FOSC0 Configuration bits to either ‘111’ (for
ECPLL) or ‘101’ (for HSPLL). In addition, the PLLEN bit
(OSCTUNE<6>) must also be set. Clearing PLLEN
disables the PLL, regardless of the chosen oscillator
configuration. It also allows additional flexibility for
controlling the application’s clock speed in software.
FIGURE 2-5: PLL BLOCK DIAGRAM
2.4.3.2 PLL and INTOSC
The PLL is also available to the internal oscillator block
when the internal oscillator block is configured as the
primary clock source. In this configuration, the PLL is
enabled in software and generates a clock output of up
to 32 MHz. The operation of INTOSC with the PLL is
described in Section 2.5.2 “INTPLL Modes”.
OSC1/CLKI
OSC2/CLKO
FOSC/4
Clock from
Ext. System PIC18F87J11
OSC1
OSC2
Open
Clock from
Ext. System PIC18F87J11
(HS Mode)
MUX
VCO
Loop
Filter
OSC2
OSC1
PLL Enable (OSCTUNE)
FIN
FOUT
SYSCLK
Phase
Comparator
HSPLL or ECPLL (CONFIG2L)
÷4
HS or EC
Mode
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 37
PIC18F87J11 FAMILY
2.5 Internal Oscillator Block
The PIC18F87J11 Family of devices includes an
internal oscillator block which generates two different
clock signals; either can be used as the microcontrol-
ler’s clock source. This may eliminate the need for an
external oscillator circuit on the OSC1 and/or OSC2
pins.
The main output is the Fast RC oscillator, or INTOSC,
an 8 MHz clock source which can be used to directly
drive the device clock. It also drives a postscaler, which
can provide a range of clock frequencies from 31 kHz
to 4 MHz. INTOSC is enabled when a clock frequency
from 125 kHz to 8 MHz is selected. The INTOSC out-
put can also be enabled when 31 kHz is selected,
depending on the INTSRC bit (OSCTUNE<7>).
The other clock source is the internal RC oscillator
(INTRC), which provides a nominal 31 kHz output.
INTRC is enabled if it is selected as the device clock
source; it is also enabled automatically when any of the
following are enabled:
Power-up Timer
Fail-Safe Clock Monitor
Watchdog Timer
Two-Speed Start-up
These features are discussed in greater detail in
Section 24.0 “Special Features of the CPU”.
The clock source frequency (INTOSC direct, INTOSC
with postscaler or INTRC direct) is selected by config-
uring the IRCF bits of the OSCCON register. The
default frequency on device Resets is 4 MHz.
2.5.1 INTIO MODES
Using the internal oscillator as the clock source elimi-
nates the need for up to two external oscillator pins,
which can then be used for digital I/O. Two distinct
oscillator configurations, which are determined by the
FOSC Configuration bits, are available:
In INTIO1 mode, the OSC2 pin outputs FOSC/4,
while OSC1 functions as RA7 (see Figure 2-6) for
digital input and output.
In INTIO2 mode, OSC1 functions as RA7 and
OSC2 functions as RA6 (see Figure 2-7), both for
digital input and output.
FIGURE 2-6: INTIO1 OSCILLATOR MODE
FIGURE 2-7: INTIO2 OSCILLATOR MODE
2.5.2 INTPLL MODES
The 4x Phase Locked Loop (PLL) can be used with the
internal oscillator block to produce faster device clock
speeds than are normally possible with the internal
oscillator sources. When enabled, the PLL produces a
clock speed of 16 MHz or 32 MHz.
PLL operation is controlled through software. The con-
trol bit, PLLEN (OSCTUNE<6>), is used to enable or
disable its operation. The PLL is available only to
INTOSC when the device is configured to use one of
the INTPLL modes as the primary clock source
(FOSC2:FOSC0 = 011 or 010). Additionally, the PLL
will only function when the selected output frequency is
either 4 MHz or 8 MHz (OSCCON<6:4> = 111 or 110).
Like the INTIO modes, there are two distinct INTPLL
modes available:
In INTPLL1 mode, the OSC2 pin outputs FOSC/4,
while OSC1 functions as RA7 for digital input and
output. Externally, this is identical in appearance
to INTIO1 (Figure 2-6).
In INTPLL2 mode, OSC1 functions as RA7 and
OSC2 functions as RA6, both for digital input and
output. Externally, this is identical to INTIO2
(Figure 2-7).
PIC18F87J11
OSC2
FOSC/4
I/O (OSC1)
RA7
PIC18F87J11
I/O (OSC2)
RA6
I/O (OSC1)
RA7
PIC18F87J11 FAMILY
DS39778C-page 38 Preliminary © 2008 Microchip Technology Inc.
2.5.3 INTERNAL OSCILLATOR OUTPUT
FREQUENCY AND TUNING
The internal oscillator block is calibrated at the factory
to produce an INTOSC output frequency of 8 MHz. It
can be adjusted in the user’s application by writing to
TUN5:TUN0 (OSCTUNE<5:0>) in the OSCTUNE
register (Register 2-2).
When the OSCTUNE register is modified, the INTOSC
frequency will begin shifting to the new frequency. The
oscillator will stabilize within 1 ms. Code execution
continues during this shift and there is no indication that
the shift has occurred.
The INTRC oscillator operates independently of the
INTOSC source. Any changes in INTOSC across
voltage and temperature are not necessarily reflected
by changes in INTRC or vice versa. The frequency of
INTRC is not affected by OSCTUNE.
2.5.4 INTOSC FREQUENCY DRIFT
The INTOSC frequency may drift as VDD or tempera-
ture changes, and can affect the controller operation in
a variety of ways. It is possible to adjust the INTOSC
frequency by modifying the value in the OSCTUNE reg-
ister. Depending on the device, this may have no effect
on the INTRC clock source frequency.
Tuning INTOSC requires knowing when to make the
adjustment, in which direction it should be made, and in
some cases, how large a change is needed. Three
compensation techniques are shown here.
2.5.4.1 Compensating with the EUSART
An adjustment may be required when the EUSART
begins to generate framing errors or receives data with
errors while in Asynchronous mode. Framing errors
indicate that the device clock frequency is too high. To
adjust for this, decrement the value in OSCTUNE to
reduce the clock frequency. On the other hand, errors
in data may suggest that the clock speed is too low. To
compensate, increment OSCTUNE to increase the
clock frequency.
2.5.4.2 Compensating with the Timers
This technique compares device clock speed to some
reference clock. Two timers may be used; one timer is
clocked by the peripheral clock, while the other is
clocked by a fixed reference source, such as the
Timer1 oscillator.
Both timers are cleared, but the timer clocked by the
reference generates interrupts. When an interrupt
occurs, the internally clocked timer is read and both
timers are cleared. If the internally clocked timer value
is much greater than expected, then the internal
oscillator block is running too fast. To adjust for this,
decrement the OSCTUNE register.
2.5.4.3 Compensating with the CCP Module
in Capture Mode
A CCP module can use free-running Timer1 (or
Timer3), clocked by the internal oscillator block and an
external event with a known period (i.e., AC power
frequency). The time of the first event is captured in the
CCPRxH:CCPRxL registers and is recorded for use
later. When the second event causes a capture, the
time of the first event is subtracted from the time of the
second event. Since the period of the external event is
known, the time difference between events can be
calculated.
If the measured time is much greater than the
calculated time, the internal oscillator block is running
too fast. To compensate, decrement the OSCTUNE
register. If the measured time is much less than the
calculated time, the internal oscillator block is running
too slow. To compensate, increment the OSCTUNE
register.
2.6 Reference Clock Output
In addition to the FOSC/4 clock output in certain oscilla-
tor modes, the device clock in the PIC18F87J11 family
can also be configured to provide a reference clock out-
put signal to a port pin. This feature is available in all
oscillator configurations and allows the user to select a
greater range of clock sub-multiples to drive external
devices in the application.
This reference clock output is controlled by the
REFOCON register (Register 2-3). Setting the ROON
bit (REFOCON<7>) makes the clock signal available
on the REFO (RE3) pin. The RODIV3:RODIV0 bits
enable the selection of 16 different clock divider
options.
The ROSSLP and ROSEL bits (REFOCON<5:4>) con-
trol the availability of the reference output during Sleep
mode. The ROSEL bit determines if the oscillator on
OSC1 and OSC2, or the current system clock source,
is used for the reference clock output. The ROSSLP bit
determines if the reference source is available on RE3
when the device is in Sleep mode.
To use the reference clock output in Sleep mode, both
the ROSSLP and ROSEL bits must be set. The device
clock must also be configured for an EC or HS mode;
otherwise, the oscillator on OSC1 and OSC2 will be
powered down when the device enters Sleep mode.
Clearing the ROSEL bit allows the reference output
frequency to change as the system clock changes
during any clock switches.
The REFOCON register is an alternate SFR, and
shares the same memory address as the OSCCON
register. It is accessed by setting the ADSHR bit in the
WDTCON register (WDTCON<4>).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 39
PIC18F87J11 FAMILY
REGISTER 2-3: REFOCON: REFERENCE OSCILLATOR CONTROL REGISTER
R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ROON ROSSLP ROSEL(1) RODIV3 RODIV2 RODIV1 RODIV0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 ROON: Reference Oscillator Output Enable bit
1 = Reference oscillator output available on REFO pin
0 = Reference oscillator output disabled
bit 6 Unimplemented: Read as ‘0
bit 5 ROSSLP: Reference Oscillator Output Stop in Sleep bit
1 = Reference oscillator continues to run in Sleep
0 = Reference oscillator is disabled in Sleep
bit 4 ROSEL: Reference Oscillator Source Select bit(1)
1 = Primary oscillator (EC or HS) used as the base clock
0 = System clock used as the base clock; base clock reflects any clock switching of the device
bit 3-0 RODIV3:RODIV0: Reference Oscillator Divisor Select bits
1111 = Base clock value divided by 32,768
1110 = Base clock value divided by 16,384
1101 = Base clock value divided by 8,192
1100 = Base clock value divided by 4,096
1011 = Base clock value divided by 2,048
1010 = Base clock value divided by 1,024
1001 = Base clock value divided by 512
1000 = Base clock value divided by 256
0111 = Base clock value divided by 128
0110 = Base clock value divided by 64
0101 = Base clock value divided by 32
0100 = Base clock value divided by 16
0011 = Base clock value divided by 8
0010 = Base clock value divided by 4
0001 = Base clock value divided by 2
0000 = Base clock value
Note 1: If ROSEL = 1, an EC or HS oscillator must be configured as the default oscillator with the FOSC Configuration
bits to maintain clock output during Sleep mode.
PIC18F87J11 FAMILY
DS39778C-page 40 Preliminary © 2008 Microchip Technology Inc.
2.7 Effects of Power-Managed Modes
on the Various Clock Sources
When PRI_IDLE mode is selected, the designated pri-
mary oscillator continues to run without interruption.
For all other power-managed modes, the oscillator
using the OSC1 pin is disabled. The OSC1 pin (and
OSC2 pin if used by the oscillator) will stop oscillating.
In secondary clock modes (SEC_RUN and
SEC_IDLE), the Timer1 oscillator is operating and
providing the device clock. The Timer1 oscillator may
also run in all power-managed modes if required to
clock Timer1 or Timer3.
In RC_RUN and RC_IDLE modes, the internal
oscillator provides the device clock source. The 31 kHz
INTRC output can be used directly to provide the clock
and may be enabled to support various special
features, regardless of the power-managed mode (see
Section 24.2 “Watchdog Timer (WDT) through
Section 24.5 “Fail-Safe Clock Monitor for more
information on WDT, Fail-Safe Clock Monitor and
Two-Speed Start-up).
If the Sleep mode is selected, all clock sources are
stopped. Since all the transistor switching currents
have been stopped, Sleep mode achieves the lowest
current consumption of the device (only leakage
currents).
Enabling any on-chip feature that will operate during
Sleep will increase the current consumed during Sleep.
The INTRC is required to support WDT operation. The
Timer1 oscillator may be operating to support a Real-
Time Clock (RTC). Other features may be operating
that do not require a device clock source (i.e., MSSP
slave, PSP, INTx pins and others). Peripherals that
may add significant current consumption are listed in
Section 27.2 “DC Characteristics: Power-Down and
Supply Current”.
2.8 Power-up Delays
Power-up delays are controlled by two timers, so that
no external Reset circuitry is required for most applica-
tions. The delays ensure that the device is kept in
Reset until the device power supply is stable under nor-
mal circumstances and the primary clock is operating
and stable. For additional information on power-up
delays, see Section 4.6 “Power-up Timer (PWRT)”.
The first timer is the Power-up Timer (PWRT), which
provides a fixed delay on power-up (parameter 33,
Table 27-12); it is always enabled.
The second timer is the Oscillator Start-up Timer
(OST), intended to keep the chip in Reset until the
crystal oscillator is stable (HS modes). The OST does
this by counting 1024 oscillator cycles before allowing
the oscillator to clock the device.
There is a delay of interval T
CSD (parameter 38,
Table 27-12), following POR, while the controller
becomes ready to execute instructions.
TABLE 2-3: OSC1 AND OSC2 PIN STATES IN SLEEP MODE
Oscillator Mode OSC1 Pin OSC2 Pin
EC, ECPLL Floating, pulled by external clock At logic low (clock/4 output)
HS, HSPLL Feedback inverter disabled at quiescent
voltage level
Feedback inverter disabled at quiescent
voltage level
INTOSC, INTPLL1/2 I/O pin RA6, direction controlled by
TRISA<6>
I/O pin RA6, direction controlled by
TRISA<7>
Note: See Section 4.0 “Reset” for time-outs due to Sleep and MCLR Reset.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 41
PIC18F87J11 FAMILY
3.0 POWER-MANAGED MODES
The PIC18F87J11 Family of devices provides the ability
to manage power consumption by simply managing
clocking to the CPU and the peripherals. In general, a
lower clock frequency and a reduction in the number of
circuits being clocked constitutes lower consumed
power. For the sake of managing power in an
application, there are three primary modes of operation:
Run mode
Idle mode
Sleep mode
These modes define which portions of the device are
clocked and at what speed. The Run and Idle modes
may use any of the three available clock sources (pri-
mary, secondary or internal oscillator block); the Sleep
mode does not use a clock source.
The power-managed modes include several
power-saving features offered on previous devices.
One is the clock switching feature, offered in other
PIC18 devices, allowing the controller to use the
Timer1 oscillator in place of the primary oscillator. Also
included is the Sleep mode, offered by all PIC®
devices, where all device clocks are stopped.
3.1 Selecting Power-Managed Modes
Selecting a power-managed mode requires two
decisions: if the CPU is to be clocked or not and which
clock source is to be used. The IDLEN bit
(OSCCON<7>) controls CPU clocking, while the
SCS1:SCS0 bits (OSCCON<1:0>) select the clock
source. The individual modes, bit settings, clock
sources and affected modules are summarized in
Table 3-1.
3.1.1 CLOCK SOURCES
The SCS1:SCS0 bits allow the selection of one of three
clock sources for power-managed modes. They are:
the primary clock, as defined by the
FOSC2:FOSC0 Configuration bits
the secondary clock (Timer1 oscillator)
the internal oscillator
3.1.2 ENTERING POWER-MANAGED
MODES
Switching from one power-managed mode to another
begins by loading the OSCCON register. The
SCS1:SCS0 bits select the clock source and determine
which Run or Idle mode is to be used. Changing these
bits causes an immediate switch to the new clock
source, assuming that it is running. The switch may
also be subject to clock transition delays. These are
discussed in Section 3.1.3 “Clock Transitions and
Status Indicators” and subsequent sections.
Entry to the power-managed Idle or Sleep modes is
triggered by the execution of a SLEEP instruction. The
actual mode that results depends on the status of the
IDLEN bit.
Depending on the current mode and the mode being
switched to, a change to a power-managed mode does
not always require setting all of these bits. Many
transitions may be done by changing the oscillator
select bits, or changing the IDLEN bit, prior to issuing a
SLEEP instruction. If the IDLEN bit is already
configured correctly, it may only be necessary to
perform a SLEEP instruction to switch to the desired
mode.
TABLE 3-1: POWER-MANAGED MODES
Mode
OSCCON<7,1:0> Module Clocking
Available Clock and Oscillator Source
IDLEN(1) SCS1:SCS0 CPU Peripherals
Sleep 0N/A Off Off None – All clocks are disabled
PRI_RUN N/A 10 Clocked Clocked Primary – HS, EC, HSPLL, ECPLL, INTOSC
oscillator;
this is the normal, full-power execution mode
SEC_RUN N/A 01 Clocked Clocked Secondary – Timer1 oscillator
RC_RUN N/A 11 Clocked Clocked Internal oscillator block(2)
PRI_IDLE 110Off Clocked Primary HS, EC, HSPLL, ECPLL, INTOSC
SEC_IDLE 101Off Clocked Secondary – Timer1 oscillator
RC_IDLE 111Off Clocked Internal oscillator block(2)
Note 1: IDLEN reflects its value when the SLEEP instruction is executed.
2: Includes INTRC and INTOSC postcaler (internal oscillator block).
PIC18F87J11 FAMILY
DS39778C-page 42 Preliminary © 2008 Microchip Technology Inc.
3.1.3 CLOCK TRANSITIONS AND STATUS
INDICATORS
The length of the transition between clock sources is
the sum of two cycles of the old clock source and three
to four cycles of the new clock source. This formula
assumes that the new clock source is stable.
Two bits indicate the current clock source and its status:
OSTS (OSCCON<3>) and T1RUN (T1CON<6>). In
general, only one of these bits will be set while in a given
power-managed mode. When the OSTS bit is set, the
primary clock is providing the device clock. When the
T1RUN bit is set, the Timer1 oscillator is providing the
clock. If neither of these bits is set, INTRC is clocking the
device.
3.1.4 MULTIPLE SLEEP COMMANDS
The power-managed mode that is invoked with the
SLEEP instruction is determined by the setting of the
IDLEN bit at the time the instruction is executed. If
another SLEEP instruction is executed, the device will
enter the power-managed mode specified by IDLEN at
that time. If IDLEN has changed, the device will enter
the new power-managed mode specified by the new
setting.
3.2 Run Modes
In the Run modes, clocks to both the core and
peripherals are active. The difference between these
modes is the clock source.
3.2.1 PRI_RUN MODE
The PRI_RUN mode is the normal, full-power execu-
tion mode of the microcontroller. This is also the default
mode upon a device Reset unless Two-Speed Start-up
is enabled (see Section 24.4 “Two-Speed Start-up”
for details). In this mode, the OSTS bit is set. (see
Section 2.2 “Control Registers”).
3.2.2 SEC_RUN MODE
The SEC_RUN mode is the compatible mode to the
“clock switching” feature offered in other PIC18
devices. In this mode, the CPU and peripherals are
clocked from the Timer1 oscillator. This gives users the
option of lower power consumption while still using a
high-accuracy clock source.
SEC_RUN mode is entered by setting the SCS1:SCS0
bits to ‘01’. The device clock source is switched to the
Timer1 oscillator (see Figure 3-1), the primary oscilla-
tor is shut down, the T1RUN bit (T1CON<6>) is set and
the OSTS bit is cleared.
Note: Executing a SLEEP instruction does not
necessarily place the device into Sleep
mode. It acts as the trigger to place the
controller into either the Sleep mode, or
one of the Idle modes, depending on the
setting of the IDLEN bit.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 43
PIC18F87J11 FAMILY
On transitions from SEC_RUN mode to PRI_RUN
mode, the peripherals and CPU continue to be clocked
from the Timer1 oscillator while the primary clock is
started. When the primary clock becomes ready, a
clock switch back to the primary clock occurs (see
Figure 3-2). When the clock switch is complete, the
T1RUN bit is cleared, the OSTS bit is set and the
primary clock is providing the clock. The IDLEN and
SCS bits are not affected by the wake-up; the Timer1
oscillator continues to run.
FIGURE 3-1: TRANSITION TIMING FOR ENTRY TO SEC_RUN MODE
FIGURE 3-2: TRANSITION TIMING FROM SEC_RUN MODE TO PRI_RUN MODE (HSPLL)
Note: The Timer1 oscillator should already be
running prior to entering SEC_RUN mode.
If the T1OSCEN bit is not set when the
SCS1:SCS0 bits are set to ‘01’, entry to
SEC_RUN mode will not occur. If the
Timer1 oscillator is enabled, but not yet
running, device clocks will be delayed until
the oscillator has started. In such situa-
tions, initial oscillator operation is far from
stable and unpredictable operation may
result.
Q4Q3Q2
OSC1
Peripheral
Program
Q1
T1OSI
Q1
Counter
Clock
CPU
Clock
PC + 2PC
123
n-1
n
Clock Transition
Q4Q3Q2 Q1 Q3Q2
PC + 4
Q1 Q3 Q4
OSC1
Peripheral
Program PC
T1OSI
PLL Clock
Q1
PC + 4
Q2
Output
Q3 Q4 Q1
CPU Clock
PC + 2
Clock
Counter
Q2 Q2 Q3
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
SCS1:SCS0 Bits Changed
TPLL(1)
12 n-1n
Clock
OSTS Bit Set
Transition
TOST(1)
PIC18F87J11 FAMILY
DS39778C-page 44 Preliminary © 2008 Microchip Technology Inc.
3.2.3 RC_RUN MODE
In RC_RUN mode, the CPU and peripherals are
clocked from the internal oscillator; the primary clock is
shut down. This mode provides the best power conser-
vation of all the Run modes while still executing code.
It works well for user applications which are not highly
timing sensitive or do not require high-speed clocks at
all times.
This mode is entered by setting SCS<1:0> to ‘11’.
When the clock source is switched to the internal
oscillator block (see Figure 3-3), the primary oscillator
is shut down and the OSTS bit is cleared.
On transitions from RC_RUN mode to PRI_RUN mode,
the device continues to be clocked from the INTOSC
block while the primary clock is started. When the
primary clock becomes ready, a clock switch to the pri-
mary clock occurs (see Figure 3-4). When the clock
switch is complete, the OSTS bit is set and the primary
clock is providing the device clock. The IDLEN and
SCS bits are not affected by the switch. The INTRC
block source will continue to run if either the WDT or the
Fail-Safe Clock Monitor is enabled.
FIGURE 3-3: TRANSITION TIMING TO RC_RUN MODE
FIGURE 3-4: TRANSITION TIMING FROM RC_RUN MODE TO PRI_RUN MODE
Q4Q3Q2
OSC1
Peripheral
Program
Q1
INTRC
Q1
Counter
Clock
CPU
Clock
PC + 2PC
123 n-1n
Clock Transition
Q4Q3Q2 Q1 Q3Q2
PC + 4
Q1 Q3 Q4
OSC1
Peripheral
Program PC
INTRC
PLL Clock
Q1
PC + 4
Q2
Output
Q3 Q4 Q1
CPU Clock
PC + 2
Clock
Counter
Q2 Q2 Q3
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
SCS1:SCS0 Bits Changed
TPLL(1)
12 n-1n
Clock
OSTS Bit Set
Transition
TOST(1)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 45
PIC18F87J11 FAMILY
3.3 Sleep Mode
The power-managed Sleep mode is identical to the leg-
acy Sleep mode offered in all other PIC devices. It is
entered by clearing the IDLEN bit (the default state on
device Reset) and executing the SLEEP instruction.
This shuts down the selected oscillator (Figure 3-5). All
clock source status bits are cleared.
Entering the Sleep mode from any other mode does not
require a clock switch. This is because no clocks are
needed once the controller has entered Sleep. If the
WDT is selected, the INTRC source will continue to
operate. If the Timer1 oscillator is enabled, it will also
continue to run.
When a wake event occurs in Sleep mode (by interrupt,
Reset or WDT time-out), the device will not be clocked
until the clock source selected by the SCS1:SCS0 bits
becomes ready (see Figure 3-6), or it will be clocked
from the internal oscillator if either the Two-Speed
Start-up or the Fail-Safe Clock Monitor are enabled
(see Section 24.0 “Special Features of the CPU). In
either case, the OSTS bit is set when the primary clock
is providing the device clocks. The IDLEN and SCS bits
are not affected by the wake-up.
3.4 Idle Modes
The Idle modes allow the controller’s CPU to be
selectively shut down while the peripherals continue to
operate. Selecting a particular Idle mode allows users
to further manage power consumption.
If the IDLEN bit is set to ‘1’ when a SLEEP instruction is
executed, the peripherals will be clocked from the clock
source selected using the SCS1:SCS0 bits; however, the
CPU will not be clocked. The clock source status bits are
not affected. Setting IDLEN and executing a SLEEP
instruction provides a quick method of switching from a
given Run mode to its corresponding Idle mode.
If the WDT is selected, the INTRC source will continue
to operate. If the Timer1 oscillator is enabled, it will also
continue to run.
Since the CPU is not executing instructions, the only
exits from any of the Idle modes are by interrupt, WDT
time-out or a Reset. When a wake event occurs, CPU
execution is delayed by an interval of TCSD
(parameter 38, Table 27-12) while it becomes ready to
execute code. When the CPU begins executing code,
it resumes with the same clock source for the current
Idle mode. For example, when waking from RC_IDLE
mode, the internal oscillator block will clock the CPU
and peripherals (in other words, RC_RUN mode). The
IDLEN and SCS bits are not affected by the wake-up.
While in any Idle mode or the Sleep mode, a WDT
time-out will result in a WDT wake-up to the Run mode
currently specified by the SCS1:SCS0 bits.
FIGURE 3-5: TRANSITION TIMING FOR ENTRY TO SLEEP MODE
FIGURE 3-6: TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL)
Q4Q3Q2
OSC1
Peripheral
Sleep
Program
Q1Q1
Counter
Clock
CPU
Clock
PC + 2
PC
Q3 Q4 Q1 Q2
OSC1
Peripheral
Program PC
PLL Clock
Q3 Q4
Output
CPU Clock
Q1 Q2 Q3 Q4 Q1 Q2
Clock
Counter PC + 6PC + 4
Q1 Q2 Q3 Q4
Wake Event
Note1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
TOST(1) TPLL(1)
OSTS Bit Set
PC + 2
PIC18F87J11 FAMILY
DS39778C-page 46 Preliminary © 2008 Microchip Technology Inc.
3.4.1 PRI_IDLE MODE
This mode is unique among the three low-power Idle
modes, in that it does not disable the primary device
clock. For timing sensitive applications, this allows for
the fastest resumption of device operation with its more
accurate primary clock source, since the clock source
does not have to “warm up” or transition from another
oscillator.
PRI_IDLE mode is entered from PRI_RUN mode by
setting the IDLEN bit and executing a SLEEP instruc-
tion. If the device is in another Run mode, set IDLEN
first, then set the SCS bits to ‘10’ and execute SLEEP.
Although the CPU is disabled, the peripherals continue
to be clocked from the primary clock source specified
by the FOSC1:FOSC0 Configuration bits. The OSTS
bit remains set (see Figure 3-7).
When a wake event occurs, the CPU is clocked from the
primary clock source. A delay of interval TCSD is
required between the wake event and when code exe-
cution starts. This is required to allow the CPU to
become ready to execute instructions. After the
wake-up, the OSTS bit remains set. The IDLEN and
SCS bits are not affected by the wake-up (see
Figure 3-8).
3.4.2 SEC_IDLE MODE
In SEC_IDLE mode, the CPU is disabled but the
peripherals continue to be clocked from the Timer1
oscillator. This mode is entered from SEC_RUN by set-
ting the IDLEN bit and executing a SLEEP instruction. If
the device is in another Run mode, set IDLEN first, then
set SCS1:SCS0 to ‘01’ and execute SLEEP. When the
clock source is switched to the Timer1 oscillator, the
primary oscillator is shut down, the OSTS bit is cleared
and the T1RUN bit is set.
When a wake event occurs, the peripherals continue to
be clocked from the Timer1 oscillator. After an interval
of TCSD following the wake event, the CPU begins exe-
cuting code being clocked by the Timer1 oscillator. The
IDLEN and SCS bits are not affected by the wake-up;
the Timer1 oscillator continues to run (see Figure 3-8).
FIGURE 3-7: TRANSITION TIMING FOR ENTRY TO IDLE MODE
FIGURE 3-8: TRANSITION TIMING FOR WAKE FROM IDLE TO RUN MODE
Note: The Timer1 oscillator should already be
running prior to entering SEC_IDLE mode.
If the T1OSCEN bit is not set when the
SLEEP instruction is executed, the SLEEP
instruction will be ignored and entry to
SEC_IDLE mode will not occur. If the
Timer1 oscillator is enabled, but not yet
running, peripheral clocks will be delayed
until the oscillator has started. In such
situations, initial oscillator operation is far
from stable and unpredictable operation
may result.
Q1
Peripheral
Program PC PC + 2
OSC1
Q3 Q4 Q1
CPU Clock
Clock
Counter
Q2
OSC1
Peripheral
Program PC
CPU Clock
Q1 Q3 Q4
Clock
Counter
Q2
Wake Event
TCSD
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 47
PIC18F87J11 FAMILY
3.4.3 RC_IDLE MODE
In RC_IDLE mode, the CPU is disabled but the
peripherals continue to be clocked from the internal
oscillator block. This mode allows for controllable
power conservation during Idle periods.
From RC_RUN, this mode is entered by setting the
IDLEN bit and executing a SLEEP instruction. If the
device is in another Run mode, first set IDLEN, then
clear the SCS bits and execute SLEEP. When the clock
source is switched to the INTOSC block, the primary
oscillator is shut down and the OSTS bit is cleared.
When a wake event occurs, the peripherals continue to
be clocked from the internal oscillator block. After a
delay of TCSD following the wake event, the CPU
begins executing code being clocked by the INTRC.
The IDLEN and SCS bits are not affected by the
wake-up. The INTRC source will continue to run if
either the WDT or the Fail-Safe Clock Monitor is
enabled.
3.5 Exiting Idle and Sleep Modes
An exit from Sleep mode, or any of the Idle modes, is
triggered by an interrupt, a Reset or a WDT time-out.
This section discusses the triggers that cause exits
from power-managed modes. The clocking subsystem
actions are discussed in each of the power-managed
modes sections (see Section 3.2 “Run Modes”,
Section 3.3 “Sleep Mode” and Section 3.4 “Idle
Modes”).
3.5.1 EXIT BY INTERRUPT
Any of the available interrupt sources can cause the
device to exit from an Idle mode, or the Sleep mode, to
a Run mode. To enable this functionality, an interrupt
source must be enabled by setting its enable bit in one
of the INTCON or PIE registers. The exit sequence is
initiated when the corresponding interrupt flag bit is set.
On all exits from Idle or Sleep modes by interrupt, code
execution branches to the interrupt vector if the
GIE/GIEH bit (INTCON<7>) is set. Otherwise, code
execution continues or resumes without branching
(see Section 9.0 “Interrupts”).
A fixed delay of interval, TCSD, following the wake event
is required when leaving Sleep and Idle modes. This
delay is required for the CPU to prepare for execution.
Instruction execution resumes on the first clock cycle
following this delay.
3.5.2 EXIT BY WDT TIME-OUT
A WDT time-out will cause different actions depending
on which power-managed mode the device is in when
the time-out occurs.
If the device is not executing code (all Idle modes and
Sleep mode), the time-out will result in an exit from the
power-managed mode (see Section 3.2 “Run
Modes” and Section 3.3 “Sleep Mode). If the device
is executing code (all Run modes), the time-out will
result in a WDT Reset (see Section 24.2 “Watchdog
Timer (WDT)”).
The Watchdog Timer and postscaler are cleared by one
of the following events:
Executing a SLEEP or CLRWDT instruction
The loss of a currently selected clock source (if
the Fail-Safe Clock Monitor is enabled)
3.5.3 EXIT BY RESET
Exiting an Idle or Sleep mode by Reset automatically
forces the device to run from the INTRC.
3.5.4 EXIT WITHOUT AN OSCILLATOR
START-UP DELAY
Certain exits from power-managed modes do not
invoke the OST at all. There are two cases:
PRI_IDLE mode, where the primary clock source
is not stopped; and
The primary clock source is either the EC or
ECPLL mode.
In these instances, the primary clock source either
does not require an oscillator start-up delay, since it is
already running (PRI_IDLE), or normally does not
require an oscillator start-up delay (EC). However, a
fixed delay of interval, T
CSD, following the wake event
is still required when leaving Sleep and Idle modes to
allow the CPU to prepare for execution. Instruction
execution resumes on the first clock cycle following this
delay.
PIC18F87J11 FAMILY
DS39778C-page 48 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 49
PIC18F87J11 FAMILY
4.0 RESET
The PIC18F87J11 Family of devices differentiate
between various kinds of Reset:
a) Power-on Reset (POR)
b) MCLR Reset during normal operation
c) MCLR Reset during power-managed modes
d) Watchdog Timer (WDT) Reset (during
execution)
e) Configuration Mismatch (CM)
f) Brown-out Reset (BOR)
g) RESET Instruction
h) Stack Full Reset
i) Stack Underflow Reset
This section discusses Resets generated by MCLR,
POR and BOR and covers the operation of the various
start-up timers. Stack Reset events are covered in
Section 5.1.6.4 “Stack Full and Underflow Resets”.
WDT Resets are covered in Section 24.2 “Watchdog
Timer (WDT)”.
A simplified block diagram of the on-chip Reset circuit
is shown in Figure 4-1.
4.1 RCON Register
Device Reset events are tracked through the RCON
register (Register 4-1). The lower five bits of the
register indicate that a specific Reset event has
occurred. In most cases, these bits can only be set by
the event and must be cleared by the application after
the event. The state of these flag bits, taken together,
can be read to indicate the type of Reset that just
occurred. This is described in more detail in
Section 4.7 “Reset State of Registers”.
The RCON register also has a control bit for setting
interrupt priority (IPEN). Interrupt priority is discussed
in Section 9.0 “Interrupts”.
FIGURE 4-1: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
External Reset
MCLR
VDD
WDT
Time-out
VDD Rise
Detect
PWRT
INTRC
POR Pulse
Chip_Reset
Brown-out
Reset(1)
RESET Instruction
Stack
Pointer
Stack Full/Underflow Reset
Sleep
( )_IDLE
32 μs
Note 1: The ENVREG pin must be tied high to enable Brown-out Reset. The Brown-out Reset is provided by the on-chip
voltage regulator when there is insufficient source voltage to maintain regulation.
PWRT
11-Bit Ripple Counter
66 ms
S
RQ
Configuration Word Mismatch
PIC18F87J11 FAMILY
DS39778C-page 50 Preliminary © 2008 Microchip Technology Inc.
REGISTER 4-1: RCON: RESET CONTROL REGISTER
R/W-0 U-0 R/W-1 R/W-1 R-1 R-1 R/W-0 R/W-0
IPEN —CMRI TO PD POR BOR
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IPEN: Interrupt Priority Enable bit
1 = Enable priority levels on interrupts
0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode)
bit 6 Unimplemented: Read as ‘0
bit 5 CM: Configuration Mismatch Flag bit
1 = A Configuration Mismatch Reset has not occurred
0 = A Configuration Mismatch Reset has occurred (must be set in software after a Configuration
Mismatch Reset occurs)
bit 4 RI: RESET Instruction Flag bit
1 = The RESET instruction was not executed (set by firmware only)
0 = The RESET instruction was executed causing a device Reset (must be set in software after a
Brown-out Reset occurs)
bit 3 TO: Watchdog Time-out Flag bit
1 = Set by power-up, CLRWDT instruction or SLEEP instruction
0 = A WDT time-out occurred
bit 2 PD: Power-Down Detection Flag bit
1 = Set by power-up or by the CLRWDT instruction
0 = Set by execution of the SLEEP instruction
bit 1 POR: Power-on Reset Status bit
1 = A Power-on Reset has not occurred (set by firmware only)
0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)
bit 0 BOR: Brown-out Reset Status bit
1 = A Brown-out Reset has not occurred (set by firmware only)
0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs)
Note 1: It is recommended that the POR bit be set after a Power-on Reset has been detected, so that subsequent
Power-on Resets may be detected.
2: If the on-chip voltage regulator is disabled, BOR remains 0’ at all times. See Section 4.4.1 “Detecting
BOR” for more information.
3: Brown-out Reset is said to have occurred when BOR is ‘0’ and POR is ‘1’ (assuming that POR was set to
1’ by software immediately after a Power-on Reset).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 51
PIC18F87J11 FAMILY
4.2 Master Clear (MCLR)
The MCLR pin provides a method for triggering a hard
external Reset of the device. A Reset is generated by
holding the pin low. PIC18 extended microcontroller
devices have a noise filter in the MCLR Reset path
which detects and ignores small pulses.
The MCLR pin is not driven low by any internal Resets,
including the WDT.
4.3 Power-on Reset (POR)
A Power-on Reset condition is generated on-chip
whenever VDD rises above a certain threshold. This
allows the device to start in the initialized state when
VDD is adequate for operation.
To take advantage of the POR circuitry, tie the MCLR
pin through a resistor (1 kΩ to 10 kΩ) to VDD. This will
eliminate external RC components usually needed to
create a Power-on Reset delay. A minimum rise rate for
VDD is specified (parameter D004). For a slow rise
time, see Figure 4-2.
When the device starts normal operation (i.e., exits the
Reset condition), device operating parameters
(voltage, frequency, temperature, etc.) must be met to
ensure operation. If these conditions are not met, the
device must be held in Reset until the operating
conditions are met.
Power-on Reset events are captured by the POR bit
(RCON<1>). The state of the bit is set to ‘0’ whenever
a Power-on Reset occurs; it does not change for any
other Reset event. POR is not reset to ‘1’ by any
hardware event. To capture multiple events, the user
manually resets the bit to1’ in software following any
Power-on Reset.
4.4 Brown-out Reset (BOR)
The PIC18F87J11 family of devices incorporates a
simple Brown-out Reset function when the internal reg-
ulator is enabled (ENVREG pin is tied to VDD). Any
drop of VDD below VBOR (parameter D005)) for greater
than time TBOR (parameter 35) will reset the device. A
Reset may or may not occur if VDD falls below VBOR for
less than TBOR. The chip will remain in Brown-out
Reset until VDD rises above VBOR.
Once a Brown-out Reset has occurred, the Power-up
Timer will keep the chip in Reset for TPWRT
(parameter 33). If VDD drops below VBOR while the
Power-up Timer is running, the chip will go back into a
Brown-out Reset and the Power-up Timer will be
initialized. Once VDD rises above VBOR, the Power-up
Timer will execute the additional time delay.
FIGURE 4-2: EXTERNAL POWER-ON
RESET CIRCUIT (FOR
SLOW VDD POWER-UP)
4.4.1 DETECTING BOR
The BOR bit always resets to ‘0’ on any Brown-out
Reset or Power-on Reset event. This makes it difficult
to determine if a Brown-out Reset event has occurred
just by reading the state of BOR alone. A more reliable
method is to simultaneously check the state of both
POR and BOR. This assumes that the POR bit is reset
to ‘1’ in software immediately after any Power-on Reset
event. If BOR is ‘0’ while POR is ‘1’, it can be reliably
assumed that a Brown-out Reset event has occurred.
If the voltage regulator is disabled, Brown-out Reset
functionality is disabled. In this case, the BOR bit
cannot be used to determine a Brown-out Reset event.
The BOR bit is still cleared by a Power-on Reset event.
4.5 Configuration Mismatch (CM)
The Configuration Mismatch (CM) Reset is designed to
detect and attempt to recover from random, memory
corrupting events. These include Electrostatic Discharge
(ESD) events, which can cause widespread, single-bit
changes throughout the device and result in catastrophic
failure.
In PIC18FXXJ Flash devices, the device Configuration
registers (located in the configuration memory space)
are continuously monitored during operation by
comparing their values to complimentary shadow reg-
isters. If a mismatch is detected between the two sets
of registers, a CM Reset automatically occurs. These
events are captured by the CM bit (RCON<5>). The
state of the bit is set to ‘0’ whenever a CM event occurs;
it does not change for any other Reset event.
Note 1: External Power-on Reset circuit is required
only if the VDD power-up slope is too slow.
The diode D helps discharge the capacitor
quickly when VDD powers down.
2: R < 40 kΩ is recommended to make sure that
the voltage drop across R does not violate
the device’s electrical specification.
3: R1 1 kΩ will limit any current flowing into
MCLR from external capacitor C, in the event
of MCLR/VPP pin breakdown, due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS).
C
R1
R
D
VDD
MCLR
PIC18F87J11
VDD
PIC18F87J11 FAMILY
DS39778C-page 52 Preliminary © 2008 Microchip Technology Inc.
A CM Reset behaves similarly to a Master Clear Reset,
RESET instruction, WDT time-out or Stack Event
Resets. As with all hard and power Reset events, the
device Configuration Words are reloaded from the
Flash Configuration Words in program memory as the
device restarts.
4.6 Power-up Timer (PWRT)
PIC18F87J11 Family devices incorporate an on-chip
Power-up Timer (PWRT) to help regulate the Power-on
Reset process. The PWRT is always enabled. The
main function is to ensure that the device voltage is
stable before code is executed.
The Power-up Timer (PWRT) of the PIC18F87J11
Family devices is an 11-bit counter which uses the
INTRC source as the clock input. This yields an
approximate time interval of 2048 x 32 μs=66ms.
While the PWRT is counting, the device is held in
Reset.
The power-up time delay depends on the INTRC clock
and will vary from chip-to-chip due to temperature and
process variation. See DC parameter 33 for details.
4.6.1 TIME-OUT SEQUENCE
If enabled, the PWRT time-out is invoked after the POR
pulse has cleared. The total time-out will vary based on
the status of the PWRT. Figure 4-3, Figure 4-4,
Figure 4-5 and Figure 4-6 all depict time-out
sequences on power-up with the Power-up Timer
enabled.
Since the time-outs occur from the POR pulse, if MCLR
is kept low long enough, the PWRT will expire. Bringing
MCLR high will begin execution immediately
(Figure 4-5). This is useful for testing purposes, or to
synchronize more than one PIC18FXXXX device
operating in parallel.
FIGURE 4-3: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT)
FIGURE 4-4: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1
TPWRT
VDD
MCLR
INTERNAL POR
PWRT TIME-OUT
INTERNAL RESET
TPWRT
VDD
MCLR
INTERNAL POR
PWRT TIME-OUT
INTERNAL RESET
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 53
PIC18F87J11 FAMILY
FIGURE 4-5: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2
FIGURE 4-6: SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT)
VDD
MCLR
INTERNAL POR
PWRT TIME-OUT
INTERNAL RESET
TPWRT
VDD
MCLR
INTERNAL POR
PWRT TIME-OUT
INTERNAL RESET
0V 1V
3.3V
TPWRT
PIC18F87J11 FAMILY
DS39778C-page 54 Preliminary © 2008 Microchip Technology Inc.
4.7 Reset State of Registers
Most registers are unaffected by a Reset. Their status
is unknown on POR and unchanged by all other
Resets. The other registers are forced to a “Reset
state” depending on the type of Reset that occurred.
Most registers are not affected by a WDT wake-up,
since this is viewed as the resumption of normal
operation. Status bits from the RCON register (CM, RI,
TO, PD, POR and BOR) are set or cleared differently in
different Reset situations, as indicated in Table 4-1.
These bits are used in software to determine the nature
of the Reset.
Table 4-2 describes the Reset states for all of the
Special Function Registers. These are categorized by
Power-on and Brown-out Resets, Master Clear and
WDT Resets and WDT wake-ups.
TABLE 4-1: STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR
RCON REGISTER
Condition Program
Counter(1)
RCON Register STKPTR Register
CM RI TO PD POR BOR STKFUL STKUNF
Power-on Reset 0000h 111100 0 0
RESET instruction 0000h u0uuuu u u
Brown-out Reset 0000h 1111u0 u u
Configuration Mismatch Reset 0000h 0uuuuu u u
MCLR Reset during
power-managed Run modes
0000h uu1uuu u u
MCLR Reset during
power-managed Idle modes
and Sleep mode
0000h uu10uu u u
MCLR Reset during full-power
execution
0000h uuuuuu u u
Stack Full Reset (STVREN = 1) 0000h uuuuuu 1 u
Stack Underflow Reset
(STVREN = 1)
0000h uuuuuu u 1
Stack Underflow Error (not an
actual Reset, STVREN = 0)
0000h uuuuuu u 1
WDT time-out during full-power
or power-managed Run modes
0000h uu0uuu u u
WDT time-out during
power-managed Idle or Sleep
modes
PC + 2 uu00uu u u
Interrupt exit from
power-managed modes
PC + 2 uuu0uu u u
Legend: u = unchanged
Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 55
PIC18F87J11 FAMILY
TABLE 4-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS
Register Applicable Devices Power-on Reset,
Brown-out Reset
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets,
CM Resets
Wake-up via WDT
or Interrupt
TOSU PIC18F6XJ1X PIC18F8XJ1X ---0 0000 ---0 0000 ---0 uuuu(1)
TOSH PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu(1)
TOSL PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu(1)
STKPTR PIC18F6XJ1X PIC18F8XJ1X 00-0 0000 uu-0 0000 uu-u uuuu(1)
PCLATU PIC18F6XJ1X PIC18F8XJ1X ---0 0000 ---0 0000 ---u uuuu
PCLATH PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PCL PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 PC + 2(2)
TBLPTRU PIC18F6XJ1X PIC18F8XJ1X --00 0000 --00 0000 --uu uuuu
TBLPTRH PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
TBLPTRL PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
TABLAT PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PRODH PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
PRODL PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
INTCON PIC18F6XJ1X PIC18F8XJ1X 0000 000x 0000 000u uuuu uuuu(3)
INTCON2 PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu(3)
INTCON3 PIC18F6XJ1X PIC18F8XJ1X 1100 0000 1100 0000 uuuu uuuu(3)
INDF0 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
POSTINC0 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
POSTDEC0 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
PREINC0 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
PLUSW0 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
FSR0H PIC18F6XJ1X PIC18F8XJ1X ---- xxxx ---- uuuu ---- uuuu
FSR0L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
WREG PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
INDF1 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
POSTINC1 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
POSTDEC1 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
PREINC1 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
PLUSW1 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
FSR1H PIC18F6XJ1X PIC18F8XJ1X ---- xxxx ---- uuuu ---- uuuu
FSR1L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
BSR PIC18F6XJ1X PIC18F8XJ1X ---- 0000 ---- 0000 ---- uuuu
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as0’, q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are
updated with the current value of the PC. The STKPTR is modified to point to the next location in the
hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Table 4-1 for Reset value for specific condition.
PIC18F87J11 FAMILY
DS39778C-page 56 Preliminary © 2008 Microchip Technology Inc.
INDF2 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
POSTINC2 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
POSTDEC2 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
PREINC2 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
PLUSW2 PIC18F6XJ1X PIC18F8XJ1X N/A N/A N/A
FSR2H PIC18F6XJ1X PIC18F8XJ1X ---- xxxx ---- uuuu ---- uuuu
FSR2L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
STATUS PIC18F6XJ1X PIC18F8XJ1X ---x xxxx ---u uuuu ---u uuuu
TMR0H PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
TMR0L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
T0CON PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu
OSCCON PIC18F6XJ1X PIC18F8XJ1X 0110 q100 0110 q100 0110 q10u
REFOCON PIC18F6XJ1X PIC18F8XJ1X 0-00 0000 u-uu uuuu u-uu uuuu
CM1CON PIC18F6XJ1X PIC18F8XJ1X 0001 1111 uuuu uuuu uuuu uuuu
CM2CON PIC18F6XJ1X PIC18F8XJ1X 0001 1111 uuuu uuuu uuuu uuuu
RCON(4) PIC18F6XJ1X PIC18F8XJ1X 0-11 1100 0-qq qquu u-qq qquu
TMR1H PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
ODCON1 PIC18F6XJ1X PIC18F8XJ1X ---0 0000 ---u uuuu ---u uuuu
TMR1L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
ODCON2 PIC18F6XJ1X PIC18F8XJ1X ---- --00 ---- --uu ---- --uu
T1CON PIC18F6XJ1X PIC18F8XJ1X 0000 0000 u0uu uuuu uuuu uuuu
ODCON3 PIC18F6XJ1X PIC18F8XJ1X ---- --00 ---- --uu ---- --uu
TMR2 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PADCFG1 PIC18F6XJ1X PIC18F8XJ1X ---- ---0 ---- ---u ---- ---u
PR2 PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 1111 1111
MEMCON PIC18F6XJ1X PIC18F8XJ1X 0-00 --00 0-00 --00 u-uu --uu
T2CON PIC18F6XJ1X PIC18F8XJ1X -000 0000 -000 0000 -uuu uuuu
SSP1BUF PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
SSP1ADD PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
SSP1MSK PIC18F6XJ1X PIC18F8XJ1X 1111 1111 uuuu uuuu uuuu uuuu
SSP1STAT PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
SSP1CON1 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
SSP1CON2 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
TABLE 4-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices Power-on Reset,
Brown-out Reset
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets,
CM Resets
Wake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as0’, q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are
updated with the current value of the PC. The STKPTR is modified to point to the next location in the
hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Table 4-1 for Reset value for specific condition.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 57
PIC18F87J11 FAMILY
ADRESH PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
ADRESL PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
ADCON0 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
ADCON1 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
ANCON0 PIC18F6XJ1X PIC18F8XJ1X 00-0 0000 uu-u uuuu uu-u uuuu
ANCON1 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 uuuu uuuu uuuu uuuu
WDTCON PIC18F6XJ1X PIC18F8XJ1X 0x-0 ---0 0x-u ---0 ux-u ---u
ECCP1AS PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
ECCP1DEL PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
CCPR1H PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
CCPR1L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
CCP1CON PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
ECCP2AS PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
ECCP2DEL PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
CCPR2H PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
CCPR2L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
CCP2CON PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
ECCP3AS PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
ECCP3DEL PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
CCPR3H PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
CCPR3L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
CCP3CON PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
SPBRG1 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
RCREG1 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
TXREG1 PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
TXSTA1 PIC18F6XJ1X PIC18F8XJ1X 0000 0010 0000 0010 uuuu uuuu
RCSTA1 PIC18F6XJ1X PIC18F8XJ1X 0000 000x 0000 000x uuuu uuuu
SPBRG2 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
RCREG2 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
TXREG2 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
TXSTA2 PIC18F6XJ1X PIC18F8XJ1X 0000 0010 0000 0010 uuuu uuuu
EECON2 PIC18F6XJ1X PIC18F8XJ1X ---- ---- ---- ---- ---- ----
EECON1 PIC18F6XJ1X PIC18F8XJ1X --00 x00- --00 u00- --00 u00-
TABLE 4-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices Power-on Reset,
Brown-out Reset
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets,
CM Resets
Wake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as0’, q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are
updated with the current value of the PC. The STKPTR is modified to point to the next location in the
hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Table 4-1 for Reset value for specific condition.
PIC18F87J11 FAMILY
DS39778C-page 58 Preliminary © 2008 Microchip Technology Inc.
IPR3 PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu
PIR3 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu(3)
PIE3 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
IPR2 PIC18F6XJ1X PIC18F8XJ1X 111- 1111 111- 1111 uuu- uuuu
PIR2 PIC18F6XJ1X PIC18F8XJ1X 000- 0000 000- 0000 uuu- uuuu(3)
PIE2 PIC18F6XJ1X PIC18F8XJ1X 000- 0000 000- 0000 uuu- uuuu
IPR1 PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu
PIR1 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu(3)
PIE1 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
RCSTA2 PIC18F6XJ1X PIC18F8XJ1X 0000 000x 0000 000x uuuu uuuu
OSCTUNE PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
TRISJ PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu
TRISH PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu
TRISG PIC18F6XJ1X PIC18F8XJ1X ---1 1111 ---1 1111 ---u uuuu
TRISF PIC18F6XJ1X PIC18F8XJ1X 1111 111- 1111 111- uuuu uuu-
TRISE PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu
TRISD PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu
TRISC PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu
TRISB PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu
TRISA PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 uuuu uuuu
LATJ PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
LATH PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
LATG PIC18F6XJ1X PIC18F8XJ1X ---x xxxx ---u uuuu ---u uuuu
LATF PIC18F6XJ1X PIC18F8XJ1X xxxx xxx- uuuu uuu- uuuu uuu-
LATE PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
LATD PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
LATC PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
LATB PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
LATA PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
TABLE 4-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices Power-on Reset,
Brown-out Reset
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets,
CM Resets
Wake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as0’, q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are
updated with the current value of the PC. The STKPTR is modified to point to the next location in the
hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Table 4-1 for Reset value for specific condition.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 59
PIC18F87J11 FAMILY
PORTJ PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
PORTH PIC18F6XJ1X PIC18F8XJ1X 0000 xxxx uuuu uuuu uuuu uuuu
PORTG PIC18F6XJ1X PIC18F8XJ1X 000x xxxx 000u uuuu uuuu uuuu
PORTF PIC18F6XJ1X PIC18F8XJ1X x001 100- xuuu uuu- xuuu uuu-
PORTE PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
PORTD PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
PORTC PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
PORTB PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
PORTA PIC18F6XJ1X PIC18F8XJ1X 000x 0000 000u 0000 uuuu uuuu
SPBRGH1 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
BAUDCON1 PIC18F6XJ1X PIC18F8XJ1X 0100 0-00 0100 0-00 uuuu u-uu
SPBRGH2 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
BAUDCON2 PIC18F6XJ1X PIC18F8XJ1X 0100 0-00 0100 0-00 uuuu u-uu
TMR3H PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
TMR3L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
T3CON PIC18F6XJ1X PIC18F8XJ1X 0000 0000 uuuu uuuu uuuu uuuu
TMR4 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PR4 PIC18F6XJ1X PIC18F8XJ1X 1111 1111 1111 1111 1111 1111
CVRCON PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
T4CON PIC18F6XJ1X PIC18F8XJ1X -000 0000 -000 0000 -uuu uuuu
CCPR4H PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
CCPR4L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
CCP4CON PIC18F6XJ1X PIC18F8XJ1X --00 0000 --00 0000 --uu uuuu
CCPR5H PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
CCPR5L PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
CCP5CON PIC18F6XJ1X PIC18F8XJ1X --00 0000 --00 0000 --uu uuuu
SSP2BUF PIC18F6XJ1X PIC18F8XJ1X xxxx xxxx uuuu uuuu uuuu uuuu
SSP2ADD PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
SSP2MSK PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
SSP2STAT PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
SSP2CON1 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
SSP2CON2 PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
CMSTAT PIC18F6XJ1X PIC18F8XJ1X ---- --11 ---- --11 ---- --uu
TABLE 4-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices Power-on Reset,
Brown-out Reset
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets,
CM Resets
Wake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as0’, q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are
updated with the current value of the PC. The STKPTR is modified to point to the next location in the
hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Table 4-1 for Reset value for specific condition.
PIC18F87J11 FAMILY
DS39778C-page 60 Preliminary © 2008 Microchip Technology Inc.
PMADDRH PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMDOUT1H PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMADDRL PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMDOUT1L PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMDIN1H PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMDIN1L PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMCONH PIC18F6XJ1X PIC18F8XJ1X 0-00 0000 0-00 0000 u-uu uuuu
PMCONL PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMMODEH PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMMODEL PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMDOUT2H PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMDOUT2L PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMDIN2H PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMDIN2L PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMEH PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMEL PIC18F6XJ1X PIC18F8XJ1X 0000 0000 0000 0000 uuuu uuuu
PMSTATH PIC18F6XJ1X PIC18F8XJ1X 00-- 0000 00-- 0000 uu-- uuuu
PMSTATL PIC18F6XJ1X PIC18F8XJ1X 10-- 1111 10-- 1111 uu-- uuuu
TABLE 4-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices Power-on Reset,
Brown-out Reset
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets,
CM Resets
Wake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as0’, q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are
updated with the current value of the PC. The STKPTR is modified to point to the next location in the
hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Table 4-1 for Reset value for specific condition.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 61
PIC18F87J11 FAMILY
5.0 MEMORY ORGANIZATION
There are two types of memory in PIC18 Flash
microcontroller devices:
Program Memory
Data RAM
As Harvard architecture devices, the data and program
memories use separate busses; this allows for
concurrent access of the two memory spaces.
Additional detailed information on the operation of the
Flash program memory is provided in Section 6.0
“Flash Program Memory”.
5.1 Program Memory Organization
PIC18 microcontrollers implement a 21-bit program
counter which is capable of addressing a 2-Mbyte
program memory space. Accessing a location between
the upper boundary of the physically implemented
memory and the 2-Mbyte address will return all ‘0’s (a
NOP instruction).
The entire PIC18F87J11 Family of devices offers three
different on-chip Flash program memory sizes, from
64 Kbytes (up to 16,384 single-word instructions) to
128 Kbytes (65,536 single-word instructions). The
program memory maps for individual family members
are shown in Figure 5-3.
FIGURE 5-1: MEMORY MAPS FOR PIC18F87J11 FAMILY DEVICES
Note: Sizes of memory areas are not to scale. Sizes of program memory areas are enhanced to show detail.
Unimplemented
Read as ‘0
Unimplemented
Read as ‘0
000000h
1FFFFFF
PIC18FX6J11 PIC18FX6J16 PIC18FX7J11
00FFFFh
017FFFh
PC<20:0>
Stack Level 1
Stack Level 31
CALL, CALLW, RCALL,
RETURN, RETFIE, RETLW,
21
User Memory Space
On-Chip
Memory
On-Chip
Memory
On-Chip
Memory
ADDULNK, SUBULNK
Config. Words
Config. Words
Config. Words 01FFFFh
Unimplemented
Read as ‘0
PIC18F87J11 FAMILY
DS39778C-page 62 Preliminary © 2008 Microchip Technology Inc.
5.1.1 HARD MEMORY VECTORS
All PIC18 devices have a total of three hard-coded
return vectors in their program memory space. The
Reset vector address is the default value to which the
program counter returns on all device Resets; it is
located at 0000h.
PIC18 devices also have two interrupt vector
addresses for the handling of high-priority and
low-priority interrupts. The high-priority interrupt vector
is located at 0008h and the low-priority interrupt vector
is at 0018h. Their locations in relation to the program
memory map are shown in Figure 5-2.
FIGURE 5-2: HARD VECTOR AND
CONFIGURATION WORD
LOCATIONS FOR
PIC18F87J11 FAMILY
DEVICES
5.1.2 FLASH CONFIGURATION WORDS
Because PIC18F87J11 Family devices do not have
persistent configuration memory, the top four words of
on-chip program memory are reserved for configuration
information. On Reset, the configuration information is
copied into the Configuration registers.
The Configuration Words are stored in their program
memory location in numerical order, starting with the
lower byte of CONFIG1 at the lowest address and
ending with the upper byte of CONFIG4. For these
devices, only Configuration Words, CONFIG1 through
CONFIG3, are used; CONFIG4 is reserved. The actual
addresses of the Flash Configuration Word for devices
in the PIC18F87J11 Family are shown in Table 5-1.
Their location in the memory map is shown with the
other memory vectors in Figure 5-2.
Additional details on the device Configuration Words
are provided in Section 24.1 “Configuration Bits”.
TABLE 5-1: FLASH CONFIGURATION
WORD FOR PIC18F87J11
FAMILY DEVICES
Reset Vector
Low-Priority Interrupt Vector
0000h
0018h
On-Chip
Program Memory
High-Priority Interrupt Vector 0008h
1FFFFFh
(Top of Memory)
(Top of Memory-7)
Flash Configuration Words
Read as ‘0
Legend: (Top of Memory) represents upper boundary
of on-chip program memory space (see
Figure 5-1 for device-specific values).
Shaded area represents unimplemented
memory. Areas are not shown to scale.
Device
Program
Memory
(Kbytes)
Configuration
Word
Addresses
PIC18F66J11 64 FFF8h to
FFFFh
PIC18F86J11
PIC18F66J16 96 17FF8h to
17FFFh
PIC18F86J16
PIC18F67J11 128 1FFF8h to
1FFFFh
PIC18F87J11
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 63
PIC18F87J11 FAMILY
5.1.3 PIC18F8XJ11/8XJ16 PROGRAM
MEMORY MODES
The 80-pin devices in this family can address up to a
total of 2 Mbytes of program memory. This is achieved
through the external memory bus. There are two
distinct operating modes available to the controllers:
Microcontroller (MC)
Extended Microcontroller (EMC)
The program memory mode is determined by setting
the EMB Configuration bits (CONFIG3L<5:4>), as
shown in Register 5-1. (See also Section 24.1
“Configuration Bits” for additional details on the
device Configuration bits.)
The program memory modes operate as follows:
•The Microcontroller Mode accesses only on-chip
Flash memory. Attempts to read above the top of
on-chip memory causes a read of all ‘0’s (a NOP
instruction).
The Microcontroller mode is also the only operating
mode available to 64-pin devices.
•The Extended Microcontroller Mode allows
access to both internal and external program
memories as a single block. The device can
access its entire on-chip program memory; above
this, the device accesses external program
memory up to the 2-Mbyte program space limit.
Execution automatically switches between the
two memories as required.
The setting of the EMB Configuration bits also controls
the address bus width of the external memory bus. This
is covered in more detail in Section 7.0 “External
Memory Bus”.
In all modes, the microcontroller has complete access
to data RAM.
Figure 5-3 compares the memory maps of the different
program memory modes. The differences between
on-chip and external memory access limitations are
more fully explained in Table 5-2.
REGISTER 5-1: CONFIG3L: CONFIGURATION REGISTER 3 LOW
R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1 U-0 U-0 U-0
WAIT(1) BW(1) EMB1(1) EMB0(1) EASHFT(1)
bit 7 bit 0
Legend: WO = Write-Once bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 WAIT: External Bus Wait Enable bit(1)
1 = Wait states on the external bus are disabled
0 = Wait states on the external bus are enabled and selected by MEMCON<5:4>
bit 6 BW: Data Bus Width Select bit(1)
1 = 16-Bit Data Width modes
0 = 8-Bit Data Width modes
bit 5-4 EMB1:EMB0: External Memory Bus Configuration bits(1)
11 = Microcontroller mode, external bus disabled
10 = Extended Microcontroller mode, 12-bit address width for external bus
01 = Extended Microcontroller mode, 16-bit address width for external bus
00 = Extended Microcontroller mode, 20-bit address width for external bus
bit 3 EASHFT: External Address Bus Shift Enable bit(1)
1 = Address shifting enabled – external address bus is shifted to start at 000000h
0 = Address shifting disabled – external address bus reflects the PC value
bit 2-0 Unimplemented: Read as ‘0
Note 1: Implemented only on 80-pin devices.
PIC18F87J11 FAMILY
DS39778C-page 64 Preliminary © 2008 Microchip Technology Inc.
5.1.4 EXTENDED MICROCONTROLLER
MODE AND ADDRESS SHIFTING
By default, devices in Extended Microcontroller mode
directly present the program counter value on the
external address bus for those addresses in the range
of the external memory space. In practical terms, this
means addresses in the external memory device below
the top of on-chip memory are unavailable.
To avoid this, the Extended Microcontroller mode
implements an address shifting option to enable auto-
matic address translation. In this mode, addresses
presented on the external bus are shifted down by the
size of the on-chip program memory and are remapped
to start at 0000h. This allows the complete use of the
external memory device’s memory space as an
extension of the device’s on-chip program memory.
FIGURE 5-3: MEMORY MAPS FOR PIC18F87J11 FAMILY PROGRAM MEMORY MODES
TABLE 5-2: MEMORY ACCESS FOR PIC18F8X11/8616 PROGRAM MEMORY MODES
External
Memory
On-Chip
Program
Memory
Microcontroller Mode(1)
000000h
On-Chip
Program
Memory
1FFFFFh
Reads
as ‘0’s
External On-Chip
Memory Memory
(Top of Memory)
(Top of Memory) + 1
Legend: (Top of Memory) represents upper boundary of on-chip program memory space (see Figure 5-1 for device-specific
values). Shaded areas represent unimplemented, or inaccessible areas, depending on the mode.
Note 1: This mode is the only available mode on 64-pin devices and the default on 80-pin devices.
2: These modes are only available on 80-pin devices.
3: Addresses starting at the top of the program memory are translated to start at 0000h of the external device
whenever the EASHFT Configuration bit is set.
Extended Microcontroller Mode(2)
000000h
1FFFFFh
(Top of Memory)
(Top of Memory) + 1 External
Memory
On-Chip
Program
Memory
000000h
1FFFFFh
(Top of Memory)
(Top of Memory) + 1(3)
No
Access
Space
On-Chip
Memory
Space
External On-Chip
Memory Memory
Space
Mapped
to
External
Memory
Space
Space Space
Mapped
to
External
Memory
Space (Top of Memory)
Extended Microcontroller Mode
with Address Shifting(2)
1FFFFFh –
Operating Mode
Internal Program Memory External Program Memory
Execution
From
Table Read
From
Table Write
To
Execution
From
Table Read
From
Table Write
To
Microcontroller Yes Yes Yes No Access No Access No Access
Extended Microcontroller Yes Yes Yes Yes Yes Yes
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 65
PIC18F87J11 FAMILY
5.1.5 PROGRAM COUNTER
The Program Counter (PC) specifies the address of the
instruction to fetch for execution. The PC is 21 bits wide
and is contained in three separate 8-bit registers. The
low byte, known as the PCL register, is both readable
and writable. The high byte, or PCH register, contains
the PC<15:8> bits; it is not directly readable or writable.
Updates to the PCH register are performed through the
PCLATH register. The upper byte is called PCU. This
register contains the PC<20:16> bits; it is also not
directly readable or writable. Updates to the PCU
register are performed through the PCLATU register.
The contents of PCLATH and PCLATU are transferred
to the program counter by any operation that writes
PCL. Similarly, the upper two bytes of the program
counter are transferred to PCLATH and PCLATU by an
operation that reads PCL. This is useful for computed
offsets to the PC (see Section 5.1.8.1 “Computed
GOTO”).
The PC addresses bytes in the program memory. To
prevent the PC from becoming misaligned with word
instructions, the Least Significant bit of PCL is fixed to
a value of0’. The PC increments by 2 to address
sequential instructions in the program memory.
The CALL, RCALL, GOTO and program branch
instructions write to the program counter directly. For
these instructions, the contents of PCLATH and
PCLATU are not transferred to the program counter.
5.1.6 RETURN ADDRESS STACK
The return address stack allows any combination of up
to 31 program calls and interrupts to occur. The PC is
pushed onto the stack when a CALL or RCALL instruc-
tion is executed, or an interrupt is Acknowledged. The
PC value is pulled off the stack on a RETURN, RETLW
or a RETFIE instruction (and on ADDULNK and
SUBULNK instructions if the extended instruction set is
enabled). PCLATU and PCLATH are not affected by
any of the RETURN or CALL instructions.
The stack operates as a 31-word by 21-bit RAM and a
5-bit Stack Pointer, STKPTR. The stack space is not
part of either program or data space. The Stack Pointer
is readable and writable and the address on the top of
the stack is readable and writable through the
Top-of-Stack Special Function Registers. Data can also
be pushed to, or popped from the stack, using these
registers.
A CALL type instruction causes a push onto the stack.
The Stack Pointer is first incremented and the location
pointed to by the Stack Pointer is written with the
contents of the PC (already pointing to the instruction
following the CALL). A RETURN type instruction causes
a pop from the stack. The contents of the location
pointed to by the STKPTR are transferred to the PC
and then the Stack Pointer is decremented.
The Stack Pointer is initialized to ‘00000’ after all
Resets. There is no RAM associated with the location
corresponding to a Stack Pointer value of00000’; this
is only a Reset value. Status bits indicate if the stack is
full, has overflowed or has underflowed.
5.1.6.1 Top-of-Stack Access
Only the top of the return address stack (TOS) is
readable and writable. A set of three registers,
TOSU:TOSH:TOSL, hold the contents of the stack loca-
tion pointed to by the STKPTR register (Figure 5-4). This
allows users to implement a software stack if necessary.
After a CALL, RCALL or interrupt (and ADDULNK and
SUBULNK instructions if the extended instruction set is
enabled), the software can read the pushed value by
reading the TOSU:TOSH:TOSL registers. These values
can be placed on a user-defined software stack. At
return time, the software can return these values to
TOSU:TOSH:TOSL and do a return.
The user must disable the global interrupt enable bits
while accessing the stack to prevent inadvertent stack
corruption.
FIGURE 5-4: RETURN ADDRESS STACK AND ASSOCIATED REGISTERS
00011
001A34h
11111
11110
11101
00010
00001
00000
00010
Return Address Stack <20:0>
To p - o f - St a c k
000D58h
TOSLTOSHTOSU
34h1Ah00h
STKPTR<4:0>
Top-of-Stack Registers Stack Pointer
PIC18F87J11 FAMILY
DS39778C-page 66 Preliminary © 2008 Microchip Technology Inc.
5.1.6.2 Return Stack Pointer (STKPTR)
The STKPTR register (Register 5-2) contains the Stack
Pointer value, the STKFUL (Stack Full) status bit and
the STKUNF (Stack Underflow) status bits. The value
of the Stack Pointer can be 0 through 31. The Stack
Pointer increments before values are pushed onto the
stack and decrements after values are popped off the
stack. On Reset, the Stack Pointer value will be zero.
The user may read and write the Stack Pointer value.
This feature can be used by a Real-Time Operating
System (RTOS) for return stack maintenance.
After the PC is pushed onto the stack 31 times (without
popping any values off the stack), the STKFUL bit is
set. The STKFUL bit is cleared by software or by a
POR.
The action that takes place when the stack becomes
full depends on the state of the STVREN (Stack Over-
flow Reset Enable) Configuration bit. (Refer to
Section 24.1 “Configuration Bits” for a description of
the device Configuration bits.) If STVREN is set
(default), the 31st push will push the (PC + 2) value
onto the stack, set the STKFUL bit and reset the
device. The STKFUL bit will remain set and the Stack
Pointer will be set to zero.
If STVREN is cleared, the STKFUL bit will be set on the
31st push and the Stack Pointer will increment to 31.
Any additional pushes will not overwrite the 31st push
and the STKPTR will remain at 31.
When the stack has been popped enough times to
unload the stack, the next pop will return a value of zero
to the PC and set the STKUNF bit, while the Stack
Pointer remains at zero. The STKUNF bit will remain
set until cleared by software or until a POR occurs.
5.1.6.3 PUSH and POP Instructions
Since the Top-of-Stack is readable and writable, the
ability to push values onto the stack and pull values off
the stack, without disturbing normal program execu-
tion, is a desirable feature. The PIC18 instruction set
includes two instructions, PUSH and POP, that permit
the TOS to be manipulated under software control.
TOSU, TOSH and TOSL can be modified to place data
or a return address on the stack.
The PUSH instruction places the current PC value onto
the stack. This increments the Stack Pointer and loads
the current PC value onto the stack.
The POP instruction discards the current TOS by
decrementing the Stack Pointer. The previous value
pushed onto the stack then becomes the TOS value.
Note: Returning a value of zero to the PC on an
underflow has the effect of vectoring the
program to the Reset vector, where the
stack conditions can be verified and
appropriate actions can be taken. This is
not the same as a Reset, as the contents
of the SFRs are not affected.
REGISTER 5-2: STKPTR: STACK POINTER REGISTER
R/C-0 R/C-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
STKFUL(1) STKUNF(1) SP4 SP3 SP2 SP1 SP0
bit 7 bit 0
Legend: C = Clearable-only bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 STKFUL: Stack Full Flag bit(1)
1 = Stack became full or overflowed
0 = Stack has not become full or overflowed
bit 6 STKUNF: Stack Underflow Flag bit(1)
1 = Stack underflow occurred
0 = Stack underflow did not occur
bit 5 Unimplemented: Read as0
bit 4-0 SP4:SP0: Stack Pointer Location bits
Note 1: Bit 7 and bit 6 are cleared by user software or by a POR.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 67
PIC18F87J11 FAMILY
5.1.6.4 Stack Full and Underflow Resets
Device Resets on stack overflow and stack underflow
conditions are enabled by setting the STVREN bit in
Configuration Register 1L. When STVREN is set, a full
or underflow condition will set the appropriate STKFUL
or STKUNF bit and then cause a device Reset. When
STVREN is cleared, a full or underflow condition will set
the appropriate STKFUL or STKUNF bit, but not cause
a device Reset. The STKFUL or STKUNF bits are
cleared by the user software or a Power-on Reset.
5.1.7 FAST REGISTER STACK
A Fast Register Stack is provided for the STATUS,
WREG and BSR registers to provide a “fast return”
option for interrupts. This stack is only one level deep
and is neither readable nor writable. It is loaded with the
current value of the corresponding register when the
processor vectors for an interrupt. All interrupt sources
will push values into the Stack registers. The values in
the registers are then loaded back into the working
registers if the RETFIE, FAST instruction is used to
return from the interrupt.
If both low and high-priority interrupts are enabled, the
Stack registers cannot be used reliably to return from
low-priority interrupts. If a high-priority interrupt occurs
while servicing a low-priority interrupt, the Stack
register values stored by the low-priority interrupt will
be overwritten. In these cases, users must save the key
registers in software during a low-priority interrupt.
If interrupt priority is not used, all interrupts may use the
Fast Register Stack for returns from interrupt. If no
interrupts are used, the Fast Register Stack can be
used to restore the STATUS, WREG and BSR registers
at the end of a subroutine call. To use the Fast Register
Stack for a subroutine call, a CALL label, FAST
instruction must be executed to save the STATUS,
WREG and BSR registers to the Fast Register Stack. A
RETURN, FAST instruction is then executed to restore
these registers from the Fast Register Stack.
Example 5-1 shows a source code example that uses
the Fast Register Stack during a subroutine call and
return.
EXAMPLE 5-1: FAST REGISTER STACK
CODE EXAMPLE
5.1.8 LOOK-UP TABLES IN PROGRAM
MEMORY
There may be programming situations that require the
creation of data structures, or look-up tables, in
program memory. For PIC18 devices, look-up tables
can be implemented in two ways:
Computed GOTO
Table Reads
5.1.8.1 Computed GOTO
A computed GOTO is accomplished by adding an offset
to the program counter. An example is shown in
Example 5-2.
A look-up table can be formed with an ADDWF PCL
instruction and a group of RETLW nn instructions. The
W register is loaded with an offset into the table before
executing a call to that table. The first instruction of the
called routine is the ADDWF PCL instruction. The next
instruction executed will be one of the RETLW nn
instructions that returns the value ‘nn’ to the calling
function.
The offset value (in WREG) specifies the number of
bytes that the program counter should advance and
should be multiples of 2 (LSb = 0).
In this method, only one data byte may be stored in
each instruction location and room on the return
address stack is required.
EXAMPLE 5-2: COMPUTED GOTO USING
AN OFFSET VALUE
5.1.8.2 Table Reads
A better method of storing data in program memory
allows two bytes of data to be stored in each instruction
location.
Look-up table data may be stored two bytes per
program word while programming. The Table Pointer
(TBLPTR) specifies the byte address and the Table
Latch (TABLAT) contains the data that is read from the
program memory. Data is transferred from program
memory one byte at a time.
Table read operation is discussed further in
Section 6.1 “Table Reads and Table Writes”.
CALL SUB1, FAST ;STATUS, WREG, BSR
;SAVED IN FAST REGISTER
;STACK
SUB1
RETURN FAST ;RESTORE VALUES SAVED
;IN FAST REGISTER STACK
MOVF OFFSET, W
CALL TABLE
ORG nn00h
TABLE ADDWF PCL
RETLW nnh
RETLW nnh
RETLW nnh
.
.
.
PIC18F87J11 FAMILY
DS39778C-page 68 Preliminary © 2008 Microchip Technology Inc.
5.2 PIC18 Instruction Cycle
5.2.1 CLOCKING SCHEME
The microcontroller clock input, whether from an
internal or external source, is internally divided by four
to generate four non-overlapping quadrature clocks
(Q1, Q2, Q3 and Q4). Internally, the program counter is
incremented on every Q1; the instruction is fetched
from the program memory and latched into the Instruc-
tion Register (IR) during Q4. The instruction is decoded
and executed during the following Q1 through Q4. The
clocks and instruction execution flow are shown in
Figure 5-5.
5.2.2 INSTRUCTION FLOW/PIPELINING
An “Instruction Cycle” consists of four Q cycles, Q1
through Q4. The instruction fetch and execute are pipe-
lined in such a manner that a fetch takes one instruction
cycle, while the decode and execute takes another
instruction cycle. However, due to the pipelining, each
instruction effectively executes in one cycle. If an
instruction causes the program counter to change (e.g.,
GOTO), then two cycles are required to complete the
instruction (Example 5-3).
A fetch cycle begins with the Program Counter (PC)
incrementing in Q1.
In the execution cycle, the fetched instruction is latched
into the Instruction Register (IR) in cycle Q1. This
instruction is then decoded and executed during the
Q2, Q3 and Q4 cycles. Data memory is read during Q2
(operand read) and written during Q4 (destination
write).
FIGURE 5-5: CLOCK/INSTRUCTION CYCLE
EXAMPLE 5-3: INSTRUCTION PIPELINE FLOW
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
Q1
Q2
Q3
Q4
PC
OSC2/CLKO
(RC mode)
PC PC + 2 PC + 4
Fetch INST (PC)
Execute INST (PC – 2)
Fetch INST (PC + 2)
Execute INST (PC)
Fetch INST (PC + 4)
Execute INST (PC + 2)
Internal
Phase
Clock
All instructions are single cycle, except for any program branches. These take two cycles since the fetch instruction
is “flushed” from the pipeline while the new instruction is being fetched and then executed.
TCY0TCY1TCY2TCY3TCY4TCY5
1. MOVLW 55h Fetch 1 Execute 1
2. MOVWF PORTB Fetch 2 Execute 2
3. BRA SUB_1 Fetch 3 Execute 3
4. BSF PORTA, BIT3 (Forced NOP) Fetch 4 Flush (NOP)
5. Instruction @ address SUB_1 Fetch SUB_1 Execute SUB_1
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 69
PIC18F87J11 FAMILY
5.2.3 INSTRUCTIONS IN PROGRAM
MEMORY
The program memory is addressed in bytes. Instruc-
tions are stored as two bytes or four bytes in program
memory. The Least Significant Byte of an instruction
word is always stored in a program memory location
with an even address (LSB = 0). To maintain alignment
with instruction boundaries, the PC increments in steps
of 2 and the LSB will always read ‘0’ (see Section 5.1.5
“Program Counter”).
Figure 5-6 shows an example of how instruction words
are stored in the program memory.
The CALL and GOTO instructions have the absolute
program memory address embedded into the instruc-
tion. Since instructions are always stored on word
boundaries, the data contained in the instruction is a
word address. The word address is written to PC<20:1>
which accesses the desired byte address in program
memory. Instruction #2 in Figure 5-6 shows how the
instruction, GOTO 0006h, is encoded in the program
memory. Program branch instructions, which encode a
relative address offset, operate in the same manner. The
offset value stored in a branch instruction represents the
number of single-word instructions that the PC will be
offset by. Section 25.0 “Instruction Set Summary”
provides further details of the instruction set.
FIGURE 5-6: INSTRUCTIONS IN PROGRAM MEMORY
5.2.4 TWO-WORD INSTRUCTIONS
The standard PIC18 instruction set has four two-word
instructions: CALL, MOVFF, GOTO and LSFR. In all
cases, the second word of the instructions always has
1111’ as its four Most Significant bits; the other 12 bits
are literal data, usually a data memory address.
The use of1111’ in the 4 MSbs of an instruction
specifies a special form of NOP. If the instruction is
executed in proper sequence – immediately after the
first word – the data in the second word is accessed
and used by the instruction sequence. If the first word
is skipped for some reason and the second word is
executed by itself, a NOP is executed instead. This is
necessary for cases when the two-word instruction is
preceded by a conditional instruction that changes the
PC. Example 5-4 shows how this works.
EXAMPLE 5-4: TWO-WORD INSTRUCTIONS
Word Address
LSB = 1LSB = 0
Program Memory
Byte Locations
000000h
000002h
000004h
000006h
Instruction 1: MOVLW 055h 0Fh 55h 000008h
Instruction 2: GOTO 0006h EFh 03h 00000Ah
F0h 00h 00000Ch
Instruction 3: MOVFF 123h, 456h C1h 23h 00000Eh
F4h 56h 000010h
000012h
000014h
Note: See Section 5.5 “Program Memory and
the Extended Instruction Set” for
information on two-word instructions in the
extended instruction set.
CASE 1:
Object Code Source Code
0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0?
1100 0001 0010 0011 MOVFF REG1, REG2 ; No, skip this word
1111 0100 0101 0110 ; Execute this word as a NOP
0010 0100 0000 0000 ADDWF REG3 ; continue code
CASE 2:
Object Code Source Code
0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0?
1100 0001 0010 0011 MOVFF REG1, REG2 ; Yes, execute this word
1111 0100 0101 0110 ; 2nd word of instruction
0010 0100 0000 0000 ADDWF REG3 ; continue code
PIC18F87J11 FAMILY
DS39778C-page 70 Preliminary © 2008 Microchip Technology Inc.
5.3 Data Memory Organization
The data memory in PIC18 devices is implemented as
static RAM. Each register in the data memory has a
12-bit address, allowing up to 4096 bytes of data
memory. The memory space is divided into as many as
16 banks that contain 256 bytes each. The
PIC18F87J11 family implements all available banks
and provide 3936 bytes of data memory available to the
user. Figure 5-7 shows the data memory organization
for the devices.
The data memory contains Special Function Registers
(SFRs) and General Purpose Registers (GPRs). The
SFRs are used for control and status of the controller
and peripheral functions, while GPRs are used for data
storage and scratchpad operations in the user’s
application. Any read of an unimplemented location will
read as ‘0’s.
The instruction set and architecture allow operations
across all banks. The entire data memory may be
accessed by Direct, Indirect or Indexed Addressing
modes. Addressing modes are discussed later in this
section.
To ensure that commonly used registers (select SFRs
and select GPRs) can be accessed in a single cycle,
PIC18 devices implement an Access Bank. This is a
256-byte memory space that provides fast access to
select SFRs and the lower portion of GPR Bank 0 with-
out using the BSR. Section 5.3.2 “Access Bank”
provides a detailed description of the Access RAM.
5.3.1 BANK SELECT REGISTER
Large areas of data memory require an efficient
addressing scheme to make rapid access to any
address possible. Ideally, this means that an entire
address does not need to be provided for each read or
write operation. For PIC18 devices, this is accom-
plished with a RAM banking scheme. This divides the
memory space into 16 contiguous banks of 256 bytes.
Depending on the instruction, each location can be
addressed directly by its full 12-bit address, or an 8-bit
low-order address and a 4-bit Bank Pointer.
Most instructions in the PIC18 instruction set make use
of the Bank Pointer, known as the Bank Select Register
(BSR). This SFR holds the 4 Most Significant bits of a
location’s address; the instruction itself includes the
8 Least Significant bits. Only the four lower bits of the
BSR are implemented (BSR3:BSR0). The upper four
bits are unused; they will always read ‘0’ and cannot be
written to. The BSR can be loaded directly by using the
MOVLB instruction.
The value of the BSR indicates the bank in data mem-
ory. The 8 bits in the instruction show the location in the
bank and can be thought of as an offset from the bank’s
lower boundary. The relationship between the BSR’s
value and the bank division in data memory is shown in
Figure 5-8.
Since up to 16 registers may share the same low-order
address, the user must always be careful to ensure that
the proper bank is selected before performing a data
read or write. For example, writing what should be
program data to an 8-bit address of F9h while the BSR
is 0Fh, will end up resetting the program counter.
While any bank can be selected, only those banks that
are actually implemented can be read or written to.
Writes to unimplemented banks are ignored, while
reads from unimplemented banks will return ‘0’s. Even
so, the STATUS register will still be affected as if the
operation was successful. The data memory map in
Figure 5-7 indicates which banks are implemented.
In the core PIC18 instruction set, only the MOVFF
instruction fully specifies the 12-bit address of the
source and target registers. This instruction ignores the
BSR completely when it executes. All other instructions
include only the low-order address as an operand and
must use either the BSR or the Access Bank to locate
their target registers.
Note: The operation of some aspects of data
memory are changed when the PIC18
extended instruction set is enabled. See
Section 5.6 “Data Memory and the
Extended Instruction Set” for more
information.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 71
PIC18F87J11 FAMILY
FIGURE 5-7: DATA MEMORY MAP FOR PIC18F87J11 FAMILY DEVICES
Bank 0
Bank 1
Bank 14
Bank 15
Data Memory Map
BSR<3:0>
= 0000
= 0001
= 1111
060h
05Fh
F60h
FFFh
00h
5Fh
60h
FFh
Access Bank
When a = 0:
The BSR is ignored and the
Access Bank is used.
The first 96 bytes are general
purpose RAM (from Bank 0).
The remaining 160 bytes are
Special Function Registers
(from Bank 15).
When a = 1:
The BSR specifies the bank
used by the instruction.
F5Fh
F00h
EFFh
1FFh
100h
0FFh
000h
Access RAM
FFh
00h
FFh
00h
FFh
00h
GPR
GPR
SFR
Access RAM High
Access RAM Low
Bank 2
= 0010
(SFRs)
2FFh
200h
Bank 3
FFh
00h
GPR
FFh
= 0011
= 1101
GPR(1)
GPR
GPR
GPR
GPR
GPR
GPR
GPR
GPR
GPR
GPR
4FFh
400h
5FFh
500h
3FFh
300h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
00h
GPR
GPR
= 0110
= 0111
= 1010
= 1100
= 1000
= 0101
= 1001
= 1011
= 0100 Bank 4
Bank 5
Bank 6
Bank 7
Bank 8
Bank 9
Bank 10
Bank 11
Bank 12
Bank 13
= 1110
6FFh
600h
7FFh
700h
8FFh
800h
9FFh
900h
AFFh
A00h
BFFh
B00h
CFFh
C00h
DFFh
D00h
E00h
Note 1: Addresses F5Ah through F5Fh are also used by SFRs, but are not part of the Access RAM. Users must always
use the complete address, or load the proper BSR value, to access these registers.
PIC18F87J11 FAMILY
DS39778C-page 72 Preliminary © 2008 Microchip Technology Inc.
FIGURE 5-8: USE OF THE BANK SELECT REGISTER (DIRECT ADDRESSING)
5.3.2 ACCESS BANK
While the use of the BSR with an embedded 8-bit
address allows users to address the entire range of
data memory, it also means that the user must always
ensure that the correct bank is selected. Otherwise,
data may be read from or written to the wrong location.
This can be disastrous if a GPR is the intended target
of an operation, but an SFR is written to instead.
Verifying and/or changing the BSR for each read or
write to data memory can become very inefficient.
To streamline access for the most commonly used data
memory locations, the data memory is configured with
an Access Bank, which allows users to access a
mapped block of memory without specifying a BSR.
The Access Bank consists of the first 96 bytes of
memory (00h-5Fh) in Bank 0 and the last 160 bytes of
memory (60h-FFh) in Bank 15. The lower half is known
as the “Access RAM” and is composed of GPRs. The
upper half is where the device’s SFRs are mapped.
These two areas are mapped contiguously in the
Access Bank and can be addressed in a linear fashion
by an 8-bit address (Figure 5-7).
The Access Bank is used by core PIC18 instructions
that include the Access RAM bit (the ‘a’ parameter in
the instruction). When ‘a’ is equal to ‘1’, the instruction
uses the BSR and the 8-bit address included in the
opcode for the data memory address. When ‘a’ is ‘0’,
however, the instruction is forced to use the Access
Bank address map; the current value of the BSR is
ignored entirely.
Using this “forced” addressing allows the instruction to
operate on a data address in a single cycle without
updating the BSR first. For 8-bit addresses of 60h and
above, this means that users can evaluate and operate
on SFRs more efficiently. The Access RAM below 60h
is a good place for data values that the user might need
to access rapidly, such as immediate computational
results or common program variables. Access RAM
also allows for faster and more code efficient context
saving and switching of variables.
The mapping of the Access Bank is slightly different
when the extended instruction set is enabled (XINST
Configuration bit = 1). This is discussed in more detail
in Section 5.6.3 “Mapping the Access Bank in
Indexed Literal Offset Mode”.
5.3.3 GENERAL PURPOSE
REGISTER FILE
PIC18 devices may have banked memory in the GPR
area. This is data RAM which is available for use by all
instructions. GPRs start at the bottom of Bank 0
(address 000h) and grow upwards towards the bottom
of the SFR area. GPRs are not initialized by a
Power-on Reset and are unchanged on all other
Resets.
Note 1: The Access RAM bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to
the registers of the Access Bank.
2: The MOVFF instruction embeds the entire 12-bit address in the instruction.
Data Memory
Bank Select(2)
70
From Opcode(2)
0000
000h
100h
200h
300h
F00h
E00h
FFFh
Bank 0
Bank 1
Bank 2
Bank 14
Bank 15
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
Bank 3
through
Bank 13
0010 11111 111
70
BSR(1)
11111111
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 73
PIC18F87J11 FAMILY
5.3.4 SPECIAL FUNCTION REGISTERS
The Special Function Registers (SFRs) are registers
used by the CPU and peripheral modules for controlling
the desired operation of the device. These registers are
implemented as static RAM. SFRs start at the top of
data memory (FFFh) and extend downward to occupy
more than the top half of Bank 15 (F5Ah to FFFh). A list
of these registers is given inTable 5-3, Table 5-4 and
Table 5-5.
The SFRs can be classified into two sets: those
associated with the “core” device functionality (ALU,
Resets and interrupts) and those related to the
peripheral functions. The Reset and interrupt registers
are described in their respective chapters, while the
ALU’s STATUS register is described later in this
section. Registers related to the operation of the
peripheral features are described in the chapter for that
peripheral.
The SFRs are typically distributed among the
peripherals whose functions they control. Unused SFR
locations are unimplemented and read as 0’s
Note: Addresses, F5Ah through F5Fh, are not
part of the Access Bank. These registers
must always be accessed using the Bank
Select Register.
TABLE 5-3: SPECIAL FUNCTION REGISTER MAP FOR PIC18F87J11 FAMILY DEVICES
Address Name Address Name Address Name Address Name Address Name Address Name
FFFh TOSU FDFh INDF2
(1)
FBFh ECCP1AS F9Fh IPR1 F7Fh SPBRGH1 F5Fh PMDIN2H
FFEh TOSH FDEh POSTINC2
(1)
FBEh ECCP1DEL F9Eh PIR1 F7Eh BAUDCON1 F5Eh PMDIN2L
FFDh TOSL FDDh POSTDEC2
(1)
FBDh CCPR1H F9Dh PIE1 F7Dh SPBRGH2 F5Dh PMEH
FFCh STKPTR FDCh PREINC2
(1)
FBCh CCPR1L F9Ch RCSTA2 F7Ch BAUDCON2 F5Ch PMEL
FFBh PCLATU FDBh PLUSW2
(1)
FBBh CCP1CON F9Bh OSCTUNE F7Bh TMR3H F5Bh PMSTATH
FFAh PCLATH FDAh FSR2H FBAh ECCP2AS F9Ah TRISJ
(2)
F7Ah TMR3L F5Ah PMSTATL
FF9h PCL FD9h FSR2L FB9h ECCP2DEL F99h TRISH
(2)
F79h T3CON F59h
FF8h TBLPTRU FD8h STATUS FB8h CCPR2H F98h TRISG F78h TMR4 F58h
FF7h TBLPTRH FD7h TMR0H FB7h CCPR2L F97h TRISF F77h PR4
(3)
F57h
FF6h TBLPTRL FD6h TMR0L FB6h CCP2CON F96h TRISE F76h T4CON F56h
FF5h TABLAT FD5h T0CON FB5h ECCP3AS F95h TRISD F75h CCPR4H F55h
FF4h PRODH FD4h FB4h ECCP3DEL F94h TRISC F74h CCPR4L F54h
FF3h PRODL FD3h OSCCON
(3)
FB3h CCPR3H F93h TRISB F73h CCP4CON F53h
FF2h INTCON FD2h CM1CON FB2h CCPR3L F92h TRISA F72h CCPR5H F52h
FF1h INTCON2 FD1h CM2CON FB1h CCP3CON F91h LATJ
(2)
F71h CCPR5L F51h
FF0h INTCON3 FD0h RCON FB0h SPBRG1 F90h LATH
(2)
F70h CCP5CON F50h
FEFh INDF0
(1)
FCFh TMR1H
(3)
FAFh RCREG1 F8Fh LATG F6Fh SSP2BUF F4Fh
FEEh POSTINC0
(1)
FCEh TMR1L
(3)
FAEh TXREG1 F8Eh LATF F6Eh SSP2ADD F4Eh
FEDh POSTDEC0
(1)
FCDh T1CON
(3)
FADh TXSTA1 F8Dh LATE F6Dh SSP2STAT F4Dh
FECh PREINC0
(1)
FCCh TMR2
(3)
FACh RCSTA1 F8Ch LATD F6Ch SSP2CON1 F4Ch
FEBh PLUSW0
(1)
FCBh PR2
(3)
FABh SPBRG2 F8Bh LATC F6Bh SSP2CON2 F4Bh
FEAh FSR0H FCAh T2CON FAAh RCREG2 F8Ah LATB F6Ah CMSTAT F4Ah
FE9h FSR0L FC9h SSP1BUF FA9h TXREG2 F89h LATA F69h PMADDRH
(4)
F49h
FE8h WREG FC8h SSP1ADD FA8h TXSTA2 F88h PORTJ
(2)
F68h PMADDRL
(4)
F48h
FE7h INDF1
(1)
FC7h SSP1STAT FA7h EECON2 F87h PORTH
(2)
F67h PMDIN1H F47h
FE6h POSTINC1
(1)
FC6h SSP1CON1 FA6h EECON1 F86h PORTG F66h PMDIN1L F46h
FE5h POSTDEC1
(1)
FC5h SSP1CON2 FA5h IPR3 F85h PORTF F65h PMCONH F45h
FE4h PREINC1
(1)
FC4h ADRESH FA4h PIR3 F84h PORTE F64h PMCONL F44h
FE3h PLUSW1
(1)
FC3h ADRESL FA3h PIE3 F83h PORTD F63h PMMODEH F43h
FE2h FSR1H FC2h ADCON0
(3)
FA2h IPR2 F82h PORTC F62h PMMODEL F42h
FE1h FSR1L FC1h ADCON1
(3)
FA1h PIR2 F81h PORTB F61h PMDOUT2H F41h
FE0h BSR FC0h WDTCON FA0h PIE2 F80h PORTA F60h PMDOUT2L F40h
Note 1: This is not a physical register.
2: This register is not available on 64-pin devices.
3: This register shares the same address with another register (see Table 5-4 for alternate register).
4: The PMADDRH/L and PMDOUT1H/L register pairs share the same address. PMADDR is used in Master modes and PMDOUT1 is used
in Slave modes.
PIC18F87J11 FAMILY
DS39778C-page 74 Preliminary © 2008 Microchip Technology Inc.
5.3.4.1 Shared Address SFRs
In several locations in the SFR bank, a single address
is used to access two different hardware registers. In
these cases, a “legacy” register of the standard PIC18
SFR set (such as OSCCON, T1CON, etc.) shares its
address with an alternate register. These alternate reg-
isters are associated with enhanced configuration
options for peripherals, or with new device features not
included in the standard PIC18 SFR map. A complete
list of shared register addresses and the registers
associated with them is provided in Table 5-4.
Access to the alternate registers is enabled in software
by setting the ADSHR bit in the WDTCON register
(Register 5-3). ADSHR must be manually set or
cleared to access the alternate or legacy registers, as
required. Since the bit remains in a given state until
changed, users should always verify the state of
ADSHR before writing to any of the shared SFR
addresses.
5.3.4.2 Context Defined SFRs
In addition to the shared address SFRs, there are
several registers that share the same address in the
SFR space, but are not accessed with the ADSHR bit.
Instead, the register’s definition and use depends on
the operating mode of its associated peripheral. These
registers are:
SSPxADD and SSPxMSK: These are two
separate hardware registers, accessed through a
single SFR address. The operating mode of the
MSSP module determines which register is being
accessed. See Section 19.4.3.4 “7-Bit Address
Masking Mode” for additional details.
PMADDRH/L and PMDOUT2H/L: In this case,
these named buffer pairs are actually the same
physical registers. The PMP module’s operating
mode determines what function the registers take
on. See Section 11.1.2 “Data Registers” for
additional details.
TABLE 5-4: SHARED SFR ADDRESSES FOR PIC18F87J11 FAMILY DEVICES
Address Name Address Name Address Name
FD3h (D) OSCCON
FCDh
(D) T1CON FC2h (D) ADCON0
(A) REFOCON (A) ODCON3 (A) ANCON1
FCFh (D) TMR1H
FCCh
(D) TMR2 FC1h (D) ADCON1
(A) ODCON1 (A) PADCFG1 (A) ANCON0
FCEh (D) TMR1L
FCBh
(D) PR2 F77h (D) PR4
(A) ODCON2 (A) MEMCON(1) (A) CVRCON
Legend: (D) = Default SFR, accessible only when ADSHR = 0; (A) = Alternate SFR, accessible only when ADSHR = 1.
Note 1: Implemented in 80-pin devices only.
REGISTER 5-3: WDTCON: WATCHDOG TIMER CONTROL REGISTER
R/W-0 R-x U-0 R/W-0 U-0 U-0 U-0 U-0
REGSLP LVDSTAT ADSHR —SWDTEN
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 REGSLP: Voltage Regulator Low-Power Operation Enable bit
For details of bit operation, see Register 24-9.
bit 6 LVDSTAT: LVD Status bit
1 = VDDCORE > 2.45V
0 = VDDCORE < 2.45V
bit 5 Unimplemented: Read as ‘0
bit 4 ADSHR: Shared Address SFR Select bit
1 = Alternate SFR is selected
0 = Default (Legacy) SFR is selected
bit 3-1 Unimplemented: Read as ‘0
bit 0 SWDTEN: Software Controlled Watchdog Timer Enable bit
For details of bit operation, see Register 24-9.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 75
PIC18F87J11 FAMILY
TABLE 5-5: REGISTER FILE SUMMARY (PIC18F87J11 FAMILY)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Details
on
Page:
TOSU Top-of-Stack Upper Byte (TOS<20:16>) ---0 0000 55, 65
TOSH Top-of-Stack High Byte (TOS<15:8>) 0000 0000 55, 65
TOSL Top-of-Stack Low Byte (TOS<7:0>) 0000 0000 55, 65
STKPTR STKFUL STKUNF SP4 SP3 SP2 SP1 SP0 00-0 0000 55, 66
PCLATU —bit 21
(1) Holding Register for PC<20:16> ---0 0000 55, 65
PCLATH Holding Register for PC<15:8> 0000 0000 55, 65
PCL PC Low Byte (PC<7:0>) 0000 0000 55, 65
TBLPTRU bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) --00 0000 55, 96
TBLPTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 55, 96
TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 0000 0000 55, 96
TABLAT Program Memory Table Latch 0000 0000 55, 96
PRODH Product Register High Byte xxxx xxxx 55, 109
PRODL Product Register Low Byte xxxx xxxx 55, 109
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 55, 113
INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP 1111 1111 55, 113
INTCON3 INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF 1100 0000 55, 113
INDF0 Uses contents of FSR0 to address data memory – value of FSR0 not changed (not a physical register) N/A 55, 82
POSTINC0 Uses contents of FSR0 to address data memory – value of FSR0 post-incremented (not a physical register) N/A 55, 83
POSTDEC0 Uses contents of FSR0 to address data memory – value of FSR0 post-decremented (not a physical register) N/A 55, 83
PREINC0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) N/A 55, 83
PLUSW0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) –
value of FSR0 offset by W
N/A 55, 83
FSR0H Indirect Data Memory Address Pointer 0 High Byte ---- xxxx 55, 82
FSR0L Indirect Data Memory Address Pointer 0 Low Byte xxxx xxxx 55, 82
WREG Working Register xxxx xxxx 55, 67
INDF1 Uses contents of FSR1 to address data memory – value of FSR1 not changed (not a physical register) N/A 55, 82
POSTINC1 Uses contents of FSR1 to address data memory – value of FSR1 post-incremented (not a physical register) N/A 55, 83
POSTDEC1 Uses contents of FSR1 to address data memory – value of FSR1 post-decremented (not a physical register) N/A 55, 83
PREINC1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) N/A 55, 83
PLUSW1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) –
value of FSR1 offset by W
N/A 55, 83
FSR1H Indirect Data Memory Address Pointer 1 High Byte ---- xxxx 55, 82
FSR1L Indirect Data Memory Address Pointer 1 Low Byte xxxx xxxx 55, 82
BSR Bank Select Register ---- 0000 55, 70
INDF2 Uses contents of FSR2 to address data memory – value of FSR2 not changed (not a physical register) N/A 56, 82
POSTINC2 Uses contents of FSR2 to address data memory – value of FSR2 post-incremented (not a physical register) N/A 56, 83
POSTDEC2 Uses contents of FSR2 to address data memory – value of FSR2 post-decremented (not a physical register) N/A 56, 83
PREINC2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) N/A 56, 83
PLUSW2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) –
value of FSR2 offset by W
N/A 56, 83
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming modes.
2: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
3: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
4: Reset value is ‘0 when Two-Speed Start-up is enabled and1’ if disabled.
5: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
6: Alternate names and definitions for these bits when the MSSP modules are operating in I2C™ Slave mode. See Section 19.4.3.2
“Address Masking Modes” for details
7: These bits and/or registers are only available in 80-pin devices; otherwise, they are unimplemented and read as ‘0’. Reset values are
shown for 80-pin devices.
8:
These bits are only available in select oscillator modes (FOSC2 Configuration bit =
0
); otherwise, they are unimplemented.
9: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the physical registers and addresses, but have different
functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
PIC18F87J11 FAMILY
DS39778C-page 76 Preliminary © 2008 Microchip Technology Inc.
FSR2H Indirect Data Memory Address Pointer 2 High Byte ---- xxxx 56, 82
FSR2L Indirect Data Memory Address Pointer 2 Low Byte xxxx xxxx 56, 82
STATUS —NOVZDCC---x xxxx 56, 80
TMR0H Timer0 Register High Byte 0000 0000 56, 179
TMR0L Timer0 Register Low Byte xxxx xxxx 56, 179
T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 56, 178
OSCCON(2)/IDLEN IRCF2 IRCF1 IRCF0 OSTS(4) SCS1 SCS0 0110 q100 56, 32
REFOCON(3) ROON ROSSLP ROSEL RODIV3 RODIV2 RODIV1 RODIV0 0-00 0000 56, 39
CM1CON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 0001 1111 56, 302
CM2CON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 0001 1111 56, 302
RCON IPEN —CMRI TO PD POR BOR 0-11 1100 54, 56,
125
TMR1H(2)/Timer1 Register High Byte xxxx xxxx 56, 182
ODCON1(3) CCP5OD CCP4OD ECCP3OD ECCP2OD ECCP1OD ---0 0000 56, 129
TMR1L(2)/Timer1 Register Low Byte xxxx xxxx 56, 182
ODCON2(3) ———— U2OD U1OD ---- --00 56, 129
T1CON (2)/RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0000 0000 56, 182
ODCON3(3) ———— SPI2OD SPI1OD ---- --00 56, 129
TMR2(2)/Timer2 Register 0000 0000 56, 187
PADCFG1(3) ——————PMPTTL---- ---0 56, 130
PR2(2)/Timer2 Period Register 1111 1111 56, 187
MEMCON(3,7) EDBIS —WAIT1WAIT0—WM1WM00-00 --00 56, 98
T2CON T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 56, 187
SSP1BUF MSSP1 Receive Buffer/Transmit Register xxxx xxxx 56, 222,
231
SSP1ADD/ MSSP1 Address Register (I2C™ Slave mode), MSSP1 Baud Rate Reload Register (I2C Master mode) 0000 0000 56, 231
SSP1MSK(5) MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0 0000 0000 56, 238
SSP1STAT SMP CKE D/A PSR/WUA BF 0000 0000 56, 222,
232
SSP1CON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 56, 223,
233
SSP1CON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN/ SEN 0000 0000 56, 234,
268
GCEN ACKSTAT ADMSK5
(6)
ADMSK4
(6)
ADMSK3
(6)
ADMSK2
(6)
ADMSK1
(6)
SEN
ADRESH A/D Result Register High Byte xxxx xxxx 57, 291
ADRESL A/D Result Register Low Byte xxxx xxxx 57, 291
ADCON0(2)/VCFG1 VCFG0 CHS3 CHS2 CHS1 CHS0 GO/DONE ADON 0000 0000 57, 291
ANCON1(3) PCFG15 PCFG14 PCFG13 PCFG12 PCFG11 PCFG10 PCFG9 PCFG8 0000 0000 57, 293
ADCON1(2)/ ADFM ADCAL ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 0000 0000 57, 292
ANCON0(3) PCFG7 PCFG6 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 00-0 0000 57, 293
WDTCON REGSLP LVDSTAT —ADSHR———SWDTEN0x-0 ---0 57, 321
TABLE 5-5: REGISTER FILE SUMMARY (PIC18F87J11 FAMILY) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Details
on
Page:
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming modes.
2: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
3: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
4: Reset value is ‘0 when Two-Speed Start-up is enabled and1’ if disabled.
5: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
6: Alternate names and definitions for these bits when the MSSP modules are operating in I2C™ Slave mode. See Section 19.4.3.2
“Address Masking Modes” for details
7: These bits and/or registers are only available in 80-pin devices; otherwise, they are unimplemented and read as ‘0’. Reset values are
shown for 80-pin devices.
8:
These bits are only available in select oscillator modes (FOSC2 Configuration bit =
0
); otherwise, they are unimplemented.
9: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the physical registers and addresses, but have different
functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 77
PIC18F87J11 FAMILY
ECCP1AS ECCP1ASE ECCP1AS2 ECCP1AS1 ECCP1AS0 PSS1AC1 PSS1AC0 PSS1BD1 PSS1BD0 0000 0000 57, 219
ECCP1DEL P1RSEN P1DC6 P1DC5 P1DC4 P1DC3 P1DC2 P1DC1 P1DC0 0000 0000 57, 219
CCPR1H Capture/Compare/PWM Register 1 HIgh Byte xxxx xxxx 57, 219
CCPR1L Capture/Compare/PWM Register 1 Low Byte xxxx xxxx 57, 219
CCP1CON P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 0000 0000 57, 219
ECCP2AS ECCP2ASE ECCP2AS2 ECCP2AS1 ECCP2AS0 PSS2AC1 PSS2AC0 PSS2BD1 PSS2BD0 0000 0000 57, 219
ECCP2DEL P2RSEN P2DC6 P2DC5 P2DC4 P2DC3 P2DC2 P2DC1 P2DC0 0000 0000 57, 219
CCPR2H Capture/Compare/PWM Register 2 High Byte xxxx xxxx 57, 219
CCPR2L Capture/Compare/PWM Register 2 Low Byte xxxx xxxx 57, 219
CCP2CON P2M1 P2M0 DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 0000 0000 57, 219
ECCP3AS ECCP3ASE ECCP3AS2 ECCP3AS1 ECCP3AS0 PSS3AC1 PSS3AC0 PSS3BD1 PSS3BD0 0000 0000 57, 219
ECCP3DEL P3RSEN P3DC6 P3DC5 P3DC4 P3DC3 P3DC2 P3DC1 P3DC0 0000 0000 57, 219
CCPR3H Capture/Compare/PWM Register 1 High Byte xxxx xxxx 57, 219
CCPR3L Capture/Compare/PWM Register 1 Low Byte xxxx xxxx 57, 219
CCP3CON P3M1 P3M0 DC3B1 DC3B0 CCP3M3 CCP3M2 CCP3M1 CCP3M0 0000 0000 57, 219
SPBRG1 EUSART1 Baud Rate Generator Register Low Byte 0000 0000 57, 273
RCREG1 EUSART1 Receive Register 0000 0000 57, 281,
282
TXREG1 EUSART1 Transmit Register xxxx xxxx 57, 279,
280
TXSTA1 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 57, 279
RCSTA1 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 57, 281
SPBRG2 EUSART2 Baud Rate Generator Register Low Byte 0000 0000 57, 273
RCREG2 EUSART2 Receive Register 0000 0000 57, 281,
282
TXREG2 EUSART2 Transmit Register 0000 0000 57, 279,
280
TXSTA2 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 57, 279
EECON2 Program Memory Control Register 2 (not a physical register) ---- ---- 57, 88
EECON1 WPROG FREE WRERR WREN WR --00 x00- 57, 88
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 1111 1111 58, 122
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 0000 0000 58, 116
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 0000 0000 58, 119
IPR2 OSCFIP CM2IP CM1IP BCL1IP LVDIP TMR3IP CCP2IP 111- 1111 58, 122
PIR2 OSCFIF CM2IF CM1IF BCL1IF LVDIF TMR3IF CCP2IF 000- 0000 58, 116
PIE2 OSCFIE CM2IE CM1IE BCL1IE LVDIE TMR3IE CCP2IE 000- 0000 58, 119
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 1111 1111 58, 122
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 0000 0000 58, 116
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 0000 0000 58, 119
RCSTA2 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 58, 281
OSCTUNE INTSRC PLLEN TUN5 TUN4 TUN3 TUN2 TUN1 TUN0 0000 0000 58, 33
TABLE 5-5: REGISTER FILE SUMMARY (PIC18F87J11 FAMILY) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Details
on
Page:
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming modes.
2: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
3: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
4: Reset value is ‘0 when Two-Speed Start-up is enabled and1’ if disabled.
5: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
6: Alternate names and definitions for these bits when the MSSP modules are operating in I2C™ Slave mode. See Section 19.4.3.2
“Address Masking Modes” for details
7: These bits and/or registers are only available in 80-pin devices; otherwise, they are unimplemented and read as ‘0’. Reset values are
shown for 80-pin devices.
8:
These bits are only available in select oscillator modes (FOSC2 Configuration bit =
0
); otherwise, they are unimplemented.
9: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the physical registers and addresses, but have different
functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
PIC18F87J11 FAMILY
DS39778C-page 78 Preliminary © 2008 Microchip Technology Inc.
TRISJ(7) TRISJ7 TRISJ6 TRISJ5 TRISJ4 TRISJ3 TRISJ2 TRISJ1 TRISJ0 1111 1111 58, 150
TRISH(7) TRISH7 TRISH6 TRISH5 TRISH4 TRISH3 TRISH2 TRISH1 TRISH0 1111 1111 58, 148
TRISG TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 ---1 1111 58, 146
TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 1111 111- 58, 144
TRISE TRISE7 TRISE6 TRISE5 TRISE4 TRISE3 TRISE2 TRISE1 TRISE0 1111 1111 58, 141
TRISD TRISD7 TRISD6 TRISD5 TRISD4 TRISD3 TRISD2 TRISD1 TRISD0 1111 1111 58, 138
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 1111 1111 58, 136
TRISB TRISB7 TRISB6 TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 1111 1111 58, 134
TRISA TRISA7(8) TRISA6(8) TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 1111 1111 58, 132
LATJ(7) LATJ7 LATJ6 LATJ5 LATJ4 LATJ3 LATJ2 LATJ1 LATJ0 xxxx xxxx 58, 150
LATH(7) LATH7 LATH6 LATH5 LATH4 LATH3 LATH2 LATH1 LATH0 xxxx xxxx 58, 148
LATG LATG4 LATG3 LATG2 LATG1 LATG0 ---x xxxx 58, 146
LATF LATF7 LATF6 LATF5 LATF4 LATF3 LATF2 LATF1 xxxx xxx- 58, 144
LATE LATE7 LATE6 LATE5 LATE4 LATE3 LATE2 LATE1 LATE0 xxxx xxxx 58, 141
LATD LATD7 LATD6 LATD5 LATD4 LATD3 LATD2 LATD1 LATD0 xxxx xxxx 58, 138
LATC LATC7 LATC6 LATC5 LATC4 LATC3 LATC2 LATC1 LATC0 xxxx xxxx 58, 136
LATB LATB7 LATB6 LATB5 LATB4 LATB3 LATB2 LATB1 LATB0 xxxx xxxx 58, 134
LATA LATA7(8) LATA6(8) LATA5 LATA4 LATA3 LATA2 LATA1 LATA0 xxxx xxxx 58, 132
PORTJ(7) RJ7 RJ6 RJ5 RJ4 RJ3 RJ2 RJ1 RJ0 xxxx xxxx 59, 150
PORTH(7) RH7 RH6 RH5 RH4 RH3 RH2 RH1 RH0 0000 xxxx 59, 148
PORTG RDPU REPU RJPU(7) RG4 RG3 RG2 RG1 RG0 000x xxxx 59, 146
PORTF RF7 RF6 RF5 RF4 RF3 RF2 RF1 x000 000- 59, 144
PORTE RE7 RE6 RE5 RE4 RE3 RE2 RE1 RE0 xxxx xxxx 59, 141
PORTD RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 xxxx xxxx 59, 138
PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 xxxx xxxx 59, 136
PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xxxx xxxx 59, 134
PORTA RA7(8) RA6(8) RA5 RA4 RA3 RA2 RA1 RA0 000x 0000 59, 132
SPBRGH1 EUSART1 Baud Rate Generator Register High Byte 0000 0000 59, 273
BAUDCON1 ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 0100 0-00 59, 273
SPBRGH2 EUSART2 Baud Rate Generator Register High Byte 0000 0000 59, 273
BAUDCON2 ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 0100 0-00 59, 273
TMR3H Timer3 Register High Byte xxxx xxxx 59, 194
TMR3L Timer3 Register Low Byte xxxx xxxx 59, 194
T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 0000 0000 59, 194
TMR4 Timer4 Register 0000 0000 59, 193
PR4(2)/Timer4 Period Register 1111 1111 59, 194
CVRCON
(3) CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 0000 0000 59, 310
T4CON T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0 -000 0000 59, 193
TABLE 5-5: REGISTER FILE SUMMARY (PIC18F87J11 FAMILY) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Details
on
Page:
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming modes.
2: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
3: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
4: Reset value is ‘0 when Two-Speed Start-up is enabled and1’ if disabled.
5: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
6: Alternate names and definitions for these bits when the MSSP modules are operating in I2C™ Slave mode. See Section 19.4.3.2
“Address Masking Modes” for details
7: These bits and/or registers are only available in 80-pin devices; otherwise, they are unimplemented and read as ‘0’. Reset values are
shown for 80-pin devices.
8:
These bits are only available in select oscillator modes (FOSC2 Configuration bit =
0
); otherwise, they are unimplemented.
9: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the physical registers and addresses, but have different
functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 79
PIC18F87J11 FAMILY
CCPR4H Capture/Compare/PWM Register 4 High Byte xxxx xxxx 59, 196
CCPR4L Capture/Compare/PWM Register 4 Low Byte xxxx xxxx 59, 196
CCP4CON DC4B1 DC4B0 CCP4M3 CCP4M2 CCP4M1 CCP4M0 --00 0000 59, 196
CCPR5H Capture/Compare/PWM Register 5 High Byte xxxx xxxx 59, 196
CCPR5L Capture/Compare/PWM Register 5 Low Byte xxxx xxxx 59, 196
CCP5CON DC5B1 DC5B0 CCP5M3 CCP5M2 CCP5M1 CCP5M0 --00 0000 59, 196
SSP2BUF MSSP2 Receive Buffer/Transmit Register xxxx xxxx 59, 222,
231
SSP2ADD/ MSSP2 Address Register (I2C™ Slave mode), MSSP2 Baud Rate Reload Register (I2C Master mode) 0000 0000 59, 231
SSP2MSK(5) MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0 0000 0000 59, 238
SSP2STAT SMP CKE D/A PSR/WUA BF 0000 0000 59, 222,
232
SSP2CON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 59, 223,
233
SSP2CON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN/ SEN 0000 0000 59, 234,
268
GCEN ACKSTAT ADMSK5
(6)
ADMSK4
(6)
ADMSK3
(6)
ADMSK2
(6)
ADMSK1
(6)
SEN
CMSTAT —————COUT2COUT1---- --11 59, 303
PMADDRH / CS2 CS1 Parallel Master Port Address High Byte 0000 0000 60, 158
PMDOUT1H(9) Parallel Port Out Data High Byte (Buffer 1) 0000 0000 60, 161
PMADDRL/ Parallel Master Port Address Low Byte 0000 0000 60, 158
PMDOUT1L(9) Parallel Port Out Data Low Byte (Buffer 0) 0000 0000 60, 158
PMDIN1H Parallel Port In Data High Byte (Buffer 1) 0000 0000 60, 158
PMDIN1L Parallel Port In Data Low Byte (Buffer 0) 0000 0000 60, 158
PMCONH PMPEN PSIDL ADRMUX1 ADRMUX0 PTBEEN PTWREN PTRDEN 0-00 0000 60, 152
PMCONL CSF1 CSF0 ALP CS2P CS1P BEP WRSP RDSP 0000 0000 60, 153
PMMODEH BUSY IRQM1 IRQM0 INCM1 INCM0 MODE16 MODE1 MODE0 0000 0000 60, 154
PMMODEL WAITB1 WAITB0 WAITM3 WAITM2 WAITM1 WAITM0 WAITE1 WAITE0 0000 0000 60, 155
PMDOUT2H Parallel Port Out Data High Byte (Buffer 3) 0000 0000 60, 158
PMDOUT2L Parallel Port Out Data Low Byte (Buffer 2) 0000 0000 60, 158
PMDIN2H Parallel Port In Data High Byte (Buffer 3) 0000 0000 60, 158
PMDIN2L Parallel Port In Data Low Byte (Buffer 2) 0000 0000 60, 158
PMEH PTEN15 PTEN14 PTEN13 PTEN12 PTEN11 PTEN10 PTEN9 PTEN8 0000 0000 60, 155
PMEL PTEN7 PTEN6 PTEN5 PTEN4 PTEN3 PTEN2 PTEN1 PTEN0 0000 0000 60, 156
PMSTATH IBF IBOV IB3F IB2F IB1F IB0F 00-- 0000 60, 156
PMSTATL OBE OBUF OB3E OB2E OB1E OB0E 10-- 1111 60, 157
TABLE 5-5: REGISTER FILE SUMMARY (PIC18F87J11 FAMILY) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Details
on
Page:
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming modes.
2: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
3: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
4: Reset value is ‘0 when Two-Speed Start-up is enabled and1’ if disabled.
5: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
6: Alternate names and definitions for these bits when the MSSP modules are operating in I2C™ Slave mode. See Section 19.4.3.2
“Address Masking Modes” for details
7: These bits and/or registers are only available in 80-pin devices; otherwise, they are unimplemented and read as ‘0’. Reset values are
shown for 80-pin devices.
8:
These bits are only available in select oscillator modes (FOSC2 Configuration bit =
0
); otherwise, they are unimplemented.
9: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the physical registers and addresses, but have different
functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
PIC18F87J11 FAMILY
DS39778C-page 80 Preliminary © 2008 Microchip Technology Inc.
5.3.5 STATUS REGISTER
The STATUS register, shown in Register 5-4, contains
the arithmetic status of the ALU. The STATUS register
can be the operand for any instruction, as with any
other register. If the STATUS register is the destination
for an instruction that affects the Z, DC, C, OV or N bits,
then the write to these five bits is disabled.
These bits are set or cleared according to the device
logic. Therefore, the result of an instruction with the
STATUS register as destination may be different than
intended. For example, CLRF STATUS will set the Z bit
but leave the other bits unchanged. The STATUS
register then reads back as ‘000u u1uu’. It is
recommended, therefore, that only BCF, BSF, SWAPF,
MOVFF and MOVWF instructions are used to alter the
STATUS register because these instructions do not
affect the Z, C, DC, OV or N bits in the STATUS
register.
For other instructions not affecting any Status bits, see
the instruction set summaries in Table 25-2 and
Table 25-3.
Note: The C and DC bits operate as a borrow and
digit borrow bit respectively, in subtraction.
REGISTER 5-4: STATUS REGISTER
U-0 U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x
—NOVZDC
(1) C(2)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as0
bit 4 N: Negative bit
This bit is used for signed arithmetic (2’s complement). It indicates whether the result was
negative (ALU MSB = 1).
1 = Result was negative
0 = Result was positive
bit 3 OV: Overflow bit
This bit is used for signed arithmetic (2’s complement). It indicates an overflow of the
7-bit magnitude which causes the sign bit (bit 7) to change state.
1 = Overflow occurred for signed arithmetic (in this arithmetic operation)
0 = No overflow occurred
bit 2 Z: Zero bit
1 = The result of an arithmetic or logic operation is zero
0 = The result of an arithmetic or logic operation is not zero
bit 1 DC: Digit carry/borrow bit(1)
For ADDWF, ADDLW, SUBLW and SUBWF instructions:
1 = A carry-out from the 4th low-order bit of the result occurred
0 = No carry-out from the 4th low-order bit of the result
bit 0 C: Carry/borrow bit(2)
For ADDWF, ADDLW, SUBLW and SUBWF instructions:
1 = A carry-out from the Most Significant bit of the result occurred
0 = No carry-out from the Most Significant bit of the result occurred
Note 1: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second
operand. For rotate (RRF, RLF) instructions, this bit is loaded with either bit 4 or bit 3 of the source register.
2: For borrow, the polarity is reversed. A subtraction is executed by adding the 2s complement of the second
operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low-order bit of the
source register.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 81
PIC18F87J11 FAMILY
5.4 Data Addressing Modes
While the program memory can be addressed in only
one way – through the program counter – information
in the data memory space can be addressed in several
ways. For most instructions, the addressing mode is
fixed. Other instructions may use up to three modes,
depending on which operands are used and whether or
not the extended instruction set is enabled.
The addressing modes are:
Inherent
Literal
•Direct
•Indirect
An additional addressing mode, Indexed Literal Offset,
is available when the extended instruction set is
enabled (XINST Configuration bit = 1). Its operation is
discussed in greater detail in Section 5.6.1 “Indexed
Addressing with Literal Offset”.
5.4.1 INHERENT AND LITERAL
ADDRESSING
Many PIC18 control instructions do not need any
argument at all; they either perform an operation that
globally affects the device, or they operate implicitly on
one register. This addressing mode is known as
Inherent Addressing. Examples include SLEEP, RESET
and DAW.
Other instructions work in a similar way, but require an
additional explicit argument in the opcode. This is
known as Literal Addressing mode, because they
require some literal value as an argument. Examples
include ADDLW and MOVLW, which respectively, add or
move a literal value to the W register. Other examples
include CALL and GOTO, which include a 20-bit
program memory address.
5.4.2 DIRECT ADDRESSING
Direct Addressing specifies all or part of the source
and/or destination address of the operation within the
opcode itself. The options are specified by the
arguments accompanying the instruction.
In the core PIC18 instruction set, bit-oriented and
byte-oriented instructions use some version of Direct
Addressing by default. All of these instructions include
some 8-bit Literal Address as their Least Significant
Byte. This address specifies either a register address in
one of the banks of data RAM (Section 5.3.3 “General
Purpose Register File”), or a location in the Access
Bank (Section 5.3.2 “Access Bank”) as the data
source for the instruction.
The Access RAM bit ‘a’ determines how the address is
interpreted. When ‘a’ is ‘1’, the contents of the BSR
(Section 5.3.1 “Bank Select Register”) are used with
the address to determine the complete 12-bit address
of the register. When ‘a’ is ‘0’, the address is interpreted
as being a register in the Access Bank. Addressing that
uses the Access RAM is sometimes also known as
Direct Forced Addressing mode.
A few instructions, such as MOVFF, include the entire
12-bit address (either source or destination) in their
opcodes. In these cases, the BSR is ignored entirely.
The destination of the operation’s results is determined
by the destination bit ‘d’. When ‘d’ is1’, the results are
stored back in the source register, overwriting its origi-
nal contents. When ‘d’ is0’, the results are stored in
the W register. Instructions without the ‘d’ argument
have a destination that is implicit in the instruction; their
destination is either the target register being operated
on or the W register.
5.4.3 INDIRECT ADDRESSING
Indirect Addressing allows the user to access a location
in data memory without giving a fixed address in the
instruction. This is done by using File Select Registers
(FSRs) as pointers to the locations to be read or written
to. Since the FSRs are themselves located in RAM as
Special Function Registers, they can also be directly
manipulated under program control. This makes FSRs
very useful in implementing data structures such as
tables and arrays in data memory.
The registers for Indirect Addressing are also
implemented with Indirect File Operands (INDFs) that
permit automatic manipulation of the pointer value with
auto-incrementing, auto-decrementing or offsetting
with another value. This allows for efficient code using
loops, such as the example of clearing an entire RAM
bank in Example 5-5. It also enables users to perform
Indexed Addressing and other Stack Pointer
operations for program memory in data memory.
EXAMPLE 5-5: HOW TO CLEAR RAM
(BANK 1) USING
INDIRECT ADDRESSING
Note: The execution of some instructions in the
core PIC18 instruction set are changed
when the PIC18 extended instruction set is
enabled. See Section 5.6 “Data Memory
and the Extended Instruction Set” for
more information.
LFSR FSR0, 100h ;
NEXT CLRF POSTINC0 ; Clear INDF
; register then
; inc pointer
BTFSS FSR0H, 1 ; All done with
; Bank1?
BRA NEXT ; NO, clear next
CONTINUE ; YES, continue
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DS39778C-page 82 Preliminary © 2008 Microchip Technology Inc.
5.4.3.1 FSR Registers and the
INDF Operand
At the core of Indirect Addressing are three sets of
registers: FSR0, FSR1 and FSR2. Each represents a
pair of 8-bit registers, FSRnH and FSRnL. The four
upper bits of the FSRnH register are not used, so each
FSR pair holds a 12-bit value. This represents a value
that can address the entire range of the data memory
in a linear fashion. The FSR register pairs, then, serve
as pointers to data memory locations.
Indirect Addressing is accomplished with a set of Indi-
rect File Operands, INDF0 through INDF2. These can
be thought of as “virtual” registers: they are mapped in
the SFR space but are not physically implemented.
Reading or writing to a particular INDF register actually
accesses its corresponding FSR register pair. A read
from INDF1, for example, reads the data at the address
indicated by FSR1H:FSR1L. Instructions that use the
INDF registers as operands actually use the contents
of their corresponding FSR as a pointer to the instruc-
tion’s target. The INDF operand is just a convenient
way of using the pointer.
Because Indirect Addressing uses a full 12-bit address,
data RAM banking is not necessary. Thus, the current
contents of the BSR and the Access RAM bit have no
effect on determining the target address.
FIGURE 5-9: INDIRECT ADDRESSING
FSR1H:FSR1L
0
7
Data Memory
000h
100h
200h
300h
F00h
E00h
FFFh
Bank 0
Bank 1
Bank 2
Bank 14
Bank 15
Bank 3
through
Bank 13
ADDWF, INDF1, 1
07
Using an instruction with one of the
Indirect Addressing registers as the
operand....
...uses the 12-bit address stored in
the FSR pair associated with that
register....
...to determine the data memory
location to be used in that operation.
In this case, the FSR1 pair contains
FCCh. This means the contents of
location FCCh will be added to that
of the W register and stored back in
FCCh.
xxxx1111 11001100
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 83
PIC18F87J11 FAMILY
5.4.3.2 FSR Registers and POSTINC,
POSTDEC, PREINC and PLUSW
In addition to the INDF operand, each FSR register pair
also has four additional indirect operands. Like INDF,
these are “virtual” registers that cannot be indirectly
read or written to. Accessing these registers actually
accesses the associated FSR register pair, but also
performs a specific action on its stored value. They are:
POSTDEC: accesses the FSR value, then
automatically decrements it by ‘1’ afterwards
POSTINC: accesses the FSR value, then
automatically increments it by ‘1’ afterwards
PREINC: increments the FSR value by ‘1’, then
uses it in the operation
PLUSW: adds the signed value of the W register
(range of -127 to 128) to that of the FSR and uses
the new value in the operation
In this context, accessing an INDF register uses the
value in the FSR registers without changing them.
Similarly, accessing a PLUSW register gives the FSR
value offset by the value in the W register; neither value
is actually changed in the operation. Accessing the
other virtual registers changes the value of the FSR
registers.
Operations on the FSRs with POSTDEC, POSTINC
and PREINC affect the entire register pair; that is, roll-
overs of the FSRnL register from FFh to 00h carry over
to the FSRnH register. On the other hand, results of
these operations do not change the value of any flags
in the STATUS register (e.g., Z, N, OV, etc.).
The PLUSW register can be used to implement a form
of Indexed Addressing in the data memory space. By
manipulating the value in the W register, users can
reach addresses that are fixed offsets from pointer
addresses. In some applications, this can be used to
implement some powerful program control structure,
such as software stacks, inside of data memory.
5.4.3.3 Operations by FSRs on FSRs
Indirect Addressing operations that target other FSRs
or virtual registers represent special cases. For exam-
ple, using an FSR to point to one of the virtual registers
will not result in successful operations. As a specific
case, assume that FSR0H:FSR0L contains FE7h, the
address of INDF1. Attempts to read the value of the
INDF1, using INDF0 as an operand, will return 00h.
Attempts to write to INDF1, using INDF0 as the
operand, will result in a NOP.
On the other hand, using the virtual registers to write to
an FSR pair may not occur as planned. In these cases,
the value will be written to the FSR pair but without any
incrementing or decrementing. Thus, writing to INDF2
or POSTDEC2 will write the same value to the
FSR2H:FSR2L.
Since the FSRs are physical registers mapped in the
SFR space, they can be manipulated through all direct
operations. Users should proceed cautiously when
working on these registers, particularly if their code
uses Indirect Addressing.
Similarly, operations by Indirect Addressing are gener-
ally permitted on all other SFRs. Users should exercise
the appropriate caution that they do not inadvertently
change settings that might affect the operation of the
device.
PIC18F87J11 FAMILY
DS39778C-page 84 Preliminary © 2008 Microchip Technology Inc.
5.5 Program Memory and the
Extended Instruction Set
The operation of program memory is unaffected by the
use of the extended instruction set.
Enabling the extended instruction set adds five
additional two-word commands to the existing PIC18
instruction set: ADDFSR, CALLW, MOVSF, MOVSS and
SUBFSR. These instructions are executed as described
in Section 5.2.4 “Two-Word Instructions”.
5.6 Data Memory and the Extended
Instruction Set
Enabling the PIC18 extended instruction set (XINST
Configuration bit = 1) significantly changes certain
aspects of data memory and its addressing. Specifi-
cally, the use of the Access Bank for many of the core
PIC18 instructions is different. This is due to the intro-
duction of a new addressing mode for the data memory
space. This mode also alters the behavior of Indirect
Addressing using FSR2 and its associated operands.
What does not change is just as important. The size of
the data memory space is unchanged, as well as its
linear addressing. The SFR map remains the same.
Core PIC18 instructions can still operate in both Direct
and Indirect Addressing mode; inherent and literal
instructions do not change at all. Indirect Addressing
with FSR0 and FSR1 also remains unchanged.
5.6.1 INDEXED ADDRESSING WITH
LITERAL OFFSET
Enabling the PIC18 extended instruction set changes
the behavior of Indirect Addressing using the FSR2
register pair and its associated file operands. Under the
proper conditions, instructions that use the Access
Bank – that is, most bit-oriented and byte-oriented
instructions – can invoke a form of Indexed Addressing
using an offset specified in the instruction. This special
addressing mode is known as Indexed Addressing with
Literal Offset, or Indexed Literal Offset mode.
When using the extended instruction set, this
addressing mode requires the following:
The use of the Access Bank is forced (‘a’ = 0);
and
The file address argument is less than or equal to
5Fh.
Under these conditions, the file address of the
instruction is not interpreted as the lower byte of an
address (used with the BSR in Direct Addressing) or as
an 8-bit address in the Access Bank. Instead, the value
is interpreted as an offset value to an Address Pointer
specified by FSR2. The offset and the contents of
FSR2 are added to obtain the target address of the
operation.
5.6.2 INSTRUCTIONS AFFECTED BY
INDEXED LITERAL OFFSET MODE
Any of the core PIC18 instructions that can use Direct
Addressing are potentially affected by the Indexed
Literal Offset Addressing mode. This includes all
byte-oriented and bit-oriented instructions, or almost
one-half of the standard PIC18 instruction set. Instruc-
tions that only use Inherent or Literal Addressing
modes are unaffected.
Additionally, byte-oriented and bit-oriented instructions
are not affected if they use the Access Bank (Access
RAM bit is ‘1’) or include a file address of 60h or above.
Instructions meeting these criteria will continue to
execute as before. A comparison of the different pos-
sible addressing modes when the extended instruction
set is enabled is shown in Figure 5-10.
Those who desire to use byte-oriented or bit-oriented
instructions in the Indexed Literal Offset mode should
note the changes to assembler syntax for this mode.
This is described in more detail in Section 25.2.1
“Extended Instruction Syntax”.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 85
PIC18F87J11 FAMILY
FIGURE 5-10: COMPARING ADDRESSING OPTIONS FOR BIT-ORIENTED AND
BYTE-ORIENTED INSTRUCTIONS (EXTENDED INSTRUCTION SET ENABLED)
EXAMPLE INSTRUCTION: ADDWF, f, d, a (Opcode: 0010 01da ffff ffff)
When a = 0 and f 60h:
The instruction executes in
Direct Forced mode. ‘f’ is
interpreted as a location in the
Access RAM between 060h
and FFFh. This is the same as
locations F60h to FFFh
(Bank 15) of data memory.
Locations below 060h are not
available in this addressing
mode.
When a = 0 and f5Fh:
The instruction executes in
Indexed Literal Offset mode. ‘f’
is interpreted as an offset to the
address value in FSR2. The
two are added together to
obtain the address of the target
register for the instruction. The
address can be anywhere in
the data memory space.
Note that in this mode, the
correct syntax is now:
ADDWF [k], d
where ‘k’ is the same as ‘f’.
When a = 1 (all values of f):
The instruction executes in
Direct mode (also known as
Direct Long mode). ‘f’ is
interpreted as a location in
one of the 16 banks of the data
memory space. The bank is
designated by the Bank Select
Register (BSR). The address
can be in any implemented
bank in the data memory
space.
000h
060h
100h
F00h
F60h
FFFh
Valid range
00h
60h
FFh
Data Memory
Access RAM
Bank 0
Bank 1
through
Bank 14
Bank 15
SFRs
000h
060h
100h
F00h
F60h
FFFh
Data Memory
Bank 0
Bank 1
through
Bank 14
Bank 15
SFRs
FSR2H FSR2L
ffffffff001001da
ffffffff001001da
000h
060h
100h
F00h
F60h
FFFh
Data Memory
Bank 0
Bank 1
through
Bank 14
Bank 15
SFRs
for ‘f’
BSR
00000000
PIC18F87J11 FAMILY
DS39778C-page 86 Preliminary © 2008 Microchip Technology Inc.
5.6.3 MAPPING THE ACCESS BANK IN
INDEXED LITERAL OFFSET MODE
The use of Indexed Literal Offset Addressing mode
effectively changes how the lower part of Access RAM
(00h to 5Fh) is mapped. Rather than containing just the
contents of the bottom part of Bank 0, this mode maps
the contents from Bank 0 and a user-defined “window”
that can be located anywhere in the data memory
space. The value of FSR2 establishes the lower bound-
ary of the addresses mapped into the window, while the
upper boundary is defined by FSR2 plus 95 (5Fh).
Addresses in the Access RAM above 5Fh are mapped
as previously described (see Section 5.3.2 “Access
Bank”). An example of Access Bank remapping in this
addressing mode is shown in Figure 5-11.
Remapping of the Access Bank applies only to opera-
tions using the Indexed Literal Offset mode. Operations
that use the BSR (Access RAM bit is ‘1’) will continue
to use Direct Addressing as before. Any Indirect or
Indexed Addressing operation that explicitly uses any
of the indirect file operands (including FSR2) will con-
tinue to operate as standard Indirect Addressing. Any
instruction that uses the Access Bank, but includes a
register address of greater than 05Fh, will use Direct
Addressing and the normal Access Bank map.
5.6.4 BSR IN INDEXED LITERAL
OFFSET MODE
Although the Access Bank is remapped when the
extended instruction set is enabled, the operation of the
BSR remains unchanged. Direct Addressing, using the
BSR to select the data memory bank, operates in the
same manner as previously described.
FIGURE 5-11: REMAPPING THE ACCESS BANK WITH INDEXED LITERAL
OFFSET ADDRESSING
Data Memory
000h
100h
200h
F60h
F00h
FFFh
Bank 1
Bank 15
Bank 2
through
Bank 14
SFRs
05Fh
ADDWF f, d, a
FSR2H:FSR2L = 120h
Locations in the region
from the FSR2 Pointer
(120h) to the pointer plus
05Fh (17Fh) are mapped
to the bottom of the
Access RAM (000h-05Fh).
Special Function Registers
at F60h through FFFh are
mapped to 60h through
FFh, as usual.
Bank 0 addresses below
5Fh are not available in
this mode. They can still
be addressed by using the
BSR.
Access Bank
00h
FFh
Bank 0
SFRs
Bank 1 “Window”
Not Accessible
Window
Example Situation:
120h
17Fh
5Fh
60h
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 87
PIC18F87J11 FAMILY
6.0 FLASH PROGRAM MEMORY
The Flash program memory is readable, writable and
erasable during normal operation over the entire VDD
range.
A read from program memory is executed on one byte
at a time. A write to program memory is executed on
blocks of 64 bytes at a time or two bytes at a time. Pro-
gram memory is erased in blocks of 1024 bytes at a
time. A bulk erase operation may not be issued from
user code.
Writing or erasing program memory will cease
instruction fetches until the operation is complete. The
program memory cannot be accessed during the write
or erase, therefore, code cannot execute. An internal
programming timer terminates program memory writes
and erases.
A value written to program memory does not need to be
a valid instruction. Executing a program memory
location that forms an invalid instruction results in a
NOP.
6.1 Table Reads and Table Writes
In order to read and write program memory, there are
two operations that allow the processor to move bytes
between the program memory space and the data RAM:
Table Read (TBLRD)
Table Write (TBLWT)
The program memory space is 16 bits wide, while the
data RAM space is 8 bits wide. Table reads and table
writes move data between these two memory spaces
through an 8-bit register (TABLAT).
Table read operations retrieve data from program
memory and place it into the data RAM space.
Figure 6-1 shows the operation of a table read with
program memory and data RAM.
Table write operations store data from the data memory
space into holding registers in program memory. The
procedure to write the contents of the holding registers
into program memory is detailed in Section 6.5 “Writing
to Flash Program Memory”. Figure 6-2 shows the
operation of a table write with program memory and data
RAM.
Table operations work with byte entities. A table block
containing data, rather than program instructions, is not
required to be word-aligned. Therefore, a table block can
start and end at any byte address. If a table write is being
used to write executable code into program memory,
program instructions will need to be word-aligned.
FIGURE 6-1: TABLE READ OPERATION
Table Pointer(1)
Table Latch (8-bit)
Program Memory
TBLPTRH TBLPTRL
TABLAT
TBLPTRU
Instruction: TBLRD*
Note 1: Table Pointer register points to a byte in program memory.
Program Memory
(TBLPTR)
PIC18F87J11 FAMILY
DS39778C-page 88 Preliminary © 2008 Microchip Technology Inc.
FIGURE 6-2: TABLE WRITE OPERATION
6.2 Control Registers
Several control registers are used in conjunction with
the TBLRD and TBLWT instructions. These include the:
EECON1 register
EECON2 register
TABLAT register
TBLPTR registers
6.2.1 EECON1 AND EECON2 REGISTERS
The EECON1 register (Register 6-1) is the control
register for memory accesses. The EECON2 register is
not a physical register; it is used exclusively in the
memory write and erase sequences. Reading
EECON2 will read all ‘0’s.
The WPROG bit, when set, allows the user to program
a single word (two bytes) upon the execution of the WR
command. If this bit is cleared, the WR command
programs a block of 64 bytes.
The FREE bit, when set, will allow a program memory
erase operation. When FREE is set, the erase
operation is initiated on the next WR command. When
FREE is clear, only writes are enabled.
The WREN bit, when set, will allow a write operation.
On power-up, the WREN bit is clear. The WRERR bit is
set in hardware when the WR bit is set and cleared
when the internal programming timer expires and the
write operation is complete.
The WR control bit initiates write operations. The bit
cannot be cleared, only set, in software. It is cleared in
hardware at the completion of the write operation.
Table Pointer(1) Table Latch (8-bit)
TBLPTRH TBLPTRL TABLAT
Program Memory
(TBLPTR)
TBLPTRU
Instruction: TBLWT*
Note 1: Table Pointer actually points to one of 64 holding registers, the address of which is determined by
TBLPTRL<5:0>. The process for physically writing data to the program memory array is discussed in
Section 6.5 “Writing to Flash Program Memory”.
Holding Registers
Program Memory
Note: During normal operation, the WRERR is
read as ‘1’. This can indicate that a write
operation was prematurely terminated by
a Reset, or a write operation was
attempted improperly.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 89
PIC18F87J11 FAMILY
REGISTER 6-1: EECON1: EEPROM CONTROL REGISTER 1
U-0 U-0 R/W-0 R/W-0 R/W-x R/W-0 R/S-0 U-0
WPROG FREE WRERR(1) WREN WR
bit 7 bit 0
Legend: S = Set-only bit (cannot be cleared in software)
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 Unimplemented: Read as0
bit 5 WPROG: One Word-Wide Program bit
1 = Program 2 bytes on the next WR command
0 = Program 64 bytes on the next WR command
bit 4 FREE: Flash Row Erase Enable bit
1 = Erase the program memory row addressed by TBLPTR on the next WR command
(cleared by completion of erase operation)
0 = Perform write only
bit 3 WRERR: Flash Program Error Flag bit(1)
1 = A write operation is prematurely terminated (any Reset during self-timed programming in normal
operation, or an improper write attempt)
0 = The write operation completed
bit 2 WREN: Flash Program Write Enable bit
1 = Allows write cycles to Flash program memory
0 = Inhibits write cycles to Flash program memory
bit 1 WR: Write Control bit
1 = Initiates a program memory erase cycle or write cycle
(The operation is self-timed and the bit is cleared by hardware once write is complete. The WR bit
can only be set (not cleared) in software.)
0 = Write cycle is complete
bit 0 Unimplemented: Read as0
Note 1: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows tracing of the error
condition.
PIC18F87J11 FAMILY
DS39778C-page 90 Preliminary © 2008 Microchip Technology Inc.
6.2.2 TABLE LATCH REGISTER (TABLAT)
The Table Latch (TABLAT) is an 8-bit register mapped
into the SFR space. The Table Latch register is used to
hold 8-bit data during data transfers between program
memory and data RAM.
6.2.3 TABLE POINTER REGISTER
(TBLPTR)
The Table Pointer (TBLPTR) register addresses a byte
within the program memory. The TBLPTR is comprised
of three SFR registers: Table Pointer Upper Byte, Table
Pointer High Byte and Table Pointer Low Byte
(TBLPTRU:TBLPTRH:TBLPTRL). These three regis-
ters join to form a 22-bit wide pointer. The low-order
21 bits allow the device to address up to 2 Mbytes of
program memory space. The 22nd bit allows access to
the device ID, the user ID and the Configuration bits.
The Table Pointer register, TBLPTR, is used by the
TBLRD and TBLWT instructions. These instructions can
update the TBLPTR in one of four ways based on the
table operation. These operations are shown in
Table 6-1. These operations on the TBLPTR only affect
the low-order 21 bits.
6.2.4 TABLE POINTER BOUNDARIES
TBLPTR is used in reads, writes and erases of the
Flash program memory.
When a TBLRD is executed, all 22 bits of the TBLPTR
determine which byte is read from program memory
into TABLAT.
When a TBLWT is executed, the seven LSbs of the
Table Pointer register (TBLPTR<6:0>) determine which
of the 64 program memory holding registers is written
to. When the timed write to program memory begins
(via the WR bit), the 12 MSbs of the TBLPTR
(TBLPTR<21:10>) determine which program memory
block of 1024 bytes is written to. For more detail, see
Section 6.5 “Writing to Flash Program Memory”.
When an erase of program memory is executed, the
12 MSbs of the Table Pointer register point to the
1024-byte block that will be erased. The Least
Significant bits are ignored.
Figure 6-3 describes the relevant boundaries of
TBLPTR based on Flash program memory operations.
TABLE 6-1: TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS
FIGURE 6-3: TABLE POINTER BOUNDARIES BASED ON OPERATION
Example Operation on Table Pointer
TBLRD*
TBLWT* TBLPTR is not modified
TBLRD*+
TBLWT*+ TBLPTR is incremented after the read/write
TBLRD*-
TBLWT*- TBLPTR is decremented after the read/write
TBLRD+*
TBLWT+* TBLPTR is incremented before the read/write
21 16 15 87 0
ERASE: TBLPTR<20:10>
TABLE WRITE: TBLPTR<20:6>
TABLE READ: TBLPTR<21:0>
TBLPTRLTBLPTRH
TBLPTRU
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 91
PIC18F87J11 FAMILY
6.3 Reading the Flash Program
Memory
The TBLRD instruction is used to retrieve data from
program memory and places it into data RAM. Table
reads from program memory are performed one byte at
a time.
TBLPTR points to a byte address in program space.
Executing TBLRD places the byte pointed to into
TABLAT. In addition, TBLPTR can be modified
automatically for the next table read operation.
The internal program memory is typically organized by
words. The Least Significant bit of the address selects
between the high and low bytes of the word. Figure 6-4
shows the interface between the internal program
memory and the TABLAT.
FIGURE 6-4: READS FROM FLASH PROGRAM MEMORY
EXAMPLE 6-1: READING A FLASH PROGRAM MEMORY WORD
(Even Byte Address)
Program Memory
(Odd Byte Address)
TBLRD TABLAT
TBLPTR = xxxxx1
FETCH
Instruction Register
(IR) Read Register
TBLPTR = xxxxx0
MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base
MOVWF TBLPTRU ; address of the word
MOVLW CODE_ADDR_HIGH
MOVWF TBLPTRH
MOVLW CODE_ADDR_LOW
MOVWF TBLPTRL
READ_WORD
TBLRD*+ ; read into TABLAT and increment
MOVF TABLAT, W ; get data
MOVWF WORD_EVEN
TBLRD*+ ; read into TABLAT and increment
MOVF TABLAT, W ; get data
MOVWF WORD_ODD
PIC18F87J11 FAMILY
DS39778C-page 92 Preliminary © 2008 Microchip Technology Inc.
6.4 Erasing Flash Program Memory
The minimum erase block is 512 words or 1024 bytes.
Only through the use of an external programmer, or
through ICSP control, can larger blocks of program
memory be bulk erased. Word erase in the Flash array
is not supported.
When initiating an erase sequence from the micro-
controller itself, a block of 1024 bytes of program
memory is erased. The Most Significant 12 bits of the
TBLPTR<21:10> point to the block being erased.
TBLPTR<9:0> are ignored.
The EECON1 register commands the erase operation.
The WREN bit must be set to enable write operations.
The FREE bit is set to select an erase operation. For
protection, the write initiate sequence for EECON2
must be used.
A long write is necessary for erasing the internal Flash.
Instruction execution is halted while in a long write
cycle. The long write will be terminated by the internal
programming timer.
6.4.1 FLASH PROGRAM MEMORY
ERASE SEQUENCE
The sequence of events for erasing a block of internal
program memory location is:
1. Load Table Pointer register with address of row
being erased.
2. Set the WREN and FREE bits (EECON1<2,4>)
to enable the erase operation.
3. Disable interrupts.
4. Write 55h to EECON2.
5. Write 0AAh to EECON2.
6. Set the WR bit. This will begin the row erase
cycle.
7. The CPU will stall for duration of the erase for
TIW (see parameter D133A).
8. Re-enable interrupts.
EXAMPLE 6-2: ERASING A FLASH PROGRAM MEMORY ROW
MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base
MOVWF TBLPTRU ; address of the memory block
MOVLW CODE_ADDR_HIGH
MOVWF TBLPTRH
MOVLW CODE_ADDR_LOW
MOVWF TBLPTRL
ERASE_ROW
BSF EECON1, FREE ; enable Row Erase operation
BCF INTCON, GIE ; disable interrupts
Required MOVLW 55h
Sequence MOVWF EECON2 ; write 55h
MOVLW 0AAh
MOVWF EECON2 ; write 0AAh
BSF EECON1, WR ; start erase (CPU stall)
BSF INTCON, GIE ; re-enable interrupts
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 93
PIC18F87J11 FAMILY
6.5 Writing to Flash Program Memory
The programming block is 32 words or 64 bytes.
Programming one word or two bytes at a time is also
supported.
Table writes are used internally to load the holding
registers needed to program the Flash memory. There
are 64 holding registers used by the table writes for
programming.
Since the Table Latch (TABLAT) is only a single byte, the
TBLWT instruction may need to be executed 64 times for
each programming operation (if WPROG = 0). All of the
table write operations will essentially be short writes
because only the holding registers are written. At the
end of updating the 64 holding registers, the EECON1
register must be written to in order to start the
programming operation with a long write.
The long write is necessary for programming the inter-
nal Flash. Instruction execution is halted while in a long
write cycle. The long write will be terminated by the
internal programming timer.
The on-chip timer controls the write time. The
write/erase voltages are generated by an on-chip
charge pump, rated to operate over the voltage range
of the device.
FIGURE 6-5: TABLE WRITES TO FLASH PROGRAM MEMORY
6.5.1 FLASH PROGRAM MEMORY WRITE
SEQUENCE
The sequence of events for programming an internal
program memory location should be:
1. Read 1024 bytes into RAM.
2. Update data values in RAM as necessary.
3. Load Table Pointer register with address being
erased.
4. Execute the row erase procedure.
5. Load Table Pointer register with address of first
byte being written, minus 1.
6. Write the 64 bytes into the holding registers with
auto-increment.
7. Set the WREN bit (EECON1<2>) to enable byte
writes.
8. Disable interrupts.
9. Write 55h to EECON2.
10. Write 0AAh to EECON2.
11. Set the WR bit. This will begin the write cycle.
12. The CPU will stall for duration of the write for TIW
(parameter D133A).
13. Re-enable interrupts.
14. Repeat steps 6 through 13 until all 1024 bytes
are written to program memory.
15. Verify the memory (table read).
An example of the required code is shown in
Example 6-3 on the following page.
Note 1: Unlike previous PIC18 Flash devices,
members of the PIC18F87J11 family do
not reset the holding registers after a
write occurs. The holding registers must
be cleared or overwritten before a
programming sequence.
2: To maintain the endurance of the program
memory cells, each Flash byte should not
be programmed more than one time
between erase operations. Before
attempting to modify the contents of the
target cell a second time, a row erase of
the target row, or a bulk erase of the entire
memory, must be performed.
TBLPTR = xxxx3FTBLPTR = xxxxx1TBLPTR = xxxxx0 TBLPTR = xxxxx2
Program Memory
Holding Register Holding Register Holding Register Holding Register
88 8 8
TABLAT
Write Register
Note: Before setting the WR bit, the Table
Pointer address needs to be within the
intended address range of the 64 bytes in
the holding register.
PIC18F87J11 FAMILY
DS39778C-page 94 Preliminary © 2008 Microchip Technology Inc.
EXAMPLE 6-3: WRITING TO FLASH PROGRAM MEMORY
MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base address
MOVWF TBLPTRU ; of the memory block, minus 1
MOVLW CODE_ADDR_HIGH
MOVWF TBLPTRH
MOVLW CODE_ADDR_LOW
MOVWF TBLPTRL
ERASE_BLOCK
BSF EECON1, WREN ; enable write to memory
BSF EECON1, FREE ; enable Row Erase operation
BCF INTCON, GIE ; disable interrupts
MOVLW 55h
MOVWF EECON2 ; write 55h
MOVLW 0AAh
MOVWF EECON2 ; write 0AAh
BSF EECON1, WR ; start erase (CPU stall)
BSF INTCON, GIE ; re-enable interrupts
MOVLW D'16'
MOVWF WRITE_COUNTER ; Need to write 16 blocks of 64 to write
; one erase block of 1024
RESTART_BUFFER
MOVLW D'64'
MOVWF COUNTER
MOVLW BUFFER_ADDR_HIGH ; point to buffer
MOVWF FSR0H
MOVLW BUFFER_ADDR_LOW
MOVWF FSR0L
FILL_BUFFER
... ; read the new data from I2C, SPI,
; PSP, USART, etc.
WRITE_BUFFER
MOVLW D’64 ; number of bytes in holding register
MOVWF COUNTER
WRITE_BYTE_TO_HREGS
MOVFF POSTINC0, WREG ; get low byte of buffer data
MOVWF TABLAT ; present data to table latch
TBLWT+* ; write data, perform a short write
; to internal TBLWT holding register.
DECFSZ COUNTER ; loop until buffers are full
BRA WRITE_BYTE_TO_HREGS
PROGRAM_MEMORY
BSF EECON1, WREN ; enable write to memory
BCF INTCON, GIE ; disable interrupts
MOVLW 55h
Required MOVWF EECON2 ; write 55h
Sequence MOVLW 0AAh
MOVWF EECON2 ; write 0AAh
BSF EECON1, WR ; start program (CPU stall)
BSF INTCON, GIE ; re-enable interrupts
BCF EECON1, WREN ; disable write to memory
DECFSZ WRITE_COUNTER ; done with one write cycle
BRA RESTART_BUFFER ; if not done replacing the erase block
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 95
PIC18F87J11 FAMILY
6.5.2 FLASH PROGRAM MEMORY WRITE
SEQUENCE (WORD
PROGRAMMING).
The PIC18F87J11 Family of devices have a feature
that allows programming a single word (two bytes).
This feature is enable when the WPROG bit is set. If the
memory location is already erased, the following
sequence is required to enable this feature:
1. Load the Table Pointer register with the address
of the data to be written
2. Write the 2 bytes into the holding registers and
perform a table write
3. Set the WREN bit (EECON1<2>) to enable byte
writes.
4. Disable interrupts.
5. Write 55h to EECON2.
6. Write 0AAh to EECON2.
7. Set the WR bit. This will begin the write cycle.
8. The CPU will stall for duration of the write for TIW
(see parameter D133A).
9. Re-enable interrupts.
EXAMPLE 6-4: SINGLE-WORD WRITE TO FLASH PROGRAM MEMORY
MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base address
MOVWF TBLPTRU
MOVLW CODE_ADDR_HIGH
MOVWF TBLPTRH
MOVLW CODE_ADDR_LOW
MOVWF TBLPTRL
MOVLW DATA0
MOVWF TABLAT
TBLWT*+
MOVLW DATA1
MOVWF TABLAT
TBLWT*
PROGRAM_MEMORY
BSF EECON1, WPROG ; enable single word write
BSF EECON1, WREN ; enable write to memory
BCF INTCON, GIE ; disable interrupts
MOVLW 55h
Required MOVWF EECON2 ; write 55h
Sequence MOVLW 0AAh
MOVWF EECON2 ; write 0AAh
BSF EECON1, WR ; start program (CPU stall)
BSF INTCON, GIE ; re-enable interrupts
BCF EECON1, WPROG ; disable single word write
BCF EECON1, WREN ; disable write to memory
PIC18F87J11 FAMILY
DS39778C-page 96 Preliminary © 2008 Microchip Technology Inc.
6.5.3 WRITE VERIFY
Depending on the application, good programming
practice may dictate that the value written to the
memory should be verified against the original value.
This should be used in applications where excessive
writes can stress bits near the specification limit.
6.5.4 UNEXPECTED TERMINATION OF
WRITE OPERATION
If a write is terminated by an unplanned event, such as
loss of power or an unexpected Reset, the memory
location just programmed should be verified and repro-
grammed if needed. If the write operation is interrupted
by a MCLR Reset or a WDT time-out Reset during
normal operation, the user can check the WRERR bit
and rewrite the location(s) as needed.
6.6 Flash Program Operation During
Code Protection
See Section 24.6 “Program Verification and Code
Protection” for details on code protection of Flash
program memory.
TABLE 6-2: REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values on
Page:
TBLPTRU bit 21 Program Memory Table Pointer Upper Byte
(TBLPTR<20:16>)
55
TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 55
TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 55
TABLAT Program Memory Table Latch 55
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
EECON2 Program Memory Control Register 2 (not a physical register) 57
EECON1 WPROG FREE WRERR WREN WR —57
Legend: = unimplemented, read as ‘0’. Shaded cells are not used during Flash program memory access.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 97
PIC18F87J11 FAMILY
7.0 EXTERNAL MEMORY BUS
The External Memory Bus (EMB) allows the device to
access external memory devices (such as Flash,
EPROM, SRAM, etc.) as program or data memory. It
supports both 8 and 16-Bit Data Width modes and
three address widths of up to 20 bits.
The bus is implemented with 28 pins, multiplexed
across four I/O ports. Three ports (PORTD, PORTE
and PORTH) are multiplexed with the address/data bus
for a total of 20 available lines, while PORTJ is
multiplexed with the bus control signals.
A list of the pins and their functions is provided in
Table 7-1.
TABLE 7-1: PIC18F87J11 FAMILY EXTERNAL BUS – I/O PORT FUNCTIONS
Note: The external memory bus is not
implemented on 64-pin devices.
Name Port Bit External Memory Bus Function
RD0/AD0 PORTD 0 Address bit 0 or Data bit 0
RD1/AD1 PORTD 1 Address bit 1 or Data bit 1
RD2/AD2 PORTD 2 Address bit 2 or Data bit 2
RD3/AD3 PORTD 3 Address bit 3 or Data bit 3
RD4/AD4 PORTD 4 Address bit 4 or Data bit 4
RD5/AD5 PORTD 5 Address bit 5 or Data bit 5
RD6/AD6 PORTD 6 Address bit 6 or Data bit 6
RD7/AD7 PORTD 7 Address bit 7 or Data bit 7
RE0/AD8 PORTE 0 Address bit 8 or Data bit 8
RE1/AD9 PORTE 1 Address bit 9 or Data bit 9
RE2/AD10 PORTE 2 Address bit 10 or Data bit 10
RE3/AD11 PORTE 3 Address bit 11 or Data bit 11
RE4/AD12 PORTE 4 Address bit 12 or Data bit 12
RE5/AD13 PORTE 5 Address bit 13 or Data bit 13
RE6/AD14 PORTE 6 Address bit 14 or Data bit 14
RE7/AD15 PORTE 7 Address bit 15 or Data bit 15
RH0/A16 PORTH 0 Address bit 16
RH1/A17 PORTH 1 Address bit 17
RH2/A18 PORTH 2 Address bit 18
RH3/A19 PORTH 3 Address bit 19
RJ0/ALE PORTJ 0 Address Latch Enable (ALE) Control pin
RJ1/OE PORTJ 1 Output Enable (OE) Control pin
RJ2/WRL PORTJ 2 Write Low (WRL) Control pin
RJ3/WRH PORTJ 3 Write High (WRH) Control pin
RJ4/BA0 PORTJ 4 Byte Address bit 0 (BA0)
RJ5/CE PORTJ 5 Chip Enable (CE) Control pin
RJ6/LB PORTJ 6 Lower Byte Enable (LB) Control pin
RJ7/UB PORTJ 7 Upper Byte Enable (UB) Control pin
Note: For the sake of clarity, only I/O port and external bus assignments are shown here. One or more additional
multiplexed features may be available on some pins.
PIC18F87J11 FAMILY
DS39778C-page 98 Preliminary © 2008 Microchip Technology Inc.
7.1 External Memory Bus Control
The operation of the interface is controlled by the
MEMCON register (Register 7-1). This register is
available in all program memory operating modes
except Microcontroller mode. In this mode, the register
is disabled and cannot be written to.
The EBDIS bit (MEMCON<7>) controls the operation
of the bus and related port functions. Clearing EBDIS
enables the interface and disables the I/O functions of
the ports, as well as any other functions multiplexed to
those pins. Setting the bit enables the I/O ports and
other functions, but allows the interface to override
everything else on the pins when an external memory
operation is required. By default, the external bus is
always enabled and disables all other I/O.
The operation of the EBDIS bit is also influenced by the
program memory mode being used. This is discussed
in more detail in Section 7.5 “Program Memory
Modes and the External Memory Bus”.
The WAIT bits allow for the addition of wait states to
external memory operations. The use of these bits is
discussed in Section 7.3 “Wait States”.
The WM bits select the particular operating mode used
when the bus is operating in 16-Bit Data Width mode.
These are discussed in more detail in Section 7.6
“16-Bit Data Width Modes”. These bits have no effect
when an 8-bit Data Width mode is selected.
The MEMCON register (see Register 7-1) shares the
same memory space as the PR2 register and can be
alternately selected based on the designation of the
ADSHR bit in the WDTCON register (see
Register 24-9).
REGISTER 7-1: MEMCON: EXTERNAL MEMORY BUS CONTROL REGISTER
R/W-0 U-0 R/W-0 R/W-0 U-0 U-0 R/W-0 R/W-0
EBDIS —WAIT1WAIT0—WM1WM0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 EBDIS: External Bus Disable bit
1 = External bus enabled when microcontroller accesses external memory; otherwise, all external bus
drivers are mapped as I/O ports
0 = External bus always enabled, I/O ports are disabled
bit 6 Unimplemented: Read as ‘0
bit 5-4 WAIT1:WAIT0: Table Reads and Writes Bus Cycle Wait Count bits
11 = Table reads and writes will wait 0 TCY
10 = Table reads and writes will wait 1 TCY
01 = Table reads and writes will wait 2 TCY
00 = Table reads and writes will wait 3 TCY
bit 3-2 Unimplemented: Read as ‘0
bit 1-0 WM1:WM0: TBLWT Operation with 16-Bit Data Bus Width Select bits
1x = Word Write mode: TABLAT word output, WRH active when TABLAT written
01 = Byte Select mode: TABLAT data copied on both MSB and LSB, WRH and (UB or LB) will activate
00 = Byte Write mode: TABLAT data copied on both MSB and LSB, WRH or WRL will activate
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 99
PIC18F87J11 FAMILY
7.2 Address and Data Width
The PIC18F87J11 Family of devices can be indepen-
dently configured for different address and data widths
on the same memory bus. Both address and data width
are set by Configuration bits in the CONFIG3L register.
As Configuration bits, this means that these options
can only be configured by programming the device and
are not controllable in software.
The BW bit selects an 8-bit or 16-bit data bus width.
Setting this bit (default) selects a data width of 16 bits.
The EMB1:EMB0 bits determine both the program
memory operating mode and the address bus width.
The available options are 20-bit, 16-bit and 12-bit, as
well as Microcontroller mode (external bus disabled).
Selecting a 16-bit or 12-bit width makes a correspond-
ing number of high-order lines available for I/O
functions. These pins are no longer affected by the
setting of the EBDIS bit. For example, selecting a
16-Bit Addressing mode (EMB1:EMB0 = 01) disables
A19:A16 and allows PORTH<3:0> to function without
interruptions from the bus. Using the smaller address
widths allows users to tailor the memory bus to the size
of the external memory space for a particular design
while freeing up pins for dedicated I/O operation.
Because the EMB bits have the effect of disabling pins
for memory bus operations, it is important to always
select an address width at least equal to the data width.
If a 12-bit address width is used with a 16-bit data
width, the upper four bits of data will not be available on
the bus.
All combinations of address and data widths require
multiplexing of address and data information on the
same lines. The address and data multiplexing, as well
as I/O ports made available by the use of smaller
address widths, are summarized in Table 7-2.
7.2.1 ADDRESS SHIFTING ON THE
EXTERNAL BUS
By default, the address presented on the external bus
is the value of the PC. In practical terms, this means
that addresses in the external memory device below
the top of on-chip memory are unavailable to the micro-
controller. To access these physical locations, the glue
logic between the microcontroller and the external
memory must somehow translate addresses.
To simplify the interface, the external bus offers an
extension of Extended Microcontroller mode that
automatically performs address shifting. This feature is
controlled by the EASHFT Configuration bit. Setting
this bit offsets addresses on the bus by the size of the
microcontroller’s on-chip program memory and sets
the bottom address at 0000h. This allows the device to
use the entire range of physical addresses of the
external memory.
7.2.2 21-BIT ADDRESSING
As an extension of 20-bit address width operation, the
external memory bus can also fully address a 2-Mbyte
memory space. This is done by using the Bus Address
bit 0 (BA0) control line as the Least Significant bit of the
address. The UB and LB control signals may also be
used with certain memory devices to select the upper
and lower bytes within a 16-bit wide data word.
This addressing mode is available in both 8-bit and
certain 16-Bit Data Width modes. Additional details are
provided in Section 7.6.3 “16-Bit Byte Select Mode”
and Section 7.7 “8-Bit Data Width Mode”.
TABLE 7-2: ADDRESS AND DATA LINES FOR DIFFERENT ADDRESS AND DATA WIDTHS
Data Width Address Width
Multiplexed Data and
Address Lines (and
Corresponding Ports)
Address Only
Lines (and
Corresponding Ports)
Ports Available
for I/O
8-bit
12-bit
AD7:AD0
(PORTD<7:0>)
AD11:AD8
(PORTE<3:0>)
PORTE<7:4>,
All of PORTH
16-bit AD15:AD8
(PORTE<7:0>) All of PORTH
20-bit
A19:A16, AD15:AD8
(PORTH<3:0>,
PORTE<7:0>)
16-bit
16-bit AD15:AD0
(PORTD<7:0>,
PORTE<7:0>)
All of PORTH
20-bit A19:A16
(PORTH<3:0>)
PIC18F87J11 FAMILY
DS39778C-page 100 Preliminary © 2008 Microchip Technology Inc.
7.3 Wait States
While it may be assumed that external memory devices
will operate at the microcontroller clock rate, this is
often not the case. In fact, many devices require longer
times to write or retrieve data than the time allowed by
the execution of table read or table write operations.
To compensate for this, the external memory bus can
be configured to add a fixed delay to each table opera-
tion using the bus. Wait states are enabled by setting
the WAIT Configuration bit. When enabled, the amount
of delay is set by the WAIT1:WAIT0 bits
(MEMCON<5:4>). The delay is based on multiples of
microcontroller instruction cycle time and are added
following the instruction cycle when the table operation
is executed. The range is from no delay to 3 TCY
(default value).
7.4 Port Pin Weak Pull-ups
With the exception of the upper address lines,
A19:A16, the pins associated with the external memory
bus are equipped with weak pull-ups. The pull-ups are
controlled by the upper three bits of the PORTG
register (PORTG<7:5>). They are named RDPU,
REPU and RJPU and control pull-ups on PORTD,
PORTE and PORTJ, respectively. Setting one of these
bits enables the corresponding pull-ups for that port. All
pull-ups are disabled by default on all device Resets.
In Extended Microcontroller mode, the port pull-ups
can be useful in preserving the memory state on the
external bus while the bus is temporarily disabled
(EBDIS = ‘1’).
7.5 Program Memory Modes and the
External Memory Bus
The PIC18F87J11 Family of devices is capable of
operating in one of two program memory modes, using
combinations of on-chip and external program memory.
The functions of the multiplexed port pins depend on
the program memory mode selected, as well as the
setting of the EBDIS bit.
In Microcontroller Mode, the bus is not active and the
pins have their port functions only. Writes to the
MEMCOM register are not permitted. The Reset value
of EBDIS (‘0’) is ignored and EMB pins behave as I/O
ports.
In Extended Microcontroller Mode, the external
program memory bus shares I/O port functions on the
pins. When the device is fetching or doing table
read/table write operations on the external program
memory space, the pins will have the external bus
function.
If the device is fetching and accessing internal program
memory locations only, the EBDIS control bit will
change the pins from external memory to I/O port
functions. When EBDIS = 0, the pins function as the
external bus. When EBDIS = 1, the pins function as I/O
ports.
If the device fetches or accesses external memory
while EBDIS = 1, the pins will switch to external bus. If
the EBDIS bit is set by a program executing from exter-
nal memory, the action of setting the bit will be delayed
until the program branches into the internal memory. At
that time, the pins will change from external bus to I/O
ports.
If the device is executing out of internal memory when
EBDIS = 0, the memory bus address/data and control
pins will not be active. They will go to a state where the
active address/data pins are tri-state; the CE, OE,
WRH, WRL, UB and LB signals are ‘1 and ALE and
BA0 are 0’. Note that only those pins associated with
the current address width are forced to tri-state; the
other pins continue to function as I/O. In the case of
16-bit address width, for example, only AD<15:0>
(PORTD and PORTE) are affected; A19:A16
(PORTH<3:0>) continue to function as I/O.
In all external memory modes, the bus takes priority
over any other peripherals that may share pins with it.
This includes the Parallel Master Port and serial
communication modules which would otherwise take
priority over the I/O port.
7.6 16-Bit Data Width Modes
In 16-Bit Data Width mode, the external memory
interface can be connected to external memories in
three different configurations:
16-Bit Byte Write
16-Bit Word Write
16-Bit Byte Select
The configuration to be used is determined by the
WM1:WM0 bits in the MEMCON register
(MEMCON<1:0>). These three different configurations
allow the designer maximum flexibility in using both
8-bit and 16-bit devices with 16-bit data.
For all 16-bit modes, the Address Latch Enable (ALE)
pin indicates that the address bits, AD<15:0>, are avail-
able on the external memory interface bus. Following
the address latch, the Output Enable signal (OE) will
enable both bytes of program memory at once to form
a 16-bit instruction word. The Chip Enable signal (CE)
is active at any time that the microcontroller accesses
external memory, whether reading or writing; it is
inactive (asserted high) whenever the device is in
Sleep mode.
In Byte Select mode, JEDEC standard Flash memories
will require BA0 for the byte address line and one I/O
line to select between Byte and Word mode. The other
16-bit modes do not need BA0. JEDEC standard static
RAM memories will use the UB or LB signals for byte
selection.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 101
PIC18F87J11 FAMILY
7.6.1 16-BIT BYTE WRITE MODE
Figure 7-1 shows an example of 16-Bit Byte Write
mode for PIC18F87J11 Family devices. This mode is
used for two separate 8-bit memories connected for
16-bit operation. This generally includes basic EPROM
and Flash devices. It allows table writes to byte-wide
external memories.
During a TBLWT instruction cycle, the TABLAT data is
presented on the upper and lower bytes of the
AD15:AD0 bus. The appropriate WRH or WRL control
line is strobed on the LSb of the TBLPTR.
FIGURE 7-1: 16-BIT BYTE WRITE MODE EXAMPLE
AD<7:0>
A<19:16>(1)
ALE
D<15:8>
373 A<x:0>
D<7:0>
A<19:0> A<x:0>
D<7:0>
373
OE
WRH
OE OE
WR(2) WR(2)
CE CE
Note 1: Upper order address lines are used only for 20-bit address widths.
2: This signal only applies to table writes. See Section 6.1 “Table Reads and Table Writes”.
WRL
D<7:0>
(LSB)
(MSB)
PIC18F87J11
D<7:0>
AD<15:8>
Address Bus
Data Bus
Control Lines
CE
PIC18F87J11 FAMILY
DS39778C-page 102 Preliminary © 2008 Microchip Technology Inc.
7.6.2 16-BIT WORD WRITE MODE
Figure 7-2 shows an example of 16-Bit Word Write
mode for PIC18F87J11 Family devices. This mode is
used for word-wide memories which include some of
the EPROM and Flash-type memories. This mode
allows opcode fetches and table reads from all forms of
16-bit memory and table writes to any type of
word-wide external memories. This method makes a
distinction between TBLWT cycles to even or odd
addresses.
During a TBLWT cycle to an even address
(TBLPTR<0> = 0), the TABLAT data is transferred to a
holding latch and the external address data bus is
tri-stated for the data portion of the bus cycle. No write
signals are activated.
During a TBLWT cycle to an odd address
(TBLPTR<0> = 1), the TABLAT data is presented on
the upper byte of the AD15:AD0 bus. The contents of
the holding latch are presented on the lower byte of the
AD15:AD0 bus.
The WRH signal is strobed for each write cycle; the
WRL pin is unused. The signal on the BA0 pin indicates
the LSb of the TBLPTR, but it is left unconnected.
Instead, the UB and LB signals are active to select both
bytes. The obvious limitation to this method is that the
table write must be done in pairs on a specific word
boundary to correctly write a word location.
FIGURE 7-2: 16-BIT WORD WRITE MODE EXAMPLE
AD<7:0>
PIC18F87J11
AD<15:8>
ALE
373 A<20:1>
373
OE
WRH
A<19:16>(1)
A<x:0>
D<15:0>
OE WR(2)
CE
D<15:0>
JEDEC Word
EPROM Memory
Address Bus
Data Bus
Control Lines
Note 1: Upper order address lines are used only for 20-bit address widths.
2: This signal only applies to table writes. See Section 6.1 “Table Reads and Table Writes”.
CE
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 103
PIC18F87J11 FAMILY
7.6.3 16-BIT BYTE SELECT MODE
Figure 7-3 shows an example of 16-Bit Byte Select
mode. This mode allows table write operations to
word-wide external memories with byte selection
capability. This generally includes both word-wide
Flash and SRAM devices.
During a TBLWT cycle, the TABLAT data is presented
on the upper and lower byte of the AD15:AD0 bus. The
WRH signal is strobed for each write cycle; the WRL
pin is not used. The BA0 or UB/LB signals are used to
select the byte to be written, based on the Least
Significant bit of the TBLPTR register.
Flash and SRAM devices use different control signal
combinations to implement Byte Select mode. JEDEC
standard Flash memories require that a controller I/O
port pin be connected to the memory’s BYTE/WORD
pin to provide the select signal. They also use the BA0
signal from the controller as a byte address. JEDEC
standard static RAM memories, on the other hand, use
the UB or LB signals to select the byte.
FIGURE 7-3: 16-BIT BYTE SELECT MODE EXAMPLE
AD<7:0>
PIC18F87J11
AD<15:8>
ALE
373
A<20:1>
373
OE
WRH
A<19:16>(2)
WRL
BA0
JEDEC Word
A<x:1>
D<15:0>
A<20:1>
CE
D<15:0>
I/O
OE WR(1)
A0
BYTE/WORD
FLASH Memory
JEDEC Word
A<x:1>
D<15:0>
CE
D<15:0>
OE WR(1)
LB
UB
SRAM Memory
LB
UB
138(3)
Address Bus
Data Bus
Control Lines
Note 1: This signal only applies to table writes. See Section 6.1 “Table Reads and Table Writes”.
2: Upper order address lines are used only for 20-bit address width.
3: Demultiplexing is only required when multiple memory devices are accessed.
PIC18F87J11 FAMILY
DS39778C-page 104 Preliminary © 2008 Microchip Technology Inc.
7.6.4 16-BIT MODE TIMING
The presentation of control signals on the external
memory bus is different for the various operating
modes. Typical signal timing diagrams are shown in
Figure 7-4 and Figure 7-5.
FIGURE 7-4: EXTERNAL MEMORY BUS TIMING FOR TBLRD (EXTENDED
MICROCONTROLLER MODE)
FIGURE 7-5: EXTERNAL MEMORY BUS TIMING FOR SLEEP (EXTENDED
MICROCONTROLLER MODE)
Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4
A<19:16>
ALE
OE
AD<15:0>
CE
Opcode Fetch Opcode Fetch Opcode Fetch
TBLRD *
TBLRD Cycle 1
ADDLW 55h
from 000100h
Q2Q1 Q3 Q4
0Ch
CF33h
TBLRD 92h
from 199E67h
9256h
from 000104h
Memory
Cycle
Instruction
Execution INST(PC – 2) TBLRD Cycle 2
MOVLW 55h
from 000102h
MOVLW
Q2Q1 Q3 Q4 Q2Q1 Q3 Q4
A<19:16>
ALE
OE
3AAAh
AD<15:0>
00h 00h
CE
Opcode Fetch Opcode Fetch
SLEEP
SLEEP
from 007554h
Q1
Bus Inactive
0003h
3AABh
0E55h
Memory
Cycle
Instruction
Execution INST(PC – 2)
Sleep Mode,
MOVLW 55h
from 007556h
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 105
PIC18F87J11 FAMILY
7.7 8-Bit Data Width Mode
In 8-Bit Data Width mode, the external memory bus
operates only in Multiplexed mode; that is, data shares
the 8 Least Significant bits of the address bus.
Figure 7-6 shows an example of 8-Bit Multiplexed
mode for 80-pin devices. This mode is used for a single
8-bit memory connected for 16-bit operation. The
instructions will be fetched as two 8-bit bytes on a
shared data/address bus. The two bytes are sequen-
tially fetched within one instruction cycle (TCY).
Therefore, the designer must choose external memory
devices according to timing calculations based on
1/2 TCY (2 times the instruction rate). For proper mem-
ory speed selection, glue logic propagation delay times
must be considered, along with setup and hold times.
The Address Latch Enable (ALE) pin indicates that the
address bits, AD<15:0>, are available on the external
memory interface bus. The Output Enable signal (OE)
will enable one byte of program memory for a portion of
the instruction cycle, then BA0 will change and the
second byte will be enabled to form the 16-bit instruc-
tion word. The Least Significant bit of the address, BA0,
must be connected to the memory devices in this
mode. The Chip Enable signal (CE) is active at any
time that the microcontroller accesses external
memory, whether reading or writing. It is inactive
(asserted high) whenever the device is in Sleep mode.
This generally includes basic EPROM and Flash
devices. It allows table writes to byte-wide external
memories.
During a TBLWT instruction cycle, the TABLAT data is
presented on the upper and lower bytes of the
AD15:AD0 bus. The appropriate level of the BA0
control line is strobed on the LSb of the TBLPTR.
FIGURE 7-6: 8-BIT MULTIPLEXED MODE EXAMPLE
AD<7:0>
A<19:16>(1)
ALE D<15:8>
373 A<19:0> A<x:1>
D<7:0>
OE
OE WR(2)
CE
Note 1: Upper order address bits are only used for 20-bit address width. The upper AD byte is used for all
address widths except 8-bit.
2: This signal only applies to table writes. See Section 6.1 “Table Reads and Table Writes”.
WRL
D<7:0>
PIC18F87J11
AD<15:8>(1)
Address Bus
Data Bus
Control Lines
CE
A0
BA0
PIC18F87J11 FAMILY
DS39778C-page 106 Preliminary © 2008 Microchip Technology Inc.
7.7.1 8-BIT MODE TIMING
The presentation of control signals on the external
memory bus is different for the various operating
modes. Typical signal timing diagrams are shown in
Figure 7-7 and Figure 7-8.
FIGURE 7-7: EXTERNAL MEMORY BUS TIMING FOR TBLRD (EXTENDED
MICROCONTROLLER MODE)
FIGURE 7-8: EXTERNAL MEMORY BUS TIMING FOR SLEEP (EXTENDED
MICROCONTROLLER MODE)
Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4
A<19:16>
ALE
OE
AD<7:0>
CE
Opcode Fetch Opcode Fetch Opcode Fetch
TBLRD *
TBLRD Cycle 1
ADDLW 55h
from 000100h
Q2Q1 Q3 Q4
0Ch
33h
TBLRD 92h
from 199E67h
92h
from 000104h
Memory
Cycle
Instruction
Execution INST(PC – 2) TBLRD Cycle 2
MOVLW 55h
from 000102h
MOVLW
AD<15:8> CFh
Q2Q1 Q3 Q4 Q2Q1 Q3 Q4
A<19:16>
ALE
OE
AAh
AD<7:0>
00h 00h
CE
Opcode Fetch Opcode Fetch
SLEEP
SLEEP
from 007554h
Q1
Bus Inactive
00h ABh 55h
Memory
Cycle
Instruction
Execution INST(PC – 2)
Sleep Mode,
MOVLW 55h
from 007556h
AD<15:8> 3Ah 3Ah
03h 0Eh
BA0
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 107
PIC18F87J11 FAMILY
7.8 Operation in Power-Managed
Modes
In alternate, power-managed Run modes, the external
bus continues to operate normally. If a clock source
with a lower speed is selected, bus operations will run
at that speed. In these cases, excessive access times
for the external memory may result if wait states have
been enabled and added to external memory opera-
tions. If operations in a lower power Run mode are
anticipated, users should provide in their applications
for adjusting memory access times at the lower clock
speeds.
In Sleep and Idle modes, the microcontroller core does
not need to access data; bus operations are
suspended. The state of the external bus is frozen, with
the address/data pins and most of the control pins hold-
ing at the same state they were in when the mode was
invoked. The only potential changes are the CE, LB
and UB pins, which are held at logic high.
PIC18F87J11 FAMILY
DS39778C-page 108 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 109
PIC18F87J11 FAMILY
8.0 8 x 8 HARDWARE MULTIPLIER
8.1 Introduction
All PIC18 devices include an 8 x 8 hardware multiplier
as part of the ALU. The multiplier performs an unsigned
operation and yields a 16-bit result that is stored in the
product register pair, PRODH:PRODL. The multiplier’s
operation does not affect any flags in the STATUS
register.
Making multiplication a hardware operation allows it to
be completed in a single instruction cycle. This has the
advantages of higher computational throughput and
reduced code size for multiplication algorithms and
allows the PIC18 devices to be used in many applica-
tions previously reserved for digital signal processors.
A comparison of various hardware and software
multiply operations, along with the savings in memory
and execution time, is shown in Table 8-1.
8.2 Operation
Example 8-1 shows the instruction sequence for an 8 x 8
unsigned multiplication. Only one instruction is required
when one of the arguments is already loaded in the
WREG register.
Example 8-2 shows the sequence to do an 8 x 8 signed
multiplication. To account for the sign bits of the argu-
ments, each argument’s Most Significant bit (MSb) is
tested and the appropriate subtractions are done.
EXAMPLE 8-1: 8 x 8 UNSIGNED
MULTIPLY ROUTINE
EXAMPLE 8-2: 8 x 8 SIGNED MULTIPLY
ROUTINE
TABLE 8-1: PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS
MOVF ARG1, W ;
MULWF ARG2 ; ARG1 * ARG2 ->
; PRODH:PRODL
MOVF ARG1, W
MULWF ARG2 ; ARG1 * ARG2 ->
; PRODH:PRODL
BTFSC ARG2, SB ; Test Sign Bit
SUBWF PRODH, F ; PRODH = PRODH
; - ARG1
MOVF ARG2, W
BTFSC ARG1, SB ; Test Sign Bit
SUBWF PRODH, F ; PRODH = PRODH
; - ARG2
Routine Multiply Method
Program
Memory
(Words)
Cycles
(Max)
Time
@ 48 MHz @ 10 MHz @ 4 MHz
8 x 8 unsigned Without hardware multiply 13 69 5.7 μs27.6 μs69 μs
Hardware multiply 1 1 83.3 ns 400 ns 1 μs
8 x 8 signed Without hardware multiply 33 91 7.5 μs36.4 μs91 μs
Hardware multiply 6 6 500 ns 2.4 μs6 μs
16 x 16 unsigned Without hardware multiply 21 242 20.1 μs96.8 μs242 μs
Hardware multiply 28 28 2.3 μs 11.2 μs28 μs
16 x 16 signed Without hardware multiply 52 254 21.6 μs 102.6 μs254 μs
Hardware multiply 35 40 3.3 μs16.0 μs40 μs
PIC18F87J11 FAMILY
DS39778C-page 110 Preliminary © 2008 Microchip Technology Inc.
Example 8-3 shows the sequence to do a 16 x 16
unsigned multiplication. Equation 8-1 shows the
algorithm that is used. The 32-bit result is stored in four
registers (RES3:RES0).
EQUATION 8-1: 16 x 16 UNSIGNED
MULTIPLICATION
ALGORITHM
EXAMPLE 8-3: 16 x 16 UNSIGNED
MULTIPLY ROUTINE
Example 8-4 shows the sequence to do a 16 x 16
signed multiply. Equation 8-2 shows the algorithm
used. The 32-bit result is stored in four registers
(RES3:RES0). To account for the sign bits of the
arguments, the MSb for each argument pair is tested
and the appropriate subtractions are done.
EQUATION 8-2: 16 x 16 SIGNED
MULTIPLICATION
ALGORITHM
EXAMPLE 8-4: 16 x 16 SIGNED
MULTIPLY ROUTINE
RES3:RES0 = ARG1H:ARG1L ARG2H:ARG2L
= (ARG1H ARG2H 216) +
(ARG1H ARG2L 28) +
(ARG1L ARG2H 28) +
(ARG1L ARG2L)
MOVF ARG1L, W
MULWF ARG2L ; ARG1L * ARG2L->
; PRODH:PRODL
MOVFF PRODH, RES1 ;
MOVFF PRODL, RES0 ;
;
MOVF ARG1H, W
MULWF ARG2H ; ARG1H * ARG2H->
; PRODH:PRODL
MOVFF PRODH, RES3 ;
MOVFF PRODL, RES2 ;
;
MOVF ARG1L, W
MULWF ARG2H ; ARG1L * ARG2H->
; PRODH:PRODL
MOVF PRODL, W ;
ADDWF RES1, F ; Add cross
MOVF PRODH, W ; products
ADDWFC RES2, F ;
CLRF WREG ;
ADDWFC RES3, F ;
;
MOVF ARG1H, W ;
MULWF ARG2L ; ARG1H * ARG2L->
; PRODH:PRODL
MOVF PRODL, W ;
ADDWF RES1, F ; Add cross
MOVF PRODH, W ; products
ADDWFC RES2, F ;
CLRF WREG ;
ADDWFC RES3, F ;
RES3:RES0 = ARG1H:ARG1L ARG2H:ARG2L
= (ARG1H ARG2H 216) +
(ARG1H ARG2L 28) +
(ARG1L ARG2H 28) +
(ARG1L ARG2L) +
(-1 ARG2H<7> ARG1H:ARG1L 216) +
(-1 ARG1H<7> ARG2H:ARG2L 216)
MOVF ARG1L, W
MULWF ARG2L ; ARG1L * ARG2L ->
; PRODH:PRODL
MOVFF PRODH, RES1 ;
MOVFF PRODL, RES0 ;
;
MOVF ARG1H, W
MULWF ARG2H ; ARG1H * ARG2H ->
; PRODH:PRODL
MOVFF PRODH, RES3 ;
MOVFF PRODL, RES2 ;
;
MOVF ARG1L, W
MULWF ARG2H ; ARG1L * ARG2H ->
; PRODH:PRODL
MOVF PRODL, W ;
ADDWF RES1, F ; Add cross
MOVF PRODH, W ; products
ADDWFC RES2, F ;
CLRF WREG ;
ADDWFC RES3, F ;
;
MOVF ARG1H, W ;
MULWF ARG2L ; ARG1H * ARG2L ->
; PRODH:PRODL
MOVF PRODL, W ;
ADDWF RES1, F ; Add cross
MOVF PRODH, W ; products
ADDWFC RES2, F ;
CLRF WREG ;
ADDWFC RES3, F ;
;
BTFSS ARG2H, 7 ; ARG2H:ARG2L neg?
BRA SIGN_ARG1 ; no, check ARG1
MOVF ARG1L, W ;
SUBWF RES2 ;
MOVF ARG1H, W ;
SUBWFB RES3
;
SIGN_ARG1
BTFSS ARG1H, 7 ; ARG1H:ARG1L neg?
BRA CONT_CODE ; no, done
MOVF ARG2L, W ;
SUBWF RES2 ;
MOVF ARG2H, W ;
SUBWFB RES3
;
CONT_CODE
:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 111
PIC18F87J11 FAMILY
9.0 INTERRUPTS
Members of the PIC18F87J11 Family of devices have
multiple interrupt sources and an interrupt priority fea-
ture that allows most interrupt sources to be assigned
a high-priority level or a low-priority level. The
high-priority interrupt vector is at 0008h and the
low-priority interrupt vector is at 0018h. High-priority
interrupt events will interrupt any low-priority interrupts
that may be in progress.
There are thirteen registers which are used to control
interrupt operation. These registers are:
RCON
•INTCON
INTCON2
INTCON3
PIR1, PIR2, PIR3
PIE1, PIE2, PIE3
IPR1, IPR2, IPR3
It is recommended that the Microchip header files
supplied with MPLAB® IDE be used for the symbolic bit
names in these registers. This allows the
assembler/compiler to automatically take care of the
placement of these bits within the specified register.
In general, interrupt sources have three bits to control
their operation. They are:
Flag bit to indicate that an interrupt event
occurred
Enable bit that allows program execution to
branch to the interrupt vector address when the
flag bit is set
Priority bit to select high-priority or low-priority
The interrupt priority feature is enabled by setting the
IPEN bit (RCON<7>). When interrupt priority is
enabled, there are two bits which enable interrupts
globally. Setting the GIEH bit (INTCON<7>) enables all
interrupts that have the priority bit set (high priority).
Setting the GIEL bit (INTCON<6>) enables all
interrupts that have the priority bit cleared (low priority).
When the interrupt flag, enable bit and appropriate
global interrupt enable bit are set, the interrupt will
vector immediately to address 0008h or 0018h,
depending on the priority bit setting. Individual
interrupts can be disabled through their corresponding
enable bits.
When the IPEN bit is cleared (default state), the
interrupt priority feature is disabled and interrupts are
compatible with PIC16 mid-range devices. In
Compatibility mode, the interrupt priority bits for each
source have no effect. INTCON<6> is the PEIE bit
which enables/disables all peripheral interrupt sources.
INTCON<7> is the GIE bit which enables/disables all
interrupt sources. All interrupts branch to address
0008h in Compatibility mode.
When an interrupt is responded to, the global interrupt
enable bit is cleared to disable further interrupts. If the
IPEN bit is cleared, this is the GIE bit. If interrupt priority
levels are used, this will be either the GIEH or GIEL bit.
High-priority interrupt sources can interrupt a
low-priority interrupt. Low-priority interrupts are not
processed while high-priority interrupts are in progress.
The return address is pushed onto the stack and the
PC is loaded with the interrupt vector address (0008h
or 0018h). Once in the Interrupt Service Routine, the
source(s) of the interrupt can be determined by polling
the interrupt flag bits. The interrupt flag bits must be
cleared in software before re-enabling interrupts to
avoid recursive interrupts.
The “return from interrupt” instruction, RETFIE, exits
the interrupt routine and sets the GIE bit (GIEH or GIEL
if priority levels are used) which re-enables interrupts.
For external interrupt events, such as the INTx pins or
the PORTB input change interrupt, the interrupt latency
will be three to four instruction cycles. The exact
latency is the same for one or two-cycle instructions.
Individual interrupt flag bits are set regardless of the
status of their corresponding enable bit or the GIE bit.
Note: Do not use the MOVFF instruction to modify
any of the interrupt control registers while
any interrupt is enabled. Doing so may
cause erratic microcontroller behavior.
PIC18F87J11 FAMILY
DS39778C-page 112 Preliminary © 2008 Microchip Technology Inc.
FIGURE 9-1: PIC18F87J11 FAMILY INTERRUPT LOGIC
TMR0IE
GIE/GIEH
PEIE/GIEL
Wake-up if in
Interrupt to CPU
Vector to Location
0008h
INT2IF
INT2IE
INT2IP
INT1IF
INT1IE
INT1IP
TMR0IF
TMR0IE
TMR0IP
RBIF
RBIE
RBIP
IPEN
TMR0IF
TMR0IP
INT1IF
INT1IE
INT1IP
INT2IF
INT2IE
INT2IP
RBIF
RBIE
RBIP
INT0IF
INT0IE
PEIE/GIEL
Interrupt to CPU
Vector to Location
IPEN
IPEN
0018h
PIR1<7:0>
PIE1<7:0>
IPR1<7:0>
High-Priority Interrupt Generation
Low-Priority Interrupt Generation
Idle or Sleep modes
GIE/GIEH
INT3IF
INT3IE
INT3IP
INT3IF
INT3IE
INT3IP
PIR2<7:5, 3:0>
PIE2<7:5, 3:0>
IPR2<7:5, 3:0>
PIR3<7, 0>
PIE3<7, 0>
IPR3<7, 0>
PIR1<7:0>
PIE1<7:0>
IPR1<7:0>
PIR2<7:5, 3:0>
PIE2<7:5, 3:0>
IPR2<7:5, 3:0>
PIR3<7, 0>
PIE3<7, 0>
IPR3<7, 0>
IPEN
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 113
PIC18F87J11 FAMILY
9.1 INTCON Registers
The INTCON registers are readable and writable
registers which contain various enable, priority and flag
bits.
Note: Interrupt flag bits are set when an interrupt
condition occurs regardless of the state of
its corresponding enable bit or the global
interrupt enable bit. User software should
ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt.
This feature allows for software polling.
REGISTER 9-1: INTCON: INTERRUPT CONTROL REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x
GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 GIE/GIEH: Global Interrupt Enable bit
When IPEN = 0:
1 = Enables all unmasked interrupts
0 = Disables all interrupts
When IPEN = 1:
1 = Enables all high-priority interrupts
0 = Disables all interrupts
bit 6 PEIE/GIEL: Peripheral Interrupt Enable bit
When IPEN = 0:
1 = Enables all unmasked peripheral interrupts
0 = Disables all peripheral interrupts
When IPEN = 1:
1 = Enables all low-priority peripheral interrupts
0 = Disables all low-priority peripheral interrupts
bit 5 TMR0IE: TMR0 Overflow Interrupt Enable bit
1 = Enables the TMR0 overflow interrupt
0 = Disables the TMR0 overflow interrupt
bit 4 INT0IE: INT0 External Interrupt Enable bit
1 = Enables the INT0 external interrupt
0 = Disables the INT0 external interrupt
bit 3 RBIE: RB Port Change Interrupt Enable bit
1 = Enables the RB port change interrupt
0 = Disables the RB port change interrupt
bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit
1 = TMR0 register has overflowed (must be cleared in software)
0 = TMR0 register did not overflow
bit 1 INT0IF: INT0 External Interrupt Flag bit
1 = The INT0 external interrupt occurred (must be cleared in software)
0 = The INT0 external interrupt did not occur
bit 0 RBIF: RB Port Change Interrupt Flag bit(1)
1 = At least one of the RB7:RB4 pins changed state (must be cleared in software)
0 = None of the RB7:RB4 pins have changed state
Note 1: A mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and
allow the bit to be cleared.
PIC18F87J11 FAMILY
DS39778C-page 114 Preliminary © 2008 Microchip Technology Inc.
REGISTER 9-2: INTCON2: INTERRUPT CONTROL REGISTER 2
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 RBPU: PORTB Pull-up Enable bit
1 = All PORTB pull-ups are disabled
0 = PORTB pull-ups are enabled by individual port latch values
bit 6 INTEDG0: External Interrupt 0 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 5 INTEDG1: External Interrupt 1 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 4 INTEDG2: External Interrupt 2 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 3 INTEDG3: External Interrupt 3 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 2 TMR0IP: TMR0 Overflow Interrupt Priority bit
1 =High priority
0 = Low priority
bit 1 INT3IP: INT3 External Interrupt Priority bit
1 =High priority
0 = Low priority
bit 0 RBIP: RB Port Change Interrupt Priority bit
1 =High priority
0 = Low priority
Note: Interrupt flag bits are set when an interrupt condition occurs regardless of the state of its corresponding
enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt. This feature allows for software polling.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 115
PIC18F87J11 FAMILY
REGISTER 9-3: INTCON3: INTERRUPT CONTROL REGISTER 3
R/W-1 R/W-1 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 INT2IP: INT2 External Interrupt Priority bit
1 =High priority
0 = Low priority
bit 6 INT1IP: INT1 External Interrupt Priority bit
1 =High priority
0 = Low priority
bit 5 INT3IE: INT3 External Interrupt Enable bit
1 = Enables the INT3 external interrupt
0 = Disables the INT3 external interrupt
bit 4 INT2IE: INT2 External Interrupt Enable bit
1 = Enables the INT2 external interrupt
0 = Disables the INT2 external interrupt
bit 3 INT1IE: INT1 External Interrupt Enable bit
1 = Enables the INT1 external interrupt
0 = Disables the INT1 external interrupt
bit 2 INT3IF: INT3 External Interrupt Flag bit
1 = The INT3 external interrupt occurred (must be cleared in software)
0 = The INT3 external interrupt did not occur
bit 1 INT2IF: INT2 External Interrupt Flag bit
1 = The INT2 external interrupt occurred (must be cleared in software)
0 = The INT2 external interrupt did not occur
bit 0 INT1IF: INT1 External Interrupt Flag bit
1 = The INT1 external interrupt occurred (must be cleared in software)
0 = The INT1 external interrupt did not occur
Note: Interrupt flag bits are set when an interrupt condition occurs regardless of the state of its corresponding
enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt. This feature allows for software polling.
PIC18F87J11 FAMILY
DS39778C-page 116 Preliminary © 2008 Microchip Technology Inc.
9.2 PIR Registers
The PIR registers contain the individual flag bits for the
peripheral interrupts. Due to the number of peripheral
interrupt sources, there are three Peripheral Interrupt
Request (Flag) registers (PIR1, PIR2, PIR3).
Note 1: Interrupt flag bits are set when an interrupt
condition occurs regardless of the state of
its corresponding enable bit or the Global
Interrupt Enable bit, GIE (INTCON<7>).
2: User software should ensure the
appropriate interrupt flag bits are cleared
prior to enabling an interrupt and after
servicing that interrupt.
REGISTER 9-4: PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1
R/W-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0
PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 PMPIF: Parallel Master Port Read/Write Interrupt Flag bit
1 = A read or a write operation has taken place (must be cleared in software)
0 = No read or write has occurred
bit 6 ADIF: A/D Converter Interrupt Flag bit
1 = An A/D conversion completed (must be cleared in software)
0 = The A/D conversion is not complete
bit 5 RC1IF: EUSART1 Receive Interrupt Flag bit
1 = The EUSART1 receive buffer, RCREG1, is full (cleared when RCREG1 is read)
0 = The EUSART1 receive buffer is empty
bit 4 TX1IF: EUSART1 Transmit Interrupt Flag bit
1 = The EUSART1 transmit buffer, TXREG1, is empty (cleared when TXREG1 is written)
0 = The EUSART1 transmit buffer is full
bit 3 SSP1IF: MSSP1 Interrupt Flag bit
1 = The transmission/reception is complete (must be cleared in software)
0 = Waiting to transmit/receive
bit 2 CCP1IF: ECCP1 Interrupt Flag bit
Capture mode:
1 = A TMR1/TMR3 register capture occurred (must be cleared in software)
0 = No TMR1/TMR3 register capture occurred
Compare mode:
1 = A TMR1/TMR3 register compare match occurred (must be cleared in software)
0 = No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
bit 1 TMR2IF: TMR2 to PR2 Match Interrupt Flag bit
1 = TMR2 to PR2 match occurred (must be cleared in software)
0 = No TMR2 to PR2 match occurred
bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit
1 = TMR1 register overflowed (must be cleared in software)
0 = TMR1 register did not overflow
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 117
PIC18F87J11 FAMILY
REGISTER 9-5: PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2
R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0
OSCFIF CM2IF CM1IF BCL1IF LVDIF TMR3IF CCP2IF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 OSCFIF: Oscillator Fail Interrupt Flag bit
1 = Device oscillator failed, clock input has changed to INTOSC (must be cleared in software)
0 = Device clock operating
bit 6 CM2IF: Comparator 2 Interrupt Flag bit
1 = Comparator input has changed (must be cleared in software)
0 = Comparator input has not changed
bit 5 CM1IF: Comparator 1 Interrupt Flag bit
1 = Comparator input has changed (must be cleared in software)
0 = Comparator input has not changed
bit 4 Unimplemented: Read as0
bit 3 BCL1IF: Bus Collision Interrupt Flag bit (MSSP1 module)
1 = A bus collision occurred (must be cleared in software)
0 = No bus collision occurred
bit 2 LVDIF: Low-Voltage Detect Interrupt Flag bit
1 = A low-voltage condition occurred (must be cleared in software)
0 =V
DDCORE has not fallen below the low-voltage trip point (about 2.45V)
bit 1 TMR3IF: TMR3 Overflow Interrupt Flag bit
1 = TMR3 register overflowed (must be cleared in software)
0 = TMR3 register did not overflow
bit 0 CCP2IF: ECCP2 Interrupt Flag bit
Capture mode:
1 = A TMR1/TMR3 register capture occurred (must be cleared in software)
0 = No TMR1/TMR3 register capture occurred
Compare mode:
1 = A TMR1/TMR3 register compare match occurred (must be cleared in software)
0 = No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
PIC18F87J11 FAMILY
DS39778C-page 118 Preliminary © 2008 Microchip Technology Inc.
REGISTER 9-6: PIR3: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 3
R/W-0 R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SSP2IF: MSSP2 Interrupt Flag bit
1 = The transmission/reception is complete (must be cleared in software)
0 = Waiting to transmit/receive
bit 6 BCL2IF: Bus Collision Interrupt Flag bit (MSSP2 module)
1 = A bus collision occurred (must be cleared in software)
0 = No bus collision occurred
bit 5 RC2IF: EUSART2 Receive Interrupt Flag bit
1 = The EUSART2 receive buffer, RCREG2, is full (cleared when RCREG2 is read)
0 = The EUSART2 receive buffer is empty
bit 4 TX2IF: EUSART2 Transmit Interrupt Flag bit
1 = The EUSART2 transmit buffer, TXREG2, is empty (cleared when TXREG2 is written)
0 = The EUSART2 transmit buffer is full
bit 3 TMR4IF: TMR4 to PR4 Match Interrupt Flag bit
1 = TMR4 to PR4 match occurred (must be cleared in software)
0 = No TMR4 to PR4 match occurred
bit 2 CCP5IF: CCP5 Interrupt Flag bit
Capture mode:
1 = A TMR1/TMR3 register capture occurred (must be cleared in software)
0 = No TMR1/TMR3 register capture occurred
Compare mode:
1 = A TMR1/TMR3 register compare match occurred (must be cleared in software)
0 = No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
bit 1 CCP4IF: CCP4 Interrupt Flag bit
Capture mode:
1 = A TMR1/TMR3 register capture occurred (must be cleared in software)
0 = No TMR1/TMR3 register capture occurred
Compare mode:
1 = A TMR1/TMR3 register compare match occurred (must be cleared in software)
0 = No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
bit 0 CCP3IF: ECCP3 Interrupt Flag bit
Capture mode:
1 = A TMR1/TMR3 register capture occurred (must be cleared in software)
0 = No TMR1/TMR3 register capture occurred
Compare mode:
1 = A TMR1/TMR3 register compare match occurred (must be cleared in software)
0 = No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 119
PIC18F87J11 FAMILY
9.3 PIE Registers
The PIE registers contain the individual enable bits for
the peripheral interrupts. Due to the number of
peripheral interrupt sources, there are three Peripheral
Interrupt Enable registers (PIE1, PIE2, PIE3). When
IPEN = 0, the PEIE bit must be set to enable any of
these peripheral interrupts.
REGISTER 9-7: PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 PMPIE: Parallel Master Port Read/Write Interrupt Enable bit
1 = Enables the PM read/write interrupt
0 = Disables the PM read/write interrupt
bit 6 ADIE: A/D Converter Interrupt Enable bit
1 = Enables the A/D interrupt
0 = Disables the A/D interrupt
bit 5 RC1IE: EUSART1 Receive Interrupt Enable bit
1 = Enables the EUSART1 receive interrupt
0 = Disables the EUSART1 receive interrupt
bit 4 TX1IE: EUSART1 Transmit Interrupt Enable bit
1 = Enables the EUSART1 transmit interrupt
0 = Disables the EUSART1 transmit interrupt
bit 3 SSP1IE: MSSP1 Interrupt Enable bit
1 = Enables the MSSP1 interrupt
0 = Disables the MSSP1 interrupt
bit 2 CCP1IE: ECCP1 Interrupt Enable bit
1 = Enables the ECCP1 interrupt
0 = Disables the ECCP1 interrupt
bit 1 TMR2IE: TMR2 to PR2 Match Interrupt Enable bit
1 = Enables the TMR2 to PR2 match interrupt
0 = Disables the TMR2 to PR2 match interrupt
bit 0 TMR1IE: TMR1 Overflow Interrupt Enable bit
1 = Enables the TMR1 overflow interrupt
0 = Disables the TMR1 overflow interrupt
PIC18F87J11 FAMILY
DS39778C-page 120 Preliminary © 2008 Microchip Technology Inc.
REGISTER 9-8: PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2
R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0
OSCFIE CM2IE CM1IE BCL1IE LVDIE TMR3IE CCP2IE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 OSCFIE: Oscillator Fail Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 6 CM2IE: Comparator 2 Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 5 CM1IE: Comparator 1 Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 4 Unimplemented: Read as0
bit 3 BCL1IE: Bus Collision Interrupt Enable bit (MSSP1 module)
1 = Enabled
0 = Disabled
bit 2 LVDIE: Low-Voltage Detect Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 1 TMR3IE: TMR3 Overflow Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 0 CCP2IE: ECCP2 Interrupt Enable bit
1 = Enabled
0 = Disabled
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 121
PIC18F87J11 FAMILY
REGISTER 9-9: PIE3: PERIPHERAL INTERRUPT ENABLE REGISTER 3
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SSP2IE: MSSP2 Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 6 BCL2IE: Bus Collision Interrupt Enable bit (MSSP2 module)
1 = Enabled
0 = Disabled
bit 5 RC2IE: EUSART2 Receive Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 4 TX2IE: EUSART2 Transmit Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 3 TMR4IE: TMR4 to PR4 Match Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 2 CCP5IE: CCP5 Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 1 CCP4IE: CCP4 Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 0 CCP3IE: ECCP3 Interrupt Enable bit
1 = Enabled
0 = Disabled
PIC18F87J11 FAMILY
DS39778C-page 122 Preliminary © 2008 Microchip Technology Inc.
9.4 IPR Registers
The IPR registers contain the individual priority bits for
the peripheral interrupts. Due to the number of
peripheral interrupt sources, there are three Peripheral
Interrupt Priority registers (IPR1, IPR2, IPR3). Using
the priority bits requires that the Interrupt Priority
Enable (IPEN) bit be set.
REGISTER 9-10: IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 PMPIP: Parallel Master Port Read/Write Interrupt Priority bit
1 =High priority
0 = Low priority
bit 6 ADIP: A/D Converter Interrupt Priority bit
1 =High priority
0 = Low priority
bit 5 RC1IP: EUSART1 Receive Interrupt Priority bit
1 =High priority
0 = Low priority
bit 4 TX1IP: EUSART1 Transmit Interrupt Priority bit
1 =High priority
0 = Low priority
bit 3 SSP1IP: MSSP1 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 2 CCP1IP: ECCP1 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 1 TMR2IP: TMR2 to PR2 Match Interrupt Priority bit
1 =High priority
0 = Low priority
bit 0 TMR1IP: TMR1 Overflow Interrupt Priority bit
1 =High priority
0 = Low priority
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 123
PIC18F87J11 FAMILY
REGISTER 9-11: IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2
R/W-1 R/W-1 R/W-1 U-0 R/W-1 R/W-1 R/W-1 R/W-1
OSCFIP CM2IP CM1IP BCL1IP LVDIP TMR3IP CCP2IP
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 OSCFIP: Oscillator Fail Interrupt Priority bit
1 =High priority
0 = Low priority
bit 6 CM2IP: Comparator 2 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 5 C12IP: Comparator 1 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 4 Unimplemented: Read as0
bit 3 BCL1IP: Bus Collision Interrupt Priority bit (MSSP1 module)
1 =High priority
0 = Low priority
bit 2 LVDIP: Low-Voltage Detect Interrupt Priority bit
1 =High priority
0 = Low priority
bit 1 TMR3IP: TMR3 Overflow Interrupt Priority bit
1 =High priority
0 = Low priority
bit 0 CCP2IP: ECCP2 Interrupt Priority bit
1 =High priority
0 = Low priority
PIC18F87J11 FAMILY
DS39778C-page 124 Preliminary © 2008 Microchip Technology Inc.
REGISTER 9-12: IPR3: PERIPHERAL INTERRUPT PRIORITY REGISTER 3
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SSP2IP: MSSP2 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 6 BCL2IP: Bus Collision Interrupt Priority bit (MSSP2 module)
1 =High priority
0 = Low priority
bit 5 RC2IP: EUSART2 Receive Interrupt Priority bit
1 =High priority
0 = Low priority
bit 4 TX2IP: EUSART2 Transmit Interrupt Priority bit
1 =High priority
0 = Low priority
bit 3 TMR4IE: TMR4 to PR4 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 2 CCP5IP: CCP5 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 1 CCP4IP: CCP4 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 0 CCP3IP: ECCP3 Interrupt Priority bit
1 =High priority
0 = Low priority
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 125
PIC18F87J11 FAMILY
9.5 RCON Register
The RCON register contains bits used to determine the
cause of the last Reset or wake-up from Idle or Sleep
modes. RCON also contains the bit that enables
interrupt priorities (IPEN).
REGISTER 9-13: RCON: RESET CONTROL REGISTER
R/W-0 U-0 R/W-1 R/W-1 R-1 R-1 R/W-0 R/W-0
IPEN —CMRI TO PD POR BOR
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IPEN: Interrupt Priority Enable bit
1 = Enable priority levels on interrupts
0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode)
bit 6 Unimplemented: Read as0
bit 5 CM: Configuration Mismatch Flag bit
For details of bit operation, see Register 4-1.
bit 4 RI: RESET Instruction Flag bit
For details of bit operation, see Register 4-1.
bit 3 TO: Watchdog Timer Time-out Flag bit
For details of bit operation, see Register 4-1.
bit 2 PD: Power-Down Detection Flag bit
For details of bit operation, see Register 4-1.
bit 1 POR: Power-on Reset Status bit
For details of bit operation, see Register 4-1.
bit 0 BOR: Brown-out Reset Status bit
For details of bit operation, see Register 4-1.
PIC18F87J11 FAMILY
DS39778C-page 126 Preliminary © 2008 Microchip Technology Inc.
9.6 INTx Pin Interrupts
External interrupts on the RB0/INT0, RB1/INT1,
RB2/INT2 and RB3/INT3 pins are edge-triggered. If the
corresponding INTEDGx bit in the INTCON2 register is
set (= 1), the interrupt is triggered by a rising edge; if
the bit is clear, the trigger is on the falling edge. When
a valid edge appears on the RBx/INTx pin, the
corresponding flag bit, INTxIF, is set. This interrupt can
be disabled by clearing the corresponding enable bit,
INTxIE. Flag bit, INTxIF, must be cleared in software in
the Interrupt Service Routine before re-enabling the
interrupt.
All external interrupts (INT0, INT1, INT2 and INT3) can
wake-up the processor from the power-managed
modes if bit INTxIE was set prior to going into the
power-managed modes. If the Global Interrupt Enable
bit, GIE, is set, the processor will branch to the interrupt
vector following wake-up.
Interrupt priority for INT1, INT2 and INT3 is determined
by the value contained in the interrupt priority bits,
INT1IP (INTCON3<6>), INT2IP (INTCON3<7>) and
INT3IP (INTCON2<1>). There is no priority bit
associated with INT0. It is always a high-priority
interrupt source.
9.7 TMR0 Interrupt
In 8-bit mode (which is the default), an overflow in the
TMR0 register (FFh 00h) will set flag bit, TMR0IF. In
16-bit mode, an overflow in the TMR0H:TMR0L register
pair (FFFFh 0000h) will set TMR0IF. The interrupt
can be enabled/disabled by setting/clearing enable bit,
TMR0IE (INTCON<5>). Interrupt priority for Timer0 is
determined by the value contained in the interrupt prior-
ity bit, TMR0IP (INTCON2<2>). See Section 12.0
“Timer0 Module” for further details on the Timer0
module.
9.8 PORTB Interrupt-on-Change
An input change on PORTB<7:4> sets flag bit, RBIF
(INTCON<0>). The interrupt can be enabled/disabled
by setting/clearing enable bit, RBIE (INTCON<3>).
Interrupt priority for PORTB interrupt-on-change is
determined by the value contained in the interrupt
priority bit, RBIP (INTCON2<0>).
9.9 Context Saving During Interrupts
During interrupts, the return PC address is saved on
the stack. Additionally, the WREG, STATUS and BSR
registers are saved on the Fast Return Stack. If a fast
return from interrupt is not used (see Section 5.3
“Data Memory Organization”), the user may need to
save the WREG, STATUS and BSR registers on entry
to the Interrupt Service Routine. Depending on the
user’s application, other registers may also need to be
saved. Example 9-1 saves and restores the WREG,
STATUS and BSR registers during an Interrupt Service
Routine.
EXAMPLE 9-1: SAVING STATUS, WREG AND BSR REGISTERS IN RAM
MOVWF W_TEMP ; W_TEMP is in virtual bank
MOVFF STATUS, STATUS_TEMP ; STATUS_TEMP located anywhere
MOVFF BSR, BSR_TEMP ; BSR_TMEP located anywhere
;
; USER ISR CODE
;
MOVFF BSR_TEMP, BSR ; Restore BSR
MOVF W_TEMP, W ; Restore WREG
MOVFF STATUS_TEMP, STATUS ; Restore STATUS
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 127
PIC18F87J11 FAMILY
10.0 I/O PORTS
Depending on the device selected and features
enabled, there are up to nine ports available. Some
pins of the I/O ports are multiplexed with an alternate
function from the peripheral features on the device. In
general, when a peripheral is enabled, that pin may not
be used as a general purpose I/O pin.
Each port has three memory-mapped registers for its
operation:
TRIS register (Data Direction register)
PORT register (reads the levels on the pins of the
device)
LAT register (Output Latch register)
Reading the PORT register reads the current status of
the pins, whereas writing to the PORT register writes to
the Output Latch (LAT) register.
Setting a TRIS bit (= 1) makes the corresponding
PORT pin an input (i.e., puts the corresponding output
driver in a high-impedance mode). Clearing a TRIS bit
(= 0) makes the corresponding PORT pin an output
(i.e., puts the contents of the corresponding LAT bit on
the selected pin).
The Output Latch (LAT register) is useful for
read-modify-write operations on the value that the I/O
pins are driving. Read-modify-write operations on the
LAT register read and write the latched output value for
the PORT register.
A simplified model of a generic I/O port, without the
interfaces to other peripherals, is shown in Figure 10-1.
FIGURE 10-1: GENERIC I/O PORT
OPERATION
10.1 I/O Port Pin Capabilities
When developing an application, the capabilities of the
port pins must be considered. Outputs on some pins
have higher output drive strength than others. Similarly,
some pins can tolerate higher than VDD input levels.
10.1.1 INPUT PINS AND VOLTAGE
CONSIDERATIONS
The voltage tolerance of pins used as device inputs is
dependent on the pin’s input function. Pins that are
used as digital only inputs are able to handle DC
voltages up to 5.5V, a level typical for digital logic
circuits. In contrast, pins that also have analog input
functions of any kind (such as A/D and comparator
inputs) can only tolerate voltages up to VDD. Voltage
excursions beyond VDD on these pins should be
avoided.
Table 10-1 summarizes the input capabilities. Refer to
Section 27.0 “Electrical Characteristics for more
details.
TABLE 10-1: INPUT VOLTAGE LEVELS
10.1.2 PIN OUTPUT DRIVE
When used as digital I/O, the output pin drive strengths
vary for groups of pins intended to meet the needs for
a variety of applications. In general, there are three
classes of output pins in terms of drive capability.
PORTB and PORTC, as well as PORTA<7:6>, are
designed to drive higher current loads, such as LEDs.
PORTD, PORTE and PORTJ are capable of driving
digital circuits associated with external memory
devices; they can also drive LEDs, but only those with
smaller current requirements. PORTF, PORTG and
PORTH, along with PORTA<5:0>, have the lowest
drive level, but are capable of driving normal digital
circuit loads with a high input impedance.
Data
Bus
WR LAT
WR TRIS
RD PORT
Data Latch
TRIS Latch
RD TRIS
Input
Buffer
I/O pin(1)
QD
CK
QD
CK
EN
QD
EN
RD LAT
or PORT
Port or Pin Tolerated
Input Description
PORTA<7:0> VDD Only VDD input levels
tolerated.
PORTC<1:0>
PORTF<6:1>
PORTH<7:4>(1)
PORTB<7:0> 5.5V Tolerates input levels
above VDD, useful for
most standard logic.
PORTC<7:2>
PORTD<7:0>
PORTE<7:0>
PORTF<7>
PORTG<4:0>
PORTH<3:0>(1)
PORTJ<7:0>(1)
Note 1: These ports are not available on 64-pin
devices.
PIC18F87J11 FAMILY
DS39778C-page 128 Preliminary © 2008 Microchip Technology Inc.
Table 10-2 summarizes the output capabilities of the
ports. Refer to the “Absolute Maximum Ratings” in
Section 27.0 “Electrical Characteristics” for more
details.
TABLE 10-2: OUTPUT DRIVE LEVELS
10.1.3 PULL-UP CONFIGURATION
Four of the I/O ports (PORTB, PORTD, PORTE and
PORTJ) implement configurable weak pull-ups on all
pins. These are internal pull-ups that allow floating
digital input signals to be pulled to a consistent level,
without the use of external resistors.
The pull-ups are enabled with a single bit for each of the
ports: RBPU (INTCON2<7>) for PORTB, and RDPU,
REPU and RJPU (PORTG<7:5>) for the other ports.
10.1.4 OPEN-DRAIN OUTPUTS
The output pins for several peripherals are also
equipped with a configurable, open-drain output option.
This allows the peripherals to communicate with
external digital logic operating at a higher voltage level,
without the use of level translators.
The open-drain option is implemented on port pins spe-
cifically associated with the data and clock outputs of
the EUSARTs, the MSSP modules (in SPI mode) and
the CCP and ECCP modules. It is selectively enabled
by setting the open-drain control bit for the correspond-
ing module in the ODCON registers (Register 10-1,
Register 10-2 and Register 10-3). Their configuration
is discussed in more detail with the individual port
where these peripherals are multiplexed.
The ODCON registers all reside in the SFR configuration
space and share the same SFR addresses as the Timer1
registers (see
Section 5.3.4.1 “Shared Address SFRs”
for more details). The ODCON registers are accessed by
setting the ADSHR bit (WDTCON<4>).
When the open-drain option is required, the output pin
must also be tied through an external pull-up resistor
provided by the user to a higher voltage level, up to 5V
on digital only pins (Figure 10-2). When a digital logic
high signal is output, it is pulled up to the higher voltage
level.
FIGURE 10-2: USING THE OPEN-DRAIN
OUTPUT (EUSARTx
SHOWN AS EXAMPLE)
10.1.5 TTL INPUT BUFFER OPTION
Many of the digital I/O ports use Schmitt Trigger (ST)
input buffers. While this form of buffering works well
with many types of input, some applications may
require TTL-level signals to interface with external logic
devices. This is particularly true with the EMB and the
Parallel Master Port (PMP), which are particularly likely
to be interfaced to TTL-level logic or memory devices.
The inputs for the PMP can be optionally configured for
TTL buffers with the PMPTTL bit in the PADCFG1 reg-
ister (Register 10-4). Setting this bit configures all data
and control input pins for the PMP to use TTL buffers.
By default, these PMP inputs use the port’s ST buffers.
As with the ODCON registers, the PADCFG1 register
resides in the SFR configuration space; it shares the
same memory address as the TMR2 register.
PADCFG1 is accessed by setting the ADSHR bit
(WDTCON<4>).
Port Drive Description
PORTA Minimum Intended for indication.
PORTF
PORTG
PORTH(1)
PORTD Medium Sufficient drive levels for
external memory interfacing
as well as indication.
PORTE
PORTJ(1)
PORTB High Suitable for direct LED drive
levels.
PORTC
Note 1: These ports are not available on 64-pin
devices.
TXX
PIC18F87J11
+5V
3.3V
(at logic ‘1’)
3.3V
VDD 5V
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 129
PIC18F87J11 FAMILY
REGISTER 10-1: ODCON1: PERIPHERAL OPEN-DRAIN CONTROL REGISTER 1
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
CCP5OD CCP4OD ECCP3OD ECCP2OD ECCP1OD
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as0
bit 4-3 CCP5OD:CCP4OD: CCPx Open-Drain Output Enable bits
1 = Open-drain output on CCPx pin (Capture/PWM modes) enabled
0 = Open-drain output disabled
bit 2-0 ECCP3OD:ECCP1OD: ECCPx Open-Drain Output Enable bits
1 = Open-drain output on ECCPx pin (Capture mode) enabled
0 = Open-drain output disabled
REGISTER 10-2: ODCON2: PERIPHERAL OPEN-DRAIN CONTROL REGISTER 2
U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0
U2OD U1OD
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-2 Unimplemented: Read as0
bit 1-0 U2OD:U1OD: EUSARTx Open-Drain Output Enable bits
1 = Open-drain output on TXx pin enabled
0 = Open-drain output disabled
REGISTER 10-3: ODCON3: PERIPHERAL OPEN-DRAIN CONTROL REGISTER 3
U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0
SPI2OD SPI1OD
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-2 Unimplemented: Read as0
bit 1-0 SPI2OD:SPI1OD: SPI Open-Drain Output Enable bits
1 = Open-drain output on SDOx pin enabled
0 = Open-drain output disabled
PIC18F87J11 FAMILY
DS39778C-page 130 Preliminary © 2008 Microchip Technology Inc.
10.2 PORTA, TRISA and
LATA Registers
PORTA is an 8-bit wide, bidirectional port. It may func-
tion as a 6-bit or 7-bit port, depending on the oscillator
mode selected. The corresponding Data Direction and
Output Latch registers are TRISA and LATA.
The RA4 pin is multiplexed with the Timer0 module
clock input to become the RA4/T0CKI pin; it is also mul-
tiplexed as the Parallel Master Port data pin (in 80-pin
devices). The other PORTA pins are multiplexed with
the analog VREF+ and VREF- inputs. The operation of
pins, RA<5,3:0>, as A/D Converter inputs is selected
by clearing or setting the appropriate PCFG control bits
in the ANCON0 register.
The RA4/T0CKI pin is a Schmitt Trigger input. All other
PORTA pins have TTL input levels and full CMOS
output drivers.
The TRISA register controls the direction of the PORTA
pins, even when they are being used as analog inputs.
The user must ensure the bits in the TRISA register are
maintained set when using them as analog inputs.
OSC2/CLKO/RA6 and OSC1/CLKI/RA7 normally
serve as the external circuit connections for the
external (primary) oscillator circuit (HS and HSPLL
Oscillator modes), or the external clock input (EC and
ECPLL Oscillator modes). In these cases, RA6 and
RA7 are not available as digital I/O, and their
corresponding TRIS and LAT bits are read as ‘0’.
For INTIO and INTPLL Oscillator modes (FOSC2 Con-
figuration bit is ‘0), either RA7 or both RA6 and RA7
automatically become available as digital I/O, depend-
ing on the oscillator mode selected. When RA6 is not
configured as a digital I/O, in these cases, it provides a
clock output at FOSC/4. A list of the possible configura-
tions for RA6 and RA7, based on oscillator mode, is
provided in Table 10-3. For these pins, the correspond-
ing PORTA, TRISA and LATA bits are only defined
when the pins are configured as I/O.
TABLE 10-3: FUNCTION OF RA7:RA6 IN
INTIO AND INTPLL MODES
EXAMPLE 10-1: INITIALIZING PORTA
REGISTER 10-4: PADCFG1: I/O PAD CONFIGURATION CONTROL REGISTER
U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-0
PMPTTL
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-1 Unimplemented: Read as0
bit 0 PMPTTL: PMP Module TTL Input Buffer Select bit
1 = PMP module uses TTL input buffers
0 = PMP module uses Schmitt Trigger input buffers
Note 1: RA5 (RA5/PMD4/AN4) is multiplexed as
an analog input in all devices and Parallel
Master Port data in 80-pin devices.
2: RA5 and RA3:RA0 are configured as
analog inputs on any Reset and are read
as ‘0’. RA4 is configured as a digital input.
Oscillator Mode
(FOSC2:FOSC0 Configuration) RA6 RA7
INTPLL1 (011) CLKO I/O
INTPLL2 (010) I/O I/O
INTIO1 (001) CLKO I/O
INTIO2 (000) I/O I/O
Legend: CLKO = FOSC/4 clock output;
I/O = digital port.
CLRF PORTA ; Initialize PORTA by
; clearing output
; data latches
CLRF LATA ; Alternate method to
; clear data latches
BSF WDTCON,ADSHR ; Enable write/read to
; the shared SFR
MOVLW 1Fh ; Configure A/D
MOVWF ANCON0 ; for digital inputs
BCF WDTCON,ADSHR ; Disable write/read
; to the shared SFR
MOVLW 0CFh ; Value used to
; initialize
; data direction
MOVWF TRISA ; Set RA<3:0> as inputs,
; RA<5:4> as outputs
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 131
PIC18F87J11 FAMILY
TABLE 10-4: PORTA FUNCTIONS
Pin Name Function TRIS
Setting I/O I/O
Type Description
RA0/AN0 RA0 0O DIG LATA<0> data output; not affected by analog input.
1I TTL PORTA<0> data input; disabled when analog input enabled.
AN0 1I ANA A/D input channel 0. Default input configuration on POR; does not
affect digital output.
RA1/AN1 RA1 0O DIG LATA<1> data output; not affected by analog input.
1I TTL PORTA<1> data input; disabled when analog input enabled.
AN1 1I ANA A/D input channel 1. Default input configuration on POR; does not
affect digital output.
RA2/AN2/VREF-RA2 0O DIG LATA<2> data output; not affected by analog input. Disabled when
CVREF output enabled.
1I TTL PORTA<2> data input. Disabled when analog functions enabled;
disabled when CVREF output enabled.
AN2 1I ANA A/D input channel 2. Default input configuration on POR; not affected
by analog output.
VREF-1I ANA A/D low reference voltage input.
RA3/AN3/VREF+RA3 0O DIG LATA<3> data output; not affected by analog input.
1I TTL PORTA<3> data input; disabled when analog input enabled.
AN3 1I ANA A/D input channel 3. Default input configuration on POR.
VREF+1I ANA A/D high reference voltage input.
RA4/PMD5/
T0CKI/
RA4 0O DIG LATA<4> data output.
1I ST PORTA<4> data input; default configuration on POR.
PMD5(1) xO DIG Parallel Master Port data output.
xI TTL Parallel Master Port data output.
T0CKI xI ST Timer0 clock input.
RA5/PMD4/AN4 RA5 0O DIG LATA<5> data output; not affected by analog input.
1I TTL PORTA<5> data input; disabled when analog input enabled.
PMD4(1) xO DIG Parallel Master Port data output.
xI TTL Parallel Master Port data output.
AN4 1I ANA A/D input channel 4. Default configuration on POR.
OSC2/CLKO/
RA6
OSC2 xO ANA Main oscillator feedback output connection (HS and HSPLL modes).
CLKO xO DIG System cycle clock output, FOSC/4 (EC, ECPLL, INTIO1 and INTPLL1
modes).
RA6 0O DIG LATA<6> data output; disabled when FOSC2 Configuration bit is set.
1I TTL PORTA<6> data input; disabled when FOSC2 Configuration bit is set.
OSC1/CLKI/
RA7
OSC1 xI ANA Main oscillator input connection (HS and HSPLL modes).
CLKI xI ANA Main external clock source input (EC and ECPLL modes).
RA7 0O DIG LATA<7> data output; disabled when FOSC2 Configuration bit is set.
1I TTL PORTA<7> data input; disabled when FOSC2 Configuration bit is set.
Legend: O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Alternate PMP configuration when the PMPMX Configuration bit is ‘0’; available on 80-pin devices only.
PIC18F87J11 FAMILY
DS39778C-page 132 Preliminary © 2008 Microchip Technology Inc.
TABLE 10-5: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
10.3 PORTB, TRISB and
LATB Registers
PORTB is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISB. All pins on
PORTB are digital only and tolerate voltages up to
5.5V.
Each of the PORTB pins has a weak internal pull-up. A
single control bit can turn on all the pull-ups. This is
performed by clearing bit, RBPU (INTCON2<7>). The
weak pull-up is automatically turned off when the port
pin is configured as an output. The pull-ups are
disabled on a Power-on Reset.
Four of the PORTB pins (RB7:RB4) have an
interrupt-on-change feature. Only pins configured as
inputs can cause this interrupt to occur (i.e., any
RB7:RB4 pin configured as an output is excluded from
the interrupt-on-change comparison). The input pins (of
RB7:RB4) are compared with the old value latched on
the last read of PORTB. The “mismatch” outputs of
RB7:RB4 are ORed together to generate the RB Port
Change Interrupt with Flag bit, RBIF (INTCON<0>).
This interrupt can wake the device from
power-managed modes. The user, in the Interrupt
Service Routine, can clear the interrupt in the following
manner:
a) Any read or write of PORTB (except with the
MOVFF (ANY), PORTB instruction). This will
end the mismatch condition.
b) Clear flag bit, RBIF.
A mismatch condition will continue to set flag bit, RBIF.
Reading PORTB will end the mismatch condition and
allow flag bit, RBIF, to be cleared.
The interrupt-on-change feature is recommended for
wake-up on key depression operation and operations
where PORTB is only used for the interrupt-on-change
feature. Polling of PORTB is not recommended while
using the interrupt-on-change feature.
For 80-pin devices, RB3 can be configured as the
alternate peripheral pin for the ECCP2 module and
Enhanced PWM output 2A by clearing the CCP2MX
Configuration bit. This applies only to 80-pin devices
operating in Extended Microcontroller mode. If the
device is in Microcontroller mode, the alternate
assignment for ECCP2 is RE7. As with other ECCP2
configurations, the user must ensure that the TRISB<3>
bit is set appropriately for the intended operation. Ports,
RB1, RB2, RB3, RB4 and RB5, are multiplexed with
the Parallel Master Port address.
EXAMPLE 10-2: INITIALIZING PORTB
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
PORTA RA7(1) RA6(1) RA5 RA4 RA3 RA2 RA1 RA0 59
LATA LATA7(1) LATA6(1) LATA5 LATA4 LATA3 LATA2 LATA1 LATA0 58
TRISA TRISA7(1) TRISA6(1) TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 58
ANCON0(2) PCFG7 PCFG6 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 57
Legend: = unimplemented, read as ‘0’. Shaded cells are not used by PORTA.
Note 1: Implemented only in specific oscillator modes (FOSC2 Configuration bit = 0); otherwise read as ‘0’.
2: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
CLRF PORTB ; Initialize PORTB by
; clearing output
; data latches
CLRF LATB ; Alternate method to clear
; output data latches
MOVLW 0CFh ; Value used to initialize
; data direction
MOVWF TRISB ; Set RB<3:0> as inputs
; RB<5:4> as outputs
; RB<7:6> as inputs
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 133
PIC18F87J11 FAMILY
TABLE 10-6: PORTB FUNCTIONS
Pin Name Function TRIS
Setting I/O I/O
Type Description
RB0/INT0/FLT0 RB0 0O DIG LATB<0> data output.
1I TTL PORTB<0> data input; weak pull-up when RBPU bit is cleared.
INT0 1I ST External interrupt 0 input.
FLT0 1I ST Enhanced PWM Fault input (ECCP1 module); enabled in software.
RB1/INT1/
PMA4
RB1 0O DIG LATB<1> data output.
1I TTL PORTB<1> data input; weak pull-up when RBPU bit is cleared.
INT1 1I ST External interrupt 1 input.
PMA4 xO Parallel Master Port address out.
RB2/INT2/
PMA3
RB2 0O DIG LATB<2> data output.
1I TTL PORTB<2> data input; weak pull-up when RBPU bit is cleared.
INT2 1I ST External interrupt 2 input.
PMA3 xO Parallel Master Port address out.
RB3/INT3/
PMA2/ECCP2/
P2A
RB3 0O DIG LATB<3> data output.
1I TTL PORTB<3> data input; weak pull-up when RBPU bit is cleared.
INT3 1I ST External interrupt 3 input.
PMA2 xO Parallel Master Port address out.
ECCP2(1) 0O DIG ECCP2 compare output and CCP2 PWM output; takes priority over port
data.
1I ST ECCP2 capture input.
P2A(1) 0O DIG ECCP2 Enhanced PWM output, channel A. May be configured for tri-state
during Enhanced PWM shutdown events. Takes priority over port data.
RB4/KBI0/
PMA1
RB4 0O DIG LATB<4> data output.
1I TTL PORTB<4> data input; weak pull-up when RBPU bit is cleared.
KBI0 I TTL Interrupt-on-pin change.
PMA1 xO Parallel Master Port address out.
RB5/KBI1/
PMA0
RB5 0O DIG LATB<5> data output.
1I TTL PORTB<5> data input; weak pull-up when RBPU bit is cleared.
KBI1 I TTL Interrupt-on-pin change.
PMA0 xO Parallel Master Port address out.
RB6/KBI2/PGC RB6 0O DIG LATB<6> data output.
1I TTL PORTB<6> data input; weak pull-up when RBPU bit is cleared.
KBI2 1I TTL Interrupt-on-pin change.
PGC xI ST Serial execution (ICSP™) clock input for ICSP and ICD operation.(2)
RB7/KBI3/PGD RB7 0O DIG LATB<7> data output.
1I TTL PORTB<7> data input; weak pull-up when RBPU bit is cleared.
KBI3 1I TTL Interrupt-on-pin change.
PGD xO DIG Serial execution data output for ICSP and ICD operation.(2)
xI ST Serial execution data input for ICSP and ICD operation.(2)
Legend: O = Output, I = Input, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Alternate assignment for ECCP2/P2A when the CCP2MX Configuration bit is cleared (Extended Microcontroller mode,
80-pin devices only). Default assignment is RC1.
2: All other pin functions are disabled when ICSP™ or ICD is enabled.
PIC18F87J11 FAMILY
DS39778C-page 134 Preliminary © 2008 Microchip Technology Inc.
TABLE 10-7: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
10.4 PORTC, TRISC and
LATC Registers
PORTC is an 8-bit wide, bidirectional port. Only
PORTC pins, RC2 through RC7, are digital only pins
and can tolerate input voltages up to 5.5V.
PORTC is multiplexed with ECCP, MSSP and EUSART
peripheral functions (Table 10-8). The pins have
Schmitt Trigger input buffers. The pins for ECCP, SPI
and EUSART are also configurable for open-drain out-
put whenever these functions are active. Open-drain
configuration is selected by setting the SPIxOD,
ECCPxOD, and UxOD control bits in the ODCON reg-
isters (see Section 10.1.3 “Pull-up Configuration”
for more information).
RC1 is normally configured as the default peripheral
pin for the ECCP2 module. Assignment of ECCP2 is
controlled by Configuration bit, CCP2MX (default state,
CCP2MX = 1).
When enabling peripheral functions, care should be
taken in defining TRIS bits for each PORTC pin. Some
peripherals override the TRIS bit to make a pin an output,
while other peripherals override the TRIS bit to make a
pin an input. The user should refer to the corresponding
peripheral section for the correct TRIS bit settings.
The contents of the TRISC register are affected by
peripheral overrides. Reading TRISC always returns
the current contents, even though a peripheral device
may be overriding one or more of the pins.
EXAMPLE 10-3: INITIALIZING PORTC
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 59
LATB LATB7 LATB6 LATB5 LATB4 LATB3 LATB2 LATB1 LATB0 58
TRISB TRISB7 TRISB6 TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 58
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP 55
INTCON3 INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF 55
Legend: Shaded cells are not used by PORTB.
Note: These pins are configured as digital inputs
on any device Reset.
CLRF PORTC ; Initialize PORTC by
; clearing output
; data latches
CLRF LATC ; Alternate method to clear
; output data latches
MOVLW 0CFh ; Value used to initialize
; data direction
MOVWF TRISC ; Set RC<3:0> as inputs
; RC<5:4> as outputs
; RC<7:6> as inputs
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 135
PIC18F87J11 FAMILY
TABLE 10-8: PORTC FUNCTIONS
Pin Name Function TRIS
Setting I/O I/O
Type Description
RC0/T1OSO/
T13CKI
RC0 0O DIG LATC<0> data output.
1I ST PORTC<0> data input.
T1OSO xO ANA Timer1 oscillator output; enabled when Timer1 oscillator enabled. Disables
digital I/O.
T13CKI 1I ST Timer1/Timer3 counter input.
RC1/T1OSI/
ECCP2/P2A
RC1 0O DIG LATC<1> data output.
1I ST PORTC<1> data input.
T1OSI xI ANA Timer1 oscillator input; enabled when Timer1 oscillator enabled. Disables
digital I/O.
ECCP2(1) 0O DIG ECCP2 compare output and ECCP2 PWM output; takes priority over port data.
1I ST ECCP2 capture input.
P2A(1) 0O DIG ECCP2 Enhanced PWM output, channel A. May be configured for tri-state
during Enhanced PWM shutdown events. Takes priority over port data.
RC2/ECCP1/
P1A
RC2 0O DIG LATC<2> data output.
1I ST PORTC<2> data input.
ECCP1 0O DIG ECCP1 compare output and ECCP1 PWM output; takes priority over port data.
1I ST ECCP1 capture input.
P1A 0O DIG ECCP1 Enhanced PWM output, channel A. May be configured for tri-state
during Enhanced PWM shutdown events. Takes priority over port data.
RC3/SCK1/
SCL1
RC3 0O DIG LATC<3> data output.
1I ST PORTC<3> data input.
SCK1 0O DIG SPI clock output (MSSP1 module); takes priority over port data.
1I ST SPI clock input (MSSP1 module).
SCL1 0ODIGI
2C™ clock output (MSSP1 module); takes priority over port data.
1ISTI
2C clock input (MSSP1 module); input type depends on module setting.
RC4/SDI1/
SDA1
RC4 0O DIG LATC<4> data output.
1I ST PORTC<4> data input.
SDI1 1I ST SPI data input (MSSP1 module).
SDA1 1ODIGI
2C data output (MSSP1 module); takes priority over port data.
1ISTI
2C data input (MSSP1 module); input type depends on module setting.
RC5/SDO1 RC5 0O DIG LATC<5> data output.
1I ST PORTC<5> data input.
SDO1 0O DIG SPI data output (MSSP1 module); takes priority over port data.
RC6/TX1/CK1 RC6 0O DIG LATC<6> data output.
1I ST PORTC<6> data input.
TX1 1O DIG Synchronous serial data output (EUSART1 module); takes priority over port data.
CK1 1O DIG Synchronous serial data input (EUSART1 module). User must configure as
an input.
1I ST Synchronous serial clock input (EUSART1 module).
RC7/RX1/DT1 RC7 0O DIG LATC<7> data output.
1I ST PORTC<7> data input.
RX1 1I ST Asynchronous serial receive data input (EUSART1 module).
DT1 1O DIG Synchronous serial data output (EUSART1 module); takes priority over
port data.
1I ST Synchronous serial data input (EUSART1 module). User must configure as
an input.
Legend: O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Default assignment for ECCP2/P2A when CCP2MX Configuration bit is set.
PIC18F87J11 FAMILY
DS39778C-page 136 Preliminary © 2008 Microchip Technology Inc.
TABLE 10-9: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
10.5 PORTD, TRISD and
LATD Registers
PORTD is an 8-bit wide, bidirectional port. All pins on
PORTD are digital only and tolerate voltages up to
5.5V.
All pins on PORTD are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
On 80-pin devices, PORTD is multiplexed with the
system bus as part of the external memory interface.
I/O port and other functions are only available when the
interface is disabled by setting the EBDIS bit
(MEMCON<7>). When the interface is enabled,
PORTD is the low-order byte of the multiplexed
address/data bus (AD7:AD0). The TRISD bits are also
overridden.
PORTD is also multiplexed with the data functions of
the Parallel Master Port data. In this mode, Parallel
Master Port takes priority over the other digital I/O (but
not the external memory bus). This multiplexing is
available when PMPMX = 1. When the Parallel Master
Port is active, the input buffers are TTL. For more
information, refer to Section 11.0 “Parallel Master
Port”.
Each of the PORTD pins has a weak internal pull-up.
This is performed by clearing bit RDPU (PORTG<7>).
The weak pull-up is automatically turned off when the
port pin is configured as an output. The pull-ups are
disabled on all device Resets.
EXAMPLE 10-4: INITIALIZING PORTD
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 59
LATC LATC7 LATBC6 LATC5 LATCB4 LATC3 LATC2 LATC1 LATC0 58
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 58
Note: These pins are configured as digital inputs
on any device Reset.
CLRF PORTD ; Initialize PORTD by
; clearing output
; data latches
CLRF LATD ; Alternate method to clear
; output data latches
MOVLW 0CFh ; Value used to initialize
; data direction
MOVWF TRISD ; Set RD<3:0> as inputs
; RD<5:4> as outputs
; RD<7:6> as inputs
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 137
PIC18F87J11 FAMILY
TABLE 10-10: PORTD FUNCTIONS
Pin Name Function TRIS
Setting I/O I/O
Type Description
RD0/AD0/
PMD0
RD0 0O DIG LATD<0> data output.
1I ST PORTD<0> data input.
AD0(2) xO DIG External memory interface, address/data bit 0 output.(1)
xI TTL External memory interface, data bit 0 input.(1)
PMD0(3) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
RD1/AD1/
PMD1
RD1 0O DIG LATD<1> data output.
1I ST PORTD<1> data input.
AD1(2) xO DIG External memory interface, address/data bit 1 output.(1)
xI TTL External memory interface, data bit 1 input.(1)
PMD1(3) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
RD2/AD2/
PMD2
RD2 0O DIG LATD<2> data output.
1I ST PORTD<2> data input.
AD2(2) xO DIG External memory interface, address/data bit 2 output.(1)
xI TTL External memory interface, data bit 2 input.(1)
PMD2(3) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
RD3/AD3/
PMD3
RD3 0O DIG LATD<3> data output.
1I ST PORTD<3> data input.
AD3(2) xO DIG External memory interface, address/data bit 3 output.(1)
xI TTL External memory interface, data bit 3 input.(1)
PMD3(3) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
RD4/AD4/
PMD4/SDO2
RD4 0O DIG LATD<4> data output.
1I ST PORTD<4> data input.
AD4(2) xO DIG External memory interface, address/data bit 4 output.(1)
xI TTL External memory interface, data bit 4 input.(1)
PMD4(3) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
SDO2 0O DIG SPI data output (MSSP2 module); takes priority over port data.
RD5/AD5/
PMD5/SDI2/
SDA2
RD5 0O DIG LATD<5> data output.
1I ST PORTD<5> data input.
AD5(2) xO DIG External memory interface, address/data bit 5 output.(1)
xI TTL External memory interface, data bit 5 input.(1)
PMD5(3) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
SDI2 1I ST SPI data input (MSSP2 module).
SDA2 1ODIGI
2C™ data output (MSSP2 module); takes priority over port data.
1ISTI
2C data input (MSSP2 module); input type depends on module
setting.
Legend: O = Output, I = Input, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: External memory interface I/O takes priority over all other digital and PMP I/O.
2: Available on 80-pin devices only.
3: Default configuration for PMP (PMPMX Configuration bit = 1).
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DS39778C-page 138 Preliminary © 2008 Microchip Technology Inc.
TABLE 10-11: SUMMARY OF REGISTERS ASSOCIATED WITH PORTD
RD6/AD6/
PMD6/SCK2/
SCL2
RD6 0O DIG LATD<6> data output.
1I ST PORTD<6> data input.
AD6(2) xO DIG-3 External memory interface, address/data bit 6 output.(1)
xI TTL External memory interface, data bit 6 input.(1)
PMD6(3) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
SCK2 0O DIG SPI clock output (MSSP2 module); takes priority over port data.
1I ST SPI clock input (MSSP2 module).
SCL2 0ODIGI
2C™ clock output (MSSP2 module); takes priority over port data.
1ISTI
2C clock input (MSSP2 module); input type depends on module
setting.
RD7/AD7/
PMD7/SS2
RD7 0O DIG LATD<7> data output.
1I ST PORTD<7> data input.
AD7(2) xO DIG External memory interface, address/data bit 7 output.(1)
xI TTL External memory interface, data bit 7 input.(1)
PMD7(3) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
SS2 xI TTL Slave select input for MSSP2 module.
TABLE 10-10: PORTD FUNCTIONS (CONTINUED)
Pin Name Function TRIS
Setting I/O I/O
Type Description
Legend: O = Output, I = Input, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: External memory interface I/O takes priority over all other digital and PMP I/O.
2: Available on 80-pin devices only.
3: Default configuration for PMP (PMPMX Configuration bit = 1).
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
PORTD RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 59
LATD LATD7 LATD6 LATD5 LATD4 LATD3 LATD2 LATD1 LATD0 58
TRISD TRISD7 TRISD6 TRISD5 TRISD4TRISD3TRISD2TRISD1TRISD0 58
PORTG RDPU REPU RJPU(1) RG4 RG3 RG2 RG1 RG0 59
Legend: Shaded cells are not used by PORTD.
Note 1: Unimplemented on 64-pin devices, read as0’.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 139
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10.6 PORTE, TRISE and
LATE Registers
PORTE is an 8-bit wide, bidirectional port. All pins on
PORTE are digital only and tolerate voltages up to
5.5V.
All pins on PORTE are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
On 80-pin devices, PORTE is multiplexed with the
system bus as part of the external memory interface.
I/O port and other functions are only available when the
interface is disabled, by setting the EBDIS bit
(MEMCON<7>). When the interface is enabled,
PORTE is the high-order byte of the multiplexed
address/data bus (AD15:AD8). The TRISE bits are also
overridden.
Each of the PORTE pins has a weak internal pull-up. A
single control bit can turn off all the pull-ups. This is
performed by clearing bit REPU (PORTG<6>). The
weak pull-up is automatically turned off when the port
pin is configured as an output. The pull-ups are
disabled on any device Reset.
PORTE is also multiplexed with Enhanced PWM
outputs B and C for ECCP1 and ECCP3 and outputs B,
C and D for ECCP2. For all devices, their default
assignments are on PORTE<6:0>. On 80-pin devices,
the multiplexing for the outputs of ECCP1 and ECCP3
is controlled by the ECCPMX Configuration bit.
Clearing this bit reassigns the P1B/P1C and P3B/P3C
outputs to PORTH.
For devices operating in Microcontroller mode, pin RE7
can be configured as the alternate peripheral pin for the
ECCP2 module and Enhanced PWM output 2A. This is
done by clearing the CCP2MX Configuration bit.
PORTE is also multiplexed with the Parallel Master
Port address lines. When PMPMX = 0, RE1 and RE0
are multiplexed with the control signals PMWR and
PMRD.
RE3 can also be configured as the Reference Clock
Output (REFO) from the system clock. For further
details, refer to Section 2.6 “Reference Clock
Output”.
EXAMPLE 10-5: INITIALIZING PORTE
Note: These pins are configured as digital inputs
on any device Reset.
CLRF PORTE ; Initialize PORTE by
; clearing output
; data latches
CLRF LATE ; Alternate method to clear
; output data latches
MOVLW 03h ; Value used to initialize
; data direction
MOVWF TRISE ; Set RE<1:0> as inputs
; RE<7:2> as outputs
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DS39778C-page 140 Preliminary © 2008 Microchip Technology Inc.
TABLE 10-12: PORTE FUNCTIONS
Pin Name Function TRIS
Setting I/O I/O
Type Description
RE0/AD8/
PMRD/P2D
RE0 0O DIG LATE<0> data output.
1I ST PORTE<0> data input.
AD8(3) xO DIG External memory interface, address/data bit 8 output.(2)
xI TTL External memory interface, data bit 8 input.(2)
PMRD(5) xO DIG Parallel Master Port read strobe pin.
xI TTL Parallel Master Port read pin.
P2D 0O DIG ECCP2 Enhanced PWM output, channel D; takes priority over port
and PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
RE1/AD9/
PMWR/P2C
RE1 0O DIG LATE<1> data output.
1I ST PORTE<1> data input.
AD9(3) xO DIG External memory interface, address/data bit 9 output.(2)
xI TTL External memory interface, data bit 9 input.(2)
PMWR(5) xO DIG Parallel Master Port write strobe pin.
xI TTL Parallel Master Port write pin.
P2C 0O DIG ECCP2 Enhanced PWM output, channel C; takes priority over port
and PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
RE2/AD10/
PMBE/P2B
RE2 0O DIG LATE<2> data output.
1I ST PORTE<2> data input.
AD10(3) xO DIG External memory interface, address/data bit 10 output.(2)
xI TTL External memory interface, data bit 10 input.(2)
PMBE(5) xO DIG Parallel Master Port byte enable.
P2B 0O DIG ECCP2 Enhanced PWM output, channel B; takes priority over port and
PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
RE3/AD11/
PMA13/P3C/
REFO
RE3 0O DIG LATE<3> data output.
1I ST PORTE<3> data input.
AD11(3) xO DIG External memory interface, address/data bit 11 output.(2)
xI TTL External memory interface, data bit 11 input.(2)
PMA13 xO DIG Parallel Master Port address.
P3C(1) 0O DIG ECCP3 Enhanced PWM output, channel C; takes priority over port
and PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
REFO xO DIG Reference output clock.
RE4/AD12/
PMA12/P3B
RE4 0O DIG LATE<4> data output.
1I ST PORTE<4> data input.
AD12(3) xO DIG External memory interface, address/data bit 12 output.(2)
xI TTL External memory interface, data bit 12 input.(2)
PMA12 xO DIG Parallel Master Port address.
P3B(1) 0O DIG ECCP3 Enhanced PWM output, channel B; takes priority over port and
PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
Legend: O = Output, I = Input, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Default assignments for P1B/P1C and P3B/P3C when ECCPMX Configuration bit is set (80-pin devices only).
2: External memory interface I/O takes priority over all other digital and PMP I/O.
3: Available on 80-pin devices only.
4: Alternate assignment for ECCP2/P2A when ECCP2MX Configuration bit is cleared (all devices in Microcontroller mode).
5: Default configuration for PMP (PMPMX Configuration bit = 1).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 141
PIC18F87J11 FAMILY
TABLE 10-13: SUMMARY OF REGISTERS ASSOCIATED WITH PORTE
RE5/AD13/
PMA11/P1C
RE5 0O DIG LATE<5> data output.
1I ST PORTE<5> data input.
AD13(3) xO DIG External memory interface, address/data bit 13 output.(2)
xI TTL External memory interface, data bit 13 input.(2)
PMA11 xO DIG Parallel Master Port address.
P1C(1) 0O DIG ECCP1 Enhanced PWM output, channel C; takes priority over port
and PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
RE6/AD14/
PMA10/P1B
RE6 0O DIG LATE<6> data output.
1I ST PORTE<6> data input.
AD14(3) xO DIG External memory interface, address/data bit 14 output.(2)
xI TTL External memory interface, data bit 14 input.(2)
PMA10 xO DIG Parallel Master Port address.
P1B(1) 0O DIG ECCP1 Enhanced PWM output, channel B; takes priority over port and
PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
RE7/AD15/
PMA9/ECCP2/
P2A
RE7 0O DIG LATE<7> data output.
1I ST PORTE<7> data input.
AD15(3) xO DIG External memory interface, address/data bit 15 output.(2)
xI TTL External memory interface, data bit 15 input.(2)
PMA9 xO DIG Parallel Master Port address.
ECCP2(4) 0O DIG ECCP2 compare output and ECCP2 PWM output; takes priority over
port data.
1I ST ECCP2 capture input.
P2A(4) 0O DIG ECCP2 Enhanced PWM output, channel A; takes priority over port and
PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
TABLE 10-12: PORTE FUNCTIONS (CONTINUED)
Pin Name Function TRIS
Setting I/O I/O
Type Description
Legend: O = Output, I = Input, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Default assignments for P1B/P1C and P3B/P3C when ECCPMX Configuration bit is set (80-pin devices only).
2: External memory interface I/O takes priority over all other digital and PMP I/O.
3: Available on 80-pin devices only.
4: Alternate assignment for ECCP2/P2A when ECCP2MX Configuration bit is cleared (all devices in Microcontroller mode).
5: Default configuration for PMP (PMPMX Configuration bit = 1).
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
PORTE RE7 RE6 RE5 RE4 RE3 RE2 RE1 RE0 59
LATE LATE7 LATE6 LATE5 LATE4 LATE3 LATE2 LATE1 LATE0 58
TRISE TRISE7 TRISE6 TRISE5 TRISE4 TRISE3 TRISE2 TRISE1 TRISE0 58
PORTG RDPU REPU RJPU(1) RG4 RG3 RG2 RG1 RG0 59
Legend: Shaded cells are not used by PORTE.
Note 1: Unimplemented on 64-pin devices, read as ‘0’.
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DS39778C-page 142 Preliminary © 2008 Microchip Technology Inc.
10.7 PORTF, LATF and TRISF Registers
PORTF is a 7-bit wide, bidirectional port. Only pin 7 of
PORTF has no analog input; it is the only pin that can
tolerate voltages up to 5.5V.
All pins on PORTF are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
PORTF is multiplexed with analog peripheral functions.
RF1 through RF6 may also be used as analog input
channels for the A/D Converter. All pins may be used as
comparator inputs or outputs by setting the appropriate
bits in the CMCON register. To use RF<6:3> as digital
inputs, it is also necessary to turn off the comparators.
When Configuration bit, PMPMX = 0, PORTF is
multiplexed with the Parallel Master Port data. This
multiplexing is available only in 80-pin devices.
EXAMPLE 10-6: INITIALIZING PORTF
Note 1: On device Resets, pins RF6:RF1 are
configured as analog inputs and are read
as ‘0’.
2: To configure PORTF as digital I/O, set the
corresponding bits in ANCON0 and
ANCON1.
CLRF PORTF ; Initialize PORTF by
; clearing output
; data latches
CLRF LATF ; Alternate method to
; clear output latches
BSF WDTCON,ADSHR ; Enable write/read to
; the shared SFR
MOVLW C0h ; make RF1:RF2 digital
MOVWF ANCON0 ;
MOVLW 0Fh ; make RF<6:3> digital
MOVWF ANCON1 ;
BCF WDTCON,ADSHR ; Disable write/read to
; the shared SFR
MOVLW CEh ;
MOVWF TRISF ; Set RF5:RF4 as outputs,
; RF<7:6>,<3:1> as inputs
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 143
PIC18F87J11 FAMILY
TABLE 10-14: PORTF FUNCTIONS
Pin Name Function TRIS
Setting I/O I/O
Type Description
RF1/AN6/
C2OUT
RF1 0O DIG LATF<1> data output; not affected by analog input.
1I ST PORTF<1> data input; disabled when analog input enabled.
AN6 1I ANA A/D input channel 6. Default configuration on POR.
C2OUT xO DIG Comparator 2 output.
RF2/PMA5/
AN7//C1OUT
RF2 0O DIG LATF<2> data output; not affected by analog input.
1I ST PORTF<2> data input; disabled when analog input enabled.
PMA5 xO DIG Parallel Master Port address.
AN7 1I ANA A/D input channel 7. Default configuration on POR.
C1OUT xO DIG Comparator 1 output.
RF3/AN8/
C2INB
RF3 0O DIG LATF<3> data output; not affected by analog input.
1I ST PORTF<3> data input; disabled when analog input enabled.
AN8 1I ANA A/D input channel 8. Default configuration on POR.
C2INB xI ANA Comparator 2 input B.
RF4/AN9/
C2INA
RF4 0O DIG LATF<4> data output; not affected by analog input.
1I ST PORTF<4> data input; disabled when analog input enabled.
AN9 1I ANA A/D input channel 9. Default configuration on POR.
C2INA xI ANA Comparator 2 input A.
RF5/PMD2/
AN10/C1INB/
CVREF
RF5 0O DIG LATF<5> data output; not affected by analog input. Disabled when
CVREF output enabled.
1I ST PORTF<5> data input; disabled when analog input enabled. Disabled
when CVREF output enabled.
PMD2(1) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
AN10 1I ANA A/D input channel 10 and Comparator C1+ input. Default input
configuration on POR.
C1INB xI ANA Comparator 1 input B.
CVREF xO ANA Comparator voltage reference output. Enabling this feature disables
digital I/O.
RF6/PMD1/
AN11/C1INA
RF6 0O DIG LATF<6> data output; not affected by analog input.
1I ST PORTF<6> data input; disabled when analog input enabled.
PMD1(1) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
AN11 1I ANA A/D input channel 11 and comparator C1- input. Default input
configuration on POR; does not affect digital output.
C1INA xI ANA Comparator 1 input A.
RF7/PMD0/
SS1
RF7 0O DIG LATF<7> data output.
1I ST PORTF<7> data input.
PMD0(1) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
SS1 1I TTL Slave select input for MSSP1 module.
Legend: O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Alternate PMP configuration when the PMPMX Configuration bit = 0; available on 80-pin devices only.
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DS39778C-page 144 Preliminary © 2008 Microchip Technology Inc.
TABLE 10-15: SUMMARY OF REGISTERS ASSOCIATED WITH PORTF
10.8 PORTG, TRISG and
LATG Registers
PORTG is a 5-bit wide, bidirectional port. All pins on
PORTG are digital only and tolerate voltages up to
5.5V.
PORTG is multiplexed with EUSART2 functions
(Table 10-16). PORTG pins have Schmitt Trigger input
buffers. PORTG is also multiplexed with address and
control functions of the Parallel Master Port.
When enabling peripheral functions, care should be
taken in defining TRIS bits for each PORTG pin. Some
peripherals override the TRIS bit to make a pin an
output, while other peripherals override the TRIS bit to
make a pin an input. The user should refer to the
corresponding peripheral section for the correct TRIS
bit settings. The pin override value is not loaded into
the TRIS register. This allows read-modify-write of the
TRIS register without concern due to peripheral
overrides.
Although the port itself is only five bits wide,
PORTG<7:5> bits are still implemented. These are
used to control the weak pull-ups on the I/O ports asso-
ciated with the external memory bus (PORTD, PORTE
and PORTJ). Setting these bits enables the pull-ups.
Since these are control bits and are not associated with
port I/O, the corresponding TRISG and LATG bits are
not implemented.
EXAMPLE 10-7: INITIALIZING PORTG
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
PORTF RF7 RF6 RF5 RF4 RF3 RF2 RF1 —59
LATF LATF7 LATF6 LATF5 LATF4 LATF3 LATF2 LATF1 —58
TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 —58
ANCON0(1) PCFG7 PCFG6 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 57
ANCON1(1) PCFG15 PCFG14 PCFG13 PCFG12 PCFG11 PCFG10 PCFG9 PCFG8 57
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTF.
Note 1: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
CLRF PORTG ; Initialize PORTG by
; clearing output
; data latches
CLRF LATG ; Alternate method to clear
; output data latches
MOVLW 04h ; Value used to initialize
; data direction
MOVWF TRISG ; Set RG1:RG0 as outputs
; RG2 as input
; RG4:RG3 as outputs
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 145
PIC18F87J11 FAMILY
TABLE 10-16: PORTG FUNCTIONS
Pin Name Function TRIS
Setting I/O I/O
Type Description
RG0/PMA8/
ECCP3/P3A
RG0 0O DIG LATG<0> data output.
1I ST PORTG<0> data input.
PMA8 xO DIG Parallel Master Port address.
ECCP3 O DIG ECCP3 compare and PWM output; takes priority over port data.
I ST ECCP3 capture input.
P3A 0O DIG ECCP3 Enhanced PWM output, channel A; takes priority over port and
PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
RG1/PMA7/
TX2/CK2
RG1 0O DIG LATG<1> data output.
1I ST PORTG<1> data input.
PMA7 xO DIG Parallel Master Port address.
TX2 1O DIG Synchronous serial data output (EUSART2 module); takes priority over
port data.
CK2 1O DIG Synchronous serial data input (EUSART2 module). User must configure
as an input.
1I ST Synchronous serial clock input (EUSART2 module).
RG2/PMA6/
RX2/DT2
RG2 0O DIG LATG<2> data output.
1I ST PORTG<2> data input.
PMA6 xO DIG Parallel Master Port address.
RX2 1I ST Asynchronous serial receive data input (EUSART2 module).
DT2 1O DIG Synchronous serial data output (EUSART2 module); takes priority over
port data.
1I ST Synchronous serial data input (EUSART2 module). User must configure
as an input.
RG3/PMCS1/
CCP4/P3D
RG3 0O DIG LATG<3> data output.
1I ST PORTG<3> data input.
PMCS1 xO DIG Parallel Master Port address chip select 1
xI TTL Parallel Master Port address chip select 1 in.
CCP4 0O DIG CCP4 compare output and CCP4 PWM output; takes priority over port data.
1I ST CCP4 capture input.
P3D 0O DIG ECCP3 Enhanced PWM output, channel D; takes priority over port and
PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
RG4/PMCS2/
CCP5/P1D
RG4 0O DIG LATG<4> data output.
1I ST PORTG<4> data input.
PMCS2 xO DIG Parallel Master Port address chip select 2
CCP5 0O DIG CCP5 compare output and CCP5 PWM output; takes priority over port data.
1I ST CCP5 capture input.
P1D 0O DIG ECCP1 Enhanced PWM output, channel D; takes priority over port and
PMP data. May be configured for tri-state during Enhanced PWM
shutdown events.
Legend: O = Output, I = Input, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
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DS39778C-page 146 Preliminary © 2008 Microchip Technology Inc.
TABLE 10-17: SUMMARY OF REGISTERS ASSOCIATED WITH PORTG
10.9 PORTH, LATH and
TRISH Registers
PORTH is an 8-bit wide, bidirectional I/O port. PORTH
pins <3:0> are digital only and tolerate voltages up to
5.5V.
All pins on PORTH are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
When the external memory interface is enabled, four of
the PORTH pins function as the high-order address
lines for the interface. The address output from the
interface takes priority over other digital I/O. The
corresponding TRISH bits are also overridden. PORTH
pins, RH4 through RH7, are multiplexed with analog
converter inputs. The operation of these pins as analog
inputs is selected by clearing or setting the
corresponding bits in the ANCON1 register. RH2 to
RH6 are multiplexed with the Parallel Master Port and
RH4 to RH6 are multiplexed as comparator inputs.
PORTH can also be configured as the alternate
Enhanced PWM output channels B and C for the
ECCP1 and ECCP3 modules. This is done by clearing
the ECCPMX Configuration bit.
EXAMPLE 10-8: INITIALIZING PORTH
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values on
Page:
PORTG RDPU REPU RJPU(1) RG4 RG3 RG2 RG1 RG0 59
LATG LATG4 LATG3 LATG2 LATG1 LATG0 58
TRISG TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 58
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTG.
Note 1: Unimplemented on 64-pin devices, read as0’.
Note: PORTH is available only on 80-pin
devices.
CLRF PORTH ; Initialize PORTH by
; clearing output
; data latches
CLRF LATH ; Alternate method to
; clear output latches
BSF WDTCON,ADSHR ; Enable write/read to
; the shared SFR
MOVLW F0h ; Configure PORTH as
MOVWF ANCON1 ; digital I/O
BCF WDTCON,ADSHR ; Disable write/read to
; the shared SFR
MOVLW 0CFh ; Value used to initialize
; data direction
MOVWF TRISH ; Set RH<3:0> as inputs
; RH<5:4> as outputs
; RH<7:6> as inputs
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 147
PIC18F87J11 FAMILY
TABLE 10-18: PORTH FUNCTIONS
Pin Name Function TRIS
Setting I/O I/O
Type Description
RH0/A16 RH0 0O DIG LATH<0> data output.
1I ST PORTH<0> data input.
A16 xO DIG External memory interface, address line 16. Takes priority over port data.
RH1/A17 RH1 0O DIG LATH<1> data output.
1I ST PORTH<1> data input.
A17 xO DIG External memory interface, address line 17. Takes priority over port data.
RH2/A18/
PMD7
RH2 0O DIG LATH<2> data output.
1I ST PORTH<2> data input.
A18 xO DIG External memory interface, address line 18. Takes priority over port data.
PMD7(2) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
RH3/A19/
PMD6
RH3 0O DIG LATH<3> data output.
1I ST PORTH<3> data input.
A19 xO DIG External memory interface, address line 19. Takes priority over port data.
PMD6(2) xO DIG Parallel Master Port data out.
xI TTL Parallel Master Port data input.
RH4/PMD3/
AN12/P3C/
C2INC
RH4 0O DIG LATH<4> data output.
1I ST PORTH<4> data input.
PMD3(2) xI TTL Parallel Master Port data out.
xO DIG Parallel Master Port data input.
AN12 I ANA A/D input channel 12. Default input configuration on POR; does not affect
digital output.
P3C(1) 0O DIG ECCP3 Enhanced PWM output, channel C; takes priority over port and PMP
data. May be configured for tri-state during Enhanced PWM shutdown events.
C2INC xI ANA Comparator 2 input C.
RH5/PMBE/
AN13/P3B/
C2IND
RH5 0O DIG LATH<5> data output.
1I ST PORTH<5> data input.
PMBE(2) xO DIG Parallel Master Port data byte enable.
AN13 I ANA A/D input channel 13. Default input configuration on POR; does not affect
digital output.
P3B(1) 0O DIG ECCP3 Enhanced PWM output, channel B; takes priority over port and PMP
data. May be configured for tri-state during Enhanced PWM shutdown events.
C2IND xI ANA Comparator 2 input D.
RH6/PMRD/
AN14/P1C/
C1INC
RH6 0O DIG LATH<6> data output.
1I ST PORTH<6> data input.
PMRD(2) xO DIG Parallel Master Port read strobe.
xI TTL Parallel Master Port read in.
AN14 I ANA A/D input channel 14. Default input configuration on POR; does not affect
digital output.
P1C(1) 0O DIG ECCP1 Enhanced PWM output, channel C; takes priority over port and PMP
data. May be configured for tri-state during Enhanced PWM shutdown events.
C1INC xI ANA Comparator 1 input C.
Legend: O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Alternate assignments for P1B/P1C and P3B/P3C when the ECCPMX Configuration bit is cleared. Default assignments
are PORTE<6:3>.
2: Alternate PMP configuration when the PMPMX Configuration bit = 0; available on 80-pin devices only.
PIC18F87J11 FAMILY
DS39778C-page 148 Preliminary © 2008 Microchip Technology Inc.
TABLE 10-19: SUMMARY OF REGISTERS ASSOCIATED WITH PORTH
RH7/PMWR/
AN15/P1B
RH7 0O DIG LATH<7> data output.
1I ST PORTH<7> data input.
PMWR(2) xO DIG Parallel Master Port write strobe.
xI TTL Parallel Master Port write in.
AN15 I ANA A/D input channel 15. Default input configuration on POR; does not affect
digital output.
P1B(1) 0O DIG ECCP1 Enhanced PWM output, channel B; takes priority over port and PMP
data. May be configured for tri-state during Enhanced PWM shutdown events.
TABLE 10-18: PORTH FUNCTIONS (CONTINUED)
Pin Name Function TRIS
Setting I/O I/O
Type Description
Legend: O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Alternate assignments for P1B/P1C and P3B/P3C when the ECCPMX Configuration bit is cleared. Default assignments
are PORTE<6:3>.
2: Alternate PMP configuration when the PMPMX Configuration bit = 0; available on 80-pin devices only.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
PORTH(1) RH7 RH6 RH5 RH4 RH3 RH2 RH1 RH0 58
LATH(1) LATH7 LATH6 LATH5 LATH4 LATH3 LATH2 LATH1 LATH0 59
TRISH(1) TRISH7 TRISH6 TRISH5 TRISH4 TRISH3 TRISH2 TRISH1 TRISH0 58
ANCON1(2) PCFG15 PCFG14 PCFG13 PCFG12 PCFG11 PCFG10 PCFG9 PCFG8 57
Legend: Shaded cells are not used by PORTH.
Note 1: Unimplemented on 64-pin devices, read as0’.
2: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 149
PIC18F87J11 FAMILY
10.10 PORTJ, TRISJ and
LATJ Registers
PORTJ is an 8-bit wide, bidirectional port. All pins on
PORTJ are digital only and tolerate voltages up to 5.5V.
All pins on PORTJ are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
When the external memory interface is enabled, all of
the PORTJ pins function as control outputs for the
interface. This occurs automatically when the interface
is enabled by clearing the EBDIS control bit
(MEMCON<7>). The TRISJ bits are also overridden.
Each of the PORTJ pins has a weak internal pull-up. A
single control bit can turn off all the pull-ups. This is
performed by clearing bit RJPU (PORTG<5>). The
weak pull-up is automatically turned off when the port
pin is configured as an output. The pull-ups are
disabled on any device Reset.
EXAMPLE 10-9: INITIALIZING PORTJ
Note: PORTJ is available only on 80-pin devices.
Note: These pins are configured as digital inputs
on any device Reset.
CLRF PORTJ ; Initialize PORTG by
; clearing output
; data latches
CLRF LATJ ; Alternate method to clear
; output data latches
MOVLW 0CFh ; Value used to initialize
; data direction
MOVWF TRISJ ; Set RJ3:RJ0 as inputs
; RJ5:RJ4 as output
; RJ7:RJ6 as inputs
PIC18F87J11 FAMILY
DS39778C-page 150 Preliminary © 2008 Microchip Technology Inc.
TABLE 10-20: PORTJ FUNCTIONS
TABLE 10-21: SUMMARY OF REGISTERS ASSOCIATED WITH PORTJ
Pin Name Function TRIS
Setting I/O I/O
Type Description
RJ0/ALE RJ0 0O DIG LATJ<0> data output.
1I ST PORTJ<0> data input.
ALE xO DIG External memory interface address latch enable control output; takes
priority over digital I/O.
RJ1/OE RJ1 0O DIG LATJ<1> data output.
1I ST PORTJ<1> data input.
OE xO DIG External memory interface output enable control output; takes priority
over digital I/O.
RJ2/WRL RJ2 0O DIG LATJ<2> data output.
1I ST PORTJ<2> data input.
WRL xO DIG External memory bus write low byte control; takes priority over
digital I/O.
RJ3/WRH RJ3 0O DIG LATJ<3> data output.
1I ST PORTJ<3> data input.
WRH xO DIG External memory interface write high byte control output; takes priority
over digital I/O.
RJ4/BA0 RJ4 0O DIG LATJ<4> data output.
1I ST PORTJ<4> data input.
BA0 xO DIG External memory interface byte address 0 control output; takes priority
over digital I/O.
RJ5/CE RJ5 0O DIG LATJ<5> data output.
1I ST PORTJ<5> data input.
CE xO DIG External memory interface chip enable control output; takes priority
over digital I/O.
RJ6/LB RJ6 0O DIG LATJ<6> data output.
1I ST PORTJ<6> data input.
LB xO DIG External memory interface lower byte enable control output; takes
priority over digital I/O.
RJ7/UB RJ7 0O DIG LATJ<7> data output.
1I ST PORTJ<7> data input.
UB xO DIG External memory interface upper byte enable control output; takes
priority over digital I/O.
Legend: O = Output, I = Input, DIG = Digital Output, ST = Schmitt Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
PORTJ(1) RJ7 RJ6 RJ5 RJ4 RJ3 RJ2 RJ1 RJ0 59
LATJ(1) LATJ7 LATJ6 LATJ5 LATJ4 LATJ3 LATJ2 LATJ1 LATJ0 58
TRISJ(1) TRISJ7 TRISJ6 TRISJ5 TRISJ4 TRISJ3 TRISJ2 TRISJ1 TRISJ0 58
PORTG RDPU REPU RJPU(1) RG4 RG3 RG2 RG1 RG0 59
Legend: Shaded cells are not used by PORTJ.
Note 1: Unimplemented on 64-pin devices, read as0’.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 151
PIC18F87J11 FAMILY
11.0 PARALLEL MASTER PORT
The Parallel Master Port module (PMP) is a parallel,
8-bit I/O module, specifically designed to communicate
with a wide variety of parallel devices, such as commu-
nication peripherals, LCDs, external memory devices
and microcontrollers. Because the interface to parallel
peripherals varies significantly, the PMP is highly
configurable. The PMP module can be configured to
serve as either a Parallel Master Port or as a Parallel
Slave Port.
Key features of the PMP module include:
Up to 16 Programmable Address Lines
Up to Two Chip Select Lines
Programmable Strobe Options
- Individual Read and Write Strobes or;
- Read/Write Strobe with Enable Strobe
Address Auto-Increment/Auto-Decrement
Programmable Address/Data Multiplexing
Programmable Polarity on Control Signals
Legacy Parallel Slave Port Support
Enhanced Parallel Slave Support
- Address Support
- 4-Byte Deep, Auto-Incrementing Buffer
Programmable Wait States
Selectable Input Voltage Levels
FIGURE 11-1: PMP MODULE OVERVIEW
PMA<0>
PMA<14>
PMA<15>
PMBE
PMRD
PMWR
PMD<7:0>
PMENB
PMRD/PMWR
PMCS1
PMA<1>
PMA<13:2>
PMALL
PMALH
PMA<7:0>
PMA<15:8>
PMCS2
EEPROM
Address Bus
Data Bus
Control Lines
PIC18
LCD FIFO
Microcontroller
8-Bit Data
Up to 16-Bit Address
Parallel Master Port
Buffer
PIC18F87J11 FAMILY
DS39778C-page 152 Preliminary © 2008 Microchip Technology Inc.
11.1 Module Registers
The PMP module has a total of 14 Special Function
Registers for its operation, plus one additional register
to set configuration options. Of these, 8 registers are
used for control and 6 are used for PMP data transfer.
11.1.1 CONTROL REGISTERS
The eight PMP Control registers are:
PMCONH and PMCONL
PMMODEH and PMMODEL
PMSTATL and PMSTATH
PMEH and PMEL
The PMCON registers (Register 11-1 and
Register 11-2) control basic module operations, includ-
ing turning the module on or off. They also configure
address multiplexing and control strobe configuration.
The PMMODE registers (Register 11-3 and
Register 11-4) configure the various Master and Slave
Operating modes, the data width and interrupt
generation.
The PMEH and PMEL registers (Register 11-5 and
Register 11-6) configure the module’s operation at the
hardware (I/O pin) level.
The PMSTAT registers (Register 11-7 and
Register 11-8) provide status flags for the module’s
input and output buffers, depending on the operating
mode.
REGISTER 11-1: PMCONH: PARALLEL PORT CONTROL HIGH BYTE REGISTER
R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PMPEN PSIDL
ADRMUX1 ADRMUX0
PTBEEN PTWREN PTRDEN
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 PMPEN: Parallel Master Port Enable bit
1 = PMP enabled
0 = PMP disabled, no off-chip access performed
bit 6 Unimplemented: Read as0
bit 5 PSIDL: Stop in Idle Mode bit
1 = Discontinue module operation when device enters Idle mode
0 = Continue module operation in Idle mode
bit 4-3 ADRMUX1:ADRMUX0: Address/Data Multiplexing Selection bits
11 = Reserved
10 = All 16 bits of address are multiplexed on PMD<7:0> pins
01 = Lower 8 bits of address are multiplexed on PMD<7:0> pins, upper 8 bits are on PMA<15:8>
00 = Address and data appear on separate pins
bit 2 PTBEEN: Byte Enable Port Enable bit (16-bit Master mode)
1 = PMBE port enabled
0 = PMBE port disabled
bit 1 PTWREN: Write Enable Strobe Port Enable bit
1 = PMWR/PMENB port enabled
0 = PMWR/PMENB port disabled
bit 0 PTRDEN: Read/Write Strobe Port Enable bit
1 = PMRD/PMWR port enabled
0 = PMRD/PMWR port disabled
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 153
PIC18F87J11 FAMILY
REGISTER 11-2: PMCONL: PARALLEL PORT CONTROL LOW BYTE REGISTER
R/W-0 R/W-0 R/W-0(1) R/W-0(1) R/W-0(1) R/W-0 R/W-0 R/W-0
CSF1 CSF0 ALP CS2P CS1P BEP WRSP RDSP
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 CSF1:CSF0: Chip Select Function bits
11 = Reserved
10 = PMCS1 and PMCS2 function as chip select
01 = PMCS2 functions as chip select, PMCS1 used as address bit 14 (PMADDRH address bit 6)
00 = PMCS2 and PMCS1 used as address bits 15 and 14 (PMADDRH address bits 7 and 6)
bit 5 ALP: Address Latch Polarity bit(1)
1 = Active-high (PMALL and PMALH)
0 = Active-low (PMALL and PMALH)
bit 4 CS2P: Chip Select 2 Polarity bit(1)
1 = Active-high (PMCS2)
0 =Active-low (PMCS2
)
bit 3 CS1P: Chip Select 1 Polarity bit(1)
1 = Active-high (PMCS1/PMCS)
0 =Active-low (PMCS1
/PMCS)
bit 2 BEP: Byte Enable Polarity bit
1 = Byte enable active-high (PMBE)
0 = Byte enable active-low (PMBE)
bit 1 WRSP: Write Strobe Polarity bit
For Slave modes and Master mode 2 (PMMODEH<1:0> = 00, 01, 10):
1 = Write strobe active-high (PMWR)
0 = Write strobe active-low (PMWR)
For Master mode 1 (PMMODEH<1:0> = 11):
1 = Enable strobe active-high (PMENB)
0 = Enable strobe active-low (PMENB)
bit 0 RDSP: Read Strobe Polarity bit
For Slave modes and Master mode 2 (PMMODEH<1:0> = 00, 01, 10):
1 = Read strobe active-high (PMRD)
0 = Read strobe active-low (PMRD)
For Master mode 1 (PMMODEH<1:0> = 11):
1 = Read/write strobe active-high (PMRD/PMWR)
0 = Read/write strobe active-low (PMRD/PMWR)
Note 1: These bits have no effect when their corresponding pins are used as address lines.
PIC18F87J11 FAMILY
DS39778C-page 154 Preliminary © 2008 Microchip Technology Inc.
REGISTER 11-3: PMMODEH: PARALLEL PORT MODE HIGH BYTE REGISTER
R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
BUSY IRQM1 IRQM0 INCM1 INCM0 MODE16 MODE1 MODE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 BUSY: Busy bit (Master mode only)
1 = Port is busy
0 = Port is not busy
bit 6-5 IRQM1:IRQM0: Interrupt Request Mode bits
11 = Interrupt generated when Read Buffer 3 is read or Write Buffer 3 is written (Buffered PSP mode)
or on a read or write operation when PMA<1:0> = 11 (Addressable PSP mode only)
10 = No interrupt generated, processor stall activated
01 = Interrupt generated at the end of the read/write cycle
00 = No interrupt generated
bit 4-3 INCM1:INCM0: Increment Mode bits
11 = PSP read and write buffers auto-increment (Legacy PSP mode only)
10 = Decrement ADDR<15,13:0> by 1 every read/write cycle
01 = Increment ADDR<15,13:0> by 1 every read/write cycle
00 = No increment or decrement of address
bit 2 MODE16: 8/16-Bit Mode bit
1 = 16-Bit mode: data register is 16 bits, a read or write to the data register invokes two 8-bit transfers
0 = 8-Bit mode: data register is 8 bits, a read or write to the data register invokes one 8-bit transfer
bit 1-0 MODE1:MODE0: Parallel Port Mode Select bits
11 = Master mode 1 (PMCSx, PMRD/PMWR, PMENB, PMBE, PMA<x:0> and PMD<7:0>)
10 = Master mode 2 (PMCSx, PMRD, PMWR, PMBE, PMA<x:0> and PMD<7:0>)
01 = Enhanced PSP, control signals (PMRD, PMWR, PMCS, PMD<7:0> and PMA<1:0>)
00 = Legacy Parallel Slave Port, control signals (PMRD, PMWR, PMCS and PMD<7:0>)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 155
PIC18F87J11 FAMILY
REGISTER 11-4: PMMODEL: PARALLEL PORT MODE LOW BYTE REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
WAITB1(1) WAITB0(1) WAITM3 WAITM2 WAITM1 WAITM0 WAITE1(1) WAITE0(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 WAITB1:WAITB0: Data Setup to Read/Write Wait State Configuration bits(1)
11 = Data wait of 4 TCY; multiplexed address phase of 4 TCY
10 = Data wait of 3 TCY; multiplexed address phase of 3 TCY
01 = Data wait of 2 TCY; multiplexed address phase of 2 TCY
00 = Data wait of 1 TCY; multiplexed address phase of 1 TCY
bit 5-2 WAITM3:WAITM0: Read to Byte Enable Strobe Wait State Configuration bits
1111 = Wait of additional 15 TCY
...
0001 = Wait of additional 1 T
CY
0000 = No additional wait cycles (operation forced into one TCY)
bit 1-0 WAITE1:WAITE0: Data Hold After Strobe Wait State Configuration bits(1)
11 = Wait of 4 TCY
10 = Wait of 3 TCY
01 = Wait of 2 TCY
00 = Wait of 1 TCY
Note 1: WAITB and WAITE bits are ignored whenever WAITM3:WAITM0 = 0000.
REGISTER 11-5: PMEH: PARALLEL PORT ENABLE HIGH BYTE REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PTEN15 PTEN14 PTEN13 PTEN12 PTEN11 PTEN10 PTEN9 PTEN8
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 PTEN15:PTEN14: PMCSx Strobe Enable bits
1 = PMA15 and PMA14 function as either PMA<15:14> or PMCS2 and PMCS1
0 = PMA15 and PMA14 function as port I/O
bit 5-0 PTEN13:PTEN8: PMP Address Port Enable bits
1 = PMA<13:8> function as PMP address lines
0 = PMA<13:8> function as port I/O
PIC18F87J11 FAMILY
DS39778C-page 156 Preliminary © 2008 Microchip Technology Inc.
REGISTER 11-6: PMEL: PARALLEL PORT ENABLE LOW BYTE REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PTEN7 PTEN6 PTEN5 PTEN4 PTEN3 PTEN2 PTEN1 PTEN0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-2 PTEN7:PTEN2: PMP Address Port Enable bits
1 = PMA<7:2> function as PMP address lines
0 = PMA<7:2> function as port I/O
bit 1-0 PTEN1:PTEN0: PMALH/PMALL Strobe Enable bits
1 = PMA1 and PMA0 function as either PMA<1:0> or PMALH and PMALL
0 = PMA1 and PMA0 pads functions as port I/O
REGISTER 11-7: PMSTATH: PARALLEL PORT STATUS HIGH BYTE REGISTER
R-0 R/W-0 U-0 U-0 R-0 R-0 R-0 R-0
IBF IBOV IB3F IB2F IB1F IB0F
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IBF: Input Buffer Full Status bit
1 = All writable input buffer registers are full
0 = Some or all of the writable input buffer registers are empty
bit 6 IBOV: Input Buffer Overflow Status bit
1 = A write attempt to a full input byte register occurred (must be cleared in software)
0 = No overflow occurred
bit 5-4 Unimplemented: Read as0
bit 3-0 IB3F:IB0F: Input Buffer Status Full bits
1 = Input buffer contains data that has not been read (reading buffer will clear this bit)
0 = Input buffer does not contain any unread data
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 157
PIC18F87J11 FAMILY
REGISTER 11-8: PMSTATL: PARALLEL PORT STATUS LOW BYTE REGISTER
R-1 R/W-0 U-0 U-0 R-1 R-1 R-1 R-1
OBE OBUF OB3E OB2E OB1E OB0E
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 OBE: Output Buffer Empty Status bit
1 = All readable output buffer registers are empty
0 = Some or all of the readable output buffer registers are full
bit 6 OBUF: Output Buffer Underflow Status bit
1 = A read occurred from an empty output byte register (must be cleared in software)
0 = No underflow occurred
bit 5-4 Unimplemented: Read as0
bit 3-0 OBnE: Output Buffer n Status Empty bit
1 = Output buffer is empty (writing data to the buffer will clear this bit)
0 = Output buffer contains data that has not been transmitted
PIC18F87J11 FAMILY
DS39778C-page 158 Preliminary © 2008 Microchip Technology Inc.
11.1.2 DATA REGISTERS
The PMP module uses 6 registers for transferring data
into and out of the microcontroller. They are arranged
as three pairs to allow the option of 16-bit data
operations:
PMDIN1H and PMDIN1L
PMDIN2H and PMDIN2L
PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L
PMDOUT2H and PMDOUT2L
The PMDIN1 register is used for incoming data in Slave
modes, and both input and output data in Master
modes. The PMDIN2 register is used for buffering input
data in select Slave modes.
The PMADDRx/PMDOUT1x registers are actually a
single register pair; the name and function is dictated
by the module’s operating mode. In Master modes, the
registers functions as the PMADDRH and PMADDRL
registers, and contain the address of any incoming or
outgoing data. In Slave modes, the registers function
as PMDOUT1H and PMDOUT1L and are used for
outgoing data.
PMADDRH differs from PMADDRL in that it can also
have limited PMP control functions. When the module
is operating in select Master mode configurations, the
upper two bits of the register can be used to determine
the operation of chip select signals. If chip select
signals are not used, PMADDR simply functions to hold
the upper 8 bits of the address. The function of the
individual bits in PMADDRH is shown in Register 11-9.
The PMDOUT2H and PMDOUT2L registers are only
used in buffered Slave modes and serve as a buffer for
outgoing data.
11.1.3 PAD CONFIGURATION CONTROL
REGISTER
In addition to the module level configuration options,
the PMP module can also be configured at the I/O pin
for electrical operation. This option allows users to
select either the normal Schmitt Trigger input buffer on
digital I/O pins shared with the PMP, or use TTL level
compatible buffers instead. Buffer configuration is
controlled by the PMPTTL bit in the PADCFG1 register.
The PADCFG1 register is one of the shared address
SFRs, and has the same address as the TMR2 regis-
ter. PADCFG1 is accessed by setting the ADSHR bit
(WDTCON<4>). Refer to Section 5.3.4.1 “Shared
Address SFRs” for more information.
REGISTER 11-9: PMADDRH: PARALLEL PORT ADDRESS REGISTER, HIGH BYTE
(MASTER MODES ONLY)(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
CS2 CS1 ADDR<13:8>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0
-n = Value at Reset 1 = bit is set 0 = bit is cleared x = bit is unknown
bit 7 CS2: Chip Select 2 bit
If PMCON<7:6> = 10 or 01:
1 = Chip Select 2 is active
0 = Chip Select 2 is inactive
If PMCON<7:6> = 11 or 00:
Bit functions as ADDR<15>.
bit 6 CS1: Chip Select 1 bit
If PMCON<7:6> = 10:
1 = Chip Select 1 is active
0 = Chip Select 1 is inactive
If PMCON<7:6> = 11 or 0x:
Bit functions as ADDR<14>.
bit 5-0 ADDR13:ADDR0: Destination Address bits
Note 1: In Enhanced Slave mode, PMADDRH functions as PMDOUT1H, one of the Output Data Buffer registers.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 159
PIC18F87J11 FAMILY
11.1.4 PMP MULTIPLEXING OPTIONS
(80-PIN DEVICES)
By default, the PMP and the external memory bus
multiplex some of their signals to the same I/O pins on
PORTD and PORTE. It is possible that some applica-
tions may require the PMP signals to be located
elsewhere. For these instances, the 80-pin devices can
be configured to multiplex the PMP to different I/O
ports. PMP configuration is determined by the PMPMX
Configuration bit setting; by default, the PMP and EMB
modules share PORTD and PORTE. The optional pin
configuration is shown in Table 11-1.
TABLE 11-1: PMP PIN MULTIPLEXING FOR
80-PIN DEVICES
11.2 Slave Port Modes
The primary mode of operation for the module is con-
figured using the MODE1:MODE0 bits in the
PMMODEH register. The setting affects whether the
module acts as a slave or a master and it determines
the usage of the control pins.
11.2.1 LEGACY MODE (PSP)
In Legacy mode (PMMODEH<1:0> = 00 and
PMPEN = 1), the module is configured as a Parallel
Slave Port with the associated enabled module pins
dedicated to the module. In this mode, an external
device, such as another microcontroller or micropro-
cessor, can asynchronously read and write data using
the 8-bit data bus (PMD<7:0>), the read (PMRD), write
(PMWR) and chip select (PMCS1) inputs. It acts as a
slave on the bus and responds to the read/write control
signals.
Figure 11-2 shows the connection of the Parallel Slave
Port. When chip select is active and a write strobe
occurs (PMCS = 1 and PMWR = 1), the data from
PMD<7:0> is captured into the PMDIN1L register.
FIGURE 11-2: LEGACY PARALLEL SLAVE PORT EXAMPLE
PMP Function
Pin Assignment
PMPMX = 1PMPMX = 0
PMD0 PORTD<0> PORTF<7>
PMD1 PORTD<1> PORTF<6>
PMD2 PORTD<2> PORTF<5>
PMD3 PORTD<3> PORTH<4>
PMD4 PORTD<4> PORTA<5>
PMD5 PORTD<5> PORTA<4>
PMD6 PORTD<6> PORTH<3>
PMD7 PORTD<7> PORTH<2>
PMBE PORTE<2> PORTH<5>
PMWR PORTE<1> PORTH<7>
PMRD PORTE<0> PORTH<6>
PMD<7:0>
PMRD
PMWR
Master Address Bus
Data Bus
Control Lines
PMCS
PMD<7:0>
PMRD
PMWR
PIC18 Slave
PMCS1
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DS39778C-page 160 Preliminary © 2008 Microchip Technology Inc.
11.2.1.1 WRITE TO SLAVE PORT
When chip select is active and a write strobe occurs
(PMCS = 1 and PMWR = 1), the data from PMD<7:0>
is captured into the PMDIN1L register. The PMPIF and
IBF flag bits are set when the write ends. The timing for
the control signals in Write mode is shown in
Figure 11-3. The polarity of the control signals are
configurable.
11.2.1.2 READ FROM SLAVE PORT
When chip select is active and a read strobe occurs
(PMCS = 1 and PMRD = 1), the data from the
PMDOUTL1 register (PMDOUTL1<7:0>) is presented
onto PMD<7:0>.The timing for the control signals in
Read mode is shown in Figure 11-4.
FIGURE 11-3: PARALLEL SLAVE PORT WRITE WAVEFORMS
FIGURE 11-4: PARALLEL SLAVE PORT READ WAVEFORMS
PMCS1
| | | | | | | Q4 | Q1 | Q2 | Q3 | Q4
PMWR
PMRD
PMD<7:0>
IBF
OBE
PMPIF
PMCS1
| | | | | | | Q4 | Q1 | Q2 | Q3 | Q4
PMWR
PMRD
PMD<7:0>
IBF
OBE
PMPIF
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 161
PIC18F87J11 FAMILY
11.2.2 BUFFERED PARALLEL SLAVE
PORT MODE
Buffered Parallel Slave Port mode is functionally iden-
tical to the Legacy Parallel Slave Port mode with one
exception: the implementation of 4-level read and write
buffers. Buffered PSP mode is enabled by setting the
INCM bits in the PMMODE register. If the INCM<1:0>
bits are set to ‘11’, the PMP module will act as the
Buffered Parallel Slave Port.
When the Buffered mode is active, the
PMDIN1L,PMDIN1H, PMDIN2L and PMDIN2H regis-
ters become the write buffers and the PMDOUT1L,
PMDOUT1H, PMDOUT2L and PMDOUT2H registers
become the read buffers. Buffers are numbered 0
through 3, starting with the lower byte of PMDIN1L to
PMDIN2H as the read buffers, and PMDOUT1L to
PMDOUT2H as the write buffers.
11.2.2.1 READ FROM SLAVE PORT
For read operations, the bytes will be sent out sequen-
tially, starting with Buffer 0 (PMDOUT1L<7:0>) and
ending with Buffer 3 (PMDOUT2H<7:0>) for every read
strobe. The module maintains an internal pointer to
keep track of which buffer is to be read. Each of the
buffers has a corresponding read status bit, OBxE, in
the PMSTATL register. This bit is cleared when a buffer
contains data that has not been written to the bus, and
is set when data is written to the bus. If the current
buffer location being read from is empty, a buffer under-
flow is generated, and the Buffer Overflow flag bit
OBUF is set. If all 4 OBxE status bits are set, then the
Output Buffer Empty flag (OBE) will also be set.
11.2.2.2 WRITE TO SLAVE PORT
For write operations, the data is be stored sequentially,
starting with Buffer 0 (PMDIN1L<7:0>) and ending with
Buffer 3 (PMDIN2H<7:0). As with read operations, the
module maintains an internal pointer to the buffer that
is to be written next.
The input buffers have their own write status bits, IBxF
in the PMSTATH register. The bit is set when the buffer
contains unread incoming data, and cleared when the
data has been read. The flag bit is set on the write
strobe. If a write occurs on a buffer when its associated
IBxF bit is set, the Buffer Overflow flag, IBOV, is set;
any incoming data in the buffer will be lost. If all 4 IBxF
flags are set, the Input Buffer Full Flag (IBF) is set.
In Buffered Slave mode, the module can be configured
to generate an interrupt on every read or write strobe
(IRQM1:IRQM0 = 01). It can be configured to generate
an interrupt on a read from Read Buffer 3 or a write to
Write Buffer 3, which is essentially an interrupt every
fourth read or write strobe (RQM1:IRQM0 = 11). When
interrupting every fourth byte for input data, all input
buffer registers should be read to clear the IBxF flags.
If these flags are not cleared, then their is a risk of
hitting an overflow condition.
FIGURE 11-5: PARALLEL MASTER/SLAVE CONNECTION BUFFERED EXAMPLE
PMD<7:0>
PMRD
PMWR
PMCS
Data Bus
Control Lines
PMRD
PMWR
PIC18 Slave
PMCS1
PMDOUT1L (0)
PMDOUT1H (1)
PMDOUT2L (2)
PMDOUT2H (3)
PMDIN1L (0)
PMDIN1H (1)
PMDIN2L (2)
PMDIN2H (3)
PMD<7:0> Write
Address
Pointer
Read
Address
Pointer
Master
PIC18F87J11 FAMILY
DS39778C-page 162 Preliminary © 2008 Microchip Technology Inc.
11.2.3 ADDRESSABLE PARALLEL SLAVE
PORT MODE
In the Addressable Parallel Slave Port mode
(PMMODEH<1:0> = 01), the module is configured with
two extra inputs, PMA<1:0>, which are the address
lines 1 and 0. This makes the 4-byte buffer space
directly addressable as fixed pairs of read and write
buffers. As with Buffered Legacy mode, data is output
from PMDOUT1L, PMDOUT1H, PMDOUT2L and
PMDOUT2H, and is read in PMDIN1L, PMDIN1H,
PMDIN2L and PMDIN2H. Table 11-2 shows the buffer
addressing for the incoming address to the input and
output registers.
TABLE 11-2: SLAVE MODE BUFFER
ADDRESSING
FIGURE 11-6: PARALLEL MASTER/SLAVE CONNECTION ADDRESSED BUFFER EXAMPLE
PMADDR
<1:0>
Output Register
(Buffer)
Input Register
(Buffer)
00 PMDOUT1L (0) PMDIN1L (0)
01 PMDOUT1H (1) PMDIN1H (1)
10 PMDOUT2L (2) PMDIN2L (2)
11 PMDOUT2H (3) PMDIN2H (3)
PMD<7:0>
PMRD
PMWR
Master
PMCS
PMA<1:0>
Address Bus
Data Bus
Control Lines
PMRD
PMWR
PIC18F Slave
PMCS1
PMDOUT1L (0)
PMDOUT1H (1)
PMDOUT2L (2)
PMDOUT2H (3)
PMDIN1L (0)
PMDIN1H (1)
PMDIN2L (2)
PMDIN2H (3)
PMD<7:0> Write
Address
Decode
Read
Address
Decode
PMA<1:0>
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 163
PIC18F87J11 FAMILY
11.2.3.1 READ FROM SLAVE PORT
When chip select is active and a read strobe occurs
(PMCS = 1 and PMRD = 1), the data from one of the
four output bytes is presented onto PMD<7:0>. Which
byte is read depends on the 2-bit address placed on
ADDR<1:0>. Table 11-2 shows the corresponding
output registers and their associated address.
When an output buffer is read, the corresponding
OBxE bit is set. The OBE flag bit is set when all the
buffers are empty. If any buffer is already empty
(OBxE = 1), the next read to that buffer will generate an
OBUF event.
FIGURE 11-7: PARALLEL SLAVE PORT READ WAVEFORMS
11.2.3.2 WRITE TO SLAVE PORT
When chip select is active and a write strobe occurs
(PMCS = 1 and PMWR = 1), the data from PMD<7:0>
is captured into one of the four input buffer bytes.
Which byte is written depends on the 2-bit address
placed on ADDRL<1:0>. Table 11-2 shows the corre-
sponding input registers and their associated address.
When an input buffer is written, the corresponding IBxF
bit is set. The IBF flag bit is set when all the buffers are
written. If any buffer is already written (IBxF = 1), the
next write strobe to that buffer will generate an OBUF
event and the byte will be discarded.
FIGURE 11-8: PARALLEL SLAVE PORT WRITE WAVEFORMS
PMCS
Q1 | Q2 | Q3 | Q4 | Q1 | Q2 | Q3 | Q4 | Q1 | Q2 | Q3 | Q4
PMWR
PMRD
PMD<7:0>
PMA<1:0>
OBE
PMPIF
PMCS
Q1 | Q2 | Q3 | Q4 | Q1 | Q2 | Q3 | Q4 | Q1 | Q2 | Q3 | Q4
PMWR
PMRD
PMD<7:0>
IBF
PMPIF
PMA<1:0>
PIC18F87J11 FAMILY
DS39778C-page 164 Preliminary © 2008 Microchip Technology Inc.
11.3 Master Port Modes
In its Master modes, the PMP module provides an 8-bit
data bus, up to 16 bits of address, and all the necessary
control signals to operate a variety of external parallel
devices, such as memory devices, peripherals and
slave microcontrollers. To use the PMP as a master,
the module must be enabled (PMPEN = 1) and the
mode must be set to one of the two possible Master
modes (PMMODEH<1:0> = 10 or 11).
Because there are a number of parallel devices with a
variety of control methods, the PMP module is
designed to be extremely flexible to accommodate a
range of configurations. Some of these features
include:
8 and 16-Bit Data modes on an 8-bit data bus
Configurable address/data multiplexing
Up to two chip select lines
Up to 16 selectable address lines
Address auto-increment and auto-decrement
Selectable polarity on all control lines
Configurable wait states at different stages of the
read/write cycle
11.3.1 PMP AND I/O PIN CONTROL
Multiple control bits are used to configure the presence
or absence of control and address signals in the mod-
ule. These bits are PTBEEN, PTWREN, PTRDEN, and
PTEN<15:0>. They give the user the ability to conserve
pins for other functions and allow flexibility to control
the external address. When any one of these bits is set,
the associated function is present on its associated pin;
when clear, the associated pin reverts to its defined I/O
port function.
Setting a PTEN bit will enable the associated pin as an
address pin and drive the corresponding data con-
tained in the PMADDR register. Clearing the PTENx bit
will force the pin to revert to its original I/O function.
For the pins configured as chip select (PMCS1 or
PMCS2) with the corresponding PTENx bit set, chip
select pins drive inactive data (with polarity defined by
the CS1P and CS2P bits) when a read or write opera-
tion is not being performed. The PTEN0 and PTEN1
bits also control the PMALL and PMALH signals. When
multiplexing is used, the associated address latch
signals should be enabled.
11.3.2 READ/WRITE CONTROL
The PMP module supports two distinct read/write
_signaling methods. In Master mode 1, read and write
strobes are combined into a single control line,
PMRD/PMWR. A second control line, PMENB, deter-
mines when a read or write action is to be taken. In
Master mode 2, separate read and write strobes
(PMRD and PMWR) are supplied on separate pins.
All control signals (PMRD, PMWR, PMBE, PMENB,
PMAL and PMCSx) can be individually configured as
either positive or negative polarity. Configuration is
controlled by separate bits in the PMCONL register.
Note that the polarity of control signals that share the
same output pin (for example, PMWR and PMENB) are
controlled by the same bit; the configuration depends
on which Master Port mode is being used.
11.3.3 DATA WIDTH
The PMP supports data widths of both 8 and 16 bits.
The data width is selected by the MODE16 bit
(PMMODEH<2>). Because the data path into and out
of the module is only 8 bits wide, 16-bit operations are
always handled in a multiplexed fashion, with the Least
Significant Byte of data being presented first. To differ-
entiate data bytes, the Byte Enable (PMBE) control
strobe is used to signal when the Most Significant Byte
of data is being presented on the data lines.
11.3.4 ADDRESS MULTIPLEXING
In either of the Master modes (PMMODEH<1:0> = 1x),
the user can configure the address bus to be multiplexed
together with the data bus. This is accomplished using
the ADRMUX1:ADRMUX0 bits (PMCONH<4:3>). There
are three address multiplexing modes available; typical
pinout configurations for these modes are shown in
Figure 11-9, Figure 11-10 and Figure 11-11.
In Demultiplexed mode (PMCONH<4:3> = 00), data
and address information are completely separated.
Data bits are presented on PMD<7:0>, and address
bits are presented on PMADDRH<7:0> and
PMADDRL<7:0>.
In Partially Multiplexed mode (PMCONH<4:3> = 01),
the lower eight bits of the address are multiplexed with
the data pins on PMD<7:0>. The upper eight bits of
address are unaffected and are presented on
PMADDRH<7:0>. The PMA0 pin is used as an address
latch and presents the Address Latch Low (PMALL)
enable strobe. The read and write sequences are
extended by a complete CPU cycle during which the
address is presented on the PMD<7:0> pins.
In Fully Multiplexed mode (PMCONH<4:3> = 10), the
entire 16 bits of the address are multiplexed with the
data pins on PMD<7:0>. The PMA0 and PMA1 pins are
used to present Address Latch Low (PMALL) enable
and Address Latch High (PMALH) enable strobes,
respectively. The read and write sequences are
extended by two complete CPU cycles. During the first
cycle, the lower eight bits of the address are presented
on the PMD<7:0> pins with the PMALL strobe active.
During the second cycle, the upper eight bits of the
address are presented on the PMD<7:0> pins with the
PMALH strobe active. In the event the upper address
bits are configured as chip select pins, the
corresponding address bits are automatically forced
to 0’.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 165
PIC18F87J11 FAMILY
FIGURE 11-9: DEMULTIPLEXED ADDRESSING MODE (SEPARATE READ AND WRITE
STROBES, TWO CHIP SELECTS)
FIGURE 11-10: PARTIALLY MULTIPLEXED ADDRESSING MODE (SEPARATE READ AND
WRITE STROBES, TWO CHIP SELECTS)
FIGURE 11-11: FULLY MULTIPLEXED ADDRESSING MODE (SEPARATE READ AND WRITE
STROBES, TWO CHIP SELECTS)
PMRD
PMWR
PMD<7:0>
PMCS1
PMA<13:0>
PMCS2
PIC18F
Address Bus
Data Bus
Control Lines
PMRD
PMWR
PMD<7:0>
PMCS1
PMA<13:8>
PMALL
PMA<7:0>
PMCS2
PIC18F
Address Bus
Multiplexed
Data and
Address Bus
Control Lines
PMRD
PMWR
PMD<7:0>
PMCS1
PMALH
PMA<13:8>
PMCS2
PIC18F
Multiplexed
Data and
Address Bus
Control Lines
PMALL
PIC18F87J11 FAMILY
DS39778C-page 166 Preliminary © 2008 Microchip Technology Inc.
11.3.5 CHIP SELECT FEATURES
Up to two chip select lines, PMCS1 and PMCS2, are
available for the Master modes of the PMP. The two
chip select lines are multiplexed with the Most Signifi-
cant bits of the address bus (PMADDRH<6> and
PMADDRH<7>). When a pin is configured as a chip
select, it is not included in any address
auto-increment/decrement. The function of the chip
select signals is configured using the chip select
function bits (PMCONL <7:6>).
11.3.6 AUTO-INCREMENT/DECREMENT
While the module is operating in one of the Master
modes, the INCM bits (PMMODEH<3:4>) control the
behavior of the address value. The address can be
made to automatically increment or decrement after
each read and write operation. The address increments
once each operation is completed and the BUSY bit
goes to ‘0. If the chip select signals are disabled and
configured as address bits, the bits will participate in
the increment and decrement operations; otherwise,
the CS2 and CS1 bit values will be unaffected.
11.3.7 WAIT STATES
In Master mode, the user has control over the duration
of the read, write and address cycles by configuring the
module wait states. Three portions of the cycle, the
beginning, middle, and end, are configured using the
corresponding WAITBx, WAITMx and WAITEx bits in
the PMMODEL register.
The WAITB1:WAITB0 bits (PMMODEL<7:6>) set the
number of wait cycles for the data setup prior to the
PMRD/PMWT strobe in Mode 10, or prior to the
PMENB strobe in Mode 11. The WAITM3:WAITM0 bits
(PMMODEL<5:2>) set the number of wait cycles for the
PMRD/PMWT strobe in Mode 10, or for the PMENB
strobe in Mode 11. When this wait state setting is 0,
then WAITB and WAITE have no effect. The
WAITE1:WAITE0 bits (PMMODEL<1:0>) define the
number of wait cycles for the data hold time after the
PMRD/PMWT strobe in Mode 10, or after the PMENB
strobe in Mode 11.
11.3.8 READ OPERATION
To perform a read on the Parallel Master Port, the user
reads the PMDIN1L register. This causes the PMP to
output the desired values on the chip select lines and
the address bus. Then the read line (PMRD) is strobed.
The read data is placed into the PMDIN1L register.
If the 16-bit mode is enabled (MODE16 = 1), the read
of the low byte of the PMDIN1L register will initiate two
bus reads. The first read data byte is placed into the
PMDIN1L register, and the second read data is placed
into the PMDIN1H.
Note that the read data obtained from the PMDIN1L
register is actually the read value from the previous
read operation. Hence, the first user read will be a
dummy read to initiate the first bus read and fill the read
register. Also, the requested read value will not be
ready until after the BUSY bit is observed low. Thus, in
a back-to-back read operation, the data read from the
register will be the same for both reads. The next read
of the register will yield the new value.
11.3.9 WRITE OPERATION
To perform a write onto the parallel bus, the user writes
to the PMDIN1L register. This causes the module to
first output the desired values on the chip select lines
and the address bus. The write data from the PMDIN1L
register is placed onto the PMD<7:0> data bus. Then
the write line (PMWR) is strobed. If the 16-bit mode is
enabled (MODE16 = 1), the write to the PMDIN1L reg-
ister will initiate two bus writes. First write will consist of
the data contained in PMDIN1L and the second write
will contain the PMDIN1H.
11.3.10 PARALLEL MASTER PORT STATUS
11.3.10.1 The BUSY Bit
In addition to the PMP interrupt, a BUSY bit is provided
to indicate the status of the module. This bit is only
used in Master mode. While any read or write operation
is in progress, the BUSY bit is set for all but the very last
CPU cycle of the operation. In effect, if a single-cycle
read or write operation is requested, the BUSY bit will
never be active. This allows back-to-back transfers.
While the bit is set, any request by the user to initiate a
new operation will be ignored (i.e., writing or reading
the lower byte of the PMDIN1L register will not initiate
either a read nor a write).
11.3.10.2 INTERRUPTS
When the PMP module interrupt is enabled for Master
mode, the module will interrupt on every completed
read or write cycle; otherwise, the BUSY bit is available
to query the status of the module.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 167
PIC18F87J11 FAMILY
11.3.11 MASTER MODE TIMING
This section contains a number of timing examples that
represent the common Master mode configuration
options. These options vary from 8-bit to 16-bit data,
fully demultiplexed to fully multiplexed address, as well
as wait states.
FIGURE 11-12: READ AND WRITE TIMING, 8-BIT DATA, DEMULTIPLEXED ADDRESS
FIGURE 11-13: READ TIMING, 8-BIT DATA, PARTIALLY MULTIPLEXED ADDRESS
PMCS2
PMWR
PMRD
PMPIF
PMD<7:0>
PMCS1
PMA<13:0>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
BUSY
Q2 Q3 Q4Q1
PMCS2
PMWR
PMRD
PMALL
PMD<7:0>
PMCS1
PMA<13:8>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
BUSY
Data
Address<7:0>
PIC18F87J11 FAMILY
DS39778C-page 168 Preliminary © 2008 Microchip Technology Inc.
FIGURE 11-14: READ TIMING, 8-BIT DATA, WAIT STATES ENABLED,
PARTIALLY MULTIPLEXED ADDRESS
FIGURE 11-15: WRITE TIMING, 8-BIT DATA, PARTIALLY MULTIPLEXED ADDRESS
FIGURE 11-16: WRITE TIMING, 8-BIT DATA, WAIT STATES ENABLED,
PARTIALLY MULTIPLEXED ADDRESS
PMCS2
PMRD
PMWR
PMALL
PMD<7:0>
PMCS1
PMA<13:8>
Q1- - -
PMPIF
Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - -
WAITM<3:0> = 0010
WAITE<1:0> = 00
WAITB<1:0> = 01
BUSY
Address<7:0> Data
PMCS2
PMWR
PMRD
PMALL
PMD<7:0>
PMCS1
PMA<13:8>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
Data
BUSY
Address<7:0>
PMCS2
PMWR
PMRD
PMALL
PMD<7:0>
PMCS1
PMA<13:8>
Q1- - -
PMPIF
Data
Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - -
WAITM<3:0> = 0010
WAITE<1:0> = 00
WAITB<1:0> = 01
BUSY
Address<7:0>
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 169
PIC18F87J11 FAMILY
FIGURE 11-17: READ TIMING, 8-BIT DATA, PARTIALLY MULTIPLEXED ADDRESS,
ENABLE STROBE
FIGURE 11-18: WRITE TIMING, 8-BIT DATA, PARTIALLY MULTIPLEXED ADDRESS,
ENABLE STROBE
FIGURE 11-19: READ TIMING, 8-BIT DATA, FULLY MULTIPLEXED 16-BIT ADDRESS
PMCS2
PMRD/PMWR
PMENB
PMALL
PMD<7:0>
PMCS1
PMA<13:8>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
BUSY
Address<7:0> Data
PMCS2
PMRD/PMWR
PMENB
PMALL
PMD<7:0>
PMCS1
PMA<13:8>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
Data
BUSY
Address<7:0>
PMCS2
PMWR
PMRD
PMALL
PMD<7:0>
PMCS1
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMALH
Data
PMPIF
BUSY
Address<7:0> Address<15:8>
PIC18F87J11 FAMILY
DS39778C-page 170 Preliminary © 2008 Microchip Technology Inc.
FIGURE 11-20: WRITE TIMING, 8-BIT DATA, FULLY MULTIPLEXED 16-BIT ADDRESS
FIGURE 11-21: READ TIMING, 16-BIT DATA, DEMULTIPLEXED ADDRESS
FIGURE 11-22: WRITE TIMING, 16-BIT DATA, DEMULTIPLEXED ADDRESS
PMCS2
PMWR
PMRD
PMALL
PMD<7:0>
PMCS1
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMALH
Data
PMPIF
BUSY
Address<7:0> Address<15:8>
PMCS2
PMWR
PMRD
PMD<7:0>
PMCS1
PMA<13:0>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
MSBLSB
PMBE
BUSY
PMCS2
PMWR
PMRD
PMD<7:0>
PMCS1
PMA<13:0>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
LSB MSB
PMBE
BUSY
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 171
PIC18F87J11 FAMILY
FIGURE 11-23: READ TIMING, 16-BIT MULTIPLEXED DATA,
PARTIALLY MULTIPLEXED ADDRESS
FIGURE 11-24: WRITE TIMING, 16-BIT MULTIPLEXED DATA,
PARTIALLY MULTIPLEXED ADDRESS
PMCS2
PMWR
PMRD
PMALL
PMD<7:0>
PMCS1
PMA<13:8>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
LSB MSB
PMBE
BUSY
Address<7:0>
PMCS2
PMWR
PMRD
PMALL
PMD<7:0>
PMCS1
PMA<13:8>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
LSB MSB
PMBE
BUSY
Address<7:0>
PIC18F87J11 FAMILY
DS39778C-page 172 Preliminary © 2008 Microchip Technology Inc.
FIGURE 11-25: READ TIMING, 16-BIT MULTIPLEXED DATA,
FULLY MULTIPLEXED 16-BIT ADDRESS
FIGURE 11-26: WRITE TIMING, 16-BIT MULTIPLEXED DATA,
FULLY MULTIPLEXED 16-BIT ADDRESS
PMCS2
PMWR
PMRD
PMBE
PMD<7:0>
PMCS1
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMALH
LSB
PMPIF
PMALL
BUSY
Q2 Q3 Q4Q1
Address<7:0> Address<15:8> MSB
PMCS2
PMWR
PMRD
PMBE
PMD<7:0>
PMCS1
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMALH
PMALL
MSB
LSB
PMPIF
BUSY
Q2 Q3 Q4Q1
Address<7:0> Address<15:8>
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 173
PIC18F87J11 FAMILY
11.4 Application Examples
This section introduces some potential applications for
the PMP module.
11.4.1 MULTIPLEXED MEMORY OR
PERIPHERAL
Figure 11-27 demonstrates the hookup of a memory or
other addressable peripheral in Full Multiplex mode.
Consequently, this mode achieves the best pin saving
from the microcontroller perspective. However, for this
configuration, there needs to be some external latches
to maintain the address.
FIGURE 11-27: EXAMPLE OF A MULTIPLEXED ADDRESSING APPLICATION
11.4.2 PARTIALLY MULTIPLEXED
MEMORY OR PERIPHERAL
Partial multiplexing implies using more pins; however,
for a few extra pins, some extra performance can be
achieved. Figure 11-28 shows an example of a mem-
ory or peripheral that is partially multiplexed with an
external latch. If the peripheral has internal latches as
shown in Figure 11-29, then no extra circuitry is
required except for the peripheral itself.
FIGURE 11-28: EXAMPLE OF A PARTIALLY MULTIPLEXED ADDRESSING APPLICATION
FIGURE 11-29: EXAMPLE OF AN 8-BIT MULTIPLEXED ADDRESS AND DATA APPLICATION
PMD<7:0>
PMALH
D<7:0>
373 A<15:0>
D<7:0>
A<7:0>
373
PMRD
PMWR
OE WR
CE
PIC18F
Address Bus
Data Bus
Control Lines
PMCS
PMALL
A<15:8>
PMA<14:7>
D<7:0>
373 A<14:0>
D<7:0>
A<7:0>
PMRD
PMWR
OE WR
CE
PIC18F
Address Bus
Data Bus
Control Lines
PMCS
PMALL
A<14:8>
PMD<7:0>
ALE
PMRD
PMWR
RD
WR
CS
PIC18F
Address Bus
Data Bus
Control Lines
PMCS
PMALL
AD<7:0>
Parallel Peripheral
PMD<7:0>
PIC18F87J11 FAMILY
DS39778C-page 174 Preliminary © 2008 Microchip Technology Inc.
11.4.3 PARALLEL EEPROM EXAMPLE
Figure 11-30 shows an example connecting parallel
EEPROM to the PMP. Figure 11-31 shows a slight
variation to this, configuring the connection for 16-bit
data from a single EEPROM.
FIGURE 11-30: PARALLEL EEPROM EXAMPLE (UP TO 15-BIT ADDRESS, 8-BIT DATA)
FIGURE 11-31: PARALLEL EEPROM EXAMPLE (UP TO 15-BIT ADDRESS, 16-BIT DATA)
11.4.4 LCD CONTROLLER EXAMPLE
The PMP module can be configured to connect to a
typical LCD controller interface, as shown in
Figure 11-32. In this case, the PMP module is config-
ured for active-high control signals since common LCD
displays require active-high control.
FIGURE 11-32: LCD CONTROL EXAMPLE (BYTE MODE OPERATION)
PMA<n:0> A<n:0>
D<7:0>
PMRD
PMWR
OE
WR
CE
PIC18F
Address Bus
Data Bus
Control Lines
PMCS
PMD<7:0>
Parallel EEPROM
PMA<n:0> A<n:1>
D<7:0>
PMRD
PMWR
OE
WR
CE
PIC18F
Address Bus
Data Bus
Control Lines
PMCS
PMD<7:0>
Parallel EEPROM
PMBE A0
PMRD/PMWR
D<7:0>
PIC18F
Address Bus
Data Bus
Control Lines
PMA0
R/W
RS
E
LCD Controller
PMCS
PM<7:0>
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 175
PIC18F87J11 FAMILY
TABLE 11-3: REGISTERS ASSOCIATED WITH PMP MODULE
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PMCONH PMPEN PSIDL ADRMUX1 ADRMUX0 PTBEEN PTWREN PTRDEN 60
PMCONL CSF1 CSF0 ALP CS2P CS1P BEP WRSP RDSP 60
PMADDRH/ CS2 CS1 Parallel Master Port Address High Byte 60
PMDOUT1H(1) Parallel Port Out Data High Byte (Buffer 1) 60
PMADDRL/ Parallel Master Port Address Low Byte 60
PMDOUT1L(1) Parallel Port Out Data Low Byte (Buffer 0) 60
PMDOUT2H Parallel Port Out Data High Byte (Buffer 3) 60
PMDOUT2L Parallel Port Out Data Low Byte (Buffer 2) 60
PMDIN1H Parallel Port In Data High Byte (Buffer 1) 60
PMDIN1L Parallel Port In Data Low Byte (Buffer 0) 60
PMDIN2H Parallel Port In Data High Byte (Buffer 3) 60
PMDIN2L Parallel Port In Data Low Byte (Buffer 2) 60
PMMODEH BUSY IRQM1 IRQM0 INCM1 INCM0 MODE16 MODE1 MODE0 60
PMMODEL WAITB1 WAITB0 WAITM3 WAITM2 WAITM1 WAITM0 WAITE1 WAITE0 60
PMEH PTEN15 PTEN14 PTEN13 PTEN12 PTEN11 PTEN10 PTEN9 PTEN8 60
PMEL PTEN7 PTEN6 PTEN5 PTEN4 PTEN3 PTEN2 PTEN1 PTEN0 60
PMSTATH IBF IBOV IB3F IB2F IB1F IB0F 60
PMSTATL OBE OBUF OB3E OB2E OB1E OB0E 60
PADCFG1(2) —PMPTTL56
Legend: = unimplemented, read as0. Shaded cells are not used during PMP operation.
Note 1: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the physical registers and
addresses, but have different functions determined by the module’s operating mode.
2: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
PIC18F87J11 FAMILY
DS39778C-page 176 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 177
PIC18F87J11 FAMILY
12.0 TIMER0 MODULE
The Timer0 module incorporates the following features:
Software selectable operation as a timer or
counter in both 8-bit or 16-bit modes
Readable and writable registers
Dedicated 8-bit, software programmable
prescaler
Selectable clock source (internal or external)
Edge select for external clock
Interrupt-on-overflow
The T0CON register (Register 12-1) controls all
aspects of the module’s operation, including the
prescale selection. It is both readable and writable.
A simplified block diagram of the Timer0 module in 8-bit
mode is shown in Figure 12-1. Figure 12-2 shows a
simplified block diagram of the Timer0 module in 16-bit
mode.
REGISTER 12-1: T0CON: TIMER0 CONTROL REGISTER
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 TMR0ON: Timer0 On/Off Control bit
1 = Enables Timer0
0 = Stops Timer0
bit 6 T08BIT: Timer0 8-Bit/16-Bit Control bit
1 = Timer0 is configured as an 8-bit timer/counter
0 = Timer0 is configured as a 16-bit timer/counter
bit 5 T0CS: Timer0 Clock Source Select bit
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock (CLKO)
bit 4 T0SE: Timer0 Source Edge Select bit
1 = Increment on high-to-low transition on T0CKI pin
0 = Increment on low-to-high transition on T0CKI pin
bit 3 PSA: Timer0 Prescaler Assignment bit
1 = TImer0 prescaler is not assigned. Timer0 clock input bypasses prescaler.
0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output.
bit 2-0 T0PS2:T0PS0: Timer0 Prescaler Select bits
111 = 1:256 Prescale value
110 = 1:128 Prescale value
101 = 1:64 Prescale value
100 = 1:32 Prescale value
011 = 1:16 Prescale value
010 = 1:8 Prescale value
001 = 1:4 Prescale value
000 = 1:2 Prescale value
PIC18F87J11 FAMILY
DS39778C-page 178 Preliminary © 2008 Microchip Technology Inc.
12.1 Timer0 Operation
Timer0 can operate as either a timer or a counter. The
mode is selected with the T0CS bit (T0CON<5>). In
Timer mode (T0CS = 0), the module increments on
every clock by default unless a different prescaler value
is selected (see Section 12.3 “Prescaler”). If the
TMR0 register is written to, the increment is inhibited
for the following two instruction cycles. The user can
work around this by writing an adjusted value to the
TMR0 register.
The Counter mode is selected by setting the T0CS bit
(= 1). In this mode, Timer0 increments either on every
rising or falling edge of pin RA4/T0CKI. The increment-
ing edge is determined by the Timer0 Source Edge
Select bit, T0SE (T0CON<4>); clearing this bit selects
the rising edge. Restrictions on the external clock input
are discussed below.
An external clock source can be used to drive Timer0;
however, it must meet certain requirements to ensure
that the external clock can be synchronized with the
internal phase clock (T
OSC). There is a delay between
synchronization and the onset of incrementing the
timer/counter.
12.2 Timer0 Reads and Writes in
16-Bit Mode
TMR0H is not the actual high byte of Timer0 in 16-bit
mode. It is actually a buffered version of the real high
byte of Timer0 which is not directly readable nor writ-
able (refer to Figure 12-2). TMR0H is updated with the
contents of the high byte of Timer0 during a read of
TMR0L. This provides the ability to read all 16 bits of
Timer0 without having to verify that the read of the high
and low byte were valid, due to a rollover between
successive reads of the high and low byte.
Similarly, a write to the high byte of Timer0 must also
take place through the TMR0H Buffer register. The high
byte is updated with the contents of TMR0H when a
write occurs to TMR0L. This allows all 16 bits of Timer0
to be updated at once.
FIGURE 12-1: TIMER0 BLOCK DIAGRAM (8-BIT MODE)
FIGURE 12-2: TIMER0 BLOCK DIAGRAM (16-BIT MODE)
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.
T0CKI pin
T0SE
0
1
1
0
T0CS
FOSC/4
Programmable
Prescaler
Sync with
Internal
Clocks
TMR0L
(2 TCY Delay)
Internal Data Bus
PSA
T0PS2:T0PS0
Set
TMR0IF
on Overflow
38
8
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.
T0CKI pin
T0SE
0
1
1
0
T0CS
FOSC/4
Sync with
Internal
Clocks
TMR0L
(2 TCY Delay)
Internal Data Bus
8
PSA
T0PS2:T0PS0
Set
TMR0IF
on Overflow
3
TMR0
TMR0H
High Byte
88
8
Read TMR0L
Write TMR0L
8
Programmable
Prescaler
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 179
PIC18F87J11 FAMILY
12.3 Prescaler
An 8-bit counter is available as a prescaler for the Timer0
module. The prescaler is not directly readable or writable.
Its value is set by the PSA and T0PS2:T0PS0 bits
(T0CON<3:0>) which determine the prescaler
assignment and prescale ratio.
Clearing the PSA bit assigns the prescaler to the
Timer0 module. When it is assigned, prescale values
from 1:2 through 1:256 in power-of-2 increments are
selectable.
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (e.g., CLRF TMR0, MOVWF
TMR0, BSF TMR0, etc.) clear the prescaler count.
12.3.1 SWITCHING PRESCALER
ASSIGNMENT
The prescaler assignment is fully under software
control and can be changed “on-the-fly” during program
execution.
12.4 Timer0 Interrupt
The TMR0 interrupt is generated when the TMR0
register overflows from FFh to 00h in 8-bit mode, or
from FFFFh to 0000h in 16-bit mode. This overflow sets
the TMR0IF flag bit. The interrupt can be masked by
clearing the TMR0IE bit (INTCON<5>). Before
re-enabling the interrupt, the TMR0IF bit must be
cleared in software by the Interrupt Service Routine.
Since Timer0 is shut down in Sleep mode, the TMR0
interrupt cannot awaken the processor from Sleep.
TABLE 12-1: REGISTERS ASSOCIATED WITH TIMER0
Note: Writing to TMR0 when the prescaler is
assigned to Timer0 will clear the prescaler
count but will not change the prescaler
assignment.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
TMR0L Timer0 Register Low Byte 56
TMR0H Timer0 Register High Byte 56
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 56
TRISA TRISA7(1) TRISA6(1) TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 58
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by Timer0.
Note 1:
These bits are only available in select oscillator modes (FOSC2 Configuration bit =
0
); otherwise, they are
unimplemented.
PIC18F87J11 FAMILY
DS39778C-page 180 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 181
PIC18F87J11 FAMILY
13.0 TIMER1 MODULE
The Timer1 timer/counter module incorporates these
features:
Software selectable operation as a 16-bit timer or
counter
Readable and writable 8-bit registers (TMR1H
and TMR1L)
Selectable clock source (internal or external) with
device clock or Timer1 oscillator internal options
Interrupt on overflow
Reset on ECCPx Special Event Trigger
Device clock status flag (T1RUN)
A simplified block diagram of the Timer1 module is
shown in Figure 13-1. A block diagram of the module’s
operation in Read/Write mode is shown in Figure 13-2.
The module incorporates its own low-power oscillator
to provide an additional clocking option. The Timer1
oscillator can also be used as a low-power clock source
for the microcontroller in power-managed operation.
Timer1 can also be used to provide Real-Time Clock
(RTC) functionality to applications with only a minimal
addition of external components and code overhead.
Timer1 is controlled through the T1CON Control
register (Register 13-1). It also contains the Timer1
Oscillator Enable bit (T1OSCEN). Timer1 can be
enabled or disabled by setting or clearing control bit,
TMR1ON (T1CON<0>).
REGISTER 13-1: T1CON: TIMER1 CONTROL REGISTER(1)
R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RD16 T1RUN T1CKPS1 T1CKPS0
T1OSCEN
T1SYNC TMR1CS TMR1ON
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 RD16: 16-Bit Read/Write Mode Enable bit
1 = Enables register read/write of TImer1 in one 16-bit operation
0 = Enables register read/write of Timer1 in two 8-bit operations
bit 6 T1RUN: Timer1 System Clock Status bit
1 = Device clock is derived from Timer1 oscillator
0 = Device clock is derived from another source
bit 5-4 T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits
11 = 1:8 Prescale value
10 = 1:4 Prescale value
01 = 1:2 Prescale value
00 = 1:1 Prescale value
bit 3 T1OSCEN: Timer1 Oscillator Enable bit
1 = Timer1 oscillator is enabled
0 = Timer1 oscillator is shut off
The oscillator inverter and feedback resistor are turned off to eliminate power drain.
bit 2 T1SYNC: Timer1 External Clock Input Synchronization Select bit
When TMR1CS = 1:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
When TMR1CS = 0:
This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.
bit 1 TMR1CS: Timer1 Clock Source Select bit
1 = External clock from pin RC0/T1OSO/T13CKI (on the rising edge)
0 = Internal clock (FOSC/4)
bit 0 TMR1ON: Timer1 On bit
1 = Enables Timer1
0 =Stops Timer1
Note 1: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
PIC18F87J11 FAMILY
DS39778C-page 182 Preliminary © 2008 Microchip Technology Inc.
13.1 Timer1 Operation
Timer1 can operate in one of these modes:
•Timer
Synchronous Counter
Asynchronous Counter
The operating mode is determined by the clock select
bit, TMR1CS (T1CON<1>). When TMR1CS is cleared
(= 0), Timer1 increments on every internal instruction
cycle (FOSC/4). When the bit is set, Timer1 increments
on every rising edge of the Timer1 external clock input
or the Timer1 oscillator, if enabled.
When Timer1 is enabled, the RC1/T1OSI and
RC0/T1OSO/T13CKI pins become inputs. This means
the values of TRISC<1:0> are ignored and the pins are
read as 0’.
FIGURE 13-1: TIMER1 BLOCK DIAGRAM
FIGURE 13-2: TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
T1SYNC
TMR1CS
T1CKPS1:T1CKPS0
Sleep Input
T1OSCEN(1)
FOSC/4
Internal
Clock
On/Off
Prescaler
1, 2, 4, 8
Synchronize
Detect
1
0
2
T1OSO/T13CKI
T1OSI
1
0
TMR1ON
TMR1L
Set
TMR1IF
on Overflow
TMR1
High Byte
Clear TMR1
(ECCPx Special Event Trigger)
Timer1 Oscillator
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
On/Off
Timer1
Timer1 Clock Input
T1SYNC
TMR1CS
T1CKPS1:T1CKPS0
Sleep Input
T1OSCEN(1)
FOSC/4
Internal
Clock
Prescaler
1, 2, 4, 8
Synchronize
Detect
1
0
2
T1OSO/T13CKI
T1OSI
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
1
0
TMR1L
Internal Data Bus
8
Set
TMR1IF
on Overflow
TMR1
TMR1H
High Byte
88
8
Read TMR1L
Write TMR1L
8
TMR1ON
Clear TMR1
(ECCPx Special Event Trigger)
Timer1 Oscillator
On/Off
Timer1
Timer1 Clock Input
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 183
PIC18F87J11 FAMILY
13.2 Timer1 16-Bit Read/Write Mode
Timer1 can be configured for 16-bit reads and writes
(see Figure 13-2). When the RD16 control bit,
T1CON<7>, is set, the address for TMR1H is mapped
to a buffer register for the high byte of Timer1. A read
from TMR1L will load the contents of the high byte of
Timer1 into the Timer1 High Byte Buffer register. This
provides the user with the ability to accurately read all
16 bits of Timer1 without having to determine whether
a read of the high byte, followed by a read of the low
byte, has become invalid due to a rollover between
reads.
A write to the high byte of Timer1 must also take place
through the TMR1H Buffer register. The Timer1 high
byte is updated with the contents of TMR1H when a
write occurs to TMR1L. This allows a user to write all
16 bits to both the high and low bytes of Timer1 at once.
The high byte of Timer1 is not directly readable or
writable in this mode. All reads and writes must take
place through the Timer1 High Byte Buffer register.
Writes to TMR1H do not clear the Timer1 prescaler.
The prescaler is only cleared on writes to TMR1L.
13.3 Timer1 Oscillator
An on-chip crystal oscillator circuit is incorporated
between pins T1OSI (input) and T1OSO (amplifier
output). It is enabled by setting the Timer1 Oscillator
Enable bit, T1OSCEN (T1CON<3>). The oscillator is a
low-power circuit rated for 32 kHz crystals. It will
continue to run during all power-managed modes. The
circuit for a typical LP oscillator is shown in Figure 13-3.
Table 13-1 shows the capacitor selection for the Timer1
oscillator.
The user must provide a software time delay to ensure
proper start-up of the Timer1 oscillator.
FIGURE 13-3: EXTERNAL
COMPONENTS FOR THE
TIMER1 LP OSCILLATOR
TABLE 13-1: CAPACITOR SELECTION FOR
THE TIMER OSCILLATOR(2,3,4)
13.3.1 USING TIMER1 AS A
CLOCK SOURCE
The Timer1 oscillator is also available as a clock source
in power-managed modes. By setting the clock select
bits, SCS1:SCS0 (OSCCON<1:0>), to ‘01’, the device
switches to SEC_RUN mode; both the CPU and
peripherals are clocked from the Timer1 oscillator. If the
IDLEN bit (OSCCON<7>) is cleared and a SLEEP
instruction is executed, the device enters SEC_IDLE
mode. Additional details are available in Section 3.0
“Power-Managed Modes”.
Whenever the Timer1 oscillator is providing the clock
source, the Timer1 system clock status flag, T1RUN
(T1CON<6>), is set. This can be used to determine the
controller’s current clocking mode. It can also indicate
the clock source being currently used by the Fail-Safe
Clock Monitor. If the Clock Monitor is enabled and the
Timer1 oscillator fails while providing the clock, polling
the T1RUN bit will indicate whether the clock is being
provided by the Timer1 oscillator or another source.
13.3.2 TIMER1 OSCILLATOR LAYOUT
CONSIDERATIONS
The Timer1 oscillator circuit draws very little power
during operation. Due to the low-power nature of the
oscillator, it may also be sensitive to rapidly changing
signals in close proximity.
The oscillator circuit, shown in Figure 13-3, should be
located as close as possible to the microcontroller.
There should be no circuits passing within the oscillator
circuit boundaries other than VSS or VDD.
Note: See the Notes with Table 13-1 for additional
information about capacitor selection.
C1
C2
XTAL
PIC18F87J11
T1OSI
T1OSO
32.768 kHz
27 pF
27 pF
Oscillator
Type Freq. C1 C2
LP 32 kHz 27 pF(1) 27 pF(1)
Note 1: Microchip suggests these values as a
starting point in validating the oscillator
circuit.
2: Higher capacitance increases the stability
of the oscillator but also increases the
start-up time.
3: Since each resonator/crystal has its own
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate values of external
components.
4: Capacitor values are for design guidance
only.
PIC18F87J11 FAMILY
DS39778C-page 184 Preliminary © 2008 Microchip Technology Inc.
If a high-speed circuit must be located near the oscilla-
tor (such as the ECCP1 pin in Output Compare or PWM
mode, or the primary oscillator using the OSC2 pin), a
grounded guard ring around the oscillator circuit, as
shown in Figure 13-4, may be helpful when used on a
single-sided PCB or in addition to a ground plane.
FIGURE 13-4: OSCILLATOR CIRCUIT
WITH GROUNDED
GUARD RING
13.4 Timer1 Interrupt
The TMR1 register pair (TMR1H:TMR1L) increments
from 0000h to FFFFh and rolls over to 0000h. The
Timer1 interrupt, if enabled, is generated on overflow
which is latched in interrupt flag bit, TMR1IF
(PIR1<0>). This interrupt can be enabled or disabled
by setting or clearing the Timer1 Interrupt Enable bit,
TMR1IE (PIE1<0>).
13.5 Resetting Timer1 Using the
ECCPx Special Event Trigger
If ECCP1 or ECCP2 is configured to use Timer1 and to
generate a Special Event Trigger in Compare mode
(CCPxM3:CCPxM0 = 1011), this signal will reset
Timer3. The trigger from ECCP2 will also start an A/D
conversion if the A/D module is enabled (see
Section 18.2.1 “Special Event Trigger” for more
information).
The module must be configured as either a timer or a
synchronous counter to take advantage of this feature.
When used this way, the CCPRxH:CCPRxL register
pair effectively becomes a period register for Timer1.
If Timer1 is running in Asynchronous Counter mode,
this Reset operation may not work.
In the event that a write to Timer1 coincides with a
Special Event Trigger, the write operation will take
precedence.
13.6 Using Timer1 as a Real-Time Clock
Adding an external LP oscillator to Timer1 (such as the
one described in Section 13.3 “Timer1 Oscillator”)
gives users the option to include RTC functionality to
their applications. This is accomplished with an
inexpensive watch crystal to provide an accurate time
base and several lines of application code to calculate
the time. When operating in Sleep mode and using a
battery or supercapacitor as a power source, it can
completely eliminate the need for a separate RTC
device and battery backup.
The application code routine, RTCisr, shown in
Example 13-1, demonstrates a simple method to
increment a counter at one-second intervals using an
Interrupt Service Routine. Incrementing the TMR1
register pair to overflow triggers the interrupt and calls
the routine which increments the seconds counter by
one. Additional counters for minutes and hours are
incremented as the previous counter overflows.
Since the register pair is 16 bits wide, counting up to
overflow the register directly from a 32.768 kHz clock
would take 2 seconds. To force the overflow at the
required one-second intervals, it is necessary to pre-
load it. The simplest method is to set the MSb of
TMR1H with a BSF instruction. Note that the TMR1L
register is never preloaded or altered; doing so may
introduce cumulative error over many cycles.
For this method to be accurate, Timer1 must operate in
Asynchronous mode and the Timer1 overflow interrupt
must be enabled (PIE1<0> = 1), as shown in the
routine, RTCinit. The Timer1 oscillator must also be
enabled and running at all times.
VDD
OSC1
VSS
OSC2
RC0
RC1
RC2
Note: Not drawn to scale.
Note: The Special Event Triggers from the
ECCPx module will not set the TMR1IF
interrupt flag bit (PIR1<0>).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 185
PIC18F87J11 FAMILY
13.7 Considerations in Asynchronous
Counter Mode
Following a Timer1 interrupt and an update to the
TMR1 registers, the Timer1 module uses a falling edge
on its clock source to trigger the next register update on
the rising edge. If the update is completed after the
clock input has fallen, the next rising edge will not be
counted.
If the application can reliably update TMR1 before the
timer input goes low, no additional action is needed.
Otherwise, an adjusted update can be performed fol-
lowing a later Timer1 increment. This can be done by
monitoring TMR1L within the interrupt routine until it
increments, and then updating the TMR1H:TMR1L reg-
ister pair while the clock is low, or one-half of the period
of the clock source. Assuming that Timer1 is being
used as a Real-Time Clock, the clock source is a
32.768 kHz crystal oscillator. In this case, one-half
period of the clock is 15.25 μs.
The Real-Time Clock application code in Example 13-1
shows a typical ISR for Timer1, as well as the optional
code required if the update cannot be done reliably
within the required interval.
EXAMPLE 13-1: IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE
RTCinit
MOVLW 80h ; Preload TMR1 register pair
MOVWF TMR1H ; for 1 second overflow
CLRF TMR1L
MOVLW b’00001111’ ; Configure for external clock,
MOVWF T1CON ; Asynchronous operation, external oscillator
CLRF secs ; Initialize timekeeping registers
CLRF mins ;
MOVLW .12
MOVWF hours
BSF PIE1, TMR1IE ; Enable Timer1 interrupt
RETURN
RTCisr
; Insert the next 4 lines of code when TMR1
; can not be reliably updated before clock pulse goes low
BTFSC TMR1L,0 ; wait for TMR1L to become clear
BRA $-2 ; (may already be clear)
BTFSS TMR1L,0 ; wait for TMR1L to become set
BRA $-2 ; TMR1 has just incremented
; If TMR1 update can be completed before clock pulse goes low
; Start ISR here
BSF TMR1H, 7 ; Preload for 1 sec overflow
BCF PIR1, TMR1IF ; Clear interrupt flag
INCF secs, F ; Increment seconds
MOVLW .59 ; 60 seconds elapsed?
CPFSGT secs
RETURN ; No, done
CLRF secs ; Clear seconds
INCF mins, F ; Increment minutes
MOVLW .59 ; 60 minutes elapsed?
CPFSGT mins
RETURN ; No, done
CLRF mins ; clear minutes
INCF hours, F ; Increment hours
MOVLW .23 ; 24 hours elapsed?
CPFSGT hours
RETURN ; No, done
CLRF hours ; Reset hours
RETURN ; Done
PIC18F87J11 FAMILY
DS39778C-page 186 Preliminary © 2008 Microchip Technology Inc.
TABLE 13-2: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
TMR1L(1) Timer1 Register Low Byte 56
TMR1H(1) Timer1 Register High Byte 56
T1CON(1) RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 56
Legend: Shaded cells are not used by the Timer1 module.
Note 1: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 187
PIC18F87J11 FAMILY
14.0 TIMER2 MODULE
The Timer2 module incorporates the following features:
8-Bit Timer and Period registers (TMR2 and PR2,
respectively)
Readable and writable (both registers)
Software programmable prescaler
(1:1, 1:4 and 1:16)
Software programmable postscaler
(1:1 through 1:16)
Interrupt on TMR2 to PR2 match
Optional use as the shift clock for the
MSSP modules
The module is controlled through the T2CON register
(Register 14-1) which enables or disables the timer and
configures the prescaler and postscaler. Timer2 can be
shut off by clearing control bit, TMR2ON (T2CON<2>),
to minimize power consumption.
A simplified block diagram of the module is shown in
Figure 14-1.
14.1 Timer2 Operation
In normal operation, TMR2 is incremented from 00h on
each clock (FOSC/4). A 4-bit counter/prescaler on the
clock input gives direct input, divide-by-4 and
divide-by-16 prescale options. These are selected by
the prescaler control bits, T2CKPS1:T2CKPS0
(T2CON<1:0>). The value of TMR2 is compared to that
of the Period register, PR2, on each clock cycle. When
the two values match, the comparator generates a
match signal as the timer output. This signal also resets
the value of TMR2 to 00h on the next cycle and drives
the output counter/postscaler (see Section 14.2
“Timer2 Interrupt”).
The TMR2 and PR2 registers are both directly readable
and writable. The TMR2 register is cleared on any
device Reset, while the PR2 register initializes at FFh.
Both the prescaler and postscaler counters are cleared
on the following events:
a write to the TMR2 register
a write to the T2CON register
any device Reset (Power-on Reset, MCLR Reset,
Watchdog Timer Reset or Brown-out Reset)
TMR2 is not cleared when T2CON is written.
REGISTER 14-1: T2CON: TIMER2 CONTROL REGISTER
U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as0
bit 6-3 T2OUTPS3:T2OUTPS0: Timer2 Output Postscale Select bits
0000 = 1:1 Postscale
0001 = 1:2 Postscale
1111 = 1:16 Postscale
bit 2 TMR2ON: Timer2 On bit
1 = Timer2 is on
0 = Timer2 is off
bit 1-0 T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits
00 = Prescaler is 1
01 = Prescaler is 4
1x = Prescaler is 16
PIC18F87J11 FAMILY
DS39778C-page 188 Preliminary © 2008 Microchip Technology Inc.
14.2 Timer2 Interrupt
Timer2 can also generate an optional device interrupt.
The Timer2 output signal (TMR2 to PR2 match) pro-
vides the input for the 4-bit output counter/postscaler.
This counter generates the TMR2 match interrupt flag
which is latched in TMR2IF (PIR1<1>). The interrupt is
enabled by setting the TMR2 Match Interrupt Enable
bit, TMR2IE (PIE1<1>).
A range of 16 postscale options (from 1:1 through 1:16
inclusive) can be selected with the postscaler control
bits, T2OUTPS3:T2OUTPS0 (T2CON<6:3>).
14.3 Timer2 Output
The unscaled output of TMR2 is available primarily to
the ECCPx/CCPx modules, where it is used as a time
base for operations in PWM mode.
Timer2 can be optionally used as the shift clock source
for the MSSP modules operating in SPI mode.
Additional information is provided in Section 19.0
“Master Synchronous Serial Port (MSSP) Module”.
FIGURE 14-1: TIMER2 BLOCK DIAGRAM
TABLE 14-1: REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
TMR2(1) Timer2 Register 56
T2CON T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 56
PR2(1) Timer2 Period Register 56
Legend: = unimplemented, read as ‘0’. Shaded cells are not used by the Timer2 module.
Note 1: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
Comparator
TMR2 Output
TMR2
Postscaler
Prescaler PR2
2
FOSC/4
1:1 to 1:16
1:1, 1:4, 1:16
4
T2OUTPS3:T2OUTPS0
T2CKPS1:T2CKPS0
Set TMR2IF
Internal Data Bus
8
Reset
TMR2/PR2
8
8
(to PWM or MSSP)
Match
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 189
PIC18F87J11 FAMILY
15.0 TIMER3 MODULE
The Timer3 timer/counter module incorporates these
features:
Software selectable operation as a 16-bit timer or
counter
Readable and writable 8-bit registers (TMR3H
and TMR3L)
Selectable clock source (internal or external) with
device clock or Timer1 oscillator internal options
Interrupt-on-overflow
Module Reset on ECCPx Special Event Trigger
A simplified block diagram of the Timer3 module is
shown in Figure 15-1. A block diagram of the module’s
operation in Read/Write mode is shown in Figure 15-2.
The Timer3 module is controlled through the T3CON
register (Register 15-1). It also selects the clock source
options for the CCP and ECCP modules; see
Section 17.1.1 “CCP Modules and Timer
Resources” for more information.
REGISTER 15-1: T3CON: TIMER3 CONTROL REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 RD16: 16-Bit Read/Write Mode Enable bit
1 = Enables register read/write of Timer3 in one 16-bit operation
0 = Enables register read/write of Timer3 in two 8-bit operations
bit 6,3 T3CCP2:T3CCP1: Timer3 and Timer1 to ECCPx/CCPx Enable bits
11 = Timer3 and Timer4 are the clock sources for all ECCPx/CCPx modules
10 = Timer3 and Timer4 are the clock sources for ECCP3, CCP4 and CCP5;
Timer1 and Timer2 are the clock sources for ECCP1 and ECCP2
01 = Timer3 and Timer4 are the clock sources for ECCP2, ECCP3, CCP4 and CCP5;
Timer1 and Timer2 are the clock sources for ECCP1
00 = Timer1 and Timer2 are the clock sources for all ECCPx/CCPx modules
bit 5-4 T3CKPS1:T3CKPS0: Timer3 Input Clock Prescale Select bits
11 = 1:8 Prescale value
10 = 1:4 Prescale value
01 = 1:2 Prescale value
00 = 1:1 Prescale value
bit 2 T3SYNC: Timer3 External Clock Input Synchronization Control bit
(Not usable if the device clock comes from Timer1/Timer3.)
When TMR3CS = 1:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
When TMR3CS = 0:
This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0.
bit 1 TMR3CS: Timer3 Clock Source Select bit
1 = External clock input from Timer1 oscillator or T13CKI (on the rising edge after the first
falling edge)
0 = Internal clock (FOSC/4)
bit 0 TMR3ON: Timer3 On bit
1 = Enables Timer3
0 = Stops Timer3
PIC18F87J11 FAMILY
DS39778C-page 190 Preliminary © 2008 Microchip Technology Inc.
15.1 Timer3 Operation
Timer3 can operate in one of three modes:
•Timer
Synchronous Counter
Asynchronous Counter
The operating mode is determined by the clock select
bit, TMR3CS (T3CON<1>). When TMR3CS is cleared
(= 0), Timer3 increments on every internal instruction
cycle (FOSC/4). When the bit is set, Timer3 increments
on every rising edge of the Timer1 external clock input
or the Timer1 oscillator, if enabled.
As with Timer1, the RC1/T1OSI and
RC0/T1OSO/T13CKI pins become inputs when the
Timer1 oscillator is enabled. This means the values of
TRISC<1:0> are ignored and the pins are read as0’.
FIGURE 15-1: TIMER3 BLOCK DIAGRAM
FIGURE 15-2: TIMER3 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
T3SYNC
TMR3CS
T3CKPS1:T3CKPS0
Sleep Input
T1OSCEN(1)
FOSC/4
Internal
Clock
Prescaler
1, 2, 4, 8
Synchronize
Detect
1
0
2
T1OSO/T13CKI
T1OSI
1
0
TMR3ON
TMR3L Set
TMR3IF
on Overflow
TMR3
High Byte
Timer1 Oscillator
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
On/Off
Timer3
ECCPx Special Event Trigger
ECCPx/CCPx Select from T3CON<6,3>
Clear TMR3
Timer1 Clock Input
T3SYNC
TMR3CS
T3CKPS1:T3CKPS0
Sleep Input
T1OSCEN(1)
FOSC/4
Internal
Clock
Prescaler
1, 2, 4, 8
Synchronize
Detect
1
0
2
T13CKI/T1OSO
T1OSI
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
1
0
TMR3L
Internal Data Bus
8
Set
TMR3IF
on Overflow
TMR3
TMR3H
High Byte
88
8
Read TMR1L
Write TMR1L
8
TMR3ON
ECCPx Special Event Trigger
Timer1 Oscillator
On/Off
Timer3
Timer1 Clock Input
ECCPx/CCPx Select from T3CON<6,3>
Clear TMR3
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 191
PIC18F87J11 FAMILY
15.2 Timer3 16-Bit Read/Write Mode
Timer3 can be configured for 16-bit reads and writes
(see Figure 15-2). When the RD16 control bit
(T3CON<7>) is set, the address for TMR3H is mapped
to a buffer register for the high byte of Timer3. A read
from TMR3L will load the contents of the high byte of
Timer3 into the Timer3 High Byte Buffer register. This
provides the user with the ability to accurately read all
16 bits of Timer1 without having to determine whether
a read of the high byte, followed by a read of the low
byte, has become invalid due to a rollover between
reads.
A write to the high byte of Timer3 must also take place
through the TMR3H Buffer register. The Timer3 high
byte is updated with the contents of TMR3H when a
write occurs to TMR3L. This allows a user to write all
16 bits to both the high and low bytes of Timer3 at once.
The high byte of Timer3 is not directly readable or
writable in this mode. All reads and writes must take
place through the Timer3 High Byte Buffer register.
Writes to TMR3H do not clear the Timer3 prescaler.
The prescaler is only cleared on writes to TMR3L.
15.3 Using the Timer1 Oscillator as the
Timer3 Clock Source
The Timer1 internal oscillator may be used as the clock
source for Timer3. The Timer1 oscillator is enabled by
setting the T1OSCEN (T1CON<3>) bit. To use it as the
Timer3 clock source, the TMR3CS bit must also be set.
As previously noted, this also configures Timer3 to
increment on every rising edge of the oscillator source.
The Timer1 oscillator is described in Section 13.0
“Timer1 Module”.
15.4 Timer3 Interrupt
The TMR3 register pair (TMR3H:TMR3L) increments
from 0000h to FFFFh and overflows to 0000h. The
Timer3 interrupt, if enabled, is generated on overflow
and is latched in interrupt flag bit, TMR3IF (PIR2<1>).
This interrupt can be enabled or disabled by setting or
clearing the Timer3 Interrupt Enable bit, TMR3IE
(PIE2<1>).
15.5 Resetting Timer3 Using the
ECCPx Special Event Trigger
If ECCP1 or ECCP2 is configured to use Timer3 and to
generate a Special Event Trigger in Compare mode
(CCPxM3:CCPxM0 = 1011), this signal will reset
Timer3. The trigger from ECCP2 will also start an A/D
conversion if the A/D module is enabled (see
Section 18.2.1 “Special Event Trigger” for more
information).
The module must be configured as either a timer or
synchronous counter to take advantage of this feature.
When used this way, the CCPRxH:CCPRxL register
pair effectively becomes a period register for Timer3.
If Timer3 is running in Asynchronous Counter mode,
the Reset operation may not work.
In the event that a write to Timer3 coincides with a
Special Event Trigger from an ECCPx module, the
write will take precedence.
TABLE 15-1: REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER
Note: The Special Event Triggers from the
ECCPx module will not set the TMR3IF
interrupt flag bit (PIR1<0>).
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR2 OSCFIF CM2IF CM1IF BCL1IF LVDIF TMR3IF CCP2IF 58
PIE2 OSCFIE CM2IE CM1IE BCL1IE LVDIE TMR3IE CCP2IE 58
IPR2 OSCFIP CM2IP CM1IP BCL1IP LVDIP TMR3IP CCP2IP 58
TMR3L Timer3 Register Low Byte 59
TMR3H Timer3 Register High Byte 59
T1CON(1) RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 56
T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 59
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer3 module.
Note 1: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
PIC18F87J11 FAMILY
DS39778C-page 192 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 193
PIC18F87J11 FAMILY
16.0 TIMER4 MODULE
The Timer4 timer module has the following features:
8-bit timer register (TMR4)
8-bit period register (PR4)
Readable and writable (both registers)
Software programmable prescaler (1:1, 1:4, 1:16)
Software programmable postscaler (1:1 to 1:16)
Interrupt on TMR4 match of PR4
Timer4 has a control register shown in Register 16-1.
Timer4 can be shut off by clearing control bit, TMR4ON
(T4CON<2>), to minimize power consumption. The
prescaler and postscaler selection of Timer4 are also
controlled by this register. Figure 16-1 is a simplified
block diagram of the Timer4 module.
16.1 Timer4 Operation
Timer4 can be used as the PWM time base for the
PWM mode of the ECCPx/CCPx modules. The TMR4
register is readable and writable and is cleared on any
device Reset. The input clock (FOSC/4) has a prescale
option of 1:1, 1:4 or 1:16, selected by control bits
T4CKPS1:T4CKPS0 (T4CON<1:0>). The match out-
put of TMR4 goes through a 4-bit postscaler (which
gives a 1:1 to 1:16 scaling inclusive) to generate a
TMR4 interrupt, latched in flag bit, TMR4IF (PIR3<3>).
The prescaler and postscaler counters are cleared
when any of the following occurs:
a write to the TMR4 register
a write to the T4CON register
any device Reset (Power-on Reset, MCLR Reset,
Watchdog Timer Reset or Brown-out Reset)
TMR4 is not cleared when T4CON is written.
REGISTER 16-1: T4CON: TIMER4 CONTROL REGISTER
U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as0
bit 6-3 T4OUTPS3:T4OUTPS0: Timer4 Output Postscale Select bits
0000 = 1:1 Postscale
0001 = 1:2 Postscale
1111 = 1:16 Postscale
bit 2 TMR4ON: Timer4 On bit
1 = Timer4 is on
0 = Timer4 is off
bit 1-0 T4CKPS1:T4CKPS0: Timer4 Clock Prescale Select bits
00 = Prescaler is 1
01 = Prescaler is 4
1x = Prescaler is 16
PIC18F87J11 FAMILY
DS39778C-page 194 Preliminary © 2008 Microchip Technology Inc.
16.2 Timer4 Interrupt
The Timer4 module has an 8-bit period register, PR4,
which is both readable and writable. Timer4 increments
from 00h until it matches PR4 and then resets to 00h on
the next increment cycle. The PR4 register is initialized
to FFh upon Reset.
16.3 Output of TMR4
The output of TMR4 (before the postscaler) is used
only as a PWM time base for the ECCPx/CCPx mod-
ules. It is not used as a baud rate clock for the MSSP
modules as is the Timer2 output.
FIGURE 16-1: TIMER4 BLOCK DIAGRAM
TABLE 16-1: REGISTERS ASSOCIATED WITH TIMER4 AS A TIMER/COUNTER
Comparator
TMR4 Output
TMR4
Postscaler
Prescaler PR4
2
FOSC/4
1:1 to 1:16
1:1, 1:4, 1:16
4
T4OUTPS3:T4OUTPS0
T4CKPS1:T4CKPS0
Set TMR4IF
Internal Data Bus
8
Reset
TMR4/PR4
8
8
(to PWM)
Match
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
TMR4 Timer4 Register 59
T4CON T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0 59
PR4 Timer4 Period Register 59
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer4 module.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 195
PIC18F87J11 FAMILY
17.0 CAPTURE/COMPARE/PWM
(CCP) MODULES
Members of the PIC18F87J11 family of devices all have
a total of five CCP (Capture/Compare/PWM) modules.
Two of these (CCP4 and CCP5) implement standard
Capture, Compare and Pulse-Width Modulation (PWM)
modes and are discussed in this section. The other three
modules (ECCP1, ECCP2, ECCP3) implement
standard Capture and Compare modes, as well as
Enhanced PWM modes. These are discussed in
Section 18.0 “Enhanced Capture/Compare/PWM
(ECCP) Module”.
Each CCP/ECCP module contains a 16-bit register
which can operate as a 16-bit Capture register, a 16-bit
Compare register or a PWM Master/Slave Duty Cycle
register. For the sake of clarity, all CCP module opera-
tion in the following sections is described with respect
to CCP4, but is equally applicable to CCP5.
Capture and Compare operations described in this
chapter apply to all standard and Enhanced CCP
modules. The operations of PWM mode, described in
Section 17.4 “PWM Mode”, apply to CCP4 and CCP5
only.
Note: Throughout this section and Section 18.0
“Enhanced Capture/Compare/PWM (ECCP)
Module”, references to register and bit names
that may be associated with a specific CCP
module are referred to generically by the use of
‘x’ or ‘y’ in place of the specific module number.
Thus, “CCPxCON” might refer to the control
register for ECCP1, ECCP2, ECCP3, CCP4 or
CCP5.
REGISTER 17-1: CCPxCON: CCPx CONTROL REGISTER (CCP4 MODULE, CCP5 MODULE)
U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
CCPxX CCPxY CCPxM3 CCPxM2 CCPxM1 CCPxM0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 Unimplemented: Read as ‘0
bit 5-4 CCPx<X:Y>: PWM Duty Cycle bit 1 and bit 0 for CCPx Module
Capture mode:
Unused.
Compare mode:
Unused.
PWM mode:
These bits are the two Least Significant bits (bit 1 and bit 0) of the 10-bit PWM duty cycle. The eight Most
Significant bits (DCx9:DCx2) of the duty cycle are found in CCPRxL.
bit 3-0 CCPxM3:CCPxM0: CCPx Module Mode Select bits
0000 = Capture/Compare/PWM disabled (resets CCPx module)
0001 = Reserved
0010 = Compare mode, toggle output on match (CCPxIF bit is set)
0011 = Reserved
0100 = Capture mode: every falling edge
0101 = Capture mode: every rising edge
0110 = Capture mode: every 4th rising edge
0111 = Capture mode: every 16th rising edge
1000 = Compare mode: initialize CCPx pin low; on compare match, force CCPx pin high (CCPxIF bit is set)
1001 = Compare mode: initialize CCPx pin high; on compare match, force CCPx pin low (CCPxIF bit is set)
1010 = Compare mode: generate software interrupt on compare match (CCPxIF bit is set,
CCPx pin reflects I/O state)
1011 = Compare mode: trigger special event, reset timer, start A/D conversion on CCPx match
(CCPxIF bit is set)(1)
11xx =PWM mode
PIC18F87J11 FAMILY
DS39778C-page 196 Preliminary © 2008 Microchip Technology Inc.
17.1 CCP Module Configuration
Each Capture/Compare/PWM module is associated
with a control register (generically, CCPxCON) and a
data register (CCPRx). The data register, in turn, is
comprised of two 8-bit registers: CCPRxL (low byte)
and CCPRxH (high byte). All registers are both
readable and writable.
17.1.1 CCP MODULES AND TIMER
RESOURCES
The ECCP/CCP modules utilize Timers 1, 2, 3 or 4,
depending on the mode selected. Timer1 and Timer3
are available to modules in Capture or Compare
modes, while Timer2 and Timer4 are available for
modules in PWM mode.
TABLE 17-1: CCP MODE – TIMER
RESOURCE
The assignment of a particular timer to a module is
determined by the timer to CCP enable bits in the
T3CON register (Register 15-1, page 189). Depending
on the configuration selected, up to four timers may be
active at once, with modules in the same configuration
(Capture/Compare or PWM) sharing timer resources.
The possible configurations are shown in Figure 17-1.
17.1.2 OPEN-DRAIN OUTPUT OPTION
When operating in Output mode (i.e., in Compare or
PWM modes), the drivers for the CCP pins can be
optionally configured as open-drain outputs. This feature
allows the voltage level on the pin to be pulled to a higher
level through an external pull-up resistor, and allows the
output to communicate with external circuits without the
need for additional level shifters. For more information,
see Section 10.1.4 “Open-Drain Outputs”.
The open-drain output option is controlled by the bits in
the ODCON1 register. Setting the appropriate bit con-
figures the pin for the corresponding module for
open-drain operation. The ODCON1 memory shares
the same address space as TMR1H. The ODCON1
register can be accessed by setting the ADSHR bit in
the WDTCON register (WDTCON<4>).
FIGURE 17-1: ECCPx/CCPx AND TIMER INTERCONNECT CONFIGURATIONS
CCP Mode Timer Resource
Capture
Compare
PWM
Timer1 or Timer3
Timer1 or Timer3
Timer2 or Timer4
TMR1
CCP5
TMR2
TMR3
TMR4
CCP4
ECCP3
ECCP2
ECCP1
TMR1
TMR2
TMR3
CCP5
TMR4
CCP4
ECCP3
ECCP2
ECCP1
TMR1
TMR2
TMR3
CCP5
TMR4
CCP4
ECCP3
ECCP2
ECCP1
TMR1
TMR2
TMR3
CCP5
TMR4
CCP4
ECCP3
ECCP2
ECCP1
T3CCP<2:1> = 00 T3CCP<2:1> = 01 T3CCP<2:1> = 10 T3CCP<2:1> = 11
Timer1 is used for all Capture
and Compare operations for
all CCP modules. Timer2 is
used for PWM operations for
all CCP modules. Modules
may share either timer
resource as a common time
base.
Timer3 and Timer4 are not
available.
Timer1 and Timer2 are used
for Capture and Compare or
PWM operations for ECCP1
only (depending on selected
mode).
All other modules use either
Timer3 or Timer4. Modules
may share either timer
resource as a common time
base if they are in
Capture/Compare or PWM
modes.
Timer1 and Timer2 are used
for Capture and Compare or
PWM operations for ECCP1
and ECCP2 only (depending
on the mode selected for each
module). Both modules may
use a timer as a common time
base if they are both in
Capture/Compare or PWM
modes.
The other modules use either
Timer3 or Timer4. Modules
may share either timer
resource as a common time
base if they are in
Capture/Compare or PWM
modes.
Timer3 is used for all Capture
and Compare operations for
all CCP modules. Timer4 is
used for PWM operations for
all CCP modules. Modules
may share either timer
resource as a common time
base.
Timer1 and Timer2 are not
available.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 197
PIC18F87J11 FAMILY
17.2 Capture Mode
In Capture mode, the CCPRxH:CCPRxL register pair
captures the 16-bit value of the TMR1 or TMR3
registers when an event occurs on the corresponding
CCP pin. An event is defined as one of the following:
every falling edge
every rising edge
every 4th rising edge
every 16th rising edge
The event is selected by the mode select bits,
CCPxM3:CCPxM0 (CCPxCON<3:0>). When a capture
is made, the interrupt request flag bit, CCPxIF, is set; it
must be cleared in software. If another capture occurs
before the value in register CCPRx is read, the old
captured value is overwritten by the new captured value.
17.2.1 CCP PIN CONFIGURATION
In Capture mode, the appropriate CCP pin should be
configured as an input by setting the corresponding
TRIS direction bit.
17.2.2 TIMER1/TIMER3 MODE SELECTION
The timers that are to be used with the capture feature
(Timer1 and/or Timer3) must be running in Timer mode or
Synchronized Counter mode. In Asynchronous Counter
mode, the capture operation will not work. The timer to be
used with each CCP module is selected in the T3CON
register (see Section 17.1.1 “CCP Modules and Timer
Resources”).
17.2.3 SOFTWARE INTERRUPT
When the Capture mode is changed, a false capture
interrupt may be generated. The user should keep the
CCPxIE interrupt enable bit clear to avoid false
interrupts. The interrupt flag bit, CCPxIF, should also be
cleared following any such change in operating mode.
17.2.4 CCP PRESCALER
There are four prescaler settings in Capture mode.
They are specified as part of the operating mode
selected by the mode select bits (CCPxM3:CCPxM0).
Whenever the CCP module is turned off or Capture
mode is disabled, the prescaler counter is cleared. This
means that any Reset will clear the prescaler counter.
Switching from one capture prescaler to another may
generate an interrupt. Also, the prescaler counter will
not be cleared; therefore, the first capture may be from
a non-zero prescaler. Example 17-1 shows the
recommended method for switching between capture
prescalers. This example also clears the prescaler
counter and will not generate the “false” interrupt.
EXAMPLE 17-1: CHANGING BETWEEN
CAPTURE PRESCALERS
(CCP5 SHOWN)
FIGURE 17-2: CAPTURE MODE OPERATION BLOCK DIAGRAM
Note: If RG4/CCP5 is configured as an output, a
write to the port can cause a capture
condition.
CLRF CCP5CON ; Turn CCP module off
MOVLW NEW_CAPT_PS ; Load WREG with the
; new prescaler mode
; value and CCP ON
MOVWF CCP5CON ; Load CCP5CON with
; this value
CCPR4H CCPR4L
TMR1H TMR1L
Set CCP4IF
TMR3
Enable
Q1:Q4
CCP4CON<3:0>
CCP4 pin
Prescaler
÷ 1, 4, 16
and
Edge Detect
TMR1
Enable
T3CCP2
T3CCP2
CCPR5H CCPR5L
TMR1H TMR1L
Set CCP5IF
TMR3
Enable
CCP5CON<3:0>
CCP5 pin
Prescaler
÷ 1, 4, 16
TMR3H TMR3L
TMR1
Enable
T3CCP2
T3CCP1
T3CCP2
T3CCP1
TMR3H TMR3L
and
Edge Detect
4
4
4
PIC18F87J11 FAMILY
DS39778C-page 198 Preliminary © 2008 Microchip Technology Inc.
17.3 Compare Mode
In Compare mode, the 16-bit CCPRx register value is
constantly compared against either the TMR1 or TMR3
register pair value. When a match occurs, the CCP pin
can be:
driven high
driven low
toggled (high-to-low or low-to-high)
remains unchanged (that is, reflects the state of
the I/O latch)
The action on the pin is based on the value of the mode
select bits (CCPxM3:CCPxM0). At the same time, the
interrupt flag bit, CCPxIF, is set.
17.3.1 CCP PIN CONFIGURATION
The user must configure the CCP pin as an output by
clearing the appropriate TRIS bit.
17.3.2 TIMER1/TIMER3 MODE SELECTION
Timer1 and/or Timer3 must be running in Timer mode
or Synchronized Counter mode if the CCP module is
using the compare feature. In Asynchronous Counter
mode, the compare operation may not work.
17.3.3 SOFTWARE INTERRUPT MODE
When the Generate Software Interrupt mode is chosen
(CCPxM3:CCPxM0 = 1010), the corresponding CCP
pin is not affected. Only a CCP interrupt is generated,
if enabled, and the CCPxIE bit is set.
FIGURE 17-3: COMPARE MODE OPERATION BLOCK DIAGRAM
Note: Clearing the CCP5CON register will force
the RG4 compare output latch (depend-
ing on device configuration) to the default
low level. This is not the PORTB or
PORTC I/O data latch.
CCPR4H CCPR4L
TMR1H TMR1L
Comparator QS
R
Output
Logic
Set CCP4IF
CCP4 pin
TRIS
CCP4CON<3:0>
Output Enable
TMR3H TMR3L
CCPR5H CCPR5L
Comparator
1
0
T3CCP2
T3CCP1
Set CCP5IF
1
0
Compare
4
Q
S
R
Output
Logic
CCP5 pin
TRIS
CCP5CON<3:0>
Output Enable
4
Match
Compare
Match
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 199
PIC18F87J11 FAMILY
TABLE 17-2: REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
RCON IPEN CM RI TO PD POR BOR 56
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR2 OSCFIF CM2IF CM1IF BCL1IF LVDIF TMR3IF CCP2IF 58
PIE2 OSCFIE CM2IE CM1IE BCL1IE LVDIE TMR3IE CCP2IE 58
IPR2 OSCFIP CM2IP CM1IP BCL1IP LVDIP TMR3IP CCP2IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
TRISG TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 58
TMR1L(1) Timer1 Register Low Byte 56
TMR1H(1) Timer1 Register High Byte 56
ODCON1(2) CCP5OD CCP4OD ECCP3OD ECCP2OD ECCP1OD 56
T1CON(1) RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 56
TMR3H Timer3 Register High Byte 59
TMR3L Timer3 Register Low Byte 59
T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 59
CCPR4L Capture/Compare/PWM Register 4 Low Byte 59
CCPR4H Capture/Compare/PWM Register 4 High Byte 59
CCPR5L Capture/Compare/PWM Register 5 Low Byte 59
CCPR5H Capture/Compare/PWM Register 5 High Byte 59
CCP4CON DC4B1 DC4B0 CCP4M3 CCP4M2 CCP4M1 CCP4M0 59
CCP5CON DC5B1 DC5B0 CCP5M3 CCP5M2 CCP5M1 CCP5M0 59
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by Capture/Compare, Timer1 or Timer3.
Note 1: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
2: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
PIC18F87J11 FAMILY
DS39778C-page 200 Preliminary © 2008 Microchip Technology Inc.
17.4 PWM Mode
In Pulse-Width Modulation (PWM) mode, the CCP pin
produces up to a 10-bit resolution PWM output. Since
the CCP4 and CCP5 pins are multiplexed with a
PORTG data latch, the appropriate TRISG bit must be
cleared to make the CCP4 or CCP5 pin an output.
Figure 17-4 shows a simplified block diagram of the
CCP module in PWM mode.
For a step-by-step procedure on how to set up a CCP
module for PWM operation, see Section 17.4.3
“Setup for PWM Operation”.
FIGURE 17-4: SIMPLIFIED PWM BLOCK
DIAGRAM
A PWM output (Figure 17-5) has a time base (period)
and a time that the output stays high (duty cycle).
The frequency of the PWM is the inverse of the
period (1/period).
FIGURE 17-5: PWM OUTPUT
17.4.1 PWM PERIOD
The PWM period is specified by writing to the PR2
(PR4) register. The PWM period can be calculated
using Equation 17-1:
EQUATION 17-1:
PWM frequency is defined as 1/[PWM period].
When TMR2 (TMR4) is equal to PR2 (PR4), the
following three events occur on the next increment
cycle:
TMR2 (TMR4) is cleared
The CCP pin is set (exception: if PWM duty
cycle = 0%, the CCP pin will not be set)
The PWM duty cycle is latched from CCPRxL into
CCPRxH
17.4.2 PWM DUTY CYCLE
The PWM duty cycle is specified by writing to the
CCPRxL register and to the CCPxCON<5:4> bits. Up
to 10-bit resolution is available. The CCPRxL contains
the eight MSbs and the CCPxCON<5:4> contains the
two LSbs. This 10-bit value is represented by
CCPRxL:CCPxCON<5:4>. Equation 17-2 is used to
calculate the PWM duty cycle in time.
EQUATION 17-2:
CCPRxL and CCPxCON<5:4> can be written to at any
time, but the duty cycle value is not latched into
CCPRxH until after a match between PR2 (PR4) and
TMR2 (TMR4) occurs (i.e., the period is complete). In
PWM mode, CCPRxH is a read-only register.
Note: Clearing the CCP4CON or CCP5CON
register will force the RG3 or RG4 output
latch (depending on device configuration)
to the default low level. This is not the
PORTG I/O data latch.
CCPRxL
Comparator
Comparator
PRx
CCPxCON<5:4>
QS
RCCPx
TRIS
Output Enable
CCPRxH
TMRx
2 LSbs latched
from Q clocks
Reset
Match
TMRx = PRx
Latch
09
(1)
Note 1: The two LSbs of the Duty Cycle register are held by a
2-bit latch that is part of the module’s hardware. It is
physically separate from the CCPRx registers.
Duty Cycle Register
Set CCPx pin
Duty Cycle
pin
Period
Duty Cycle
TMR2 (TMR4) = PR2 (TMR4)
TMR2 (TMR4) = Duty Cycle
TMR2 (TMR4) = PR2 (PR4)
Note: The Timer2 and Timer 4 postscalers (see
Section 14.0 “Timer2 Module” and
Section 16.0 “Timer4 Module”) are not
used in the determination of the PWM
frequency. The postscaler could be used
to have a servo update rate at a different
frequency than the PWM output.
PWM Period = [(PR2) + 1] • 4 • TOSC
(TMR2 Prescale Value)
PWM Duty Cycle = (CCPRXL:CCPXCON<5:4>) •
TOSC • (TMR2 Prescale Value)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 201
PIC18F87J11 FAMILY
The CCPRxH register and a 2-bit internal latch are
used to double-buffer the PWM duty cycle. This
double-buffering is essential for glitchless PWM
operation.
When the CCPRxH and 2-bit latch match TMR2
(TMR4), concatenated with an internal 2-bit Q clock or
2 bits of the TMR2 (TMR4) prescaler, the CCP pin is
cleared.
The maximum PWM resolution (bits) for a given PWM
frequency is given by Equation 17-3:
EQUATION 17-3:
17.4.3 SETUP FOR PWM OPERATION
The following steps should be taken when configuring
the CCP module for PWM operation:
1. Set the PWM period by writing to the PR2 (PR4)
register.
2. Set the PWM duty cycle by writing to the
CCPRxL register and CCPxCON<5:4> bits.
3. Make the CCP pin an output by clearing the
appropriate TRIS bit.
4. Set the TMR2 (TMR4) prescale value, then
enable Timer2 (Timer4) by writing to T2CON
(T4CON).
5. Configure the CCP module for PWM operation.
TABLE 17-3: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz
Note: If the PWM duty cycle value is longer than
the PWM period, the CCP pin will not be
cleared.
log(FPWM
log(2)
FOSC )bitsPWM Resolution (max) =
PWM Frequency 2.44 kHz 9.77 kHz 39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz
Timer Prescaler (1, 4, 16)1641111
PR2 Value FFh FFh FFh 3Fh 1Fh 17h
Maximum Resolution (bits) 10 10 10 8 7 6.58
PIC18F87J11 FAMILY
DS39778C-page 202 Preliminary © 2008 Microchip Technology Inc.
TABLE 17-4: REGISTERS ASSOCIATED WITH PWM, TIMER2 AND TIMER4
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
RCON IPEN CM RI TO PD POR BOR 56
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
TRISG TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 58
TMR2(1) Timer2 Register 56
PR2(1) Timer2 Period Register 56
T2CON T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 56
TMR4 Timer4 Register 59
PR4 Timer4 Period Register 59
T4CON T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0 59
CCPR4L Capture/Compare/PWM Register 4 Low Byte 59
CCPR4H Capture/Compare/PWM Register 4 High Byte 59
CCPR5L Capture/Compare/PWM Register 5 Low Byte 59
CCPR5H Capture/Compare/PWM Register 5 High Byte 59
CCP4CON DC4B1 DC4B0 CCP4M3 CCP4M2 CCP4M1 CCP4M0 59
CCP5CON DC5B1 DC5B0 CCP5M3 CCP5M2 CCP5M1 CCP5M0 59
ODCON1(2) CCP5OD CCP4OD ECCP3OD ECCP2OD ECCP1OD 56
Legend: = unimplemented, read as0. Shaded cells are not used by PWM, Timer2 or Timer4.
Note 1: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
2: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 203
PIC18F87J11 FAMILY
18.0 ENHANCED CAPTURE/
COMPARE/PWM (ECCP)
MODULE
In the PIC18F87J11 family of devices, three of the CCP
modules are implemented as standard CCP modules
with Enhanced PWM capabilities. These include the
provision for 2 or 4 output channels, user-selectable
polarity, dead-band control and automatic shutdown
and restart. The Enhanced features are discussed in
detail in Section 18.4 “Enhanced PWM Mode”.
Capture, Compare and single-output PWM functions of
the ECCP module are the same as described for the
standard CCP module.
The control register for the Enhanced CCP module is
shown in Register 18-1. It differs from the CCP4CON/
CCP5CON registers in that the two Most Significant
bits are implemented to control PWM functionality.
In addition to the expanded range of modes available
through the Enhanced CCPxCON register, the ECCP
modules each have two additional registers associated
with Enhanced PWM operation and auto-shutdown
features. They are:
ECCPxDEL (ECCPx PWM Delay)
ECCPxAS (ECCPx Auto-Shutdown Control)
REGISTER 18-1: CCPxCON: ECCPx CONTROL REGISTER (ECCP1/ECCP2/ECCP3)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PxM1 PxM0 DCxB1 DCxB0 CCPxM3 CCPxM2 CCPxM1 CCPxM0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 PxM1:PxM0: Enhanced PWM Output Configuration bits
If CCPxM3:CCPxM2 = 00, 01, 10:
xx = PxA assigned as Capture/Compare input/output; PxB, PxC, PxD assigned as port pins
If CCPxM3:CCPxM2 = 11:
00 = Single output: PxA modulated; PxB, PxC, PxD assigned as port pins
01 = Full-bridge output forward: P1D modulated; P1A active; P1B, P1C inactive
10 = Half-bridge output: P1A, P1B modulated with dead-band control; P1C, P1D assigned as port pins
11 = Full-bridge output reverse: P1B modulated; P1C active; P1A, P1D inactive
bit 5-4 DCxB1:DCxB0: PWM Duty Cycle bit 1 and bit 0
Capture mode:
Unused.
Compare mode:
Unused.
PWM mode:
These bits are the two LSbs of the 10-bit PWM duty cycle. The eight MSbs of the duty cycle are found in CCPRxL.
PIC18F87J11 FAMILY
DS39778C-page 204 Preliminary © 2008 Microchip Technology Inc.
18.1 ECCP Outputs and Configuration
Each of the Enhanced CCP modules may have up to
four PWM outputs, depending on the selected
operating mode. These outputs, designated PxA
through PxD, are multiplexed with various I/O pins.
Some ECCP pin assignments are constant, while
others change based on device configuration. For
those pins that do change, the controlling bits are:
CCP2MX Configuration bit
ECCPMX Configuration bit (80-pin devices only)
Program Memory Operating mode, set by the
EMB Configuration bits (80-pin devices only)
The pin assignments for the Enhanced CCP modules
are summarized in Table 18-1, Table 18-2 and
Table 18-3. To configure the I/O pins as PWM outputs,
the proper PWM mode must be selected by setting the
PxMx and CCPxMx bits (CCPxCON<7:6> and <3:0>,
respectively). The appropriate TRIS direction bits for
the corresponding port pins must also be set as
outputs.
18.1.1 ECCP1/ECCP3 OUTPUTS AND
PROGRAM MEMORY MODE
In 80-pin devices, the use of Extended Microcontroller
mode has an indirect effect on the use of ECCP1 and
ECCP3 in Enhanced PWM modes. By default, PWM
outputs, P1B/P1C and P3B/P3C, are multiplexed to
PORTE pins along with the high-order byte of the
external memory bus. When the bus is active in
Extended Microcontroller mode, it overrides the
Enhanced CCP outputs and makes them unavailable.
Because of this, ECCP1 and ECCP3 can only be used
in compatible (single output) PWM modes when the
device is in Extended Microcontroller mode and default
pin configuration.
An exception to this configuration is when a 12-bit
address width is selected for the external bus
(EMB1:EMB0 Configuration bits = 01). In this case, the
upper pins of PORTE continue to operate as digital I/O,
even when the external bus is active. P1B/P1C and
P3B/P3C remain available for use as Enhanced PWM
outputs.
If an application requires the use of additional PWM
outputs during enhanced microcontroller operation, the
P1B/P1C and P3B/P3C outputs can be reassigned to
the upper bits of PORTH. This is done by clearing the
ECCPMX Configuration bit.
18.1.2 ECCP2 OUTPUTS AND PROGRAM
MEMORY MODES
For 80-pin devices, the program memory mode of the
device (Section 5.1.3 “PIC18F8xJ11/8XJ16 Program
Memory Modes”) also impacts pin multiplexing for the
module.
The ECCP2 input/output (ECCP2/P2A) can be
multiplexed to one of three pins. The default
assignment (CCP2MX Configuration bit is set) for all
devices is RC1. Clearing CCP2MX reassigns ECCP2/
P2A to RE7.
An additional option exists for 80-pin devices. When
these devices are operating in Microcontroller mode,
the multiplexing options described above still apply. In
Extended Microcontroller mode, clearing CCP2MX
reassigns ECCP2/P2A to RB3.
Changing the pin assignment of ECCP2 does not
automatically change any requirements for configuring
the port pin. Users must always verify that the
appropriate TRIS register is configured correctly for
ECCP2 operation regardless of where it is located.
bit 3-0 CCPxM3:CCPxM0: Enhanced CCPx Module Mode Select bits
0000 = Capture/Compare/PWM off (resets ECCPx module)
0001 = Reserved
0010 = Compare mode, toggle output on match
0011 = Capture mode
0100 = Capture mode: every falling edge
0101 = Capture mode: every rising edge
0110 = Capture mode: every 4th rising edge
0111 = Capture mode: every 16th rising edge
1000 = Compare mode: initialize ECCPx pin low; set output on compare match (set CCPxIF)
1001 = Compare mode: initialize ECCPx pin high; clear output on compare match (set CCPxIF)
1010 = Compare mode: generate software interrupt only; ECCPx pin reverts to I/O state
1011 = Compare mode: trigger special event (ECCPx resets TMR1 or TMR3, sets CCPxIF bit,
ECCPx trigger also starts A/D conversion if A/D module is enabled)(1)
1100 = PWM mode: PxA, PxC active-high; PxB, PxD active-high
1101 = PWM mode: PxA, PxC active-high; PxB, PxD active-low
1110 = PWM mode: PxA, PxC active-low; PxB, PxD active-high
1111 = PWM mode: PxA, PxC active-low; PxB, PxD active-low
Note 1: Implemented only for ECCP1 and ECCP2; same as ‘1010’ for ECCP3.
REGISTER 18-1: CCPxCON: ECCPx CONTROL REGISTER (ECCP1/ECCP2/ECCP3)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 205
PIC18F87J11 FAMILY
18.1.3 USE OF CCP4 AND CCP5 WITH
ECCP1 AND ECCP3
Only the ECCP2 module has four dedicated output pins
that are available for use. Assuming that the I/O ports
or other multiplexed functions on those pins are not
needed, they may be used whenever needed without
interfering with any other CCP module.
ECCP1 and ECCP3, on the other hand, only have
three dedicated output pins: ECCPx/PxA, PxB and
PxC. Whenever these modules are configured for
Quad PWM mode, the pin normally used for CCP4 or
CCP5 becomes the PxD output pins for ECCP3 and
ECCP1, respectively. The CCP4 and CCP5 modules
remain functional but their outputs are overridden.
18.1.4 ECCP MODULES AND TIMER
RESOURCES
Like the standard CCP modules, the ECCP modules
can utilize Timers 1, 2, 3 or 4, depending on the mode
selected. Timer1 and Timer3 are available for modules
in Capture or Compare modes, while Timer2 and
Timer4 are available for modules in PWM mode.
Additional details on timer resources are provided in
Section 17.1.1 “CCP Modules and Timer
Resources”.
18.1.5 OPEN-DRAIN OUTPUT OPTION
When operating in compare or standard PWM modes,
the drivers for the ECCP pins can be optionally
configured as open-drain outputs. This feature allows
the voltage level on the pin to be pulled to a higher level
through an external pull-up resistor, and allows the
output to communicate with external circuits without the
need for additional level shifters. For more information,
see Section 10.1.4 “Open-Drain Outputs”
The open-drain output option is controlled by the bits in
the ODCON1 register. Setting the appropriate bit
configures the pin for the corresponding module for
open-drain operation. The ODCON1 memory shares
the same address space as of TMR1H. The ODCON1
register can be accessed by setting the ADSHR bit in
the WDTCON register (WDTCON<4>).
TABLE 18-1: PIN CONFIGURATIONS FOR ECCP1
ECCP Mode CCP1CON
Configuration RC2 RE6 RE5 RG4 RH7 RH6
All PIC18F6XJ1X Devices:
Compatible CCP 00xx 11xx ECCP1 RE6 RE5 RG4/CCP5 N/A N/A
Dual PWM 10xx 11xx P1A P1B RE5 RG4/CCP5 N/A N/A
Quad PWM(1) x1xx 11xx P1A P1B P1C P1D N/A N/A
PIC18F8XJ1X Devices, ECCPMX = 0, Microcontroller mode:
Compatible CCP 00xx 11xx ECCP1 RE6/AD14 RE5/AD13 RG4/CCP5 RH7/AN15 RH6/AN14
Dual PWM 10xx 11xx P1A RE6/AD14 RE5/AD13 RG4/CCP5 P1B RH6/AN14
Quad PWM(1) x1xx 11xx P1A RE6/AD14 RE5/AD13 P1D P1B P1C
PIC18F8XJ1X Devices, ECCPMX = 1, Extended Microcontroller mode, 16-Bit or 20-Bit Address Width:
Compatible CCP 00xx 11xx ECCP1 RE6/AD14 RE5/AD13 RG4/CCP5 RH7/AN15 RH6/AN14
PIC18F8XJ1X Devices, ECCPMX = 1,
Microcontroller mode or Extended Microcontroller mode, 12-Bit Address Width:
Compatible CCP 00xx 11xx ECCP1 RE6/AD14 RE5/AD13 RG4/CCP5 RH7/AN15 RH6/AN14
Dual PWM 10xx 11xx P1A P1B RE5/AD13 RG4/CCP5 RH7/AN15 RH6/AN14
Quad PWM(1) x1xx 11xx P1A P1B P1C P1D RH7/AN15 RH6/AN14
Legend: x = Don’t care, N/A = Not Available. Shaded cells indicate pin assignments not used by ECCP1 in a given mode.
Note 1: With ECCP1 in Quad PWM mode, CCP5’s output is overridden by P1D; otherwise, CCP5 is fully operational.
PIC18F87J11 FAMILY
DS39778C-page 206 Preliminary © 2008 Microchip Technology Inc.
TABLE 18-2: PIN CONFIGURATIONS FOR ECCP2
TABLE 18-3: PIN CONFIGURATIONS FOR ECCP3
ECCP Mode CCP2CON
Configuration RB3 RC1 RE7 RE2 RE1 RE0
All Devices, CCP2MX = 1, Either Operating mode:
Compatible CCP 00xx 11xx RB3/INT3 ECCP2 RE7 RE2 RE1 RE0
Dual PWM 10xx 11xx RB3/INT3 P2A RE7 P2B RE1 RE0
Quad PWM x1xx 11xx RB3/INT3 P2A RE7 P2B P2C P2D
All Devices, CCP2MX = 0, Microcontroller mode:
Compatible CCP 00xx 11xx RB3/INT3 RC1/T1OS1 ECCP2 RE2 RE1 RE0
Dual PWM 10xx 11xx RB3/INT3 RC1/T1OS1 P2A P2B RE1 RE0
Quad PWM x1xx 11xx RB3/INT3 RC1/T1OS1 P2A P2B P2C P2D
PIC18F8XJ1X Devices, CCP2MX = 0, Extended Microcontroller mode:
Compatible CCP 00xx 11xx ECCP2 RC1/T1OS1 RE7/AD15 RE2/CS RE1/WR RE0/RD
Dual PWM 10xx 11xx P2A RC1/T1OS1 RE7/AD15 P2B RE1/WR RE0/RD
Quad PWM x1xx 11xx P2A RC1/T1OS1 RE7/AD15 P2B P2C P2D
Legend: x = Don’t care. Shaded cells indicate pin assignments not used by ECCP2 in a given mode.
ECCP Mode CCP3CON
Configuration RG0 RE4 RE3 RG3 RH5 RH4
PIC18F6XJ1X Devices:
Compatible CCP 00xx 11xx ECCP3 RE4 RE3 RG3/CCP4 N/A N/A
Dual PWM 10xx 11xx P3A P3B RE3 RG3/CCP4 N/A N/A
Quad PWM(1) x1xx 11xx P3A P3B P3C P3D N/A N/A
PIC18F8XJ1X Devices, ECCPMX = 0, Microcontroller mode:
Compatible CCP 00xx 11xx ECCP3 RE6/AD14 RE5/AD13 RG3/CCP4 RH7/AN15 RH6/AN14
Dual PWM 10xx 11xx P3A RE6/AD14 RE5/AD13 RG3/CCP4 P3B RH6/AN14
Quad PWM(1) x1xx 11xx P3A RE6/AD14 RE5/AD13 P3D P3B P3C
PIC18F8XJ1X Devices, ECCPMX = 1, Extended Microcontroller mode, 16-Bit or 20-Bit Address Width:
Compatible CCP 00xx 11xx ECCP3 RE6/AD14 RE5/AD13 RG3/CCP4 RH7/AN15 RH6/AN14
PIC18F8XJ1X Devices, ECCPMX = 1,
Microcontroller mode or Extended Microcontroller mode, 12-Bit Address Width:
Compatible CCP 00xx 11xx ECCP3 RE4/AD12 RE3/AD11 RG3/CCP4 RH5/AN13 RH4/AN12
Dual PWM 10xx 11xx P3A P3B RE3/AD11 RG3/CCP4 RH5/AN13 RH4/AN12
Quad PWM(1) x1xx 11xx P3A P3B P3C P3D RH5/AN13 RH4/AN12
Legend: x = Don’t care, N/A = Not Available. Shaded cells indicate pin assignments not used by ECCP3 in a given mode.
Note 1: With ECCP3 in Quad PWM mode, CCP4’s output is overridden by P1D; otherwise, CCP4 is fully operational.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 207
PIC18F87J11 FAMILY
18.2 Capture and Compare Modes
Except for the operation of the Special Event Trigger
discussed below, the Capture and Compare modes of
the ECCP module are identical in operation to that of
CCP4. These are discussed in detail in Section 17.2
“Capture Mode” and Section 17.3 “Compare
Mode”.
18.2.1 SPECIAL EVENT TRIGGER
ECCP1 and ECCP2 incorporate an internal hardware
trigger that is generated in Compare mode on a match
between the CCPRx register pair and the selected
timer. This can be used in turn to initiate an action. This
mode is selected by setting CCPxCON<3:0> to ‘1011’.
The Special Event Trigger output of either ECCP1 or
ECCP2 resets the TMR1 or TMR3 register pair, depend-
ing on which timer resource is currently selected. This
allows the CCPRx register pair to effectively be a 16-bit
programmable period register for Timer1 or Timer3. In
addition, the ECCP2 Special Event Trigger will also start
an A/D conversion if the A/D module is enabled.
Special Event Triggers are not implemented for
ECCP3, CCP4 or CCP5. Selecting the Special Event
Trigger mode for these modules has the same effect as
selecting the Compare with Software Interrupt mode
(CCPxM3:CCPxM0 = 1010).
18.3 Standard PWM Mode
When configured in Single Output mode, the ECCP
module functions identically to the standard CCP
module in PWM mode, as described in Section 17.4
“PWM Mode”. This is also sometimes referred to as
“Compatible CCP” mode as in Tables 18-1
through 18-3.
Note: The Special Event Trigger from ECCP2
will not set the Timer1 or Timer3 interrupt
flag bits.
Note: When setting up single output PWM
operations, users are free to use either of
the processes described in Section 17.4.3
“Setup for PWM Operation” or
Section 18.4.9 “Setup for PWM Opera-
tion”. The latter is more generic but will
work for either single or multi-output PWM.
PIC18F87J11 FAMILY
DS39778C-page 208 Preliminary © 2008 Microchip Technology Inc.
18.4 Enhanced PWM Mode
The Enhanced PWM mode provides additional PWM
output options for a broader range of control applica-
tions. The module is a backward compatible version of
the standard CCP module and offers up to four outputs,
designated PxA through PxD. Users are also able to
select the polarity of the signal (either active-high or
active-low). The module’s output mode and polarity
are configured by setting the PxM1:PxM0 and
CCPxM3:CCPxM0 bits of the CCPxCON register
(CCPxCON<7:6> and CCPxCON<3:0>, respectively).
For the sake of clarity, Enhanced PWM mode operation
is described generically throughout this section with
respect to the ECCP1 and TMR2 modules. Control reg-
ister names are presented in terms of ECCP1. All three
Enhanced modules, as well as the two timer resources,
can be used interchangeably and function identically.
TMR2 or TMR4 can be selected for PWM operation by
selecting the proper bits in T3CON.
Figure 18-1 shows a simplified block diagram of PWM
operation. All control registers are double-buffered and
are loaded at the beginning of a new PWM cycle (the
period boundary when Timer2 resets) in order to
prevent glitches on any of the outputs. The exception is
the ECCPx PWM Delay register, ECCPxDEL, which is
loaded at either the duty cycle boundary or the bound-
ary period (whichever comes first). Because of the
buffering, the module waits until the assigned timer
resets instead of starting immediately. This means that
Enhanced PWM waveforms do not exactly match the
standard PWM waveforms, but are instead offset by
one full instruction cycle (4 TOSC).
As before, the user must manually configure the
appropriate TRIS bits for output.
18.4.1 PWM PERIOD
The PWM period is specified by writing to the PR2
register. The PWM period can be calculated using the
equation:
EQUATION 18-1:
PWM frequency is defined as 1/[PWM period]. When
TMR2 is equal to PR2, the following three events occur
on the next increment cycle:
•TMR2 is cleared
The ECCP1 pin is set (if PWM duty cycle = 0%,
the ECCP1 pin will not be set)
The PWM duty cycle is copied from CCPR1L into
CCPR1H
FIGURE 18-1: SIMPLIFIED BLOCK DIAGRAM OF THE ENHANCED PWM MODULE
Note: The Timer2 postscaler (see Section 14.0
“Timer2 Module”) is not used in the
determination of the PWM frequency. The
postscaler could be used to have a servo
update rate at a different frequency than
the PWM output.
PWM Period = [(PR2) + 1] • 4 • TOSC
(TMR2 Prescale Value)
CCPR1L
CCPR1H (Slave)
Comparator
TMR2
Comparator
PR2
(Note 1)
RQ
S
Duty Cycle Registers CCP1CON<5:4>
Clear Timer,
set ECCP1 pin and
latch D.C.
Note: The 8-bit TMR2 register is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler, to create the 10-bit time base.
TRISx<x>
ECCP1/P1A
TRISx<x>
P1B
TRISx<x>
TRISx<x>
P1D
Output
Controller
P1M1<1:0>
2
CCP1M<3:0>
4
ECCP1DEL
ECCP1/P1A
P1B
P1C
P1D
P1C
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 209
PIC18F87J11 FAMILY
18.4.2 PWM DUTY CYCLE
The PWM duty cycle is specified by writing to the
CCPR1L register and to the CCP1CON<5:4> bits. Up
to 10-bit resolution is available. The CCPR1L contains
the eight MSbs and the CCP1CON<5:4> contains the
two LSbs. This 10-bit value is represented by
CCPR1L:CCP1CON<5:4>. The PWM duty cycle is
calculated by the following equation:
EQUATION 18-2:
CCPR1L and CCP1CON<5:4> can be written to at any
time but the duty cycle value is not copied into
CCPR1H until a match between PR2 and TMR2 occurs
(i.e., the period is complete). In PWM mode, CCPR1H
is a read-only register.
The CCPR1H register and a 2-bit internal latch are
used to double-buffer the PWM duty cycle. This
double-buffering is essential for glitchless PWM opera-
tion. When the CCPR1H and 2-bit latch match TMR2,
concatenated with an internal 2-bit Q clock or two bits
of the TMR2 prescaler, the ECCP1 pin is cleared. The
maximum PWM resolution (bits) for a given PWM
frequency is given by the equation:
EQUATION 18-3:
18.4.3 PWM OUTPUT CONFIGURATIONS
The P1M1:P1M0 bits in the CCP1CON register allow
one of four configurations:
Single Output
Half-Bridge Output
Full-Bridge Output, Forward mode
Full-Bridge Output, Reverse mode
The Single Output mode is the standard PWM mode
discussed in Section 18.4 “Enhanced PWM Mode”.
The Half-Bridge and Full-Bridge Output modes are
covered in detail in the sections that follow.
The general relationship of the outputs in all
configurations is summarized in Figure 18-2.
TABLE 18-4: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz
PWM Duty Cycle = (CCPR1L:CCP1CON<5:4>) •
TOSC • (TMR2 Prescale Value)
( )
PWM Resolution (max) =
FOSC
FPWM
log
log(2) bits
Note: If the PWM duty cycle value is longer than
the PWM period, the ECCP1 pin will not
be cleared.
PWM Frequency 2.44 kHz 9.77 kHz 39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz
Timer Prescaler (1, 4, 16)1641111
PR2 Value FFh FFh FFh 3Fh 1Fh 17h
Maximum Resolution (bits) 10 10 10 8 7 6.58
PIC18F87J11 FAMILY
DS39778C-page 210 Preliminary © 2008 Microchip Technology Inc.
FIGURE 18-2: PWM OUTPUT RELATIONSHIPS (ACTIVE-HIGH STATE)
FIGURE 18-3: PWM OUTPUT RELATIONSHIPS (ACTIVE-LOW STATE)
0
Period
00
10
01
11
SIGNAL
PR2 + 1
CCP1CON<7:6>
P1A Modulated
P1A Modulated
P1B Modulated
P1A Active
P1B Inactive
P1C Inactive
P1D Modulated
P1A Inactive
P1B Modulated
P1C Active
P1D Inactive
Duty
Cycle
(Single Output)
(Half-Bridge)
(Full-Bridge,
Forward)
(Full-Bridge,
Reverse)
Delay(1) Delay(1)
0
Period
00
10
01
11
SIGNAL PR2 + 1
CCP1CON<7:6> Duty
Cycle
(Single Output)
(Half-Bridge)
(Full-Bridge,
Forward)
(Full-Bridge,
Reverse)
Delay(1) Delay(1)
Relationships:
Period = 4 * TOSC * (PR2 + 1) * (TMR2 Prescale Value)
Duty Cycle = T
OSC * (CCPR1L<7:0>:CCP1CON<5:4>) * (TMR2 Prescale Value)
Delay = 4 * T
OSC * (ECCP1DEL<6:0>)
Note 1: Dead-band delay is programmed using the ECCP1DEL register (Section 18.4.6 “Programmable
Dead-Band Delay”).
P1A Modulated
P1A Modulated
P1B Modulated
P1A Active
P1B Inactive
P1C Inactive
P1D Modulated
P1A Inactive
P1B Modulated
P1C Active
P1D Inactive
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 211
PIC18F87J11 FAMILY
18.4.4 HALF-BRIDGE MODE
In the Half-Bridge Output mode, two pins are used as
outputs to drive push-pull loads. The PWM output
signal is output on the P1A pin, while the complemen-
tary PWM output signal is output on the P1B pin
(Figure 18-4). This mode can be used for half-bridge
applications, as shown in Figure 18-5, or for full-bridge
applications, where four power switches are being
modulated with two PWM signals.
In Half-Bridge Output mode, the programmable
dead-band delay can be used to prevent shoot-through
current in half-bridge power devices. The value of bits
P1DC6:P1DC0 sets the number of instruction cycles
before the output is driven active. If the value is greater
than the duty cycle, the corresponding output remains
inactive during the entire cycle. See Section 18.4.6
“Programmable Dead-Band Delay” for more details
on dead-band delay operations.
Since the P1A and P1B outputs are multiplexed with
the PORTC<2> and PORTE<6> data latches, the
TRISC<2> and TRISE<6> bits must be cleared to
configure P1A and P1B as outputs.
FIGURE 18-4: HALF-BRIDGE PWM
OUTPUT
FIGURE 18-5: EXAMPLES OF HALF-BRIDGE OUTPUT MODE APPLICATIONS
Period
Duty Cycle
td
td
(1)
P1A(2)
P1B(2)
td = Dead Band Delay
Period
(1) (1)
Note 1: At this time, the TMR2 register is equal to the
PR2 register.
2: Output signals are shown as active-high.
PIC18F87J11
P1A
P1B
FET
Driver
FET
Driver
V+
V-
Load
+
V
-
+
V
-
FET
Driver
FET
Driver
V+
V-
Load
FET
Driver
FET
Driver
PIC18F87J11
P1A
P1B
Standard Half-Bridge Circuit (“Push-Pull”)
Half-Bridge Output Driving a Full-Bridge Circuit
PIC18F87J11 FAMILY
DS39778C-page 212 Preliminary © 2008 Microchip Technology Inc.
18.4.5 FULL-BRIDGE MODE
In Full-Bridge Output mode, four pins are used as
outputs; however, only two outputs are active at a time.
In the Forward mode, pin P1A is continuously active
and pin P1D is modulated. In the Reverse mode, pin
P1C is continuously active and pin P1B is modulated.
These are illustrated in Figure 18-6.
P1A, P1B, P1C and P1D outputs are multiplexed with
the port pins as described in Table 18-1, Table 18-2
and Table 18-3. The corresponding TRIS bits must be
cleared to make the P1A, P1B, P1C and P1D pins
outputs.
FIGURE 18-6: FULL-BRIDGE PWM OUTPUT
Period
Duty Cycle
P1A(2)
P1B(2)
P1C(2)
P1D(2)
Forward Mode
(1)
Period
Duty Cycle
P1A(2)
P1C(2)
P1D(2)
P1B(2)
Reverse Mode
(1)
(1)
(1)
Note 1: At this time, the TMR2 register is equal to the PR2 register.
Note 2: Output signal is shown as active-high.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 213
PIC18F87J11 FAMILY
FIGURE 18-7: EXAMPLE OF FULL-BRIDGE OUTPUT APPLICATION
18.4.5.1 Direction Change in Full-Bridge
Output Mode
In the Full-Bridge Output mode, the P1M1 bit in the
CCP1CON register allows users to control the forward/
reverse direction. When the application firmware
changes this direction control bit, the module will
assume the new direction on the next PWM cycle.
Just before the end of the current PWM period, the
modulated outputs (P1B and P1D) are placed in their
inactive state, while the unmodulated outputs (P1A and
P1C) are switched to drive in the opposite direction.
This occurs in a time interval of (4 TOSC * (Timer2
Prescale Value) before the next PWM period begins.
The Timer2 prescaler will be either 1, 4 or 16, depend-
ing on the value of the T2CKPS bits (T2CON<1:0>).
During the interval from the switch of the unmodulated
outputs to the beginning of the next period, the
modulated outputs (P1B and P1D) remain inactive.
This relationship is shown in Figure 18-8.
Note that in the Full-Bridge Output mode, the ECCP1
module does not provide any dead-band delay. In gen-
eral, since only one output is modulated at all times,
dead-band delay is not required. However, there is a
situation where a dead-band delay might be required.
This situation occurs when both of the following
conditions are true:
1. The direction of the PWM output changes when
the duty cycle of the output is at or near 100%.
2. The turn-off time of the power switch, including
the power device and driver circuit, is greater
than the turn-on time.
Figure 18-9 shows an example where the PWM direc-
tion changes from forward to reverse at a near 100%
duty cycle. At time t1, the outputs, P1A and P1D,
become inactive, while output, P1C, becomes active. In
this example, since the turn-off time of the power
devices is longer than the turn-on time, a shoot-through
current may flow through power devices, QC and QD
(see Figure 18-7), for the duration of ‘t’. The same
phenomenon will occur to power devices, QA and QB,
for PWM direction change from reverse to forward.
If changing PWM direction at high duty cycle is required
for an application, one of the following requirements
must be met:
1. Reduce PWM for a PWM period before
changing directions.
2. Use switch drivers that can drive the switches off
faster than they can drive them on.
Other options to prevent shoot-through current may
exist.
PIC18F87J11
P1A
P1C
FET
Driver
FET
Driver
V+
V-
Load
FET
Driver
FET
Driver
P1B
P1D
QA
QB QD
QC
PIC18F87J11 FAMILY
DS39778C-page 214 Preliminary © 2008 Microchip Technology Inc.
FIGURE 18-8: PWM DIRECTION CHANGE
FIGURE 18-9: PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE
DC
Period(1)
SIGNAL
Note 1: The direction bit in the ECCP1 Control register (CCP1CON<7>) is written at any time during the PWM cycle.
2: When changing directions, the P1A and P1C signals switch before the end of the current PWM cycle at intervals
of 4 TOSC, 16 TOSC or 64 TOSC, depending on the Timer2 prescaler value. The modulated P1B and P1D signals
are inactive at this time.
Period
(Note 2)
P1A (Active-High)
P1B (Active-High)
P1C (Active-High)
P1D (Active-High)
DC
Forward Period Reverse Period
P1A(1)
tON(2)
tOFF(3)
t = tOFF – tON(2,3)
P1B(1)
P1C(1)
P1D(1)
External Switch D(1)
Potential
Shoot-Through
Current(1)
Note 1: All signals are shown as active-high.
2: tON is the turn-on delay of power switch QC and its driver.
3: tOFF is the turn-off delay of power switch QD and its driver.
External Switch C(1)
t1
DC
DC
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 215
PIC18F87J11 FAMILY
18.4.6 PROGRAMMABLE DEAD-BAND
DELAY
In half-bridge applications, where all power switches
are modulated at the PWM frequency at all times, the
power switches normally require more time to turn off
than to turn on. If both the upper and lower power
switches are switched at the same time (one turned on
and the other turned off), both switches may be on for
a short period of time until one switch completely turns
off. During this brief interval, a very high current
(shoot-through current) may flow through both power
switches, shorting the bridge supply. To avoid this
potentially destructive shoot-through current from flow-
ing during switching, turning on either of the power
switches is normally delayed to allow the other switch
to completely turn off.
In the Half-Bridge Output mode, a digitally program-
mable, dead-band delay is available to avoid
shoot-through current from destroying the bridge
power switches. The delay occurs at the signal
transition from the non-active state to the active state
(see Figure 18-4 for illustration). The lower seven bits of
the ECCPxDEL register (Register 18-2) set the delay
period in terms of microcontroller instruction cycles
(T
CY or 4 TOSC).
18.4.7 ENHANCED PWM
AUTO-SHUTDOWN
When the ECCP1 is programmed for any of the
Enhanced PWM modes, the active output pins may be
configured for auto-shutdown. Auto-shutdown immedi-
ately places the Enhanced PWM output pins into a
defined shutdown state when a shutdown event
occurs.
A shutdown event can be caused by either of the two
comparator modules or the FLT0 pin (or any combina-
tion of these three sources). The comparators may be
used to monitor a voltage input proportional to a current
being monitored in the bridge circuit. If the voltage
exceeds a threshold, the comparator switches state and
triggers a shutdown. Alternatively, a low-level digital sig-
nal on the FLT0 pin can also trigger a shutdown. The
auto-shutdown feature can be disabled by not selecting
any auto-shutdown sources. The auto-shutdown
sources to be used are selected using the
ECCP1AS2:ECCP1AS0 bits (ECCP1AS<6:4>).
When a shutdown occurs, the output pins are
asynchronously placed in their shutdown states,
specified by the PSS1AC1:PSS1AC0 and
PSS1BD1:PSS1BD0 bits (ECCP1AS3:ECCP1AS0).
Each pin pair (P1A/P1C and P1B/P1D) may be set to
drive high, drive low or be tri-stated (not driving). The
ECCP1ASE bit (ECCP1AS<7>) is also set to hold the
Enhanced PWM outputs in their shutdown states.
The ECCP1ASE bit is set by hardware when a
shutdown event occurs. If automatic restarts are not
enabled, the ECCP1ASE bit is cleared by firmware
when the cause of the shutdown clears. If automatic
restarts are enabled, the ECCP1ASE bit is automati-
cally cleared when the cause of the auto-shutdown has
cleared.
If the ECCP1ASE bit is set when a PWM period begins,
the PWM outputs remain in their shutdown state for that
entire PWM period. When the ECCP1ASE bit is
cleared, the PWM outputs will return to normal
operation at the beginning of the next PWM period.
Note: Writing to the ECCP1ASE bit is disabled
while a shutdown condition is active.
PIC18F87J11 FAMILY
DS39778C-page 216 Preliminary © 2008 Microchip Technology Inc.
REGISTER 18-2: ECCPxDEL: ECCPx PWM DELAY REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PxRSEN PxDC6 PxDC5 PxDC4 PxDC3 PxDC2 PxDC1 PxDC0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 PxRSEN: PWM Restart Enable bit
1 = Upon auto-shutdown, the ECCPxASE bit clears automatically once the shutdown event goes
away; the PWM restarts automatically
0 = Upon auto-shutdown, ECCPxASE must be cleared in software to restart the PWM
bit 6-0 PxDC6:PxDC0: PWM Delay Count bits
Delay time, in number of FOSC/4 (4 * TOSC) cycles, between the scheduled and actual time for a PWM
signal to transition to active.
REGISTER 18-3: ECCPxAS: ECCPx AUTO-SHUTDOWN CONTROL REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ECCPxASE ECCPxAS2 ECCPxAS1 ECCPxAS0 PSSxAC1 PSSxAC0 PSSxBD1 PSSxBD0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 ECCPxASE: ECCPx Auto-Shutdown Event Status bit
0 = ECCPx outputs are operating
1 = A shutdown event has occurred; ECCPx outputs are in shutdown state
bit 6-4 ECCPxAS2:ECCPxAS0: ECCPx Auto-Shutdown Source Select bits
000 = Auto-shutdown is disabled
001 = Comparator 1 output
010 = Comparator 2 output
011 = Either Comparator 1 or 2
100 =FLT0
101 = FLT0 or Comparator 1
110 = FLT0 or Comparator 2
111 = FLT0 or Comparator 1 or Comparator 2
bit 3-2 PSSxAC1:PSSxAC0: Pins A and C Shutdown State Control bits
00 = Drive Pins A and C to 0
01 = Drive Pins A and C to 1
1x = Pins A and C tri-state
bit 1-0 PSSxBD1:PSSxBD0: Pins B and D Shutdown State Control bits
00 = Drive Pins B and D to 0
01 = Drive Pins B and D to 1
1x = Pins B and D tri-state
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 217
PIC18F87J11 FAMILY
18.4.7.1 Auto-Shutdown and Automatic
Restart
The auto-shutdown feature can be configured to allow
automatic restarts of the module following a shutdown
event. This is enabled by setting the P1RSEN bit of the
ECCP1DEL register (ECCP1DEL<7>).
In Shutdown mode with P1RSEN = 1 (Figure 18-10),
the ECCP1ASE bit will remain set for as long as the
cause of the shutdown continues. When the shutdown
condition clears, the ECCP1ASE bit is cleared. If
P1RSEN = 0 (Figure 18-11), once a shutdown condi-
tion occurs, the ECCP1ASE bit will remain set until it is
cleared by firmware. Once ECCP1ASE is cleared, the
Enhanced PWM will resume at the beginning of the
next PWM period.
Independent of the P1RSEN bit setting, if the
auto-shutdown source is one of the comparators, the
shutdown condition is a level. The ECCP1ASE bit
cannot be cleared as long as the cause of the shutdown
persists.
The Auto-Shutdown mode can be forced by writing a ‘1
to the ECCP1ASE bit.
18.4.8 START-UP CONSIDERATIONS
When the ECCP1 module is used in the PWM mode,
the application hardware must use the proper external
pull-up and/or pull-down resistors on the PWM output
pins. When the microcontroller is released from Reset,
all of the I/O pins are in the high-impedance state. The
external circuits must keep the power switch devices in
the OFF state until the microcontroller drives the I/O
pins with the proper signal levels, or activates the PWM
output(s).
The CCP1M1:CCP1M0 bits (CCP1CON<1:0>) allow
the user to choose whether the PWM output signals are
active-high or active-low for each pair of PWM output
pins (P1A/P1C and P1B/P1D). The PWM output
polarities must be selected before the PWM pins are
configured as outputs. Changing the polarity configura-
tion while the PWM pins are configured as outputs is
not recommended since it may result in damage to the
application circuits.
The P1A, P1B, P1C and P1D output latches may not be
in the proper states when the PWM module is initialized.
Enabling the PWM pins for output at the same time as
the ECCP1 module may cause damage to the applica-
tion circuit. The ECCP1 module must be enabled in the
proper output mode and complete a full PWM cycle
before configuring the PWM pins as outputs. The
completion of a full PWM cycle is indicated by the
TMR2IF bit being set as the second PWM period
begins.
FIGURE 18-10: PWM AUTO-SHUTDOWN (P1RSEN = 1, AUTO-RESTART ENABLED)
FIGURE 18-11: PWM AUTO-SHUTDOWN (P1RSEN = 0, AUTO-RESTART DISABLED)
Note: Writing to the ECCP1ASE bit is disabled
while a shutdown condition is active.
Shutdown
PWM
ECCP1ASE bit
Activity
Event
Shutdown
Event Occurs
Shutdown
Event Clears
PWM
Resumes
Normal PWM
Start of
PWM Period
PWM Period
Shutdown
PWM
ECCP1ASE bit
Activity
Event
Shutdown
Event Occurs
Shutdown
Event Clears
PWM
Resumes
Normal PWM
Start of
PWM Period
ECCP1ASE
Cleared by
Firmware
PWM Period
PIC18F87J11 FAMILY
DS39778C-page 218 Preliminary © 2008 Microchip Technology Inc.
18.4.9 SETUP FOR PWM OPERATION
The following steps should be taken when configuring
the ECCP module for PWM operation:
1. Configure the PWM pins PxA and PxB (and PxC
and PxD, if used) as inputs by setting the
corresponding TRIS bits.
2. Set the PWM period by loading the PR2 (PR4)
register.
3. Configure the ECCP module for the desired
PWM mode and configuration by loading the
CCPxCON register with the appropriate values:
Select one of the available output
configurations and direction with the
PxM1:PxM0 bits.
Select the polarities of the PWM output
signals with the CCPxM3:CCPxM0 bits.
4. Set the PWM duty cycle by loading the CCPRxL
register and the CCPxCON<5:4> bits.
5. For auto-shutdown:
Disable auto-shutdown; ECCPxASE = 0
Configure auto-shutdown source
Wait for Run condition
6. For Half-Bridge Output mode, set the
dead-band delay by loading ECCPxDEL<6:0>
with the appropriate value.
7. If auto-shutdown operation is required, load the
ECCPxAS register:
Select the auto-shutdown sources using the
ECCPxAS2:ECCPxAS0 bits.
Select the shutdown states of the PWM
output pins using the PSSxAC1:PSSxAC0
and PSSxBD1:PSSxBD0 bits.
Set the ECCPxASE bit (ECCPxAS<7>).
8. If auto-restart operation is required, set the
PxRSEN bit (ECCPxDEL<7>).
9. Configure and start TMRn (TMR2 or TMR4):
Clear the TMRn interrupt flag bit by clearing
the TMRnIF bit (PIR1<1> for Timer2 or
PIR3<3> for Timer4).
Set the TMRn prescale value by loading the
TnCKPS bits (TnCON<1:0>).
Enable Timer2 (or Timer4) by setting the
TMRnON bit (TnCON<2>).
10. Enable PWM outputs after a new PWM cycle
has started:
Wait until TMRn overflows (TMRnIF bit is set).
Enable the ECCPx/PxA, PxB, PxC and/or
PxD pin outputs by clearing the respective
TRIS bits.
Clear the ECCPxASE bit (ECCPxAS<7>).
18.4.10 EFFECTS OF A RESET
Both Power-on Reset and subsequent Resets will force
all ports to Input mode and the ECCP registers to their
Reset states.
This forces the Enhanced CCP module to reset to a
state compatible with the standard CCP module.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 219
PIC18F87J11 FAMILY
TABLE 18-5: REGISTERS ASSOCIATED WITH ECCP MODULES AND TIMER1 TO TIMER4
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
RCON IPEN CM RI TO PD POR BOR 56
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR2 OSCFIF CM2IF CM1IF BCL1IF LVDIF TMR3IF CCP2IF 58
PIE2 OSCFIE CM2IE CM1IE BCL1IE LVDIE TMR3IE CCP2IE 58
IPR2 OSCFIP CM2IP CM1IP BCL1IP LVDIP TMR3IP CCP2IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
TRISB TRISB7 TRISB6 TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 58
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 58
TRISE TRISE7 TRISE6 TRISE5 TRISE4 TRISE3 TRISE2 TRISE1 TRISE0 58
TRISG TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 58
TRISH(1) TRISH7 TRISH6 TRISH5 TRISH4 TRISH3 TRISH2 TRISH1 TRISH0 58
TMR1L(3) Timer1 Register Low Byte 56
TMR1H(3) Timer1 Register High Byte 56
ODCON1(4) CCP5OD CCP4OD ECCP3OD ECCP2OD ECCP1OD 56
T1CON(3) RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 56
TMR2(3) Timer2 Register 56
T2CON T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 56
PR2(3) Timer2 Period Register 56
TMR3L Timer3 Register Low Byte 59
TMR3H Timer3 Register High Byte 59
T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON 59
TMR4 Timer4 Register 59
T4CON T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0 59
PR4(3) Timer4 Period Register 59
CCPRxL(2) Capture/Compare/PWM Register x Low Byte 57
CCPRxH(2) Capture/Compare/PWM Register x High Byte 57,
CCPxCON(2) PxM1 PxM0 DCxB1 DCxB0 CCPxM3 CCPxM2 CCPxM1 CCPxM0 57
ECCPxAS(2) ECCPxASE ECCPxAS2 ECCPxAS1 ECCPxAS0 PSSxAC1 PSSxAC0 PSSxBD1 PSSxBD0 57
ECCPxDEL(2) PxRSEN PxDC6 PxDC5 PxDC4 PxDC3 PxDC2 PxDC1 PxDC0 57
Legend: = unimplemented, read as0. Shaded cells are not used during ECCP operation.
Note 1: Available on 80-pin devices only.
2: Generic term for all of the identical registers of this name for all Enhanced CCP modules, where ‘x’ identifies the
individual module (ECCP1, ECCP2 or ECCP3). Bit assignments and Reset values for all registers of the same
generic name are identical.
3: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
4: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
PIC18F87J11 FAMILY
DS39778C-page 220 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 221
PIC18F87J11 FAMILY
19.0 MASTER SYNCHRONOUS
SERIAL PORT (MSSP)
MODULE
19.1 Master SSP (MSSP) Module
Overview
The Master Synchronous Serial Port (MSSP) module is
a serial interface, useful for communicating with other
peripheral or microcontroller devices. These peripheral
devices may be serial EEPROMs, shift registers,
display drivers, A/D converters, etc. The MSSP module
can operate in one of two modes:
Serial Peripheral Interface (SPI)
Inter-Integrated Circuit (I2C™)
- Full Master mode
- Slave mode (with general address call)
The I2C interface supports the following modes in
hardware:
•Master mode
Multi-Master mode
Slave mode with 5-bit and 7-bit address masking
(with address masking for both 10-bit and 7-bit
addressing)
All members of the PIC18F87J11 Family have two
MSSP modules, designated as MSSP1 and MSSP2.
Each module operates independently of the other.
19.2 Control Registers
Each MSSP module has three associated control regis-
ters. These include a status register (SSPxSTAT) and
two control registers (SSPxCON1 and SSPxCON2). The
use of these registers and their individual configuration
bits differ significantly depending on whether the MSSP
module is operated in SPI or I2C mode.
Additional details are provided under the individual
sections.
19.3 SPI Mode
The SPI mode allows 8 bits of data to be synchronously
transmitted and received simultaneously. All four
modes of SPI are supported. To accomplish
communication, typically three pins are used:
Serial Data Out (SDOx) – RC5/SDO1 or
RD4/SDO2
Serial Data In (SDIx) – RC4/SDI1/SDA1 or
RD5/SDI2/SDA2
Serial Clock (SCKx) – RC3/SCK1/SCL1 or
RD6/SCK2/SCL2
Additionally, a fourth pin may be used when in a Slave
mode of operation:
Slave Select (SSx) – RF7/SS1 or RD7/SS2
Figure 19-1 shows the block diagram of the MSSP
module when operating in SPI mode.
FIGURE 19-1: MSSP BLOCK DIAGRAM
(SPI MODE)
Note: Throughout this section, generic refer-
ences to an MSSP module in any of its
operating modes may be interpreted as
being equally applicable to MSSP1 or
MSSP2. Register names and module I/O
signals use the generic designator ‘x’ to
indicate the use of a numeral to distinguish
a particular module when required. Control
bit names are not individuated.
Note: In devices with more than one MSSP
module, it is very important to pay close
attention to SSPxCON register names.
SSP1CON1 and SSP1CON2 control
different operational aspects of the same
module, while SSP1CON1 and
SSP2CON1 control the same features for
two different modules.
( )
Read Write
Internal
Data Bus
SSPxSR reg
SSPM3:SSPM0
bit 0 Shift
Clock
SSxControl
Enable
Edge
Select
Clock Select
TMR2 Output
TOSC
Prescaler
4, 16, 64
2
Edge
Select
2
4
Data to TXx/RXx in SSPxSR
TRIS bit
2
SMP:CKE
SDOx
SSPxBUF reg
SDIx
SSx
SCKx
Note: Only port I/O names are used in this diagram for
the sake of brevity. Refer to the text for a full list of
multiplexed functions.
PIC18F87J11 FAMILY
DS39778C-page 222 Preliminary © 2008 Microchip Technology Inc.
19.3.1 REGISTERS
Each MSSP module has four registers for SPI mode
operation. These are:
MSSPx Control Register 1 (SSPxCON1)
MSSPx Status Register (SSPxSTAT)
Serial Receive/Transmit Buffer Register
(SSPxBUF)
MSSPx Shift Register (SSPxSR) – Not directly
accessible
SSPxCON1 and SSPxSTAT are the control and status
registers in SPI mode operation. The SSPxCON1
register is readable and writable. The lower 6 bits of
the SSPxSTAT are read-only. The upper two bits of the
SSPxSTAT are read/write.
SSPxSR is the shift register used for shifting data in or
out. SSPxBUF is the buffer register to which data
bytes are written to or read from.
In receive operations, SSPxSR and SSPxBUF
together create a double-buffered receiver. When
SSPxSR receives a complete byte, it is transferred to
SSPxBUF and the SSPxIF interrupt is set.
During transmission, the SSPxBUF is not
double-buffered. A write to SSPxBUF will write to both
SSPxBUF and SSPxSR.
REGISTER 19-1: SSPxSTAT: MSSPx STATUS REGISTER (SPI MODE)
R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0
SMP CKE(1) D/A PSR/WUA BF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SMP: Sample bit
SPI Master mode:
1 = Input data sampled at end of data output time
0 = Input data sampled at middle of data output time
SPI Slave mode:
SMP must be cleared when SPI is used in Slave mode.
bit 6 CKE: SPI Clock Select bit(1)
1 = Transmit occurs on transition from active to Idle clock state
0 = Transmit occurs on transition from Idle to active clock state
bit 5 D/A: Data/Address bit
Used in I2C mode only.
bit 4 P: Stop bit
Used in I2C mode only. This bit is cleared when the MSSPx module is disabled, SSPEN is cleared.
bit 3 S: Start bit
Used in I2C mode only.
bit 2 R/W: Read/Write Information bit
Used in I2C mode only.
bit 1 UA: Update Address bit
Used in I2C mode only.
bit 0 BF: Buffer Full Status bit (Receive mode only)
1 = Receive complete, SSPxBUF is full
0 = Receive not complete, SSPxBUF is empty
Note 1: Polarity of clock state is set by the CKP bit (SSPxCON1<4>).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 223
PIC18F87J11 FAMILY
REGISTER 19-2: SSPxCON1: MSSPx CONTROL REGISTER 1 (SPI MODE)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
WCOL SSPOV(1) SSPEN(2) CKP SSPM3(3) SSPM2(3) SSPM1(3) SSPM0(3)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 WCOL: Write Collision Detect bit
1 = The SSPxBUF register is written while it is still transmitting the previous word (must be cleared in
software)
0 = No collision
bit 6 SSPOV: Receive Overflow Indicator bit(1)
SPI Slave mode:
1 = A new byte is received while the SSPxBUF register is still holding the previous data. In case of
overflow, the data in SSPxSR is lost. Overflow can only occur in Slave mode. The user must read
the SSPxBUF, even if only transmitting data, to avoid setting overflow (must be cleared in
software).
0 = No overflow
bit 5 SSPEN: Master Synchronous Serial Port Enable bit(2)
1 = Enables serial port and configures SCKx, SDOx, SDIx and SSx as serial port pins
0 = Disables serial port and configures these pins as I/O port pins
bit 4 CKP: Clock Polarity Select bit
1 = Idle state for clock is a high level
0 = Idle state for clock is a low level
bit 3-0 SSPM3:SSPM0: Master Synchronous Serial Port Mode Select bits(3)
0101 = SPI Slave mode, clock = SCKx pin, SSx pin control disabled, SSx can be used as I/O pin
0100 = SPI Slave mode, clock = SCKx pin, SSx pin control enabled
0011 = SPI Master mode, clock = TMR2 output/2
0010 = SPI Master mode, clock = FOSC/64
0001 = SPI Master mode, clock = FOSC/16
0000 = SPI Master mode, clock = FOSC/4
Note 1: In Master mode, the overflow bit is not set since each new reception (and transmission) is initiated by
writing to the SSPxBUF register.
2: When enabled, these pins must be properly configured as input or output.
3: Bit combinations not specifically listed here are either reserved or implemented in I2C mode only.
PIC18F87J11 FAMILY
DS39778C-page 224 Preliminary © 2008 Microchip Technology Inc.
19.3.2 OPERATION
When initializing the SPI, several options need to be
specified. This is done by programming the appropriate
control bits (SSPxCON1<5:0> and SSPxSTAT<7:6>).
These control bits allow the following to be specified:
Master mode (SCKx is the clock output)
Slave mode (SCKx is the clock input)
Clock Polarity (Idle state of SCKx)
Data Input Sample Phase (middle or end of data
output time)
Clock Edge (output data on rising/falling edge of
SCKx)
Clock Rate (Master mode only)
Slave Select mode (Slave mode only)
Each MSSP module consists of a transmit/receive shift
register (SSPxSR) and a buffer register (SSPxBUF).
The SSPxSR shifts the data in and out of the device,
MSb first. The SSPxBUF holds the data that was
written to the SSPxSR until the received data is ready.
Once the 8 bits of data have been received, that byte is
moved to the SSPxBUF register. Then, the Buffer Full
detect bit, BF (SSPxSTAT<0>) and the interrupt flag bit,
SSPxIF, are set. This double-buffering of the received
data (SSPxBUF) allows the next byte to start reception
before reading the data that was just received. Any
write to the SSPxBUF register during transmis-
sion/reception of data will be ignored and the Write
Collision Detect bit, WCOL (SSPxCON1<7>), will be
set. User software must clear the WCOL bit so that it
can be determined if the following write(s) to the
SSPxBUF register completed successfully.
When the application software is expecting to receive
valid data, the SSPxBUF should be read before the next
byte of data to transfer is written to the SSPxBUF. The
Buffer Full bit, BF (SSPxSTAT<0>), indicates when
SSPxBUF has been loaded with the received data
(transmission is complete). When the SSPxBUF is read,
the BF bit is cleared. This data may be irrelevant if the
SPI is only a transmitter. Generally, the MSSP interrupt
is used to determine when the transmission/reception
has completed. If the interrupt method is not going to be
used, then software polling can be done to ensure that a
write collision does not occur. Example 19-1 shows the
loading of the SSPxBUF (SSPxSR) for data
transmission.
The SSPxSR is not directly readable or writable and
can only be accessed by addressing the SSPxBUF
register. Additionally, the SSPxSTAT register indicates
the various status conditions.
19.3.3 OPEN-DRAIN OUTPUT OPTION
The drivers for the SDOx output and SCKx clock pins
can be optionally configured as open-drain outputs.
This feature allows the voltage level on the pin to be
pulled to a higher level through an external pull-up
resistor, and allows the output to communicate with
external circuits without the need for additional level
shifters. For more information, see Section 10.1.4
“Open-Drain Outputs”.
The open-drain output option is controlled by the
SPI2OD and SPI1OD bits (ODCON3<1:0>). Setting an
SPIxOD bit configures the SDOx and SCKx pins for the
corresponding module for open-drain operation.
The ODCON3 register shares the same address as the
T1CON register. The ODCON3 register is accessed by
setting the ADSHR bit in the WDTCON register
(WDTCON<4>).
EXAMPLE 19-1: LOADING THE SSP1BUF (SSP1SR) REGISTER
LOOP BTFSS SSP1STAT, BF ;Has data been received (transmit complete)?
BRA LOOP ;No
MOVF SSP1BUF, W ;WREG reg = contents of SSP1BUF
MOVWF RXDATA ;Save in user RAM, if data is meaningful
MOVF TXDATA, W ;W reg = contents of TXDATA
MOVWF SSP1BUF ;New data to xmit
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 225
PIC18F87J11 FAMILY
19.3.4 ENABLING SPI I/O
To enable the serial port, MSSP Enable bit, SSPEN
(SSPxCON1<5>), must be set. To reset or reconfigure
SPI mode, clear the SSPEN bit, reinitialize the
SSPxCON registers and then set the SSPEN bit. This
configures the SDIx, SDOx, SCKx and SSx pins as
serial port pins. For the pins to behave as the serial port
function, some must have their data direction bits (in
the TRIS register) appropriately programmed as
follows:
SDIx is automatically controlled by the
SPI module
SDOx must have the TRISC<5> or TRISD<4> bit
cleared
SCKx (Master mode) must have the TRISC<3> or
TRISD<6>bit cleared
SCKx (Slave mode) must have the TRISC<3> or
TRISD<6> bit set
SSx must have the TRISF<7> or TRISD<7> bit
set
Any serial port function that is not desired may be
overridden by programming the corresponding Data
Direction (TRIS) register to the opposite value.
19.3.5 TYPICAL CONNECTION
Figure 19-2 shows a typical connection between two
microcontrollers. The master controller (Processor 1)
initiates the data transfer by sending the SCKx signal.
Data is shifted out of both shift registers on their pro-
grammed clock edge and latched on the opposite edge
of the clock. Both processors should be programmed to
the same Clock Polarity (CKP), then both controllers
would send and receive data at the same time.
Whether the data is meaningful (or dummy data)
depends on the application software. This leads to
three scenarios for data transmission:
Master sends data Slave sends dummy data
Master sends data Slave sends data
Master sends dummy data Slave sends data
FIGURE 19-2: SPI MASTER/SLAVE CONNECTION
Serial Input Buffer
(SSPxBUF)
Shift Register
(SSPxSR)
MSb LSb
SDOx
SDIx
PROCESSOR 1
SCKx
SPI Master SSPM3:SSPM0 = 00xxb
Serial Input Buffer
(SSPxBUF)
Shift Register
(SSPxSR)
LSb
MSb
SDIx
SDOx
PROCESSOR 2
SCKx
SPI Slave SSPM3:SSPM0 = 010xb
Serial Clock
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DS39778C-page 226 Preliminary © 2008 Microchip Technology Inc.
19.3.6 MASTER MODE
The master can initiate the data transfer at any time
because it controls the SCKx. The master determines
when the slave (Processor 1, Figure 19-2) is to
broadcast data by the software protocol.
In Master mode, the data is transmitted/received as
soon as the SSPxBUF register is written to. If the SPI
is only going to receive, the SDOx output could be dis-
abled (programmed as an input). The SSPxSR register
will continue to shift in the signal present on the SDIx
pin at the programmed clock rate. As each byte is
received, it will be loaded into the SSPxBUF register as
if a normal received byte (interrupts and status bits
appropriately set). This could be useful in receiver
applications as a “Line Activity Monitor” mode.
The clock polarity is selected by appropriately
programming the CKP bit (SSPxCON1<4>). This then,
would give waveforms for SPI communication as
shown in Figure 19-3, Figure 19-5 and Figure 19-6,
where the MSB is transmitted first. In Master mode, the
SPI clock rate (bit rate) is user programmable to be one
of the following:
•F
OSC/4 (or TCY)
•FOSC/16 (or 4 • TCY)
•F
OSC/64 (or 16 • TCY)
Timer2 output/2
This allows a maximum data rate (at 40 MHz) of
10.00 Mbps.
Figure 19-3 shows the waveforms for Master mode.
When the CKE bit is set, the SDOx data is valid before
there is a clock edge on SCKx. The change of the input
sample is shown based on the state of the SMP bit. The
time when the SSPxBUF is loaded with the received
data is shown.
FIGURE 19-3: SPI MODE WAVEFORM (MASTER MODE)
SCKx
(CKP = 0
SCKx
(CKP = 1
SCKx
(CKP = 0
SCKx
(CKP = 1
4 Clock
Modes
Input
Sample
Input
Sample
SDIx
bit 7 bit 0
SDOx bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
bit 7
SDIx
SSPxIF
(SMP = 1)
(SMP = 0)
(SMP = 1)
CKE = 1)
CKE = 0)
CKE = 1)
CKE = 0)
(SMP = 0)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SDOx bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
(CKE = 0)
(CKE = 1)
Next Q4 Cycle
after Q2
bit 0
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 227
PIC18F87J11 FAMILY
19.3.7 SLAVE MODE
In Slave mode, the data is transmitted and received as
the external clock pulses appear on SCKx. When the
last bit is latched, the SSPxIF interrupt flag bit is set.
While in Slave mode, the external clock is supplied by
the external clock source on the SCKx pin. This exter-
nal clock must meet the minimum high and low times
as specified in the electrical specifications.
While in Sleep mode, the slave can transmit/receive
data. When a byte is received, the device can be
configured to wake-up from Sleep.
19.3.8 SLAVE SELECT
SYNCHRONIZATION
The SSx pin allows a Synchronous Slave mode. The
SPI must be in Slave mode with the SSx pin control
enabled (SSPxCON1<3:0> = 04h). When the SSx pin
is low, transmission and reception are enabled and the
SDOx pin is driven. When the SSx pin goes high, the
SDOx pin is no longer driven, even if in the middle of a
transmitted byte and becomes a floating output. Exter-
nal pull-up/pull-down resistors may be desirable
depending on the application.
When the SPI module resets, the bit counter is forced
to ‘0’. This can be done by either forcing the SSx pin to
a high level or clearing the SSPEN bit.
To emulate two-wire communication, the SDOx pin can
be connected to the SDIx pin. When the SPI needs to
operate as a receiver, the SDOx pin can be configured
as an input. This disables transmissions from the
SDOx. The SDIx can always be left as an input (SDI
function) since it cannot create a bus conflict.
FIGURE 19-4: SLAVE SYNCHRONIZATION WAVEFORM
Note 1: When the SPI is in Slave mode
with SSx pin control enabled
(SSPxCON1<3:0> = 0100), the SPI
module will reset if the SSx pin is set to VDD.
2: If the SPI is used in Slave mode with CKE
set, then the SSx pin control must be
enabled.
SCKx
(CKP = 1
SCKx
(CKP = 0
Input
Sample
SDIx
bit 7
SDOx bit 7 bit 6 bit 7
SSPxIF
Interrupt
(SMP = 0)
CKE = 0)
CKE = 0)
(SMP = 0)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SSx
Flag
bit 0
bit 7
bit 0
Next Q4 Cycle
after Q2
PIC18F87J11 FAMILY
DS39778C-page 228 Preliminary © 2008 Microchip Technology Inc.
FIGURE 19-5: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)
FIGURE 19-6: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)
SCKx
(CKP = 1
SCKx
(CKP = 0
Input
Sample
SDIx
bit 7
SDOx bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
SSPxIF
Interrupt
(SMP = 0)
CKE = 0)
CKE = 0)
(SMP = 0)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SSx
Flag
Optional
Next Q4 Cycle
after Q2
bit 0
SCKx
(CKP = 1
SCKx
(CKP = 0
Input
Sample
SDIx
bit 7 bit 0
SDOx bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
SSPxIF
Interrupt
(SMP = 0)
CKE = 1)
CKE = 1)
(SMP = 0)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SSx
Flag
Not Optional
Next Q4 Cycle
after Q2
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 229
PIC18F87J11 FAMILY
19.3.9 OPERATION IN POWER-MANAGED
MODES
In SPI Master mode, module clocks may be operating
at a different speed than when in full-power mode; in
the case of the Sleep mode, all clocks are halted.
In Idle modes, a clock is provided to the peripherals.
That clock can be from the primary clock source, the
secondary clock (Timer1 oscillator) or the INTOSC
source. See Section 2.3 “Clock Sources and
Oscillator Switching” for additional information.
In most cases, the speed that the master clocks SPI
data is not important; however, this should be
evaluated for each system.
If MSSP interrupts are enabled, they can wake the con-
troller from Sleep mode, or one of the Idle modes, when
the master completes sending data. If an exit from
Sleep or Idle mode is not desired, MSSP interrupts
should be disabled.
If the Sleep mode is selected, all module clocks are
halted and the transmission/reception will remain in
that state until the device wakes. After the device
returns to Run mode, the module will resume
transmitting and receiving data.
In SPI Slave mode, the SPI Transmit/Receive Shift
register operates asynchronously to the device. This
allows the device to be placed in any power-managed
mode and data to be shifted into the SPI Trans-
mit/Receive Shift register. When all 8 bits have been
received, the MSSP interrupt flag bit will be set and if
enabled, will wake the device.
19.3.10 EFFECTS OF A RESET
A Reset disables the MSSP module and terminates the
current transfer.
19.3.11 BUS MODE COMPATIBILITY
Table 19-1 shows the compatibility between the
standard SPI modes and the states of the CKP and
CKE control bits.
TABLE 19-1: SPI BUS MODES
There is also an SMP bit which controls when the data
is sampled.
19.3.12 SPI CLOCK SPEED AND MODULE
INTERACTIONS
Because MSSP1 and MSSP2 are independent
modules, they can operate simultaneously at different
data rates. Setting the SSPM3:SSPM0 bits of the
SSPxCON1 register determines the rate for the
corresponding module.
An exception is when both modules use Timer2 as a
time base in Master mode. In this instance, any
changes to the Timer2 module’s operation will affect
both MSSP modules equally. If different bit rates are
required for each module, the user should select one of
the other three time base options for one of the
modules.
Standard SPI Mode
Terminology
Control Bits State
CKP CKE
0, 0 0 1
0, 1 0 0
1, 0 1 1
1, 1 1 0
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DS39778C-page 230 Preliminary © 2008 Microchip Technology Inc.
TABLE 19-2: REGISTERS ASSOCIATED WITH SPI OPERATION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 58
TRISD TRISD7 TRISD6 TRISD5 TRISD4 TRISD3 TRISD2 TRISD1 TRISD0 58
TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 —58
SSP1BUF MSSP1 Receive Buffer/Transmit Register 56
SSPxCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 56, 59
SSPxSTAT SMP CKE D/A P S R/W UA BF 56, 59
SSP2BUF MSSP2 Receive Buffer/Transmit Register 59
ODCON3(1) —SPI2ODSPI1OD56
Legend: Shaded cells are not used by the MSSP module in SPI mode.
Note 1: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 231
PIC18F87J11 FAMILY
19.4 I2C Mode
The MSSP module in I2C mode fully implements all
master and slave functions (including general call
support), and provides interrupts on Start and Stop bits
in hardware to determine a free bus (multi-master
function). The MSSP module implements the standard
mode specifications, as well as 7-bit and 10-bit
addressing.
Two pins are used for data transfer:
Serial Clock (SCLx) – RC3/SCK1/SCL1 or
RD6/SCK2/SCL2
Serial Data (SDAx) – RC4/SDI1/SDA1 or
RD5/SDI2/SDA2
The user must configure these pins as inputs by setting
the associated TRIS bits.
FIGURE 19-7: MSSP BLOCK DIAGRAM
(I2C™ MODE)
19.4.1 REGISTERS
The MSSP module has six registers for I2C operation.
These are:
MSSPx Control Register 1 (SSPxCON1)
MSSPx Control Register 2 (SSPxCON2)
MSSPx Status Register (SSPxSTAT)
Serial Receive/Transmit Buffer Register
(SSPxBUF)
MSSPx Shift Register (SSPxSR) – Not directly
accessible
MSSPx Address Register (SSPxADD)
•I
2C Slave Address Mask Register (SSPxMSK)
SSPxCON1, SSPxCON2 and SSPxSTAT are the
control and status registers in I2C mode operation. The
SSPxCON1 and SSPxCON2 registers are readable and
writable. The lower 6 bits of the SSPxSTAT are
read-only. The upper two bits of the SSPxSTAT are
read/write.
SSPxSR is the shift register used for shifting data in or
out. SSPxBUF is the buffer register to which data
bytes are written to or read from.
SSPxADD contains the slave device address when the
MSSP is configured in I2C Slave mode. When the
MSSP is configured in Master mode, the lower seven
bits of SSPxADD act as the Baud Rate Generator
reload value.
SSPxMSK holds the slave address mask value when
the module is configured for 7-bit Address Masking
mode. While it is a separate register, it shares the same
SFR address as SSPxADD; it is only accessible when
the SSPM3:SSPM0 bits are specifically set to permit
access. Additional details are provided in
Section 19.4.3.4 “7-Bit Address Masking Mode”.
In receive operations, SSPxSR and SSPxBUF
together, create a double-buffered receiver. When
SSPxSR receives a complete byte, it is transferred to
SSPxBUF and the SSPxIF interrupt is set.
During transmission, the SSPxBUF is not
double-buffered. A write to SSPxBUF will write to both
SSPxBUF and SSPxSR.
Read Write
SSPxSR reg
Match Detect
SSPxADD reg
SSPxBUF reg
Internal
Data Bus
Addr Match
Set, Reset
S, P bits
(SSPxSTAT reg)
Shift
Clock
MSb LSb
Note: Only port I/O names are used in this diagram for
the sake of brevity. Refer to the text for a full list of
multiplexed functions.
SCLx
SDAx
Start and
Stop bit Detect
Address Mask
PIC18F87J11 FAMILY
DS39778C-page 232 Preliminary © 2008 Microchip Technology Inc.
REGISTER 19-3: SSPxSTAT: MSSPx STATUS REGISTER (I2C™ MODE)
R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0
SMP CKE D/A P(1) S(1) R/W(2,3) UA BF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SMP: Slew Rate Control bit
In Master or Slave mode:
1 = Slew rate control disabled for Standard Speed mode (100 kHz and 1 MHz)
0 = Slew rate control enabled for High-Speed mode (400 kHz)
bit 6 CKE: SMBus Select bit
In Master or Slave mode:
1 = Enable SMBus specific inputs
0 = Disable SMBus specific inputs
bit 5 D/A: Data/Address bit
In Master mode:
Reserved.
In Slave mode:
1 = Indicates that the last byte received or transmitted was data
0 = Indicates that the last byte received or transmitted was address
bit 4 P: Stop bit(1)
1 = Indicates that a Stop bit has been detected last
0 = Stop bit was not detected last
bit 3 S: Start bit(1)
1 = Indicates that a Start bit has been detected last
0 = Start bit was not detected last
bit 2 R/W: Read/Write Information bit(2,3)
In Slave mode:
1 = Read
0 = Write
In Master mode:
1 = Transmit is in progress
0 = Transmit is not in progress
bit 1 UA: Update Address bit (10-Bit Slave mode only)
1 = Indicates that the user needs to update the address in the SSPxADD register
0 = Address does not need to be updated
bit 0 BF: Buffer Full Status bit
In Transmit mode:
1 = SSPxBUF is full
0 = SSPxBUF is empty
In Receive mode:
1 = SSPxBUF is full (does not include the ACK and Stop bits)
0 = SSPxBUF is empty (does not include the ACK and Stop bits)
Note 1: This bit is cleared on Reset and when SSPEN is cleared.
2: This bit holds the R/W bit information following the last address match. This bit is only valid from the
address match to the next Start bit, Stop bit or not ACK bit.
3: ORing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the MSSPx is in Active mode.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 233
PIC18F87J11 FAMILY
REGISTER 19-4: SSPxCON1: MSSPx CONTROL REGISTER 1 (I2C™ MODE)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
WCOL SSPOV SSPEN(1) CKP SSPM3(2) SSPM2(2) SSPM1(2) SSPM0(2)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 WCOL: Write Collision Detect bit
In Master Transmit mode:
1 = A write to the SSPxBUF register was attempted while the I2C conditions were not valid for a
transmission to be started (must be cleared in software)
0 = No collision
In Slave Transmit mode:
1 = The SSPxBUF register is written while it is still transmitting the previous word (must be cleared in
software)
0 = No collision
In Receive mode (Master or Slave modes):
This is a “don’t care” bit.
bit 6 SSPOV: Receive Overflow Indicator bit
In Receive mode:
1 = A byte is received while the SSPxBUF register is still holding the previous byte (must be cleared in
software)
0 = No overflow
In Transmit mode:
This is a “don’t care” bit in Transmit mode.
bit 5 SSPEN: Master Synchronous Serial Port Enable bit(1)
1 = Enables the serial port and configures the SDAx and SCLx pins as the serial port pins
0 = Disables serial port and configures these pins as I/O port pins
bit 4 CKP: SCKx Release Control bit
In Slave mode:
1 = Releases clock
0 = Holds clock low (clock stretch), used to ensure data setup time
In Master mode:
Unused in this mode.
bit 3-0 SSPM3:SSPM0: Master Synchronous Serial Port Mode Select bits(2)
1111 = I2C Slave mode, 10-bit address with Start and Stop bit interrupts enabled
1110 = I2C Slave mode, 7-bit address with Start and Stop bit interrupts enabled
1011 = I2C Firmware Controlled Master mode (Slave Idle)
1001 = Load SSPMSK register at SSPADD SFR address(3,4)
1000 = I2C Master mode, clock = FOSC/(4 * (SSPxADD + 1))
0111 = I2C Slave mode, 10-bit address
0110 = I2C Slave mode, 7-bit address
Note 1: When enabled, the SDAx and SCLx pins must be configured as inputs.
2: Bit combinations not specifically listed here are either reserved or implemented in SPI mode only.
3: When SSPM3:SSPM0 = 1001, any reads or writes to the SSPxADD SFR address actually accesses the
SSPxMSK register.
4: This mode is only available when 7-Bit Address Masking mode is selected (MSSPMSK Configuration bit
is ‘1’).
PIC18F87J11 FAMILY
DS39778C-page 234 Preliminary © 2008 Microchip Technology Inc.
REGISTER 19-5: SSPxCON2: MSSPx CONTROL REGISTER 2 (I2C™ MASTER MODE)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
GCEN ACKSTAT ACKDT(1) ACKEN(2) RCEN(2) PEN(2) RSEN(2) SEN(2)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 GCEN: General Call Enable bit
Unused in Master mode.
bit 6 ACKSTAT: Acknowledge Status bit (Master Transmit mode only)
1 = Acknowledge was not received from slave
0 = Acknowledge was received from slave
bit 5 ACKDT: Acknowledge Data bit (Master Receive mode only)(1)
1 = Not Acknowledge
0 = Acknowledge
bit 4 ACKEN: Acknowledge Sequence Enable bit(2)
1 = Initiates Acknowledge sequence on SDAx and SCLx pins and transmit ACKDT data bit.
Automatically cleared by hardware.
0 = Acknowledge sequence Idle
bit 3 RCEN: Receive Enable bit (Master Receive mode only)(2)
1 = Enables Receive mode for I2C
0 = Receive Idle
bit 2 PEN: Stop Condition Enable bit(2)
1 = Initiates Stop condition on SDAx and SCLx pins. Automatically cleared by hardware.
0 = Stop condition Idle
bit 1 RSEN: Repeated Start Condition Enable bit(2)
1 = Initiates Repeated Start condition on SDAx and SCLx pins. Automatically cleared by hardware.
0 = Repeated Start condition Idle
bit 0 SEN: Start Condition Enable bit(2)
1 = Initiates Start condition on SDAx and SCLx pins. Automatically cleared by hardware.
0 = Start condition Idle
Note 1: Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive.
2: If the I2C module is active, these bits may not be set (no spooling) and the SSPxBUF may not be written
(or writes to the SSPxBUF are disabled).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 235
PIC18F87J11 FAMILY
REGISTER 19-6: SSPxCON2: MSSPx CONTROL REGISTER 2 (I2C™ SLAVE MODE)
REGISTER 19-7: SSPxMSK: I2C™ SLAVE ADDRESS MASK REGISTER (7-BIT MASKING MODE)(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
GCEN ACKSTAT ADMSK5 ADMSK4 ADMSK3 ADMSK2 ADMSK1 SEN(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 GCEN: General Call Enable bit
1 = Enables interrupt when a general call address (0000h) is received in the SSPSR
0 = General call address disabled
bit 6 ACKSTAT: Acknowledge Status bit
Unused in Slave mode.
bit 5-2 ADMSK5:ADMSK2: Slave Address Mask Select bits (5-Bit Address Masking mode)
1 = Masking of corresponding bits of SSPxADD enabled
0 = Masking of corresponding bits of SSPxADD disabled
bit 1 ADMSK1: Slave Address Least Significant bit(s) Mask Select bit
In 7-Bit Addressing mode:
1 = Masking of SSPxADD<1> only enabled
0 = Masking of SSPxADD<1> only disabled
In 10-Bit Addressing mode:
1 = Masking of SSPxADD<1:0> enabled
0 = Masking of SSPxADD<1:0> disabled
bit 0 SEN: Stretch Enable bit(1)
1 = Clock stretching is enabled for both slave transmit and slave receive (stretch enabled)
0 = Clock stretching is disabled
Note 1: If the I2C module is active, this bit may not be set (no spooling) and the SSPBUF may not be written (or
writes to the SSPxBUF are disabled).
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0(2)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 MSK7:MSK0: Slave Address Mask Select bit
1 = Masking of corresponding bit of SSPxADD enabled
0 = Masking of corresponding bit of SSPxADD disabled
Note 1: This register shares the same SFR address as SSPxADD, and is only addressable in select MSSPx
operating modes. See Section 19.4.3.4 “7-Bit Address Masking Mode” for more details.
2: MSK0 is not used as a mask bit in 7-bit addressing.
PIC18F87J11 FAMILY
DS39778C-page 236 Preliminary © 2008 Microchip Technology Inc.
19.4.2 OPERATION
The MSSP module functions are enabled by setting the
MSSP Enable bit, SSPEN (SSPxCON1<5>).
The SSPxCON1 register allows control of the I2C
operation. Four mode selection bits (SSPxCON1<3:0>)
allow one of the following I2C modes to be selected:
•I
2C Master mode, clock
•I
2C Slave mode (7-bit address)
•I
2C Slave mode (10-bit address)
•I
2C Slave mode (7-bit address) with Start and
Stop bit interrupts enabled
•I
2C Slave mode (10-bit address) with Start and
Stop bit interrupts enabled
•I
2C Firmware Controlled Master mode, slave is
Idle
Selection of any I2C mode with the SSPEN bit set
forces the SCLx and SDAx pins to be open-drain,
provided these pins are programmed as inputs by
setting the appropriate TRISC or TRISD bits. To ensure
proper operation of the module, pull-up resistors must
be provided externally to the SCLx and SDAx pins.
19.4.3 SLAVE MODE
In Slave mode, the SCLx and SDAx pins must be
configured as inputs (TRISC<4:3> set). The MSSP
module will override the input state with the output data
when required (slave-transmitter).
The I2C Slave mode hardware will always generate an
interrupt on an address match. Address masking will
allow the hardware to generate an interrupt for more
than one address (up to 31 in 7-bit addressing and up
to 63 in 10-bit addressing). Through the mode select
bits, the user can also choose to interrupt on Start and
Stop bits.
When an address is matched, or the data transfer after
an address match is received, the hardware auto-
matically will generate the Acknowledge (ACK) pulse
and load the SSPxBUF register with the received value
currently in the SSPxSR register.
Any combination of the following conditions will cause
the MSSP module not to give this ACK pulse:
The Buffer Full bit, BF (SSPxSTAT<0>), was set
before the transfer was received.
The overflow bit, SSPOV (SSPxCON1<6>), was
set before the transfer was received.
In this case, the SSPxSR register value is not loaded
into the SSPxBUF, but bit SSPxIF is set. The BF bit is
cleared by reading the SSPxBUF register, while bit
SSPOV is cleared through software.
The SCLx clock input must have a minimum high and
low for proper operation. The high and low times of the
I2C specification, as well as the requirement of the
MSSP module, are shown in timing parameter 100 and
parameter 101.
19.4.3.1 Addressing
Once the MSSP module has been enabled, it waits for
a Start condition to occur. Following the Start condition,
the 8 bits are shifted into the SSPxSR register. All
incoming bits are sampled with the rising edge of the
clock (SCLx) line. The value of register, SSPxSR<7:1>,
is compared to the value of the SSPxADD register. The
address is compared on the falling edge of the eighth
clock (SCLx) pulse. If the addresses match and the BF
and SSPOV bits are clear, the following events occur:
1. The SSPxSR register value is loaded into the
SSPxBUF register.
2. The Buffer Full bit, BF, is set.
3. An ACK pulse is generated.
4. The MSSP Interrupt Flag bit, SSPxIF, is set (and
interrupt is generated, if enabled) on the falling
edge of the ninth SCLx pulse.
In 10-Bit Addressing mode, two address bytes need to
be received by the slave. The five Most Significant bits
(MSbs) of the first address byte specify if this is a 10-bit
address. Bit R/W (SSPxSTAT<2>) must specify a write
so the slave device will receive the second address
byte. For a 10-bit address, the first byte would equal
11110 A9 A8 0’, where ‘A9’ and ‘A8’ are the two
MSbs of the address. The sequence of events for 10-bit
addressing is as follows, with steps 7 through 9 for the
slave-transmitter:
1. Receive first (high) byte of address (bits SSPxIF,
BF and UA are set on address match).
2. Update the SSPxADD register with second (low)
byte of address (clears bit UA and releases the
SCLx line).
3. Read the SSPxBUF register (clears bit, BF) and
clear flag bit, SSPxIF.
4. Receive second (low) byte of address (bits
SSPxIF, BF and UA are set).
5. Update the SSPxADD register with the first
(high) byte of address. If match releases SCLx
line, this will clear bit UA.
6. Read the SSPxBUF register (clears bit BF) and
clear flag bit SSPxIF.
7. Receive Repeated Start condition.
8. Receive first (high) byte of address (bits SSPxIF
and BF are set).
9. Read the SSPxBUF register (clears bit BF) and
clear flag bit, SSPxIF.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 237
PIC18F87J11 FAMILY
19.4.3.2 Address Masking Modes
Masking an address bit causes that bit to become a
“don’t care”. When one address bit is masked, two
addresses will be Acknowledged and cause an
interrupt. It is possible to mask more than one address
bit at a time, which greatly expands the number of
addresses Acknowledged.
The I2C Slave behaves the same way whether address
masking is used or not. However, when address
masking is used, the I2C slave can Acknowledge
multiple addresses and cause interrupts. When this
occurs, it is necessary to determine which address
caused the interrupt by checking the SSPxBUF.
The PIC18F87J11 Family of devices is capable of using
two different Address Masking modes in I2C Slave
operation: 5-Bit Address Masking and 7-Bit Address
Masking. The Masking mode is selected at device
configuration using the MSSPMSK Configuration bit.
The default device configuration is 7-Bit Address
Masking.
Both Masking modes, in turn, support address masking
of 7-bit and 10-bit addresses. The combination of
Masking modes and addresses provide different
ranges of Acknowledgable addresses for each
combination.
While both Masking modes function in roughly the
same manner, the way they use address masks are
different.
19.4.3.3 5-Bit Address Masking Mode
As the name implies, 5-Bit Address Masking mode
uses an address mask of up to 5 bits to create a range
of addresses to be Acknowledged, using bits 5 through
1 of the incoming address. This allows the module to
Acknowledge up to 31 addresses when using 7-bit
addressing, or 63 addresses with 10-bit addressing
(see Example 19-2). This Masking mode is selected
when the MSSPMSK Configuration bit is programmed
(‘0’).
The address mask in this mode is stored in the
SSPxCON2 register, which stops functioning as a con-
trol register in I2C Slave mode (Register 19-6). In 7-Bit
Address Masking mode, address mask bits,
ADMSK<5:1> (SSPxCON2<5:1>), mask the corre-
sponding address bits in the SSPxADD register. For
any ADMSK bits that are set (ADMSK<n> = 1), the cor-
responding address bit is ignored (SSPxADD<n> = x).
For the module to issue an address Acknowledge, it is
sufficient to match only on addresses that do not have
an active address mask.
In 10-Bit Address Masking mode, bits ADMSK<5:2>
mask the corresponding address bits in the SSPxADD
register. In addition, ADMSK1 simultaneously masks
the two LSbs of the address (SSPxADD<1:0>). For any
ADMSK bits that are active (ADMSK<n> = 1), the cor-
responding address bit is ignored (SPxADD<n> = x).
Also note, that although in 10-Bit Address Masking
mode, the upper address bits reuse part of the
SSPxADD register bits. The address mask bits do not
interact with those bits; they only affect the lower
address bits.
EXAMPLE 19-2: ADDRESS MASKING EXAMPLES IN 5-BIT MASKING MODE
Note 1: ADMSK1 masks the two Least Significant
bits of the address.
2: The two Most Significant bits of the
address are not affected by address
masking.
7-Bit Addressing:
SSPADD<7:1>= A0h (1010000) (SSPADD<0> is assumed to be ‘0’)
ADMSK<5:1> = 00111
Addresses Acknowledged: A0h, A2h, A4h, A6h, A8h, AAh, ACh, AEh
10-Bit Addressing:
SSPADD<7:0> = A0h (10100000) (The two MSb of the address are ignored in this example, since they
are not affected by masking)
ADMSK<5:1> = 00111
Addresses Acknowledged: A0h, A1h, A2h, A3h, A4h, A5h, A6h, A7h, A8h, A9h, AAh, ABh, ACh, ADh,
AEh, AFh
PIC18F87J11 FAMILY
DS39778C-page 238 Preliminary © 2008 Microchip Technology Inc.
19.4.3.4 7-Bit Address Masking Mode
Unlike 5-bit masking, 7-Bit Address Masking mode
uses a mask of up to 8 bits (in 10-bit addressing) to
define a range of addresses than can be Acknowl-
edged, using the lowest bits of the incoming address.
This allows the module to Acknowledge up to 127 dif-
ferent addresses with 7-bit addressing, or 255 with
10-bit addressing (see Example 19-3). This mode is
the default configuration of the module, and is selected
when MSSPMSK is unprogrammed (1’).
The address mask for 7-Bit Address Masking mode is
stored in the SSPxMSK register, instead of the
SSPxCON2 register. SSPxMSK is a separate hard-
ware register within the module, but it is not directly
addressable. Instead, it shares an address in the SFR
space with the SSPxADD register. To access the
SSPxMSK register, it is necessary to select MSSP
mode,1001’ (SSPCON1<3:0> = 1001), and then read
or write to the location of SSPxADD.
To use 7-Bit Address Masking mode, it is necessary to
initialize SSPxMSK with a value before selecting the
I2C Slave Addressing mode. Thus, the required
sequence of events is:
1. Select SSPxMSK Access mode
(SSPxCON2<3:0> = 1001).
2. Write the mask value to the appropriate
SSPADD register address (FC8h for MSSP1,
F6Eh for MSSP2).
3. Set the appropriate I2C Slave mode
(SSPxCON2<3:0> = 0111 for 10-bit
addressing, 0110 for 7-bit addressing).
Setting or clearing mask bits in SSPxMSK behaves in
the opposite manner of the ADMSK bits in 5-Bit
Address Masking mode. That is, clearing a bit in
SSPxMSK causes the corresponding address bit to be
masked; setting the bit requires a match in that
position. SSPxMSK resets to all ‘1’s upon any Reset
condition and, therefore, has no effect on the standard
MSSP operation until written with a mask value.
With 7-bit addressing, SSPxMSK<7:1> bits mask the
corresponding address bits in the SSPxADD register.
For any SSPxMSK bits that are active
(SSPxMSK<n> = 0), the corresponding SSPxADD
address bit is ignored (SSPxADD<n> = x). For the
module to issue an address Acknowledge, it is suffi-
cient to match only on addresses that do not have an
active address mask.
With 10-bit addressing, SSPxMSK<7:0> bits mask the
corresponding address bits in the SSPxADD register.
For any SSPxMSK bits that are active (= 0), the corre-
sponding SSPxADD address bit is ignored
(SSPxADD<n> = x).
EXAMPLE 19-3: ADDRESS MASKING EXAMPLES IN 7-BIT MASKING MODE
Note: The two Most Significant bits of the
address are not affected by address
masking.
7-Bit Addressing:
SSPxADD<7:1> = 1010 000
SSPxMSK<7:1> = 1111 001
Addresses Acknowledged = A8h, A6h, A4h, A0h
10-Bit Addressing:
SSPxADD<7:0> = 1010 0000 (The two MSb are ignored in this example since they are not affected)
SSPxMSK<5:1> = 1111 0
Addresses Acknowledged = A8h, A6h, A4h, A0h
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 239
PIC18F87J11 FAMILY
19.4.3.5 Reception
When the R/W bit of the address byte is clear and an
address match occurs, the R/W bit of the SSPxSTAT
register is cleared. The received address is loaded into
the SSPxBUF register and the SDAx line is held low
(ACK).
When the address byte overflow condition exists, then
the no Acknowledge (ACK) pulse is given. An overflow
condition is defined as either bit, BF (SSPxSTAT<0>),
is set or bit, SSPOV (SSPxCON1<6>), is set.
An MSSP interrupt is generated for each data transfer
byte. The interrupt flag bit, SSPxIF, must be cleared in
software. The SSPxSTAT register is used to determine
the status of the byte.
If SEN is enabled (SSPxCON2<0> = 1), SCLx will be
held low (clock stretch) following each data transfer. The
clock must be released by setting bit, CKP
(SSPxCON1<4>). See Section 19.4.4 “Clock
Stretching” for more details.
19.4.3.6 Transmission
When the R/W bit of the incoming address byte is set
and an address match occurs, the R/W bit of the
SSPxSTAT register is set. The received address is
loaded into the SSPxBUF register. The ACK pulse will
be sent on the ninth bit and pin SCLx is held low regard-
less of SEN (see Section 19.4.4 “Clock Stretching”
for more details). By stretching the clock, the master
will be unable to assert another clock pulse until the
slave is done preparing the transmit data. The transmit
data must be loaded into the SSPxBUF register which
also loads the SSPxSR register. Then, pin SCLx should
be enabled by setting bit, CKP (SSPxCON1<4>). The
eight data bits are shifted out on the falling edge of the
SCLx input. This ensures that the SDAx signal is valid
during the SCLx high time (Figure 19-10).
The ACK pulse from the master-receiver is latched on
the rising edge of the ninth SCLx input pulse. If the
SDAx line is high (not ACK), then the data transfer is
complete. In this case, when the ACK is latched by the
slave, the slave logic is reset and the slave monitors for
another occurrence of the Start bit. If the SDAx line was
low (ACK), the next transmit data must be loaded into
the SSPxBUF register. Again, pin SCLx must be
enabled by setting bit, CKP.
An MSSP interrupt is generated for each data transfer
byte. The SSPxIF bit must be cleared in software and
the SSPxSTAT register is used to determine the status
of the byte. The SSPxIF bit is set on the falling edge of
the ninth clock pulse.
PIC18F87J11 FAMILY
DS39778C-page 240 Preliminary © 2008 Microchip Technology Inc.
FIGURE 19-8: I2C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
SSPOV (SSPxCON1<6>)
S1 234 567 89 1 2 345 67 89 1 23 45 7 89 P
A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D1 D0
ACK
Receiving Data
ACK
Receiving Data
R/W = 0
ACK
Receiving Address
Cleared in software
SSPxBUF is read
Bus master
terminates
transfer
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
D2
6
CKP (SSPxCON<4>)
(CKP does not reset to ‘0’ when SEN = 0)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 241
PIC18F87J11 FAMILY
FIGURE 19-9: I2C™ SLAVE MODE TIMING WITH SEN = 0 AND ADMSK<5:1> = 01011
(RECEPTION, 7-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
SSPOV (SSPxCON1<6>)
S12345678912345678912345 789 P
A7 A6 A5 X A3 X X D7D6D5D4D3D2D1 D0 D7D6D5D4D3 D1D0
ACK
Receiving Data
ACK
Receiving Data
R/W = 0
ACK
Receiving Address
Cleared in software
SSPxBUF is read
Bus master
terminates
transfer
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
D2
6
CKP (SSPxCON<4>)
(CKP does not reset to ‘0’ when SEN = 0)
Note 1: x = Don’t care (i.e., address bit can either be a ‘1’ or a ‘0’).
2: In this example, an address equal to A7.A6.A5.X.A3.X.X will be Acknowledged and cause an interrupt.
PIC18F87J11 FAMILY
DS39778C-page 242 Preliminary © 2008 Microchip Technology Inc.
FIGURE 19-10: I2C™ SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)
SDAx
SCLx
BF (SSPxSTAT<0>)
A6 A5 A4 A3 A2 A1 D6 D5 D4 D3 D2 D1 D0
1 2 3 4 5 6 7 8 2 3 4 5 6 7 8 9
SSPxBUF is written in software
Cleared in software
Data in
sampled
S
ACK
Transmitting Data
R/W = 0
ACK
Receiving Address
A7 D7
9 1
D6 D5 D4 D3 D2 D1 D0
2 3 4 5 6 7 8 9
SSPxBUF is written in software
Cleared in software
From SSPxIF ISR
Transmitting Data
D7
1
CKP (SSPxCON<4>)
P
ACK
CKP is set in software CKP is set in software
SCLx held low
while CPU
responds to SSPxIF
SSPxIF (PIR1<3> or PIR3<7>)
From SSPxIF ISR
Clear by reading
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 243
PIC18F87J11 FAMILY
FIGURE 19-11: I2C™ SLAVE MODE TIMING WITH SEN = 0 AND ADMSK<5:1> = 01001
(RECEPTION, 10-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
S123456789 123456789 12345 789 P
1 1 1 1 0 A9 A8 A7 A6 A5 X A3 A2 X X D7 D6 D5 D4 D3 D1 D0
Receive Data Byte
ACK
R/W = 0
ACK
Receive First Byte of Address
Cleared in software
D2
6
Cleared in software
Receive Second Byte of Address
Cleared by hardware
when SSPxADD is updated
with low byte of address
UA (SSPxSTAT<1>)
Clock is held low until
update of SSPxADD has
taken place
UA is set indicating that
the SSPxADD needs to be
updated
UA is set indicating that
SSPxADD needs to be
updated
Cleared by hardware when
SSPxADD is updated with high
byte of address
SSPxBUF is written with
contents of SSPxSR
Dummy read of SSPxBUF
to clear BF flag
ACK
CKP (SSPxCON<4>)
12345 789
D7 D6 D5 D4 D3 D1 D0
Receive Data Byte
Bus master
terminates
transfer
D2
6
ACK
Cleared in software Cleared in software
SSPOV (SSPxCON1<6>)
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
(CKP does not reset to ‘0 when SEN = 0)
Clock is held low until
update of SSPxADD has
taken place
Note 1: x = Don’t care (i.e., address bit can either be a ‘1’ or a ‘0’).
2: In this example, an address equal to A9.A8.A7.A6.A5.X.A3.A2.X.X will be Acknowledged and cause an interrupt.
3: Note that the Most Significant bits of the address are not affected by the bit masking.
PIC18F87J11 FAMILY
DS39778C-page 244 Preliminary © 2008 Microchip Technology Inc.
FIGURE 19-12: I2C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
S123456789 123456789 12345 789 P
1 1 1 1 0 A9A8 A7 A6A5 A4A3A2A1 A0 D7 D6D5D4D3 D1D0
Receive Data Byte
ACK
R/W = 0
ACK
Receive First Byte of Address
Cleared in software
D2
6
Cleared in software
Receive Second Byte of Address
Cleared by hardware
when SSPxADD is updated
with low byte of address
UA (SSPxSTAT<1>)
Clock is held low until
update of SSPxADD has
taken place
UA is set indicating that
the SSPxADD needs to be
updated
UA is set indicating that
SSPxADD needs to be
updated
Cleared by hardware when
SSPxADD is updated with high
byte of address
SSPxBUF is written with
contents of SSPxSR
Dummy read of SSPxBUF
to clear BF flag
ACK
CKP (SSPxCON<4>)
12345 789
D7 D6 D5 D4 D3 D1 D0
Receive Data Byte
Bus master
terminates
transfer
D2
6
ACK
Cleared in software Cleared in software
SSPOV (SSPxCON1<6>)
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
(CKP does not reset to ‘0 when SEN = 0)
Clock is held low until
update of SSPxADD has
taken place
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 245
PIC18F87J11 FAMILY
FIGURE 19-13: I2C™ SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
S1234 5 6789 1 2345 678 9 12345 7 89 P
1 1 1 1 0 A9A8 A7 A6A5A4A3A2A1 A0 1 1 1 1 0 A8
R/W = 1
ACK
ACK
R/W = 0
ACK
Receive First Byte of Address
Cleared in software
Bus master
terminates
transfer
A9
6
Receive Second Byte of Address
Cleared by hardware when
SSPxADD is updated with low
byte of address
UA (SSPxSTAT<1>)
Clock is held low until
update of SSPxADD has
taken place
UA is set indicating that
the SSPxADD needs to be
updated
UA is set indicating that
SSPxADD needs to be
updated
Cleared by hardware when
SSPxADD is updated with high
byte of address.
SSPxBUF is written with
contents of SSPxSR
Dummy read of SSPxBUF
to clear BF flag
Receive First Byte of Address
12345 789
D7 D6 D5 D4 D3 D1
ACK
D2
6
Transmitting Data Byte
D0
Dummy read of SSPxBUF
to clear BF flag
Sr
Cleared in software
Write of SSPxBUF
initiates transmit
Cleared in software
Completion of
clears BF flag
CKP (SSPxCON1<4>)
CKP is set in software
CKP is automatically cleared in hardware, holding SCLx low
Clock is held low until
update of SSPxADD has
taken place
data transmission
Clock is held low until
CKP is set to ‘1
third address sequence
BF flag is clear
at the end of the
PIC18F87J11 FAMILY
DS39778C-page 246 Preliminary © 2008 Microchip Technology Inc.
19.4.4 CLOCK STRETCHING
Both 7-Bit and 10-Bit Slave modes implement
automatic clock stretching during a transmit sequence.
The SEN bit (SSPxCON2<0>) allows clock stretching
to be enabled during receives. Setting SEN will cause
the SCLx pin to be held low at the end of each data
receive sequence.
19.4.4.1 Clock Stretching for 7-Bit Slave
Receive Mode (SEN = 1)
In 7-Bit Slave Receive mode, on the falling edge of the
ninth clock at the end of the ACK sequence, if the BF
bit is set, the CKP bit in the SSPxCON1 register is
automatically cleared, forcing the SCLx output to be
held low. The CKP bit being cleared to 0’ will assert
the SCLx line low. The CKP bit must be set in the
user’s ISR before reception is allowed to continue. By
holding the SCLx line low, the user has time to service
the ISR and read the contents of the SSPxBUF before
the master device can initiate another receive
sequence. This will prevent buffer overruns from
occurring (see Figure 19-15).
19.4.4.2 Clock Stretching for 10-Bit Slave
Receive Mode (SEN = 1)
In 10-Bit Slave Receive mode, during the address
sequence, clock stretching automatically takes place
but CKP is not cleared. During this time, if the UA bit is
set after the ninth clock, clock stretching is initiated.
The UA bit is set after receiving the upper byte of the
10-bit address and following the receive of the second
byte of the 10-bit address with the R/W bit cleared to
0’. The release of the clock line occurs upon updating
SSPxADD. Clock stretching will occur on each data
receive sequence as described in 7-bit mode.
19.4.4.3 Clock Stretching for 7-Bit Slave
Transmit Mode
The 7-Bit Slave Transmit mode implements clock
stretching by clearing the CKP bit after the falling edge
of the ninth clock if the BF bit is clear. This occurs
regardless of the state of the SEN bit.
The user’s ISR must set the CKP bit before transmis-
sion is allowed to continue. By holding the SCLx line
low, the user has time to service the ISR and load the
contents of the SSPxBUF before the master device
can initiate another transmit sequence (see
Figure 19-10).
19.4.4.4 Clock Stretching for 10-Bit Slave
Transmit Mode
In 10-Bit Slave Transmit mode, clock stretching is
controlled during the first two address sequences by
the state of the UA bit, just as it is in 10-Bit Slave
Receive mode. The first two addresses are followed
by a third address sequence, which contains the
high-order bits of the 10-bit address and the R/W bit
set to1’. After the third address sequence is
performed, the UA bit is not set, the module is now
configured in Transmit mode and clock stretching is
controlled by the BF flag as in 7-Bit Slave Transmit
mode (see Figure 19-13).
Note 1: If the user reads the contents of the
SSPxBUF before the falling edge of the
ninth clock, thus clearing the BF bit, the
CKP bit will not be cleared and clock
stretching will not occur.
2: The CKP bit can be set in software
regardless of the state of the BF bit. The
user should be careful to clear the BF bit
in the ISR before the next receive
sequence in order to prevent an overflow
condition.
Note: If the user polls the UA bit and clears it by
updating the SSPxADD register before the
falling edge of the ninth clock occurs, and
if the user hasn’t cleared the BF bit by
reading the SSPxBUF register before that
time, then the CKP bit will still NOT be
asserted low. Clock stretching on the basis
of the state of the BF bit only occurs during
a data sequence, not an address
sequence.
Note 1: If the user loads the contents of
SSPxBUF, setting the BF bit before the
falling edge of the ninth clock, the CKP bit
will not be cleared and clock stretching
will not occur.
2: The CKP bit can be set in software
regardless of the state of the BF bit.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 247
PIC18F87J11 FAMILY
19.4.4.5 Clock Synchronization and
the CKP bit
When the CKP bit is cleared, the SCLx output is forced
to ‘0’. However, clearing the CKP bit will not assert the
SCLx output low until the SCLx output is already
sampled low. Therefore, the CKP bit will not assert the
SCLx line until an external I2C master device has
already asserted the SCLx line. The SCLx output will
remain low until the CKP bit is set and all other
devices on the I2C bus have deasserted SCLx. This
ensures that a write to the CKP bit will not violate the
minimum high time requirement for SCLx (see
Figure 19-14).
FIGURE 19-14: CLOCK SYNCHRONIZATION TIMING
SDAx
SCLx
DX – 1
DX
WR
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
SSPxCON1
CKP
Master device
deasserts clock
Master device
asserts clock
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DS39778C-page 248 Preliminary © 2008 Microchip Technology Inc.
FIGURE 19-15: I2C™ SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
SSPOV (SSPxCON1<6>)
S1 234 56 789 1 2345 67 89 1 23 45 7 89 P
A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D1 D0
ACK
Receiving Data
ACK
Receiving Data
R/W = 0
ACK
Receiving Address
Cleared in software
SSPxBUF is read
Bus master
terminates
transfer
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
D2
6
CKP (SSPxCON<4>)
CKP
written
to ‘1’ in
If BF is cleared
prior to the falling
edge of the 9th clock,
CKP will not be reset
to ‘0’ and no clock
stretching will occur
software
Clock is held low until
CKP is set to ‘1
Clock is not held low
because buffer full bit is
clear prior to falling edge
of 9th clock
Clock is not held low
because ACK =
1
BF is set after falling
edge of the 9th clock,
CKP is reset to ‘0’ and
clock stretching occurs
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 249
PIC18F87J11 FAMILY
FIGURE 19-16: I2C™ SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 10-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
S123456 789 123456789 12345 789 P
1 1 1 1 0 A9A8 A7 A6 A5A4A3A2A1 A0 D7D6D5D4D3 D1D0
Receive Data Byte
ACK
R/W = 0
ACK
Receive First Byte of Address
Cleared in software
D2
6
Cleared in software
Receive Second Byte of Address
Cleared by hardware when
SSPxADD is updated with low
byte of address after falling edge
UA (SSPxSTAT<1>)
Clock is held low until
update of SSPxADD has
taken place
UA is set indicating that
the SSPxADD needs to be
updated
UA is set indicating that
SSPxADD needs to be
updated
Cleared by hardware when
SSPxADD is updated with high
byte of address after falling edge
SSPxBUF is written with
contents of SSPxSR Dummy read of SSPxBUF
to clear BF flag
ACK
CKP (SSPxCON<4>)
12345 789
D7 D6 D5 D4 D3 D1 D0
Receive Data Byte
Bus master
terminates
transfer
D2
6
ACK
Cleared in software Cleared in software
SSPOV (SSPxCON1<6>)
CKP written to
1
Note: An update of the SSPxADD register before
the falling edge of the ninth clock will have no
effect on UA and UA will remain set.
Note: An update of the SSPxADD
register before the falling
edge of the ninth clock will
have no effect on UA and
UA will remain set.
in software
Clock is held low until
update of SSPxADD has
taken place
of ninth clock
of ninth clock
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
Dummy read of SSPxBUF
to clear BF flag
Clock is held low until
CKP is set to
1
Clock is not held low
because ACK =
1
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DS39778C-page 250 Preliminary © 2008 Microchip Technology Inc.
19.4.5 GENERAL CALL ADDRESS
SUPPORT
The addressing procedure for the I2C bus is such that
the first byte after the Start condition usually
determines which device will be the slave addressed by
the master. The exception is the general call address
which can address all devices. When this address is
used, all devices should, in theory, respond with an
Acknowledge.
The general call address is one of eight addresses
reserved for specific purposes by the I2C protocol. It
consists of all ‘0s with R/W = 0.
The general call address is recognized when the
General Call Enable bit, GCEN, is enabled
(SSPxCON2<7> set). Following a Start bit detect, 8 bits
are shifted into the SSPxSR and the address is
compared against the SSPxADD. It is also compared to
the general call address and fixed in hardware.
If the general call address matches, the SSPxSR is
transferred to the SSPxBUF, the BF flag bit is set
(eighth bit), and on the falling edge of the ninth bit (ACK
bit), the SSPxIF interrupt flag bit is set.
When the interrupt is serviced, the source for the
interrupt can be checked by reading the contents of the
SSPxBUF. The value can be used to determine if the
address was device-specific or a general call address.
In 10-Bit Addressing mode, the SSPxADD is required
to be updated for the second half of the address to
match and the UA bit is set (SSPxSTAT<1>). If the gen-
eral call address is sampled when the GCEN bit is set,
while the slave is configured in 10-Bit Addressing
mode, then the second half of the address is not
necessary, the UA bit will not be set and the slave will
begin receiving data after the Acknowledge
(Figure 19-17).
FIGURE 19-17: SLAVE MODE GENERAL CALL ADDRESS SEQUENCE
(7 OR 10-BIT ADDRESSING MODE)
SDAx
SCLx
S
SSPxIF
BF (SSPxSTAT<0>)
SSPOV (SSPxCON1<6>)
Cleared in software
SSPxBUF is read
R/W = 0
ACK
General Call Address
Address is Compared to General Call Address
GCEN (SSPxCON2<7>)
Receiving Data ACK
123456789123456789
D7 D6 D5 D4 D3 D2 D1 D0
after ACK, set interrupt
0
1
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 251
PIC18F87J11 FAMILY
19.4.6 MASTER MODE
Master mode is enabled by setting and clearing the
appropriate SSPM bits in SSPxCON1 and by setting
the SSPEN bit. In Master mode, the SCLx and SDAx
lines are manipulated by the MSSP hardware if the
TRIS bits are set.
Master mode of operation is supported by interrupt
generation on the detection of the Start and Stop
conditions. The Stop (P) and Start (S) bits are cleared
from a Reset or when the MSSP module is disabled.
Control of the I2C bus may be taken when the P bit is
set, or the bus is Idle, with both the S and P bits clear.
In Firmware Controlled Master mode, user code
conducts all I2C bus operations based on Start and
Stop bit conditions.
Once Master mode is enabled, the user has six
options.
1. Assert a Start condition on SDAx and SCLx.
2. Assert a Repeated Start condition on SDAx and
SCLx.
3. Write to the SSPxBUF register initiating
transmission of data/address.
4. Configure the I2C port to receive data.
5. Generate an Acknowledge condition at the end
of a received byte of data.
6. Generate a Stop condition on SDAx and SCLx.
The following events will cause the MSSP Interrupt
Flag bit, SSPxIF, to be set (and MSSP interrupt, if
enabled):
Start condition
Stop condition
Data transfer byte transmitted/received
Acknowledge transmitted
Repeated Start
FIGURE 19-18: MSSP BLOCK DIAGRAM (I2C™ MASTER MODE)
Note: The MSSP module, when configured in
I2C Master mode, does not allow queueing
of events. For instance, the user is not
allowed to initiate a Start condition and
immediately write the SSPxBUF register to
initiate transmission before the Start
condition is complete. In this case, the
SSPxBUF will not be written to and the
WCOL bit will be set, indicating that a write
to the SSPxBUF did not occur.
Read Write
SSPxSR
Start bit, Stop bit,
SSPxBUF
Internal
Data Bus
Set/Reset S, P (SSPxSTAT), WCOL (SSPxCON1);
Shift
Clock
MSb LSb
SDAx
Acknowledge
Generate
Stop bit Detect
Write Collision Detect
Clock Arbitration
State Counter for
End of XMIT/RCV
SCLx
SCLx In
Bus Collision
SDAx In
Receive Enable
Clock Cntl
Clock Arbitrate/WCOL Detect
(hold off clock source)
SSPxADD<6:0>
Baud
Set SSPxIF, BCLxIF;
Reset ACKSTAT, PEN (SSPxCON2)
Rate
Generator
SSPM3:SSPM0
Start bit Detect
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DS39778C-page 252 Preliminary © 2008 Microchip Technology Inc.
19.4.6.1 I2C Master Mode Operation
The master device generates all of the serial clock
pulses and the Start and Stop conditions. A transfer is
ended with a Stop condition or with a Repeated Start
condition. Since the Repeated Start condition is also
the beginning of the next serial transfer, the I2C bus will
not be released.
In Master Transmitter mode, serial data is output
through SDAx while SCLx outputs the serial clock. The
first byte transmitted contains the slave address of the
receiving device (7 bits) and the Read/Write (R/W) bit.
In this case, the R/W bit will be logic ‘0’. Serial data is
transmitted 8 bits at a time. After each byte is transmit-
ted, an Acknowledge bit is received. Start and Stop
conditions are output to indicate the beginning and the
end of a serial transfer.
In Master Receive mode, the first byte transmitted
contains the slave address of the transmitting device
(7 bits) and the R/W bit. In this case, the R/W bit will be
logic ‘1’. Thus, the first byte transmitted is a 7-bit slave
address, followed by a ‘1’ to indicate the receive bit.
Serial data is received via SDAx, while SCLx outputs
the serial clock. Serial data is received 8 bits at a time.
After each byte is received, an Acknowledge bit is
transmitted. Start and Stop conditions indicate the
beginning and end of transmission.
The Baud Rate Generator, used for the SPI mode
operation, is used to set the SCLx clock frequency for
either 100 kHz, 400 kHz or 1 MHz I2C operation. See
Section 19.4.7 “Baud Rate for more details.
A typical transmit sequence would go as follows:
1. The user generates a Start condition by setting
the Start Enable bit, SEN (SSPxCON2<0>).
2. SSPxIF is set. The MSSP module will wait the
required start time before any other operation
takes place.
3. The user loads the SSPxBUF with the slave
address to transmit.
4. Address is shifted out the SDAx pin until all 8 bits
are transmitted.
5. The MSSP module shifts in the ACK bit from the
slave device and writes its value into the
SSPxCON2 register (SSPxCON2<6>).
6. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the
SSPxIF bit.
7. The user loads the SSPxBUF with eight bits of
data.
8. Data is shifted out the SDAx pin until all 8 bits
are transmitted.
9. The MSSP module shifts in the ACK bit from the
slave device and writes its value into the
SSPxCON2 register (SSPxCON2<6>).
10. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the
SSPxIF bit.
11. The user generates a Stop condition by setting
the Stop Enable bit, PEN (SSPxCON2<2>).
12. Interrupt is generated once the Stop condition is
complete.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 253
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19.4.7 BAUD RATE
In I2C Master mode, the Baud Rate Generator (BRG)
reload value is placed in the lower 7 bits of the
SSPxADD register (Figure 19-19). When a write
occurs to SSPxBUF, the Baud Rate Generator will
automatically begin counting. The BRG counts down to
0 and stops until another reload has taken place. The
BRG count is decremented twice per instruction cycle
(T
CY) on the Q2 and Q4 clocks. In I2C Master mode, the
BRG is reloaded automatically.
Once the given operation is complete (i.e., transmis-
sion of the last data bit is followed by ACK), the internal
clock will automatically stop counting and the SCLx pin
will remain in its last state.
Table 19-3 demonstrates clock rates based on
instruction cycles and the BRG value loaded into
SSPxADD.
19.4.7.1 Baud Rate and Module
Interdependence
Because MSSP1 and MSSP2 are independent, they
can operate simultaneously in I2C Master mode at
different baud rates. This is done by using different
BRG reload values for each module.
Because this mode derives its basic clock source from
the system clock, any changes to the clock will affect
both modules in the same proportion. It may be
possible to change one or both baud rates back to a
previous value by changing the BRG reload value.
FIGURE 19-19: BAUD RATE GENERATOR BLOCK DIAGRAM
TABLE 19-3: I2C™ CLOCK RATE w/BRG
SSPM3:SSPM0
BRG Down Counter
CLKO FOSC/4
SSPxADD<6:0>
SSPM3:SSPM0
SCLx
Reload
Control
Reload
FOSC FCY FCY * 2 BRG Value FSCL
(2 Rollovers of BRG)
40 MHz 10 MHz 20 MHz 18h 400 kHz(1)
40 MHz 10 MHz 20 MHz 1Fh 312.5 kHz
40 MHz 10 MHz 20 MHz 63h 100 kHz
16 MHz 4 MHz 8 MHz 09h 400 kHz(1)
16 MHz 4 MHz 8 MHz 0Ch 308 kHz
16 MHz 4 MHz 8 MHz 27h 100 kHz
4 MHz 1 MHz 2 MHz 02h 333 kHz(1)
4 MHz 1 MHz 2 MHz 09h 100 kHz
4 MHz 1 MHz 2 MHz 00h 1 MHz(1)
Note 1: The I2C interface does not conform to the 400 kHz I2C specification (which applies to rates greater than
100 kHz) in all details, but may be used with care where higher rates are required by the application.
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DS39778C-page 254 Preliminary © 2008 Microchip Technology Inc.
19.4.7.2 Clock Arbitration
Clock arbitration occurs when the master, during any
receive, transmit or Repeated Start/Stop condition,
deasserts the SCLx pin (SCLx allowed to float high).
When the SCLx pin is allowed to float high, the Baud
Rate Generator (BRG) is suspended from counting
until the SCLx pin is actually sampled high. When the
SCLx pin is sampled high, the Baud Rate Generator is
reloaded with the contents of SSPxADD<6:0> and
begins counting. This ensures that the SCLx high time
will always be at least one BRG rollover count in the
event that the clock is held low by an external device
(Figure 19-20).
FIGURE 19-20: BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
SDAx
SCLx
SCLx deasserted but slave holds
DX – 1DX
BRG
SCLx is sampled high, reload takes
place and BRG starts its count
03h 02h 01h 00h (hold off) 03h 02h
Reload
BRG
Value
SCLx low (clock arbitration)
SCLx allowed to transition high
BRG decrements on
Q2 and Q4 cycles
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 255
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19.4.8 I2C MASTER MODE START
CONDITION TIMING
To initiate a Start condition, the user sets the Start
Enable bit, SEN (SSPxCON2<0>). If the SDAx and
SCLx pins are sampled high, the Baud Rate Generator
is reloaded with the contents of SSPxADD<6:0> and
starts its count. If SCLx and SDAx are both sampled
high when the Baud Rate Generator times out (TBRG),
the SDAx pin is driven low. The action of the SDAx
being driven low while SCLx is high is the Start condi-
tion and causes the S bit (SSPxSTAT<3>) to be set.
Following this, the Baud Rate Generator is reloaded
with the contents of SSPxADD<6:0> and resumes its
count. When the Baud Rate Generator times out
(TBRG), the SEN bit (SSPxCON2<0>) will be
automatically cleared by hardware. The Baud Rate
Generator is suspended, leaving the SDAx line held low
and the Start condition is complete.
19.4.8.1 WCOL Status Flag
If the user writes the SSPxBUF when a Start sequence
is in progress, the WCOL bit is set and the contents of
the buffer are unchanged (the write doesn’t occur).
FIGURE 19-21: FIRST START BIT TIMING
Note: If, at the beginning of the Start condition,
the SDAx and SCLx pins are already sam-
pled low or if during the Start condition, the
SCLx line is sampled low before the SDAx
line is driven low, a bus collision occurs,
the Bus Collision Interrupt Flag, BCLxIF, is
set, the Start condition is aborted and the
I2C module is reset into its Idle state.
Note: Because queueing of events is not
allowed, writing to the lower 5 bits of
SSPxCON2 is disabled until the Start
condition is complete.
SDAx
SCLx
S
TBRG
1st bit 2nd bit
TBRG
SDAx = 1, At completion of Start bit,
SCLx = 1
Write to SSPxBUF occurs here
TBRG
hardware clears SEN bit
TBRG
Write to SEN bit occurs here Set S bit (SSPxSTAT<3>)
and sets SSPxIF bit
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DS39778C-page 256 Preliminary © 2008 Microchip Technology Inc.
19.4.9 I2C MASTER MODE REPEATED
START CONDITION TIMING
A Repeated Start condition occurs when the RSEN bit
(SSPxCON2<1>) is programmed high and the I2C logic
module is in the Idle state. When the RSEN bit is set,
the SCLx pin is asserted low. When the SCLx pin is
sampled low, the Baud Rate Generator is loaded with
the contents of SSPxADD<5:0> and begins counting.
The SDAx pin is released (brought high) for one Baud
Rate Generator count (TBRG). When the Baud Rate
Generator times out and if SDAx is sampled high, the
SCLx pin will be deasserted (brought high). When
SCLx is sampled high, the Baud Rate Generator is
reloaded with the contents of SSPxADD<6:0> and
begins counting. SDAx and SCLx must be sampled
high for one TBRG. This action is then followed by
assertion of the SDAx pin (SDAx = 0) for one TBRG
while SCLx is high. Following this, the RSEN bit
(SSPxCON2<1>) will be automatically cleared and the
Baud Rate Generator will not be reloaded, leaving the
SDAx pin held low. As soon as a Start condition is
detected on the SDAx and SCLx pins, the S bit
(SSPxSTAT<3>) will be set. The SSPxIF bit will not be
set until the Baud Rate Generator has timed out.
Immediately following the SSPxIF bit getting set, the
user may write the SSPxBUF with the 7-bit address in
7-bit mode, or the default first address in 10-bit mode.
After the first eight bits are transmitted and an ACK is
received, the user may then transmit an additional eight
bits of address (10-bit mode) or eight bits of data (7-bit
mode).
19.4.9.1 WCOL Status Flag
If the user writes the SSPxBUF when a Repeated Start
sequence is in progress, the WCOL is set and the
contents of the buffer are unchanged (the write doesn’t
occur).
FIGURE 19-22: REPEATED START CONDITION WAVEFORM
Note 1: If RSEN is programmed while any other
event is in progress, it will not take effect.
2: A bus collision during the Repeated Start
condition occurs if:
SDAx is sampled low when SCLx
goes from low-to-high.
SCLx goes low before SDAx is
asserted low. This may indicate that
another master is attempting to
transmit a data ‘1’.
Note: Because queueing of events is not
allowed, writing of the lower 5 bits of
SSPxCON2 is disabled until the Repeated
Start condition is complete.
SDAx
SCLx
Sr = Repeated Start
Write to SSPxCON2
Write to SSPxBUF occurs here
on falling edge of ninth clock,
end of XMIT
At completion of Start bit,
hardware clears RSEN bit
1st bit
S bit set by hardware
TBRG
SDAx = 1,
SDAx = 1,
SCLx (no change).
SCLx = 1
occurs here:
and sets SSPxIF
RSEN bit set by hardware
TBRG
TBRG TBRG TBRG
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 257
PIC18F87J11 FAMILY
19.4.10 I2C MASTER MODE TRANSMISSION
Transmission of a data byte, a 7-bit address or the
other half of a 10-bit address, is accomplished by sim-
ply writing a value to the SSPxBUF register. This action
will set the Buffer Full flag bit, BF, and allow the Baud
Rate Generator to begin counting and start the next
transmission. Each bit of address/data will be shifted
out onto the SDAx pin after the falling edge of SCLx is
asserted (see data hold time specification
parameter 106). SCLx is held low for one Baud Rate
Generator rollover count (TBRG). Data should be valid
before SCLx is released high (see data setup time
specification parameter 107). When the SCLx pin is
released high, it is held that way for TBRG. The data on
the SDAx pin must remain stable for that duration and
some hold time after the next falling edge of SCLx.
After the eighth bit is shifted out (the falling edge of the
eighth clock), the BF flag is cleared and the master
releases SDAx. This allows the slave device being
addressed to respond with an ACK bit during the ninth
bit time if an address match occurred, or if data was
received properly. The status of ACK is written into the
ACKDT bit on the falling edge of the ninth clock. If the
master receives an Acknowledge, the Acknowledge
Status bit, ACKSTAT, is cleared; if not, the bit is set.
After the ninth clock, the SSPxIF bit is set and the
master clock (Baud Rate Generator) is suspended until
the next data byte is loaded into the SSPxBUF, leaving
SCLx low and SDAx unchanged (Figure 19-23).
After the write to the SSPxBUF, each bit of the address
will be shifted out on the falling edge of SCLx until all
seven address bits and the R/W bit are completed. On
the falling edge of the eighth clock, the master will
deassert the SDAx pin, allowing the slave to respond
with an Acknowledge. On the falling edge of the ninth
clock, the master will sample the SDAx pin to see if the
address was recognized by a slave. The status of the
ACK bit is loaded into the ACKSTAT status bit
(SSPxCON2<6>). Following the falling edge of the
ninth clock transmission of the address, the SSPxIF
flag is set, the BF flag is cleared and the Baud Rate
Generator is turned off until another write to the
SSPxBUF takes place, holding SCLx low and allowing
SDAx to float.
19.4.10.1 BF Status Flag
In Transmit mode, the BF bit (SSPxSTAT<0>) is set
when the CPU writes to SSPxBUF and is cleared when
all 8 bits are shifted out.
19.4.10.2 WCOL Status Flag
If the user writes the SSPxBUF when a transmit is
already in progress (i.e., SSPxSR is still shifting out a
data byte), the WCOL bit is set and the contents of the
buffer are unchanged (the write doesn’t occur) after
2T
CY after the SSPxBUF write. If SSPxBUF is rewritten
within 2 TCY, the WCOL bit is set and SSPxBUF is
updated. This may result in a corrupted transfer.
The user should verify that the WCOL bit is clear after
each write to SSPxBUF to ensure the transfer is correct.
In all cases, WCOL must be cleared in software.
19.4.10.3 ACKSTAT Status Flag
In Transmit mode, the ACKSTAT bit (SSPxCON2<6>)
is cleared when the slave has sent an Acknowledge
(ACK =0) and is set when the slave does not Acknowl-
edge (ACK = 1). A slave sends an Acknowledge when
it has recognized its address (including a general call),
or when the slave has properly received its data.
19.4.11 I2C MASTER MODE RECEPTION
Master mode reception is enabled by programming the
Receive Enable bit, RCEN (SSPxCON2<3>).
The Baud Rate Generator begins counting and on each
rollover, the state of the SCLx pin changes
(high-to-low/low-to-high) and data is shifted into the
SSPxSR. After the falling edge of the eighth clock, the
receive enable flag is automatically cleared, the con-
tents of the SSPxSR are loaded into the SSPxBUF, the
BF flag bit is set, the SSPxIF flag bit is set and the Baud
Rate Generator is suspended from counting, holding
SCLx low. The MSSP is now in Idle state awaiting the
next command. When the buffer is read by the CPU,
the BF flag bit is automatically cleared. The user can
then send an Acknowledge bit at the end of reception
by setting the Acknowledge Sequence Enable bit,
ACKEN (SSPxCON2<4>).
19.4.11.1 BF Status Flag
In receive operation, the BF bit is set when an address
or data byte is loaded into SSPxBUF from SSPxSR. It
is cleared when the SSPxBUF register is read.
19.4.11.2 SSPOV Status Flag
In receive operation, the SSPOV bit is set when 8 bits
are received into the SSPxSR and the BF flag bit is
already set from a previous reception.
19.4.11.3 WCOL Status Flag
If the user writes the SSPxBUF when a receive is
already in progress (i.e., SSPxSR is still shifting in a
data byte), the WCOL bit is set and the contents of the
buffer are unchanged (the write doesn’t occur).
Note: The MSSP module must be in an inactive
state before the RCEN bit is set or the
RCEN bit will be disregarded.
PIC18F87J11 FAMILY
DS39778C-page 258 Preliminary © 2008 Microchip Technology Inc.
FIGURE 19-23: I2C™ MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS)
SDAx
SCLx
SSPxIF
BF (SSPxSTAT<0>)
SEN
A7 A6 A5 A4 A3 A2 A1 ACK = 0D7 D6 D5 D4 D3 D2 D1 D0
ACK
Transmitting Data or Second Half
R/W = 0Transmit Address to Slave
123456789 123456789 P
Cleared in software service routine
SSPxBUF is written in software
from MSSP interrupt
After Start condition, SEN cleared by hardware
S
SSPxBUF written with 7-bit address and R/W,
start transmit
SCLx held low
while CPU
responds to SSPxIF
SEN = 0
of 10-bit Address
Write SSPxCON2<0> (SEN = 1),
Start condition begins From slave, clear ACKSTAT bit (SSPxCON2<6>)
ACKSTAT in
SSPxCON2 = 1
Cleared in software
SSPxBUF written
PEN
R/W
Cleared in software
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 259
PIC18F87J11 FAMILY
FIGURE 19-24: I2C™ MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)
P
9
87
6
5
D0
D1
D2
D3D4
D5
D6D7
S
A7 A6 A5 A4 A3 A2 A1
SDAx
SCLx 12
345678912345678 9 1234
Bus master
terminates
transfer
ACK
Receiving Data from Slave
Receiving Data from Slave
D0
D1
D2
D3D4
D5
D6D7
ACK
R/W = 0
Transmit Address to Slave
SSPxIF
BF
ACK is not sent
Write to SSPxCON2<0> (SEN = 1),
Write to SSPxBUF occurs here, ACK from Slave
Master configured as a receiver
by programming SSPxCON2<3> (RCEN = 1)
PEN bit = 1
written here
Data shifted in on falling edge of CLK
Cleared in software
start XMIT
SEN = 0
SSPOV
SDAx = 0, SCLx = 1,
while CPU
(SSPxSTAT<0>)
ACK
Cleared in software
Cleared in software
Set SSPxIF interrupt
at end of receive
Set P bit
(SSPxSTAT<4>)
and SSPxIF
ACK from master,
Set SSPxIF at end
Set SSPxIF interrupt
at end of Acknowledge
sequence
Set SSPxIF interrupt
at end of Acknowledge
sequence
of receive
Set ACKEN, start Acknowledge sequence,
SDAx = ACKDT = 1
RCEN cleared
automatically
RCEN = 1, start
next receive
Write to SSPxCON2<4>
to start Acknowledge sequence,
SDAx = ACKDT (SSPxCON2<5>) = 0
RCEN cleared
automatically
responds to SSPxIF
ACKEN
begin Start condition
Cleared in software
SDAx = ACKDT = 0
Last bit is shifted into SSPxSR and
contents are unloaded into SSPxBUF
Cleared in
software
SSPOV is set because
SSPxBUF is still full
PIC18F87J11 FAMILY
DS39778C-page 260 Preliminary © 2008 Microchip Technology Inc.
19.4.12 ACKNOWLEDGE SEQUENCE
TIMING
An Acknowledge sequence is enabled by setting the
Acknowledge Sequence Enable bit, ACKEN
(SSPxCON2<4>). When this bit is set, the SCLx pin is
pulled low and the contents of the Acknowledge data bit
are presented on the SDAx pin. If the user wishes to
generate an Acknowledge, then the ACKDT bit should
be cleared. If not, the user should set the ACKDT bit
before starting an Acknowledge sequence. The Baud
Rate Generator then counts for one rollover period
(TBRG) and the SCLx pin is deasserted (pulled high).
When the SCLx pin is sampled high (clock arbitration),
the Baud Rate Generator counts for TBRG; the SCLx pin
is then pulled low. Following this, the ACKEN bit is auto-
matically cleared, the Baud Rate Generator is turned off
and the MSSP module then goes into an inactive state
(Figure 19-25).
19.4.12.1 WCOL Status Flag
If the user writes the SSPxBUF when an Acknowledge
sequence is in progress, then WCOL is set and the
contents of the buffer are unchanged (the write doesn’t
occur).
19.4.13 STOP CONDITION TIMING
A Stop bit is asserted on the SDAx pin at the end of a
receive/transmit by setting the Stop Sequence Enable
bit, PEN (SSPxCON2<2>). At the end of a
receive/transmit, the SCLx line is held low after the
falling edge of the ninth clock. When the PEN bit is set,
the master will assert the SDAx line low. When the
SDAx line is sampled low, the Baud Rate Generator is
reloaded and counts down to 0. When the Baud Rate
Generator times out, the SCLx pin will be brought high
and one TBRG (Baud Rate Generator rollover count)
later, the SDAx pin will be deasserted. When the SDAx
pin is sampled high while SCLx is high, the P bit
(SSPxSTAT<4>) is set. A TBRG later, the PEN bit is
cleared and the SSPxIF bit is set (Figure 19-26).
19.4.13.1 WCOL Status Flag
If the user writes the SSPxBUF when a Stop sequence
is in progress, then the WCOL bit is set and the
contents of the buffer are unchanged (the write doesn’t
occur).
FIGURE 19-25: ACKNOWLEDGE SEQUENCE WAVEFORM
Note: TBRG = one Baud Rate Generator period.
SDAx
SCLx
SSPxIF set at
Acknowledge sequence starts here,
write to SSPxCON2, ACKEN automatically cleared
Cleared in
TBRG TBRG
the end of receive
8
ACKEN = 1, ACKDT = 0
D0
9
SSPxIF
software SSPxIF set at the end
of Acknowledge sequence
Cleared in
software
ACK
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 261
PIC18F87J11 FAMILY
FIGURE 19-26: STOP CONDITION RECEIVE OR TRANSMIT MODE
19.4.14 SLEEP OPERATION
While in Sleep mode, the I2C module can receive
addresses or data and when an address match or
complete byte transfer occurs, wake the processor
from Sleep (if the MSSP interrupt is enabled).
19.4.15 EFFECTS OF A RESET
A Reset disables the MSSP module and terminates the
current transfer.
19.4.16 MULTI-MASTER MODE
In Multi-Master mode, the interrupt generation on the
detection of the Start and Stop conditions allows the
determination of when the bus is free. The Stop (P) and
Start (S) bits are cleared from a Reset or when the
MSSP module is disabled. Control of the I2C bus may
be taken when the P bit (SSPxSTAT<4>) is set, or the
bus is Idle, with both the S and P bits clear. When the
bus is busy, enabling the MSSP interrupt will generate
the interrupt when the Stop condition occurs.
In multi-master operation, the SDAx line must be
monitored for arbitration to see if the signal level is the
expected output level. This check is performed in
hardware with the result placed in the BCLxIF bit.
The states where arbitration can be lost are:
Address Transfer
Data Transfer
A Start Condition
A Repeated Start Condition
An Acknowledge Condition
19.4.17 MULTI -MASTER COMMUNICATION,
BUS COLLISION AND BUS
ARBITRATION
Multi-Master mode support is achieved by bus arbitra-
tion. When the master outputs address/data bits onto
the SDAx pin, arbitration takes place when the master
outputs a ‘1’ on SDAx, by letting SDAx float high, and
another master asserts a ‘0’. When the SCLx pin floats
high, data should be stable. If the expected data on
SDAx is a ‘1’ and the data sampled on the SDAx
pin = 0, then a bus collision has taken place. The
master will set the Bus Collision Interrupt Flag, BCLxIF
and reset the I2C port to its Idle state (Figure 19-27).
If a transmit was in progress when the bus collision
occurred, the transmission is halted, the BF flag is
cleared, the SDAx and SCLx lines are deasserted and
the SSPxBUF can be written to. When the user services
the bus collision Interrupt Service Routine and if the I2C
bus is free, the user can resume communication by
asserting a Start condition.
If a Start, Repeated Start, Stop or Acknowledge condition
was in progress when the bus collision occurred, the con-
dition is aborted, the SDAx and SCLx lines are
deasserted and the respective control bits in the
SSPxCON2 register are cleared. When the user services
the bus collision Interrupt Service Routine, and if the I2C
bus is free, the user can resume communication by
asserting a Start condition.
The master will continue to monitor the SDAx and SCLx
pins. If a Stop condition occurs, the SSPxIF bit will be set.
A write to the SSPxBUF will start the transmission of
data at the first data bit regardless of where the
transmitter left off when the bus collision occurred.
In Multi-Master mode, the interrupt generation on the
detection of Start and Stop conditions allows the determi-
nation of when the bus is free. Control of the I2C bus can
be taken when the P bit is set in the SSPxSTAT register,
or the bus is Idle and the S and P bits are cleared.
SCLx
SDAx
SDAx asserted low before rising edge of clock
Write to SSPxCON2,
set PEN
Falling edge of
SCLx = 1 for TBRG, followed by SDAx = 1 for TBRG
9th clock
SCLx brought high after TBRG
Note: TBRG = one Baud Rate Generator period.
TBRG TBRG
after SDAx sampled high. P bit (SSPxSTAT<4>) is set
TBRG
to set up Stop condition
ACK
P
TBRG
PEN bit (SSPxCON2<2>) is cleared by
hardware and the SSPxIF bit is set
PIC18F87J11 FAMILY
DS39778C-page 262 Preliminary © 2008 Microchip Technology Inc.
FIGURE 19-27: BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE
SDAx
SCLx
BCLxIF
SDAx released
SDAx line pulled low
by another source
Sample SDAx. While SCLx is high,
data doesn’t match what is driven
bus collision has occurred.
Set bus collision
interrupt (BCLxIF)
by the master;
by master
Data changes
while SCLx = 0
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 263
PIC18F87J11 FAMILY
19.4.17.1 Bus Collision During a Start
Condition
During a Start condition, a bus collision occurs if:
a) SDAx or SCLx is sampled low at the beginning
of the Start condition (Figure 19-28).
b) SCLx is sampled low before SDAx is asserted
low (Figure 19-29).
During a Start condition, both the SDAx and the SCLx
pins are monitored.
If the SDAx pin is already low, or the SCLx pin is
already low, then all of the following occur:
the Start condition is aborted,
the BCLxIF flag is set and
the MSSP module is reset to its inactive state
(Figure 19-28)
The Start condition begins with the SDAx and SCLx
pins deasserted. When the SDAx pin is sampled high,
the Baud Rate Generator is loaded from
SSPxADD<6:0> and counts down to 0. If the SCLx pin
is sampled low while SDAx is high, a bus collision
occurs because it is assumed that another master is
attempting to drive a data ‘1 during the Start condition.
If the SDAx pin is sampled low during this count, the
BRG is reset and the SDAx line is asserted early
(Figure 19-30). If, however, a ‘1’ is sampled on the
SDAx pin, the SDAx pin is asserted low at the end of
the BRG count. The Baud Rate Generator is then
reloaded and counts down to 0. If the SCLx pin is
sampled as ‘0’ during this time, a bus collision does not
occur. At the end of the BRG count, the SCLx pin is
asserted low.
FIGURE 19-28: BUS COLLISION DURING START CONDITION (SDAx ONLY)
Note: The reason that bus collision is not a factor
during a Start condition is that no two bus
masters can assert a Start condition at the
exact same time. Therefore, one master
will always assert SDAx before the other.
This condition does not cause a bus colli-
sion because the two masters must be
allowed to arbitrate the first address
following the Start condition. If the address
is the same, arbitration must be allowed to
continue into the data portion, Repeated
Start or Stop conditions.
SDAx
SCLx
SEN
SDAx sampled low before
SDAx goes low before the SEN bit is set.
S bit and SSPxIF set because
MSSP module reset into Idle state.
SEN cleared automatically because of bus collision.
S bit and SSPxIF set because
Set SEN, enable Start
condition if SDAx = 1, SCLx = 1
SDAx = 0, SCLx = 1.
BCLxIF
S
SSPxIF
SDAx = 0, SCLx = 1.
SSPxIF and BCLxIF are
cleared in software
SSPxIF and BCLxIF are
cleared in software
Set BCLxIF,
Start condition. Set BCLxIF.
PIC18F87J11 FAMILY
DS39778C-page 264 Preliminary © 2008 Microchip Technology Inc.
FIGURE 19-29: BUS COLLISION DURING START CONDITION (SCLx = 0)
FIGURE 19-30: BRG RESET DUE TO SDAx ARBITRATION DURING START CONDITION
SDAx
SCLx
SEN bus collision occurs. Set BCLxIF.
SCLx = 0 before SDAx = 0,
Set SEN, enable Start
sequence if SDAx = 1, SCLx = 1
TBRG TBRG
SDAx = 0, SCLx = 1
BCLxIF
S
SSPxIF
Interrupt cleared
in software
bus collision occurs. Set BCLxIF.
SCLx = 0 before BRG time-out,
0’‘0
00
SDAx
SCLx
SEN
Set S
Less than TBRG TBRG
SDAx = 0, SCLx = 1
BCLxIF
S
SSPxIF
S
Interrupts cleared
in software
set SSPxIF
SDAx = 0, SCLx = 1,
SCLx pulled low after BRG
time-out
Set SSPxIF
0
SDAx pulled low by other master.
Reset BRG and assert SDAx.
Set SEN, enable Start
sequence if SDAx = 1, SCLx = 1
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 265
PIC18F87J11 FAMILY
19.4.17.2 Bus Collision During a Repeated
Start Condition
During a Repeated Start condition, a bus collision
occurs if:
a) A low level is sampled on SDAx when SCLx
goes from a low level to a high level.
b) SCLx goes low before SDAx is asserted low,
indicating that another master is attempting to
transmit a data ‘1’.
When the user deasserts SDAx and the pin is allowed
to float high, the BRG is loaded with SSPxADD<6:0>
and counts down to 0. The SCLx pin is then deasserted
and when sampled high, the SDAx pin is sampled.
If SDAx is low, a bus collision has occurred (i.e., another
master is attempting to transmit a data ‘0’,
Figure 19-31). If SDAx is sampled high, the BRG is
reloaded and begins counting. If SDAx goes from
high-to-low before the BRG times out, no bus collision
occurs because no two masters can assert SDAx at
exactly the same time.
If SCLx goes from high-to-low before the BRG times
out and SDAx has not already been asserted, a bus
collision occurs. In this case, another master is
attempting to transmit a data ‘1’ during the Repeated
Start condition (see Figure 19-32).
If, at the end of the BRG time-out, both SCLx and SDAx
are still high, the SDAx pin is driven low and the BRG is
reloaded and begins counting. At the end of the count,
regardless of the status of the SCLx pin, the SCLx pin is
driven low and the Repeated Start condition is complete.
FIGURE 19-31: BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)
SDAx
SCLx
RSEN
BCLxIF
S
SSPxIF
Sample SDAx when SCLx goes high.
If SDAx = 0, set BCLxIF and release SDAx and SCLx.
Cleared in software
0
0
PIC18F87J11 FAMILY
DS39778C-page 266 Preliminary © 2008 Microchip Technology Inc.
FIGURE 19-32: BUS COLLISION DURING REPEATED START CONDITION (CASE 2)
SDAx
SCLx
BCLxIF
RSEN
S
SSPxIF
Interrupt cleared
in software
SCLx goes low before SDAx,
set BCLxIF. Release SDAx and SCLx.
TBRG TBRG
0
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 267
PIC18F87J11 FAMILY
19.4.17.3 Bus Collision During a Stop
Condition
Bus collision occurs during a Stop condition if:
a) After the SDAx pin has been deasserted and
allowed to float high, SDAx is sampled low after
the BRG has timed out.
b) After the SCLx pin is deasserted, SCLx is
sampled low before SDAx goes high.
The Stop condition begins with SDAx asserted low.
When SDAx is sampled low, the SCLx pin is allowed to
float. When the pin is sampled high (clock arbitration),
the Baud Rate Generator is loaded with
SSPxADD<6:0> and counts down to 0. After the BRG
times out, SDAx is sampled. If SDAx is sampled low, a
bus collision has occurred. This is due to another
master attempting to drive a data ‘0’ (Figure 19-33). If
the SCLx pin is sampled low before SDAx is allowed to
float high, a bus collision occurs. This is another case
of another master attempting to drive a data ‘0
(Figure 19-34).
FIGURE 19-33: BUS COLLISION DURING A STOP CONDITION (CASE 1)
FIGURE 19-34: BUS COLLISION DURING A STOP CONDITION (CASE 2)
SDAx
SCLx
BCLxIF
PEN
P
SSPxIF
TBRG TBRG TBRG
SDAx asserted low
SDAx sampled
low after TBRG,
set BCLxIF
0
0
SDAx
SCLx
BCLxIF
PEN
P
SSPxIF
TBRG TBRG TBRG
Assert SDAx SCLx goes low before SDAx goes high,
set BCLxIF
0
0
PIC18F87J11 FAMILY
DS39778C-page 268 Preliminary © 2008 Microchip Technology Inc.
TABLE 19-4: REGISTERS ASSOCIATED WITH I2C™ OPERATION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR2 OSCFIF CM2IF CM1IF —BCL1IFLVDIF TMR3IF CCP2IF 58
PIE2 OSCFIE CM2IE CM1IE —BCL1IELVDIE TMR3IE CCP2IE 58
IPR2 OSCFIP CM2IP CM1IP —BCL1IPLVDIP TMR3IP CCP2IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 58
TRISD TRISD7 TRISD6 TRISD5 TRISD4 TRISD3 TRISD2 TRISD1 TRISD0 58
SSP1BUF MSSP1 Receive Buffer/Transmit Register 56
SSP1ADD MSSP1 Address Register (I2C™ Slave mode),
MSSP1 Baud Rate Reload Register (I2C Master mode)
56
SSP1MSK(1) MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0 56
SSP1CON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 56
SSP1CON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 56
GCEN ACKSTAT ADMSK5(2) ADMSK4(2) ADMSK3(2) ADMSK2(2) ADMSK1(2) SEN
SSP1STAT SMP CKE D/A PSR/WUA BF 56
SSP2BUF MSSP2 Receive Buffer/Transmit Register 59
SSP2ADD MSSP2 Address Register (I2C Slave mode),
MSSP2 Baud Rate Reload Register (I2C Master mode)
59
SSP2MSK(1) MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0 59
SSP2CON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 59
SSP2CON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 59
GCEN ACKSTAT ADMSK5(2) ADMSK4(2) ADMSK3(2) ADMSK2(2) ADMSK1(2) SEN
SSP2STAT SMP CKE D/A PSR/WUA BF 59
Legend: = unimplemented, read as ‘0’. Shaded cells are not used by the MSSP module in I2C™ mode.
Note 1: SSPxMSK shares the same address in SFR space as SSPxADD, but is only accessible in certain I2C™
Slave operating modes in 7-bit Masking mode. See Section 19.4.3.4 “7-Bit Address Masking Mode” for
more details.
2: Alternate bit definitions for use in I2C Slave mode operations only.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 269
PIC18F87J11 FAMILY
20.0 ENHANCED UNIVERSAL
SYNCHRONOUS
ASYNCHRONOUS RECEIVER
TRANSMITTER (EUSART)
The Enhanced Universal Synchronous Asynchronous
Receiver Transmitter (EUSART) module is one of two
serial I/O modules. (Generically, the EUSART is also
known as a Serial Communications Interface or SCI.)
The EUSART can be configured as a full-duplex
asynchronous system that can communicate with
peripheral devices, such as CRT terminals and
personal computers. It can also be configured as a
half-duplex synchronous system that can communicate
with peripheral devices, such as A/D or D/A integrated
circuits, serial EEPROMs, etc.
The Enhanced USART module implements additional
features, including automatic baud rate detection and
calibration, automatic wake-up on Sync Break recep-
tion and 12-bit Break character transmit. These make it
ideally suited for use in Local Interconnect Network bus
(LIN bus) systems.
All members of the PIC18F87J11 family are equipped
with two independent EUSART modules, referred to as
EUSART1 and EUSART2. They can be configured in
the following modes:
Asynchronous (full duplex) with:
- Auto-wake-up on character reception
- Auto-baud calibration
- 12-bit Break character transmission
Synchronous – Master (half duplex) with
selectable clock polarity
Synchronous – Slave (half duplex) with selectable
clock polarity
The pins of EUSART1 and EUSART2 are multiplexed
with the functions of PORTC (RC6/TX1/CK1 and
RC7/RX1/DT1) and PORTG (RG1/TX2/CK2 and
RG2/RX2/DT2), respectively. In order to configure
these pins as an EUSART:
For EUSART1:
- bit SPEN (RCSTA1<7>) must be set (= 1)
- bit TRISC<7> must be set (= 1)
- bit TRISC<6> must be cleared (= 0) for
Asynchronous and Synchronous Master
modes
- bit TRISC<6> must be set (= 1) for
Synchronous Slave mode
For EUSART2:
- bit SPEN (RCSTA2<7>) must be set (= 1)
- bit TRISG<2> must be set (= 1)
- bit TRISG<1> must be cleared (= 0) for
Asynchronous and Synchronous Master
modes
- bit TRISC<6> must be set (= 1) for
Synchronous Slave mode
The operation of each Enhanced USART module is
controlled through three registers:
Transmit Status and Control (TXSTAx)
Receive Status and Control (RCSTAx)
Baud Rate Control (BAUDCONx)
These are detailed on the following pages in
Register 20-1, Register 20-2 and Register 20-3,
respectively.
Note: The EUSART control will automatically
reconfigure the pin from input to output as
needed.
Note: Throughout this section, references to
register and bit names that may be associ-
ated with a specific EUSART module are
referred to generically by the use of ‘x’ in
place of the specific module number.
Thus, “RCSTAx” might refer to the
Receive Status register for either
EUSART1 or EUSART2.
PIC18F87J11 FAMILY
DS39778C-page 270 Preliminary © 2008 Microchip Technology Inc.
REGISTER 20-1: TXSTAx: TRANSMIT STATUS AND CONTROL REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-1 R/W-0
CSRC TX9 TXEN(1) SYNC SENDB BRGH TRMT TX9D
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 CSRC: Clock Source Select bit
Asynchronous mode:
Don’t care.
Synchronous mode:
1 = Master mode (clock generated internally from BRG)
0 = Slave mode (clock from external source)
bit 6 TX9: 9-Bit Transmit Enable bit
1 = Selects 9-bit transmission
0 = Selects 8-bit transmission
bit 5 TXEN: Transmit Enable bit(1)
1 = Transmit enabled
0 = Transmit disabled
bit 4 SYNC: EUSART Mode Select bit
1 = Synchronous mode
0 = Asynchronous mode
bit 3 SENDB: Send Break Character bit
Asynchronous mode:
1 = Send Sync Break on next transmission (cleared by hardware upon completion)
0 = Sync Break transmission completed
Synchronous mode:
Don’t care.
bit 2 BRGH: High Baud Rate Select bit
Asynchronous mode:
1 = High speed
0 = Low speed
Synchronous mode:
Unused in this mode.
bit 1 TRMT: Transmit Shift Register Status bit
1 = TSR empty
0 = TSR full
bit 0 TX9D: 9th bit of Transmit Data
Can be address/data bit or a parity bit.
Note 1: SREN/CREN overrides TXEN in Sync mode.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 271
PIC18F87J11 FAMILY
REGISTER 20-2: RCSTAx: RECEIVE STATUS AND CONTROL REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x
SPEN RX9 SREN CREN ADDEN FERR OERR RX9D
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SPEN: Serial Port Enable bit
1 = Serial port enabled (configures RXx/DTx and TXx/CKx pins as serial port pins)
0 = Serial port disabled (held in Reset)
bit 6 RX9: 9-Bit Receive Enable bit
1 = Selects 9-bit reception
0 = Selects 8-bit reception
bit 5 SREN: Single Receive Enable bit
Asynchronous mode:
Don’t care.
Synchronous mode – Master:
1 = Enables single receive
0 = Disables single receive
This bit is cleared after reception is complete.
Synchronous mode – Slave:
Don’t care.
bit 4 CREN: Continuous Receive Enable bit
Asynchronous mode:
1 = Enables receiver
0 = Disables receiver
Synchronous mode:
1 = Enables continuous receive until enable bit CREN is cleared (CREN overrides SREN)
0 = Disables continuous receive
bit 3 ADDEN: Address Detect Enable bit
Asynchronous mode 9-Bit (RX9 = 1):
1 = Enables address detection, enables interrupt and loads the receive buffer when RSR<8> is set
0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit
Asynchronous mode 9-Bit (RX9 = 0):
Don’t care.
bit 2 FERR: Framing Error bit
1 = Framing error (can be updated by reading RCREGx register and receiving next valid byte)
0 = No framing error
bit 1 OERR: Overrun Error bit
1 = Overrun error (can be cleared by clearing bit CREN)
0 = No overrun error
bit 0 RX9D: 9th bit of Received Data
This can be address/data bit or a parity bit and must be calculated by user firmware.
PIC18F87J11 FAMILY
DS39778C-page 272 Preliminary © 2008 Microchip Technology Inc.
REGISTER 20-3: BAUDCONx: BAUD RATE CONTROL REGISTER
R/W-0 R-1 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0
ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 ABDOVF: Auto-Baud Acquisition Rollover Status bit
1 = A BRG rollover has occurred during Auto-Baud Rate Detect mode
(must be cleared in software)
0 = No BRG rollover has occurred
bit 6 RCIDL: Receive Operation Idle Status bit
1 = Receive operation is Idle
0 = Receive operation is active
bit 5 RXDTP: Data/Receive Polarity Select bit
Asynchronous mode:
1 = Receive data (RXx) is inverted (active-low)
0 = Receive data (RXx) is not inverted (active-high)
Synchronous mode:
1 = Data (DTx) is inverted (active-low)
0 = Data (DTx) is not inverted (active-high)
bit 4 TXCKP: Synchronous Clock Polarity Select bit
Asynchronous mode:
1 = Idle state for transmit (TXx) is a low level
0 = Idle state for transmit (TXx) is a high level
Synchronous mode:
1 = Idle state for clock (CKx) is a high level
0 = Idle state for clock (CKx) is a low level
bit 3 BRG16: 16-Bit Baud Rate Register Enable bit
1 = 16-bit Baud Rate Generator – SPBRGHx and SPBRGx
0 = 8-bit Baud Rate Generator – SPBRGx only (Compatible mode), SPBRGHx value ignored
bit 2 Unimplemented: Read as0
bit 1 WUE: Wake-up Enable bit
Asynchronous mode:
1 = EUSART will continue to sample the RXx pin – interrupt generated on falling edge; bit cleared in
hardware on following rising edge
0 = RXx pin not monitored or rising edge detected
Synchronous mode:
Unused in this mode.
bit 0 ABDEN: Auto-Baud Detect Enable bit
Asynchronous mode:
1 = Enable baud rate measurement on the next character. Requires reception of a Sync field (55h);
cleared in hardware upon completion.
0 = Baud rate measurement disabled or completed
Synchronous mode:
Unused in this mode.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 273
PIC18F87J11 FAMILY
20.1 Baud Rate Generator (BRG)
The BRG is a dedicated, 8-bit or 16-bit generator that
supports both the Asynchronous and Synchronous
modes of the EUSART. By default, the BRG operates
in 8-bit mode; setting the BRG16 bit (BAUDCONx<3>)
selects 16-bit mode.
The SPBRGHx:SPBRGx register pair controls the period
of a free-running timer. In Asynchronous mode, bits
BRGH (TXSTAx<2>) and BRG16 (BAUDCONx<3>) also
control the baud rate. In Synchronous mode, BRGH is
ignored. Table 20-1 shows the formula for computation of
the baud rate for different EUSART modes which only
apply in Master mode (internally generated clock).
Given the desired baud rate and FOSC, the nearest
integer value for the SPBRGHx:SPBRGx registers can
be calculated using the formulas in Table 20-1. From this,
the error in baud rate can be determined. An example
calculation is shown in Example 20-1. Typical baud rates
and error values for the various Asynchronous modes
are shown in Table 20-2. It may be advantageous to use
the high baud rate (BRGH = 1) or the 16-bit BRG to
reduce the baud rate error, or achieve a slow baud rate
for a fast oscillator frequency.
Writing a new value to the SPBRGHx:SPBRGx regis-
ters causes the BRG timer to be reset (or cleared). This
ensures the BRG does not wait for a timer overflow
before outputting the new baud rate.
20.1.1 OPERATION IN POWER-MANAGED
MODES
The device clock is used to generate the desired baud
rate. When one of the power-managed modes is
entered, the new clock source may be operating at a
different frequency. This may require an adjustment to
the value in the SPBRGx register pair.
20.1.2 SAMPLING
The data on the RXx pin (either RC7/RX1/DT1 or
RG2/RX2/DT2) is sampled three times by a majority
detect circuit to determine if a high or a low level is
present at the RXx pin.
TABLE 20-1: BAUD RATE FORMULAS
Configuration Bits BRG/EUSART Mode Baud Rate Formula
SYNC BRG16 BRGH
000 8-bit/Asynchronous FOSC/[64 (n + 1)]
001 8-bit/Asynchronous FOSC/[16 (n + 1)]
010 16-bit/Asynchronous
011 16-bit/Asynchronous
FOSC/[4 (n + 1)]10x 8-bit/Synchronous
11x 16-bit/Synchronous
Legend: x = Don’t care, n = value of SPBRGHx:SPBRGx register pair
PIC18F87J11 FAMILY
DS39778C-page 274 Preliminary © 2008 Microchip Technology Inc.
EXAMPLE 20-1: CALCULATING BAUD RATE ERROR
TABLE 20-2: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values
on Page:
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 57
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 57
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 59
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 59
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 59
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the BRG.
For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, and 8-bit BRG:
Desired Baud Rate = FOSC/(64 ([SPBRGHx:SPBRGx] + 1))
Solving for SPBRGHx:SPBRGx:
X = ((FOSC/Desired Baud Rate)/64) – 1
= ((16000000/9600)/64) – 1
= [25.042] = 25
Calculated Baud Rate = 16000000/(64 (25 + 1))
= 9615
Error = (Calculated Baud Rate – Desired Baud Rate)/Desired Baud Rate
= (9615 – 9600)/9600 = 0.16%
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 275
PIC18F87J11 FAMILY
TABLE 20-3: BAUD RATES FOR ASYNCHRONOUS MODES
BAUD
RATE
(K)
SYNC = 0, BRGH = 0, BRG16 = 0
FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3——————————
1.2 1.221 1.73 255 1.202 0.16 129 1.201 -0.16 103
2.4 2.441 1.73 255 2.404 0.16 129 2.404 0.16 64 2.403 -0.16 51
9.6 9.615 0.16 64 9.766 1.73 31 9.766 1.73 15 9.615 -0.16 12
19.2 19.531 1.73 31 19.531 1.73 15 19.531 1.73 7
57.6 56.818 -1.36 10 62.500 8.51 4 52.083 -9.58 2
115.2 125.000 8.51 4 104.167 -9.58 2 78.125 -32.18 1
BAUD
RATE
(K)
SYNC = 0, BRGH = 0, BRG16 = 0
FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 0.16 207 0.300 -0.16 103 0.300 -0.16 51
1.2 1.202 0.16 51 1.201 -0.16 25 1.201 -0.16 12
2.4 2.404 0.16 25 2.403 -0.16 12
9.6 8.929 -6.99 6
19.2 20.833 8.51 2
57.6 62.500 8.51 0
115.2 62.500 -45.75 0
BAUD
RATE
(K)
SYNC = 0, BRGH = 1, BRG16 = 0
FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3——————————
1.2——————————
2.4 2.441 1.73 255 2.403 -0.16 207
9.6 9.766 1.73 255 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51
19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25
57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8
115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4
BAUD
RATE
(K)
SYNC = 0, BRGH = 1, BRG16 = 0
FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 -0.16 207
1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51
2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25
9.6 9.615 0.16 25 9.615 -0.16 12
19.2 19.231 0.16 12
57.6 62.500 8.51 3
115.2 125.000 8.51 1
PIC18F87J11 FAMILY
DS39778C-page 276 Preliminary © 2008 Microchip Technology Inc.
BAUD
RATE
(K)
SYNC = 0, BRGH = 0, BRG16 = 1
FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 0.00 8332 0.300 0.02 4165 0.300 0.02 2082 0.300 -0.04 1665
1.2 1.200 0.02 2082 1.200 -0.03 1041 1.200 -0.03 520 1.201 -0.16 415
2.4 2.402 0.06 1040 2.399 -0.03 520 2.404 0.16 259 2.403 -0.16 207
9.6 9.615 0.16 259 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51
19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25
57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8
115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4
BAUD
RATE
(K)
SYNC = 0, BRGH = 0, BRG16 = 1
FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 0.04 832 0.300 -0.16 415 0.300 -0.16 207
1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51
2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25
9.6 9.615 0.16 25 9.615 -0.16 12
19.2 19.231 0.16 12
57.6 62.500 8.51 3
115.2 125.000 8.51 1
BAUD
RATE
(K)
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 0.00 33332 0.300 0.00 16665 0.300 0.00 8332 0.300 -0.01 6665
1.2 1.200 0.00 8332 1.200 0.02 4165 1.200 0.02 2082 1.200 -0.04 1665
2.4 2.400 0.02 4165 2.400 0.02 2082 2.402 0.06 1040 2.400 -0.04 832
9.6 9.606 0.06 1040 9.596 -0.03 520 9.615 0.16 259 9.615 -0.16 207
19.2 19.193 -0.03 520 19.231 0.16 259 19.231 0.16 129 19.230 -0.16 103
57.6 57.803 0.35 172 57.471 -0.22 86 58.140 0.94 42 57.142 0.79 34
115.2 114.943 -0.22 86 116.279 0.94 42 113.636 -1.36 21 117.647 -2.12 16
BAUD
RATE
(K)
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 0.01 3332 0.300 -0.04 1665 0.300 -0.04 832
1.2 1.200 0.04 832 1.201 -0.16 415 1.201 -0.16 207
2.4 2.404 0.16 415 2.403 -0.16 207 2.403 -0.16 103
9.6 9.615 0.16 103 9.615 -0.16 51 9.615 -0.16 25
19.2 19.231 0.16 51 19.230 -0.16 25 19.230 -0.16 12
57.6 58.824 2.12 16 55.555 3.55 8
115.2 111.111 -3.55 8
TABLE 20-3: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 277
PIC18F87J11 FAMILY
20.1.3 AUTO-BAUD RATE DETECT
The Enhanced USART module supports the automatic
detection and calibration of baud rate. This feature is
active only in Asynchronous mode and while the WUE
bit is clear.
The automatic baud rate measurement sequence
(Figure 20-1) begins whenever a Start bit is received
and the ABDEN bit is set. The calculation is
self-averaging.
In the Auto-Baud Rate Detect (ABD) mode, the clock to
the BRG is reversed. Rather than the BRG clocking the
incoming RXx signal, the RXx signal is timing the BRG.
In ABD mode, the internal Baud Rate Generator is
used as a counter to time the bit period of the incoming
serial byte stream.
Once the ABDEN bit is set, the state machine will clear
the BRG and look for a Start bit. The Auto-Baud Rate
Detect must receive a byte with the value 55h (ASCII
“U”, which is also the LIN bus Sync character) in order to
calculate the proper bit rate. The measurement is taken
over both a low and a high bit time in order to minimize
any effects caused by asymmetry of the incoming signal.
After a Start bit, the SPBRGx begins counting up, using
the preselected clock source on the first rising edge of
RXx. After eight bits on the RXx pin or the fifth rising
edge, an accumulated value totalling the proper BRG
period is left in the SPBRGHx:SPBRGx register pair.
Once the 5th edge is seen (this should correspond to the
Stop bit), the ABDEN bit is automatically cleared.
If a rollover of the BRG occurs (an overflow from FFFFh
to 0000h), the event is trapped by the ABDOVF status
bit (BAUDCONx<7>). It is set in hardware by BRG roll-
overs and can be set or cleared by the user in software.
ABD mode remains active after rollover events and the
ABDEN bit remains set (Figure 20-2).
While calibrating the baud rate period, the BRG regis-
ters are clocked at 1/8th the preconfigured clock rate.
Note that the BRG clock will be configured by the
BRG16 and BRGH bits. This allows the user to verify
that no carry occurred for 8-bit modes by checking for
00h in the SPBRGHx register. Refer to Table 20-4 for
counter clock rates to the BRG.
While the ABD sequence takes place, the EUSART
state machine is held in Idle. The RCxIF interrupt is set
once the fifth rising edge on RXx is detected. The value
in the RCREGx needs to be read to clear the RCxIF
interrupt. The contents of RCREGx should be
discarded.
TABLE 20-4: BRG COUNTER
CLOCK RATES
20.1.3.1 ABD and EUSART Transmission
Since the BRG clock is reversed during ABD acquisi-
tion, the EUSART transmitter cannot be used during
ABD. This means that whenever the ABDEN bit is set,
TXREGx cannot be written to. Users should also
ensure that ABDEN does not become set during a
transmit sequence. Failing to do this may result in
unpredictable EUSART operation.
Note 1: If the WUE bit is set with the ABDEN bit,
Auto-Baud Rate Detection will occur on
the byte following the Break character.
2: It is up to the user to determine that the
incoming character baud rate is within the
range of the selected BRG clock source.
Some combinations of oscillator frequency
and EUSART baud rates are not possible
due to bit error rates. Overall system tim-
ing and communication baud rates must
be taken into consideration when using the
Auto-Baud Rate Detection feature.
3: Ensure that BRG16 (BAUDCON<3>) is
set, to enable the auto-baud feature.
BRG16 BRGH BRG Counter Clock
00 FOSC/512
01 FOSC/128
10 FOSC/128
11 FOSC/32
Note: During the ABD sequence, SPBRGx and
SPBRGHx are both used as a 16-bit counter,
independent of BRG16 setting.
PIC18F87J11 FAMILY
DS39778C-page 278 Preliminary © 2008 Microchip Technology Inc.
FIGURE 20-1: AUTOMATIC BAUD RATE CALCULATION
FIGURE 20-2: BRG OVERFLOW SEQUENCE
BRG Value
RXx pin
ABDEN bit
RCxIF bit
Bit 0 Bit 1
(Interrupt)
Read
RCREGx
BRG Clock
Start
Auto-Cleared
Set by User
XXXXh 0000h
Edge #1
Bit 2 Bit 3
Edge #2
Bit 4 Bit 5
Edge #3
Bit 6 Bit 7
Edge #4
001Ch
Note: The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0.
SPBRGx XXXXh 1Ch
SPBRGHx XXXXh 00h
Edge #5
Stop Bit
Start Bit 0
XXXXh 0000h 0000h
FFFFh
BRG Clock
ABDEN bit
RXx pin
ABDOVF bit
BRG Value
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 279
PIC18F87J11 FAMILY
20.2 EUSART Asynchronous Mode
The Asynchronous mode of operation is selected by
clearing the SYNC bit (TXSTAx<4>). In this mode, the
EUSART uses standard Non-Return-to-Zero (NRZ)
format (one Start bit, eight or nine data bits and one Stop
bit). The most common data format is 8 bits. An on-chip,
dedicated 8-bit/16-bit Baud Rate Generator can be used
to derive standard baud rate frequencies from the
oscillator.
The EUSART transmits and receives the LSb first. The
EUSART’s transmitter and receiver are functionally
independent but use the same data format and baud
rate. The Baud Rate Generator produces a clock, either
x16 or x64 of the bit shift rate, depending on the BRGH
and BRG16 bits (TXSTAx<2> and BAUDCONx<3>).
Parity is not supported by the hardware but can be
implemented in software and stored as the 9th data bit.
When operating in Asynchronous mode, the EUSART
module consists of the following important elements:
Baud Rate Generator
Sampling Circuit
Asynchronous Transmitter
Asynchronous Receiver
Auto-Wake-up on Sync Break Character
12-Bit Break Character Transmit
Auto-Baud Rate Detection
20.2.1 EUSART ASYNCHRONOUS
TRANSMITTER
The EUSART transmitter block diagram is shown in
Figure 20-3. The heart of the transmitter is the Transmit
(Serial) Shift Register (TSR). The Shift register obtains
its data from the Read/Write Transmit Buffer register,
TXREGx. The TXREGx register is loaded with data in
software. The TSR register is not loaded until the Stop
bit has been transmitted from the previous load. As
soon as the Stop bit is transmitted, the TSR is loaded
with new data from the TXREGx register (if available).
Once the TXREGx register transfers the data to the TSR
register (occurs in one T
CY), the TXREGx register is
empty and the TXxIF flag bit is set. This interrupt can be
enabled or disabled by setting or clearing the interrupt
enable bit, TXxIE. TXxIF will be set regardless of the
state of TXxIE; it cannot be cleared in software. TXxIF is
also not cleared immediately upon loading TXREGx, but
becomes valid in the second instruction cycle following
the load instruction. Polling TXxIF immediately following
a load of TXREGx will return invalid results.
While TXxIF indicates the status of the TXREGx regis-
ter; another bit, TRMT (TXSTAx<1>), shows the status
of the TSR register. TRMT is a read-only bit which is set
when the TSR register is empty. No interrupt logic is
tied to this bit so the user has to poll this bit in order to
determine if the TSR register is empty.
To set up an Asynchronous Transmission:
1. Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
2. Enable the asynchronous serial port by clearing
bit SYNC and setting bit, SPEN.
3. If interrupts are desired, set enable bit, TXxIE.
4. If 9-bit transmission is desired, set transmit bit
TX9. Can be used as address/data bit.
5. Enable the transmission by setting bit, TXEN,
which will also set bit, TXxIF.
6. If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
7. Load data to the TXREGx register (starts
transmission).
8. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
FIGURE 20-3: EUSART TRANSMIT BLOCK DIAGRAM
Note 1: The TSR register is not mapped in data
memory, so it is not available to the user.
2: Flag bit, TXxIF, is set when enable bit,
TXEN, is set.
TXxIF
TXxIE
Interrupt
TXEN Baud Rate CLK
SPBRGx
Baud Rate Generator TX9D
MSb LSb
Data Bus
TXREGx Register
TSR Register
(8) 0
TX9
TRMT SPEN
TXx pin
Pin Buffer
and Control
8
• •
SPBRGHx
BRG16
PIC18F87J11 FAMILY
DS39778C-page 280 Preliminary © 2008 Microchip Technology Inc.
FIGURE 20-4: ASYNCHRONOUS TRANSMISSION
FIGURE 20-5: ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)
TABLE 20-5: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 57
TXREGx EUSARTx Transmit Register 57
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 57
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 59
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 59
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 59
Legend: = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.
Word 1
Word 1
Transmit Shift Reg
Start bit bit 0 bit 1 bit 7/8
Write to TXREGx
BRG Output
(Shift Clock)
TXx (pin)
TXxIF bit
(Transmit Buffer
Reg. Empty Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
1 TCY
Stop bit
Word 1
Transmit Shift Reg.
Write to TXREGx
BRG Output
(Shift Clock)
TXx (pin)
TXxIF bit
(Interrupt Reg. Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Word 1 Word 2
Word 1 Word 2
Stop bit Start bit
Transmit Shift Reg.
Word 1 Word 2
bit 0 bit 1 bit 7/8 bit 0
Note: This timing diagram shows two consecutive transmissions.
1 TCY
1 TCY
Start bit
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 281
PIC18F87J11 FAMILY
20.2.2 EUSART ASYNCHRONOUS
RECEIVER
The receiver block diagram is shown in Figure 20-6.
The data is received on the RXx pin and drives the data
recovery block. The data recovery block is actually a
high-speed shifter operating at x16 times the baud rate,
whereas the main receive serial shifter operates at the
bit rate or at FOSC. This mode would typically be used
in RS-232 systems.
To set up an Asynchronous Reception:
1. Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
2. Enable the asynchronous serial port by clearing
bit, SYNC, and setting bit, SPEN.
3. If interrupts are desired, set enable bit, RCxIE.
4. If 9-bit reception is desired, set bit, RX9.
5. Enable the reception by setting bit, CREN.
6. Flag bit, RCxIF, will be set when reception is
complete and an interrupt will be generated if
enable bit, RCxIE, was set.
7. Read the RCSTAx register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
8. Read the 8-bit received data by reading the
RCREGx register.
9. If any error occurred, clear the error by clearing
enable bit, CREN.
10. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
20.2.3 SETTING UP 9-BIT MODE WITH
ADDRESS DETECT
This mode would typically be used in RS-485 systems.
To set up an Asynchronous Reception with Address
Detect Enable:
1. Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
2. Enable the asynchronous serial port by clearing
the SYNC bit and setting the SPEN bit.
3. If interrupts are required, set the RCEN bit and
select the desired priority level with the RCxIP bit.
4. Set the RX9 bit to enable 9-bit reception.
5. Set the ADDEN bit to enable address detect.
6. Enable reception by setting the CREN bit.
7. The RCxIF bit will be set when reception is
complete. The interrupt will be Acknowledged if
the RCxIE and GIE bits are set.
8. Read the RCSTAx register to determine if any
error occurred during reception, as well as read
bit 9 of data (if applicable).
9. Read RCREGx to determine if the device is
being addressed.
10. If any error occurred, clear the CREN bit.
11. If the device has been addressed, clear the
ADDEN bit to allow all received data into the
receive buffer and interrupt the CPU.
FIGURE 20-6: EUSART RECEIVE BLOCK DIAGRAM
x64 Baud Rate CLK
Baud Rate Generator
RXx
Pin Buffer
and Control
SPEN
Data
Recovery
CREN OERR FERR
RSR Register
MSb LSb
RX9D RCREGx Register
FIFO
Interrupt RCxIF
RCxIE
Data Bus
8
÷ 64
÷ 16
or
Stop Start
(8) 7 1 0
RX9
• • •
SPBRGxSPBRGHx
BRG16
or
÷ 4
PIC18F87J11 FAMILY
DS39778C-page 282 Preliminary © 2008 Microchip Technology Inc.
FIGURE 20-7: ASYNCHRONOUS RECEPTION
TABLE 20-6: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
20.2.4 AUTO-WAKE-UP ON SYNC BREAK
CHARACTER
During Sleep mode, all clocks to the EUSART are
suspended. Because of this, the Baud Rate Generator
is inactive and a proper byte reception cannot be per-
formed. The auto-wake-up feature allows the controller
to wake-up due to activity on the RXx/DTx line while the
EUSART is operating in Asynchronous mode.
The auto-wake-up feature is enabled by setting the
WUE bit (BAUDCONx<1>). Once set, the typical
receive sequence on RXx/DTx is disabled and the
EUSART remains in an Idle state, monitoring for a
wake-up event independent of the CPU mode. A
wake-up event consists of a high-to-low transition on
the RXx/DTx line. (This coincides with the start of a
Sync Break or a Wake-up Signal character for the LIN
protocol.)
Following a wake-up event, the module generates an
RCxIF interrupt. The interrupt is generated synchro-
nously to the Q clocks in normal operating modes
(Figure 20-8) and asynchronously if the device is in
Sleep mode (Figure 20-9). The interrupt condition is
cleared by reading the RCREGx register.
The WUE bit is automatically cleared once a low-to-high
transition is observed on the RXx line following the
wake-up event. At this point, the EUSART module is in
Idle mode and returns to normal operation. This signals
to the user that the Sync Break event is over.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 57
RCREGx EUSARTx Receive Register 57
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 57
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 59
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 59
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 59
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.
Start
bit bit 7/8
bit 1bit 0 bit 7/8 bit 0
Stop
bit
Start
bit
Start
bit
bit 7/8 Stop
bit
RXx (pin)
Rcv Buffer Reg
Rcv Shift Reg
Read Rcv
Buffer Reg
RCREGx
RCxIF
(Interrupt Flag)
OERR bit
CREN
Word 1
RCREGx
Word 2
RCREGx
Stop
bit
Note: This timing diagram shows three words appearing on the RXx input. The RCREGx (Receive Buffer) is read after the third word
causing the OERR (Overrun) bit to be set.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 283
PIC18F87J11 FAMILY
20.2.4.1 Special Considerations Using
Auto-Wake-up
Since auto-wake-up functions by sensing rising edge
transitions on RXx/DTx, information with any state
changes before the Stop bit may signal a false
End-of-Character (EOC) and cause data or framing
errors. To work properly, therefore, the initial character
in the transmission must be all ‘0’s. This can be 00h
(8 bytes) for standard RS-232 devices or 000h (12 bits)
for LIN bus.
Oscillator start-up time must also be considered,
especially in applications using oscillators with longer
start-up intervals (i.e., HS or HSPLL mode). The Sync
Break (or Wake-up Signal) character must be of
sufficient length and be followed by a sufficient interval
to allow enough time for the selected oscillator to start
and provide proper initialization of the EUSART.
20.2.4.2 Special Considerations Using
the WUE Bit
The timing of WUE and RCxIF events may cause some
confusion when it comes to determining the validity of
received data. As noted, setting the WUE bit places the
EUSART in an Idle mode. The wake-up event causes a
receive interrupt by setting the RCxIF bit. The WUE bit
is cleared after this when a rising edge is seen on
RXx/DTx. The interrupt condition is then cleared by
reading the RCREGx register. Ordinarily, the data in
RCREGx will be dummy data and should be discarded.
The fact that the WUE bit has been cleared (or is still
set) and the RCxIF flag is set should not be used as an
indicator of the integrity of the data in RCREGx. Users
should consider implementing a parallel method in
firmware to verify received data integrity.
To assure that no actual data is lost, check the RCIDL
bit to verify that a receive operation is not in process. If
a receive operation is not occurring, the WUE bit may
then be set just prior to entering the Sleep mode.
FIGURE 20-8: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING NORMAL OPERATION
FIGURE 20-9: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
WUE bit(1)
RXx/DTx Line
RCxIF
Note 1: The EUSART remains in Idle while the WUE bit is set.
Bit set by user
Cleared due to user read of RCREGx
Auto-Cleared
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
WUE bit(2)
RXx/DTx Line
RCxIF
Cleared due to user read of RCREGx
SLEEP Command Executed
Note 1: If the wake-up event requires long oscillator warm-up time, the auto-clear of the WUE bit can occur before the oscillator is ready. This
sequence should not depend on the presence of Q clocks.
2: The EUSART remains in Idle while the WUE bit is set.
Sleep Ends
Note 1
Auto-Cleared
Bit set by user
PIC18F87J11 FAMILY
DS39778C-page 284 Preliminary © 2008 Microchip Technology Inc.
20.2.5 BREAK CHARACTER SEQUENCE
The EUSART module has the capability of sending the
special Break character sequences that are required by
the LIN bus standard. The Break character transmit
consists of a Start bit, followed by twelve ‘0’ bits and a
Stop bit. The Frame Break character is sent whenever
the SENDB and TXEN bits (TXSTAx<3> and
TXSTAx<5>) are set while the Transmit Shift Register
is loaded with data. Note that the value of data written
to TXREGx will be ignored and all0s will be
transmitted.
The SENDB bit is automatically reset by hardware after
the corresponding Stop bit is sent. This allows the user
to preload the transmit FIFO with the next transmit byte
following the Break character (typically, the Sync
character in the LIN specification).
Note that the data value written to the TXREGx for the
Break character is ignored. The write simply serves the
purpose of initiating the proper sequence.
The TRMT bit indicates when the transmit operation is
active or Idle, just as it does during normal transmis-
sion. See Figure 20-10 for the timing of the Break
character sequence.
20.2.5.1 Break and Sync Transmit Sequence
The following sequence will send a message frame
header made up of a Break, followed by an Auto-Baud
Sync byte. This sequence is typical of a LIN bus
master.
1. Configure the EUSART for the desired mode.
2. Set the TXEN and SENDB bits to set up the
Break character.
3. Load the TXREGx with a dummy character to
initiate transmission (the value is ignored).
4. Write ‘55h’ to TXREGx to load the Sync
character into the transmit FIFO buffer.
5. After the Break has been sent, the SENDB bit is
reset by hardware. The Sync character now
transmits in the preconfigured mode.
When the TXREGx becomes empty, as indicated by
the TXxIF, the next data byte can be written to
TXREGx.
20.2.6 RECEIVING A BREAK CHARACTER
The Enhanced USART module can receive a Break
character in two ways.
The first method forces configuration of the baud rate
at a frequency of 9/13 the typical speed. This allows for
the Stop bit transition to be at the correct sampling
location (13 bits for Break versus Start bit and 8 data
bits for typical data).
The second method uses the auto-wake-up feature
described in Section 20.2.4 “Auto-Wake-up on Sync
Break Character”. By enabling this feature, the
EUSART will sample the next two transitions on
RXx/DTx, cause an RCxIF interrupt and receive the
next data byte followed by another interrupt.
Note that following a Break character, the user will
typically want to enable the Auto-Baud Rate Detect
feature. For both methods, the user can set the ABDEN
bit once the TXxIF interrupt is observed.
FIGURE 20-10: SEND BREAK CHARACTER SEQUENCE
Write to TXREGx
BRG Output
(Shift Clock)
Start Bit Bit 0 Bit 1 Bit 11 Stop Bit
Break
TXxIF bit
(Transmit Buffer
Reg. Empty Flag)
TXx (pin)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
SENDB bit
(Transmit Shift
Reg. Empty Flag)
SENDB sampled here Auto-Cleared
Dummy Write
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 285
PIC18F87J11 FAMILY
20.3 EUSART Synchronous
Master Mode
The Synchronous Master mode is entered by setting
the CSRC bit (TXSTAx<7>). In this mode, the data is
transmitted in a half-duplex manner (i.e., transmission
and reception do not occur at the same time). When
transmitting data, the reception is inhibited and vice
versa. Synchronous mode is entered by setting bit,
SYNC (TXSTAx<4>). In addition, enable bit, SPEN
(RCSTAx<7>), is set in order to configure the TXx and
RXx pins to CKx (clock) and DTx (data) lines,
respectively.
The Master mode indicates that the processor trans-
mits the master clock on the CKx line. Clock polarity is
selected with the TXCKP bit (BAUDCONx<4>). Setting
TXCKP sets the Idle state on CKx as high, while clear-
ing the bit sets the Idle state as low. This option is
provided to support Microwire devices with this module.
20.3.1 EUSART SYNCHRONOUS MASTER
TRANSMISSION
The EUSART transmitter block diagram is shown in
Figure 20-3. The heart of the transmitter is the Transmit
(Serial) Shift Register (TSR). The Shift register obtains
its data from the Read/Write Transmit Buffer register,
TXREGx. The TXREGx register is loaded with data in
software. The TSR register is not loaded until the last
bit has been transmitted from the previous load. As
soon as the last bit is transmitted, the TSR is loaded
with new data from the TXREGx (if available).
Once the TXREGx register transfers the data to the
TSR register (occurs in one TCY), the TXREGx is empty
and the TXxIF flag bit is set. The interrupt can be
enabled or disabled by setting or clearing the interrupt
enable bit, TXxIE. TXxIF is set regardless of the state
of enable bit, TXxIE; it cannot be cleared in software. It
will reset only when new data is loaded into the
TXREGx register.
While flag bit, TXxIF, indicates the status of the TXREGx
register, another bit, TRMT (TXSTAx<1>), shows the
status of the TSR register. TRMT is a read-only bit which
is set when the TSR is empty. No interrupt logic is tied to
this bit, so the user must poll this bit in order to determine
if the TSR register is empty. The TSR is not mapped in
data memory so it is not available to the user.
To set up a Synchronous Master Transmission:
1. Initialize the SPBRGHx:SPBRGx registers for the
appropriate baud rate. Set or clear the BRG16
bit, as required, to achieve the desired baud rate.
2. Enable the synchronous master serial port by
setting bits, SYNC, SPEN and CSRC.
3. If interrupts are desired, set enable bit, TXxIE.
4. If 9-bit transmission is desired, set bit, TX9.
5. Enable the transmission by setting bit, TXEN.
6. If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
7. Start transmission by loading data to the
TXREGx register.
8. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
FIGURE 20-11: SYNCHRONOUS TRANSMISSION
bit 0 bit 1 bit 7
Word 1
Q1 Q2 Q3Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q3 Q4 Q1 Q2 Q3Q4 Q1Q2 Q3 Q4 Q1 Q2Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
bit 2 bit 0 bit 1 bit 7RC7/RX1/DT1
RC6/TX1/CK1 pin
Write to
TXREG1 Reg
TX1IF bit
(Interrupt Flag)
TXEN bit 1 1
Word 2
TRMT bit
Write Word 1 Write Word 2
Note: Sync Master mode, SPBRGx = 0, continuous transmission of two 8-bit words. This example is equally applicable to EUSART2
(RG1/TX2/CK2 and RG2/RX2/DT2).
RC6/TX1/CK1 pin
(TXCKP = 0)
(TXCKP = 1)
PIC18F87J11 FAMILY
DS39778C-page 286 Preliminary © 2008 Microchip Technology Inc.
FIGURE 20-12: SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
TABLE 20-7: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
RC7/RX1/DT1 pin
RC6/TX1/CK1 pin
Write to
TXREG1 reg
TX1IF bit
TRMT bit
bit 0 bit 1 bit 2 bit 6 bit 7
TXEN bit
Note: This example is equally applicable to EUSART2 (RG1/TX2/CK2 and RG2/RX2/DT2).
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 57
TXREGx EUSARTx Transmit Register 57
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 57
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 59
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 59
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 59
Legend: = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 287
PIC18F87J11 FAMILY
20.3.2 EUSART SYNCHRONOUS
MASTER RECEPTION
Once Synchronous mode is selected, reception is
enabled by setting either the Single Receive Enable bit,
SREN (RCSTAx<5>) or the Continuous Receive
Enable bit, CREN (RCSTAx<4>). Data is sampled on
the RXx pin on the falling edge of the clock.
If enable bit, SREN, is set, only a single word is
received. If enable bit, CREN, is set, the reception is
continuous until CREN is cleared. If both bits are set,
then CREN takes precedence.
To set up a Synchronous Master Reception:
1. Initialize the SPBRGHx:SPBRGx registers for the
appropriate baud rate. Set or clear the BRG16
bit, as required, to achieve the desired baud rate.
2. Enable the synchronous master serial port by
setting bits, SYNC, SPEN and CSRC.
3. Ensure bits, CREN and SREN, are clear.
4. If interrupts are desired, set enable bit, RCxIE.
5. If 9-bit reception is desired, set bit, RX9.
6. If a single reception is required, set bit, SREN.
For continuous reception, set bit, CREN.
7. Interrupt flag bit, RCxIF, will be set when recep-
tion is complete and an interrupt will be generated
if the enable bit, RCxIE, was set.
8. Read the RCSTAx register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
9. Read the 8-bit received data by reading the
RCREGx register.
10. If any error occurred, clear the error by clearing
bit CREN.
11. If using interrupts, ensure that the GIE and PEIE bits
in the INTCON register (INTCON<7:6>) are set.
FIGURE 20-13: SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
CREN bit
RC7/RX1/DT1
RC6/TX1/CK1 pin
Write to
bit SREN
SREN bit
RC1IF bit
(Interrupt)
Read
RCREG1
Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q2 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
0
bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7
0
Q1 Q2 Q3 Q4
Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRGH = 0. This example is equally applicable to EUSART2
(RG1/TX2/CK2 and RG2/RX2/DT2).
RC6/TX1/CK1 pin
pin
(TXCKP = 0)
(TXCKP = 1)
PIC18F87J11 FAMILY
DS39778C-page 288 Preliminary © 2008 Microchip Technology Inc.
TABLE 20-8: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
20.4 EUSART Synchronous
Slave Mode
Synchronous Slave mode is entered by clearing bit,
CSRC (TXSTAx<7>). This mode differs from the
Synchronous Master mode in that the shift clock is sup-
plied externally at the CKx pin (instead of being supplied
internally in Master mode). This allows the device to
transfer or receive data while in any low-power mode.
20.4.1 EUSART SYNCHRONOUS
SLAVE TRANSMISSION
The operation of the Synchronous Master and Slave
modes is identical, except in the case of Sleep mode.
If two words are written to the TXREGx and then the
SLEEP instruction is executed, the following will occur:
a) The first word will immediately transfer to the
TSR register and transmit.
b) The second word will remain in the TXREGx
register.
c) Flag bit, TXxIF, will not be set.
d) When the first word has been shifted out of TSR,
the TXREGx register will transfer the second
word to the TSR and flag bit, TXxIF, will now be
set.
e) If enable bit, TXxIE, is set, the interrupt will wake
the chip from Sleep. If the global interrupt is
enabled, the program will branch to the interrupt
vector.
To set up a Synchronous Slave Transmission:
1. Enable the synchronous slave serial port by
setting bits, SYNC and SPEN, and clearing bit,
CSRC.
2. Clear bits, CREN and SREN.
3. If interrupts are desired, set enable bit, TXxIE.
4. If 9-bit transmission is desired, set bit, TX9.
5. Enable the transmission by setting enable bit,
TXEN.
6. If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
7. Start transmission by loading data to the
TXREGx register.
8. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 57
RCREGx EUSARTx Receive Register 57
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 57
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 59
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 59
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 59
Legend: = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 289
PIC18F87J11 FAMILY
TABLE 20-9: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
20.4.2 EUSART SYNCHRONOUS SLAVE
RECEPTION
The operation of the Synchronous Master and Slave
modes is identical, except in the case of Sleep, or any
Idle mode and bit, SREN, which is a “don’t care” in
Slave mode.
If receive is enabled by setting the CREN bit prior to
entering Sleep or any Idle mode, then a word may be
received while in this low-power mode. Once the word
is received, the RSR register will transfer the data to the
RCREGx register. If the RCxIE enable bit is set, the
interrupt generated will wake the chip from the
low-power mode. If the global interrupt is enabled, the
program will branch to the interrupt vector.
To set up a Synchronous Slave Reception:
1. Enable the synchronous master serial port by
setting bits, SYNC and SPEN, and clearing bit,
CSRC.
2. If interrupts are desired, set enable bit, RCxIE.
3. If 9-bit reception is desired, set bit, RX9.
4. To enable reception, set enable bit, CREN.
5. Flag bit, RCxIF, will be set when reception is
complete. An interrupt will be generated if
enable bit, RCxIE, was set.
6. Read the RCSTAx register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
7. Read the 8-bit received data by reading the
RCREGx register.
8. If any error occurred, clear the error by clearing
bit, CREN.
9. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 57
TXREGx EUSARTx Transmit Register 57
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 57
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 59
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 59
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 59
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission.
PIC18F87J11 FAMILY
DS39778C-page 290 Preliminary © 2008 Microchip Technology Inc.
TABLE 20-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CCP5IF CCP4IF CCP3IF 58
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CCP5IE CCP4IE CCP3IE 58
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CCP5IP CCP4IP CCP3IP 58
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 57
RCREGx EUSARTx Receive Register 57
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 57
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 59
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 59
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 59
Legend: = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 291
PIC18F87J11 FAMILY
21.0 10-BIT ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
The Analog-to-Digital (A/D) Converter module has
11 inputs for the 64-pin devices and 15 for the 80-pin
devices. This module allows conversion of an analog
input signal to a corresponding 10-bit digital number.
The module has six registers:
A/D Control Register 0 (ADCON0)
A/D Control Register 1 (ADCON1)
A/D Port Configuration Register 2 (ANCON0)
A/D Port Configuration Register 1 (ANCON1)
A/D Result Registers (ADRESH and ADRESL)
The ADCON0 register, shown in Register 21-1,
controls the operation of the A/D module. The
ADCON1 register, shown in Register 21-2, configures
the A/D clock source, programmed acquisition time and
justification.
REGISTER 21-1: ADCON0: A/D CONTROL REGISTER 0(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
VCFG1 VCFG0 CHS3 CHS2 CHS1 CHS0 GO/DONE ADON
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 VCFG1: Voltage Reference Configuration bit (VREF- source)
1 = VREF- (AN2)
0 = AVSS
bit VCFG0: Voltage Reference Configuration bit (VREF+ source)
1 = VREF+ (AN3)
0 = AVDD
bit 5-2 CHS3:CHS0: Analog Channel Select bits
0000 = Channel 00 (AN0)
0001 = Channel 01 (AN1)
0010 = Channel 02 (AN2)
0011 = Channel 03 (AN3)
0100 = Channel 04 (AN4)
0101 = Unused
0110 = Channel 06 (AN6)
0111 = Channel 07 (AN7)
1000 = Channel 08 (AN8)
1001 = Channel 09 (AN9)
1010 = Channel 10 (AN10)
1011 = Channel 11 (AN11)
1100 = Channel 12 (AN12)(2,3)
1101 = Channel 13 (AN13)(2,3)
1110 = Channel 14 (AN14)(2,3)
1111 = Channel 15 (AN15)(2,3)
bit 1 GO/DONE: A/D Conversion Status bit
When ADON = 1:
1 = A/D conversion in progress
0 = A/D Idle
bit 0 ADON: A/D On bit
1 = A/D Converter module is enabled
0 = A/D Converter module is disabled
Note 1: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
2: These channels are not implemented on 64-pin devices.
3: Performing a conversion on unimplemented channels will return random values.
PIC18F87J11 FAMILY
DS39778C-page 292 Preliminary © 2008 Microchip Technology Inc.
REGISTER 21-2: ADCON1: A/D CONTROL REGISTER 1(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ADFM ADCAL ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 ADFM: A/D Result Format Select bit
1 = Right justified
0 = Left justified
bit 6 ADCAL: A/D Calibration bit
1 = Calibration is performed on next A/D conversion
0 = Normal A/D Converter operation (no conversion is performed)
bit 5-3 ACQT2:ACQT0: A/D Acquisition Time Select bits
111 = 20 T
AD
110 = 16 TAD
101 = 12 TAD
100 = 8 TAD
011 = 6 TAD
010 = 4 TAD
001 = 2 TAD
000 = 0 TAD(1)
bit 2-0 ADCS2:ADCS0: A/D Conversion Clock Select bits
111 = FRC (clock derived from A/D RC oscillator)(2)
110 = FOSC/64
101 = FOSC/16
100 = FOSC/4
011 = FRC (clock derived from A/D RC oscillator)(2)
010 = FOSC/32
001 = FOSC/8
000 = FOSC/2
Note 1: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
2: If the A/D FRC clock source is selected, a delay of one TCY (instruction cycle) is added before the A/D
clock starts. This allows the SLEEP instruction to be executed before starting a conversion.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 293
PIC18F87J11 FAMILY
The ANCON0 and ANCON1 registers are used to
configure the operation of the I/O pin associated with
each analog channel. Setting any one of the PCFG bits
configures the corresponding pin to operate as a digital
only I/O. Clearing a bit configures the pin to operate as
an analog input for either the A/D Converter or the
comparator module; all digital peripherals are disabled,
and digital inputs read as ‘0’. As a rule, I/O pins that are
multiplexed with analog inputs default to analog
operation on device Resets.
ANCON0 and ANCON1 are shared address SFRs, and
use the same addresses as the ADCON1 and
ADCON0 registers. The ANCON registers are
accessed by setting the ADSHR bit (WDTCON<4>).
See Section 5.3.4.1 “Shared Address SFRs” for
more information.
REGISTER 21-3: ANCON0: A/D PORT CONFIGURATION REGISTER 2
R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PCFG7 PCFG6 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 PCFG7:PCFG6: Analog Port Configuration bits (AN7 and AN6)
1 = Pin configured as a digital port
0 = Pin configured as an analog channel; digital input disabled and reads ‘0
bit 5 Unimplemented: Read as0
bit 4-0 PCFG4:PCFG0: Analog Port Configuration bits (AN4 through AN0)
1 = Pin configured as a digital port
0 = Pin configured as an analog channel; digital input disabled and reads ‘0
REGISTER 21-4: ANCON1: A/D PORT CONFIGURATION REGISTER 1
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PCFG15(1) PCFG14(1) PCFG13(1) PCFG12(1) PCFG11 PCFG10 PCFG9 PCFG8
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 PCFG15:PCFG8: Analog Port Configuration bits (AN15 through AN8)
1 = Pin configured as a digital port
0 = Pin configured as an analog channel; digital input disabled and reads0
Note 1: AN15 through AN12 are implemented only on 80-pin devices. For 64-pin devices, the corresponding
PCFGx bits are still implemented for these channels, but have no effect.
PIC18F87J11 FAMILY
DS39778C-page 294 Preliminary © 2008 Microchip Technology Inc.
The analog reference voltage is software selectable to
either the device’s positive and negative supply voltage
(AVDD and AVSS), or the voltage level on the
RA3/AN3/VREF+ and RA2/AN2/VREF- pins.
The A/D Converter has a unique feature of being able
to operate while the device is in Sleep mode. To
operate in Sleep, the A/D conversion clock must be
derived from the A/D’s internal RC oscillator.
The output of the sample and hold is the input into the
converter, which generates the result via successive
approximation.
Each port pin associated with the A/D Converter can be
configured as an analog input or as a digital I/O. The
ADRESH and ADRESL registers contain the result of
the A/D conversion. When the A/D conversion is com-
plete, the result is loaded into the ADRESH:ADRESL
register pair, the GO/DONE bit (ADCON0<1>) is
cleared and A/D Interrupt Flag bit, ADIF, is set.
A device Reset forces all registers to their Reset state.
This forces the A/D module to be turned off and any
conversion in progress is aborted. The value in the
ADRESH:ADRESL register pair is not modified for a
Power-on Reset. These registers will contain unknown
data after a Power-on Reset.
The block diagram of the A/D module is shown in
Figure 21-1.
FIGURE 21-1: A/D BLOCK DIAGRAM
(Input Voltage)
VAIN
VREF+
Reference
Voltage
VDD(2)
VCFG1:VCFG0
CHS3:CHS0
AN7
AN6
AN4
AN3
AN2
AN1
AN0
0111
0110
0100
0011
0010
0001
0000
10-Bit
A/D
VREF-
VSS(2)
Converter
AN15(1)
AN14(1)
AN13(1)
AN12(1)
AN11
AN10
AN9
AN8
1111
1110
1101
1100
1011
1010
1001
1000
Note 1: Channels AN15 through AN12 are not available on 64-pin devices.
2: I/O pins have diode protection to VDD and VSS.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 295
PIC18F87J11 FAMILY
After the A/D module has been configured as desired,
the selected channel must be acquired before the
conversion is started. The analog input channels must
have their corresponding TRIS bits selected as an
input. To determine acquisition time, see Section 21.1
“A/D Acquisition Requirements”. After this acquisi-
tion time has elapsed, the A/D conversion can be
started. An acquisition time can be programmed to
occur between setting the GO/DONE bit and the actual
start of the conversion.
The following steps should be followed to do an A/D
conversion:
1. Configure the A/D module:
Configure the required ADC pins as analog
pins using ANCON0, ANCON1
Set voltage reference using ADCON0
Select A/D input channel (ADCON0)
Select A/D acquisition time (ADCON1)
Select A/D conversion clock (ADCON1)
Turn on A/D module (ADCON0)
2. Configure A/D interrupt (if desired):
Clear ADIF bit
Set ADIE bit
Set GIE bit
3. Wait the required acquisition time (if required).
4. Start conversion:
Set GO/DONE bit (ADCON0<1>)
5. Wait for A/D conversion to complete, by either:
Polling for the GO/DONE bit to be cleared
OR
Waiting for the A/D interrupt
6. Read A/D Result registers (ADRESH:ADRESL);
clear bit, ADIF, if required.
7. For next conversion, go to step 1 or step 2, as
required. The A/D conversion time per bit is
defined as T
AD. A minimum wait of 2 TAD is
required before next acquisition starts.
FIGURE 21-2: ANALOG INPUT MODEL
VAIN CPIN
RSANx
5 pF
VDD
VT = 0.6V
VT = 0.6V ILEAKAGE
RIC 1k
Sampling
Switch
SS RSS
CHOLD = 25 pF
VSS
Sampling Switch
1234
(kΩ)
VDD
±100 nA
Legend: CPIN
VT
ILEAKAGE
RIC
SS
CHOLD
= input capacitance
= threshold voltage
= leakage current at the pin due to
= interconnect resistance
= sampling switch
= sample/hold capacitance (from DAC)
various junctions
= sampling switch resistanceRSS
PIC18F87J11 FAMILY
DS39778C-page 296 Preliminary © 2008 Microchip Technology Inc.
21.1 A/D Acquisition Requirements
For the A/D Converter to meet its specified accuracy,
the charge holding capacitor (CHOLD) must be allowed
to fully charge to the input channel voltage level. The
analog input model is shown in Figure 21-2. The
source impedance (RS) and the internal sampling
switch (RSS) impedance directly affect the time
required to charge the capacitor CHOLD. The sampling
switch (RSS) impedance varies over the device voltage
(VDD). The source impedance affects the offset voltage
at the analog input (due to pin leakage current). The
maximum recommended impedance for analog
sources is 2.5 kΩ. After the analog input channel is
selected (changed), the channel must be sampled for
at least the minimum acquisition time before starting a
conversion.
To calculate the minimum acquisition time,
Equation 21-1 may be used. This equation assumes
that 1/2 LSb error is used (1024 steps for the A/D). The
1/2 LSb error is the maximum error allowed for the A/D
to meet its specified resolution.
Equation 21-3 shows the calculation of the minimum
required acquisition time, T
ACQ. This calculation is
based on the following application system
assumptions:
CHOLD =25 pF
Rs = 2.5 kΩ
Conversion Error 1/2 LSb
VDD =3VRss = 2 kΩ
Temperature = 85°C (system max.)
EQUATION 21-1: ACQUISITION TIME
EQUATION 21-2: A/D MINIMUM CHARGING TIME
EQUATION 21-3: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME
Note: When the conversion is started, the
holding capacitor is disconnected from the
input pin.
TACQ = Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient
=T
AMP + TC + TCOFF
VHOLD = (VREF – (VREF/2048)) • (1 – e(-TC/CHOLD(RIC + RSS + RS)))
or
TC = -(CHOLD)(RIC + RSS + RS) ln(1/2048)
TACQ =TAMP + TC + TCOFF
TAMP =0.2 μs
TCOFF = (Temp – 25°C)(0.02 μs/°C)
(85°C – 25°C)(0.02 μs/°C)
1.2 μs
Temperature coefficient is only required for temperatures > 25°C. Below 25°C, TCOFF = 0 ms.
TC = -(CHOLD)(RIC + RSS + RS) ln(1/2048) μs
-(25 pF) (1 kΩ + 2 kΩ + 2.5 kΩ) ln(0.0004883) μs
1.05 μs
TACQ =0.2 μs + 1.05 μs + 1.2 μs
2.45 μs
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 297
PIC18F87J11 FAMILY
21.2 Selecting and Configuring
Automatic Acquisition Time
The ADCON1 register allows the user to select an
acquisition time that occurs each time the GO/DONE
bit is set.
When the GO/DONE bit is set, sampling is stopped and
a conversion begins. The user is responsible for ensur-
ing the required acquisition time has passed between
selecting the desired input channel and setting the
GO/DONE bit. This occurs when the ACQT2:ACQT0
bits (ADCON1<5:3>) remain in their Reset state (‘000’)
and is compatible with devices that do not offer
programmable acquisition times.
If desired, the ACQT bits can be set to select a pro-
grammable acquisition time for the A/D module. When
the GO/DONE bit is set, the A/D module continues to
sample the input for the selected acquisition time, then
automatically begins a conversion. Since the acquisi-
tion time is programmed, there may be no need to wait
for an acquisition time between selecting a channel and
setting the GO/DONE bit.
In either case, when the conversion is completed, the
GO/DONE bit is cleared, the ADIF flag is set and the
A/D begins sampling the currently selected channel
again. If an acquisition time is programmed, there is
nothing to indicate if the acquisition time has ended or
if the conversion has begun.
21.3 Selecting the A/D Conversion
Clock
The A/D conversion time per bit is defined as TAD. The
A/D conversion requires 11 T
AD per 10-bit conversion.
The source of the A/D conversion clock is software
selectable.
There are seven possible options for TAD:
•2 T
OSC
•4 TOSC
•8 TOSC
•16 TOSC
•32 TOSC
•64 T
OSC
Internal RC Oscillator
For correct A/D conversions, the A/D conversion clock
(T
AD) must be as short as possible but greater than the
minimum TAD (see parameter 130 in Table 27-30 for
more information).
Table 21-1 shows the resultant T
AD times derived from
the device operating frequencies and the A/D clock
source selected.
TABLE 21-1: TAD vs. DEVICE OPERATING
FREQUENCIES
21.4 Configuring Analog Port Pins
The ANCON0, ANCON1, TRISA, TRISF and TRISH
registers control the operation of the A/D port pins. The
port pins needed as analog inputs must have their cor-
responding TRIS bits set (input). If the TRIS bit is
cleared (output), the digital output level (VOH or VOL)
will be converted.
The A/D operation is independent of the state of the
CHS3:CHS0 bits and the TRIS bits.
AD Clock Source (TAD)Maximum
Device
Frequency
Operation ADCS2:ADCS0
2 T
OSC 000 2.86 MHz
4 T
OSC 100 5.71 MHz
8 TOSC 001 11.43 MHz
16 TOSC 101 22.86 MHz
32 TOSC 010 40.00 MHz
64 TOSC 110 40.00 MHz
RC(2) x11 1.00 MHz(1)
Note 1: The RC source has a typical TAD time of
4μs.
2: For device frequencies above 1 MHz, the
device must be in Sleep mode for the
entire conversion or the A/D accuracy may
be out of specification.
Note 1: When reading the PORT register, all pins
configured as analog input channels will
read as cleared (a low level). Pins config-
ured as digital inputs will convert an
analog input. Analog levels on a digitally
configured input will be accurately
converted.
2: Analog levels on any pin defined as a
digital input may cause the digital input
buffer to consume current out of the
device’s specification limits.
PIC18F87J11 FAMILY
DS39778C-page 298 Preliminary © 2008 Microchip Technology Inc.
21.5 A/D Conversions
Figure 21-3 shows the operation of the A/D Converter
after the GO/DONE bit has been set and the
ACQT2:ACQT0 bits are cleared. A conversion is
started after the following instruction to allow entry into
Sleep mode before the conversion begins.
Figure 21-4 shows the operation of the A/D Converter
after the GO/DONE bit has been set, the
ACQT2:ACQT0 bits are set to ‘010’ and selecting a
4TAD acquisition time before the conversion starts.
Clearing the GO/DONE bit during a conversion will
abort the current conversion. The A/D Result register
pair will NOT be updated with the partially completed
A/D conversion sample. This means the
ADRESH:ADRESL registers will continue to contain
the value of the last completed conversion (or the last
value written to the ADRESH:ADRESL registers).
After the A/D conversion is completed or aborted, a
2T
AD wait is required before the next acquisition can be
started. After this wait, acquisition on the selected
channel is automatically started.
21.6 Use of the ECCP2 Trigger
An A/D conversion can be started by the “Special Event
Trigger” of the ECCP2 module. This requires that the
CCP2M3:CCP2M0 bits (CCP2CON<3:0>) be
programmed as ‘1011’ and that the A/D module is
enabled (ADON bit is set). When the trigger occurs, the
GO/DONE bit will be set, starting the A/D acquisition
and conversion, and the Timer1 (or Timer3) counter will
be reset to zero. Timer1 (or Timer3) is reset to auto-
matically repeat the A/D acquisition period with minimal
software overhead (moving ADRESH/ADRESL to the
desired location). The appropriate analog input
channel must be selected and the minimum acquisition
period is either timed by the user, or an appropriate
TACQ time is selected before the Special Event Trigger
sets the GO/DONE bit (starts a conversion).
If the A/D module is not enabled (ADON is cleared), the
Special Event Trigger will be ignored by the A/D module
but will still reset the Timer1 (or Timer3) counter.
FIGURE 21-3: A/D CONVERSION TAD CYCLES (ACQT2:ACQT0 = 000, TACQ = 0)
FIGURE 21-4: A/D CONVERSION TAD CYCLES (ACQT2:ACQT0 = 010, TACQ = 4 TAD)
Note: The GO/DONE bit should NOT be set in
the same instruction that turns on the A/D.
TAD1 TAD2TAD3TAD4 TAD5TAD6 TAD7TAD8TAD11
Set GO/DONE bit
Holding capacitor is disconnected from analog input (typically 100 ns)
TAD9 TAD10
TCY - TAD
Next Q4: ADRESH/ADRESL is loaded, GO/DONE bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
Conversion starts
b0
b9 b6 b5 b4 b3 b2 b1
b8 b7
1234567811
Set GO/DONE bit
(Holding capacitor is disconnected)
910
Next Q4: ADRESH:ADRESL is loaded, GO/DONE bit is cleared,
ADIF bit is set, holding capacitor is reconnected to analog input.
Conversion starts
123 4
(Holding capacitor continues
acquiring input)
TACQT Cycles TAD Cycles
Automatic
Acquisition
Time
b0b9 b6 b5 b4 b3 b2 b1
b8 b7
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 299
PIC18F87J11 FAMILY
21.7 A/D Converter Calibration
The A/D Converter in the PIC18F87J11 family of
devices includes a self-calibration feature which com-
pensates for any offset generated within the module.
The calibration process is automated and is initiated by
setting the ADCAL bit (ADCON1<6>). The next time
the GO/DONE bit is set, the module will perform a
“dummy” conversion (that is, with reading none of the
input channels) and store the resulting value internally
to compensate for the offset. Thus, subsequent offsets
will be compensated. An example of a calibration
routine is shown in Example 21-1.
The calibration process assumes that the device is in a
relatively steady-state operating condition. If A/D
calibration is used, it should be performed after each
device Reset or if there are other major changes in
operating conditions.
21.8 Operation in Power-Managed
Modes
The selection of the automatic acquisition time and A/D
conversion clock is determined in part by the clock
source and frequency while in a power-managed
mode.
If the A/D is expected to operate while the device is in
a power-managed mode, the ACQT2:ACQT0 and
ADCS2:ADCS0 bits in ADCON1 should be updated in
accordance with the power-managed mode clock that
will be used. After the power-managed mode is entered
(either of the power-managed Run modes), an A/D
acquisition or conversion may be started. Once an
acquisition or conversion is started, the device should
continue to be clocked by the same power-managed
mode clock source until the conversion has been com-
pleted. If desired, the device may be placed into the
corresponding power-managed Idle mode during the
conversion.
If the power-managed mode clock frequency is less
than 1 MHz, the A/D RC clock source should be
selected.
Operation in the Sleep mode requires the A/D RC clock
to be selected. If bits, ACQT2:ACQT0, are set to ‘000
and a conversion is started, the conversion will be
delayed one instruction cycle to allow execution of the
SLEEP instruction and entry to Sleep mode. The IDLEN
and SCS bits in the OSCCON register must have
already been cleared prior to starting the conversion.
EXAMPLE 21-1: SAMPLE A/D CALIBRATION ROUTINE
BSF WDTCON,ADSHR ;Enable write/read to the shared SFR
BCF ANCON0,PCFG0 ;Make Channel 0 analog
BCF WDTCON,ADSHR ;Disable write/read to the shared SFR
BSF ADCON0,ADON ;Enable A/D module
BSF ADCON1,ADCAL ;Enable Calibration
BSF ADCON0,GO ;Start a dummy A/D conversion
CALIBRATION ;
BTFSC ADCON0,GO ;Wait for the dummy conversion to finish
BRA CALIBRATION ;
BCF ADCON1,ADCAL ;Calibration done, turn off calibration enable
;Proceed with the actual A/D conversion
PIC18F87J11 FAMILY
DS39778C-page 300 Preliminary © 2008 Microchip Technology Inc.
TABLE 21-2: SUMMARY OF A/D REGISTERS
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH
PEIE/GIEL
TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 58
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 58
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 58
PIR2 OSCFIF CM2IF CM1IF BCL1IF LVDIF TMR3IF CCP2IF 58
PIE2 OSCFIE CM2IE CM1IE BCL1IE LVDIE TMR3IE CCP2IE 58
IPR2 OSCFIP CM2IP CM1IP BCL1IP LVDIP TMR3IP CCP2IP 58
ADRESH A/D Result Register High Byte 57
ADRESL A/D Result Register Low Byte 57
ADCON0(2) VCFG1 VCFG0 CHS3 CHS3 CHS1 CHS0 GO/DONE ADON 57
ANCON0(3) PCFG7 PCFG6 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 57
ADCON1(2) ADFM ADCAL ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 57
ANCON1(3) PCFG15 PCFG14 PCFG13 PCFG12 PCFG11 PCFG10 PCFG9 PCFG8 57
CCP2CON P2M1 P2M0 DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 57
PORTA RA7(4) RA6(4) RA5 RA4 RA3 RA2 RA1 RA0 59
TRISA TRISA7(4) TRISA6(4) TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 58
PORTF RF7RF6RF5RF4RF3RF2RF1 —59
TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 —58
PORTH(1) RH7 RH6 RH5 RH4 RH3 RH2 RH1 RH0 59
TRISH(1) TRISH7 TRISH6 TRISH5 TRISH4 TRISH3 TRISH2 TRISH1 TRISH0 58
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.
Note 1: This register is not implemented on 64-pin devices.
2: Default (legacy) SFR at this address, available when WDTCON<4> = 0.
3: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
4:
These bits are only available in select oscillator modes (FOSC2 Configuration bit =
0
); otherwise, they are
unimplemented.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 301
PIC18F87J11 FAMILY
22.0 COMPARATOR MODULE
The analog comparator module contains two compara-
tors that can be independently configured in a variety of
ways. The inputs can be selected from the analog
inputs and two internal voltage references. The digital
outputs are available at the pin level and can also be
read through the control register. Multiple output and
interrupt event generation are also available. A generic
single comparator from the module is shown in
Figure 22-1.
Key features of the module includes:
Independent comparator control
Programmable input configuration
Output to both pin and register levels
Programmable output polarity
Independent interrupt generation for each
comparator with configurable interrupt-on-change
22.1 Registers
The CMxCON registers (Register 22-1) select the input
and output configuration for each comparator, as well
as the settings for interrupt generation.
The CMSTAT register (Register 22-2) provides the out-
put results of the comparators. The bits in this register
are read-only.
FIGURE 22-1: COMPARATOR SIMPLIFIED BLOCK DIAGRAM
Cx
VIN-
VIN+
COE
CxOUT
0
1(1)
2(1,2)
3
0
1
CCH1:CCH0
CxINB
CxINC
CxIND
VIRV
CxINA
CVREF
CON
Interrupt
Logic
EVPOL<4:3>
COUTx
(CMSTAT<1:0>)
CMxIF
CPOL
Polarity
Logic
CREF
Note 1: Available in 80-pin devices only.
2: Implemented in Comparator 2 only.
-
PIC18F87J11 FAMILY
DS39778C-page 302 Preliminary © 2008 Microchip Technology Inc.
REGISTER 22-1: CMxCON: COMPARATORx CONTROL REGISTER
R/W-0 R/W-0 R/W-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 CON: Comparator Enable bit
1 = Comparator is enabled
0 = Comparator is disabled
bit 6 COE: Comparator Output Enable bit
1 = Comparator output is present on the CxOUT pin
0 = Comparator output is internal only
bit 5 CPOL: Comparator Output Polarity Select bit
1 = Comparator output is inverted
0 = Comparator output is not inverted
bit 4-3 EVPOL1:EVPOL0: Interrupt Polarity Select bits
11 = Interrupt generation on any change of the output(1)
10 = Interrupt generation only on high-to-low transition of the output
01 = Interrupt generation only on low-to-high transition of the output
00 = Interrupt generation is disabled
bit 2 CREF: Comparator Reference Select bit (non-inverting input)
1 = Non-inverting input connects to internal CVREF voltage
0 = Non-inverting input connects to CxINA pin
bit 1-0 CCH1:CCH0: Comparator Channel Select bits
11 = Inverting input of comparator connects to VIRV
10 = Inverting input of comparator connects to CxIND pin(2)
01 = Inverting input of comparator connects to CxINC pin(2)
00 = Inverting input of comparator connects to CxINB pin
Note 1: The CMxIF is automatically set any time this mode is selected and must be cleared by the application after
the initial configuration.
2: Available in 80-pin devices only.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 303
PIC18F87J11 FAMILY
REGISTER 22-2: CMSTAT: COMPARATOR OUTPUT STATUS REGISTER
U-0 U-0 U-0 U-0 U-0 U-0 R-1 R-1
COUT2 COUT1
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-2 Unimplemented: Read as0
bit 1-0 COUT2:COUT1: Comparator x Status bits
If CPOL = 0 (non-inverted polarity):
1 = Comparator’s VIN+ > VIN-
0 = Comparator’s VIN+ < VIN-
If CPOL = 1 (inverted polarity):
1 = Comparator VIN+ < VIN-
0 = Comparator VIN+ > VIN-
PIC18F87J11 FAMILY
DS39778C-page 304 Preliminary © 2008 Microchip Technology Inc.
22.2 Comparator Operation
A single comparator is shown in Figure 22-2, along with
the relationship between the analog input levels and
the digital output. When the analog input at VIN+ is less
than the analog input VIN-, the output of the comparator
is a digital low level. When the analog input at VIN+ is
greater than the analog input VIN-, the output of the
comparator is a digital high level. The shaded areas of
the output of the comparator in Figure 22-2 represent
the uncertainty due to input offsets and response time.
FIGURE 22-2: SINGLE COMPARATOR
22.3 Comparator Response Time
Response time is the minimum time, after selecting a
new reference voltage or input source, before the com-
parator output has a valid level. The response time of
the comparator differs from the settling time of the volt-
age reference. Therefore, both of these times must be
considered when determining the total response to a
comparator input change. Otherwise, the maximum
delay of the comparators should be used (see
Section 27.0 “Electrical Characteristics”).
22.4 Analog Input Connection
Considerations
A simplified circuit for an analog input is shown in
Figure 22-3. Since the analog pins are connected to a
digital output, they have reverse biased diodes to VDD
and VSS. The analog input, therefore, must be between
VSS and VDD. If the input voltage deviates from this
range by more than 0.6V in either direction, one of the
diodes is forward biased and a latch-up condition may
occur. A maximum source impedance of 10 kΩ is
recommended for the analog sources. Any external
component connected to an analog input pin, such as
a capacitor or a Zener diode, should have very little
leakage current.
FIGURE 22-3: COMPARATOR ANALOG INPUT MODEL
Output
VIN-
VIN+
+
VIN+
VIN-
Output
VA
RS < 10k
AIN
CPIN
5 pF
VDD
VT = 0.6V
VT = 0.6V
RIC
ILEAKAGE
±500 nA
VSS
Legend: CPIN = Input Capacitance
VT= Threshold Voltage
ILEAKAGE = Leakage Current at the pin due to various junctions
RIC = Interconnect Resistance
RS= Source Impedance
VA = Analog Voltage
Comparator
Input
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 305
PIC18F87J11 FAMILY
22.5 Comparator Control and
Configuration
Each comparator has up to eight possible combina-
tions of inputs: up to four external analog inputs, and
one of two internal voltage references.
Both comparators allow a selection of the signal from
pin, CxINA, or the voltage from the comparator refer-
ence (CVREF) on the non-inverting channel. This is
compared to either CxINB, CxINC, CxIND or the micro-
controller’s fixed internal reference voltage (VIRV, 1.2V
nominal) on the inverting channel. The comparator
inputs and outputs are tied to fixed I/O pins, defined in
Table 22-1. The available configurations and their
corresponding bit settings are shown in Figure 22-1.
TABLE 22-1: COMPARATOR INPUTS AND
OUTPUTS
22.5.1 COMPARATOR ENABLE AND
INPUT SELECTION
Setting the CON bit of the CMxCON register
(CMxCON<7>) enables the comparator for operation.
Clearing the CON bit disables the comparator resulting
in minimum current consumption.
The CCH1:CCH0 bits in the CMxCON register
(CMxCON<1:0>) direct either one of three analog input
pins, or the Internal Reference Voltage (VIRV), to the
comparator VIN-. Depending on the comparator operat-
ing mode, either an external or internal voltage
reference may be used. The analog signal present at
VIN- is compared to the signal at VIN+ and the digital
output of the comparator is adjusted accordingly.
The external reference is used when CREF = 0
(CMxCON<2>) and VIN+ is connected to the CxINA
pin. When external voltage references are used, the
comparator module can be configured to have the ref-
erence sources externally. The reference signal must
be between VSS and VDD, and can be applied to either
pin of the comparator.
The comparator module also allows the selection of an
internally generated voltage reference (CVREF) from
the comparator voltage reference module. This module
is described in more detail in Section 23.0 “Compara-
tor Voltage Reference Module”. The reference from
the Comparator Voltage Reference module is only
available when CREF = 1. In this mode, the internal
voltage reference is applied to the comparator’s VIN+
pin.
22.5.1.1 Comparator Configurations in 64-Pin
and 80-Pin Devices
In PIC18F87J11 family devices, the C and D input chan-
nels for both comparators are linked to pins in PORTH
and cannot be reassigned to alternate analog inputs.
Because of this, 64-pin devices offer a total of 4 different
configurations for each comparator. In contrast, 80-pin
devices offer a choice of 6 configurations for Comparator
1, and 8 configurations for Comparator 2. The configura-
tions shown in Figure 22-1 are footnoted to indicate
where they are not available.
22.5.2 COMPARATOR ENABLE AND
OUTPUT SELECTION
The comparator outputs are read through the CMSTAT
register. The CMSTAT<0> reads the Comparator 1 out-
put and CMSTAT<1> reads the Comparator 2 output.
These bits are read-only.
The comparator outputs may also be directly output to
the RF1 and RF2 I/O pins by setting the COE bit
(CMxCON<6>). When enabled, multiplexors in the
output path of the pins switch to the output of the com-
parator. The TRISF<1:2> bits still function as the digital
output enable for the RF1 and RF2 pins while in this
mode.
By default, the comparator’s output is at logic high
whenever the voltage on VIN+ is greater than on VIN-.
The polarity of the comparator outputs can be inverted
using the CPOL bit (CMxCON<5>).
The uncertainty of each of the comparators is related to
the input offset voltage and the response time given in
the specifications, as discussed in Section 22.2
“Comparator Operation”.
Comparator Input or Output I/O Pin
1
C1INA (VIN+) RF6
C1INB (VIN-) RF5
C1INC (VIN-)(1) RH6(1)
C1OUT RF2
2
C2INA(VIN+) RF4
C2INB(VIN-) RF3
C2INC(VIN-)(1) RH4(1)
C2IND(VIN-)(1) RH5(1)
C2OUT RF1
Note 1: Available in 80-pin devices only.
Note: The comparator input pin selected by
CCH1:CH0 must be configured as an input
by setting both the corresponding TRISF or
TRISH bit, and the corresponding PCFG bit
in the ANCON1 register.
PIC18F87J11 FAMILY
DS39778C-page 306 Preliminary © 2008 Microchip Technology Inc.
FIGURE 22-4: COMPARATOR I/O CONFIGURATIONS
Cx
VIN-
VIN+Off (Read as ‘0’)
Comparator Off
CON = 0, CREF = x, CCH1:CCH0 = xx COE
CxOUT
pin
Cx
VIN-
VIN+
COE
Comparator CxINB > CxINA Compare
CON = 1, CREF = 0, CCH1:CCH0 = 00
CxINB
CxINA Cx
VIN-
VIN+
COE
Comparator CxINC > CxINA Compare(1)
CON = 1, CREF = 0, CCH1:CCH0 = 01
CxINC
CxINA
Cx
VIN-
VIN+
COE
Comparator CxIND > CxINA Compare(1,2)
CON = 1, CREF = 0, CCH1:CCH0 = 10
CxIND
CxINA Cx
VIN-
VIN+
COE
Comparator VIRV > CxINA Compare
CON = 1, CREF = 0, CCH1:CCH0 = 11
VIRV
CxINA
Cx
VIN-
VIN+
COE
Comparator CxINB > CVREF Compare
CON = 1, CREF = 1, CCH1:CCH0 = 00
CxINB
CVREF Cx
VIN-
VIN+
COE
Comparator CxINC > CVREF Compare(1)
CON = 1, CREF = 1, CCH1:CCH0 = 01
CxINC
CVREF
Cx
VIN-
VIN+
COE
Comparator CxIND > CVREF Compare(1,2)
CON = 1, CREF = 1, CCH1:CCH0 = 10
CxIND
CVREF Cx
VIN-
VIN+
COE
Comparator VIRV > CVREF Compare
CON = 1, CREF = 1, CCH1:CCH0 = 11
VIRV
CVREF
Legend: VIRV = Fixed Interval Reference Voltage (1.2V nominal), CVREF = Comparator Voltage Reference module output.
Configurations are available on both Comparators 1 and 2 in all package sizes unless otherwise noted.
Note 1: Configuration is available in 80-pin devices only.
2: Configuration is available in Comparator 2 only (80-pin devices).
CxOUT
pin
CxOUT
pin
CxOUT
pin
CxOUT
pin CxOUT
pin
CxOUT
pin
CxOUT
pin
CxOUT
pin
-
-
-
--
-
-
-
-
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 307
PIC18F87J11 FAMILY
22.6 Comparator Interrupts
The comparator interrupt flag is set whenever any of
the following occurs:
Low-to-high transition of the comparator output
High-to-low transition of the comparator output
Any change in the comparator output
The comparator interrupt selection is done by the
EVPOL1:EVPOL0 bits in the CMxCON register
(CMxCON<4:3>).
In order to provide maximum flexibility, the output of the
comparator may be inverted using the CPOL bit in the
CMxCON register (CMxCON<5>). This is functionally
identical to reversing the inverting and non-inverting
inputs of the comparator for a particular mode.
An interrupt is generated on the low-to-high or high-to-
low transition of the comparator output. This mode of
interrupt generation is dependent on EVPOL<1:0> in
the CMxCON register. If EVPOL<1:0> = 01 or 10, the
interrupt is generated on a low-to-high or high-to-low
transition of the comparator output. Once the interrupt
is generated, it is required to clear the interrupt flag by
software.
When EVPOL<1:0> = 11, the comparator interrupt flag
is set whenever there is a change in the output value of
either comparator. Software will need to maintain infor-
mation about the status of the output bits, as read from
CMSTAT<1:0>, to determine the actual change that
occurred. The CMxIF bits (PIR2<6:5>) are the Compar-
ator Interrupt Flags. The CMxIF bits must be reset by
clearing them. Since it is also possible to write a 1’ to
this register, a simulated interrupt may be initiated.
Table 22-2 shows the interrupt generation with respect
to comparator input voltages and EVPOL bit settings.
Both the CMxIE bits (PIE2<6:5>) and the PEIE bit
(INTCON<6>) must be set to enable the interrupt. In
addition, the GIE bit (INTCON<7>) must also be set. If
any of these bits are clear, the interrupt is not enabled,
though the CMxIF bits will still be set if an interrupt
condition occurs.
TABLE 22-2: COMPARATOR INTERRUPT GENERATION
CPOL EVPOL<1:0> Comparator
Input Change COUTx Transition Interrupt
Generated
0
00 VIN+ > VIN- Low-to-High No
VIN+ < VIN- High-to-Low No
01 VIN+ > VIN- Low-to-High Yes
VIN+ < VIN- High-to-Low No
10 VIN+ > VIN- Low-to-High No
VIN+ < VIN- High-to-Low Yes
11 VIN+ > VIN- Low-to-High Yes
VIN+ < VIN- High-to-Low Yes
1
00 VIN+ > VIN- High-to-Low No
VIN+ < VIN- Low-to-High No
01 VIN+ > VIN- High-to-Low No
VIN+ < VIN- Low-to-High Yes
10 VIN+ > VIN- High-to-Low Yes
VIN+ < VIN- Low-to-High No
11 VIN+ > VIN- High-to-Low Yes
VIN+ < VIN- Low-to-High Yes
PIC18F87J11 FAMILY
DS39778C-page 308 Preliminary © 2008 Microchip Technology Inc.
22.7 Comparator Operation
During Sleep
When a comparator is active and the device is placed
in Sleep mode, the comparator remains active and the
interrupt is functional if enabled. This interrupt will
wake-up the device from Sleep mode when enabled.
Each operational comparator will consume additional
current. To minimize power consumption while in Sleep
mode, turn off the comparators (CON = 0) before
entering Sleep. If the device wakes up from Sleep, the
contents of the CMxCON register are not affected.
22.8 Effects of a Reset
A device Reset forces the CMxCON registers to their
Reset state. This forces both comparators and the
voltage reference to the OFF state.
TABLE 22-3: REGISTERS ASSOCIATED WITH COMPARATOR MODULE
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 55
PIR2 OSCFIF CM2IF CM1IF BCL1IF LVDIF TMR3IF CCP2IF 58
PIE2 OSCFIE CM2IE CM1IE BCL1IE LVDIE TMR3IE CCP2IE 58
IPR2 OSCFIP CM2IP CM1IP BCL1IP LVDIP TMR3IP CCP2IP 58
CM1CON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 56
CM2CON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 56
CMSTAT ————— COUT2 COUT1 56
CVRCON(2) CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 59
ANCON1(2) PCFG15 PCFG14 PCFG13 PCFG12 PCFG11 PCFG10 PCFG9 PCFG8 57
ANCON0(2) PCFG7 PCFG6 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 57
PORTF RF7 RF6 RF5 RF4 RF3 RF2 RF1 —59
LATF LATF7 LATF6 LATF5 LATF4 LATF3 LATF2 LATF1 —58
TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 —58
PORTH(1) RH7 RH6 RH5 RH4 RH3 RH2 RH1 RH0 59
TRISH(1) TRISH7 TRISH6 TRISH5 TRISH4 TRISH3 TRISH2 TRISH1 TRISH0 58
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.
Note 1: These registers are not implemented on 64-pin devices.
2: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 309
PIC18F87J11 FAMILY
23.0 COMPARATOR VOLTAGE
REFERENCE MODULE
The comparator voltage reference is a 16-tap resistor
ladder network that provides a selectable reference
voltage. Although its primary purpose is to provide a
reference for the analog comparators, it may also be
used independently of them.
A block diagram of the module is shown in Figure 23-1.
The resistor ladder is segmented to provide two ranges
of CVREF values and has a power-down function to
conserve power when the reference is not being used.
The module’s supply reference can be provided from
either device VDD/VSS or an external voltage reference.
FIGURE 23-1: COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
16-to-1 MUX
CVR3:CVR0
8R
R
CVREN
CVRSS = 0
VDD
VREF+CVRSS = 1
8R
CVRSS = 0
VREF-CVRSS = 1
R
R
R
R
R
R
16 Steps
CVRR
CVREF
PIC18F87J11 FAMILY
DS39778C-page 310 Preliminary © 2008 Microchip Technology Inc.
23.1 Configuring the Comparator
Voltage Reference
The comparator voltage reference module is controlled
through the CVRCON register (Register 23-1). The
comparator voltage reference provides two ranges of
output voltage, each with 16 distinct levels. The range
to be used is selected by the CVRR bit (CVRCON<5>).
The primary difference between the ranges is the size
of the steps selected by the CVREF Selection bits
(CVR3:CVR0), with one range offering finer resolution.
The equations used to calculate the output of the
comparator voltage reference are as follows:
If CVRR = 1:
CVREF = ((CVR3:CVR0)/24) x (CVRSRC)
If CVRR = 0:
CVREF =(CVRSRC/4) + ((CVR3:CVR0)/32) x
(CVRSRC)
The comparator reference supply voltage can come
from either VDD and VSS, or the external VREF+ and
VREF- that are multiplexed with RA2 and RA3. The
voltage source is selected by the CVRSS bit
(CVRCON<4>).
The settling time of the comparator voltage reference
must be considered when changing the CVREF
output (see Table 27-3 in Section 27.0 “Electrical
Characteristics).
The CVRCON register is a shared address SFR and
uses the same address as the PR4 register. The
CVRCON register is accessed by setting the ADSHR
bit (WDTCON<4>).
REGISTER 23-1: CVRCON: COMPARATOR VOLTAGE REFERENCE CONTROL REGISTER
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
CVREN CVROE(1) CVRR CVRSS CVR3 CVR2 CVR1 CVR0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 CVREN: Comparator Voltage Reference Enable bit
1 =CVREF circuit powered on
0 =CV
REF circuit powered down
bit 6 CVROE: Comparator VREF Output Enable bit(1)
1 =CVREF voltage level is also output on the RF5/AN10/C1INB/CVREF pin
0 =CV
REF voltage is disconnected from the RF5/AN10/C1INB/CVREF pin
bit 5 CVRR: Comparator VREF Range Selection bit
1 = 0 to 0.667 CVRSRC, with CVRSRC/24 step size (low range)
0 = 0.25 CVRSRC to 0.75 CVRSRC, with CVRSRC/32 step size (high range)
bit 4 CVRSS: Comparator VREF Source Selection bit
1 = Comparator reference source, CVRSRC = (VREF+) – (VREF-)
0 = Comparator reference source, CVRSRC = AVDD – AVSS
bit 3-0 CVR3:CVR0: Comparator VREF Value Selection bits (0 (CVR3:CVR0) 15)
When CVRR = 1:
CVREF = ((CVR3:CVR0)/24) (CVRSRC)
When CVRR = 0:
CVREF = (CVRSRC/4) + ((CVR3:CVR0)/32) (CVRSRC)
Note 1: CVROE overrides the TRISF<5> bit setting.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 311
PIC18F87J11 FAMILY
23.2 Voltage Reference Accuracy/Error
The full range of voltage reference cannot be realized
due to the construction of the module. The transistors
on the top and bottom of the resistor ladder network
(Figure 23-1) keep CVREF from approaching the refer-
ence source rails. The voltage reference is derived
from the reference source; therefore, the CVREF output
changes with fluctuations in that source. The tested
absolute accuracy of the voltage reference can be
found in Section 27.0 “Electrical Characteristics”.
23.3 Connection Considerations
The voltage reference module operates independently
of the comparator module. The output of the reference
generator may be connected to the RF5 pin if the
CVROE bit is set. Enabling the voltage reference out-
put onto RA2 when it is configured as a digital input will
increase current consumption. Connecting RF5 as a
digital output with CVRSS enabled will also increase
current consumption.
The RF5 pin can be used as a simple D/A output with
limited drive capability. Due to the limited current drive
capability, a buffer must be used on the voltage
reference output for external connections to VREF.
Figure 23-2 shows an example buffering technique.
23.4 Operation During Sleep
When the device wakes up from Sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the CVRCON register are not affected. To minimize
current consumption in Sleep mode, the voltage
reference should be disabled.
23.5 Effects of a Reset
A device Reset disables the voltage reference by
clearing CVREN (CVRCON<7>). This Reset also
disconnects the reference from the RA2 pin by clearing
CVROE, and selects the high-voltage range by clearing
CVRR. The CVR value select bits are also cleared.
FIGURE 23-2: COMPARATOR VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE
TABLE 23-1: REGISTERS ASSOCIATED WITH COMPARATOR VOLTAGE REFERENCE
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page:
CVRCON(2) CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 59
CM1CON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 56
CM2CON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 56
TRISA TRISA7(1) TRISA6(1) TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 58
TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 —58
ANCON0(2) PCFG7 PCFG6 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 57
ANCON1(2) PCFG15 PCFG14 PCFG13 PCFG12 PCFG11 PCFG10 PCFG9 PCFG8 57
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used with the comparator voltage reference.
Note 1:
These bits are only available in select oscillator modes (FOSC2 Configuration bit =
0
); otherwise, they are
unimplemented.
2: Configuration SFR, overlaps with default SFR at this address; available only when WDTCON<4> = 1.
CVREF Output
+
CVREF
Module
Voltage
Reference
Output
Impedance
R(1)
RF5
Note 1: R is dependent upon the comparator voltage reference configuration bits, CVRCON<5> and CVRCON<3:0>.
PIC18F87J11
PIC18F87J11 FAMILY
DS39778C-page 312 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 313
PIC18F87J11 FAMILY
24.0 SPECIAL FEATURES OF THE
CPU
PIC18F87J11 Family devices include several features
intended to maximize reliability and minimize cost
through elimination of external components. These are:
Oscillator Selection
Resets:
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR)
Interrupts
Watchdog Timer (WDT)
Fail-Safe Clock Monitor
Two-Speed Start-up
Code Protection
In-Circuit Serial Programming
The oscillator can be configured for the application
depending on frequency, power, accuracy and cost. All
of the options are discussed in detail in Section 2.0
“Oscillator Configurations.
A complete discussion of device Resets and interrupts
is available in previous sections of this data sheet. In
addition to their Power-up and Oscillator Start-up
Timers provided for Resets, the PIC18F87J11 Family
of devices have a configurable Watchdog Timer which
is controlled in software.
The inclusion of an internal RC oscillator also provides
the additional benefits of a Fail-Safe Clock Monitor
(FSCM) and Two-Speed Start-up. FSCM provides for
background monitoring of the peripheral clock and
automatic switchover in the event of its failure.
Two-Speed Start-up enables code to be executed
almost immediately on start-up, while the primary clock
source completes its start-up delays.
All of these features are enabled and configured by
setting the appropriate Configuration register bits.
24.1 Configuration Bits
The Configuration bits can be programmed (read as
0’) or left unprogrammed (read as ‘1’) to select various
device configurations. These bits are mapped starting
at program memory location 300000h. A complete list
is shown in Table 24-2. A detailed explanation of the
various bit functions is provided in Register 24-1
through Register 24-6.
24.1.1 CONSIDERATIONS FOR
CONFIGURING THE PIC18F87J11
FAMILY DEVICES
Unlike previous PIC18 microcontrollers, devices of the
PIC18F87J11 Family do not use persistent memory
registers to store configuration information. The config-
uration bytes are implemented as volatile memory
which means that configuration data must be
programmed each time the device is powered up.
Configuration data is stored in the four words at the top
of the on-chip program memory space, known as the
Flash Configuration Words. It is stored in program
memory in the same order shown in Table 24-2, with
CONFIG1L at the lowest address and CONFIG3H at
the highest. The data is automatically loaded in the
proper Configuration registers during device power-up.
When creating applications for these devices, users
should always specifically allocate the location of the
Flash Configuration Word for configuration data. This is
to make certain that program code is not stored in this
address when the code is compiled.
The volatile memory cells used for the Configuration
bits always reset to ‘1’ on Power-on Resets. For all
other type of Reset events, the previously programmed
values are maintained and used without reloading from
program memory.
The four Most Significant bits of CONFIG1H,
CONFIG2H and CONFIG3H in program memory
should also be ‘1111’. This makes these Configuration
Words appear to be NOP instructions in the remote
event that their locations are ever executed by
accident. Since Configuration bits are not implemented
in the corresponding locations, writing ‘1’s to these
locations has no effect on device operation.
To prevent inadvertent configuration changes during
code execution, all programmable Configuration bits
are write-once. After a bit is initially programmed during
a power cycle, it cannot be written to again. Changing
a device configuration requires that power to the device
be cycled.
PIC18F87J11 FAMILY
DS39778C-page 314 Preliminary © 2008 Microchip Technology Inc.
TABLE 24-1: MAPPING OF THE FLASH CONFIGURATION WORDS TO THE
CONFIGURATION REGISTERS
TABLE 24-2: CONFIGURATION BITS AND DEVICE IDs
Configuration Byte Code Space Address Configuration Register
Address
CONFIG1L XXXF8h 300000h
CONFIG1H XXXF9h 300001h
CONFIG2L XXXFAh 300002h
CONFIG2H XXXFBh 300003h
CONFIG3L XXXFCh 300004h
CONFIG3H XXXFDh 300005h
CONFIG4L(1) XXXFEh 300006h
CONFIG4H(1) XXXFFh 300007h
Note 1: Unimplemented in PIC18F87J11 Family devices.
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Default/
Unprogrammed
Value(1)
300000h CONFIG1L DEBUG XINST STVREN —WDTEN111- ---1
300001h CONFIG1H (2) (2) (2) (2) —CP0 1111 -111
300002h CONFIG2L IESO FCMEN FOSC2 FOSC1 FOSC0 11-- -111
300003h CONFIG2H (2) (2) (2) (2) WDTPS3 WDTPS2 WDTPS1 WDTPS0 1111 1111
300004h CONFIG3L WAIT(3) BW(3) EMB1(3) EMB0(3) EASHFT(3) 1111 1---
300005h CONFIG3H (2) (2) (2) (2) MSSPMSK PMPMX(3) ECCPMX(3) CCP2MX 1111 1111
3FFFFEh DEVID1 DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 xxx0 0000(4)
3FFFFFh DEVID2 DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 0100 00xx(4)
Legend: x = unknown, u = unchanged, - = unimplemented. Shaded cells are unimplemented, read as ‘0’.
Note 1: Values reflect the unprogrammed state as received from the factory and following Power-on Resets. In all other Reset
states, the configuration bytes maintain their previously programmed states.
2: The value of these bits in program memory should always be ‘1’. This ensures that the location is executed as a NOP if it
is accidentally executed.
3: Implemented in 80-pin devices only.
4: See Register 24-7 and Register 24-8 for DEVID values. These registers are read-only and cannot be programmed by
the user.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 315
PIC18F87J11 FAMILY
REGISTER 24-1: CONFIG1L: CONFIGURATION REGISTER 1 LOW (BYTE ADDRESS 300000h)
R/WO-1 R/WO-1 R/WO-1 U-0 U-0 U-0 U-0 R/WO-1
DEBUG XINST STVREN ———WDTEN
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 DEBUG: Background Debugger Enable bit
1 = Background debugger disabled; RB6 and RB7 configured as general purpose I/O pins
0 = Background debugger enabled; RB6 and RB7 are dedicated to In-Circuit Debug
bit 6 XINST: Extended Instruction Set Enable bit
1 = Instruction set extension and Indexed Addressing mode enabled
0 = Instruction set extension and Indexed Addressing mode disabled (Legacy mode)
bit 5 STVREN: Stack Overflow/Underflow Reset Enable bit
1 = Reset on stack overflow/underflow enabled
0 = Reset on stack overflow/underflow disabled
bit 4-1 Unimplemented: Read as ‘0
bit 0 WDTEN: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled (control is placed on SWDTEN bit)
REGISTER 24-2: CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h)
U-1 U-1 U-1 U-1 U-0 R/WO-1 U-1 U-1
—CP0
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-3 Unimplemented: Maintain as ‘01
bit 2 CP0: Code Protection bit
1 = Program memory is not code-protected
0 = Program memory is code-protected
bit 1-0 Unimplemented: Read as ‘0
PIC18F87J11 FAMILY
DS39778C-page 316 Preliminary © 2008 Microchip Technology Inc.
REGISTER 24-3: CONFIG2L: CONFIGURATION REGISTER 2 LOW (BYTE ADDRESS 300002h)
R/WO-1 R/WO-1 U-0 U-0 U-0 R/WO-1 R/WO-1 R/WO-1
IESO FCMEN FOSC2 FOSC1 FOSC0
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IESO: Two-Speed Start-up (Internal/External Oscillator Switchover) Control bit
1 = Two-Speed Start-up enabled
0 = Two-Speed Start-up disabled
bit 6 FCMEN: Fail-Safe Clock Monitor Enable bit
1 = Fail-Safe Clock Monitor enabled
0 = Fail-Safe Clock Monitor disabled
bit 5-3 Unimplemented: Read as ‘0
bit 2-0 FOSC2:FOSC0: Oscillator Selection bits
111 = EC oscillator with PLL enabled; CLKO on RA6 (ECPLL)
110 = EC oscillator; CLKO on RA6 (EC)
101 = HS oscillator with PLL enabled (HSPLL)
100 = HS oscillator (HS)
011 = Internal oscillator with PLL enabled; CLKO on RA6, port function on RA7 (INTPLL1)
010 = Internal oscillator with PLL enabled; port function on RA6 and RA7 (INTPLL2)
001 = Internal oscillator block; CLKO on RA6, port function on RA7 (INTIO1)
000 = Internal oscillator block ; port function on RA6 and RA7 (INTIO2)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 317
PIC18F87J11 FAMILY
REGISTER 24-4: CONFIG2H: CONFIGURATION REGISTER 2 HIGH (BYTE ADDRESS 300003h)
U-1 U-1 U-1 U-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1
WDTPS3 WDTPS2 WDTPS1 WDTPS0
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-4 Unimplemented: Maintain as1
bit 3-0 WDTPS3:WDTPS0: Watchdog Timer Postscale Select bits
1111 = 1:32,768
1110 = 1:16,384
1101 = 1:8,192
1100 = 1:4,096
1011 = 1:2,048
1010 = 1:1,024
1001 = 1:512
1000 = 1:256
0111 = 1:128
0110 = 1:64
0101 = 1:32
0100 = 1:16
0011 = 1:8
0010 = 1:4
0001 = 1:2
0000 = 1:1
PIC18F87J11 FAMILY
DS39778C-page 318 Preliminary © 2008 Microchip Technology Inc.
REGISTER 24-5: CONFIG3L: CONFIGURATION REGISTER 3 LOW (BYTE ADDRESS 300004h)
R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1 U-0 U-0 U-0
WAIT(1) BW(1) EMB1(1) EMB0(1) EASHFT(1) ———
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 WAIT: External Bus Wait Enable bit(1)
1 = Wait states on the external bus are disabled
0 = Wait states on the external bus are enabled and selected by MEMCON<5:4>
bit 6 BW: Data Bus Width Select bit(1)
1 = 16-Bit Data Width modes
0 = 8-Bit Data Width modes
bit 5-4 EMB1:EMB0: External Memory Bus Configuration bits(1)
11 = Microcontroller mode, external bus disabled
10 = Extended Microcontroller mode, 12-bit address width for external bus
01 = Extended Microcontroller mode, 16-bit address width for external bus
00 = Extended Microcontroller mode, 20-bit address width for external bus
bit 3 EASHFT: External Address Bus Shift Enable bit(1)
1 = Address shifting enabled – external address bus is shifted to start at 000000h
0 = Address shifting disabled – external address bus reflects the PC value
bit 2-0 Unimplemented: Read as ‘0
Note 1: Implemented on 80-pin devices only.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 319
PIC18F87J11 FAMILY
REGISTER 24-6: CONFIG3H: CONFIGURATION REGISTER 3 HIGH (BYTE ADDRESS 300005h)
U-1 U-1 U-1 U-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1
MSSPMSK PMPMX(1) ECCPMX(1) CCP2MX
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-4 Unimplemented: Maintain as1
bit 3 MSSPMSK: MSSP Address Masking Mode Select bit
1 = 7-Bit Address Masking mode enabled
0 = 5-Bit Address Masking mode enable
bit 2 PMPMX: PMP Pin Multiplex bit(1)
1 = PMP data and control multiplexed to same pins as external memory bus (PORTD and PORTE)
0 = PMP data and control multiplexed to alternate pin assignments (PORTA, PORTF and PORTH)
bit 1 ECCPMX: ECCPx MUX bit(1)
1 = ECCP1 outputs (P1B/P1C) are multiplexed with RE6 and RE5;
ECCP3 outputs (P3B/P3C) are multiplexed with RE4 and RE3
0 = ECCP1 outputs (P1B/P1C) are multiplexed with RH7 and RH6;
ECCP3 outputs (P3B/P3C) are multiplexed with RH5 and RH4
bit 0 CCP2MX: ECCP2 MUX bit
1 = ECCP2/P2A is multiplexed with RC1
0 = ECCP2/P2A is multiplexed with RE7 in Microcontroller mode (all devices) or with RB3 in Extended
Microcontroller mode (80-pin devices only)
Note 1: Implemented on 80-pin devices only.
PIC18F87J11 FAMILY
DS39778C-page 320 Preliminary © 2008 Microchip Technology Inc.
REGISTER 24-7: DEVID1: DEVICE ID REGISTER 1 FOR PIC18F87J11 FAMILY DEVICES
RRRRRRRR
DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 DEV2:DEV0: Device ID bits
See Register 24-8 for a complete listing.
bit 4-0 REV4:REV0: Revision ID bits
These bits are used to indicate the device revision.
REGISTER 24-8: DEVID2: DEVICE ID REGISTER 2 FOR PIC18F87J11 FAMILY DEVICES
RRRRRRRR
DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 DEV10:DEV3: Device ID bits:
DEV10:DEV3
(DEVID2<7:0>)
DEV2:DEV0
(DEVID1<7:5>) Device
0100 0100 010 PIC18F66J11
0100 0100 011 PIC18F66J16
0100 0100 100 PIC18F67J11
0100 0100 111 PIC18F86J11
0100 0101 000 PIC18F86J16
0100 0101 001 PIC18F87J11
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 321
PIC18F87J11 FAMILY
24.2 Watchdog Timer (WDT)
For PIC18F87J11 Family devices, the WDT is driven by
the INTRC oscillator. When the WDT is enabled, the
clock source is also enabled. The nominal WDT period
is 4 ms and has the same stability as the INTRC
oscillator.
The 4 ms period of the WDT is multiplied by a 16-bit
postscaler. Any output of the WDT postscaler is
selected by a multiplexor, controlled by the WDTPS bits
in Configuration Register 2H. Available periods range
from about 4 ms to 135 seconds (2.25 minutes
depending on voltage, temperature and WDT
postscaler). The WDT and postscaler are cleared
whenever a SLEEP or CLRWDT instruction is executed,
or a clock failure (primary or Timer1 oscillator) has
occurred.
24.2.1 CONTROL REGISTER
The WDTCON register (Register 24-9) is a readable
and writable register. The SWDTEN bit enables or dis-
ables WDT operation. This allows software to override
the WDTEN Configuration bit and enable the WDT only
if it has been disabled by the Configuration bit.
The ADSHR bit selects which SFRs are currently
selected and accessible. See Section 5.3.4.1 “Shared
Address SFRs” for additional details.
The LVDSTAT is a read-only status bit which is continu-
ously updated and provides information about the current
level of VDDCORE. This bit is only valid when the on-chip
voltage regulator is enabled.
FIGURE 24-1: WDT BLOCK DIAGRAM
Note 1: The CLRWDT and SLEEP instructions
clear the WDT and postscaler counts
when executed.
2: When a CLRWDT instruction is executed,
the postscaler count will be cleared.
INTRC Oscillator
WDT
Wake-up from
Reset
WDT
WDT Counter
Programmable Postscaler
1:1 to 1:32,768
Enable WDT
WDTPS3:WDTPS0
SWDTEN
CLRWDT
4
Power-Managed
Reset
All Device Resets
Sleep
INTRC Control
÷128
Modes
PIC18F87J11 FAMILY
DS39778C-page 322 Preliminary © 2008 Microchip Technology Inc.
TABLE 24-3: SUMMARY OF WATCHDOG TIMER REGISTERS
REGISTER 24-9: WDTCON: WATCHDOG TIMER CONTROL REGISTER
R/W-0 R-x U-0 R/W-0 U-0 U-0 U-0 U-0
REGSLP LVDSTAT ADSHR —SWDTEN
(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 REGSLP: Voltage Regulator Low-Power Operation Enable bit
1 = On-chip regulator enters low-power operation when device enters Sleep mode
0 = On-chip regulator is active, even in Sleep mode
bit 6 LVDSTAT: LVD Status bit
1 = VDDCORE > 2.45V
0 = VDDCORE < 2.45V
bit 5 Unimplemented: Read as ‘0
bit 4 ADSHR: Shared Address SFR Select bit
For details of bit operation, see Register 5-3.
bit 3-1 Unimplemented: Read as ‘0
bit 0 SWDTEN: Software Controlled Watchdog Timer Enable bit(1)
1 = Watchdog Timer is on
0 = Watchdog Timer is off
Note 1: This bit has no effect if the Configuration bit, WDTEN, is enabled.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values
on Page:
RCON IPEN CM RI TO PD POR BOR 56
WDTCON REGSLP LVDSTAT ADSHR —SWDTEN 57
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Watchdog Timer.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 323
PIC18F87J11 FAMILY
24.3 On-Chip Voltage Regulator
All of the PIC18F87J11 family devices power their core
digital logic at a nominal 2.5V. For designs that are
required to operate at a higher typical voltage, such as
3.3V, all devices in the PIC18F87J11 family incorporate
an on-chip regulator that allows the device to run its
core logic from VDD.
The regulator is controlled by the ENVREG pin. Tying
VDD to the pin enables the regulator, which in turn,
provides power to the core from the other VDD pins.
When the regulator is enabled, a low-ESR filter capac-
itor must be connected to the VDDCORE/VCAP pin
(Figure 24-2). This helps to maintain the stability of the
regulator. The recommended value for the filter capac-
itor is provided in Section 27.3 “DC Characteristics:
PIC18F87J11 Family (Industrial)”.
If ENVREG is tied to VSS, the regulator is disabled. In
this case, separate power for the core logic at a nomi-
nal 2.5V must be supplied to the device on the
VDDCORE/VCAP pin to run the I/O pins at higher voltage
levels, typically 3.3V. Alternatively, the VDDCORE/VCAP
and VDD pins can be tied together to operate at a lower
nominal voltage. Refer to Figure 24-2 for possible
configurations.
24.3.1 VOLTAGE REGULATOR TRACKING
MODE AND LOW-VOLTAGE
DETECTION
When it is enabled, the on-chip regulator provides a
constant voltage of 2.5V nominal to the digital core
logic. The regulator can provide this level from a VDD of
about 2.5V, all the way up to the device’s VDDMAX. It
does not have the capability to boost VDD levels below
2.5V. In order to prevent “brown-out” conditions, when
the voltage drops too low for the regulator, the regulator
enters Tracking mode. In Tracking mode, the regulator
output follows VDD, with a typical voltage drop of
100 mV.
The on-chip regulator includes a simple, Low-Voltage
Detect (LVD) circuit. If VDD drops too low to maintain
approximately 2.45V on VDDCORE, the circuit sets the
Low-Voltage Detect Interrupt Flag, LVDIF (PIR2<2>).
This can be used to generate an interrupt and put the
application into a low-power operational mode, or
trigger an orderly shutdown. Low-Voltage Detection is
only available when the regulator is enabled.
The Low-Voltage Detect interrupt is edge-sensitive.
The interrupt flag will only be set once per falling edge
of VDDCORE. Firmware can clear the interrupt flag, but
a new interrupt will not be generated until VDDCORE
rises back above, and then falls below, the 2.45 thresh-
old. Upon device Resets, the interrupt flag will reset to
0’, even if VDDCORE is less than 2.45V. When the
regulator is enabled, the LVDSTAT bit in the WDTCON
register can be polled to determine the current level of
VDDCORE.
FIGURE 24-2: CONNECTIONS FOR THE
ON-CHIP REGULATOR
VDD
ENVREG
VDDCORE/VCAP
VSS
PIC18F87J11
3.3V(1)
2.5V(1)
VDD
ENVREG
VDDCORE/VCAP
VSS
PIC18F87J11
CF
3.3V
Regulator Enabled (ENVREG tied to VDD):
Regulator Disabled (ENVREG tied to ground):
VDD
ENVREG
VDDCORE/VCAP
VSS
PIC18F87J11
2.5V(1)
Regulator Disabled (VDD tied to VDDCORE):
Note 1: These are typical operating voltages. Refer
to Section 27.1 “DC Characteristics:
Supply Voltage” for the full operating
ranges of VDD and VDDCORE.
PIC18F87J11 FAMILY
DS39778C-page 324 Preliminary © 2008 Microchip Technology Inc.
24.3.2 ON-CHIP REGULATOR AND BOR
When the on-chip regulator is enabled, PIC18F87J11
family devices also have a simple brown-out capability.
If the voltage supplied to the regulator is inadequate to
maintain a regulated level, the regulator Reset circuitry
will generate a Brown-out Reset. This event is captured
by the BOR flag bit (RCON<0>).
The operation of the Brown-out Reset is described in
more detail in Section 4.4 “Brown-out Reset (BOR)”
and Section 4.4.1 “Detecting BOR”. The brown-out
voltage levels are specific in Section 27.1 “DC Char-
acteristics: Supply Voltage PIC18F87J11 Family
(Industrial)”.
24.3.3 POWER-UP REQUIREMENTS
The on-chip regulator is designed to meet the power-up
requirements for the device. If the application does not
use the regulator, then strict power-up conditions must
be adhered to. While powering up, VDDCORE must
never exceed VDD by 0.3 volts.
24.3.4 OPERATION IN SLEEP MODE
When enabled, the on-chip regulator always consumes
a small incremental amount of current over IDD. This
includes when the device is in Sleep mode, even
though the core digital logic does not require power. To
provide additional savings in applications where power
resources are critical, the regulator can be configured
to automatically disable itself whenever the device
goes into Sleep mode. This feature is controlled by the
REGSLP bit (WDTCON<7>, Register 24-9). Setting
this bit disables the regulator in Sleep mode and
reduces its current consumption to a minimum.
Substantial Sleep mode power savings can be obtained
by setting the REGSLP bit, but device wake-up time will
increase in order to insure the regulator has enough time
to stabilize. The REGSLP bit is automatically cleared by
hardware when a Low-Voltage Detect condition occurs.
24.4 Two-Speed Start-up
The Two-Speed Start-up feature helps to minimize the
latency period, from oscillator start-up to code execu-
tion, by allowing the microcontroller to use the INTRC
oscillator as a clock source until the primary clock
source is available. It is enabled by setting the IESO
Configuration bit.
Two-Speed Start-up should be enabled only if the
primary oscillator mode is HS or HSPLL
(Crystal-Based) modes. Since the EC and ECPLL
modes do not require an Oscillator Start-up Timer
delay, Two-Speed Start-up should be disabled.
When enabled, Resets and wake-ups from Sleep mode
cause the device to configure itself to run from the inter-
nal oscillator block as the clock source, following the
time-out of the Power-up Timer after a Power-on Reset
is enabled. This allows almost immediate code
execution while the primary oscillator starts and the
OST is running. Once the OST times out, the device
automatically switches to PRI_RUN mode.
In all other power-managed modes, Two-Speed
Start-up is not used. The device will be clocked by the
currently selected clock source until the primary clock
source becomes available. The setting of the IESO bit
is ignored.
FIGURE 24-3: TIMING TRANSITION FOR TWO-SPEED START-UP (INTRC TO HSPLL)
Q1 Q3 Q4
OSC1
Peripheral
Program PC PC + 2
INTRC
PLL Clock
Q1
PC + 6
Q2
Output
Q3 Q4 Q1
CPU Clock
PC + 4
Clock
Counter
Q2 Q2 Q3
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
Wake from Interrupt Event
TPLL(1)
12 n-1n
Clock
OSTS bit Set
Transition
TOST(1)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 325
PIC18F87J11 FAMILY
24.4.1 SPECIAL CONSIDERATIONS FOR
USING TWO-SPEED START-UP
While using the INTRC oscillator in Two-Speed
Start-up, the device still obeys the normal command
sequences for entering power-managed modes,
including serial SLEEP instructions (refer to
Section 3.1.4 “Multiple Sleep Commands”). In prac-
tice, this means that user code can change the
SCS1:SCS0 bit settings or issue SLEEP instructions
before the OST times out. This would allow an applica-
tion to briefly wake-up, perform routine “housekeeping”
tasks and return to Sleep before the device starts to
operate from the primary oscillator.
User code can also check if the primary clock source is
currently providing the device clocking by checking the
status of the OSTS bit (OSCCON<3>). If the bit is set,
the primary oscillator is providing the clock. Otherwise,
the internal oscillator block is providing the clock during
wake-up from Reset or Sleep mode.
24.5 Fail-Safe Clock Monitor
The Fail-Safe Clock Monitor (FSCM) allows the
microcontroller to continue operation in the event of an
external oscillator failure by automatically switching the
device clock to the internal oscillator block. The FSCM
function is enabled by setting the FCMEN Configuration
bit.
When FSCM is enabled, the INTRC oscillator runs at
all times to monitor clocks to peripherals and provide a
backup clock in the event of a clock failure. Clock
monitoring (shown in Figure 24-4) is accomplished by
creating a sample clock signal which is the INTRC out-
put divided by 64. This allows ample time between
FSCM sample clocks for a peripheral clock edge to
occur. The peripheral device clock and the sample
clock are presented as inputs to the Clock Monitor
(CM) latch. The CM is set on the falling edge of the
device clock source but cleared on the rising edge of
the sample clock.
FIGURE 24-4: FSCM BLOCK DIAGRAM
Clock failure is tested for on the falling edge of the
sample clock. If a sample clock falling edge occurs
while CM is still set, a clock failure has been detected
(Figure 24-5). This causes the following:
the FSCM generates an oscillator fail interrupt by
setting bit OSCFIF (PIR2<7>);
the device clock source is switched to the internal
oscillator block (OSCCON is not updated to show
the current clock source – this is the fail-safe
condition); and
the WDT is reset.
During switchover, the postscaler frequency from the
internal oscillator block may not be sufficiently stable
for timing sensitive applications. In these cases, it may
be desirable to select another clock configuration and
enter an alternate power-managed mode. This can be
done to attempt a partial recovery or execute a
controlled shutdown. See Section 3.1.4 “Multiple
Sleep Commands” and Section 24.4.1 “Special
Considerations for Using Two-Speed Start-up” for
more details.
The FSCM will detect failures of the primary or second-
ary clock sources only. If the internal oscillator block
fails, no failure would be detected, nor would any action
be possible.
24.5.1 FSCM AND THE WATCHDOG TIMER
Both the FSCM and the WDT are clocked by the
INTRC oscillator. Since the WDT operates with a
separate divider and counter, disabling the WDT has
no effect on the operation of the INTRC oscillator when
the FSCM is enabled.
As already noted, the clock source is switched to the
INTRC clock when a clock failure is detected; this may
mean a substantial change in the speed of code execu-
tion. If the WDT is enabled with a small prescale value,
a decrease in clock speed allows a WDT time-out to
occur and a subsequent device Reset. For this reason,
fail-safe clock events also reset the WDT and
postscaler, allowing it to start timing from when execu-
tion speed was changed and decreasing the likelihood
of an erroneous time-out.
Peripheral
INTRC ÷ 64
S
C
Q
(32 μs) 488 Hz
(2.048 ms)
Clock Monitor
Latch (CM)
(edge-triggered)
Clock
Failure
Detected
Source
Clock
Q
PIC18F87J11 FAMILY
DS39778C-page 326 Preliminary © 2008 Microchip Technology Inc.
FIGURE 24-5: FSCM TIMING DIAGRAM
24.5.2 EXITING FAIL-SAFE OPERATION
The fail-safe condition is terminated by either a device
Reset or by entering a power-managed mode. On
Reset, the controller starts the primary clock source
specified in Configuration Register 2H (with any
required start-up delays that are required for the oscil-
lator mode, such as OST or PLL timer). The INTRC
oscillator provides the device clock until the primary
clock source becomes ready (similar to a Two-Speed
Start-up). The clock source is then switched to the
primary clock (indicated by the OSTS bit in the
OSCCON register becoming set). The Fail-Safe Clock
Monitor then resumes monitoring the peripheral clock.
The primary clock source may never become ready
during start-up. In this case, operation is clocked by the
INTRC oscillator. The OSCCON register will remain in
its Reset state until a power-managed mode is entered.
24.5.3 FSCM INTERRUPTS IN
POWER-MANAGED MODES
By entering a power-managed mode, the clock
multiplexor selects the clock source selected by the
OSCCON register. Fail-Safe Clock Monitoring of the
power-managed clock source resumes in the
power-managed mode.
If an oscillator failure occurs during power-managed
operation, the subsequent events depend on whether
or not the oscillator failure interrupt is enabled. If
enabled (OSCFIF = 1), code execution will be clocked
by the INTRC multiplexor. An automatic transition back
to the failed clock source will not occur.
If the interrupt is disabled, subsequent interrupts while
in Idle mode will cause the CPU to begin executing
instructions while being clocked by the INTRC source.
24.5.4 POR OR WAKE-UP FROM SLEEP
The FSCM is designed to detect oscillator failure at any
point after the device has exited Power-on Reset (POR)
or low-power Sleep mode. When the primary device
clock is either the EC or INTRC modes, monitoring can
begin immediately following these events.
For HS or HSPLL modes, the situation is somewhat
different. Since the oscillator may require a start-up
time considerably longer than the FSCM sample clock
time, a false clock failure may be detected. To prevent
this, the internal oscillator block is automatically config-
ured as the device clock and functions until the primary
clock is stable (the OST and PLL timers have timed
out). This is identical to Two-Speed Start-up mode.
Once the primary clock is stable, the INTRC returns to
its role as the FSCM source.
As noted in Section 24.4.1 “Special Considerations
for Using Two-Speed Start-up”, it is also possible to
select another clock configuration and enter an alternate
power-managed mode while waiting for the primary
clock to become stable. When the new power-managed
mode is selected, the primary clock is disabled.
OSCFIF
CM Output
Device
Clock
Output
Sample Clock
Failure
Detected
Oscillator
Failure
Note: The device clock is normally at a much higher frequency than the sample clock. The relative frequencies in
this example have been chosen for clarity.
(Q)
CM Test CM Test CM Test
Note: The same logic that prevents false
oscillator failure interrupts on POR, or
wake from Sleep, will also prevent the
detection of the oscillator’s failure to start
at all following these events. This can be
avoided by monitoring the OSTS bit and
using a timing routine to determine if the
oscillator is taking too long to start. Even
so, no oscillator failure interrupt will be
flagged.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 327
PIC18F87J11 FAMILY
24.6 Program Verification and
Code Protection
For all devices in the PIC18F87J11 Family of devices,
the on-chip program memory space is treated as a
single block. Code protection for this block is controlled
by one Configuration bit, CP0. This bit inhibits external
reads and writes to the program memory space. It has
no direct effect in normal execution mode.
24.6.1 CONFIGURATION REGISTER
PROTECTION
The Configuration registers are protected against
untoward changes or reads in two ways. The primary
protection is the write-once feature of the Configuration
bits which prevents reconfiguration once the bit has
been programmed during a power cycle. To safeguard
against unpredictable events, Configuration bit
changes resulting from individual cell level disruptions
(such as ESD events) will cause a parity error and
trigger a device Reset. This is seen by the user as a
Configuration Match Reset.
The data for the Configuration registers is derived from
the Flash Configuration Words in program memory.
When the CP0 bit set, the source data for device
configuration is also protected as a consequence.
24.7 In-Circuit Serial Programming
PIC18F87J11 Family microcontrollers can be serially
programmed while in the end application circuit. This is
simply done with two lines for clock and data and three
other lines for power, ground and the programming
voltage. This allows customers to manufacture boards
with unprogrammed devices and then program the
microcontroller just before shipping the product. This
also allows the most recent firmware or a custom
firmware to be programmed.
24.8 In-Circuit Debugger
When the DEBUG Configuration bit is programmed to
a ‘0’, the In-Circuit Debugger functionality is enabled.
This function allows simple debugging functions when
used with MPLAB® IDE. When the microcontroller has
this feature enabled, some resources are not available
for general use. Table 24-4 shows which resources are
required by the background debugger.
TABLE 24-4: DEBUGGER RESOURCES
I/O pins: RB6, RB7
Stack: 2 levels
Program Memory: 512 bytes
Data Memory: 10 bytes
PIC18F87J11 FAMILY
DS39778C-page 328 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 329
PIC18F87J11 FAMILY
25.0 INSTRUCTION SET SUMMARY
The PIC18F87J11 Family of devices incorporate the
standard set of 75 PIC18 core instructions, as well as
an extended set of 8 new instructions for the optimiza-
tion of code that is recursive or that utilizes a software
stack. The extended set is discussed later in this
section.
25.1 Standard Instruction Set
The standard PIC18 instruction set adds many
enhancements to the previous PIC® instruction sets,
while maintaining an easy migration from these instruc-
tion sets. Most instructions are a single program
memory word (16 bits), but there are four instructions
that require two program memory locations.
Each single-word instruction is a 16-bit word divided
into an opcode, which specifies the instruction type and
one or more operands, which further specify the
operation of the instruction.
The instruction set is highly orthogonal and is grouped
into four basic categories:
Byte-oriented operations
Bit-oriented operations
Literal operations
Control operations
The PIC18 instruction set summary in Table 25-2 lists
byte-oriented, bit-oriented, literal and control
operations. Table 25-1 shows the opcode field
descriptions.
Most byte-oriented instructions have three operands:
1. The file register (specified by ‘f’)
2. The destination of the result (specified by ‘d’)
3. The accessed memory (specified by ‘a’)
The file register designator, ‘f’, specifies which file reg-
ister is to be used by the instruction. The destination
designator, ‘d’, specifies where the result of the
operation is to be placed. If ‘d’ is ‘0’, the result is placed
in the WREG register. If ‘d’ is ‘1, the result is placed in
the file register specified in the instruction.
All bit-oriented instructions have three operands:
1. The file register (specified by ‘f’)
2. The bit in the file register (specified by ‘b’)
3. The accessed memory (specified by ‘a’)
The bit field designator ‘b’ selects the number of the bit
affected by the operation, while the file register desig-
nator, ‘f’, represents the number of the file in which the
bit is located.
The literal instructions may use some of the following
operands:
A literal value to be loaded into a file register
(specified by ‘k’)
The desired FSR register to load the literal value
into (specified by ‘f’)
No operand required
(specified by ‘—’)
The control instructions may use some of the following
operands:
A program memory address (specified by ‘n’)
The mode of the CALL or RETURN instructions
(specified by ‘s’)
The mode of the table read and table write
instructions (specified by ‘m’)
No operand required
(specified by ‘—’)
All instructions are a single word, except for four
double-word instructions. These instructions were
made double-word to contain the required information
in 32 bits. In the second word, the 4 MSbs are ‘1s. If
this second word is executed as an instruction (by
itself), it will execute as a NOP.
All single-word instructions are executed in a single
instruction cycle, unless a conditional test is true or the
program counter is changed as a result of the instruc-
tion. In these cases, the execution takes two instruction
cycles with the additional instruction cycle(s) executed
as a NOP.
The double-word instructions execute in two instruction
cycles.
One instruction cycle consists of four oscillator periods.
Thus, for an oscillator frequency of 4 MHz, the normal
instruction execution time is 1 μs. If a conditional test is
true, or the program counter is changed as a result of
an instruction, the instruction execution time is 2 μs.
Two-word branch instructions (if true) would take 3 μs.
Figure 25-1 shows the general formats that the instruc-
tions can have. All examples use the convention ‘nnh’
to represent a hexadecimal number.
The instruction set summary, shown in Table 25-2, lists
the standard instructions recognized by the Microchip
MPASMTM Assembler.
Section 25.1.1 “Standard Instruction Set” provides
a description of each instruction.
PIC18F87J11 FAMILY
DS39778C-page 330 Preliminary © 2008 Microchip Technology Inc.
TABLE 25-1: OPCODE FIELD DESCRIPTIONS
Field Description
aRAM access bit:
a = 0: RAM location in Access RAM (BSR register is ignored)
a = 1: RAM bank is specified by BSR register
bbb Bit address within an 8-bit file register (0 to 7).
BSR Bank Select Register. Used to select the current RAM bank.
C, DC, Z, OV, N ALU Status bits: Carry, Digit Carry, Zero, Overflow, Negative.
dDestination select bit:
d = 0: store result in WREG
d = 1: store result in file register f
dest Destination: either the WREG register or the specified register file location.
f8-bit register file address (00h to FFh), or 2-bit FSR designator (0h to 3h).
fs12-bit register file address (000h to FFFh). This is the source address.
fd12-bit register file address (000h to FFFh). This is the destination address.
GIE Global Interrupt Enable bit.
kLiteral field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value).
label Label name.
mm The mode of the TBLPTR register for the table read and table write instructions.
Only used with table read and table write instructions:
*No Change to register (such as TBLPTR with table reads and writes)
*+ Post-Increment register (such as TBLPTR with table reads and writes)
*- Post-Decrement register (such as TBLPTR with table reads and writes)
+* Pre-Increment register (such as TBLPTR with table reads and writes)
nThe relative address (2’s complement number) for relative branch instructions or the direct address for
Call/Branch and Return instructions.
PC Program Counter.
PCL Program Counter Low Byte.
PCH Program Counter High Byte.
PCLATH Program Counter High Byte Latch.
PCLATU Program Counter Upper Byte Latch.
PD Power-Down bit.
PRODH Product of Multiply High Byte.
PRODL Product of Multiply Low Byte.
sFast Call/Return mode select bit:
s = 0: do not update into/from shadow registers
s = 1: certain registers loaded into/from shadow registers (Fast mode)
TBLPTR 21-bit Table Pointer (points to a program memory location).
TABLAT 8-bit Table Latch.
TO Time-out bit.
TOS Top-of-Stack.
uUnused or Unchanged.
WDT Watchdog Timer.
WREG Working register (accumulator).
xDon’t care (‘0’ or ‘1’). The assembler will generate code with x = 0. It is the recommended form of use for
compatibility with all Microchip software tools.
zs7-bit offset value for Indirect Addressing of register files (source).
zd7-bit offset value for Indirect Addressing of register files (destination).
{ } Optional argument.
[text] Indicates Indexed Addressing.
(text) The contents of text.
[expr]<n> Specifies bit n of the register indicated by the pointer, expr.
Assigned to.
< > Register bit field.
In the set of.
italics User-defined term (font is Courier New).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 331
PIC18F87J11 FAMILY
FIGURE 25-1: GENERAL FORMAT FOR INSTRUCTIONS
Byte-oriented file register operations
15 10 9 8 7 0
d = 0 for result destination to be WREG register
OPCODE d a f (FILE #)
d = 1 for result destination to be file register (f)
a = 0 to force Access Bank
Bit-oriented file register operations
15 12 11 9 8 7 0
OPCODE b (BIT #) a f (FILE #)
b = 3-bit position of bit in file register (f)
Literal operations
15 8 7 0
OPCODE k (literal)
k = 8-bit immediate value
Byte to Byte move operations (2-word)
15 12 11 0
OPCODE f (Source FILE #)
CALL, GOTO and Branch operations
15 8 7 0
OPCODE n<7:0> (literal)
n = 20-bit immediate value
a = 1 for BSR to select bank
f = 8-bit file register address
a = 0 to force Access Bank
a = 1 for BSR to select bank
f = 8-bit file register address
15 12 11 0
1111 n<19:8> (literal)
15 12 11 0
1111 f (Destination FILE #)
f = 12-bit file register address
Control operations
Example Instruction
ADDWF MYREG, W, B
MOVFF MYREG1, MYREG2
BSF MYREG, bit, B
MOVLW 7Fh
GOTO Label
15 8 7 0
OPCODE n<7:0> (literal)
15 12 11 0
1111 n<19:8> (literal)
CALL MYFUNC
15 11 10 0
OPCODE n<10:0> (literal)
S = Fast bit
BRA MYFUNC
15 8 7 0
OPCODE n<7:0> (literal) BC MYFUNC
S
PIC18F87J11 FAMILY
DS39778C-page 332 Preliminary © 2008 Microchip Technology Inc.
TABLE 25-2: PIC18F87J11 FAMILY INSTRUCTION SET
Mnemonic,
Operands Description Cycles
16-Bit Instruction Word Status
Affected Notes
MSb LSb
BYTE-ORIENTED OPERATIONS
ADDWF
ADDWFC
ANDWF
CLRF
COMF
CPFSEQ
CPFSGT
CPFSLT
DECF
DECFSZ
DCFSNZ
INCF
INCFSZ
INFSNZ
IORWF
MOVF
MOVFF
MOVWF
MULWF
NEGF
RLCF
RLNCF
RRCF
RRNCF
SETF
SUBFWB
SUBWF
SUBWFB
SWAPF
TSTFSZ
XORWF
f, d, a
f, d, a
f, d, a
f, a
f, d, a
f, a
f, a
f, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
fs, fd
f, a
f, a
f, a
f, d, a
f, d, a
f, d, a
f, d, a
f, a
f, d, a
f, d, a
f, d, a
f, d, a
f, a
f, d, a
Add WREG and f
Add WREG and Carry bit to f
AND WREG with f
Clear f
Complement f
Compare f with WREG, Skip =
Compare f with WREG, Skip >
Compare f with WREG, Skip <
Decrement f
Decrement f, Skip if 0
Decrement f, Skip if Not 0
Increment f
Increment f, Skip if 0
Increment f, Skip if Not 0
Inclusive OR WREG with f
Move f
Move fs (source) to 1st word
fd (destination) 2nd word
Move WREG to f
Multiply WREG with f
Negate f
Rotate Left f through Carry
Rotate Left f (No Carry)
Rotate Right f through Carry
Rotate Right f (No Carry)
Set f
Subtract f from WREG with
Borrow
Subtract WREG from f
Subtract WREG from f with
Borrow
Swap Nibbles in f
Test f, Skip if 0
Exclusive OR WREG with f
1
1
1
1
1
1 (2 or 3)
1 (2 or 3)
1 (2 or 3)
1
1 (2 or 3)
1 (2 or 3)
1
1 (2 or 3)
1 (2 or 3)
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1 (2 or 3)
1
0010
0010
0001
0110
0001
0110
0110
0110
0000
0010
0100
0010
0011
0100
0001
0101
1100
1111
0110
0000
0110
0011
0100
0011
0100
0110
0101
0101
0101
0011
0110
0001
01da
00da
01da
101a
11da
001a
010a
000a
01da
11da
11da
10da
11da
10da
00da
00da
ffff
ffff
111a
001a
110a
01da
01da
00da
00da
100a
01da
11da
10da
10da
011a
10da
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
C, DC, Z, OV, N
C, DC, Z, OV, N
Z, N
Z
Z, N
None
None
None
C, DC, Z, OV, N
None
None
C, DC, Z, OV, N
None
None
Z, N
Z, N
None
None
None
C, DC, Z, OV, N
C, Z, N
Z, N
C, Z, N
Z, N
None
C, DC, Z, OV, N
C, DC, Z, OV, N
C, DC, Z, OV, N
None
None
Z, N
1, 2
1, 2
1,2
2
1, 2
4
4
1, 2
1, 2, 3, 4
1, 2, 3, 4
1, 2
1, 2, 3, 4
4
1, 2
1, 2
1
1, 2
1, 2
1, 2
1, 2
4
1, 2
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be
that value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input
and is driven low by an external device, the data will be written back with a ‘0’.
2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be
cleared if assigned.
3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The
second cycle is executed as a NOP.
4: Some instructions are two-word instructions. The second word of these instructions will be executed as a
NOP unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures
that all program memory locations have a valid instruction.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 333
PIC18F87J11 FAMILY
BIT-ORIENTED OPERATIONS
BCF
BSF
BTFSC
BTFSS
BTG
f, b, a
f, b, a
f, b, a
f, b, a
f, b, a
Bit Clear f
Bit Set f
Bit Test f, Skip if Clear
Bit Test f, Skip if Set
Bit Toggle f
1
1
1 (2 or 3)
1 (2 or 3)
1
1001
1000
1011
1010
0111
bbba
bbba
bbba
bbba
bbba
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
None
None
None
None
None
1, 2
1, 2
3, 4
3, 4
1, 2
CONTROL OPERATIONS
BC
BN
BNC
BNN
BNOV
BNZ
BOV
BRA
BZ
CALL
CLRWDT
DAW
GOTO
NOP
NOP
POP
PUSH
RCALL
RESET
RETFIE
RETLW
RETURN
SLEEP
n
n
n
n
n
n
n
n
n
n, s
n
n
s
k
s
Branch if Carry
Branch if Negative
Branch if Not Carry
Branch if Not Negative
Branch if Not Overflow
Branch if Not Zero
Branch if Overflow
Branch Unconditionally
Branch if Zero
Call Subroutine 1st word
2nd word
Clear Watchdog Timer
Decimal Adjust WREG
Go to Address 1st word
2nd word
No Operation
No Operation
Pop Top of Return Stack (TOS)
Push Top of Return Stack (TOS)
Relative Call
Software Device Reset
Return from Interrupt Enable
Return with Literal in WREG
Return from Subroutine
Go into Standby mode
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
2
1 (2)
2
1
1
2
1
1
1
1
2
1
2
2
2
1
1110
1110
1110
1110
1110
1110
1110
1101
1110
1110
1111
0000
0000
1110
1111
0000
1111
0000
0000
1101
0000
0000
0000
0000
0000
0010
0110
0011
0111
0101
0001
0100
0nnn
0000
110s
kkkk
0000
0000
1111
kkkk
0000
xxxx
0000
0000
1nnn
0000
0000
1100
0000
0000
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
kkkk
kkkk
0000
0000
kkkk
kkkk
0000
xxxx
0000
0000
nnnn
1111
0001
kkkk
0001
0000
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
kkkk
kkkk
0100
0111
kkkk
kkkk
0000
xxxx
0110
0101
nnnn
1111
000s
kkkk
001s
0011
None
None
None
None
None
None
None
None
None
None
TO, PD
C
None
None
None
None
None
None
All
GIE/GIEH,
PEIE/GIEL
None
None
TO, PD
4
TABLE 25-2: PIC18F87J11 FAMILY INSTRUCTION SET (CONTINUED)
Mnemonic,
Operands Description Cycles
16-Bit Instruction Word Status
Affected Notes
MSb LSb
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be
that value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input
and is driven low by an external device, the data will be written back with a ‘0’.
2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be
cleared if assigned.
3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The
second cycle is executed as a NOP.
4: Some instructions are two-word instructions. The second word of these instructions will be executed as a
NOP unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures
that all program memory locations have a valid instruction.
PIC18F87J11 FAMILY
DS39778C-page 334 Preliminary © 2008 Microchip Technology Inc.
LITERAL OPERATIONS
ADDLW
ANDLW
IORLW
LFSR
MOVLB
MOVLW
MULLW
RETLW
SUBLW
XORLW
k
k
k
f, k
k
k
k
k
k
k
Add Literal and WREG
AND Literal with WREG
Inclusive OR Literal with WREG
Move Literal (12-bit) 2nd word
to FSR (f) 1st word
Move Literal to BSR<3:0>
Move Literal to WREG
Multiply Literal with WREG
Return with Literal in WREG
Subtract WREG from Literal
Exclusive OR Literal with WREG
1
1
1
2
1
1
1
2
1
1
0000
0000
0000
1110
1111
0000
0000
0000
0000
0000
0000
1111
1011
1001
1110
0000
0001
1110
1101
1100
1000
1010
kkkk
kkkk
kkkk
00ff
kkkk
0000
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
C, DC, Z, OV, N
Z, N
Z, N
None
None
None
None
None
C, DC, Z, OV, N
Z, N
DATA MEMORY PROGRAM MEMORY OPERATIONS
TBLRD*
TBLRD*+
TBLRD*-
TBLRD+*
TBLWT*
TBLWT*+
TBLWT*-
TBLWT+*
Table Read
Table Read with Post-Increment
Table Read with Post-Decrement
Table Read with Pre-Increment
Table Write
Table Write with Post-Increment
Table Write with Post-Decrement
Table Write with Pre-Increment
2
2
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
1000
1001
1010
1011
1100
1101
1110
1111
None
None
None
None
None
None
None
None
TABLE 25-2: PIC18F87J11 FAMILY INSTRUCTION SET (CONTINUED)
Mnemonic,
Operands Description Cycles
16-Bit Instruction Word Status
Affected Notes
MSb LSb
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be
that value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input
and is driven low by an external device, the data will be written back with a ‘0’.
2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be
cleared if assigned.
3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The
second cycle is executed as a NOP.
4: Some instructions are two-word instructions. The second word of these instructions will be executed as a
NOP unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures
that all program memory locations have a valid instruction.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 335
PIC18F87J11 FAMILY
25.1.1 STANDARD INSTRUCTION SET
ADDLW ADD Literal to W
Syntax: ADDLW k
Operands: 0 k 255
Operation: (W) + k W
Status Affected: N, OV, C, DC, Z
Encoding: 0000 1111 kkkk kkkk
Description: The contents of W are added to the
8-bit literal ‘k’ and the result is placed in
W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
W
Example: ADDLW 15h
Before Instruction
W = 10h
After Instruction
W = 25h
ADDWF ADD W to f
Syntax: ADDWF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) + (f) dest
Status Affected: N, OV, C, DC, Z
Encoding: 0010 01da ffff ffff
Description: Add W to register ‘f’. If ‘d’ is ‘0’, the
result is stored in W. If ‘d’ is ‘1’, the
result is stored back in register ‘f’
(default).
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: ADDWF REG, 0, 0
Before Instruction
W = 17h
REG = 0C2h
After Instruction
W = 0D9h
REG = 0C2h
Note: All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in
symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s).
PIC18F87J11 FAMILY
DS39778C-page 336 Preliminary © 2008 Microchip Technology Inc.
ADDWFC ADD W and Carry bit to f
Syntax: ADDWFC f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) + (f) + (C) dest
Status Affected: N,OV, C, DC, Z
Encoding: 0010 00da ffff ffff
Description: Add W, the Carry flag and data memory
location ‘f’. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed in data memory location ‘f’.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: ADDWFC REG, 0, 1
Before Instruction
Carry bit = 1
REG = 02h
W=4Dh
After Instruction
Carry bit = 0
REG = 02h
W = 50h
ANDLW AND Literal with W
Syntax: ANDLW k
Operands: 0 k 255
Operation: (W) .AND. k W
Status Affected: N, Z
Encoding: 0000 1011 kkkk kkkk
Description: The contents of W are ANDed with the
8-bit literal ‘k’. The result is placed in W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘k’
Process
Data
Write to
W
Example: ANDLW 05Fh
Before Instruction
W=A3h
After Instruction
W = 03h
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 337
PIC18F87J11 FAMILY
ANDWF AND W with f
Syntax: ANDWF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) .AND. (f) dest
Status Affected: N, Z
Encoding: 0001 01da ffff ffff
Description: The contents of W are ANDed with
register ‘f’. If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is ‘1’, the result is stored back
in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: ANDWF REG, 0, 0
Before Instruction
W = 17h
REG = C2h
After Instruction
W = 02h
REG = C2h
BC Branch if Carry
Syntax: BC n
Operands: -128 n 127
Operation: if Carry bit is ‘1’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0010 nnnn nnnn
Description: If the Carry bit is ’1’, then the program
will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BC 5
Before Instruction
PC = address (HERE)
After Instruction
If Carry = 1;
PC = address (HERE + 12)
If Carry = 0;
PC = address (HERE + 2)
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BCF Bit Clear f
Syntax: BCF f, b {,a}
Operands: 0 f 255
0 b 7
a [0,1]
Operation: 0 f<b>
Status Affected: None
Encoding: 1001 bbba ffff ffff
Description: Bit ‘b’ in register ‘f’ is cleared.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: BCF FLAG_REG, 7, 0
Before Instruction
FLAG_REG = C7h
After Instruction
FLAG_REG = 47h
BN Branch if Negative
Syntax: BN n
Operands: -128 n 127
Operation: if Negative bit is ‘1’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0110 nnnn nnnn
Description: If the Negative bit is ‘1’, then the
program will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BN Jump
Before Instruction
PC = address (HERE)
After Instruction
If Negative = 1;
PC = address (Jump)
If Negative = 0;
PC = address (HERE + 2)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 339
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BNC Branch if Not Carry
Syntax: BNC n
Operands: -128 n 127
Operation: if Carry bit is ‘0’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0011 nnnn nnnn
Description: If the Carry bit is ‘0’, then the program
will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BNC Jump
Before Instruction
PC = address (HERE)
After Instruction
If Carry = 0;
PC = address (Jump)
If Carry = 1;
PC = address (HERE + 2)
BNN Branch if Not Negative
Syntax: BNN n
Operands: -128 n 127
Operation: if Negative bit is ‘0’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0111 nnnn nnnn
Description: If the Negative bit is ‘0’, then the
program will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BNN Jump
Before Instruction
PC = address (HERE)
After Instruction
If Negative = 0;
PC = address (Jump)
If Negative = 1;
PC = address (HERE + 2)
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BNOV Branch if Not Overflow
Syntax: BNOV n
Operands: -128 n 127
Operation: if Overflow bit is ‘0’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0101 nnnn nnnn
Description: If the Overflow bit is ‘0’, then the
program will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BNOV Jump
Before Instruction
PC = address (HERE)
After Instruction
If Overflow = 0;
PC = address (Jump)
If Overflow = 1;
PC = address (HERE + 2)
BNZ Branch if Not Zero
Syntax: BNZ n
Operands: -128 n 127
Operation: if Zero bit is ‘0’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0001 nnnn nnnn
Description: If the Zero bit is ‘0’, then the program
will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BNZ Jump
Before Instruction
PC = address (HERE)
After Instruction
If Zero = 0;
PC = address (Jump)
If Zero = 1;
PC = address (HERE + 2)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 341
PIC18F87J11 FAMILY
BRA Unconditional Branch
Syntax: BRA n
Operands: -1024 n 1023
Operation: (PC) + 2 + 2n PC
Status Affected: None
Encoding: 1101 0nnn nnnn nnnn
Description: Add the 2’s complement number ‘2n’ to
the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is a
two-cycle instruction.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
Example: HERE BRA Jump
Before Instruction
PC = address (HERE)
After Instruction
PC = address (Jump)
BSF Bit Set f
Syntax: BSF f, b {,a}
Operands: 0 f 255
0 b 7
a [0,1]
Operation: 1 f<b>
Status Affected: None
Encoding: 1000 bbba ffff ffff
Description: Bit ‘b’ in register ‘f’ is set.
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: BSF FLAG_REG, 7, 1
Before Instruction
FLAG_REG = 0Ah
After Instruction
FLAG_REG = 8Ah
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BTFSC Bit Test File, Skip if Clear
Syntax: BTFSC f, b {,a}
Operands: 0 f 255
0 b 7
a [0,1]
Operation: skip if (f<b>) = 0
Status Affected: None
Encoding: 1011 bbba ffff ffff
Description: If bit ‘b’ in register ‘f’ is ‘0’, then the next
instruction is skipped. If bit ‘b’ is 0’, then
the next instruction fetched during the
current instruction execution is discarded
and a NOP is executed instead, making
this a two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction set
is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE
FALSE
TRUE
BTFSC
:
:
FLAG, 1, 0
Before Instruction
PC = address (HERE)
After Instruction
If FLAG<1> = 0;
PC = address (TRUE)
If FLAG<1> = 1;
PC = address (FALSE)
BTFSS Bit Test File, Skip if Set
Syntax: BTFSS f, b {,a}
Operands: 0 f 255
0 b < 7
a [0,1]
Operation: skip if (f<b>) = 1
Status Affected: None
Encoding: 1010 bbba ffff ffff
Description: If bit ‘b’ in register ‘f’ is 1’, then the next
instruction is skipped. If bit ‘b’ is ‘1’, then
the next instruction fetched during the
current instruction execution is discarded
and a NOP is executed instead, making
this a two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE
FALSE
TRUE
BTFSS
:
:
FLAG, 1, 0
Before Instruction
PC = address (HERE)
After Instruction
If FLAG<1> = 0;
PC = address (FALSE)
If FLAG<1> = 1;
PC = address (TRUE)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 343
PIC18F87J11 FAMILY
BTG Bit Toggle f
Syntax: BTG f, b {,a}
Operands: 0 f 255
0 b < 7
a [0,1]
Operation: (f<b>) f<b>
Status Affected: None
Encoding: 0111 bbba ffff ffff
Description: Bit ‘b’ in data memory location ‘f’ is
inverted.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: BTG PORTC, 4, 0
Before Instruction:
PORTC = 0111 0101 [75h]
After Instruction:
PORTC = 0110 0101 [65h]
BOV Branch if Overflow
Syntax: BOV n
Operands: -128 n 127
Operation: if Overflow bit is ‘1’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0100 nnnn nnnn
Description: If the Overflow bit is ‘1’, then the
program will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BOV Jump
Before Instruction
PC = address (HERE)
After Instruction
If Overflow = 1;
PC = address (Jump)
If Overflow = 0;
PC = address (HERE + 2)
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BZ Branch if Zero
Syntax: BZ n
Operands: -128 n 127
Operation: if Zero bit is ‘1’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0000 nnnn nnnn
Description: If the Zero bit is ‘1’, then the program
will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BZ Jump
Before Instruction
PC = address (HERE)
After Instruction
If Zero = 1;
PC = address (Jump)
If Zero = 0;
PC = address (HERE + 2)
CALL Subroutine Call
Syntax: CALL k {,s}
Operands: 0 k 1048575
s [0,1]
Operation: (PC) + 4 TOS,
k PC<20:1>;
if s = 1,
(W) WS,
(STATUS) STATUSS,
(BSR) BSRS
Status Affected: None
Encoding:
1st word (k<7:0>)
2nd word(k<19:8>)
1110
1111
110s
k19kkk
k7kkk
kkkk
kkkk0
kkkk8
Description: Subroutine call of entire 2-Mbyte
memory range. First, return address
(PC + 4) is pushed onto the return
stack. If ‘s’ = 1, the W, STATUS and
BSR registers are also pushed into their
respective shadow registers, WS,
STATUSS and BSRS. If ‘s’ = 0, no
update occurs (default). Then, the
20-bit value ‘k’ is loaded into PC<20:1>.
CALL is a two-cycle instruction.
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘k’<7:0>,
Push PC to
stack
Read literal
’k’<19:8>,
Write to PC
No
operation
No
operation
No
operation
No
operation
Example: HERE CALL THERE,1
Before Instruction
PC = address (HERE)
After Instruction
PC = address (THERE)
TOS = address (HERE + 4)
WS = W
BSRS = BSR
STATUSS = STATUS
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 345
PIC18F87J11 FAMILY
CLRF Clear f
Syntax: CLRF f {,a}
Operands: 0 f 255
a [0,1]
Operation: 000h f,
1 Z
Status Affected: Z
Encoding: 0110 101a ffff ffff
Description: Clears the contents of the specified
register.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: CLRF FLAG_REG,1
Before Instruction
FLAG_REG = 5Ah
After Instruction
FLAG_REG = 00h
CLRWDT Clear Watchdog Timer
Syntax: CLRWDT
Operands: None
Operation: 000h WDT,
000h WDT postscaler,
1 TO,
1 PD
Status Affected: TO, PD
Encoding: 0000 0000 0000 0100
Description: CLRWDT instruction resets the
Watchdog Timer. It also resets the
postscaler of the WDT. Status bits, TO
and PD, are set.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
Process
Data
No
operation
Example: CLRWDT
Before Instruction
WDT Counter = ?
After Instruction
WDT Counter = 00h
WDT Postscaler = 0
TO =1
PD =1
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COMF Complement f
Syntax: COMF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: f dest
Status Affected: N, Z
Encoding: 0001 11da ffff ffff
Description: The contents of register ‘f’ are
complemented. If ‘d’ is ‘0’, the result is
stored in W. If ‘d’ is ‘1’, the result is
stored back in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: COMF REG, 0, 0
Before Instruction
REG = 13h
After Instruction
REG = 13h
W=ECh
CPFSEQ Compare f with W, Skip if f = W
Syntax: CPFSEQ f {,a}
Operands: 0 f 255
a [0,1]
Operation: (f) – (W),
skip if (f) = (W)
(unsigned comparison)
Status Affected: None
Encoding: 0110 001a ffff ffff
Description: Compares the contents of data memory
location ‘f’ to the contents of W by
performing an unsigned subtraction.
If ‘f’ = W, then the fetched instruction is
discarded and a NOP is executed
instead, making this a two-cycle
instruction.
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE CPFSEQ REG, 0
NEQUAL :
EQUAL :
Before Instruction
PC Address = HERE
W=?
REG = ?
After Instruction
If REG = W;
PC = Address (EQUAL)
If REG W;
PC = Address (NEQUAL)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 347
PIC18F87J11 FAMILY
CPFSGT Compare f with W, Skip if f > W
Syntax: CPFSGT f {,a}
Operands: 0 f 255
a [0,1]
Operation: (f) – (W),
skip if (f) > (W)
(unsigned comparison)
Status Affected: None
Encoding: 0110 010a ffff ffff
Description: Compares the contents of data memory
location ‘f’ to the contents of the W by
performing an unsigned subtraction.
If the contents of ‘f’ are greater than the
contents of WREG, then the fetched
instruction is discarded and a NOP is
executed instead, making this a
two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE CPFSGT REG, 0
NGREATER :
GREATER :
Before Instruction
PC = Address (HERE)
W= ?
After Instruction
If REG > W;
PC = Address (GREATER)
If REG W;
PC = Address (NGREATER)
CPFSLT Compare f with W, Skip if f < W
Syntax: CPFSLT f {,a}
Operands: 0 f 255
a [0,1]
Operation: (f) – (W),
skip if (f) < (W)
(unsigned comparison)
Status Affected: None
Encoding: 0110 000a ffff ffff
Description: Compares the contents of data memory
location ‘f’ to the contents of W by
performing an unsigned subtraction.
If the contents of ‘f’ are less than the
contents of W, then the fetched
instruction is discarded and a NOP is
executed instead, making this a
two-cycle instruction.
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE CPFSLT REG, 1
NLESS :
LESS :
Before Instruction
PC = Address (HERE)
W= ?
After Instruction
If REG < W;
PC = Address (LESS)
If REG W;
PC = Address (NLESS)
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DAW Decimal Adjust W Register
Syntax: DAW
Operands: None
Operation: If [W<3:0> > 9] or [DC = 1] then,
(W<3:0>) + 6 W<3:0>;
else,
(W<3:0>) W<3:0>
If [W<7:4> > 9] or [C = 1] then,
(W<7:4>) + 6 W<7:4>,
C = 1;
else,
(W<7:4>) W<7:4>
Status Affected: C
Encoding: 0000 0000 0000 0111
Description: DAW adjusts the eight-bit value in W,
resulting from the earlier addition of two
variables (each in packed BCD format)
and produces a correct packed BCD
result.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register W
Process
Data
Write
W
Example 1: DAW
Before Instruction
W=A5h
C=0
DC = 0
After Instruction
W = 05h
C=1
DC = 0
Example 2:
Before Instruction
W=CEh
C=0
DC = 0
After Instruction
W = 34h
C=1
DC = 0
DECF Decrement f
Syntax: DECF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) – 1 dest
Status Affected: C, DC, N, OV, Z
Encoding: 0000 01da ffff ffff
Description: Decrement register ‘f’. If ‘d’ is ‘0’, the
result is stored in W. If ‘d’ is ‘1’, the
result is stored back in register ‘f’
(default).
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: DECF CNT, 1, 0
Before Instruction
CNT = 01h
Z=0
After Instruction
CNT = 00h
Z=1
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 349
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DECFSZ Decrement f, Skip if 0
Syntax: DECFSZ f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) – 1 dest,
skip if result = 0
Status Affected: None
Encoding: 0010 11da ffff ffff
Description: The contents of register ‘f’ are
decremented. If ‘d’ is 0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
If the result is ‘0’, the next instruction
which is already fetched is discarded
and a NOP is executed instead, making
it a two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE DECFSZ CNT, 1, 1
GOTO LOOP
CONTINUE
Before Instruction
PC = Address (HERE)
After Instruction
CNT = CNT – 1
If CNT = 0;
PC = Address (CONTINUE)
If CNT 0;
PC = Address (HERE + 2)
DCFSNZ Decrement f, Skip if not 0
Syntax: DCFSNZ f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) – 1 dest,
skip if result 0
Status Affected: None
Encoding: 0100 11da ffff ffff
Description: The contents of register ‘f’ are
decremented. If ‘d’ is 0’, the result is
placed in W. If ‘d’ is1’, the result is
placed back in register ‘f’ (default).
If the result is not 0’, the next
instruction which is already fetched is
discarded and a NOP is executed
instead, making it a two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE DCFSNZ TEMP, 1, 0
ZERO :
NZERO :
Before Instruction
TEMP = ?
After Instruction
TEMP = TEMP – 1,
If TEMP = 0;
PC = Address (ZERO)
If TEMP 0;
PC = Address (NZERO)
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GOTO Unconditional Branch
Syntax: GOTO k
Operands: 0 k 1048575
Operation: k PC<20:1>
Status Affected: None
Encoding:
1st word (k<7:0>)
2nd word(k<19:8>)
1110
1111
1111
k19kkk
k7kkk
kkkk
kkkk0
kkkk8
Description: GOTO allows an unconditional branch
anywhere within entire 2-Mbyte memory
range. The 20-bit value ‘k’ is loaded into
PC<20:1>. GOTO is always a two-cycle
instruction.
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘k’<7:0>,
No
operation
Read literal
‘k’<19:8>,
Write to PC
No
operation
No
operation
No
operation
No
operation
Example: GOTO THERE
After Instruction
PC = Address (THERE)
INCF Increment f
Syntax: INCF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) + 1 dest
Status Affected: C, DC, N, OV, Z
Encoding: 0010 10da ffff ffff
Description: The contents of register ‘f’ are
incremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: INCF CNT, 1, 0
Before Instruction
CNT = FFh
Z=0
C=?
DC = ?
After Instruction
CNT = 00h
Z=1
C=1
DC = 1
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 351
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INCFSZ Increment f, Skip if 0
Syntax: INCFSZ f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) + 1 dest,
skip if result = 0
Status Affected: None
Encoding: 0011 11da ffff ffff
Description: The contents of register ‘f’ are
incremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’. (default)
If the result is ‘0’, the next instruction
which is already fetched is discarded
and a NOP is executed instead, making
it a two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE INCFSZ CNT, 1, 0
NZERO :
ZERO :
Before Instruction
PC = Address (HERE)
After Instruction
CNT = CNT + 1
If CNT = 0;
PC = Address (ZERO)
If CNT 0;
PC = Address (NZERO)
INFSNZ Increment f, Skip if not 0
Syntax: INFSNZ f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) + 1 dest,
skip if result 0
Status Affected: None
Encoding: 0100 10da ffff ffff
Description: The contents of register ‘f’ are
incremented. If ‘d’ is 0’, the result is
placed in W. If ‘d’ is1’, the result is
placed back in register ‘f’ (default).
If the result is not 0’, the next
instruction which is already fetched is
discarded and a NOP is executed
instead, making it a two-cycle
instruction.
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE INFSNZ REG, 1, 0
ZERO
NZERO
Before Instruction
PC = Address (HERE)
After Instruction
REG = REG + 1
If REG 0;
PC = Address (NZERO)
If REG = 0;
PC = Address (ZERO)
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IORLW Inclusive OR Literal with W
Syntax: IORLW k
Operands: 0 k 255
Operation: (W) .OR. k W
Status Affected: N, Z
Encoding: 0000 1001 kkkk kkkk
Description: The contents of W are ORed with the
eight-bit literal ‘k’. The result is placed
in W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
W
Example: IORLW 35h
Before Instruction
W=9Ah
After Instruction
W=BFh
IORWF Inclusive OR W with f
Syntax: IORWF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) .OR. (f) dest
Status Affected: N, Z
Encoding: 0001 00da ffff ffff
Description: Inclusive OR W with register ‘f’. If ‘d’ is
0’, the result is placed in W. If ‘d’ is ‘1’,
the result is placed back in register ‘f’
(default).
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: IORWF RESULT, 0, 1
Before Instruction
RESULT = 13h
W = 91h
After Instruction
RESULT = 13h
W = 93h
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 353
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LFSR Load FSR
Syntax: LFSR f, k
Operands: 0 f 2
0 k 4095
Operation: k FSRf
Status Affected: None
Encoding: 1110
1111
1110
0000
00ff
k7kkk
k11kkk
kkkk
Description: The 12-bit literal ‘k’ is loaded into the
file select register pointed to by ‘f’.
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘k’ MSB
Process
Data
Write
literal ‘k’
MSB to
FSRfH
Decode Read literal
‘k’ LSB
Process
Data
Write literal
‘k’ to FSRfL
Example: LFSR 2, 3ABh
After Instruction
FSR2H = 03h
FSR2L = ABh
MOVF Move f
Syntax: MOVF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: f dest
Status Affected: N, Z
Encoding: 0101 00da ffff ffff
Description: The contents of register ‘f’ are moved to
a destination dependent upon the
status of ‘d’. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is1’, the result is
placed back in register ‘f’ (default).
Location ‘f’ can be anywhere in the
256-byte bank.
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
W
Example: MOVF REG, 0, 0
Before Instruction
REG = 22h
W=FFh
After Instruction
REG = 22h
W = 22h
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MOVFF Move f to f
Syntax: MOVFF fs,fd
Operands: 0 fs 4095
0 fd 4095
Operation: (fs) fd
Status Affected: None
Encoding:
1st word (source)
2nd word (destin.)
1100
1111
ffff
ffff
ffff
ffff
ffffs
ffffd
Description: The contents of source register ‘fs’ are
moved to destination register ‘fd’.
Location of source ‘fs’ can be anywhere
in the 4096-byte data space (000h to
FFFh) and location of destination ‘fd
can also be anywhere from 000h to
FFFh.
Either source or destination can be W
(a useful special situation).
MOVFF is particularly useful for
transferring a data memory location to a
peripheral register (such as the transmit
buffer or an I/O port).
The MOVFF instruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
(src)
Process
Data
No
operation
Decode No
operation
No dummy
read
No
operation
Write
register ‘f’
(dest)
Example: MOVFF REG1, REG2
Before Instruction
REG1 = 33h
REG2 = 11h
After Instruction
REG1 = 33h
REG2 = 33h
MOVLB Move Literal to Low Nibble in BSR
Syntax: MOVLW k
Operands: 0 k 255
Operation: k BSR
Status Affected: None
Encoding: 0000 0001 kkkk kkkk
Description: The eight-bit literal ‘k’ is loaded into the
Bank Select Register (BSR). The value
of BSR<7:4> always remains ‘0
regardless of the value of k7:k4.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write literal
‘k’ to BSR
Example: MOVLB 5
Before Instruction
BSR Register = 02h
After Instruction
BSR Register = 05h
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 355
PIC18F87J11 FAMILY
MOVLW Move Literal to W
Syntax: MOVLW k
Operands: 0 k 255
Operation: k W
Status Affected: None
Encoding: 0000 1110 kkkk kkkk
Description: The eight-bit literal ‘k’ is loaded into W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
W
Example: MOVLW 5Ah
After Instruction
W=5Ah
MOVWF Move W to f
Syntax: MOVWF f {,a}
Operands: 0 f 255
a [0,1]
Operation: (W) f
Status Affected: None
Encoding: 0110 111a ffff ffff
Description: Move data from W to register ‘f’.
Location ‘f’ can be anywhere in the
256-byte bank.
If ‘a’ is0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: MOVWF REG, 0
Before Instruction
W=4Fh
REG = FFh
After Instruction
W=4Fh
REG = 4Fh
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MULLW Multiply Literal with W
Syntax: MULLW k
Operands: 0 k 255
Operation: (W) x k PRODH:PRODL
Status Affected: None
Encoding: 0000 1101 kkkk kkkk
Description: An unsigned multiplication is carried
out between the contents of W and the
8-bit literal ‘k’. The 16-bit result is
placed in PRODH:PRODL register pair.
PRODH contains the high byte.
W is unchanged.
None of the Status flags are affected.
Note that neither Overflow nor Carry is
possible in this operation. A Zero result
is possible but not detected.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write
registers
PRODH:
PRODL
Example: MULLW 0C4h
Before Instruction
W=E2h
PRODH = ?
PRODL = ?
After Instruction
W=E2h
PRODH = ADh
PRODL = 08h
MULWF Multiply W with f
Syntax: MULWF f {,a}
Operands: 0 f 255
a [0,1]
Operation: (W) x (f) PRODH:PRODL
Status Affected: None
Encoding: 0000 001a ffff ffff
Description: An unsigned multiplication is carried out
between the contents of W and the
register file location ‘f’. The 16-bit result is
stored in the PRODH:PRODL register
pair. PRODH contains the high byte. Both
W and ‘f’ are unchanged.
None of the Status flags are affected.
Note that neither Overflow nor Carry is
possible in this operation. A Zero result is
possible but not detected.
If ‘a’ is0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction set
is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f
Process
Data
Write
registers
PRODH:
PRODL
Example: MULWF REG, 1
Before Instruction
W=C4h
REG = B5h
PRODH = ?
PRODL = ?
After Instruction
W=C4h
REG = B5h
PRODH = 8Ah
PRODL = 94h
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NEGF Negate f
Syntax: NEGF f {,a}
Operands: 0 f 255
a [0,1]
Operation: (f) + 1 f
Status Affected: N, OV, C, DC, Z
Encoding: 0110 110a ffff ffff
Description: Location ‘f’ is negated using two’s
complement. The result is placed in the
data memory location ‘f’.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: NEGF REG, 1
Before Instruction
REG = 0011 1010 [3Ah]
After Instruction
REG = 1100 0110 [C6h]
NOP No Operation
Syntax: NOP
Operands: None
Operation: No operation
Status Affected: None
Encoding: 0000
1111
0000
xxxx
0000
xxxx
0000
xxxx
Description: No operation.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
No
operation
No
operation
Example:
None.
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POP Pop Top of Return Stack
Syntax: POP
Operands: None
Operation: (TOS) bit bucket
Status Affected: None
Encoding: 0000 0000 0000 0110
Description: The TOS value is pulled off the return
stack and is discarded. The TOS value
then becomes the previous value that
was pushed onto the return stack.
This instruction is provided to enable
the user to properly manage the return
stack to incorporate a software stack.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
POP TOS
value
No
operation
Example: POP
GOTO NEW
Before Instruction
TOS = 0031A2h
Stack (1 level down) = 014332h
After Instruction
TOS = 014332h
PC = NEW
PUSH Push Top of Return Stack
Syntax: PUSH
Operands: None
Operation: (PC + 2) TOS
Status Affected: None
Encoding: 0000 0000 0000 0101
Description: The PC + 2 is pushed onto the top of
the return stack. The previous TOS
value is pushed down on the stack.
This instruction allows implementing a
software stack by modifying TOS and
then pushing it onto the return stack.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode PUSH
PC + 2 onto
return stack
No
operation
No
operation
Example: PUSH
Before Instruction
TOS = 345Ah
PC = 0124h
After Instruction
PC = 0126h
TOS = 0126h
Stack (1 level down) = 345Ah
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RCALL Relative Call
Syntax: RCALL n
Operands: -1024 n 1023
Operation: (PC) + 2 TOS,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1101 1nnn nnnn nnnn
Description: Subroutine call with a jump up to 1K
from the current location. First, return
address (PC + 2) is pushed onto the
stack. Then, add the 2’s complement
number ‘2n’ to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is a
two-cycle instruction.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
PUSH PC
to stack
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
Example: HERE RCALL Jump
Before Instruction
PC = Address (HERE)
After Instruction
PC = Address (Jump)
TOS = Address (HERE + 2)
RESET Reset
Syntax: RESET
Operands: None
Operation: Reset all registers and flags that are
affected by a MCLR Reset.
Status Affected: All
Encoding: 0000 0000 1111 1111
Description: This instruction provides a way to
execute a MCLR Reset in software.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Start
reset
No
operation
No
operation
Example: RESET
After Instruction
Registers = Reset Value
Flags* = Reset Value
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RETFIE Return from Interrupt
Syntax: RETFIE {s}
Operands: s [0,1]
Operation: (TOS) PC,
1 GIE/GIEH or PEIE/GIEL;
if s = 1,
(WS) W,
(STATUSS) STATUS,
(BSRS) BSR,
PCLATU, PCLATH are unchanged
Status Affected: GIE/GIEH, PEIE/GIEL.
Encoding: 0000 0000 0001 000s
Description: Return from interrupt. Stack is popped
and Top-of-Stack (TOS) is loaded into
the PC. Interrupts are enabled by
setting either the high or low-priority
global interrupt enable bit. If ‘s’ = 1, the
contents of the shadow registers WS,
STATUSS and BSRS are loaded into
their corresponding registers W,
STATUS and BSR. If ‘s’ = 0, no update
of these registers occurs (default).
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
No
operation
POP PC
from stack
Set GIEH or
GIEL
No
operation
No
operation
No
operation
No
operation
Example: RETFIE 1
After Interrupt
PC = TOS
W=WS
BSR = BSRS
STATUS = STATUSS
GIE/GIEH, PEIE/GIEL = 1
RETLW Return Literal to W
Syntax: RETLW k
Operands: 0 k 255
Operation: k W,
(TOS) PC,
PCLATU, PCLATH are unchanged
Status Affected: None
Encoding: 0000 1100 kkkk kkkk
Description: W is loaded with the eight-bit literal ‘k’.
The program counter is loaded from the
top of the stack (the return address).
The high address latch (PCLATH)
remains unchanged.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
POP PC
from stack,
write to W
No
operation
No
operation
No
operation
No
operation
Example:
CALL TABLE ; W contains table
; offset value
; W now has
; table value
:
TABLE
ADDWF PCL ; W = offset
RETLW k0 ; Begin table
RETLW k1 ;
:
:
RETLW kn ; End of table
Before Instruction
W = 07h
After Instruction
W = value of kn
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RETURN Return from Subroutine
Syntax: RETURN {s}
Operands: s [0,1]
Operation: (TOS) PC;
if s = 1,
(WS) W,
(STATUSS) STATUS,
(BSRS) BSR,
PCLATU, PCLATH are unchanged
Status Affected: None
Encoding: 0000 0000 0001 001s
Description: Return from subroutine. The stack is
popped and the top of the stack (TOS)
is loaded into the program counter. If
‘s’= 1, the contents of the shadow
registers WS, STATUSS and BSRS are
loaded into their corresponding
registers W, STATUS and BSR. If
‘s’ = 0, no update of these registers
occurs (default).
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
Process
Data
POP PC
from stack
No
operation
No
operation
No
operation
No
operation
Example: RETURN
After Instruction:
PC = TOS
RLCF Rotate Left f through Carry
Syntax: RLCF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f<n>) dest<n + 1>,
(f<7>) C,
(C) dest<0>
Status Affected: C, N, Z
Encoding: 0011 01da ffff ffff
Description: The contents of register ‘f’ are rotated
one bit to the left through the Carry flag.
If ‘d’ is0’, the result is placed in W. If ‘d’
is ‘1’, the result is stored back in register
‘f’ (default).
If ‘a’ is0’, the Access Bank is selected.
If ‘a’ is1’, the BSR is used to select the
GPR bank.
If ‘a’ is0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: RLCF REG, 0, 0
Before Instruction
REG = 1110 0110
C=0
After Instruction
REG = 1110 0110
W=1100 1100
C=1
Cregister f
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RLNCF Rotate Left f (No Carry)
Syntax: RLNCF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f<n>) dest<n + 1>,
(f<7>) dest<0>
Status Affected: N, Z
Encoding: 0100 01da ffff ffff
Description: The contents of register ‘f’ are rotated
one bit to the left. If ‘d’ is ‘0’, the result
is placed in W. If ‘d’ is 1’, the result is
stored back in register ‘f’ (default).
If ‘a’ is0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: RLNCF REG, 1, 0
Before Instruction
REG = 1010 1011
After Instruction
REG = 0101 0111
register f
RRCF Rotate Right f through Carry
Syntax: RRCF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f<n>) dest<n – 1>,
(f<0>) C,
(C) dest<7>
Status Affected: C, N, Z
Encoding: 0011 00da ffff ffff
Description: The contents of register ‘f’ are rotated
one bit to the right through the Carry
flag. If ‘d’ is ‘0’, the result is placed in W.
If ‘d’ is ‘1’, the result is placed back in
register ‘f’ (default).
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: RRCF REG, 0, 0
Before Instruction
REG = 1110 0110
C=0
After Instruction
REG = 1110 0110
W=0111 0011
C=0
Cregister f
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RRNCF Rotate Right f (No Carry)
Syntax: RRNCF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f<n>) dest<n – 1>,
(f<0>) dest<7>
Status Affected: N, Z
Encoding: 0100 00da ffff ffff
Description: The contents of register ‘f’ are rotated
one bit to the right. If ‘d’ is ‘0’, the result
is placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank will be
selected, overriding the BSR value. If ‘a’
is ‘1’, then the bank will be selected as
per the BSR value (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example 1: RRNCF REG, 1, 0
Before Instruction
REG = 1101 0111
After Instruction
REG = 1110 1011
Example 2: RRNCF REG, 0, 0
Before Instruction
W=?
REG = 1101 0111
After Instruction
W=1110 1011
REG = 1101 0111
register f
SETF Set f
Syntax: SETF f {,a}
Operands: 0 f 255
a [0,1]
Operation: FFh f
Status Affected: None
Encoding: 0110 100a ffff ffff
Description: The contents of the specified register
are set to FFh.
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: SETF REG,1
Before Instruction
REG = 5Ah
After Instruction
REG = FFh
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SLEEP Enter Sleep Mode
Syntax: SLEEP
Operands: None
Operation: 00h WDT,
0 WDT postscaler,
1 TO,
0 PD
Status Affected: TO, PD
Encoding: 0000 0000 0000 0011
Description: The Power-Down status bit (PD) is
cleared. The Time-out status bit (TO)
is set. The Watchdog Timer and its
postscaler are cleared.
The processor is put into Sleep mode
with the oscillator stopped.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
Process
Data
Go to
Sleep
Example: SLEEP
Before Instruction
TO =?
PD =?
After Instruction
TO =1
PD =0
† If WDT causes wake-up, this bit is cleared.
SUBFWB Subtract f from W with Borrow
Syntax: SUBFWB f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) – (f) – (C) dest
Status Affected: N, OV, C, DC, Z
Encoding: 0101 01da ffff ffff
Description: Subtract register ‘f’ and Carry flag
(borrow) from W (2’s complement
method). If ‘d’ is ‘0’, the result is stored in
W. If ‘d’ is ‘1’, the result is stored in
register ‘f’ (default).
If ‘a’ is0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example 1: SUBFWB REG, 1, 0
Before Instruction
REG = 3
W=2
C=1
After Instruction
REG = FF
W=2
C=0
Z=0
N = 1 ; result is negative
Example 2: SUBFWB REG, 0, 0
Before Instruction
REG = 2
W=5
C=1
After Instruction
REG = 2
W=3
C=1
Z=0
N = 0 ; result is positive
Example 3: SUBFWB REG, 1, 0
Before Instruction
REG = 1
W=2
C=0
After Instruction
REG = 0
W=2
C=1
Z = 1 ; result is zero
N=0
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 365
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SUBLW Subtract W from Literal
Syntax: SUBLW k
Operands: 0 k 255
Operation: k – (W) W
Status Affected: N, OV, C, DC, Z
Encoding: 0000 1000 kkkk kkkk
Description: W is subtracted from the eight-bit
literal ‘k’. The result is placed in W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
W
Example 1: SUBLW 02h
Before Instruction
W = 01h
C=?
After Instruction
W = 01h
C = 1 ; result is positive
Z=0
N=0
Example 2: SUBLW 02h
Before Instruction
W = 02h
C=?
After Instruction
W = 00h
C = 1 ; result is zero
Z=1
N=0
Example 3: SUBLW 02h
Before Instruction
W = 03h
C=?
After Instruction
W = FFh ; (2’s complement)
C = 0 ; result is negative
Z=0
N=1
SUBWF Subtract W from f
Syntax: SUBWF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) – (W) dest
Status Affected: N, OV, C, DC, Z
Encoding: 0101 11da ffff ffff
Description: Subtract W from register ‘f’ (2’s
complement method). If ‘d’ is0’, the
result is stored in W. If ‘d’ is ‘1’, the result
is stored back in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example 1: SUBWF REG, 1, 0
Before Instruction
REG = 3
W=2
C=?
After Instruction
REG = 1
W=2
C = 1 ; result is positive
Z=0
N=0
Example 2: SUBWF REG, 0, 0
Before Instruction
REG = 2
W=2
C=?
After Instruction
REG = 2
W=0
C = 1 ; result is zero
Z=1
N=0
Example 3: SUBWF REG, 1, 0
Before Instruction
REG = 1
W=2
C=?
After Instruction
REG = FFh ;(2’s complement)
W=2
C = 0 ; result is negative
Z=0
N=1
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SUBWFB Subtract W from f with Borrow
Syntax: SUBWFB f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) – (W) – (C) dest
Status Affected: N, OV, C, DC, Z
Encoding: 0101 10da ffff ffff
Description: Subtract W and the Carry flag (borrow)
from register ‘f’ (2’s complement
method). If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is ‘1’, the result is stored back
in register ‘f’ (default).
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example 1: SUBWFB REG, 1, 0
Before Instruction
REG = 19h (0001 1001)
W=0Dh(0000 1101)
C=1
After Instruction
REG = 0Ch (0000 1011)
W=0Dh(0000 1101)
C=1
Z=0
N = 0 ; result is positive
Example 2: SUBWFB REG, 0, 0
Before Instruction
REG = 1Bh (0001 1011)
W=1Ah(0001 1010)
C=0
After Instruction
REG = 1Bh (0001 1011)
W = 00h
C=1
Z = 1 ; result is zero
N=0
Example 3: SUBWFB REG, 1, 0
Before Instruction
REG = 03h (0000 0011)
W=0Eh(0000 1101)
C=1
After Instruction
REG = F5h (1111 0100)
; [2’s comp]
W=0Eh(0000 1101)
C=0
Z=0
N = 1 ; result is negative
SWAPF Swap f
Syntax: SWAPF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f<3:0>) dest<7:4>,
(f<7:4>) dest<3:0>
Status Affected: None
Encoding: 0011 10da ffff ffff
Description: The upper and lower nibbles of register
‘f’ are exchanged. If ‘d’ is ‘0’, the result
is placed in W. If ‘d’ is ‘1’, the result is
placed in register ‘f’ (default).
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: SWAPF REG, 1, 0
Before Instruction
REG = 53h
After Instruction
REG = 35h
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 367
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TBLRD Table Read
Syntax: TBLRD ( *; *+; *-; +*)
Operands: None
Operation: if TBLRD *,
(Prog Mem (TBLPTR)) TABLAT,
TBLPTR – No Change;
if TBLRD *+,
(Prog Mem (TBLPTR)) TABLAT,
(TBLPTR) + 1 TBLPTR;
if TBLRD *-,
(Prog Mem (TBLPTR)) TABLAT,
(TBLPTR) – 1 TBLPTR;
if TBLRD +*,
(TBLPTR) + 1 TBLPTR,
(Prog Mem (TBLPTR)) TABLAT
Status Affected: None
Encoding: 0000 0000 0000 10nn
nn=0 *
=1 *+
=2 *-
=3 +*
Description: This instruction is used to read the contents
of Program Memory (P.M.). To address the
program memory, a pointer called Table
Pointer (TBLPTR) is used.
The TBLPTR (a 21-bit pointer) points to
each byte in the program memory. TBLPTR
has a 2-Mbyte address range.
TBLPTR<0> = 0:Least Significant Byte of
Program Memory Word
TBLPTR<0> = 1:Most Significant Byte of
Program Memory Word
The TBLRD instruction can modify the value
of TBLPTR as follows:
no change
post-increment
post-decrement
pre-increment
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
No
operation
No
operation
No
operation
No operation
(Read Program
Memory)
No
operation
No operation
(Write
TABLAT)
TBLRD Table Read (Continued)
Example 1: TBLRD *+ ;
Before Instruction
TABLAT = 55h
TBLPTR = 00A356h
MEMORY(00A356h) = 34h
After Instruction
TABLAT = 34h
TBLPTR = 00A357h
Example 2: TBLRD +* ;
Before Instruction
TABLAT = AAh
TBLPTR = 01A357h
MEMORY(01A357h) = 12h
MEMORY(01A358h) = 34h
After Instruction
TABLAT = 34h
TBLPTR = 01A358h
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TBLWT Table Write
Syntax: TBLWT ( *; *+; *-; +*)
Operands: None
Operation: if TBLWT*,
(TABLAT) Holding Register,
TBLPTR – No Change;
if TBLWT*+,
(TABLAT) Holding Register,
(TBLPTR) + 1 TBLPTR;
if TBLWT*-,
(TABLAT) Holding Register,
(TBLPTR) – 1 TBLPTR;
if TBLWT+*,
(TBLPTR) + 1 TBLPTR,
(TABLAT) Holding Register
Status Affected: None
Encoding: 0000 0000 0000 11nn
nn=0 *
=1 *+
=2 *-
=3 +*
Description: This instruction uses the 3 LSBs of
TBLPTR to determine which of the
8 holding registers the TABLAT is written
to. The holding registers are used to
program the contents of Program Memory
(P.M.). (Refer to Section 5.0 “Memory
Organization” for additional details on
programming Flash memory.)
The TBLPTR (a 21-bit pointer) points to
each byte in the program memory.
TBLPTR has a 2-Mbyte address range.
The LSb of the TBLPTR selects which
byte of the program memory location to
access.
TBLPTR<0> = 0:Least Significant Byte
of Program Memory
Word
TBLPTR<0> = 1:Most Significant Byte
of Program Memory
Word
The TBLWT instruction can modify the
value of TBLPTR as follows:
no change
post-increment
post-decrement
pre-increment
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
No
operation
No
operation
No
operation
No
operation
(Read
TABLAT)
No
operation
No
operation
(Write to
Holding
Register)
TBLWT Table Write (Continued)
Example 1: TBLWT *+;
Before Instruction
TABLAT = 55h
TBLPTR = 00A356h
HOLDING REGISTER
(00A356h) = FFh
After Instructions (table write completion)
TABLAT = 55h
TBLPTR = 00A357h
HOLDING REGISTER
(00A356h) = 55h
Example 2: TBLWT +*;
Before Instruction
TABLAT = 34h
TBLPTR = 01389Ah
HOLDING REGISTER
(01389Ah) = FFh
HOLDING REGISTER
(01389Bh) = FFh
After Instruction (table write completion)
TABLAT = 34h
TBLPTR = 01389Bh
HOLDING REGISTER
(01389Ah) = FFh
HOLDING REGISTER
(01389Bh) = 34h
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 369
PIC18F87J11 FAMILY
TSTFSZ Test f, Skip if 0
Syntax: TSTFSZ f {,a}
Operands: 0 f 255
a [0,1]
Operation: skip if f = 0
Status Affected: None
Encoding: 0110 011a ffff ffff
Description: If ‘f’ = 0, the next instruction fetched
during the current instruction execution
is discarded and a NOP is executed,
making this a two-cycle instruction.
If ‘a’ is0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE TSTFSZ CNT, 1
NZERO :
ZERO :
Before Instruction
PC = Address (HERE)
After Instruction
If CNT = 00h,
PC = Address (ZERO)
If CNT 00h,
PC = Address (NZERO)
XORLW Exclusive OR Literal with W
Syntax: XORLW k
Operands: 0 k 255
Operation: (W) .XOR. k W
Status Affected: N, Z
Encoding: 0000 1010 kkkk kkkk
Description: The contents of W are XORed with
the 8-bit literal ‘k’. The result is placed
in W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
W
Example: XORLW 0AFh
Before Instruction
W=B5h
After Instruction
W=1Ah
PIC18F87J11 FAMILY
DS39778C-page 370 Preliminary © 2008 Microchip Technology Inc.
XORWF Exclusive OR W with f
Syntax: XORWF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) .XOR. (f) dest
Status Affected: N, Z
Encoding: 0001 10da ffff ffff
Description: Exclusive OR the contents of W with
register ‘f’. If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is1’, the result is stored back
in the register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: XORWF REG, 1, 0
Before Instruction
REG = AFh
W=B5h
After Instruction
REG = 1Ah
W=B5h
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 371
PIC18F87J11 FAMILY
25.2 Extended Instruction Set
In addition to the standard 75 instructions of the PIC18
instruction set, the PIC18F87J11 Family family of
devices also provide an optional extension to the core
CPU functionality. The added features include eight
additional instructions that augment Indirect and
Indexed Addressing operations and the implementa-
tion of Indexed Literal Offset Addressing for many of
the standard PIC18 instructions.
The additional features of the extended instruction set
are enabled by default on unprogrammed devices.
Users must properly set or clear the XINST Configura-
tion bit during programming to enable or disable these
features.
The instructions in the extended set can all be
classified as literal operations, which either manipulate
the File Select Registers, or use them for Indexed
Addressing. Two of the instructions, ADDFSR and
SUBFSR, each have an additional special instantiation
for using FSR2. These versions (ADDULNK and
SUBULNK) allow for automatic return after execution.
The extended instructions are specifically implemented
to optimize re-entrant program code (that is, code that
is recursive or that uses a software stack) written in
high-level languages, particularly C. Among other
things, they allow users working in high-level
languages to perform certain operations on data
structures more efficiently. These include:
dynamic allocation and deallocation of software
stack space when entering and leaving
subroutines
function pointer invocation
software Stack Pointer manipulation
manipulation of variables located in a software
stack
A summary of the instructions in the extended instruc-
tion set is provided in Table 25-3. Detailed descriptions
are provided in Section 25.2.2 “Extended Instruction
Set”. The opcode field descriptions in Table 25-1 (page
330) apply to both the standard and extended PIC18
instruction sets.
25.2.1 EXTENDED INSTRUCTION SYNTAX
Most of the extended instructions use indexed argu-
ments, using one of the File Select Registers and some
offset to specify a source or destination register. When
an argument for an instruction serves as part of
Indexed Addressing, it is enclosed in square brackets
(“[ ]”). This is done to indicate that the argument is used
as an index or offset. The MPASM™ Assembler will
flag an error if it determines that an index or offset value
is not bracketed.
When the extended instruction set is enabled, brackets
are also used to indicate index arguments in
byte-oriented and bit-oriented instructions. This is in
addition to other changes in their syntax. For more
details, see Section 25.2.3.1 “Extended Instruction
Syntax with Standard PIC18 Commands”.
TABLE 25-3: EXTENSIONS TO THE PIC18 INSTRUCTION SET
Note: The instruction set extension and the
Indexed Literal Offset Addressing mode
were designed for optimizing applications
written in C; the user may likely never use
these instructions directly in assembler.
The syntax for these commands is
provided as a reference for users who may
be reviewing code that has been
generated by a compiler.
Note: In the past, square brackets have been
used to denote optional arguments in the
PIC18 and earlier instruction sets. In this
text and going forward, optional
arguments are denoted by braces (“{ }”).
Mnemonic,
Operands Description Cycles
16-Bit Instruction Word Status
Affected
MSb LSb
ADDFSR
ADDULNK
CALLW
MOVSF
MOVSS
PUSHL
SUBFSR
SUBULNK
f, k
k
zs, fd
zs, zd
k
f, k
k
Add Literal to FSR
Add Literal to FSR2 and Return
Call Subroutine using WREG
Move zs (source) to 1st word
fd (destination) 2nd word
Move zs (source) to 1st word
zd (destination) 2nd word
Store Literal at FSR2,
Decrement FSR2
Subtract Literal from FSR
Subtract Literal from FSR2 and
Return
1
2
2
2
2
1
1
2
1110
1110
0000
1110
1111
1110
1111
1110
1110
1110
1000
1000
0000
1011
ffff
1011
xxxx
1010
1001
1001
ffkk
11kk
0001
0zzz
ffff
1zzz
xzzz
kkkk
ffkk
11kk
kkkk
kkkk
0100
zzzz
ffff
zzzz
zzzz
kkkk
kkkk
kkkk
None
None
None
None
None
None
None
None
PIC18F87J11 FAMILY
DS39778C-page 372 Preliminary © 2008 Microchip Technology Inc.
25.2.2 EXTENDED INSTRUCTION SET
ADDFSR Add Literal to FSR
Syntax: ADDFSR f, k
Operands: 0 k 63
f [ 0, 1, 2 ]
Operation: FSR(f) + k FSR(f)
Status Affected: None
Encoding: 1110 1000 ffkk kkkk
Description: The 6-bit literal ‘k’ is added to the
contents of the FSR specified by ‘f’.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
FSR
Example: ADDFSR 2, 23h
Before Instruction
FSR2 = 03FFh
After Instruction
FSR2 = 0422h
ADDULNK Add Literal to FSR2 and Return
Syntax: ADDULNK k
Operands: 0 k 63
Operation: FSR2 + k FSR2,
(TOS) PC
Status Affected: None
Encoding: 1110 1000 11kk kkkk
Description: The 6-bit literal ‘k’ is added to the
contents of FSR2. A RETURN is then
executed by loading the PC with the
TOS.
The instruction takes two cycles to
execute; a NOP is performed during
the second cycle.
This may be thought of as a special
case of the ADDFSR instruction,
where f = 3 (binary ‘11’); it operates
only on FSR2.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
FSR
No
Operation
No
Operation
No
Operation
No
Operation
Example: ADDULNK 23h
Before Instruction
FSR2 = 03FFh
PC = 0100h
After Instruction
FSR2 = 0422h
PC = (TOS)
Note: All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in
symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 373
PIC18F87J11 FAMILY
CALLW Subroutine Call using WREG
Syntax: CALLW
Operands: None
Operation: (PC + 2) TOS,
(W) PCL,
(PCLATH) PCH,
(PCLATU) PCU
Status Affected: None
Encoding: 0000 0000 0001 0100
Description First, the return address (PC + 2) is
pushed onto the return stack. Next, the
contents of W are written to PCL; the
existing value is discarded. Then, the
contents of PCLATH and PCLATU are
latched into PCH and PCU,
respectively. The second cycle is
executed as a NOP instruction while the
new next instruction is fetched.
Unlike CALL, there is no option to
update W, STATUS or BSR.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
WREG
Push PC to
stack
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE CALLW
Before Instruction
PC = address (HERE)
PCLATH = 10h
PCLATU = 00h
W = 06h
After Instruction
PC = 001006h
TOS = address (HERE + 2)
PCLATH = 10h
PCLATU = 00h
W = 06h
MOVSF Move Indexed to f
Syntax: MOVSF [zs], fd
Operands: 0 zs 127
0 fd 4095
Operation: ((FSR2) + zs) fd
Status Affected: None
Encoding:
1st word (source)
2nd word (destin.)
1110
1111
1011
ffff
0zzz
ffff
zzzzs
ffffd
Description: The contents of the source register are
moved to destination register ‘fd’. The
actual address of the source register is
determined by adding the 7-bit literal
offset ‘zs’, in the first word, to the value
of FSR2. The address of the destination
register is specified by the 12-bit literal
‘fd’ in the second word. Both addresses
can be anywhere in the 4096-byte data
space (000h to FFFh).
The MOVSF instruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register.
If the resultant source address points to
an Indirect Addressing register, the
value returned will be 00h.
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Determine
source addr
Determine
source addr
Read
source reg
Decode No
operation
No dummy
read
No
operation
Write
register ‘f’
(dest)
Example: MOVSF [05h], REG2
Before Instruction
FSR2 = 80h
Contents
of 85h = 33h
REG2 = 11h
After Instruction
FSR2 = 80h
Contents
of 85h = 33h
REG2 = 33h
PIC18F87J11 FAMILY
DS39778C-page 374 Preliminary © 2008 Microchip Technology Inc.
MOVSS Move Indexed to Indexed
Syntax: MOVSS [zs], [zd]
Operands: 0 zs 127
0 zd 127
Operation: ((FSR2) + zs) ((FSR2) + zd)
Status Affected: None
Encoding:
1st word (source)
2nd word (dest.)
1110
1111
1011
xxxx
1zzz
xzzz
zzzzs
zzzzd
Description The contents of the source register are
moved to the destination register. The
addresses of the source and destination
registers are determined by adding the
7-bit literal offsets ‘zs’ or ‘zd’,
respectively, to the value of FSR2. Both
registers can be located anywhere in
the 4096-byte data memory space
(000h to FFFh).
The MOVSS instruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register.
If the resultant source address points to
an Indirect Addressing register, the
value returned will be 00h. If the
resultant destination address points to
an Indirect Addressing register, the
instruction will execute as a NOP.
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Determine
source addr
Determine
source addr
Read
source reg
Decode Determine
dest addr
Determine
dest addr
Write
to dest reg
Example: MOVSS [05h], [06h]
Before Instruction
FSR2 = 80h
Contents
of 85h = 33h
Contents
of 86h = 11h
After Instruction
FSR2 = 80h
Contents
of 85h = 33h
Contents
of 86h = 33h
PUSHL Store Literal at FSR2, Decrement FSR2
Syntax: PUSHL k
Operands: 0k 255
Operation: k (FSR2),
FSR2 – 1 FSR2
Status Affected: None
Encoding: 1111 1010 kkkk kkkk
Description: The 8-bit literal ‘k’ is written to the data
memory address specified by FSR2.
FSR2 is decremented by 1 after the
operation.
This instruction allows users to push
values onto a software stack.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read ‘k’ Process
data
Write to
destination
Example: PUSHL 08h
Before Instruction
FSR2H:FSR2L = 01ECh
Memory (01ECh) = 00h
After Instruction
FSR2H:FSR2L = 01EBh
Memory (01ECh) = 08h
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 375
PIC18F87J11 FAMILY
SUBFSR Subtract Literal from FSR
Syntax: SUBFSR f, k
Operands: 0 k 63
f [ 0, 1, 2 ]
Operation: FSRf – k FSRf
Status Affected: None
Encoding: 1110 1001 ffkk kkkk
Description: The 6-bit literal ‘k’ is subtracted from
the contents of the FSR specified
by ‘f’.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: SUBFSR 2, 23h
Before Instruction
FSR2 = 03FFh
After Instruction
FSR2 = 03DCh
SUBULNK Subtract Literal from FSR2 and Return
Syntax: SUBULNK k
Operands: 0 k 63
Operation: FSR2 – k FSR2,
(TOS) PC
Status Affected: None
Encoding: 1110 1001 11kk kkkk
Description: The 6-bit literal ‘k’ is subtracted from the
contents of the FSR2. A RETURN is then
executed by loading the PC with the
TOS.
The instruction takes two cycles to
execute; a NOP is performed during the
second cycle.
This may be thought of as a special case
of the SUBFSR instruction, where f = 3
(binary ‘11’); it operates only on FSR2.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
No
Operation
No
Operation
No
Operation
No
Operation
Example: SUBULNK 23h
Before Instruction
FSR2 = 03FFh
PC = 0100h
After Instruction
FSR2 = 03DCh
PC = (TOS)
PIC18F87J11 FAMILY
DS39778C-page 376 Preliminary © 2008 Microchip Technology Inc.
25.2.3 BYTE-ORIENTED AND
BIT-ORIENTED INSTRUCTIONS IN
INDEXED LITERAL OFFSET MODE
In addition to eight new commands in the extended set,
enabling the extended instruction set also enables
Indexed Literal Offset Addressing (Section 5.6.1
“Indexed Addressing with Literal Offset”). This has
a significant impact on the way that many commands of
the standard PIC18 instruction set are interpreted.
When the extended set is disabled, addresses embed-
ded in opcodes are treated as literal memory locations:
either as a location in the Access Bank (a = 0) or in a
GPR bank designated by the BSR (a = 1). When the
extended instruction set is enabled and a = 0, however,
a file register argument of 5Fh or less is interpreted as
an offset from the pointer value in FSR2 and not as a
literal address. For practical purposes, this means that
all instructions that use the Access RAM bit as an
argument – that is, all byte-oriented and bit-oriented
instructions, or almost half of the core PIC18 instruc-
tions – may behave differently when the extended
instruction set is enabled.
When the content of FSR2 is 00h, the boundaries of the
Access RAM are essentially remapped to their original
values. This may be useful in creating
backward-compatible code. If this technique is used, it
may be necessary to save the value of FSR2 and
restore it when moving back and forth between C and
assembly routines in order to preserve the Stack
Pointer. Users must also keep in mind the syntax
requirements of the extended instruction set (see
Section 25.2.3.1 “Extended Instruction Syntax with
Standard PIC18 Commands”).
Although the Indexed Literal Offset mode can be very
useful for dynamic stack and pointer manipulation, it
can also be very annoying if a simple arithmetic opera-
tion is carried out on the wrong register. Users who are
accustomed to the PIC18 programming must keep in
mind that, when the extended instruction set is
enabled, register addresses of 5Fh or less are used for
Indexed Literal Offset Addressing.
Representative examples of typical byte-oriented and
bit-oriented instructions in the Indexed Literal Offset
mode are provided on the following page to show how
execution is affected. The operand conditions shown in
the examples are applicable to all instructions of these
types.
25.2.3.1 Extended Instruction Syntax with
Standard PIC18 Commands
When the extended instruction set is enabled, the file
register argument ‘f’ in the standard byte-oriented and
bit-oriented commands is replaced with the literal offset
value ‘k’. As already noted, this occurs only when ‘f’ is
less than or equal to 5Fh. When an offset value is used,
it must be indicated by square brackets (“[ ]”). As with
the extended instructions, the use of brackets indicates
to the compiler that the value is to be interpreted as an
index or an offset. Omitting the brackets, or using a
value greater than 5Fh within the brackets, will
generate an error in the MPASM Assembler.
If the index argument is properly bracketed for Indexed
Literal Offset Addressing, the Access RAM argument is
never specified; it will automatically be assumed to be
0’. This is in contrast to standard operation (extended
instruction set disabled), when ‘a’ is set on the basis of
the target address. Declaring the Access RAM bit in
this mode will also generate an error in the MPASM
Assembler.
The destination argument ‘d’ functions as before.
In the latest versions of the MPASM Assembler,
language support for the extended instruction set must
be explicitly invoked. This is done with either the
command line option, /y, or the PE directive in the
source listing.
25.2.4 CONSIDERATIONS WHEN
ENABLING THE EXTENDED
INSTRUCTION SET
It is important to note that the extensions to the instruc-
tion set may not be beneficial to all users. In particular,
users who are not writing code that uses a software
stack may not benefit from using the extensions to the
instruction set.
Additionally, the Indexed Literal Offset Addressing
mode may create issues with legacy applications
written to the PIC18 assembler. This is because
instructions in the legacy code may attempt to address
registers in the Access Bank below 5Fh. Since these
addresses are interpreted as literal offsets to FSR2
when the instruction set extension is enabled, the
application may read or write to the wrong data
addresses.
When porting an application to the PIC18F87J11 Fam-
ily family, it is very important to consider the type of
code. A large, re-entrant application that is written in C
and would benefit from efficient compilation will do well
when using the instruction set extensions. Legacy
applications that heavily use the Access Bank will most
likely not benefit from using the extended instruction
set.
Note: Enabling the PIC18 instruction set exten-
sion may cause legacy applications to
behave erratically or fail entirely.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 377
PIC18F87J11 FAMILY
ADDWF ADD W to Indexed
(Indexed Literal Offset mode)
Syntax: ADDWF [k] {,d}
Operands: 0 k 95
d [0,1]
Operation: (W) + ((FSR2) + k) dest
Status Affected: N, OV, C, DC, Z
Encoding: 0010 01d0 kkkk kkkk
Description: The contents of W are added to the
contents of the register indicated by
FSR2, offset by the value ‘k’.
If ‘d’ is ‘0’, the result is stored in W. If ‘d’
is ‘1’, the result is stored back in
register ‘f’ (default).
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read ‘k’ Process
Data
Write to
destination
Example: ADDWF [OFST] ,0
Before Instruction
W = 17h
OFST = 2Ch
FSR2 = 0A00h
Contents
of 0A2Ch = 20h
After Instruction
W = 37h
Contents
of 0A2Ch = 20h
BSF Bit Set Indexed
(Indexed Literal Offset mode)
Syntax: BSF [k], b
Operands: 0 f 95
0 b 7
Operation: 1 ((FSR2) + k)<b>
Status Affected: None
Encoding: 1000 bbb0 kkkk kkkk
Description: Bit ‘b’ of the register indicated by FSR2,
offset by the value ‘k’, is set.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: BSF [FLAG_OFST], 7
Before Instruction
FLAG_OFST = 0Ah
FSR2 = 0A00h
Contents
of 0A0Ah = 55h
After Instruction
Contents
of 0A0Ah = D5h
SETF Set Indexed
(Indexed Literal Offset mode)
Syntax: SETF [k]
Operands: 0 k 95
Operation: FFh ((FSR2) + k)
Status Affected: None
Encoding: 0110 1000 kkkk kkkk
Description: The contents of the register indicated by
FSR2, offset by ‘k’, are set to FFh.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read ‘k’ Process
Data
Write
register
Example: SETF [OFST]
Before Instruction
OFST = 2Ch
FSR2 = 0A00h
Contents
of 0A2Ch = 00h
After Instruction
Contents
of 0A2Ch = FFh
PIC18F87J11 FAMILY
DS39778C-page 378 Preliminary © 2008 Microchip Technology Inc.
25.2.5 SPECIAL CONSIDERATIONS WITH
MICROCHIP MPLAB® IDE TOOLS
The latest versions of Microchip’s software tools have
been designed to fully support the extended instruction
set for the PIC18F87J11 Family family. This includes
the MPLAB C18 C Compiler, MPASM assembly lan-
guage and MPLAB Integrated Development
Environment (IDE).
When selecting a target device for software
development, MPLAB IDE will automatically set default
Configuration bits for that device. The default setting for
the XINST Configuration bit is 0’, disabling the
extended instruction set and Indexed Literal Offset
Addressing. For proper execution of applications
developed to take advantage of the extended
instruction set, XINST must be set during
programming.
To develop software for the extended instruction set,
the user must enable support for the instructions and
the Indexed Addressing mode in their language tool(s).
Depending on the environment being used, this may be
done in several ways:
A menu option or dialog box within the
environment that allows the user to configure the
language tool and its settings for the project
A command line option
A directive in the source code
These options vary between different compilers,
assemblers and development environments. Users are
encouraged to review the documentation accompany-
ing their development systems for the appropriate
information.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 379
PIC18F87J11 FAMILY
26.0 DEVELOPMENT SUPPORT
The PIC® microcontrollers are supported with a full
range of hardware and software development tools:
Integrated Development Environment
- MPLAB® IDE Software
Assemblers/Compilers/Linkers
- MPASMTM Assembler
- MPLAB C18 and MPLAB C30 C Compilers
-MPLINK
TM Object Linker/
MPLIBTM Object Librarian
- MPLAB ASM30 Assembler/Linker/Library
Simulators
- MPLAB SIM Software Simulator
•Emulators
- MPLAB ICE 2000 In-Circuit Emulator
- MPLAB REAL ICE™ In-Circuit Emulator
In-Circuit Debugger
- MPLAB ICD 2
Device Programmers
- PICSTART® Plus Development Programmer
- MPLAB PM3 Device Programmer
- PICkit™ 2 Development Programmer
Low-Cost Demonstration and Development
Boards and Evaluation Kits
26.1 MPLAB Integrated Development
Environment Software
The MPLAB IDE software brings an ease of software
development previously unseen in the 8/16-bit micro-
controller market. The MPLAB IDE is a Windows®
operating system-based application that contains:
A single graphical interface to all debugging tools
- Simulator
- Programmer (sold separately)
- Emulator (sold separately)
- In-Circuit Debugger (sold separately)
A full-featured editor with color-coded context
A multiple project manager
Customizable data windows with direct edit of
contents
High-level source code debugging
Visual device initializer for easy register
initialization
Mouse over variable inspection
Drag and drop variables from source to watch
windows
Extensive on-line help
Integration of select third party tools, such as
HI-TECH Software C Compilers and IAR
C Compilers
The MPLAB IDE allows you to:
Edit your source files (either assembly or C)
One touch assemble (or compile) and download
to PIC MCU emulator and simulator tools
(automatically updates all project information)
Debug using:
- Source files (assembly or C)
- Mixed assembly and C
- Machine code
MPLAB IDE supports multiple debugging tools in a
single development paradigm, from the cost-effective
simulators, through low-cost in-circuit debuggers, to
full-featured emulators. This eliminates the learning
curve when upgrading to tools with increased flexibility
and power.
PIC18F87J11 FAMILY
DS39778C-page 380 Preliminary © 2008 Microchip Technology Inc.
26.2 MPASM Assembler
The MPASM Assembler is a full-featured, universal
macro assembler for all PIC MCUs.
The MPASM Assembler generates relocatable object
files for the MPLINK Object Linker, Intel® standard HEX
files, MAP files to detail memory usage and symbol
reference, absolute LST files that contain source lines
and generated machine code and COFF files for
debugging.
The MPASM Assembler features include:
Integration into MPLAB IDE projects
User-defined macros to streamline
assembly code
Conditional assembly for multi-purpose
source files
Directives that allow complete control over the
assembly process
26.3 MPLAB C18 and MPLAB C30
C Compilers
The MPLAB C18 and MPLAB C30 Code Development
Systems are complete ANSI C compilers for
Microchip’s PIC18 and PIC24 families of microcontrol-
lers and the dsPIC30 and dsPIC33 family of digital sig-
nal controllers. These compilers provide powerful
integration capabilities, superior code optimization and
ease of use not found with other compilers.
For easy source level debugging, the compilers provide
symbol information that is optimized to the MPLAB IDE
debugger.
26.4 MPLINK Object Linker/
MPLIB Object Librarian
The MPLINK Object Linker combines relocatable
objects created by the MPASM Assembler and the
MPLAB C18 C Compiler. It can link relocatable objects
from precompiled libraries, using directives from a
linker script.
The MPLIB Object Librarian manages the creation and
modification of library files of precompiled code. When
a routine from a library is called from a source file, only
the modules that contain that routine will be linked in
with the application. This allows large libraries to be
used efficiently in many different applications.
The object linker/library features include:
Efficient linking of single libraries instead of many
smaller files
Enhanced code maintainability by grouping
related modules together
Flexible creation of libraries with easy module
listing, replacement, deletion and extraction
26.5 MPLAB ASM30 Assembler, Linker
and Librarian
MPLAB ASM30 Assembler produces relocatable
machine code from symbolic assembly language for
dsPIC30F devices. MPLAB C30 C Compiler uses the
assembler to produce its object file. The assembler
generates relocatable object files that can then be
archived or linked with other relocatable object files and
archives to create an executable file. Notable features
of the assembler include:
Support for the entire dsPIC30F instruction set
Support for fixed-point and floating-point data
Command line interface
Rich directive set
Flexible macro language
MPLAB IDE compatibility
26.6 MPLAB SIM Software Simulator
The MPLAB SIM Software Simulator allows code
development in a PC-hosted environment by simulat-
ing the PIC MCUs and dsPIC® DSCs on an instruction
level. On any given instruction, the data areas can be
examined or modified and stimuli can be applied from
a comprehensive stimulus controller. Registers can be
logged to files for further run-time analysis. The trace
buffer and logic analyzer display extend the power of
the simulator to record and track program execution,
actions on I/O, most peripherals and internal registers.
The MPLAB SIM Software Simulator fully supports
symbolic debugging using the MPLAB C18 and
MPLAB C30 C Compilers, and the MPASM and
MPLAB ASM30 Assemblers. The software simulator
offers the flexibility to develop and debug code outside
of the hardware laboratory environment, making it an
excellent, economical software development tool.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 381
PIC18F87J11 FAMILY
26.7 MPLAB ICE 2000
High-Performance
In-Circuit Emulator
The MPLAB ICE 2000 In-Circuit Emulator is intended
to provide the product development engineer with a
complete microcontroller design tool set for PIC
microcontrollers. Software control of the MPLAB ICE
2000 In-Circuit Emulator is advanced by the MPLAB
Integrated Development Environment, which allows
editing, building, downloading and source debugging
from a single environment.
The MPLAB ICE 2000 is a full-featured emulator
system with enhanced trace, trigger and data monitor-
ing features. Interchangeable processor modules allow
the system to be easily reconfigured for emulation of
different processors. The architecture of the MPLAB
ICE 2000 In-Circuit Emulator allows expansion to
support new PIC microcontrollers.
The MPLAB ICE 2000 In-Circuit Emulator system has
been designed as a real-time emulation system with
advanced features that are typically found on more
expensive development tools. The PC platform and
Microsoft® Windows® 32-bit operating system were
chosen to best make these features available in a
simple, unified application.
26.8 MPLAB REAL ICE In-Circuit
Emulator System
MPLAB REAL ICE In-Circuit Emulator System is
Microchip’s next generation high-speed emulator for
Microchip Flash DSC and MCU devices. It debugs and
programs PIC® Flash MCUs and dsPIC® Flash DSCs
with the easy-to-use, powerful graphical user interface of
the MPLAB Integrated Development Environment (IDE),
included with each kit.
The MPLAB REAL ICE probe is connected to the design
engineer’s PC using a high-speed USB 2.0 interface and
is connected to the target with either a connector
compatible with the popular MPLAB ICD 2 system
(RJ11) or with the new high-speed, noise tolerant, Low-
Voltage Differential Signal (LVDS) interconnection
(CAT5).
MPLAB REAL ICE is field upgradeable through future
firmware downloads in MPLAB IDE. In upcoming
releases of MPLAB IDE, new devices will be supported,
and new features will be added, such as software break-
points and assembly code trace. MPLAB REAL ICE
offers significant advantages over competitive emulators
including low-cost, full-speed emulation, real-time
variable watches, trace analysis, complex breakpoints, a
ruggedized probe interface and long (up to three meters)
interconnection cables.
26.9 MPLAB ICD 2 In-Circuit Debugger
Microchip’s In-Circuit Debugger, MPLAB ICD 2, is a
powerful, low-cost, run-time development tool,
connecting to the host PC via an RS-232 or high-speed
USB interface. This tool is based on the Flash PIC
MCUs and can be used to develop for these and other
PIC MCUs and dsPIC DSCs. The MPLAB ICD 2 utilizes
the in-circuit debugging capability built into the Flash
devices. This feature, along with Microchip’s In-Circuit
Serial ProgrammingTM (ICSPTM) protocol, offers cost-
effective, in-circuit Flash debugging from the graphical
user interface of the MPLAB Integrated Development
Environment. This enables a designer to develop and
debug source code by setting breakpoints, single step-
ping and watching variables, and CPU status and
peripheral registers. Running at full speed enables
testing hardware and applications in real time. MPLAB
ICD 2 also serves as a development programmer for
selected PIC devices.
26.10 MPLAB PM3 Device Programmer
The MPLAB PM3 Device Programmer is a universal,
CE compliant device programmer with programmable
voltage verification at VDDMIN and VDDMAX for
maximum reliability. It features a large LCD display
(128 x 64) for menus and error messages and a modu-
lar, detachable socket assembly to support various
package types. The ICSP™ cable assembly is included
as a standard item. In Stand-Alone mode, the MPLAB
PM3 Device Programmer can read, verify and program
PIC devices without a PC connection. It can also set
code protection in this mode. The MPLAB PM3
connects to the host PC via an RS-232 or USB cable.
The MPLAB PM3 has high-speed communications and
optimized algorithms for quick programming of large
memory devices and incorporates an SD/MMC card for
file storage and secure data applications.
PIC18F87J11 FAMILY
DS39778C-page 382 Preliminary © 2008 Microchip Technology Inc.
26.11 PICSTART Plus Development
Programmer
The PICSTART Plus Development Programmer is an
easy-to-use, low-cost, prototype programmer. It
connects to the PC via a COM (RS-232) port. MPLAB
Integrated Development Environment software makes
using the programmer simple and efficient. The
PICSTART Plus Development Programmer supports
most PIC devices in DIP packages up to 40 pins.
Larger pin count devices, such as the PIC16C92X and
PIC17C76X, may be supported with an adapter socket.
The PICSTART Plus Development Programmer is CE
compliant.
26.12 PICkit 2 Development Programmer
The PICkit™ 2 Development Programmer is a low-cost
programmer and selected Flash device debugger with
an easy-to-use interface for programming many of
Microchip’s baseline, mid-range and PIC18F families of
Flash memory microcontrollers. The PICkit 2 Starter Kit
includes a prototyping development board, twelve
sequential lessons, software and HI-TECH’s PICC™
Lite C compiler, and is designed to help get up to speed
quickly using PIC® microcontrollers. The kit provides
everything needed to program, evaluate and develop
applications using Microchip’s powerful, mid-range
Flash memory family of microcontrollers.
26.13 Demonstration, Development and
Evaluation Boards
A wide variety of demonstration, development and
evaluation boards for various PIC MCUs and dsPIC
DSCs allows quick application development on fully func-
tional systems. Most boards include prototyping areas for
adding custom circuitry and provide application firmware
and source code for examination and modification.
The boards support a variety of features, including LEDs,
temperature sensors, switches, speakers, RS-232
interfaces, LCD displays, potentiometers and additional
EEPROM memory.
The demonstration and development boards can be
used in teaching environments, for prototyping custom
circuits and for learning about various microcontroller
applications.
In addition to the PICDEM™ and dsPICDEM™ demon-
stration/development board series of circuits, Microchip
has a line of evaluation kits and demonstration software
for analog filter design, KEELOQ® security ICs, CAN,
IrDA®, PowerSmart battery management, SEEVAL®
evaluation system, Sigma-Delta ADC, flow rate
sensing, plus many more.
Check the Microchip web page (www.microchip.com)
for the complete list of demonstration, development
and evaluation kits.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 383
PIC18F87J11 FAMILY
27.0 ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings(†)
Ambient temperature under bias.............................................................................................................-40°C to +100°C
Storage temperature .............................................................................................................................. -65°C to +150°C
Voltage on any digital only input pin or MCLR with respect to VSS (except VDD) ........................................ -0.3V to 6.0V
Voltage on any combined digital and analog pin with respect to VSS ............................................. -0.3V to (VDD + 0.3V)
Voltage on VDDCORE with respect to VSS................................................................................................... -0.3V to 2.75V
Voltage on VDD with respect to VSS ........................................................................................................... -0.3V to 4.0V
Total power dissipation (Note 1) ...............................................................................................................................1.0W
Maximum current out of VSS pin ...........................................................................................................................300 mA
Maximum current into VDD pin ..............................................................................................................................250 mA
Input clamp current, IIK (VI < 0 or VI > VDD) (Note 2)........................................................................................................ ±0mA
Output clamp current, IOK (VO < 0 or VO > VDD) (Note 2) ................................................................................................ ±0mA
Maximum output current sunk by any PORTB and PORTC I/O pins......................................................................25 mA
Maximum output current sunk by any PORTD, PORTE and PORTJ I/O pins ..........................................................8 mA
Maximum output current sunk by any PORTA, PORTF, PORTG and PORTH I/O pins............................................2 mA
Maximum output current sourced by any PORTB and PORTC I/O pins.................................................................25 mA
Maximum output current sourced by any PORTD, PORTE and PORTJ I/O pins.....................................................8 mA
Maximum output current sourced by any PORTA, PORTF, PORTG and PORTH I/O pins ......................................2 mA
Maximum current sunk by all ports combined.......................................................................................................200 mA
Maximum current sourced by all ports combined..................................................................................................200 mA
Note 1: Power dissipation is calculated as follows:
Pdis = VDD x {IDD IOH} + {(VDD – VOH) x IOH} + (VOL x IOL) + (VTPOUT x ITPOUT)
2: No clamping diodes are present.
NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. This is a stress rating only and functional operation of the device at those or any other conditions above those
indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for
extended periods may affect device reliability.
PIC18F87J11 FAMILY
DS39778C-page 384 Preliminary © 2008 Microchip Technology Inc.
FIGURE 27-1: PIC18F87J11 FAMILY VOLTAGE-FREQUENCY GRAPH, REGULATOR ENABLED
(INDUSTRIAL)
FIGURE 27-2: PIC18F87J11 FAMILY VOLTAGE-FREQUENCY GRAPH, REGULATOR DISABLED
(INDUSTRIAL)(1)
0
Frequency
Voltage (VDD)
4.0V
2.0V
48 MHZ
3.5V
3.0V
2.5V
3.6V
8 MHz
PIC18F87J11 Family
2.35V
Frequency
Voltage (VDDCORE)
3.00V
2.00V
48 MHz
2.75V
2.50V
2.25V
2.7V
8 MHz
2.35V
Note 1: When the on-chip voltage regulator is disabled, VDD and VDDCORE must be maintained so that
VDDCORE VDD 3.6V.
PIC18F87J11 Family
0
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 385
PIC18F87J11 FAMILY
27.1 DC Characteristics: Supply Voltage
PIC18F87J11 Family (Industrial)
PIC18F87J11 Family Family
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
Param
No. Symbol Characteristic Min Typ Max Units Conditions
D001 VDD Supply Voltage VDDCORE
2.0
3.6
3.6
V
V
ENVREG tied to VSS
ENVREG tied to VDD
D001B VDDCORE External Supply for
Microcontroller Core
2.0 2.7 V ENVREG tied to VSS
D001C AVDD Analog Supply Voltage VDD – 0.3 VDD + 0.3 V
D001D AVSS Analog Ground Potential VSS – 0.3 VSS + 0.3 V
D002 VDR RAM Data Retention
Voltage(1)
1.5 V
D003 VPOR VDD Power-on Reset
Voltage
0.7 V See Section 4.3 “Power-on
Reset (POR)” for details
D004 SVDD VDD Rise Rate
to Ensure Internal
Power-on Reset Signal
0.05 V/ms See Section 4.3 “Power-on
Reset (POR)” for details
D005 VBOR Brown-out Reset Voltage —1.8— V
Note 1: This is the limit to which VDD can be lowered in Sleep mode, or during a device Reset, without losing RAM
data.
PIC18F87J11 FAMILY
DS39778C-page 386 Preliminary © 2008 Microchip Technology Inc.
27.2 DC Characteristics: Power-Down and Supply Current
PIC18F87J11 Family (Industrial)
PIC18F87J11 Family
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Power-Down Current (IPD)(1)
All devices 0.5 1.4 μA -40°C
VDD = 2.0V(4)
(Sleep mode)
0.5 1.4 μA +25°C
5.5 10.2 μA +85°C
All devices 0.6 1.5 μA -40°C
VDD = 2.5V(4)
(Sleep mode)
0.6 1.5 μA +25°C
6.8 12.6 μA +85°C
All devices 2.9 7 μA -40°C
VDD = 3.3V(5)
(Sleep mode)
3.6 7 μA +25°C
9.6 19 μA +85°C
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: Standard, low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature
crystals are available at a much higher cost.
4: Voltage regulator disabled (ENVREG = 0, tied to VSS).
5: Voltage regulator enabled (ENVREG = 1, tied to VDD, REGSLP = 1).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 387
PIC18F87J11 FAMILY
Supply Current (IDD)(2,3)
All devices 5 14.2 μA-40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 31 kHz
(RC_RUN mode,
internal oscillator source)
5.5 14.2 μA +25°C
10 19.0 μA +85°C
All devices 6.8 16.5 μA-40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
7.6 16.5 μA +25°C
14 22.4 μA +85°C
All devices 37 84 μA-40°C
51 84 μA +25°C VDD = 3.3V(5)
72 108 μA +85°C
All devices 0.43 0.82 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 1 MHz
(RC_RUN mode,
internal oscillator source)
0.47 0.82 mA +25°C
0.52 0.95 mA +85°C
All devices 0.52 0.98 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
0.57 0.98 mA +25°C
0.63 1.10 mA +85°C
All devices 0.59 0.96 mA -40°C
0.65 0.96 mA +25°C VDD = 3.3V(5)
0.72 1.18 mA +85°C
All devices 0.88 1.45 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 4 MHz
(RC_RUN mode,
internal oscillator source)
1 1.45 mA +25°C
1.1 1.58 mA +85°C
All devices 1.2 1.72 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
1.3 1.72 mA +25°C
1.4 1.85 mA +85°C
All devices 1.3 2.87 mA -40°C
1.4 2.87 mA +25°C VDD = 3.3V(5)
1.5 2.96 mA +85°C
27.2 DC Characteristics: Power-Down and Supply Current
PIC18F87J11 Family (Industrial) (Continued)
PIC18F87J11 Family
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: Standard, low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature
crystals are available at a much higher cost.
4: Voltage regulator disabled (ENVREG = 0, tied to VSS).
5: Voltage regulator enabled (ENVREG = 1, tied to VDD, REGSLP = 1).
PIC18F87J11 FAMILY
DS39778C-page 388 Preliminary © 2008 Microchip Technology Inc.
Supply Current (IDD) Cont.(2,3)
All devices 3 9.4 μA-40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 31 kHz
(RC_IDLE mode,
internal oscillator source)
3.3 9.4 μA +25°C
8.5 17.2 μA +85°C
All devices 4 10.5 μA-40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
4.3 10.5 μA +25°C
10.3 19.5 μA +85°C
All devices 34 82 μA-40°C
48 82 μA +25°C VDD = 3.3V(5)
69 105 μA +85°C
All devices 0.33 0.75 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 1 MHz
(RC_IDLE mode,
internal oscillator source)
0.37 0.75 mA +25°C
0.41 0.84 mA +85°C
All devices 0.39 0.78 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
0.42 0.78 mA +25°C
0.47 0.91 mA +85°C
All devices 0.43 0.82 mA -40°C
0.48 0.82 mA +25°C VDD = 3.3V(5)
0.54 0.95 mA +85°C
All devices 0.53 0.98 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 4 MHz
(RC_IDLE mode,
internal oscillator source)
0.57 0.98 mA +25°C
0.61 1.12 mA +85°C
All devices 0.63 1.14 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
0.67 1.14 mA +25°C
0.72 1.25 mA +85°C
All devices 0.7 1.27 mA -40°C
0.76 1.27 mA +25°C VDD = 3.3V(5)
0.82 1.45 mA +85°C
27.2 DC Characteristics: Power-Down and Supply Current
PIC18F87J11 Family (Industrial) (Continued)
PIC18F87J11 Family
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: Standard, low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature
crystals are available at a much higher cost.
4: Voltage regulator disabled (ENVREG = 0, tied to VSS).
5: Voltage regulator enabled (ENVREG = 1, tied to VDD, REGSLP = 1).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 389
PIC18F87J11 FAMILY
Supply Current (IDD) Cont.(2,3)
All devices 0.17 0.35 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 1 MHZ
(PRI_RUN mode,
EC oscillator)
0.18 0.35 mA +25°C
0.20 0.42 mA +85°C
All devices 0.29 0.52 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
0.31 0.52 mA +25°C
0.34 0.61 mA +85°C
All devices 0.59 1.1 mA -40°C
0.44 0.85 mA +25°C VDD = 3.3V(5)
0.42 0.85 mA +85°C
All devices 0.70 1.25 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 4 MHz
(PRI_RUN mode,
EC oscillator)
0.75 1.25 mA +25°C
0.79 1.36 mA +85°C
All devices 1.10 1.7 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
1.10 1.7 mA +25°C
1.12 1.82 mA +85°C
All devices 1.55 1.95 mA -40°C
1.47 1.89 mA +25°C VDD = 3.3V(5)
1.54 1.92 mA +85°C
All devices 9.9 14.8 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
FOSC = 48 MHZ
(PRI_RUN mode,
EC oscillator)
9.5 14.8 mA +25°C
10.1 15.2 mA +85°C
All devices 13.3 23.2 mA -40°C
12.2 22.7 mA +25°C VDD = 3.3V(5)
12.1 22.7 mA +85°C
27.2 DC Characteristics: Power-Down and Supply Current
PIC18F87J11 Family (Industrial) (Continued)
PIC18F87J11 Family
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: Standard, low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature
crystals are available at a much higher cost.
4: Voltage regulator disabled (ENVREG = 0, tied to VSS).
5: Voltage regulator enabled (ENVREG = 1, tied to VDD, REGSLP = 1).
PIC18F87J11 FAMILY
DS39778C-page 390 Preliminary © 2008 Microchip Technology Inc.
Supply Current (IDD) Cont.(2,3)
All devices 4.5 5.2 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
FOSC = 4 MHZ,
16 MHz internal
(PRI_RUN HSPLL mode)
4.4 5.2 mA +25°C
4.5 5.2 mA +85°C
All devices 5.7 6.7 mA -40°C
VDD = 3.3V(5)
5.5 6.3 mA +25°C
5.3 6.3 mA +85°C
All devices 10.8 13.5 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
FOSC = 10 MHZ,
40 MHz internal
(PRI_RUN HSPLL mode)
10.8 13.5 mA +25°C
9.9 13.0 mA +85°C
All devices 13.4 24.1 mA -40°C
VDD = 3.3V(5)
12.3 20.2 mA +25°C
11.2 19.5 mA +85°C
27.2 DC Characteristics: Power-Down and Supply Current
PIC18F87J11 Family (Industrial) (Continued)
PIC18F87J11 Family
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: Standard, low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature
crystals are available at a much higher cost.
4: Voltage regulator disabled (ENVREG = 0, tied to VSS).
5: Voltage regulator enabled (ENVREG = 1, tied to VDD, REGSLP = 1).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 391
PIC18F87J11 FAMILY
Supply Current (IDD) Cont.(2,3)
All devices 0.10 0.26 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 1 MHz
(PRI_IDLE mode,
EC oscillator)
0.07 0.18 mA +25°C
0.09 0.22 mA +85°C
All devices 0.25 0.48 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
0.13 0.30 mA +25°C
0.10 0.26 mA +85°C
All devices 0.45 0.68 mA -40°C
0.26 0.45 mA +25°C VDD = 3.3V(5)
0.30 0.54 mA +85°C
All devices 0.36 0.60 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 4 MHz
(PRI_IDLE mode,
EC oscillator)
0.33 0.56 mA +25°C
0.35 0.56 mA +85°C
All devices 0.52 0.81 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
0.45 0.70 mA +25°C
0.46 0.70 mA +85°C
All devices 0.80 1.15 mA -40°C
0.66 0.98 mA +25°C VDD = 3.3V(5)
0.65 0.98 mA +85°C
All devices 5.2 6.5 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
FOSC = 48 MHz
(PRI_IDLE mode,
EC oscillator)
4.9 5.9 mA +25°C
3.4 4.5 mA +85°C
All devices 6.2 12.4 mA -40°C
5.9 11.5 mA +25°C VDD = 3.3V(5)
5.8 11.5 mA +85°C
27.2 DC Characteristics: Power-Down and Supply Current
PIC18F87J11 Family (Industrial) (Continued)
PIC18F87J11 Family
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: Standard, low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature
crystals are available at a much higher cost.
4: Voltage regulator disabled (ENVREG = 0, tied to VSS).
5: Voltage regulator enabled (ENVREG = 1, tied to VDD, REGSLP = 1).
PIC18F87J11 FAMILY
DS39778C-page 392 Preliminary © 2008 Microchip Technology Inc.
Supply Current (IDD) Cont.(2,3)
All devices 18 35 µA -40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 32 kHz(3)
(SEC_RUN mode,
Timer1 as clock)
19 35 µA +25°C
28 49 µA +85°C
All devices 20 45 µA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
21 45 µA +25°C
32 61 µA +85°C
All devices 0.06 0.11 mA -40°C
0.07 0.11 mA +25°C VDD = 3.3V(5)
0.09 0.15 mA +85°C
All devices 14 28 µA -40°C
VDD = 2.0V,
VDDCORE = 2.0V(4)
FOSC = 32 kHz(3)
(SEC_IDLE mode,
Timer1 as clock)
15 28 µA +25°C
24 43 µA +85°C
All devices 15 31 µA -40°C
VDD = 2.5V,
VDDCORE = 2.5V(4)
16 31 µA +25°C
27 50 µA +85°C
All devices 0.05 0.10 mA -40°C
0.06 0.10 mA +25°C VDD = 3.3V(5)
0.08 0.14 mA +85°C
27.2 DC Characteristics: Power-Down and Supply Current
PIC18F87J11 Family (Industrial) (Continued)
PIC18F87J11 Family
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: Standard, low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature
crystals are available at a much higher cost.
4: Voltage regulator disabled (ENVREG = 0, tied to VSS).
5: Voltage regulator enabled (ENVREG = 1, tied to VDD, REGSLP = 1).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 393
PIC18F87J11 FAMILY
D022 Module Differential Currents (ΔIWDT, ΔIOSCB, ΔIAD)
Watchdog Timer 2.1 7.0 μA-40°C VDD = 2.0V,
VDDCORE = 2.0V(4)
2.2 7.0 μA +25°C
4.3 9.5 μA +85°C
3.0 8.0 μA-40°C VDD = 2.5V,
VDDCORE = 2.5V(4)
3.1 8.0 μA +25°C
5.5 10.4 μA +85°C
5.9 12.1 μA-40°C
VDD = 3.3V
6.2 12.1 μA +25°C
6.9 13.6 μA +85°C
D025
(ΔIOSCB)
Timer1 Oscillator 14 24 μA-40°C VDD = 2.0V,
VDDCORE = 2.0V(4) 32 kHz on Timer1(3)
15 24 μA +25°C
23 36 μA +85°C
17 26 μA-40°C VDD = 2.5V,
VDDCORE = 2.5V(4) 32 kHz on Timer1(3)
18 26 μA +25°C
25 38 μA +85°C
19 35 μA-40°C
VDD = 3.3V 32 kHz on Timer1(3)
21 35 μA +25°C
28 44 μA +85°C
D026
(ΔIAD)
A/D Converter 3.0 10.0 μA -40°C to +85°C VDD = 2.0V,
VDDCORE = 2.0V(4)
A/D on, not converting
3.0 10.0 μA -40°C to +85°C VDD = 2.5V,
VDDCORE = 2.5V(4)
3.2 11.0 μA -40°C to +85°C VDD = 3.3V
27.2 DC Characteristics: Power-Down and Supply Current
PIC18F87J11 Family (Industrial) (Continued)
PIC18F87J11 Family
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: Standard, low-cost 32 kHz crystals have an operating temperature range of -10°C to +70°C. Extended temperature
crystals are available at a much higher cost.
4: Voltage regulator disabled (ENVREG = 0, tied to VSS).
5: Voltage regulator enabled (ENVREG = 1, tied to VDD, REGSLP = 1).
PIC18F87J11 FAMILY
DS39778C-page 394 Preliminary © 2008 Microchip Technology Inc.
27.3 DC Characteristics:PIC18F87J11 Family (Industrial)
DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Symbol Characteristic Min Max Units Conditions
VIL Input Low Voltage
All I/O Ports:
D030 with TTL Buffer VSS 0.15 VDD V
D031 with Schmitt Trigger Buffer VSS 0.2 VDD V
D032 MCLR VSS 0.2 VDD V
D033 OSC1 VSS 0.3 VDD V HS, HSPLL modes
D033A
D034
OSC1
T13CKI
VSS
VSS
0.2 VDD
0.3
V
V
EC, ECPLL modes
VIH Input High Voltage
I/O Ports with Analog Functions:
D040 with TTL Buffer 0.25 VDD + 0.8V VDD VVDD < 3.3V
D041 with Schmitt Trigger Buffer 0.8 VDD VDD V
Digital-only I/O Ports:
with TTL Buffer 0.25 VDD + 0.8V 5.5 V VDD < 3.3V
2.0 5.5 V 3.3V VDD 3.6V
with Schmitt Trigger Buffer 0.8 VDD 5.5 V
D042 MCLR 0.8 VDD VDD V
D043 OSC1 0.7 VDD VDD V HS, HSPLL modes
D043A
D044
OSC1
T13CKI
0.8 VDD
1.6
VDD
VDD
V
V
EC, ECPLL modes
IIL Input Leakage Current(1,2)
D060 I/O Ports ±1μAVSS VPIN VDD,
Pin at high-impedance
D061 MCLR ±1μAVss VPIN VDD
D063 OSC1 ±5μAVss VPIN VDD
IPU Weak Pull-up Current
D070 IPURB PORTB Weak Pull-up Current 80 400 μAVDD = 3.3V, VPIN = VSS
Note 1: Negative current is defined as current sourced by the pin.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 395
PIC18F87J11 FAMILY
VOL Output Low Voltage
D080 I/O Ports:
PORTA, PORTF, PORTG,
PORTH
—0.4VI
OL = 2 mA, VDD = 3.3V,
-40°C to +85°C
PORTD, PORTE, PORTJ 0.4 V IOL = 3.4 mA, VDD = 3.3V,
-40°C to +85°C
PORTB, PORTC 0.4 V IOL = 3.4 mA, VDD = 3.3V,
-40°C to +85°C
D083 OSC2/CLKO
(EC, ECPLL modes)
—0.4VI
OL = 1.6 mA, VDD = 3.3V,
-40°C to +85°C
VOH Output High Voltage(1)
D090 I/O Ports: V
PORTA, PORTF, PORTG,
PORTH
2.4 V IOH = -2 mA, VDD = 3.3V,
-40°C to +85°C
PORTD, PORTE, PORTJ 2.4 V IOH = -2 mA, VDD = 3.3V,
-40°C to +85°C
PORTB, PORTC 2.4 V IOH = -2 mA, VDD = 3.3V,
-40°C to +85°C
D092 OSC2/CLKO
(INTOSC, EC, ECPLL modes)
2.4 V IOH = -1 mA, VDD = 3.3V,
-40°C to +85°C
Capacitive Loading Specs
on Output Pins
D100(4) COSC2 OSC2 pin 15 pF In HS mode when
external clock is used to drive
OSC1
D101 CIO All I/O pins and OSC2 50 pF To meet the AC Timing
Specifications
D102 CBSCLx, SDAx 400 pF I2C™ Specification
27.3 DC Characteristics:PIC18F87J11 Family (Industrial) (Continued)
DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Symbol Characteristic Min Max Units Conditions
Note 1: Negative current is defined as current sourced by the pin.
PIC18F87J11 FAMILY
DS39778C-page 396 Preliminary © 2008 Microchip Technology Inc.
TABLE 27-1: MEMORY PROGRAMMING REQUIREMENTS
DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Sym Characteristic Min Typ† Max Units Conditions
Program Flash Memory
D130 EPCell Endurance 10K E/W -40°C to +85°C
D131 VPR VDD for Read VMIN —3.6VVMIN = Minimum operating
voltage
D132B VPEW VDD for Self-Timed Write VMIN —3.6VVMIN = Minimum operating
voltage
D133A TIW Self-Timed Write Cycle Time 2.8 ms
D134 TRETD Characteristic Retention 20 Year Provided no other
specifications are violated
D135 IDDP Supply Current during
Programming
—314mA
D1xxx TWE Writes per Erase Cycle 1
Data in “Typ” column is at 3.3V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 397
PIC18F87J11 FAMILY
TABLE 27-2: COMPARATOR SPECIFICATIONS
TABLE 27-3: VOLTAGE REFERENCE SPECIFICATIONS
TABLE 27-4: INTERNAL VOLTAGE REGULATOR SPECIFICATIONS
Operating Conditions: 3.0V < VDD < 3.6V, -40°C < TA < +85°C (unless otherwise stated)
Param
No. Sym Characteristics Min Typ Max Units Comments
D300 VIOFF Input Offset Voltage ±5.0 ±10 mV
D301 VICM Input Common Mode Voltage* 0 AVDD – 1.5 V
VIRV Internal Reference Voltage ±1.2(2) —V±1.2%
D302 CMRR Common Mode Rejection Ratio* 55 dB
300 TRESP Response Time(1)* —150400 ns
301 TMC2OV Comparator Mode Change to
Output Valid*
—— 10 μs
* These parameters are characterized but not tested.
Note 1: Response time measured with one comparator input at (VDD 1.5)/2, while the other input transitions
from VSS to VDD.
2: Tolerance is ±1.2%.
Operating Conditions: 3.0V < VDD < 3.6V, -40°C < TA < +85°C (unless otherwise stated)
Param
No. Sym Characteristics Min Typ Max Units Comments
D310 VRES Resolution VDD/24 VDD/32 LSb
D311 VRAA Absolute Accuracy 1/2 LSb
D312 VRUR Unit Resistor Value (R) 2k Ω
310 TSET Settling Time(1) — — 10 μs
Note 1: Settling time measured while CVRR = 1 and the CVR3:CVR0 bits transition from ‘0000’ to ‘1111’.
Operating Conditions: -40°C < TA < +85°C (unless otherwise stated)
Param
No. Sym Characteristics Min Typ Max Units Comments
VRGOUT Regulator Output Voltage* 2.5 V
CFExternal Filter Capacitor Value* 4.7 10 μF Capacitor must be low-ESR
* These parameters are characterized but not tested. Parameter numbers not yet assigned for these
specifications.
PIC18F87J11 FAMILY
DS39778C-page 398 Preliminary © 2008 Microchip Technology Inc.
27.4 AC (Timing) Characteristics
27.4.1 TIMING PARAMETER SYMBOLOGY
The timing parameter symbols have been created
following one of the following formats:
1. TppS2ppS 3. TCC:ST (I2C specifications only)
2. TppS 4. Ts (I2C specifications only)
T
F Frequency T Time
Lowercase letters (pp) and their meanings:
pp
cc CCP1 osc OSC1
ck CLKO rd RD
cs CS rw RD or WR
di SDI sc SCK
do SDO ss SS
dt Data in t0 T0CKI
io I/O port t1 T13CKI
mc MCLR wr WR
Uppercase letters and their meanings:
S
F Fall P Period
HHigh RRise
I Invalid (High-impedance) V Valid
L Low Z High-impedance
I2C only
AA output access High High
BUF Bus free Low Low
T
CC:ST (I2C specifications only)
CC
HD Hold SU Setup
ST
DAT DATA input hold STO Stop condition
STA Start condition
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 399
PIC18F87J11 FAMILY
27.4.2 TIMING CONDITIONS
The temperature and voltages specified in Table 27-5
apply to all timing specifications unless otherwise
noted. Figure 27-3 specifies the load conditions for the
timing specifications.
TABLE 27-5: TEMPERATURE AND VOLTAGE SPECIFICATIONS – AC
FIGURE 27-3: LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS
AC CHARACTERISTICS
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
Operating voltage VDD range as described in Section 27.1 and Section 27.3.
VDD/2
CL
RL
Pin Pin
VSS VSS
CL
RL=464Ω
CL= 50 pF for all pins except OSC2/CLKO/RA6
and including D and E outputs as ports
CL= 15 pF for OSC2/CLKO/RA6
Load Condition 1 Load Condition 2
PIC18F87J11 FAMILY
DS39778C-page 400 Preliminary © 2008 Microchip Technology Inc.
27.4.3 TIMING DIAGRAMS AND SPECIFICATIONS
FIGURE 27-4: EXTERNAL CLOCK TIMING
TABLE 27-6: EXTERNAL CLOCK TIMING REQUIREMENTS
OSC1
CLKO
Q4 Q1 Q2 Q3 Q4 Q1
1
2
3344
Param.
No. Symbol Characteristic Min Max Units Conditions
1A FOSC External CLKI Frequency(1) DC 48 MHz EC Oscillator mode
DC 10 ECPLL Oscillator mode
Oscillator Frequency(1) 4 25 MHz HS Oscillator mode
4 10 HSPLL Oscillator mode
1T
OSC External CLKI Period(1) 20.8 ns EC Oscillator mode
100 ECPLL Oscillator mode
Oscillator Period(1) 40.0 250 ns HS Oscillator mode
100 250 HSPLL Oscillator mode
2T
CY Instruction Cycle Time(1) 83.3 ns TCY = 4/FOSC, Industrial
3TOSL,
TOSH
External Clock in (OSC1)
High or Low Time
10 ns HS Oscillator mode
4T
OSR,
TOSF
External Clock in (OSC1)
Rise or Fall Time
7.5 ns HS Oscillator mode
Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period for all configurations
except PLL. All specified values are based on characterization data for that particular oscillator type under
standard operating conditions with the device executing code. Exceeding these specified limits may result
in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested
to operate at “min.” values with an external clock applied to the OSC1/CLKI pin. When an external clock
input is used, the “max.” cycle time limit is “DC” (no clock) for all devices.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 401
PIC18F87J11 FAMILY
TABLE 27-7: PLL CLOCK TIMING SPECIFICATIONS (VDD = 2.15V TO 3.6V)
TABLE 27-8: INTERNAL RC ACCURACY (INTOSC AND INTRC SOURCES)
Param
No. Sym Characteristic Min Typ† Max Units Conditions
F10 FOSC Oscillator Frequency Range 4 10 MHz
F11 FSYS On-Chip VCO System Frequency 16 40 MHz
F12 trc PLL Start-up Time (lock time) 2 ms
F13 ΔCLK CLKO Stability (jitter) -2 +2 %
Data in “Typ” column is at 3.3V, 25°C, unless otherwise stated. These parameters are for design guidance
only and are not tested.
Param
No. Device Min Typ Max Units Conditions
INTOSC Accuracy @ Freq = 8 MHz, 4 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz, 125 kHz, 31 kHz(1)
All Devices -2 +/-1 2 % +25°C VDD = 2.7-3.3V
-5 5 % -10°C to +85°C VDD = 2.0-3.3V
-10 +/-1 10 % -40°C to +85°C VDD = 2.0-3.3V
INTRC Accuracy @ Freq = 31 kHz(1)
All Devices 21.7 40.3 kHz
Note 1: The accuracy specification of the 31 kHz clock is determined by which source is providing it at a given time.
When INTSRC (OSCTUNE<7>) is 1’, use the INTOSC accuracy specification. When INTSRC is 0’, use
the INTRC accuracy specification.
PIC18F87J11 FAMILY
DS39778C-page 402 Preliminary © 2008 Microchip Technology Inc.
FIGURE 27-5: CLKO AND I/O TIMING
TABLE 27-9: CLKO AND I/O TIMING REQUIREMENTS
Note: Refer to Figure 27-3 for load conditions.
OSC1
CLKO
I/O pin
(Input)
I/O pin
(Output)
Q4 Q1 Q2 Q3
10
13 14
17
20, 21
19 18
15
11
12
16
Old Value New Value
Param
No. Symbol Characteristic Min Typ Max Units Conditions
10 TOSH2CKLOSC1 to CLKO 75 200 ns (Note 1)
11 TOSH2CKHOSC1 to CLKO 75 200 ns (Note 1)
12 TCKRCLKO Rise Time 15 30 ns(Note 1)
13 TCKFCLKO Fall Time 15 30 ns(Note 1)
14 TCKL2IOVCLKO to Port Out Valid 0.5 TCY + 20 ns
15 TIOV2CKH Port In Valid before CLKO 0.25 TCY + 25 ns
16 TCKH2IOI Port In Hold after CLKO 0—ns
17 TOSH2IOVOSC1 (Q1 cycle) to Port Out Valid 50 150 ns
18 TOSH2IOIOSC1 (Q2 cycle) to Port Input Invalid
(I/O in hold time)
100 ns
19 TIOV2OSH Port Input Valid to OSC1
(I/O in setup time)
0—ns
20 TIOR Port Output Rise Time 6 ns
21 TIOF Port Output Fall Time 5 ns
22† TINP INTx pin High or Low Time TCY ——ns
23† TRBP RB7:RB4 Change INTx High or Low Time TCY ——ns
These parameters are asynchronous events not related to any internal clock edges.
Note 1: Measurements are taken in EC mode, where CLKO output is 4 x TOSC.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 403
PIC18F87J11 FAMILY
FIGURE 27-6: PROGRAM MEMORY READ TIMING DIAGRAM
TABLE 27-10: CLKO AND I/O TIMING REQUIREMENTS
Param.
No Symbol Characteristics Min Typ Max Units
150 TadV2alL Address Out Valid to ALE
(address setup time)
0.25 TCY – 10 ns
151 TalL2adl ALE to Address Out Invalid
(address hold time)
5—ns
155 TalL2oeL ALE to OE 10 0.125 TCY —ns
160 TadZ2oeL AD high-Z to OE (bus release to OE)0ns
161 ToeH2adD OE to AD Driven 0.125 TCY – 5 ns
162 TadV2oeH Least Significant Data Valid before OE
(data setup time)
20 ns
163 ToeH2adl OE to Data In Invalid (data hold time) 0 ns
164 TalH2alL ALE Pulse Width 0.25 TCY —ns
165 ToeL2oeH OE Pulse Width 0.5 TCY – 5 0.5 TCY —ns
166 TalH2alH ALE to ALE (cycle time) TCY —ns
167 Tacc Address Valid to Data Valid 0.75 TCY – 25 ns
168 Toe OE to Data Valid 0.5 TCY – 25 ns
169 TalL2oeH ALE to OE 0.625 TCY – 10 0.625 TCY + 10 ns
171 TalH2csL Chip Enable Active to ALE 0.25 TCY – 20 ns
171A TubL2oeH AD Valid to Chip Enable Active 10 ns
Address
Q1 Q2 Q3 Q4 Q1 Q2
OSC1
ALE
OE
166
160
165
161
151 162
163
AD<15:0>
167
168
155
Address
Address
150
A<19:16> Address
169
BA0
CE
171
171A
Operating Conditions: 2.0V < VCC < 3.6V, -40°C < TA < +125°C unless otherwise stated.
164
Data from External
PIC18F87J11 FAMILY
DS39778C-page 404 Preliminary © 2008 Microchip Technology Inc.
FIGURE 27-7: PROGRAM MEMORY WRITE TIMING DIAGRAM
TABLE 27-11: PROGRAM MEMORY WRITE TIMING REQUIREMENTS
Param.
No Symbol Characteristics Min Typ Max Units
150 TadV2alL Address Out Valid to ALE (address setup time) 0.25 TCY – 10 ns
151 TalL2adl ALE to Address Out Invalid (address hold time) 5 ns
153 TwrH2adl WRn to Data Out Invalid (data hold time) 5 ns
154 TwrL WRn Pulse Width 0.5 TCY – 5 0.5 TCY —ns
156 TadV2wrH Data Valid before WRn (data setup time) 0.5 TCY – 10 ns
157 TbsV2wrL Byte Select Valid before WRn
(byte select setup time)
0.25 TCY ——ns
157A TwrH2bsI WRn to Byte Select Invalid (byte select hold time) 0.125 TCY – 5 ns
166 TalH2alH ALE to ALE (cycle time) TCY —ns
171 TalH2csL Chip Enable Active to ALE 0.25 TCY – 20 ns
171A TubL2oeH AD Valid to Chip Enable Active 10 ns
Address
Q1 Q2 Q3 Q4 Q1 Q2
OSC1
ALE
Data
156
150
151
153
AD<15:0> Address
WRH or
WRL
UB or
LB
157
154
157A
Address
A<19:16> Address
BA0
166
CE
171
171A
Operating Conditions: 2.0V < VCC < 3.6V, -40°C < TA < +125°C unless otherwise stated.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 405
PIC18F87J11 FAMILY
FIGURE 27-8: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND
POWER-UP TIMER TIMING
TABLE 27-12: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
Param.
No. Symbol Characteristic Min Typ Max Units Conditions
30 TMCLMCLR Pulse Width (low) 2 TCY (Note 1)
31 TWDT Watchdog Timer Time-out Period
(no postscaler)
3.4 4.0 4.6 ms
32 TOST Oscillator Start-up Timer Period 1024 TOSC 1024 TOSC —TOSC = OSC1 period
33 TPWRT Power-up Timer Period 45.8 65.5 85.2 ms
34 TIOZ I/O High-Impedance from MCLR
Low or Watchdog Timer Reset
—2μs
38 TCSD CPU Start-up Time 200 μs
Note 1: To ensure device reset, MCLR must be low for at least 2 TCY or 400 µs, whichever is lower.
VDD
MCLR
Internal
POR
PWRT
Time-out
Oscillator
Time-out
Internal
Reset
Watchdog
Timer
Reset
33
32
30
31
34
I/O pins
34
Note: Refer to Figure 27-3 for load conditions.
PIC18F87J11 FAMILY
DS39778C-page 406 Preliminary © 2008 Microchip Technology Inc.
TABLE 27-13: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
TABLE 27-14: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Note: Refer to Figure 27-3 for load conditions.
46
47
45
48
41
42
40
T0CKI
T1OSO/T13CKI
TMR0 or
TMR1
Param
No. Symbol Characteristic Min Max Units Conditions
40 TT0H T0CKI High Pulse Width No prescaler 0.5 TCY + 20 ns
With prescaler 10 ns
41 TT0L T0CKI Low Pulse Width No prescaler 0.5 TCY + 20 ns
With prescaler 10 ns
42 TT0P T0CKI Period No prescaler TCY + 10 ns
With prescaler Greater of:
20 ns or
(TCY + 40)/N
—nsN = prescale
value
(1, 2, 4,..., 256)
45 TT1H T13CKI High
Time
Synchronous, no prescaler 0.5 TCY + 20 ns
Synchronous, with prescaler 10 ns
Asynchronous 30 ns
46 TT1L T13CKI Low
Time
Synchronous, no prescaler 0.5 TCY + 5 ns
Synchronous, with prescaler 10 ns
Asynchronous 30 ns
47 TT1P T13CKI Input
Period
Synchronous Greater of:
20 ns or
(TCY + 40)/N
—nsN = prescale
value
(1, 2, 4, 8)
Asynchronous 60 ns
FT1 T13CKI Oscillator Input Frequency Range DC 50 kHz
48 T
CKE2TMRI Delay from External T13CKI Clock Edge to
Timer Increment
2 TOSC 7 TOSC
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 407
PIC18F87J11 FAMILY
FIGURE 27-9: PARALLEL SLAVE PORT TIMING
TABLE 27-15: PARALLEL SLAVE PORT REQUIREMENTS
PMCSx
PMRD
PMWR
PMD<7:0>
PS1
PS2
PS3
PS4
Note: Refer to Figure 27-3 for load conditions.
Param.
No. Symbol Characteristic Min Max Units Conditions
PS1 TdtV2wrH Data In Valid before PMWR or PMCSx Inactive
(setup time)
20 ns
PS2 TwrH2dtI PMWR or PMCSx Inactive to Data–In Invalid
(hold time)
20 ns
PS3 TrdL2dtV PMRD and PMCSx Active to Data–Out Valid 80 ns
PS4 TrdH2dtI PMRD Active or PMCSx Inactive to Data–Out
Invalid
10 30 ns
PIC18F87J11 FAMILY
DS39778C-page 408 Preliminary © 2008 Microchip Technology Inc.
FIGURE 27-10: PARALLEL MASTER PORT READ TIMING DIAGRAM
TABLE 27-16: PARALLEL MASTER PORT READ TIMING REQUIREMENTS
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2
System
PMALL/
PMD<7:0>
Address
PMA<18:13>
Operating Conditions: 2.0V < VCC < 3.6V, -40°C < TA < +85°C unless otherwise stated.
PMWR
PMCS<2:1>
PMRD
Clock
PM2
PM3
PM6
PM7
PM5
PM1
Data
PMALH
Address<7:0>
Param.
No Symbol Characteristics Min Typ Max Units
PM1 PMALL/PMALH Pulse Width 0.5 TCY —ns
PM2 Address out valid to PMALL/PMALH Invalid
(address setup time)
—0.75 T
CY —ns
PM3 PMALL/PMALH Invalid to Address Out
Invalid (address hold time)
0.25 TCY —ns
PM5 PMRD Pulse Width 0.5 TCY —ns
PM6 PMRD or PMENB Active to Data In Valid
(data setup time)
———ns
PM7 PMRD or PMENB Inactive to Data In Invalid
(data hold time)
———ns
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 409
PIC18F87J11 FAMILY
FIGURE 27-11: PARALLEL MASTER PORT WRITE TIMING DIAGRAM
TABLE 27-17: PARALLEL MASTER PORT WRITE TIMING REQUIREMENTS
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2
System
PMALL/
PMD<7:0>
Address
PMA<18:13>
Operating Conditions: 2.0V < VCC < 3.6V, -40°C < TA < +85°C unless otherwise stated.
PMWR
PMCS<2:1>
PMRD
Clock
PM12 PM13
PM11
PM16
Data
Address<7:0>
PMALH
Param.
No Symbol Characteristics Min Typ Max Units
PM11 PMWR Pulse Width 0.5 T
CY —ns
PM12 Data Out Valid before PMWR or PMENB
Goes Inactive (data setup time)
———ns
PM13 PMWR or PMEMB Invalid to Data Out
Invalid (data hold time)
———ns
PM16 PMCSx Pulse Width T
CY – 5 ns
PIC18F87J11 FAMILY
DS39778C-page 410 Preliminary © 2008 Microchip Technology Inc.
FIGURE 27-12: CAPTURE/COMPARE/PWM TIMINGS (INCLUDING ECCP MODULES)
TABLE 27-18: CAPTURE/COMPARE/PWM REQUIREMENTS (INCLUDING ECCP MODULES)
Note: Refer to Figure 27-3 for load conditions.
CCPx
(Capture Mode)
50 51
52
CCPx
53 54
(Compare or PWM Mode)
Param
No. Symbol Characteristic Min Max Units Conditions
50 TCCL CCPx Input Low
Time
No prescaler 0.5 TCY + 20 ns
With prescaler 10 ns
51 TCCH CCPx Input
High Time
No prescaler 0.5 TCY + 20 ns
With prescaler 10 ns
52 TCCP CCPx Input Period 3 TCY + 40
N
ns N = prescale
value (1, 4 or 16)
53 TCCR CCPx Output Fall Time 25 ns
54 TCCF CCPx Output Fall Time 25 ns
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 411
PIC18F87J11 FAMILY
FIGURE 27-13: EXAMPLE SPI MASTER MODE TIMING (CKE = 0)
TABLE 27-19: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0)
SCKx
(CKP = 0)
SCKx
(CKP = 1)
SDOx
SDIx
73
74
75, 76
78
79
80
79
78
MSb LSbbit 6 - - - - - - 1
LSb In
bit 6 - - - - 1
Note: Refer to Figure 27-3 for load conditions.
MSb In
Param
No. Symbol Characteristic Min Max Units Conditions
73 TDIV2SCH,
TDIV2SCL
Setup Time of SDIx Data Input to SCKx Edge 100 ns
73A TB2BLast Clock Edge of Byte 1 to the 1st Clock Edge
of Byte 2
1.5 TCY + 40 ns
75 TDOR SDOx Data Output Rise Time 25 ns
76 TDOF SDOx Data Output Fall Time 25 ns
78 T
SCR SCKx Output Rise Time 25 ns
79 T
SCF SCKx Output Fall Time 25 ns
80 T
SCH2DOV,
T
SCL2DOV
SDOx Data Output Valid after SCKx Edge 50 ns
PIC18F87J11 FAMILY
DS39778C-page 412 Preliminary © 2008 Microchip Technology Inc.
FIGURE 27-14: EXAMPLE SPI MASTER MODE TIMING (CKE = 1)
TABLE 27-20: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1)
SCKx
(CKP = 0)
SCKx
(CKP = 1)
SDOx
SDIx
81
74
75, 76
78
80
MSb
79
73
bit 6 - - - - - - 1
LSb In
bit 6 - - - - 1
LSb
Note: Refer to Figure 27-3 for load conditions.
MSb In
Param.
No. Symbol Characteristic Min Max Units Conditions
73 TDIV2SCH,
TDIV2SCL
Setup Time of SDIx Data Input to SCKx Edge 100 ns
74 TSCH2DIL,
T
SCL2DIL
Hold Time of SDIx Data Input to SCKx Edge 100 ns
75 TDOR SDOx Data Output Rise Time 25 ns
76 TDOF SDOx Data Output Fall Time 25 ns
78 T
SCR SCKx Output Rise Time 25 ns
79 T
SCF SCKx Output Fall Time 25 ns
80 T
SCH2DOV,
T
SCL2DOV
SDOx Data Output Valid after SCKx Edge 50 ns
81 TDOV2SCH,
TDOV2SCL
SDOx Data Output Setup to SCKx Edge T
CY —ns
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 413
PIC18F87J11 FAMILY
FIGURE 27-15: EXAMPLE SPI SLAVE MODE TIMING (CKE = 0)
TABLE 27-21: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING, CKE = 0)
Param
No. Symbol Characteristic Min Max Units Conditions
70 T
SSL2SCH,
T
SSL2SCL
SSx to SCKx or SCKx Input 3 TCY —ns
70A TSSL2WB SSx to write to SSPxBUF 3 TCY —ns
71 TSCH SCKx Input High Time Continuous 1.25 TCY + 30 ns
71A Single byte 40 ns (Note 1)
72 T
SCL SCKx Input Low Time Continuous 1.25 TCY + 30 ns
72A Single byte 40 ns (Note 1)
73 TDIV2SCH,
TDIV2SCL
Setup Time of SDIx Data Input to SCKx Edge 100 ns
73A TB2BLast Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40 ns (Note 2)
74 TSCH2DIL,
T
SCL2DIL
Hold Time of SDIx Data Input to SCKx Edge 100 ns
75 TDOR SDOx Data Output Rise Time 25 ns
76 TDOF SDOx Data Output Fall Time 25 ns
77 T
SSH2DOZ SSx to SDOx Output High-Impedance 10 50 ns
80 T
SCH2DOV,
T
SCL2DOV
SDOx Data Output Valid after SCKx Edge 50 ns
83 T
SCH2SSH,
T
SCL2SSH
SSx after SCKx Edge 1.5 TCY + 40 ns
Note 1: Requires the use of Parameter #73A.
2: Only if Parameter #71A and #72A are used.
SSx
SCKx
(CKP = 0)
SCKx
(CKP = 1)
SDOx
SDI
70
71 72
73
74
75, 76 77
80
MSb LSb
bit 6 - - - - - - 1
bit 6 - - - - 1 LSb In
83
Note: Refer to Figure 27-3 for load conditions.
MSb In
PIC18F87J11 FAMILY
DS39778C-page 414 Preliminary © 2008 Microchip Technology Inc.
FIGURE 27-16: EXAMPLE SPI SLAVE MODE TIMING (CKE = 1)
TABLE 27-22: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1)
Param
No. Symbol Characteristic Min Max Units Conditions
70 T
SSL2SCH,
T
SSL2SCL
SSx to SCKx or SCKx Input 3 TCY —ns
70A T
SSL2WB SSx to write to SSPxBUF 3 TCY —ns
71 T
SCH SCKx Input High Time Continuous 1.25 TCY + 30 ns
71A Single byte 40 ns (Note 1)
72 TSCL SCKx Input Low Time Continuous 1.25 TCY + 30 ns
72A Single byte 40 ns (Note 1)
73A TB2BLast Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40 ns (Note 2)
74 TSCH2DIL,
T
SCL2DIL
Hold Time of SDIx Data Input to SCKx Edge 100 ns
75 TDOR SDOx Data Output Rise Time 25 ns
76 TDOF SDOx Data Output Fall Time 25 ns
77 T
SSH2DOZ SSx to SDOx Output High-Impedance 10 50 ns
80 T
SCH2DOV,
T
SCL2DOV
SDOx Data Output Valid after SCKx Edge 50 ns
82 T
SSL2DOV SDOx Data Output Valid after SSx Edge 50 ns
83 T
SCH2SSH,
T
SCL2SSH
SSx after SCKx Edge 1.5 TCY + 40 ns
Note 1: Requires the use of Parameter #73A.
2: Only if Parameter #71A and #72A are used.
SSx
SCKx
(CKP = 0)
SCKx
(CKP = 1)
SDOx
70
71 72
82
SDIx
74
75, 76
MSb bit 6 - - - - - - 1 LSb
77
bit 6 - - - - 1 LSb In
80
83
Note: Refer to Figure 27-3 for load conditions.
MSb In
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 415
PIC18F87J11 FAMILY
FIGURE 27-17: I2C™ BUS START/STOP BITS TIMING
TABLE 27-23: I2C™ BUS START/STOP BITS REQUIREMENTS (SLAVE MODE)
FIGURE 27-18: I2C™ BUS DATA TIMING
Note: Refer to Figure 27-3 for load conditions.
91
92
93
SCLx
SDAx
Start
Condition
Stop
Condition
90
Param.
No. Symbol Characteristic Min Max Units Conditions
90 TSU:STA Start Condition 100 kHz mode 4700 ns Only relevant for Repeated
Start condition
Setup Time 400 kHz mode 600
91 THD:STA Start Condition 100 kHz mode 4000 ns After this period, the first
clock pulse is generated
Hold Time 400 kHz mode 600
92 TSU:STO Stop Condition 100 kHz mode 4700 ns
Setup Time 400 kHz mode 600
93 THD:STO Stop Condition 100 kHz mode 4000 ns
Hold Time 400 kHz mode 600
Note: Refer to Figure 27-3 for load conditions.
90
91 92
100
101
103
106 107
109 109
110
102
SCLx
SDAx
In
SDAx
Out
PIC18F87J11 FAMILY
DS39778C-page 416 Preliminary © 2008 Microchip Technology Inc.
TABLE 27-24: I2C™ BUS DATA REQUIREMENTS (SLAVE MODE)
Param.
No. Symbol Characteristic Min Max Units Conditions
100 THIGH Clock High Time 100 kHz mode 4.0 μs
400 kHz mode 0.6 μs
MSSP modules 1.5 TCY
101 TLOW Clock Low Time 100 kHz mode 4.7 μs
400 kHz mode 1.3 μs
MSSP modules 1.5 TCY
102 TRSDAx and SCLx Rise Time 100 kHz mode 1000 ns
400 kHz mode 20 + 0.1 CB300 ns CB is specified to be from
10 to 400 pF
103 TFSDAx and SCLx Fall Time 100 kHz mode 300 ns
400 kHz mode 20 + 0.1 CB300 ns CB is specified to be from
10 to 400 pF
90 TSU:STA Start Condition Setup Time 100 kHz mode 4.7 μs Only relevant for Repeated
Start condition
400 kHz mode 0.6 μs
91 THD:STA Start Condition Hold Time 100 kHz mode 4.0 μs After this period, the first clock
pulse is generated
400 kHz mode 0.6 μs
106 THD:DAT Data Input Hold Time 100 kHz mode 0 ns
400 kHz mode 0 0.9 μs
107 TSU:DAT Data Input Setup Time 100 kHz mode 250 ns (Note 2)
400 kHz mode 100 ns
92 TSU:STO Stop Condition Setup Time 100 kHz mode 4.7 μs
400 kHz mode 0.6 μs
109 TAA Output Valid from Clock 100 kHz mode 3500 ns (Note 1)
400 kHz mode ns
110 TBUF Bus Free Time 100 kHz mode 4.7 μs Time the bus must be free
before a new transmission can
start
400 kHz mode 1.3 μs
D102 CBBus Capacitive Loading 400 pF
Note 1: As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns)
of the falling edge of SCLx to avoid unintended generation of Start or Stop conditions.
2: A Fast mode I2C™ bus device can be used in a Standard mode I2C bus system, but the requirement, TSU:DAT 250 ns,
must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCLx signal.
If such a device does stretch the LOW period of the SCLx signal, it must output the next data bit to the SDAx line,
TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I2C bus specification), before the SCLx
line is released.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 417
PIC18F87J11 FAMILY
FIGURE 27-19: MSSP I2C™ BUS START/STOP BITS TIMING WAVEFORMS
TABLE 27-25: MSSP I2C™ BUS START/STOP BITS REQUIREMENTS
FIGURE 27-20: MSSP I2C™ BUS DATA TIMING
Note: Refer to Figure 27-3 for load conditions.
91 93
SCLx
SDAx
Start
Condition
Stop
Condition
90 92
Param.
No. Symbol Characteristic Min Max Units Conditions
90 TSU:STA Start Condition 100 kHz mode 2(TOSC)(BRG + 1) ns Only relevant for
Repeated Start
condition
Setup Time 400 kHz mode 2(TOSC)(BRG + 1)
1 MHz mode(1) 2(TOSC)(BRG + 1)
91 THD:STA Start Condition 100 kHz mode 2(TOSC)(BRG + 1) ns After this period, the
first clock pulse is
generated
Hold Time 400 kHz mode 2(TOSC)(BRG + 1)
1 MHz mode(1) 2(TOSC)(BRG + 1)
92 TSU:STO Stop Condition 100 kHz mode 2(TOSC)(BRG + 1) ns
Setup Time 400 kHz mode 2(TOSC)(BRG + 1)
1 MHz mode(1) 2(TOSC)(BRG + 1)
93 THD:STO Stop Condition 100 kHz mode 2(TOSC)(BRG + 1) ns
Hold Time 400 kHz mode 2(TOSC)(BRG + 1)
1 MHz mode(1) 2(TOSC)(BRG + 1)
Note 1: Maximum pin capacitance = 10 pF for all I2C™ pins.
Note: Refer to Figure 27-3 for load conditions.
90 91 92
100
101
103
106 107
109 109 110
102
SCLx
SDAx
In
SDAx
Out
PIC18F87J11 FAMILY
DS39778C-page 418 Preliminary © 2008 Microchip Technology Inc.
TABLE 27-26: MSSP I2C™ BUS DATA REQUIREMENTS
Param.
No. Symbol Characteristic Min Max Units Conditions
100 THIGH Clock High Time 100 kHz mode 2(TOSC)(BRG + 1) ms
400 kHz mode 2(TOSC)(BRG + 1) ms
1 MHz mode(1) 2(TOSC)(BRG + 1) ms
101 TLOW Clock Low Time 100 kHz mode 2(TOSC)(BRG + 1) ms
400 kHz mode 2(TOSC)(BRG + 1) ms
1 MHz mode(1) 2(TOSC)(BRG + 1) ms
102 TRSDAx and SCLx
Rise Time
100 kHz mode 1000 ns CB is specified to be from
10 to 400 pF
400 kHz mode 20 + 0.1 CB300 ns
1 MHz mode(1) 300 ns
103 TFSDAx and SCLx
Fall Time
100 kHz mode 300 ns CB is specified to be from
10 to 400 pF
400 kHz mode 20 + 0.1 CB 300 ns
1 MHz mode(1) 100 ns
90 T
SU:STA Start Condition
Setup Time
100 kHz mode 2(TOSC)(BRG + 1) ms Only relevant for Repeated
Start condition
400 kHz mode 2(TOSC)(BRG + 1) ms
1 MHz mode(1) 2(TOSC)(BRG + 1) ms
91 THD:STA Start Condition
Hold Time
100 kHz mode 2(TOSC)(BRG + 1) ms After this period, the first
clock pulse is generated
400 kHz mode 2(TOSC)(BRG + 1) ms
1 MHz mode(1) 2(TOSC)(BRG + 1) ms
106 THD:DAT Data Input
Hold Time
100 kHz mode 0 ns
400 kHz mode 0 0.9 ms
1 MHz mode(1) TBD ns
107 TSU:DAT Data Input
Setup Time
100 kHz mode 250 ns (Note 2)
400 kHz mode 100 ns
1 MHz mode(1) TBD ns
92 TSU:STO Stop Condition
Setup Time
100 kHz mode 2(TOSC)(BRG + 1) ms
400 kHz mode 2(TOSC)(BRG + 1) ms
1 MHz mode(1) 2(TOSC)(BRG + 1) ms
109 TAA Output Valid
from Clock
100 kHz mode 3500 ns
400 kHz mode 1000 ns
1 MHz mode(1) ——ns
110 TBUF Bus Free Time 100 kHz mode 4.7 ms Time the bus must be free
before a new transmission
can start
400 kHz mode 1.3 ms
1 MHz mode(1) TBD ms
D102 CBBus Capacitive Loading 400 pF
Legend: TBD = To Be Determined
Note 1: Maximum pin capacitance = 10 pF for all I2C™ pins.
2: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but parameter #107 250 ns
must then be met. This will automatically be the case if the device does not stretch the LOW period of the
SCLx signal. If such a device does stretch the LOW period of the SCLx signal, it must output the next data
bit to the SDAx line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode), before
the SCLx line is released.
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 419
PIC18F87J11 FAMILY
FIGURE 27-21: EUSART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING
TABLE 27-27: EUSART SYNCHRONOUS TRANSMISSION REQUIREMENTS
FIGURE 27-22: EUSART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING
TABLE 27-28: EUSART SYNCHRONOUS RECEIVE REQUIREMENTS
121 121
120 122
TXx/CKx
RXx/DTx
pin
pin
Note: Refer to Figure 27-3 for load conditions.
Param
No. Symbol Characteristic Min Max Units Conditions
120 T
CKH2DTV SYNC XMIT (MASTER and SLAVE)
Clock High to Data Out Valid 40 ns
121 TCKRF Clock Out Rise Time and Fall Time (Master mode) 20 ns
122 TDTRF Data Out Rise Time and Fall Time 20 ns
125
126
TXx/CKx
RXx/DTx
pin
pin
Note: Refer to Figure 27-3 for load conditions.
Param.
No. Symbol Characteristic Min Max Units Conditions
125 TDTV2CKL SYNC RCV (MASTER and SLAVE)
Data Hold before CKx (DTx hold time) 10 ns
126 TCKL2DTL Data Hold after CKx (DTx hold time) 15 ns
PIC18F87J11 FAMILY
DS39778C-page 420 Preliminary © 2008 Microchip Technology Inc.
TABLE 27-29: A/D CONVERTER CHARACTERISTICS: PIC18F87J11 FAMILY (INDUSTRIAL)
FIGURE 27-23: A/D CONVERSION TIMING
Param
No. Symbol Characteristic Min Typ Max Units Conditions
A01 NRResolution 10 bit ΔVREF 3.0V
A03 EIL Integral Linearity Error <±1 LSb ΔVREF 3.0V
A04 EDL Differential Linearity Error <±1 LSb ΔVREF 3.0V
A06 EOFF Offset Error <±3 LSb ΔVREF 3.0V
A07 EGN Gain Error <±3 LSb ΔVREF 3.0V
A10 Monotonicity Guaranteed(1) —VSS VAIN VREF
A20 ΔVREF Reference Voltage Range
(VREFH – VREFL)
2.0
3
V
V
VDD < 3.0V
VDD 3.0V
A21 VREFH Reference Voltage High VSS —VREFH V
A22 VREFL Reference Voltage Low VSS – 0.3V VDD 3.0V V
A25 VAIN Analog Input Voltage VREFL —VREFH V
A30 ZAIN Recommended Impedance of
Analog Voltage Source
——2.5kΩ
A50 IREF VREF Input Current(2)
5
150
μA
μA
During VAIN acquisition.
During A/D conversion
cycle.
Note 1: The A/D conversion result never decreases with an increase in the input voltage and has no missing codes.
2: VREFH current is from RA3/AN3/VREF+ pin or VDD, whichever is selected as the VREFH source.
VREFL current is from RA2/AN2/VREF- pin or VSS, whichever is selected as the VREFL source.
131
130
132
BSF ADCON0, GO
Q4
A/D CLK
A/D DATA
ADRES
ADIF
GO
SAMPLE
OLD_DATA
SAMPLING STOPPED
DONE
NEW_DATA
(Note 2)
98 7 2 1 0
Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction
to be executed.
2: This is a minimal RC delay (typically 100 ns), which also disconnects the holding capacitor from the analog input.
. . . . . .
TCY (Note 1)
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 421
PIC18F87J11 FAMILY
TABLE 27-30: A/D CONVERSION REQUIREMENTS
Param
No. Symbol Characteristic Min Max Units Conditions
130 TAD A/D Clock Period 0.7 25.0(1) μsTOSC based, VREF 3.0V
TBD 1 μs A/D RC mode
131 TCNV Conversion Time
(not including acquisition time) (Note 2)
11 12 TAD
132 TACQ Acquisition Time (Note 3) 1.4 μs-40°C to +85°C
135 TSWC Switching Time from Convert Sample (Note 4)
TBD TDIS Discharge Time 0.2 μs
Legend: TBD = To Be Determined
Note 1: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider.
2: ADRES registers may be read on the following TCY cycle.
3: The time for the holding capacitor to acquire the “New” input voltage when the voltage changes full scale
after the conversion (VDD to VSS or VSS to VDD). The source impedance (RS) on the input channels is 50Ω.
4: On the following cycle of the device clock.
PIC18F87J11 FAMILY
DS39778C-page 422 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 423
PIC18F87J11 FAMILY
28.0 PACKAGING INFORMATION
28.1 Package Marking Information
64-Lead TQFP
XXXXXXXXXX
XXXXXXXXXX
XXXXXXXXXX
YYWWNNN
Example
18F67J11
-I/PT
0810017
80-Lead TQFP
XXXXXXXXXXXX
XXXXXXXXXXXX
YYWWNNN
Example
PIC18F87J11
-I/PT
0810017
Legend: XX...X Customer-specific information
Y Year code (last digit of calendar year)
YY Year code (last 2 digits of calendar year)
WW Week code (week of January 1 is week ‘01’)
NNN Alphanumeric traceability code
Pb-free JEDEC designator for Matte Tin (Sn)
*This package is Pb-free. The Pb-free JEDEC designator ( )
can be found on the outer packaging for this package.
Note: In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.
3
e
3
e
3
e
3
e
PIC18F87J11 FAMILY
DS39778C-page 424 Preliminary © 2008 Microchip Technology Inc.
28.2 Package Details
The following sections give the technical details of the packages.
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)RRW$QJOH   
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D
D1
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e
b
N
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c
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A1
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β
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DS39778C-page 426 Preliminary © 2008 Microchip Technology Inc.
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PIC18F87J11 FAMILY
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PIC18F87J11 FAMILY
DS39778C-page 428 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 429
PIC18F87J11 FAMILY
APPENDIX A: REVISION HISTORY
Revision A (January 2007)
Original data sheet for the PIC18F87J11 Family of
devices.
Revision B (February 2007)
Updated values in Power-Down and Supply Current
table in “DC Characteristics” section.
Revision C (January 2008)
Updated text and values in several chapters and added
land pattern diagrams for both packages.
APPENDIX B: DEVICE
DIFFERENCES
The differences between the devices listed in this data
sheet are shown in Table B-1.
TABLE B-1: DEVICE DIFFERENCES BETWEEN PIC18F87J11 FAMILY MEMBERS
Features PIC18F66J11 PIC18F66J16 PIC18F67J11 PIC18F86J11 PIC18F86J16 PIC18F87J11
Program memory 64K 96K 128K 64K 96K 128K
Program Memory
(Instructions)
32764 49148 65532 32764 49148 65532
I/O Ports Ports A, B, C, D, E, F, G Ports A, B, C, D, E, F, G, H, J
EMB No Yes
10-Bit ADC module 11 Input Channels 15 Input Channels
Packages 64-Pin TQFP 80-Pin TQFP
PIC18F87J11 FAMILY
DS39778C-page 430 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 431
PIC18F87J11 FAMILY
THE MICROCHIP WEB SITE
Microchip provides online support via our WWW site at
www.microchip.com. This web site is used as a means
to make files and information easily available to
customers. Accessible by using your favorite Internet
browser, the web site contains the following
information:
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application notes and sample programs, design
resources, user’s guides and hardware support
documents, latest software releases and archived
software
General Technical Support – Frequently Asked
Questions (FAQ), technical support requests,
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Microchip sales offices, distributors and factory
representatives
CUSTOMER CHANGE NOTIFICATION
SERVICE
Microchip’s customer notification service helps keep
customers current on Microchip products. Subscribers
will receive e-mail notification whenever there are
changes, updates, revisions or errata related to a
specified product family or development tool of interest.
To register, access the Microchip web site at
www.microchip.com, click on Customer Change
Notification and follow the registration instructions.
CUSTOMER SUPPORT
Users of Microchip products can receive assistance
through several channels:
Distributor or Representative
Local Sales Office
Field Application Engineer (FAE)
Technical Support
Development Systems Information Line
Customers should contact their distributor,
representative or field application engineer (FAE) for
support. Local sales offices are also available to help
customers. A listing of sales offices and locations is
included in the back of this document.
Technical support is available through the web site
at: http://support.microchip.com
PIC18F87J11 FAMILY
DS39778C-page 432 Preliminary © 2008 Microchip Technology Inc.
READER RESPONSE
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip prod-
uct. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation
can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150.
Please list the following information, and use this outline to provide us with your comments about this document.
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Questions:
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DS39778CPIC18F87J11 Family
1. What are the best features of this document?
2. How does this document meet your hardware and software development needs?
3. Do you find the organization of this document easy to follow? If not, why?
4. What additions to the document do you think would enhance the structure and subject?
5. What deletions from the document could be made without affecting the overall usefulness?
6. Is there any incorrect or misleading information (what and where)?
7. How would you improve this document?
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 433
PIC18F87J11 FAMILY
INDEX
A
A/D ................................................................................... 291
A/D Converter Interrupt, Configuring ....................... 295
Acquisition Requirements ........................................ 296
ADCAL Bit ................................................................ 299
ADRESH Register .................................................... 294
Analog Port Pins, Configuring .................................. 297
Associated Registers ............................................... 300
Automatic Acquisition Time ...................................... 297
Calibration ................................................................ 299
Configuring the Module ............................................ 295
Conversion Clock (TAD) ........................................... 297
Conversion Requirements ....................................... 421
Conversion Status (GO/DONE Bit) .......................... 294
Conversions ............................................................. 298
Converter Characteristics ........................................ 420
Operation in Power-Managed Modes ...................... 299
Special Event Trigger (ECCP) ......................... 207, 298
Use of the ECCP2 Trigger ....................................... 298
Absolute Maximum Ratings ............................................. 383
AC (Timing) Characteristics ............................................. 398
Load Conditions for Device Timing
Specifications ................................................... 399
Parameter Symbology ............................................. 398
Temperature and Voltage Specifications ................. 399
Timing Conditions .................................................... 399
ACKSTAT ........................................................................ 257
ACKSTAT Status Flag ..................................................... 257
ADCAL Bit ........................................................................ 299
ADCON0 Register
GO/DONE Bit ........................................................... 294
ADDFSR .......................................................................... 372
ADDLW ............................................................................ 335
ADDULNK ........................................................................ 372
ADDWF ............................................................................ 335
ADDWFC ......................................................................... 336
ADRESL Register ............................................................ 294
Analog-to-Digital Converter. See A/D.
ANDLW ............................................................................ 336
ANDWF ............................................................................ 337
Assembler
MPASM Assembler .................................................. 380
Auto-Wake-up on Sync Break Character ......................... 282
B
Baud Rate Generator ....................................................... 253
BC .................................................................................... 337
BCF .................................................................................. 338
BF .................................................................................... 257
BF Status Flag ................................................................. 257
Block Diagrams
16-Bit Byte Select Mode .......................................... 103
16-Bit Byte Write Mode ............................................ 101
16-Bit Word Write Mode ........................................... 102
8-Bit Multiplexed Address and Data Application ...... 173
8-Bit Multiplexed Mode Example ............................. 105
A/D ........................................................................... 294
Analog Input Model .................................................. 295
Baud Rate Generator ............................................... 253
Capture Mode Operation ......................................... 197
Comparator .............................................................. 301
Comparator Analog Input Model .............................. 304
Comparator I/O Configurations ................................ 306
Comparator Voltage Reference ............................... 309
Comparator Voltage Reference Output
Buffer Example ................................................ 311
Compare Mode Operation ....................................... 198
Connections for On-Chip Voltage Regulator ........... 323
Demultiplexed Addressing Mode ............................. 165
Device Clock .............................................................. 31
Enhanced PWM ....................................................... 208
EUSART Receive .................................................... 281
EUSART Transmit ................................................... 279
External Power-on Reset Circuit
(Slow VDD Power-up) ........................................ 51
Fail-Safe Clock Monitor ........................................... 325
Fully Multiplexed Addressing Mode ......................... 165
Generic I/O Port Operation ...................................... 127
Interrupt Logic .......................................................... 112
LCD Control ............................................................. 174
Legacy Parallel Slave Port ...................................... 159
MSSP (SPI Mode) ................................................... 221
MSSPx (I2C Master Mode) ...................................... 251
MSSPx (I2C Mode) .................................................. 231
Multiplexed Addressing Application ......................... 173
On-Chip Reset Circuit ................................................ 49
Parallel EEPROM (Up to 15-Bit Address,
16-Bit Data) ..................................................... 174
Parallel EEPROM (Up to 15-Bit Address,
8-Bit Data) ....................................................... 174
Parallel Master/Slave Connection
Addressed Buffer ............................................. 162
Parallel Master/Slave Connection Buffered ............. 161
Partially Multiplexed Addressing Application ........... 173
Partially Multiplexed Addressing Mode .................... 165
PIC18F6XJ1X (64-Pin) .............................................. 10
PIC18F8XJ1X (80-Pin) .............................................. 11
PLL ............................................................................ 36
PMP Module ............................................................ 151
PWM Operation (Simplified) .................................... 200
Reads From Flash Program Memory ........................ 91
Table Read Operation ............................................... 87
Table Write Operation ............................................... 88
Table Writes to Flash Program Memory .................... 93
Timer0 in 16-Bit Mode ............................................. 178
Timer0 in 8-Bit Mode ............................................... 178
Timer1 ..................................................................... 182
Timer1 (16-Bit Read/Write Mode) ............................ 182
Timer2 ..................................................................... 188
Timer3 ..................................................................... 190
Timer3 (16-Bit Read/Write Mode) ............................ 190
Timer4 ..................................................................... 194
Watchdog Timer ...................................................... 321
BN .................................................................................... 338
BNC ................................................................................. 339
BNN ................................................................................. 339
BNOV .............................................................................. 340
BNZ ................................................................................. 340
BOR. See Brown-out Reset.
BOV ................................................................................. 343
BRA ................................................................................. 341
Break Character (12-Bit) Transmit and Receive .............. 284
BRG. See Baud Rate Generator.
Brown-out Reset (BOR) ..................................................... 51
and On-Chip Voltage Regulator .............................. 324
Detecting ................................................................... 51
Disabling in Sleep Mode ............................................ 51
PIC18F87J11 FAMILY
DS39778C-page 434 Preliminary © 2008 Microchip Technology Inc.
BSF .................................................................................. 341
BTFSC ............................................................................. 342
BTFSS .............................................................................. 342
BTG ..................................................................................343
BZ .....................................................................................344
C
C Compilers
MPLAB C18 .............................................................380
MPLAB C30 .............................................................380
Calibration (A/D Converter) .............................................. 299
CALL ................................................................................344
CALLW ............................................................................. 373
Capture (CCP Module) ..................................................... 197
Associated Registers ............................................... 199
CCP Pin Configuration ............................................. 197
CCPRxH:CCPRxL Registers ................................... 197
Prescaler ..................................................................197
Software Interrupt .................................................... 197
Timer1/Timer3 Mode Selection ................................ 197
Capture (ECCP Module) .................................................. 207
Capture/Compare/PWM (CCP) ........................................ 195
Capture Mode. See Capture.
CCP Mode and Timer Resources ............................ 196
CCPRxH Register .................................................... 196
CCPRxL Register .....................................................196
Compare Mode. See Compare.
Module Configuration ............................................... 196
Timer Interconnect Configurations ........................... 196
Clock Sources .................................................................... 33
Default System Clock on Reset ................................. 34
Selection Using OSCCON Register ........................... 34
CLRF ................................................................................ 345
CLRWDT ..........................................................................345
Code Examples
16 x 16 Signed Multiply Routine .............................. 110
16 x 16 Unsigned Multiply Routine .......................... 110
8 x 8 Signed Multiply Routine .................................. 109
8 x 8 Unsigned Multiply Routine .............................. 109
A/D Calibration Routine ...........................................299
Changing Between Capture Prescalers ................... 197
Computed GOTO Using an Offset Value ...................67
Erasing a Flash Program Memory Row ..................... 92
Fast Register Stack .................................................... 67
How to Clear RAM (Bank 1) Using
Indirect Addressing ............................................ 81
Implementing a Real-Time Clock Using
a Timer1 Interrupt Service ...............................185
Initializing PORTA .................................................... 130
Initializing PORTB .................................................... 132
Initializing PORTC .................................................... 134
Initializing PORTD .................................................... 136
Initializing PORTE .................................................... 139
Initializing PORTF ....................................................142
Initializing PORTG ...................................................144
Initializing PORTH .................................................... 146
Initializing PORTJ .................................................... 149
Loading the SSP1BUF (SSP1SR) Register ............. 224
Reading a Flash Program Memory Word .................. 91
Saving STATUS, WREG and BSR
Registers in RAM ............................................. 126
Single-Word Write to Flash Program Memory ........... 95
Writing to Flash Program Memory ............................. 94
Code Protection ............................................................... 313
COMF ............................................................................... 346
Comparator ...................................................................... 301
Analog Input Connection Considerations ................ 304
Associated Registers ............................................... 308
Configuration ........................................................... 305
Control ..................................................................... 305
Effects of a Reset .................................................... 308
Enable, Input Selection ............................................ 305
Enable, Output Selection ......................................... 305
Interrupts ................................................................. 307
Operation ................................................................. 304
Operation During Sleep ........................................... 308
Reference
Response Time ............................................... 304
Single Comparator ................................................... 304
Comparator Specifications ............................................... 397
Comparator Voltage Reference ....................................... 309
Accuracy and Error .................................................. 311
Associated Registers ............................................... 311
Configuring .............................................................. 310
Connection Considerations ...................................... 311
Effects of a Reset .................................................... 311
Operation During Sleep ........................................... 311
Compare (CCP Module) .................................................. 198
Associated Registers ............................................... 199
CCPRx Register ...................................................... 198
Pin Configuration ..................................................... 198
Software Interrupt .................................................... 198
Timer1/Timer3 Mode Selection ................................ 198
Compare (ECCP Module) ................................................ 207
Special Event Trigger ...................................... 207, 298
Compare (ECCPx Modules)
Special Event Trigger .............................................. 191
Computed GOTO ............................................................... 67
Configuration Bits ............................................................ 313
Configuration Mismatch Reset (CM) .................................. 51
Configuration Register Protection .................................... 327
Core Features
Easy Migration ............................................................. 8
Expanded Memory ....................................................... 7
Extended Instruction Set ............................................. 7
External Memory Bus .................................................. 7
nanoWatt Technology .................................................. 7
Oscillator Options and Features .................................. 7
CPFSEQ .......................................................................... 346
CPFSGT .......................................................................... 347
CPFSLT ........................................................................... 347
Crystal Oscillator/Ceramic Resonator ................................ 35
Customer Change Notification Service ............................ 431
Customer Notification Service ......................................... 431
Customer Support ............................................................ 431
D
Data Addressing Modes .................................................... 81
Comparing Addressing Modes with the
Extended Instruction Set Enabled ..................... 85
Direct ......................................................................... 81
Indexed Literal Offset ................................................ 84
BSR ................................................................... 86
Instructions Affected .......................................... 84
Mapping Access Bank ....................................... 86
Indirect ....................................................................... 81
Inherent and Literal .................................................... 81
Data Memory ..................................................................... 70
Access Bank .............................................................. 72
Bank Select Register (BSR) ...................................... 70
Extended Instruction Set ........................................... 84
General Purpose Registers ....................................... 72
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 435
PIC18F87J11 FAMILY
Memory Map .............................................................. 71
Memory Maps
Special Function Registers ................................ 73
Special Function Registers ........................................ 73
Context Defined SFRs ....................................... 74
Shared Address ................................................. 74
DAW ................................................................................. 348
DC Characteristics ........................................................... 394
Power-Down and Supply Current ............................ 386
Supply Voltage ......................................................... 385
DCFSNZ .......................................................................... 349
DECF ............................................................................... 348
DECFSZ ........................................................................... 349
Default System Clock ......................................................... 34
Development Support ...................................................... 379
Device Differences ........................................................... 429
Device Overview .................................................................. 7
Details on Individual Family Members ......................... 8
Features (64-Pin Devices) ........................................... 9
Features (80-Pin Devices) ........................................... 9
Direct Addressing ............................................................... 82
E
ECCP
Associated Registers ............................................... 219
Capture and Compare Modes .................................. 207
Enhanced PWM Mode ............................................. 208
Standard PWM Mode ............................................... 207
Effect on Standard PIC Instructions ................................. 376
Effects of Power-Managed Modes on
Various Clock Sources ............................................... 40
Electrical Characteristics .................................................. 383
Enhanced Capture/Compare/PWM (ECCP) .................... 203
Capture Mode. See Capture (ECCP Module).
ECCP1/ECCP3 Outputs and
Program Memory Mode ................................... 204
ECCP2 Outputs and Program Memory Modes ........ 204
Outputs and Configuration ....................................... 204
Pin Configurations for ECCP1 ................................. 205
Pin Configurations for ECCP2 ................................. 206
Pin Configurations for ECCP3 ................................. 206
PWM Mode. See PWM (ECCP Module).
Timer Resources ...................................................... 205
Use of CCP4/CCP5 with ECCP1/ECCP3 ................ 205
Enhanced Universal Synchronous Asynchronous
Receiver Transmitter (EUSART). See EUSART.
ENVREG pin .................................................................... 323
Equations
A/D Acquisition Time ................................................ 296
A/D Minimum Charging Time ................................... 296
Calculating the Minimum Required
Acquisition Time .............................................. 296
Errata ................................................................................... 5
EUSART
Asynchronous Mode ................................................ 279
12-Bit Break Transmit and Receive ................. 284
Associated Registers, Receive ........................ 282
Associated Registers, Transmit ....................... 280
Auto-Wake-up on Sync Break ......................... 282
Receiver ........................................................... 281
Setting Up 9-Bit Mode with
Address Detect ........................................ 281
Transmitter ....................................................... 279
Baud Rate Generator
Operation in Power-Managed Mode ................ 273
Baud Rate Generator (BRG) ................................... 273
Associated Registers ....................................... 274
Auto-Baud Rate Detect .................................... 277
Baud Rate Error, Calculating ........................... 274
Baud Rates, Asynchronous Modes ................. 275
High Baud Rate Select (BRGH Bit) ................. 273
Sampling ......................................................... 273
Synchronous Master Mode ...................................... 285
Associated Registers, Receive ........................ 288
Associated Registers, Transmit ....................... 286
Reception ........................................................ 287
Transmission ................................................... 285
Synchronous Slave Mode ........................................ 288
Associated Registers, Receive ........................ 290
Associated Registers, Transmit ....................... 289
Reception ........................................................ 289
Transmission ................................................... 288
Extended Instruction Set
ADDFSR .................................................................. 372
ADDULNK ............................................................... 372
CALLW .................................................................... 373
MOVSF .................................................................... 373
MOVSS .................................................................... 374
PUSHL ..................................................................... 374
SUBFSR .................................................................. 375
SUBULNK ................................................................ 375
External Memory Bus ........................................................ 97
16-Bit Byte Select Mode .......................................... 103
16-Bit Byte Write Mode ............................................ 101
16-Bit Data Width Modes ......................................... 100
16-Bit Mode Timing ................................................. 104
16-Bit Word Write Mode .......................................... 102
8-Bit Data Width Mode ............................................ 105
8-Bit Mode Timing ................................................... 106
Address and Data Line Usage (table) ....................... 99
Address and Data Width ............................................ 99
Address Shifting ........................................................ 99
Control ....................................................................... 98
I/O Port Functions ...................................................... 97
Operation in Power-Managed Modes ...................... 107
Program Memory Modes ......................................... 100
Extended Microcontroller ................................. 100
Microcontroller ................................................. 100
Wait States .............................................................. 100
Weak Pull-ups on Port Pins ..................................... 100
External Oscillator Modes
Clock Input (EC Modes) ............................................ 36
HS .............................................................................. 35
F
Fail-Safe Clock Monitor ........................................... 313, 325
Exiting ...................................................................... 326
Interrupts in Power-Managed Modes ...................... 326
POR or Wake-up From Sleep .................................. 326
WDT During Oscillator Failure ................................. 325
Fast Register Stack ........................................................... 67
Firmware Instructions ...................................................... 329
Flash Configuration Words .............................................. 313
Flash Program Memory ..................................................... 87
Associated Registers ................................................. 96
Control Registers ....................................................... 88
EECON1 and EECON2 ..................................... 88
TABLAT (Table Latch) Register ........................ 90
TBLPTR (Table Pointer) Register ...................... 90
Erase Sequence ........................................................ 92
Erasing ...................................................................... 92
PIC18F87J11 FAMILY
DS39778C-page 436 Preliminary © 2008 Microchip Technology Inc.
Operation During Code-Protect ................................. 96
Reading ......................................................................91
Table Pointer
Boundaries Based on Operation ........................ 90
Table Pointer Boundaries .......................................... 90
Table Reads and Table Writes .................................. 87
Write Sequence ......................................................... 93
Write Sequence (Word Programming) ....................... 95
Writing ........................................................................93
Unexpected Termination ....................................96
Write Verify ........................................................ 96
FSCM. See Fail-Safe Clock Monitor.
G
GOTO ...............................................................................350
H
Hardware Multiplier .......................................................... 109
8 x 8 Multiplication Algorithms ................................. 109
Operation ................................................................. 109
Performance Comparison (table) .............................109
I
I/O Ports ........................................................................... 127
Input Pull-up Configuration ...................................... 128
Open-Drain Outputs ................................................. 128
Pin Capabilities ........................................................ 127
I2C Mode (MSSP)
Acknowledge Sequence Timing ............................... 260
Associated Registers ............................................... 268
Baud Rate Generator ............................................... 253
Bus Collision
During a Repeated Start Condition .................. 265
During a Stop Condition ................................... 267
Clock Arbitration ....................................................... 254
Clock Stretching ....................................................... 246
10-Bit Slave Receive Mode (SEN = 1) ............. 246
10-Bit Slave Transmit Mode ............................. 246
7-Bit Slave Receive Mode (SEN = 1) ............... 246
7-Bit Slave Transmit Mode ............................... 246
Clock Synchronization and the CKP bit ................... 247
Effects of a Reset ..................................................... 261
General Call Address Support ................................. 250
I2C Clock Rate w/BRG ............................................. 253
Master Mode ............................................................ 251
Operation ......................................................... 252
Reception ......................................................... 257
Repeated Start Condition Timing ..................... 256
Start Condition Timing ..................................... 255
Transmission ....................................................257
Multi-Master Communication, Bus Collision
and Arbitration .................................................. 261
Multi-Master Mode ...................................................261
Operation ................................................................. 236
Read/Write Bit Information (R/W Bit) ............... 236, 239
Registers ..................................................................231
Serial Clock (RC3/SCKx/SCLx) ...............................239
Slave Mode ..............................................................236
Address Masking Modes
5-Bit ......................................................... 237
7-Bit ......................................................... 238
Addressing ....................................................... 236
Reception ......................................................... 239
Transmission ....................................................239
Sleep Operation ....................................................... 261
Stop Condition Timing ..............................................260
INCF ................................................................................ 350
INCFSZ ............................................................................ 351
In-Circuit Debugger .......................................................... 327
In-Circuit Serial Programming (ICSP) ...................... 313, 327
Indexed Literal Offset Addressing
and Standard PIC18 Instructions ............................. 376
Indexed Literal Offset Mode ............................................. 376
Indirect Addressing ............................................................ 82
INFSNZ ............................................................................ 351
Initialization Conditions for all Registers ...................... 55–60
Instruction Cycle ................................................................ 68
Clocking Scheme ....................................................... 68
Flow/Pipelining ........................................................... 68
Instruction Set .................................................................. 329
ADDLW .................................................................... 335
ADDWF .................................................................... 335
ADDWF (Indexed Literal Offset Mode) .................... 377
ADDWFC ................................................................. 336
ANDLW .................................................................... 336
ANDWF .................................................................... 337
BC ............................................................................ 337
BCF ......................................................................... 338
BN ............................................................................ 338
BNC ......................................................................... 339
BNN ......................................................................... 339
BNOV ...................................................................... 340
BNZ ......................................................................... 340
BOV ......................................................................... 343
BRA ......................................................................... 341
BSF .......................................................................... 341
BSF (Indexed Literal Offset Mode) .......................... 377
BTFSC ..................................................................... 342
BTFSS ..................................................................... 342
BTG ......................................................................... 343
BZ ............................................................................ 344
CALL ........................................................................ 344
CLRF ....................................................................... 345
CLRWDT ................................................................. 345
COMF ...................................................................... 346
CPFSEQ .................................................................. 346
CPFSGT .................................................................. 347
CPFSLT ................................................................... 347
DAW ........................................................................ 348
DCFSNZ .................................................................. 349
DECF ....................................................................... 348
DECFSZ .................................................................. 349
Extended Instructions .............................................. 371
Considerations when Enabling ........................ 376
Syntax .............................................................. 371
Use with MPLAB IDE Tools ............................. 378
General Format ........................................................ 331
GOTO ...................................................................... 350
INCF ........................................................................ 350
INCFSZ .................................................................... 351
INFSNZ .................................................................... 351
IORLW ..................................................................... 352
IORWF ..................................................................... 352
LFSR ....................................................................... 353
MOVF ...................................................................... 353
MOVFF .................................................................... 354
MOVLB .................................................................... 354
MOVLW ................................................................... 355
MOVWF ................................................................... 355
MULLW .................................................................... 356
MULWF .................................................................... 356
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 437
PIC18F87J11 FAMILY
NEGF ....................................................................... 357
NOP ......................................................................... 357
Opcode Field Descriptions ....................................... 330
POP ......................................................................... 358
PUSH ....................................................................... 358
RCALL ..................................................................... 359
RESET ..................................................................... 359
RETFIE .................................................................... 360
RETLW .................................................................... 360
RETURN .................................................................. 361
RLCF ........................................................................ 361
RLNCF ..................................................................... 362
RRCF ....................................................................... 362
RRNCF .................................................................... 363
SETF ........................................................................ 363
SETF (Indexed Literal Offset Mode) ........................ 377
SLEEP ..................................................................... 364
Standard Instructions ............................................... 329
SUBFWB .................................................................. 364
SUBLW .................................................................... 365
SUBWF .................................................................... 365
SUBWFB .................................................................. 366
SWAPF .................................................................... 366
TBLRD ..................................................................... 367
TBLWT ..................................................................... 368
TSTFSZ ................................................................... 369
XORLW .................................................................... 369
XORWF .................................................................... 370
INTCON Register
RBIF Bit .................................................................... 132
INTCON Registers ........................................................... 113
Inter-Integrated Circuit. See I2C.
Internal Oscillator Block ..................................................... 37
Adjustment ................................................................. 38
INTIO Modes .............................................................. 37
INTOSC Frequency Drift ............................................ 38
INTOSC Output Frequency ........................................ 38
INTPLL Modes ........................................................... 37
Internal RC Block
Use with WDT .......................................................... 321
Internal Voltage Reference Specifications ....................... 397
Internet Address ............................................................... 431
Interrupt Sources ............................................................. 313
A/D Conversion Complete ....................................... 295
Capture Complete (CCP) ......................................... 197
Compare Complete (CCP) ....................................... 198
Interrupt-on-Change (RB7:RB4) .............................. 132
TMR0 Overflow ........................................................ 179
TMR2 to PR2 Match (PWM) .................................... 208
TMR3 Overflow ................................................ 189, 191
TMR4 to PR4 Match ................................................ 194
TMR4 to PR4 Match (PWM) .................................... 193
Interrupts .......................................................................... 111
During, Context Saving ............................................ 126
INTx Pin ................................................................... 126
PORTB, Interrupt-on-Change .................................. 126
TMR0 ....................................................................... 126
Interrupts, Flag Bits
Interrupt-on-Change (RB7:RB4)
Flag (RBIF Bit) ................................................. 132
INTOSC, INTRC. See Internal Oscillator Block.
IORLW ............................................................................. 352
IORWF ............................................................................. 352
IPR Registers ................................................................... 122
L
LFSR ............................................................................... 353
M
Master Clear (MCLR) ......................................................... 51
Master Synchronous Serial Port (MSSP). See MSSP.
Memory Organization ........................................................ 61
Data Memory ............................................................. 70
Program Memory ....................................................... 61
Memory Programming Requirements .............................. 396
Microchip Internet Web Site ............................................. 431
MOVF .............................................................................. 353
MOVFF ............................................................................ 354
MOVLB ............................................................................ 354
MOVLW ........................................................................... 355
MOVSF ............................................................................ 373
MOVSS ............................................................................ 374
MOVWF ........................................................................... 355
MPLAB ASM30 Assembler, Linker, Librarian .................. 380
MPLAB ICD 2 In-Circuit Debugger .................................. 381
MPLAB ICE 2000 High-Performance Universal
In-Circuit Emulator ................................................... 381
MPLAB Integrated Development
Environment Software ............................................. 379
MPLAB PM3 Device Programmer ................................... 381
MPLAB REAL ICE In-Circuit Emulator System ............... 381
MPLINK Object Linker/MPLIB Object Librarian ............... 380
MSSP
ACK Pulse ....................................................... 236, 239
I2C Mode. See I2C Mode.
Module Overview ..................................................... 221
SPI Master/Slave Connection .................................. 225
MULLW ............................................................................ 356
MULWF ............................................................................ 356
N
NEGF ............................................................................... 357
NOP ................................................................................. 357
O
Open-Drain Outputs ......................................................... 128
Oscillator Configuration ..................................................... 31
EC .............................................................................. 31
ECPLL ....................................................................... 31
HS .............................................................................. 31
HSPLL ....................................................................... 31
Internal Oscillator Block ............................................. 37
INTIO1 ....................................................................... 31
INTIO2 ....................................................................... 31
INTPLL1 .................................................................... 31
INTPLL2 .................................................................... 31
Oscillator Selection .......................................................... 313
Oscillator Start-up Timer (OST) ......................................... 40
Oscillator Switching ........................................................... 33
Oscillator Transitions ......................................................... 34
Oscillator, Timer1 ..................................................... 181, 191
Oscillator, Timer3 ............................................................. 189
P
Packaging ........................................................................ 423
Details ...................................................................... 424
Marking .................................................................... 423
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DS39778C-page 438 Preliminary © 2008 Microchip Technology Inc.
Parallel Master Port (PMP) ..............................................151
Application Examples ............................................... 173
Associated Registers ............................................... 175
Control Registers .....................................................152
Data Registers ......................................................... 158
Master Port Modes ...................................................164
Slave Port Modes ..................................................... 159
PICSTART Plus Development Programmer .................... 382
PIE Registers ...................................................................119
Pin Functions
AVDD ..........................................................................29
AVDD ..........................................................................19
AVSS ..........................................................................29
AVSS ..........................................................................19
ENVREG .............................................................. 19, 29
MCLR ................................................................... 12, 20
OSC1/CLKI/RA7 .................................................. 12, 20
OSC2/CLKO/RA6 ................................................ 12, 20
RA0/AN0 .............................................................. 13, 21
RA1/AN1 .............................................................. 13, 21
RA2/AN2/VREF- .................................................... 13, 21
RA3/AN3/VREF+ ................................................... 13, 21
RA4/PMD5/T0CKI ...................................................... 21
RA4/T0CKI ................................................................. 13
RA5/AN4 .................................................................... 13
RA5/PMD4/AN4 .........................................................21
RA6 ...................................................................... 13, 21
RA7 ...................................................................... 13, 21
RB0/FLT0/INT0 .................................................... 14, 22
RB1/INT1/PMA4 .................................................. 14, 22
RB2/INT2/PMA3 .................................................. 14, 22
RB3/INT3/PMA2/ECCP2/P2A ....................................22
RB3/INT3/PMA2 ........................................................14
RB4/KBI0/PMA1 .................................................. 14, 22
RB5/KBI1/PMA0 .................................................. 14, 22
RB6/KBI2/PGC .................................................... 14, 22
RB7/KBI3/PGD .................................................... 14, 22
RC0/T1OSO/T13CKI ........................................... 15, 23
RC1/T1OSI/ECCP2/P2A ...................................... 15, 23
RC2/ECCP1/P1A ................................................. 15, 23
RC3/SCK1/SCL1 ................................................. 15, 23
RC4/SDI1/SDA1 .................................................. 15, 23
RC5/SDO1 ........................................................... 15, 23
RC6/TX1/CK1 ...................................................... 15, 23
RC7/RX1/DT1 ...................................................... 15, 23
RD0/AD0/PMD0 .........................................................24
RD0/PMD0 ................................................................. 16
RD1/AD1/PMD1 .........................................................24
RD1/PMD1 ................................................................. 16
RD2/AD2/PMD2 .........................................................24
RD2/PMD2 ................................................................. 16
RD3/AD3/PMD3 .........................................................24
RD3/PMD3 ................................................................. 16
RD4/AD4/PMD4/SDO2 .............................................. 24
RD4/PMD4/SDO2 ...................................................... 16
RD5/AD5/PMD5/SDI2/SDA2 .....................................24
RD5/PMD5/SDI2/SDA2 ............................................. 16
RD6/AD6/PMD6/SCK2/SCL2 .................................... 24
RD6/PMD6/SCK2/SCL2 ............................................ 16
RD7/AD7/PMD7/SS2 .................................................24
RD7/PMD7/SS2 ......................................................... 16
RE0/AD8/PMRD/P2D ................................................ 25
RE0/PMRD/P2D ........................................................17
RE1/AD9/PMWR/P2C ................................................25
RE1/PMWR/P2C ........................................................ 17
RE2/AD10/PMBE/P2B ............................................... 25
RE2/PMBE/P2B ......................................................... 17
RE3/AD11/PMA13/P3C/REFO .................................. 25
RE3/PMA13/P3C/REFO ............................................ 17
RE4/AD12/PMA12/P3B ............................................. 25
RE4/PMA12/P3B ....................................................... 17
RE5/AD13/PMA11/P1C ............................................. 25
RE5/PMA11/P1C ....................................................... 17
RE6/AD14/PMA10/P1B ............................................. 25
RE6/PMA10/P1B ....................................................... 17
RE7/AD15/PMA9/ECCP2/P2A .................................. 25
RE7/PMA9/ECCP2/P2A ............................................ 17
RF1/AN6/C2OUT ................................................. 18, 26
RF2/PMA5/AN7/C1OUT ...................................... 18, 26
RF3/AN8/C2INB .................................................. 18, 26
RF4/AN9/C2INA .................................................. 18, 26
RF5/AN10/C1INB/CVREF ........................................... 18
RF5/PMD2/AN10/C1INB/CVREF ................................ 26
RF6/AN11/C1INA ...................................................... 18
RF6/PMD1/AN11/C1INA ........................................... 26
RF7/PMD0/SS1 ......................................................... 26
RF7/SS1 .................................................................... 18
RG0/PMA8/ECCP3/P3A ...................................... 19, 27
RG1/PMA7/TX2/CK2 ........................................... 19, 27
RG2/PMA6/RX2/DT2 ........................................... 19, 27
RG3/PMCS1/CCP4/P3D ..................................... 19, 27
RG4/PMCS2/CCP5/P1D ..................................... 19, 27
RH0/A16 .................................................................... 28
RH1/A17 .................................................................... 28
RH2/A18/PMD7 ......................................................... 28
RH3/A19/PMD6 ......................................................... 28
RH4/PMD3/AN12/P3C/C2INC ................................... 28
RH5/PMBE/AN13/P3B/C2IND ................................... 28
RH6/PMRD/AN14/P1C/C1INC .................................. 28
RH7/PMWR/AN15/P1B ............................................. 28
RJ0/ALE .................................................................... 29
RJ1/OE ...................................................................... 29
RJ2/WRL ................................................................... 29
RJ3/WRH ................................................................... 29
RJ4/BA0 .................................................................... 29
RJ5/CE ...................................................................... 29
RJ6/LB ....................................................................... 29
RJ7/UB ...................................................................... 29
VDD ............................................................................ 29
VDD ............................................................................ 19
VDDCORE/VCAP ..................................................... 19, 29
VSS ............................................................................ 29
VSS ............................................................................ 19
Pinout I/O Descriptions
PIC18F6XJ1X (64-TQFP) .......................................... 12
PIC18F8XJ1X (80-TQFP) .......................................... 20
PIR Registers ................................................................... 116
PLL .................................................................................... 36
HSPLL and ECPLL Oscillator Modes ........................ 36
Use with INTOSC ...................................................... 36
POP ................................................................................. 358
POR. See Power-on Reset.
PORTA
Associated Registers ............................................... 132
LATA Register ......................................................... 130
PORTA Register ...................................................... 130
TRISA Register ........................................................ 130
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 439
PIC18F87J11 FAMILY
PORTB
Associated Registers ............................................... 134
LATB Register .......................................................... 132
PORTB Register ...................................................... 132
RB7:RB4 Interrupt-on-Change Flag
(RBIF Bit) ......................................................... 132
TRISB Register ........................................................ 132
PORTC
Associated Registers ............................................... 136
LATC Register ......................................................... 134
PORTC Register ...................................................... 134
RC3/SCKx/SCLx Pin ................................................ 239
TRISC Register ........................................................ 134
PORTD
Associated Registers ............................................... 138
LATD Register ......................................................... 136
PORTD Register ...................................................... 136
TRISD Register ........................................................ 136
PORTE
Associated Registers ............................................... 141
LATE Register .......................................................... 139
PORTE Register ...................................................... 139
TRISE Register ........................................................ 139
PORTF
Associated Registers ............................................... 144
LATF Register .......................................................... 142
PORTF Register ...................................................... 142
TRISF Register ........................................................ 142
PORTG
Associated Registers ............................................... 146
LATG Register ......................................................... 144
PORTG Register ...................................................... 144
TRISG Register ........................................................ 144
PORTH
Associated Registers ............................................... 148
LATH Register ......................................................... 146
PORTH Register ...................................................... 146
TRISH Register ........................................................ 146
PORTJ
Associated Registers ............................................... 150
LATJ Register .......................................................... 149
PORTJ Register ....................................................... 149
TRISJ Register ......................................................... 149
Power-Managed Modes ..................................................... 41
and EUSART Operation ........................................... 273
and SPI Operation ................................................... 229
Clock Sources ............................................................ 41
Clock Transitions and Status Indicators ..................... 42
Entering ...................................................................... 41
Exiting Idle and Sleep Modes .................................... 47
By Interrupt ........................................................ 47
By Reset ............................................................ 47
By WDT Time-out .............................................. 47
Without an Oscillator Start-up Delay .................. 47
Idle Modes ................................................................. 45
PRI_IDLE ........................................................... 46
RC_IDLE ............................................................ 47
SEC_IDLE ......................................................... 46
Multiple Sleep Commands ......................................... 42
Run Modes ................................................................. 42
PRI_RUN ........................................................... 42
RC_RUN ............................................................ 44
SEC_RUN .......................................................... 42
Selecting .................................................................... 41
Sleep Mode ............................................................... 45
OSC1 and OSC2 Pin States .............................. 40
Summary (table) ........................................................ 41
Power-on Reset (POR) ...................................................... 51
Power-up Delays ............................................................... 40
Power-up Timer (PWRT) ............................................. 40, 52
Time-out Sequence ................................................... 52
Prescaler
Timer2 ..................................................................... 209
Prescaler, Timer0 ............................................................ 179
Prescaler, Timer2 (Timer4) .............................................. 201
PRI_IDLE Mode ................................................................. 46
PRI_RUN Mode ................................................................. 42
Program Counter ............................................................... 65
PCL, PCH and PCU Registers .................................. 65
PCLATH and PCLATU Registers .............................. 65
Program Memory
ALU
Status ................................................................ 80
Extended Instruction Set ........................................... 84
Flash Configuration Words ........................................ 62
Hard Memory Vectors ................................................ 62
Instructions ................................................................ 69
Two-Word .......................................................... 69
Interrupt Vector .......................................................... 62
Look-up Tables .......................................................... 67
Memory Maps ............................................................ 61
Hard Vectors and Configuration Words ............. 62
Modes ................................................................ 64
Modes ........................................................................ 63
Extended Microcontroller ................................... 63
Extended Microcontroller (Address Shifting) ..... 64
Memory Access (table) ...................................... 64
Microcontroller ................................................... 63
Reset Vector .............................................................. 62
Program Verification and Code Protection ...................... 327
Programming, Device Instructions ................................... 329
Pull-up Configuration ....................................................... 128
Pulse-Width Modulation. See PWM (CCP Module)
and PWM (ECCP Module).
PUSH ............................................................................... 358
PUSH and POP Instructions .............................................. 66
PUSHL ............................................................................. 374
PWM (CCP Module)
Associated Registers ............................................... 202
Duty Cycle ............................................................... 200
Example Frequencies/Resolutions .......................... 201
Operation Setup ...................................................... 201
Period ...................................................................... 200
PR2/PR4 Registers ................................................. 200
TMR2 (TMR4) to PR2 (PR4) Match ........................ 200
TMR2 to PR2 Match ................................................ 208
TMR4 to PR4 Match ................................................ 193
PWM (ECCP Module) ...................................................... 208
CCPR1H:CCPR1L Registers .................................. 208
Direction Change in Full-Bridge Output Mode ......... 213
Duty Cycle ............................................................... 209
Effects of a Reset .................................................... 218
Enhanced PWM Auto-Shutdown ............................. 215
Example Frequencies/Resolutions .......................... 209
Full-Bridge Mode ..................................................... 212
Full-Bridge Output Application Example .................. 213
Half-Bridge Mode ..................................................... 211
Half-Bridge Output Mode Applications Example ..... 211
Output Configurations .............................................. 209
PIC18F87J11 FAMILY
DS39778C-page 440 Preliminary © 2008 Microchip Technology Inc.
Output Relationships (Active-High) ..........................210
Output Relationships (Active-Low) ........................... 210
Period ....................................................................... 208
Programmable Dead-Band Delay ............................ 215
Setup for PWM Operation ........................................ 218
Start-up Considerations ........................................... 217
Q
Q Clock .................................................................... 201, 209
R
RAM. See Data Memory.
RC_IDLE Mode .................................................................. 47
RC_RUN Mode ..................................................................44
RCALL ..............................................................................359
RCON Register
Bit Status During Initialization ....................................54
Reader Response ............................................................ 432
Reference Clock Output .....................................................38
Register File .......................................................................72
Register File Summary ................................................. 75–79
Registers
ADCON0 (A/D Control 0) ......................................... 291
ADCON0 (A/D Control 1) ......................................... 292
ANCON0 (A/D Port Configuration 2) ........................ 293
ANCON1 (A/D Port Configuration 1) ........................ 293
BAUDCONx (Baud Rate Control) ............................ 272
CCPxCON (Capture/Compare/PWM Control) ......... 195
CCPxCON (ECCPx Control) .................................... 203
CMSTAT (Comparator Output Status) ..................... 303
CMxCON (Comparatorx Control) .............................302
CONFIG1H (Configuration 1 High) ..........................315
CONFIG1L (Configuration 1 Low) ............................315
CONFIG2H (Configuration 2 High) ..........................317
CONFIG3H (Configuration 3 High) ..........................319
CONFIG3L (Configuration 3 Low) ...................... 63, 318
CVRCON (Comparator Voltage
Reference Control) ...........................................310
DEVID1 (Device ID 1) ..............................................320
DEVID2 (Device ID 2) ..............................................320
ECCPxAS (ECCPx Auto-Shutdown Control) ...........216
ECCPxDEL (ECCPx PWM Delay) ...........................216
EECON1 (EEPROM Control 1) .................................. 89
INTCON (Interrupt Control) ...................................... 113
INTCON2 (Interrupt Control 2) ................................. 114
INTCON3 (Interrupt Control 3) ................................. 115
IPR1 (Peripheral Interrupt Priority 1) ........................ 122
IPR2 (Peripheral Interrupt Priority 2) ........................ 123
IPR3 (Peripheral Interrupt Priority 3) ........................ 124
MEMCON (External Memory Bus Control) ................ 98
ODCON1 (Peripheral Open-Drain Control 1) ........... 129
ODCON2 (Peripheral Open-Drain Control 2) ........... 129
ODCON3 (Peripheral Open-Drain Control 3) ........... 129
OSCCON (Oscillator Control) .................................... 32
OSCTUNE (Oscillator Tuning) ................................... 33
PADCFG1 (I/O Pad Configuration Control) ............. 130
PIE1 (Peripheral Interrupt Enable 1) ........................ 119
PIE2 (Peripheral Interrupt Enable 2) ........................ 120
PIE3 (Peripheral Interrupt Enable 3) ........................ 121
PIR1 (Peripheral Interrupt Request (Flag) 1) ........... 116
PIR2 (Peripheral Interrupt Request (Flag) 2) ........... 117
PIR3 (Peripheral Interrupt Request (Flag) 3) ........... 118
PMADDRH (Parallel Port Address
High Byte, Master Mode Only) ......................... 158
PMCONH (Parallel Port Control High Byte) .............152
PMCONL (Parallel Port Control Low Byte) ..............153
PMEH (Parallel Port Enable High Byte) ................... 155
PMEL (Parallel Port Enable Low Byte) .................... 156
PMMODEH (Parallel Port Mode High Byte) ............ 154
PMMODEL (Parallel Port Mode Low Byte) .............. 155
PMSTAT (Parallel Port Status High Byte) ............... 156
PMSTAT (Parallel Port Status Low Byte) ................ 157
RCON (Reset Control) ....................................... 50, 125
RCSTAx (Receive Status and Control) .................... 271
REFOCON (Reference Oscillator Control) ................ 39
SSPCON2 (MSSPx Control 2,
I2C Master Mode) ............................................ 234
SSPCON2 (MSSPx Control 2, I2C Slave Mode) ..... 235
SSPxCON1 (MSSPx Control 1, I2C Mode) .............. 233
SSPxCON1 (MSSPx Control 1, SPI Mode) ............. 223
SSPxMSK (I2C Slave Address Mask) ...................... 235
SSPxSTAT (MSSPx Status, I2C Mode) ................... 232
SSPxSTAT (MSSPx Status, SPI Mode) .................. 222
STATUS .................................................................... 80
STKPTR (Stack Pointer) ............................................ 66
T0CON (Timer0 Control) ......................................... 177
T1CON (Timer1 Control) ......................................... 181
T2CON (Timer2 Control) ......................................... 187
T3CON (Timer3 Control) ......................................... 189
T4CON (Timer4 Control) ......................................... 193
TXSTAx (Transmit Status and Control) ................... 270
WDTCON (Watchdog Timer Control) ................ 74, 322
RESET ............................................................................. 359
Reset ................................................................................. 49
Brown-out Reset (BOR) ............................................. 49
Configuration Mismatch (CM) .................................... 49
MCLR Reset, During Power-Managed Modes .......... 49
MCLR Reset, Normal Operation ................................ 49
Power-on Reset (POR) .............................................. 49
RESET Instruction ..................................................... 49
Stack Full Reset ......................................................... 49
Stack Underflow Reset .............................................. 49
Watchdog Timer (WDT) Reset .................................. 49
Resets .............................................................................. 313
Brown-out Reset (BOR) ........................................... 313
Oscillator Start-up Timer (OST) ............................... 313
Power-on Reset (POR) ............................................ 313
Power-up Timer (PWRT) ......................................... 313
RETFIE ............................................................................ 360
RETLW ............................................................................ 360
RETURN .......................................................................... 361
Revision History ............................................................... 429
RLCF ............................................................................... 361
RLNCF ............................................................................. 362
RRCF ............................................................................... 362
RRNCF ............................................................................ 363
S
SCKx ................................................................................ 221
SDIx ................................................................................. 221
SDOx ............................................................................... 221
SEC_IDLE Mode ............................................................... 46
SEC_RUN Mode ................................................................ 42
Serial Clock, SCKx .......................................................... 221
Serial Data In (SDIx) ........................................................ 221
Serial Data Out (SDOx) ................................................... 221
Serial Peripheral Interface. See SPI Mode.
SETF ................................................................................ 363
Slave Select (SSx) ........................................................... 221
SLEEP ............................................................................. 364
Software Simulator (MPLAB SIM) ................................... 380
Special Event Trigger. See Compare (ECCP Module).
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 441
PIC18F87J11 FAMILY
Special Features of the CPU ........................................... 313
Special Function Registers
Shared Registers ....................................................... 74
SPI Mode (MSSP) ............................................................ 221
Associated Registers ............................................... 230
Bus Mode Compatibility ........................................... 229
Clock Speed, Interactions ........................................ 229
Effects of a Reset ..................................................... 229
Enabling SPI I/O ...................................................... 225
Master Mode ............................................................ 226
Master/Slave Connection ......................................... 225
Operation ................................................................. 224
Operation in Power-Managed Modes ...................... 229
Serial Clock .............................................................. 221
Serial Data In ........................................................... 221
Serial Data Out ........................................................ 221
Slave Mode .............................................................. 227
Slave Select ............................................................. 221
Slave Select Synchronization .................................. 227
SPI Clock ................................................................. 226
SSPxBUF Register .................................................. 226
SSPxSR Register ..................................................... 226
Typical Connection .................................................. 225
SSPOV ............................................................................. 257
SSPOV Status Flag ......................................................... 257
SSPxSTAT Register
R/W Bit ............................................................. 236, 239
SSx .................................................................................. 221
Stack Full/Underflow Resets .............................................. 67
SUBFSR .......................................................................... 375
SUBFWB .......................................................................... 364
SUBLW ............................................................................ 365
SUBULNK ........................................................................ 375
SUBWF ............................................................................ 365
SUBWFB .......................................................................... 366
SWAPF ............................................................................ 366
T
Table Pointer Operations (table) ........................................ 90
Table Reads/Table Writes ................................................. 67
TBLRD ............................................................................. 367
TBLWT ............................................................................. 368
Timer0 .............................................................................. 177
Associated Registers ............................................... 179
Operation ................................................................. 178
Overflow Interrupt .................................................... 179
Prescaler .................................................................. 179
Switching Assignment ...................................... 179
Prescaler Assignment (PSA Bit) .............................. 179
Prescaler Select (T0PS2:T0PS0 Bits) ..................... 179
Prescaler. See Prescaler, Timer0.
Reads and Writes in 16-Bit Mode ............................ 178
Source Edge Select (T0SE Bit) ................................ 178
Source Select (T0CS Bit) ......................................... 178
Timer1 .............................................................................. 181
16-Bit Read/Write Mode ........................................... 183
Associated Registers ............................................... 186
Considerations in Asynchronous
Counter Mode .................................................. 185
Interrupt .................................................................... 184
Operation ................................................................. 182
Oscillator .......................................................... 181, 183
Layout Considerations ..................................... 183
Oscillator, as Secondary Clock .................................. 33
Resetting, Using the ECCPx
Special Event Trigger ...................................... 184
Special Event Trigger (ECCP) ................................. 207
TMR1H Register ...................................................... 181
TMR1L Register ...................................................... 181
Use as a Clock Source ............................................ 183
Use as a Real-Time Clock ....................................... 184
Timer2 ............................................................................. 187
Associated Registers ............................................... 188
Interrupt ................................................................... 188
Operation ................................................................. 187
Output ...................................................................... 188
PR2 Register ........................................................... 208
TMR2 to PR2 Match Interrupt .................................. 208
Timer3 ............................................................................. 189
16-Bit Read/Write Mode .......................................... 191
Associated Registers ............................................... 191
Operation ................................................................. 190
Oscillator .......................................................... 189, 191
Overflow Interrupt ............................................ 189, 191
Special Event Trigger (ECCPx) ............................... 191
TMR3H Register ...................................................... 189
TMR3L Register ...................................................... 189
Timer4 ............................................................................. 193
Associated Registers ............................................... 194
Operation ................................................................. 193
Output ...................................................................... 194
Postscaler. See Postscaler, Timer4.
PR4 Register ........................................................... 193
Prescaler. See Prescaler, Timer4.
TMR4 Register ........................................................ 193
TMR4 to PR4 Match Interrupt .......................... 193, 194
Timing Diagrams
A/D Conversion ....................................................... 420
Asynchronous Reception ......................................... 282
Asynchronous Transmission ................................... 280
Asynchronous Transmission (Back to Back) ........... 280
Automatic Baud Rate Calculation ............................ 278
Auto-Wake-up Bit (WUE) During
Normal Operation ............................................ 283
Auto-Wake-up Bit (WUE) During Sleep ................... 283
Baud Rate Generator with Clock Arbitration ............ 254
BRG Overflow Sequence ........................................ 278
BRG Reset Due to SDAx Arbitration During
Start Condition ................................................. 264
Bus Collision During a Repeated
Start Condition (Case 1) .................................. 265
Bus Collision During a Repeated
Start Condition (Case 2) .................................. 266
Bus Collision During a Start
Condition (SCLx = 0) ....................................... 264
Bus Collision During a Stop
Condition (Case 1) ........................................... 267
Bus Collision During a Stop
Condition (Case 2) ........................................... 267
Bus Collision During Start
Condition (SDAx Only) .................................... 263
Bus Collision for Transmit and Acknowledge .......... 262
Capture/Compare/PWM (Including
ECCP Modules) ............................................... 410
CLKO and I/O .......................................................... 402
Clock Synchronization ............................................. 247
Clock/Instruction Cycle .............................................. 68
PIC18F87J11 FAMILY
DS39778C-page 442 Preliminary © 2008 Microchip Technology Inc.
EUSART Synchronous Receive
(Master/Slave) .................................................. 419
EUSART Synchronous Transmission
(Master/Slave) .................................................. 419
Example SPI Master Mode (CKE = 0) ..................... 411
Example SPI Master Mode (CKE = 1) ..................... 412
Example SPI Slave Mode (CKE = 0) ....................... 413
Example SPI Slave Mode (CKE = 1) ....................... 414
External Clock (All Modes Except PLL) ................... 400
External Memory Bus for Sleep (Extended
Microcontroller Mode) .............................. 104, 106
External Memory Bus for TBLRD (Extended
Microcontroller Mode) .............................. 104, 106
Fail-Safe Clock Monitor ............................................ 326
First Start Bit Timing ................................................255
Full-Bridge PWM Output .......................................... 212
Half-Bridge PWM Output ......................................... 211
I2C Acknowledge Sequence .................................... 260
I2C Bus Data ............................................................415
I2C Bus Start/Stop Bits ............................................. 415
I2C Master Mode (7 or 10-Bit Transmission) ........... 258
I2C Master Mode (7-Bit Reception) .......................... 259
I2C Slave Mode (10-Bit Reception, SEN = 0) .......... 244
I2C Slave Mode (10-Bit Reception, SEN = 0,
ADMSK = 01001) ............................................. 243
I2C Slave Mode (10-Bit Reception, SEN = 1) .......... 249
I2C Slave Mode (10-Bit Transmission) ..................... 245
I2C Slave Mode (7-Bit Reception, SEN = 0) ............ 240
I2C Slave Mode (7-bit Reception, SEN = 0,
ADMSK = 01011) ............................................. 241
I2C Slave Mode (7-Bit Reception, SEN = 1) ............ 248
I2C Slave Mode (7-Bit Transmission) ....................... 242
I2C Slave Mode General Call Address Sequence
(7 or 10-Bit Addressing Mode) ......................... 250
I2C Stop Condition Receive or Transmit Mode ........ 261
MSSP I2C Bus Data .................................................417
MSSP I2C Bus Start/Stop Bits ................................. 417
Parallel Master Port Read ........................................408
Parallel Master Port Write ........................................ 409
Parallel Slave Port ...................................................407
Parallel Slave Port Read .................................. 160, 163
Parallel Slave Port Write .................................. 160, 163
Program Memory Read ............................................ 403
Program Memory Write ............................................ 404
PWM Auto-Shutdown (P1RSEN = 0,
Auto-Restart Disabled) ..................................... 217
PWM Auto-Shutdown (P1RSEN = 1,
Auto-Restart Enabled) ..................................... 217
PWM Direction Change ........................................... 214
PWM Direction Change at Near
100% Duty Cycle ............................................. 214
PWM Output ............................................................200
Read and Write, 8-Bit Data,
Demultiplexed Address .................................... 167
Read, 16-Bit Data, Demultiplexed Address ............. 170
Read, 16-Bit Multiplexed Data, Fully
Multiplexed 16-Bit Address ..............................172
Read, 16-Bit Multiplexed Data, Partially
Multiplexed Address ......................................... 171
Read, 8-Bit Data, Fully Multiplexed
16-Bit Address .................................................169
Read, 8-Bit Data, Partially Multiplexed Address ...... 167
Read, 8-Bit Data, Partially Multiplexed
Address, Enable Strobe ................................... 169
Read, 8-Bit Data, Wait States Enabled,
Partially Multiplexed Address .......................... 168
Repeated Start Condition ........................................ 256
Reset, Watchdog Timer (WDT), Oscillator Start-up
Timer (OST) and Power-up Timer (PWRT) ..... 405
Send Break Character Sequence ............................ 284
Slave Synchronization ............................................. 227
Slow Rise Time (MCLR Tied to VDD,
VDD Rise > TPWRT) ............................................ 53
SPI Mode (Master Mode) ......................................... 226
SPI Mode (Slave Mode, CKE = 0) ........................... 228
SPI Mode (Slave Mode, CKE = 1) ........................... 228
Synchronous Reception (Master Mode, SREN) ...... 287
Synchronous Transmission ..................................... 285
Synchronous Transmission (Through TXEN) .......... 286
Time-out Sequence on Power-up
(MCLR Not Tied to VDD), Case 1 ...................... 52
Time-out Sequence on Power-up
(MCLR Not Tied to VDD), Case 2 ...................... 53
Time-out Sequence on Power-up
(MCLR Tied to VDD, VDD Rise < TPWRT) ........... 52
Timer0 and Timer1 External Clock .......................... 406
Transition for Entry to Idle Mode ................................ 46
Transition for Entry to SEC_RUN Mode .................... 43
Transition for Entry to Sleep Mode ............................ 45
Transition for Two-Speed Start-up
(INTRC to HSPLL) ........................................... 324
Transition for Wake From Idle to Run Mode .............. 46
Transition for Wake From Sleep (HSPLL) ................. 45
Transition From RC_RUN Mode to
PRI_RUN Mode ................................................. 44
Transition From SEC_RUN Mode to
PRI_RUN Mode (HSPLL) .................................. 43
Transition to RC_RUN Mode ..................................... 44
Write, 16-Bit Multiplexed Data, Fully
Multiplexed 16-Bit Address .............................. 172
Write, 16-Bit Multiplexed Data, Partially
Multiplexed Address ........................................ 171
Write, 8-Bit Data, Demultiplexed Address ............... 170
Write, 8-Bit Data, Fully Multiplexed
16-Bit Address ................................................. 170
Write, 8-Bit Data, Partially Multiplexed
Address ........................................................... 168
Write, 8-Bit Data, Partially Multiplexed
Address, Enable Strobe ................................... 169
Write, 8-Bit Data, Wait States Enabled,
Partially Multiplexed Address .......................... 168
Timing Diagrams and Specifications
Capture/Compare/PWM Requirements
(Including ECCP Modules) .............................. 410
CLKO and I/O Requirements ........................... 402, 403
EUSART Synchronous Receive
Requirements .................................................. 419
EUSART Synchronous Transmission
Requirements .................................................. 419
Example SPI Mode Requirements
(Master Mode, CKE = 0) .................................. 411
Example SPI Mode Requirements
(Master Mode, CKE = 1) .................................. 412
Example SPI Mode Requirements
(Slave Mode, CKE = 0) .................................... 413
Example SPI Slave Mode Requirements
(CKE = 1) ......................................................... 414
External Clock Requirements .................................. 400
I2C Bus Data Requirements (Slave Mode) .............. 416
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 443
PIC18F87J11 FAMILY
I2C Bus Start/Stop Bits Requirements
(Slave Mode) ................................................... 415
Internal RC Accuracy (INTOSC, INTRC Sources) ... 401
MSSP I2C Bus Data Requirements ......................... 418
MSSP I2C Bus Start/Stop Bits Requirements .......... 417
Parallel Master Port Read Requirements ................ 408
Parallel Master Port Write ........................................ 409
Parallel Slave Port Requirements ............................ 407
PLL Clock ................................................................. 401
Program Memory Write Requirements .................... 404
Reset, Watchdog Timer (WDT), Oscillator
Start-up Timer (OST), Power-up
Timer (PWRT) and Brown-out Reset ............... 405
Timer0 and Timer1 External Clock
Requirements .................................................. 406
TSTFSZ ........................................................................... 369
Two-Speed Start-up ................................................. 313, 324
Two-Word Instructions
Example Cases .......................................................... 69
TXSTAx Register
BRGH Bit ................................................................. 273
V
VDDCORE/VCAP Pin .......................................................... 323
Voltage Reference Specifications .................................... 397
Voltage Regulator (On-Chip) ........................................... 323
Operation in Sleep Mode ......................................... 324
Power-up Requirements .......................................... 324
W
Watchdog Timer (WDT) ........................................... 313, 321
Associated Registers ............................................... 322
Control Register ....................................................... 321
During Oscillator Failure .......................................... 325
Programming Considerations .................................. 321
WCOL ...................................................... 255, 256, 257, 260
WCOL Status Flag ................................... 255, 256, 257, 260
WWW Address ................................................................ 431
WWW, On-Line Support ...................................................... 5
X
XORLW ........................................................................... 369
XORWF ........................................................................... 370
PIC18F87J11 FAMILY
DS39778C-page 444 Preliminary © 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc. Preliminary DS39778C-page 445
PIC18F87J11 FAMILY
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO. X/XX XXX
PatternPackageTemperature
Range
Device
Device PIC18F66J11/66J16/67J11(1),
PIC18F86J11/86J16/87J11(1),
PIC18F66J11/66J16/67J11T(2),
PIC18F86J11/86J16/87J11T(2)
Temperature Range I = -40°C to +85°C (Industrial)
Package PT = TQFP (Thin Quad Flatpack)
Pattern QTP, SQTP, Code or Special Requirements
(blank otherwise)
Examples:
a) PIC18F87J11-I/PT 301 = Industrial temp.,
TQFP package, QTP pattern #301.
b) PIC18F66J16T-I/PT = Tape and reel, Industrial
temp., TQFP package.
Note 1: F = Standard Voltage Range
2: T = in tape and reel
DS39778C-page 446 Preliminary © 2008 Microchip Technology Inc.
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01/02/08