2011 Microchip Technology Inc. Preliminary DS41609A
PIC16(L)F1508/9
Data Sheet
20-Pin Flash, 8-Bit Microcontrollers
with nanoWatt XLP Technology
DS41609A-page 2 Preliminary 2011 Microchip Technology Inc.
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ISBN: 978-1-61341-726-3
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
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
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and India. The Company’s quality system processes and procedures
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devices, Serial EEPROMs, microperipherals, nonvolatile memory and
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and manufacture of development systems is ISO 9001:2000 certified.
2011 Microchip Technology Inc. Preliminary DS41609A-page 3
High-Performance RISC CPU:
• C Compiler Optimized Architecture
• Only 49 Instructions
• Up to 14 Kbytes Linear Program Memory
Addressing
• Up to 512 bytes Linear Data Memory Addressing
• Operating Speed:
- DC – 20 MHz clock input
- DC – 200 ns instruction cycle
• Interrupt Capability with Automatic Context
Saving
• 16-Level Deep Hardware Stack with Optional
Overflow/Underflow Reset
• Direct, Indirect and Relative Addressing modes:
- Two full 16-bit File Select Registers (FSRs)
- FSRs can read program and data memory
Flexible Oscillator Structure:
• 16 MHz Internal Oscillator Block:
- Factory calibrated to ±1%, typical
- Software selectable frequency range from
16 MHz to 31 kHz
• 31 kHz Low-Power Internal Oscillator
• Three External Clock modes up to 20 MHz
Special Microcontroller Features:
• Operating Voltage Range:
- 1.8V to 3.6V (PIC16LF1508/9)
- 2.3V to 5.5V (PIC16F1508/9)
• Self-Programmable under Software Control
• Power-on Reset (POR)
• Power-up Timer (PWRT)
• Programmable Low-Power Brown-Out Reset
(LPBOR)
• Extended Watchdog Timer (WDT):
- Programmable period from 1 ms to 256s
• Programmable Code Protection
• In-Circuit Serial Programming™ (ICSP™) via Two
Pins
• Enhanced Low-Voltage Programming (LVP)
• In-Circuit Debug (ICD) via two pins
• Power-Saving Sleep mode:
- Low-Power Sleep mode
- Low-Power BOR (LPBOR)
• Integrated Temperature Indicator
• 128 Bytes High-Endurance Flash
- 100,000 write Flash endurance (minimum)
Extreme Low-Power Management
with nanoWatt XLP (PIC16LF1508/9):
• Standby Current:
- 25 nA @ 1.8V, typical
• Watchdog Timer Current:
- 300 nA @ 1.8V, typical
• Operating Current:
-30 A/MHz @ 1.8V, typical
• Timer1 Oscillator Current:
- 600 nA @ 32 kHz, 1.8V, typical
Peripheral Features:
• Analog-to-Digital Converter (ADC):
- 10-bit resolution
- 12 external channels
- 3 internal channels:
- Fixed Voltage Reference
- Digital-to-Analog Converter
- Temperature Indicator channel
- Auto acquisition capability
- Conversion available during Sleep
• 2 Comparators:
- Rail-to-rail inputs
- Power mode control
- Software controllable hysteresis
• Voltage Reference module:
- Fixed Voltage Reference (FVR) with 1.024V,
2.048V and 4.096V output levels
- Up to 1 rail-to-rail resistive 5-bit DAC with
positive reference selection
• 18 I/O Pins (1 Input-only Pin):
- High current sink/source 25 mA/25 mA
- Individually programmable weak pull-ups
- Individually programmable
interrupt-on-change (IOC) pins
• Timer0: 8-Bit Timer/Counter with 8-Bit
Programmable Prescaler
• Enhanced Timer1:
- 16-bit timer/counter with prescaler
- External Gate Input mode
• Timer2: 8-Bit Timer/Counter with 8-Bit Period
Register, Prescaler and Postscaler
• Four 10-bit PWM modules
• Master Synchronous Serial Port (MSSP) with SPI
and I2C™ with:
- 7-bit address masking
- SMBus/PMBus™ compatibility
20-Pin Flash, 8-Bit Microcontrollers with nanoWatt XLP Technology
PIC16(L)F1508/9
PIC16(L)F1508/9
DS41609A-page 4 Preliminary 2011 Microchip Technology Inc.
Peripheral Features (Continued):
• Enhanced Universal Synchronous Asynchronous
Receiver Transmitter (EUSART)
- RS-232, RS-485 and LIN compatible
- Auto-Baud Detect
- Auto-wake-up on Start
• 4 Configurable Logic Cell (CLC) modules:
- 16 selectable input source signals
- Four inputs per module
- Software control of combinational/sequential
logic/state/clock functions
- AND/OR/XOR/D Flop/D Latch/SR/JK
- External or internal inputs/outputs
- Operation while in Sleep
• Numerically Controlled Oscillator (NCO):
- 20-bit accumulator
- 16-bit increment
- True linear frequency control
- High-speed clock input
- Selectable Output modes
- Fixed Duty Cycle (FDC) mode
- Pulse Frequency (PF) mode
• Complementary Waveform Generator (CWG):
- 8 selectable signal sources
- Selectable falling and rising edge dead-band
control
- Polarity control
- 4 auto-shutdown sources
- Multiple input sources: PWM, CLC, NCO
PIC12(L)F1501/PIC16(F)L150X Family Types
Device
Data Sheet Index
Program Memory
Flash (words)
Data SRAM
(bytes)
I/O’s(2)
10-bit ADC (ch)
Comparators
DAC
Timers
(8/16-bit)
PWM
EUSART
MSSP (I2C/SPI)
CWG
CLC
NCO
Debug(1)
XLP
PIC12(L)F1501 (1) 1024 64 6 4 1 1 2/1 4 — — 1 2 1 H —
PIC16(L)F1503 (2) 2048 128 12 8 2 1 2/1 4 — 1 1 2 1 H —
PIC16(L)F1507 (3) 2048 128 18 12 — — 2/1 4 — — 1 2 1 H —
PIC16(L)F1508 (4) 4096 256 18 12 2 1 2/1 4 1 1 1 4 1 I/H Y
PIC16(L)F1509 (4) 8192 512 18 12 2 1 2/1 4 1 1 1 4 1 I/H Y
Note 1: I - Debugging, Integrated on Chip; H - Debugging, Requires Debug Header.
2: One pin is input-only.
Data Sheet Index: (Unshaded devices are described in this document.)
1: Future Product PIC12(L)F1501 Data Sheet, 8-Pin Flash, 8-bit Microcontrollers.
2: DS41607 PIC16(L)F1503 Data Sheet, 14-Pin Flash, 8-bit Microcontrollers.
3: DS41586 PIC16(L)F1507 Data Sheet, 20-Pin Flash, 8-bit Microcontrollers.
4: DS41609 PIC16(L)F1508/1509 Data Sheet, 20-Pin Flash, 8-bit Microcontrollers.
2011 Microchip Technology Inc. Preliminary DS41609A-page 5
PIC16(L)F1508/9
FIGURE 1: 20-PIN PDIP, SOIC, SSOP PACKAGE DIAGRAM FOR PIC16(L)F1508/9
FIGURE 2: 20-PIN QFN PACKAGE DIAGRAM FOR PIC16(L)F1508/9
PIC16F1508/9
PIC16LF1508/9
1
2
3
4
14
13
12
11
5
6
7
10
9
8
VDD
RA5
RA4
MCLR/VPP/RA3
RC5
RC4
VSS
RA0/ICSPDAT
RA1/ICSPCLK
RA2
RC0
RC1
RC2
RC3
PDIP, SOIC, SSOP
Note: See Tabl e 1 for location of all peripheral functions.
18
17
16
15
20
19
RC6
RC7
RB7
RB4
RB5
RB6
PIC16F1508/9
PIC16LF1508/9
QFN 4x4
Note: See Tabl e 1 for location of all peripheral functions.
15 RA1/ICSPCLK
RA2
RC0
RC1
RC2
11
12
13
14
67
RC7
RB7
RB4
RB5
RB6
8910
2
3
1
18
1920 16
17
5
4
VDD
RA5
RA4
MCLR/VPP/RA3
RC5
RC4
RC3
RC6
VSS
RA0/ICSPDAT
PIC16(L)F1508/9
DS41609A-page 6 Preliminary 2011 Microchip Technology Inc.
TABLE 1: 20-PIN ALLOCATION TABLE (PIC16(L)F1508/9)
I/O
20-Pin PDIP/SOIC/SSOP
20-Pin QFN
A/D
Reference
Comparator
Timers
EUSART
MSSP
CWG
NCO
CLC
PWM
Interrupt
Pull-up
Basic
RA0 19 16 AN0 DACOUT1 C1IN+ ———— — — — IOC YICSPDAT
ICDDAT
RA1 18 15 AN1 VREF+C1IN0-
C2IN0-
——— — — CLC4IN1 —IOC YICSPCLK
ICDCLK
RA2 17 14 AN2 DACOUT2 C1OUT T0CKI — — CWG1FLT —CLC1(1) PWM3 INT/
IOC
Y —
RA3 4 1 — — — T1G(2) —SS
(2) — — CLC1IN0 —IOC YMCLR
VPP
RA4 320 AN3 — — SOSCO
T1G(1) — — — — — — IOC YCLKOUT
OSC2
RA5 219 — — — SOSCI
T1CKI
—— —NCO1CLK — — IOC YCLKIN
OSC1
RB4 13 10 AN10 — — — — SDA/SDI — — CLC3IN0 —IOC Y —
RB5 12 9AN11 — — —RX/DT— — — CLC4IN0 —IOC Y —
RB6 11 8 — — — — — SCL/SCK — — — — IOC Y —
RB7 10 7 — — — —TX/CK— — — CLC3 —IOC Y —
RC0 16 13 AN4 —C2IN+ — — — — — CLC2 — — — —
RC1 15 12 AN5 —C1IN1-
C2IN1-
——— —NCO1(1) —PWM4 — — —
RC2 14 11 AN6 —C1IN2-
C2IN2-
— — — — — — — — — —
RC3 7 4 AN7 —C1IN3- ——— — — CLC2IN0 PWM2 — — —
RC4 6 3 — — C2OUT ———CWG1B —CLC4
CLC2IN1
— — — —
RC5 5 2 — — — ———CWG1A —CLC1(2) PWM1 — — —
RC6 8 5 AN8 — — — — SS(1) —NCO1(2) CLC3IN1 — — — —
RC7 9 6 AN9 — — ——SDO — — CLC1IN1 — — — —
VDD 118 — — — — — — — — — — — — VDD
VSS 2017—— — ——— — — ————VSS
Note 1: Default location for peripheral pin function. Alternate location can be selected using the APFCON register.
2: Alternate location for peripheral pin function selected by the APFCON register.
2011 Microchip Technology Inc. Preliminary DS41609A-page 7
PIC16(L)F1508/9
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 9
2.0 Enhanced Mid-Range CPU ........................................................................................................................................................ 15
3.0 Memory Organization ................................................................................................................................................................. 17
4.0 Device Configuration.................................................................................................................................................................. 43
5.0 Oscillator Module (With Fail-Safe Clock Monitor)....................................................................................................................... 49
6.0 Resets ........................................................................................................................................................................................ 65
7.0 Interrupts .................................................................................................................................................................................... 73
8.0 Power-Down Mode (Sleep) ........................................................................................................................................................ 87
9.0 Watchdog Timer ......................................................................................................................................................................... 91
10.0 Flash Program Memory Control ................................................................................................................................................. 95
11.0 I/O Ports ................................................................................................................................................................................... 111
12.0 Interrupt-On-Change ................................................................................................................................................................ 125
13.0 Fixed Voltage Reference (FVR) ............................................................................................................................................... 131
14.0 Temperature Indicator Module ................................................................................................................................................. 133
15.0 Analog-to-Digital Converter (ADC) Module .............................................................................................................................. 135
16.0 Digital-to-Analog Converter (DAC) Module .............................................................................................................................. 149
17.0 Comparator Module.................................................................................................................................................................. 153
18.0 Timer0 Module ......................................................................................................................................................................... 163
19.0 Timer1 Module with Gate Control............................................................................................................................................. 167
20.0 Timer2 Module ......................................................................................................................................................................... 179
21.0 Master Synchronous Serial Port Module.................................................................................................................................. 183
22.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................................... 237
23.0 Pulse Width Modulation (PWM) Module................................................................................................................................... 265
24.0 Configurable Logic Cell (CLC).................................................................................................................................................. 271
25.0 Numerically Controlled Oscillator (NCO) Module ..................................................................................................................... 287
26.0 Complementary Waveform Generator (CWG) Module ............................................................................................................ 297
27.0 In-Circuit Serial Programming™ (ICSP™) ............................................................................................................................... 313
28.0 Instruction Set Summary.......................................................................................................................................................... 315
29.0 Electrical Specifications............................................................................................................................................................ 329
30.0 DC and AC Characteristics Graphs and Charts ....................................................................................................................... 357
31.0 Development Support............................................................................................................................................................... 359
32.0 Packaging Information.............................................................................................................................................................. 363
Appendix A: Data Sheet Revision History.......................................................................................................................................... 373
Index .................................................................................................................................................................................................. 375
The Microchip Web Site..................................................................................................................................................................... 381
Customer Change Notification Service .............................................................................................................................................. 381
Customer Support .............................................................................................................................................................................. 381
Reader Response .............................................................................................................................................................................. 382
Product Identification System ............................................................................................................................................................ 383
PIC16(L)F1508/9
DS41609A-page 8 Preliminary 2011 Microchip Technology Inc.
TO OUR VALUED CUSTOMERS
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2011 Microchip Technology Inc. Preliminary DS41609A-page 9
PIC16(L)F1508/9
1.0 DEVICE OVERVIEW
The PIC16(L)F1508/9 are described within this data
sheet. They are available in 14-pin packages. Figure 1-1
shows a block diagram of the PIC16(L)F1508/9 devices.
Tables 1-2 shows the pinout descriptions.
Reference Table 1-1 for peripherals available per
device.
TABLE 1-1: DEVICE PERIPHERAL SUMMARY
Peripheral
PIC16F1501
PIC16LF1501
PIC16F1503
PIC16LF1503
PIC16F1507
PIC16LF1507
PIC16F1508/9
PIC16LF1508/9
Analog-to-Digital Converter (ADC) ●●●●●●●●
Complementary Wave Generator (CWG) ●●●●●●●●
Digital-to-Analog Converter (DAC) ● ● ● ● ●●
Enhanced Universal
Synchronous/Asynchronous
Receiver/Transmitter (EUSART)
●●
Fixed Voltage Reference (FVR) ●●●●●●●●
Numerically Controlled Oscillator (NCO) ●●●●●●●●
Temperature Indicator ●●●●●●●●
Comparators
C1 ● ● ● ● ●●
C2 ● ● ●●
Configurable Logic Cell (CLC)
CLC1 ●●●●●●●●
CLC2 ●●●●●●●●
CLC3 ●●
CLC4 ●●
Master Synchronous Serial Ports
MSSP1 ● ● ●●
PWM Modules
PWM1 ●●●●●●●●
PWM2 ●●●●●●●●
PWM3 ●●●●●●●●
PWM4 ●●●●●●●●
Timers
Timer0 ●●●●●●●●
Timer1 ●●●●●●●●
Timer2 ●●●●●●●●
PIC16(L)F1508/9
DS41609A-page 10 Preliminary 2011 Microchip Technology Inc.
FIGURE 1-1: PIC16(L)F1508/9 BLOCK DIAGRAM
PORTC
Note 1: See applicable chapters for more information on peripherals.
2: See Ta b le 1 - 1 for peripherals available on specific devices.
CPU
Program
Flash Memory
RAM
Timing
Generation
INTRC
Oscillator
MCLR
(Figure 2-1)
NCO1
PWM4
Timer2Timer1Timer0
CLC4
PWM1 PWM2 PWM3
PORTA
CWG1
CLC3
ADC
10-Bit FVR
Temp.
Indicator
OSC1/CLKIN
OSC2/CLKOUT
MSSP1
C2C1
DAC
PORTB
CLC2CLC1
EUSART
2011 Microchip Technology Inc. Preliminary DS41609A-page 11
PIC16(L)F1508/9
TABLE 1-2: PIC16(L)F1508/9 PINOUT DESCRIPTION
Name Function Input
Type
Output
Type Description
RA0/AN0/C1IN+/DACOUT1/
ICSPDAT/ICDDAT
RA0 TTL CMOS General purpose I/O.
AN0 AN — A/D Channel input.
C1IN+ AN — Comparator positive input.
DACOUT1 — AN Digital-to-Analog Converter output.
ICSPDAT ST CMOS ICSP™ Data I/O.
ICDDAT ST CMOS In-Circuit Debug data.
RA1/AN1/CLC4IN1/VREF+/
C1IN0-/C2IN0-/ICSPCLK/
ICDCLK
RA1 TTL CMOS General purpose I/O.
AN1 AN — A/D Channel input.
CLC4IN1 ST — Configurable Logic Cell source input.
VREF+ AN — A/D Positive Voltage Reference input.
C1IN0- AN — Comparator negative input.
C2IN0- AN — Comparator negative input.
ICSPCLK ST — ICSP Programming Clock.
ICDCLK ST — In-Circuit Debug Clock.
RA2/AN2/C1OUT/DACOUT2/
T0CKI/INT/PWM3/CLC1(1)/
CWG1FLT
RA2 ST CMOS General purpose I/O.
AN2 AN — A/D Channel input.
C1OUT — CMOS Comparator output.
DACOUT2 — AN Digital-to-Analog Converter output.
T0CKI ST — Timer0 clock input.
INT ST — External interrupt.
PWM3 — CMOS PWM output.
CLC1 — CMOS Configurable Logic Cell source output.
CWG1FLT ST — Complementary Waveform Generator Fault input.
RA3/CLC1IN0/VPP/T1G(2)/SS(2)/
MCLR
RA3 TTL — General purpose input with IOC and WPU.
CLC1IN0 ST — Configurable Logic Cell source input.
VPP HV — Programming voltage.
T1G ST — Timer1 Gate input.
SS ST — Slave Select input.
MCLR ST — Master Clear with internal pull-up.
RA4/AN3/SOSCO/
CLKOUT/T1G
RA4 TTL CMOS General purpose I/O.
AN3 AN — A/D Channel input.
SOSCO XTAL XTAL Secondary Oscillator Connection.
CLKOUT — CMOS FOSC/4 output.
T1G ST — Timer1 Gate input.
RA5/CLKIN/T1CKI/NCO1CLK/
SOSCI
RA5 TTL CMOS General purpose I/O.
CLKIN CMOS — External clock input (EC mode).
T1CKI ST — Timer1 clock input.
NCO1CLK ST — Numerically Controlled Oscillator Clock source input.
SOSCI XTAL XTAL Secondary Oscillator Connection.
Legend: AN = Analog input or output CMOS= CMOS compatible input or output OD = Open Drain
TTL = TTL compatible input ST = Schmitt Trigger input with CMOS levels I2C™ = Schmitt Trigger input with I2C
HV = High Voltage XTAL = Crystal levels
Note 1: Default location for peripheral pin function. Alternate location can be selected using the APFCON register.
2: Alternate location for peripheral pin function selected by the APFCON register.
PIC16(L)F1508/9
DS41609A-page 12 Preliminary 2011 Microchip Technology Inc.
RB4/AN10/CLC3IN0/SDA/SDI RB4 TTL CMOS General purpose I/O.
AN10 AN — A/D Channel input.
CLC3IN0 ST — Configurable Logic Cell source input.
SDA I2CODI
2C data input/output.
SDI CMOS — SPI data input.
RB5/AN11/CLC4IN0/RX/DT RB5 TTL CMOS General purpose I/O.
AN11 AN — A/D Channel input.
CLC4IN0 ST — Configurable Logic Cell source input.
RX ST — USART asynchronous input.
DT ST CMOS USART synchronous data.
RB6/SCL/SCK RB6 TTL CMOS General purpose I/O.
SCL I2CODI
2C™ clock.
SCK ST CMOS SPI clock.
RB7/CLC3/TX/CK RB7 TTL CMOS General purpose I/O.
CLC3 — CMOS Configurable Logic Cell source output.
TX — CMOS USART asynchronous transmit.
CK ST CMOS USART synchronous clock.
RC0/AN4/CLC2/C2IN+ RC0 TTL CMOS General purpose I/O.
AN4 AN — A/D Channel input.
CLC2 — CMOS Configurable Logic Cell source output.
C2IN+ AN — Comparator positive input.
RC1/AN5/C1IN1-/C2IN1-/PWM4/
NCO1(1)
RC1 TTL CMOS General purpose I/O.
AN5 AN — A/D Channel input.
C1IN1- AN — Comparator negative input.
C2IN1- AN — Comparator negative input.
PWM4 — CMOS PWM output.
NCO1 — CMOS Numerically Controlled Oscillator is source output.
RC2/AN6/C1IN2-/C2IN2- RC2 TTL CMOS General purpose I/O.
AN6 AN — A/D Channel input.
C1IN2- AN — Comparator negative input.
C2IN2- AN — Comparator negative input.
RC3/AN7/C1IN3-/PWM2/
CLC2IN0
RC3 TTL CMOS General purpose I/O.
AN7 AN — A/D Channel input.
C1IN3- AN — Comparator negative input.
PWM2 — CMOS PWM output.
CLC2IN0 ST — Configurable Logic Cell source input.
RC4/C2OUT/CLC2IN1/CLC4/
CWG1B
RC4 TTL CMOS General purpose I/O.
C2OUT — CMOS Comparator output.
CLC2IN1 ST — Configurable Logic Cell source input.
CLC4 — CMOS Configurable Logic Cell source output.
CWG1B — CMOS CWG complementary output.
TABLE 1-2: PIC16(L)F1508/9 PINOUT DESCRIPTION (CONTINUED)
Name Function Input
Type
Output
Type Description
Legend: AN = Analog input or output CMOS= CMOS compatible input or output OD = Open Drain
TTL = TTL compatible input ST = Schmitt Trigger input with CMOS levels I2C™ = Schmitt Trigger input with I2C
HV = High Voltage XTAL = Crystal levels
Note 1: Default location for peripheral pin function. Alternate location can be selected using the APFCON register.
2: Alternate location for peripheral pin function selected by the APFCON register.
2011 Microchip Technology Inc. Preliminary DS41609A-page 13
PIC16(L)F1508/9
RC5/PWM1/CLC1(2)/
CWG1A
RC5 TTL CMOS General purpose I/O.
PWM1 — CMOS PWM output.
CLC1 — CMOS Configurable Logic Cell source output.
CWG1A — CMOS CWG primary output.
RC6/AN8/NCO1(2)/CLC3IN1/
SS(1)
RC6 TTL CMOS General purpose I/O.
AN8 AN — A/D Channel input.
NCO1 — CMOS Numerically Controlled Oscillator source output.
CLC3IN1 ST — Configurable Logic Cell source input.
SS ST — Slave Select input.
RC7/AN9/CLC1IN1/SDO RC7 TTL CMOS General purpose I/O.
AN9 AN — A/D Channel input.
CLC1IN1 ST — Configurable Logic Cell source input.
SDO — CMOS SPI data output.
VDD VDD Power — Positive supply.
VSS VSS Power — Ground reference.
TABLE 1-2: PIC16(L)F1508/9 PINOUT DESCRIPTION (CONTINUED)
Name Function Input
Type
Output
Type Description
Legend: AN = Analog input or output CMOS= CMOS compatible input or output OD = Open Drain
TTL = TTL compatible input ST = Schmitt Trigger input with CMOS levels I2C™ = Schmitt Trigger input with I2C
HV = High Voltage XTAL = Crystal levels
Note 1: Default location for peripheral pin function. Alternate location can be selected using the APFCON register.
2: Alternate location for peripheral pin function selected by the APFCON register.
PIC16(L)F1508/9
DS41609A-page 14 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 15
PIC16(L)F1508/9
2.0 ENHANCED MID-RANGE CPU
This family of devices contain an enhanced mid-range
8-bit CPU core. The CPU has 49 instructions. Interrupt
capability includes automatic context saving. The
hardware stack is 16 levels deep and has Overflow and
Underflow Reset capability. Direct, Indirect, and
Relative addressing modes are available. Two File
Select Registers (FSRs) provide the ability to read
program and data memory.
• Automatic Interrupt Context Saving
• 16-level Stack with Overflow and Underflow
• File Select Registers
• Instruction Set
2.1 Automatic Interrupt Context
Saving
During interrupts, certain registers are automatically
saved in Shadow registers and restored when returning
from the interrupt. This saves stack space and user
code. See Section 7.5 “Automatic Context Saving”,
for more information.
2.2 16-Level Stack with Overflow and
Underflow
These devices have an external stack memory 15 bits
wide and 16 words deep. A Stack Overflow or Under-
flow will set the appropriate bit (STKOVF or STKUNF)
in the PCON register, and if enabled will cause a soft-
ware Reset. See section Section 3.4 “Stack” for more
details.
2.3 File Select Registers
There are two 16-bit File Select Registers (FSR). FSRs
can access all file registers and program memory,
which allows one Data Pointer for all memory. When an
FSR points to program memory, there is one additional
instruction cycle in instructions using INDF to allow the
data to be fetched. General purpose memory can now
also be addressed linearly, providing the ability to
access contiguous data larger than 80 bytes. There are
also new instructions to support the FSRs. See
Section 3.5 “Indirect Addressing” for more details.
2.4 Instruction Set
There are 49 instructions for the enhanced mid-range
CPU to support the features of the CPU. See
Section 28.0 “Instruction Set Summary” for more
details.
PIC16(L)F1508/9
DS41609A-page 16 Preliminary 2011 Microchip Technology Inc.
FIGURE 2-1: CORE BLOCK DIAGRAM
Data Bus 8
14
Program
Bus
Instruction reg
Program Counter
8 Level Stack
(13-bit)
Direct Addr 7
12
Addr MUX
FSR reg
STATUS reg
MUX
ALU
Instruction
Decode &
Control
Timing
Generation
CLKIN
CLKOUT
8
8
12
3
Internal
Oscillator
Block
Configuration Data Bus 8
14
Program
Bus
Instruction reg
Program Counter
8 Level Stack
(13-bit)
Direct Addr 7
Addr MUX
FSR reg
STATUS reg
MUX
ALU
W Reg
Instruction
Decode &
Control
Timing
Generation
8
8
3
Internal
Oscillator
Block
Configuration 15 Data Bus 8
14
Program
Bus
Instruction Reg
Program Counter
16-Level Stack
(15-bit)
Direct Addr 7
RAM Addr
Addr MUX
Indirect
Addr
FSR0 Reg
STATUS Reg
MUX
ALU
Instruction
Decode and
Control
Timing
Generation
8
8
3
Internal
Oscillator
Block
Configuration
Flash
Program
Memory RAM
FSR regFSR reg
FSR1 Reg
15
15
MUX
15
Program Memory
Read (PMR)
12
FSR regFSR reg
BSR Reg
5
Power-up
Timer
Power-on
Reset
Watchdog
Timer
VDD
Brown-out
Reset
VSSVDD VSSVDD VSS
2011 Microchip Technology Inc. Preliminary DS41609A-page 17
PIC16(L)F1508/9
3.0 MEMORY ORGANIZATION
These devices contain the following types of memory:
• Program Memory
- Configuration Words
- Device ID
-User ID
- Flash Program Memory
• Data Memory
- Core Registers
- Special Function Registers
- General Purpose RAM
- Common RAM
The following features are associated with access and
control of program memory and data memory:
• PCL and PCLATH
•Stack
• Indirect Addressing
3.1 Program Memory Organization
The enhanced mid-range core has a 15-bit program
counter capable of addressing 32K x 14 program
memory space. Table 3-1 shows the memory sizes
implemented. Accessing a location above these
boundaries will cause a wrap-around within the
implemented memory space. The Reset vector is at
0000h and the interrupt vector is at 0004h (See
Figure 3-1).
TABLE 3-1: DEVICE SIZES AND ADDRESSES
Device Program Memory
Space (Words)
Last Program Memory
Address
High-Endurance Flash
Memory Address Range (1)
PIC16F1508
PIC16LF1508 4,096 0FFFh 0F80h-0FFFh
PIC16F1509
PIC16LF1509 8,192 1FFFh 1F80h-1FFFh
Note 1: High-endurance Flash applies to low byte of each address in the range.
PIC16(L)F1508/9
DS41609A-page 18 Preliminary 2011 Microchip Technology Inc.
FIGURE 3-1: PROGRAM MEMORY MAP
AND STACK FOR
PIC16(L)F1508
FIGURE 3-2: PROGRAM MEMORY MAP
AND STACK FOR
PIC16(L)F1509
PC<14:0>
15
0000h
0004h
Stack Level 0
Stack Level 15
Reset Vector
Interrupt Vector
CALL, CALLW
RETURN, RETLW
Stack Level 1
0005h
On-chip
Program
Memory
Page 0
07FFh
Rollover to Page 0
0800h
0FFFh
1000h
7FFFh
Page 1
Rollover to Page 1
Interrupt, RETFIE
PC<14:0>
15
0000h
0004h
Stack Level 0
Stack Level 15
Reset Vector
Interrupt Vector
Stack Level 1
0005h
On-chip
Program
Memory
Page 0
07FFh
Rollover to Page 0
0800h
0FFFh
1000h
7FFFh
Page 1
Rollover to Page 3
Page 2
Page 3
17FFh
1800h
1FFFh
2000h
CALL, CALLW
RETURN, RETLW
Interrupt, RETFIE
2011 Microchip Technology Inc. Preliminary DS41609A-page 19
PIC16(L)F1508/9
3.1.1 READING PROGRAM MEMORY AS
DATA
There are two methods of accessing constants in pro-
gram memory. The first method is to use tables of
RETLW instructions. The second method is to set an
FSR to point to the program memory.
3.1.1.1 RETLW Instruction
The RETLW instruction can be used to provide access
to tables of constants. The recommended way to create
such a table is shown in Example 3-1.
EXAMPLE 3-1: RETLW INSTRUCTION
The BRW instruction makes this type of table very sim-
ple to implement. If your code must remain portable
with previous generations of microcontrollers, then the
BRW instruction is not available so the older table read
method must be used.
3.1.1.2 Indirect Read with FSR
The program memory can be accessed as data by set-
ting bit 7 of the FSRxH register and reading the match-
ing INDFx register. The MOVIW instruction will place the
lower 8 bits of the addressed word in the W register.
Writes to the program memory cannot be performed via
the INDF registers. Instructions that access the pro-
gram memory via the FSR require one extra instruction
cycle to complete. Example 3-2 demonstrates access-
ing the program memory via an FSR.
The HIGH directive will set bit<7> if a label points to a
location in program memory.
EXAMPLE 3-2: ACCESSING PROGRAM
MEMORY VIA FSR
constants
BRW ;Add Index in W to
;program counter to
;select data
RETLW DATA0 ;Index0 data
RETLW DATA1 ;Index1 data
RETLW DATA2
RETLW DATA3
my_function
;… LOTS OF CODE…
MOVLW DATA_INDEX
call constants
;… THE CONSTANT IS IN W
constants
RETLW DATA0 ;Index0 data
RETLW DATA1 ;Index1 data
RETLW DATA2
RETLW DATA3
my_function
;… LOTS OF CODE…
MOVLW LOW constants
MOVWF FSR1L
MOVLW HIGH constants
MOVWF FSR1H
MOVIW 0[FSR1]
;THE PROGRAM MEMORY IS IN W
PIC16(L)F1508/9
DS41609A-page 20 Preliminary 2011 Microchip Technology Inc.
3.2 Data Memory Organization
The data memory is partitioned in 32 memory banks
with 128 bytes in a bank. Each bank consists of
(Figure 3-3):
• 12 core registers
• 20 Special Function Registers (SFR)
• Up to 80 bytes of General Purpose RAM (GPR)
• 16 bytes of common RAM
The active bank is selected by writing the bank number
into the Bank Select Register (BSR). Unimplemented
memory will read as ‘0’. All data memory can be
accessed either directly (via instructions that use the
file registers) or indirectly via the two File Select
Registers (FSR). See Section 3.5 “Indirect
Addressing” for more information.
Data memory uses a 12-bit address. The upper 7-bits
of the address define the Bank address and the lower
5-bits select the registers/RAM in that bank.
3.2.1 CORE REGISTERS
The core registers contain the registers that directly
affect the basic operation. The core registers occupy
the first 12 addresses of every data memory bank
(addresses x00h/x08h through x0Bh/x8Bh). These
registers are listed below in Ta ble 3 - 2 . For detailed
information, see Tab le 3 -8 .
TABLE 3-2: CORE REGISTERS
Addresses BANKx
x00h or x80h INDF0
x01h or x81h INDF1
x02h or x82h PCL
x03h or x83h STATUS
x04h or x84h FSR0L
x05h or x85h FSR0H
x06h or x86h FSR1L
x07h or x87h FSR1H
x08h or x88h BSR
x09h or x89h WREG
x0Ah or x8Ah PCLATH
x0Bh or x8Bh INTCON
2011 Microchip Technology Inc. Preliminary DS41609A-page 21
PIC16(L)F1508/9
3.2.1.1 STATUS Register
The STATUS register, shown in Register 3-1, contains:
• the arithmetic status of the ALU
• the Reset status
The STATUS register can be the destination for any
instruction, like any other register. If the STATUS
register is the destination for an instruction that affects
the Z, DC or C bits, then the write to these three bits is
disabled. These bits are set or cleared according to the
device logic. Furthermore, the TO and PD bits are not
writable. Therefore, the result of an instruction with the
STATUS register as destination may be different than
intended.
For example, CLRF STATUS will clear the upper three
bits and set the Z bit. This leaves the STATUS register
as ‘000u u1uu’ (where u = unchanged).
It is recommended, therefore, that only BCF, BSF,
SWAPF and MOVWF instructions are used to alter the
STATUS register, because these instructions do not
affect any Status bits. For other instructions not
affecting any Status bits (Refer to Section 28.0
“Instruction Set Summary”).
Note 1: The C and DC bits operate as Borrow
and Digit Borrow out bits, respectively, in
subtraction.
REGISTER 3-1: STATUS: STATUS REGISTER
U-0 U-0 U-0 R-1/q R-1/q R/W-0/u R/W-0/u R/W-0/u
— — — TO PD ZDC
(1) C(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared q = Value depends on condition
bit 7-5 Unimplemented: Read as ‘0’
bit 4 TO: Time-Out bit
1 = After power-up, CLRWDT instruction or SLEEP instruction
0 = A WDT time-out occurred
bit 3 PD: Power-Down bit
1 = After power-up or by the CLRWDT instruction
0 = By execution of the SLEEP instruction
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/Digit Borrow bit (ADDWF, ADDLW, SUBLW, SUBWF instructions)(1)
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(1) (ADDWF, ADDLW, SUBLW, SUBWF instructions)(1)
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 two’s complement of the
second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high-order or low-order
bit of the source register.
PIC16(L)F1508/9
DS41609A-page 22 Preliminary 2011 Microchip Technology Inc.
3.2.2 SPECIAL FUNCTION REGISTER
The Special Function Registers are registers used by
the application to control the desired operation of
peripheral functions in the device. The Special Function
Registers occupy the 20 bytes after the core registers of
every data memory bank (addresses x0Ch/x8Ch
through x1Fh/x9Fh). The registers associated with the
operation of the peripherals are described in the appro-
priate peripheral chapter of this data sheet.
3.2.3 GENERAL PURPOSE RAM
There are up to 80 bytes of GPR in each data memory
bank. The Special Function Registers occupy the 20
bytes after the core registers of every data memory
bank (addresses x0Ch/x8Ch through x1Fh/x9Fh).
3.2.3.1 Linear Access to GPR
The general purpose RAM can be accessed in a
non-banked method via the FSRs. This can simplify
access to large memory structures. See Section 3.5.2
“Linear Data Memory” for more information.
3.2.4 COMMON RAM
There are 16 bytes of common RAM accessible from all
banks.
FIGURE 3-3: BANKED MEMORY
PARTITIONING
3.2.5 DEVICE MEMORY MAPS
The memory maps for PIC16(L)F1508/9 are as shown
in Table 3-5 and Table 3 - 6 .
0Bh
0Ch
1Fh
20h
6Fh
70h
7Fh
00h
Common RAM
(16 bytes)
General Purpose RAM
(80 bytes maximum)
Core Registers
(12 bytes)
Special Function Registers
(20 bytes maximum)
Memory Region
7-bit Bank Offset
2011 Microchip Technology Inc. Preliminary DS41609A-page 23
PIC16(L)F1508/9
TABLE 3-3: PIC16(L)F1508 MEMORY MAP, BANK 1-7
BANK 0 BANK 1 BANK 2 BANK 3 BANK 4 BANK 5 BANK 6 BANK 7
000h
Core Registers
(Table 3-2)
080h
Core Registers
(Table 3-2)
100h
Core Registers
(Table 3-2)
180h
Core Registers
(Table 3-2)
200h
Core Registers
(Table 3-2)
280h
Core Registers
(Table 3-2)
300h
Core Registers
(Table 3-2)
380h
Core Registers
(Table 3-2)
00Bh 08Bh 10Bh 18Bh 20Bh 28Bh 30Bh 38Bh
00Ch PORTA 08Ch TRISA 10Ch LATA 18Ch ANSELA 20Ch WPUA 28Ch — 30Ch — 38Ch —
00Dh PORTB 08Dh TRISB 10Dh LATB 18Dh ANSELB 20Dh WPUB 28Dh — 30Dh — 38Dh —
00Eh PORTC 08Eh TRISC 10Eh LATC 18Eh ANSELC 20Eh —28Eh—30Eh—38Eh—
00Fh —08Fh—10Fh—18Fh—20Fh—28Fh—30Fh—38Fh—
010h —090h—110h—190h—210h—290h—310h — 390h —
011h PIR1 091h PIE1 111h CM1CON0 191h PMADRL 211h SSP1BUF 291h —311h —391h IOCAP
012h PIR2 092h PIE2 112h CM1CON1 192h PMADRH 212h SSP1ADD 292h —312h —392h IOCAN
013h PIR3 093h PIE3 113h CM2CON0 193h PMDATL 213h SSP1MSK 293h —313h —393h IOCAF
014h —094h— 114h CM2CON1 194h PMDATH 214h SSP1STAT 294h —314h —394h IOCBP
015h TMR0 095h OPTION_REG 115h CMOUT 195h PMCON1 215h SSP1CON1 295h —315h —395h IOCBN
016h TMR1L 096h PCON 116h BORCON 196h PMCON2 216h SSP1CON2 296h — 316h — 396h IOCBF
017h TMR1H 097h WDTCON 117h FVRCON 197h VREGCON 217h SSP1CON3 297h — 317h — 397h —
018h T1CON 098h —118h
DACCON0 198h —218h—298h — 318h — 398h —
019h T1GCON 099h OSCCON 119h DACCON1 199h RCREG 219h —299h— 319h — 399h —
01Ah TMR2 09Ah OSCSTAT 11Ah —19Ah
TXREG 21Ah —29Ah—31Ah—39Ah—
01Bh PR2 09BhADRESL11Bh —19Bh
SPBRG 21Bh —29Bh—31Bh—39Bh —
01Ch T2CON 09Ch ADRESH 11Ch — 19Ch SPBRGH 21Ch — 29Ch — 31Ch —39Ch —
01Dh — 09Dh ADCON0 11Dh APFCON 19Dh RCSTA 21Dh —29Dh —31Dh —39Dh —
01Eh —09Eh ADCON1 11Eh —19Eh TXSTA 21Eh —29Eh —31Eh —39Eh —
01Fh —09Fh ADCON2 11Fh —19Fh
BAUDCON 21Fh —29Fh —31Fh —39Fh —
020h
General
Purpose
Register
80 Bytes
0A0h
General
Purpose
Register
80 Bytes
120h
General
Purpose
Register
80 Bytes
1A0h
Unimplemented
Read as ‘0’
220h
Unimplemented
Read as ‘0’
2A0h
Unimplemented
Read as ‘0’
320h
Unimplemented
Read as ‘0’
3A0h
Unimplemented
Read as ‘0’
0EFh
06Fh 16Fh 1EFh 26Fh 2EFh 36Fh 3EFh
070h
Common RAM
0F0h Common RAM
(Accesses
70h – 7Fh)
170h Common RAM
(Accesses
70h – 7Fh)
1F0h Common RAM
(Accesses
70h – 7Fh)
270h Common RAM
(Accesses
70h – 7Fh)
2F0h Common RAM
(Accesses
70h – 7Fh)
370h Common RAM
(Accesses
70h – 7Fh)
3F0h Common RAM
(Accesses
70h – 7Fh)
07Fh 0FFh 17Fh 1FFh 27Fh 2FFh 37Fh 3FFh
Legend: = Unimplemented data memory locations, read as ‘0’.
PIC16(L)F1508/9
DS41609A-page 24 Preliminary 2011 Microchip Technology Inc.
TABLE 3-4: PIC16(L)F1509 MEMORY MAP, BANK 1-7
BANK 0 BANK 1 BANK 2 BANK 3 BANK 4 BANK 5 BANK 6 BANK 7
000h
Core Registers
(Table 3-2)
080h
Core Registers
(Table 3-2)
100h
Core Registers
(Table 3-2)
180h
Core Registers
(Table 3-2)
200h
Core Registers
(Table 3-2)
280h
Core Registers
(Table 3-2)
300h
Core Registers
(Table 3-2)
380h
Core Registers
(Table 3-2)
00Bh 08Bh 10Bh 18Bh 20Bh 28Bh 30Bh 38Bh
00Ch PORTA 08Ch TRISA 10Ch LATA 18Ch ANSELA 20Ch WPUA 28Ch — 30Ch — 38Ch —
00Dh PORTB 08Dh TRISB 10Dh LATB 18Dh ANSELB 20Dh WPUB 28Dh — 30Dh — 38Dh —
00Eh PORTC 08Eh TRISC 10Eh LATC 18Eh ANSELC 20Eh —28Eh—30Eh—38Eh—
00Fh —08Fh—10Fh—18Fh—20Fh—28Fh—30Fh—38Fh—
010h —090h—110h—190h—210h—290h—310h — 390h —
011h PIR1 091h PIE1 111h CM1CON0 191h PMADRL 211h SSP1BUF 291h —311h —391h IOCAP
012h PIR2 092h PIE2 112h CM1CON1 192h PMADRH 212h SSP1ADD 292h —312h —392h IOCAN
013h PIR3 093h PIE3 113h CM2CON0 193h PMDATL 213h SSP1MSK 293h —313h —393h IOCAF
014h —094h— 114h CM2CON1 194h PMDATH 214h SSP1STAT 294h —314h —394h IOCBP
015h TMR0 095h OPTION_REG 115h CMOUT 195h PMCON1 215h SSP1CON1 295h —315h —395h IOCBN
016h TMR1L 096h PCON 116h BORCON 196h PMCON2 216h SSP1CON2 296h — 316h — 396h IOCBF
017h TMR1H 097h WDTCON 117h FVRCON 197h VREGCON 217h SSP1CON3 297h — 317h — 397h —
018h T1CON 098h —118h
DACCON0 198h —218h—298h — 318h — 398h —
019h T1GCON 099h OSCCON 119h DACCON1 199h RCREG 219h —299h— 319h — 399h —
01Ah TMR2 09Ah OSCSTAT 11Ah —19Ah
TXREG 21Ah —29Ah—31Ah—39Ah—
01Bh PR2 09BhADRESL11Bh —19Bh
SPBRG 21Bh —29Bh—31Bh—39Bh —
01Ch T2CON 09Ch ADRESH 11Ch — 19Ch SPBRGH 21Ch — 29Ch — 31Ch —39Ch —
01Dh — 09Dh ADCON0 11Dh APFCON 19Dh RCSTA 21Dh —29Dh —31Dh —39Dh —
01Eh —09Eh ADCON1 11Eh —19Eh TXSTA 21Eh —29Eh —31Eh —39Eh —
01Fh —09Fh ADCON2 11Fh —19Fh
BAUDCON 21Fh —29Fh —31Fh —39Fh —
020h General
Purpose
Register
80 Bytes
0A0h
General
Purpose
Register
80 Bytes
120h General
Purpose
Register
80 Bytes
1A0h General
Purpose
Register
80 Bytes
220h General
Purpose
Register
80 Bytes
2A0h General
Purpose
Register
80 Bytes
320h General Purpose
Register
16Bytes 3A0h
Unimplemented
Read as ‘0’
Unimplemented
Read as ‘0’
0EFh
06Fh 16Fh 1EFh 26Fh 2EFh 36Fh 3EFh
070h
Common RAM
0F0h Common RAM
(Accesses
70h – 7Fh)
170h Common RAM
(Accesses
70h – 7Fh)
1F0h Common RAM
(Accesses
70h – 7Fh)
270h Common RAM
(Accesses
70h – 7Fh)
2F0h Common RAM
(Accesses
70h – 7Fh)
370h Common RAM
(Accesses
70h – 7Fh)
3F0h Common RAM
(Accesses
70h – 7Fh)
07Fh 0FFh 17Fh 1FFh 27Fh 2FFh 37Fh 3FFh
Legend: = Unimplemented data memory locations, read as ‘0’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 25
PIC16(L)F1508/9
TABLE 3-5: PIC16(L)F1508/9 MEMORY MAP, BANK 8-23
BANK 8 BANK 9 BANK 10 BANK 11 BANK 12 BANK 13 BANK 14 BANK 15
400h
40Bh
Core Registers
(Table 3-2)
480h
48Bh
Core Registers
(Table 3-2)
500h
50Bh
Core Registers
(Table 3-2)
580h
58Bh
Core Registers
(Table 3-2)
600h
60Bh
Core Registers
(Table 3-2)
680h
68Bh
Core Registers
(Table 3-2)
700h
70Bh
Core Registers
(Table 3-2)
780h
78Bh
Core Registers
(Table 3-2)
40Ch — 48Ch — 50Ch — 58Ch — 60Ch — 68Ch — 70Ch — 78Ch —
40Dh — 48Dh — 50Dh — 58Dh — 60Dh — 68Dh — 70Dh — 78Dh —
40Eh —48Eh—50Eh—58Eh—60Eh—68Eh—70Eh—78Eh—
40Fh —48Fh—50Fh—58Fh—60Fh—68Fh—70Fh—78Fh—
410h —490h—510h—590h—610h—690h— 710h — 790h —
411h —491h—511h—591h— 611h PWM1DCL 691h CWG1DBR 711h — 791h —
412h —492h—512h—592h— 612h PWM1DCH 692h CWG1DBF 712h — 792h —
413h —493h—513h—593h— 613h PWM1CON 693h CWG1CON0 713h — 793h —
414h —494h—514h—594h— 614h PWM2DCL 694h CWG1CON1 714h — 794h —
415h —495h—515h—595h— 615h PWM2DCH 695h CWG1CON2 715h — 795h —
416h —496h—516h—596h— 616h PWM2CON 696h — 716h — 796h —
417h —497h—517h—597h— 617h PWM3DCL 697h — 717h — 797h —
418h — 498h NCO1ACCL 518h —598h— 618h PWM3DCH 698h — 718h — 798h —
419h — 499h NCO1ACCH 519h —599h— 619h PWM3CON 699h — 719h — 799h —
41Ah — 49Ah NCO1ACCU 51Ah —59Ah— 61Ah PWM4DCL 69Ah —71Ah—79Ah—
41Bh — 49Bh NCO1INCL 51Bh —59Bh— 61Bh PWM4DCH 69Bh —71Bh—79Bh—
41Ch — 49Ch NCO1INCH 51Ch — 59Ch — 61Ch PWM4CON 69Ch — 71Ch — 79Ch —
41Dh — 49Dh — 51Dh — 59Dh — 61Dh — 69Dh — 71Dh — 79Dh —
41Eh — 49Eh NCO1CON 51Eh —59Eh—61Eh—69Eh—71Eh—79Eh—
41Fh — 49Fh NCO1CLK 51Fh —59Fh—61Fh—69Fh—71Fh—79Fh—
420h
Unimplemented
Read as ‘0’
4A0h
Unimplemented
Read as ‘0’
520h
Unimplemented
Read as ‘0’
5A0h
Unimplemented
Read as ‘0’
620h
Unimplemented
Read as ‘0’
6A0h
Unimplemented
Read as ‘0’
720h
Unimplemented
Read as ‘0’
7A0h
Unimplemented
Read as ‘0’
46Fh 4EFh 56Fh 5EFh 64Fh 6EFh 76Fh 7EFh
470h
Common RAM
(Accesses
70h – 7Fh)
4F0h
Common RAM
(Accesses
70h – 7Fh)
570h
Common RAM
(Accesses
70h – 7Fh)
5F0h
Common RAM
(Accesses
70h – 7Fh)
650h
Common RAM
(Accesses
70h – 7Fh)
6F0h
Common RAM
(Accesses
70h – 7Fh)
770h
Common RAM
(Accesses
70h – 7Fh)
7F0h
Common RAM
(Accesses
70h – 7Fh)
47Fh 4FFh 57Fh 5FFh 67Fh 6FFh 77Fh 7FFh
BANK 16 BANK 17 BANK 18 BANK 19 BANK 20 BANK 21 BANK 22 BANK 23
800h
80Bh
Core Registers
(Table 3-2 )
880h
88Bh
Core Registers
(Table 3-2)
900h
90Bh
Core Registers
(Table 3-2)
980h
98Bh
Core Registers
(Table 3-2)
A00h
A0Bh
Core Registers
(Table 3-2)
A80h
A8Bh
Core Registers
(Table 3-2)
B00h
B0Bh
Core Registers
(Table 3-2)
B80h
B8Bh
Core Registers
(Table 3-2)
80Ch
Unimplemented
Read as ‘0’
88Ch
Unimplemented
Read as ‘0’
90Ch
Unimplemented
Read as ‘0’
98Ch
Unimplemented
Read as ‘0’
A0Ch
Unimplemented
Read as ‘0’
A8Ch
Unimplemented
Read as ‘0’
B0Ch
Unimplemented
Read as ‘0’
B8Ch
Unimplemented
Read as ‘0’
86Fh 8EFh 96Fh 9EFh A6Fh AEFh B6Fh BEFh
870h Common RAM
(Accesses
70h – 7Fh)
8F0h Common RAM
(Accesses
70h – 7Fh)
970h Common RAM
(Accesses
70h – 7Fh)
9F0h Common RAM
(Accesses
70h – 7Fh)
A70h Common RAM
(Accesses
70h – 7Fh)
AF0h Common RAM
(Accesses
70h – 7Fh)
B70h Common RAM
(Accesses
70h – 7Fh)
BF0h Common RAM
(Accesses
70h – 7Fh)
87Fh 8FFh 97Fh 9FFh A7Fh AFFh B7Fh BFFh
Legend: = Unimplemented data memory locations, read as ‘0’.
PIC16(L)F1508/9
DS41609A-page 26 Preliminary 2011 Microchip Technology Inc.
TABLE 3-6: PIC16(L)F1508/9 MEMORY MAP, BANK 24-31
Legend: = Unimplemented data memory locations, read as ‘0’.
BANK 24 BANK 25 BANK 26 BANK 27 BANK 28 BANK 29 BANK 30 BANK 31
C00h
C0Bh
Core Registers
(Ta b l e 3 -2 )
C80h
C8Bh
Core Registers
(Ta b l e 3 -2 )
D00h
D0Bh
Core Registers
(Ta b l e 3 -2 )
D80h
D8Bh
Core Registers
(Ta b l e 3 -2 )
E00h
E0Bh
Core Registers
(Ta b l e 3 -2 )
E80h
E8Bh
Core Registers
(Ta b l e 3 -2 )
F00h
F0Bh
Core Registers
(Ta b l e 3 -2 )
F80h
F8Bh
Core Registers
(Ta b l e 3 -2 )
C0Ch —C8Ch—D0Ch—D8Ch—E0Ch—E8Ch—F0Ch
See Ta b le 3 - 7 for
register mapping
details
F8Ch
See Ta b le 3 - 7 for
register mapping
details
C0Dh —C8Dh—D0Dh—D8Dh—E0Dh—E8Dh— F0Dh F8Dh
C0Eh —C8Eh—D0Eh—D8Eh—E0Eh—E8Eh— F0Eh F8Eh
C0Fh —C8Fh—D0Fh—D8Fh—E0Fh—E8Fh— F0Fh F8Fh
C10h —C90h—D10h—D90h—E10h—E90h— F10h F90h
C11h —C91h—D11h—D91h—E11h—E91h— F11h F91h
C12h —C92h—D12h—D92h—E12h—E92h— F12h F92h
C13h —C93h—D13h—D93h—E13h—E93h— F13h F93h
C14h —C94h—D14h—D94h—E14h—E94h— F14h F94h
C15h —C95h—D15h—D95h—E15h—E95h— F15h F95h
C16h —C96h—D16h—D96h—E16h—E96h— F16h F96h
C17h —C97h—D17h—D97h—E17h—E97h— F17h F97h
C18h —C98h—D18h—D98h—E18h—E98h— F18h F98h
C19h —C99h—D19h—D99h—E19h—E99h— F19h F99h
C1Ah —C9Ah—D1Ah—D9Ah—E1Ah—E9Ah— F1Ah F9Ah
C1Bh —C9Bh—D1Bh—D9Bh—E1Bh—E9Bh— F1Bh F9Bh
C1Ch —C9Ch—D1Ch—D9Ch—E1Ch—E9Ch— F1Ch F9Ch
C1Dh —C9Dh—D1Dh—D9Dh—E1Dh—E9Dh— F1Dh F9Dh
C1Eh —C9Eh—D1Eh—D9Eh—E1Eh—E9Eh— F1Eh F9Eh
C1Fh —C9Fh—D1Fh—D9Fh—E1Fh—E9Fh— F1Fh F9Fh
C20h
Unimplemented
Read as ‘0’
CA0h
Unimplemented
Read as ‘0’
D20h
Unimplemented
Read as ‘0’
DA0h
Unimplemented
Read as ‘0’
E20h
Unimplemented
Read as ‘0’
EA0h
Unimplemented
Read as ‘0’
F20h FA0h
C6Fh CEFh D6Fh DEFh E6Fh EEFh F6Fh FEFh
C70h Common RAM
(Accesses
70h – 7Fh)
CF0h Common RAM
(Accesses
70h – 7Fh)
D70h Common RAM
(Accesses
70h – 7Fh)
DF0h Common RAM
(Accesses
70h – 7Fh)
E70h Common RAM
(Accesses
70h – 7Fh)
EF0h Common RAM
(Accesses
70h – 7Fh)
F70h Common RAM
(Accesses
70h – 7Fh)
FF0h Common RAM
(Accesses
70h – 7Fh)
CFFh CFFh D7Fh DFFh E7Fh EFFh F7Fh FFFh
2011 Microchip Technology Inc. Preliminary DS41609A-page 27
PIC16(L)F1508/9
TABLE 3-7: PIC16(L)F1508/9 MEMORY MAP, BANK 30-31
Bank 30
F0Ch —
F0Dh —
F0Eh —
F0Fh CLCDATA
F10h CLC1CON
F11h CLC1POL
F12h CLC1SEL0
F13h CLC1SEL1
F14h CLC1GLS0
F15h CLC1GLS1
F16h CLC1GLS2
F17h CLC1GLS3
F18h CLC2CON
F19h CLC2POL
F1Ah CLC2SEL0
F1Bh CLC2SEL1
F1Ch CLC2GLS0
F1Dh CLC2GLS1
F1Eh CLC2GLS2
F1Fh CLC2GLS3
F20h CLC3CON
F21h CLC3POL
F22h CLC3SEL0
F23h CLC3SEL1
F24h CLC3GLS0
F25h CLC3GLS1
F26h CLC3GLS2
F27h CLC3GLS3
F2Ah CLC4CON
F2Bh CLC4POL
F2Ch CLC4SEL0
F2Dh CLC4SEL1
F2Eh CLC4GLS0
F2Fh CLC4GLS1
F31h CLC4GLS2
F31h CLC4GLS3
F32h Unimplemented
Read as ‘0’
F6Fh
Bank 31
F8Ch
FE3h
Unimplemented
Read as ‘0’
FE4h STATUS_SHAD
FE5h WREG_SHAD
FE6h BSR_SHAD
FE7h PCLATH_SHAD
FE8h FSR0L_SHAD
FE9h FSR0H_SHAD
FEAh FSR1L_SHAD
FEBh FSR1H_SHAD
FECh —
FEDh STKPTR
FEEh TOSL
FEFh TOSH
Legend: = Unimplemented data memory locations, read as ‘0’.
PIC16(L)F1508/9
DS41609A-page 28 Preliminary 2011 Microchip Technology Inc.
3.2.6 CORE FUNCTION REGISTERS
SUMMARY
The Core Function registers listed in Table 3 -8 can be
addressed from any Bank.
TABLE 3-8: CORE FUNCTION REGISTERS SUMMARY
Addr Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Value on all
other Resets
Bank 0-31
x00h or
x80h INDF0 Addressing this location uses contents of FSR0H/FSR0L to address data memory
(not a physical register) xxxx xxxx uuuu uuuu
x01h or
x81h INDF1 Addressing this location uses contents of FSR1H/FSR1L to address data memory
(not a physical register) xxxx xxxx uuuu uuuu
x02h or
x82h PCL Program Counter (PC) Least Significant Byte 0000 0000 0000 0000
x03h or
x83h STATUS — — —TOPD ZDCC---1 1000 ---q quuu
x04h or
x84h FSR0L Indirect Data Memory Address 0 Low Pointer 0000 0000 uuuu uuuu
x05h or
x85h FSR0H Indirect Data Memory Address 0 High Pointer 0000 0000 0000 0000
x06h or
x86h FSR1L Indirect Data Memory Address 1 Low Pointer 0000 0000 uuuu uuuu
x07h or
x87h FSR1H Indirect Data Memory Address 1 High Pointer 0000 0000 0000 0000
x08h or
x88h BSR — — —BSR<4:0>---0 0000 ---0 0000
x09h or
x89h WREG Working Register 0000 0000 uuuu uuuu
x0Ah or
x8Ah PCLATH — Write Buffer for the upper 7 bits of the Program Counter -000 0000 -000 0000
x0Bh or
x8Bh INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 0000 0000 0000 0000
Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ‘0’, r = reserved.
Shaded locations are unimplemented, read as ‘0’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 29
PIC16(L)F1508/9
TABLE 3-9: SPECIAL FUNCTION REGISTER SUMMARY
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Value on all
other
Resets
Bank 0
00Ch PORTA —— RA5 RA4 RA3 RA2 RA1 RA0 --xx xxxx --xx xxxx
00Dh PORTB RB7 RB6 RB5 RB4 — — — — xxxx ---- xxxx ----
00Eh PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 xxxx xxxx xxxx xxxx
00Fh —Unimplemented — —
010h —Unimplemented — —
011h PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF — TMR2IF TMR1IF 0000 0-00 0000 0-00
012h PIR2 OSFIF C2IF C1IF — BCL1IF NCO1IF — — 000- -0-- 000- -0--
013h PIR3 — — — — CLC4IF CLC3IF CLC2IF CLC1IF ---- 0000 ---- 0000
014h —Unimplemented — —
015h TMR0 Holding Register for the 8-bit Timer0 Count xxxx xxxx uuuu uuuu
016h TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Count xxxx xxxx uuuu uuuu
017h TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Count xxxx xxxx uuuu uuuu
018h T1CON TMR1CS<1:0> T1CKPS<1:0> T1OSCEN T1SYNC —TMR1ON0000 00-0 uuuu uu-u
019h T1GCON TMR1GE T1GPOL T1GTM T1GSPM T1GGO/
DONE
T1GVAL T1GSS<1:0> 0000 0x00 uuuu uxuu
01Ah TMR2 Timer2 Module Register 0000 0000 0000 0000
01Bh PR2 Timer2 Period Register 1111 1111 1111 1111
01Ch T2CON — T2OUTPS<3:0> TMR2ON T2CKPS<1:0> -000 0000 -000 0000
01Dh —Unimplemented — —
01Eh —Unimplemented — —
01Fh —Unimplemented — —
Bank 1
08Ch TRISA —— TRISA5 TRISA4 —(2) TRISA2 TRISA1 TRISA0 --11 1111 --11 1111
08Dh TRISB TRISB7 TRISB6 TRISB5 TRISB4 — — — — 1111 ---- 1111 ----
08Eh TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 1111 1111 1111 1111
08Fh —Unimplemented — —
090h —Unimplemented — —
091h PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE — TMR2IE TMR1IE 0000 0-00 0000 0-00
092h PIE2 OSFIE C2IE C1IE — BCL1IE NCO1IE — — 000- 00-- 000- 00--
093h PIE3 — — — — CLC4IE CLC3IE CLC2IE CLC1IE ---- 0000 ---- 0000
094h —Unimplemented — —
095h
OPTION_REG
WPUEN INTEDG TMR0CS TMR0SE PSA PS<2:0> 1111 1111 1111 1111
096h PCON STKOVF STKUNF —RWDT RMCLR RI POR BOR 00-1 11qq qq-q qquu
097h WDTCON —— WDTPS<4:0> SWDTEN --01 0110 --01 0110
098h —Unimplemented — —
099h OSCCON — IRCF<3:0> —SCS<1:0>-011 1-00 -011 1-00
09Ah OSCSTAT SOSCR —OSTSHFIOFR—— LFIOFR HFIOFS 0-q0 --00 q-qq --qq
09Bh ADRESL xxxx xxxx uuuu uuuu
09Ch ADRESH A/D Result Register High xxxx xxxx uuuu uuuu
09Dh ADCON0 — CHS<4:0>
GO/DONE
ADON -000 0000 -000 0000
09Eh ADCON1 ADFM ADCS<2:0> — —
ADPREF<1:0>
0000 --00 0000 --00
09Fh ADCON2 TRIGSEL<3:0> — — — — 0000 ---- 0000 ----
Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, r = reserved. Shaded locations are unimplemented, read as ‘0’.
Note 1: PIC16F1508/9 only.
2: Unimplemented, read as ‘1’.
PIC16(L)F1508/9
DS41609A-page 30 Preliminary 2011 Microchip Technology Inc.
Bank 2
10Ch LATA ——LATA5LATA4— LATA2 LATA1 LATA0 --xx -xxx --uu -uuu
10Dh LATB LATB7 LATB6 LATB5 LATB4 — — — — xxxx ---- uuuu ----
10Eh LATC LATC7 LATC6 LATC5 LATC4 LATC3 LATC2 LATC1 LATC0 xxxx xxxx uuuu uuuu
10Fh —Unimplemented — —
110h —Unimplemented — —
111h CM1CON0 C1ON C1OUT C1OE C1POL — C1SP C1HYS C1SYNC 0000 -100 0000 -100
112h CM1CON1 C1INTP C1INTN C1PCH<1:0> — C1NCH<2:0> 0000 -000 0000 -000
113h CM2CON0 C2ON C2OUT C2OE C2POL — C2SP C2HYS C2SYNC 0000 -100 0000 -100
114h CM2CON1 C2INTP C2INTN C2PCH<1:0> — C2NCH<2:0> 0000 -000 0000 -000
115h CMOUT ——————MC2OUT MC1OUT---- --00 ---- --00
116h BORCON SBOREN BORFS ———— — BORRDY 10-- ---q uu-- ---u
117h FVRCON FVREN FVRRDY TSEN TSRNG CDAFVR<1:0> ADFVR<1:0> 0q00 0000 0q00 0000
118h DACCON0 DACEN — DACOE1 DACOE2 — DACPSS — — 0-00 -0-- 0-00 -0--
119h DACCON1 —— DACR<4:0> ---0 0000 ---0 0000
11Ah
to
11Ch
—Unimplemented — —
11Dh APFCON — — — SSSEL T1GSEL — CLC1SEL NCO1SEL ---0 0-00 ---0 0-00
11Eh —Unimplemented — —
11Fh —Unimplemented — —
Bank 3
18Ch ANSELA — — — ANSA4 — ANSA2 ANSA1 ANSA0 ---1 -111 ---1 -111
18Dh ANSELB —— ANSB5 ANSB4 — — — — --11 ---- --11 ----
18Eh ANSELC ANSC7 ANSC6 —— ANSC3 ANSC2 ANSC1 ANSC0 11-- 1111 11-- 1111
18Fh —Unimplemented — —
190h —Unimplemented — —
191h PMADRL Flash Program Memory Address Register Low Byte 0000 0000 0000 0000
192h PMADRH — Flash Program Memory Address Register High Byte -000 0000 -000 0000
193h PMDATL Flash Program Memory Read Data Register Low Byte xxxx xxxx uuuu uuuu
194h PMDATH —— Flash Program Memory Read Data Register High Byte --xx xxxx --uu uuuu
195h PMCON1 —(2) CFGS LWLO FREE WRERR WREN WR RD 0000 x000 0000 q000
196h PMCON2 Flash Program Memory Control Register 2 0000 0000 0000 0000
197h VREGCON(1) ——————VREGPMReserved ---- --01 ---- --01
198h —Unimplemented — —
199h RCREG USART Receive Data Register 0000 0000 0000 0000
19Ah TXREG USART Transmit Data Register 0000 0000 0000 0000
19Bh SPBRGL Baud Rate Generator Data Register Low 0000 0000 0000 0000
19Ch SPBRGH Baud Rate Generator Data Register High 0000 0000 0000 0000
19Dh RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x
19Eh TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 0000 0010
19Fh BAUDCON ABDOVF RCIDL — SCKP BRG16 — WUE ABDEN 01-0 0-00 01-0 0-00
TABLE 3-9: SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Value on all
other
Resets
Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, r = reserved. Shaded locations are unimplemented, read as ‘0’.
Note 1: PIC16F1508/9 only.
2: Unimplemented, read as ‘1’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 31
PIC16(L)F1508/9
Bank 4
20Ch WPUA —— WPUA5 WPUA4 WPUA3 WPUA2 WPUA1 WPUA0 --11 1111 --11 1111
20Dh WPUB WPUB7 WPUB6 WPUB5 WPUB4 — — — — 1111 ---- 1111 ----
20Eh
to
210h
—Unimplemented — —
211h SSP1BUF Synchronous Serial Port Receive Buffer/Transmit Register xxxx xxxx uuuu uuuu
212h SSP1ADD ADD<7:0> 0000 0000 0000 0000
213h SSP1MSK MSK<7:0> 1111 1111 1111 1111
214h SSP1STAT SMP CKE D/A PSR/WUA BF 0000 0000 0000 0000
215h SSP1CON1 WCOL SSPOV SSPEN CKP SSPM<3:0> 0000 0000 0000 0000
216h SSP1CON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 0000 0000 0000 0000
217h SSP1CON3 ACKTIM PCIE SCIE BOEN SDAHT SBCDE AHEN DHEN 0000 0000 0000 0000
218h
to
21Fh
—Unimplemented — —
Bank 5
28Ch
to
29Fh
—Unimplemented — —
Bank 6
30Ch
to
31Fh
—Unimplemented — —
Bank 7
38Ch
to
390h
—Unimplemented — —
391h IOCAP —— IOCAP5 IOCAP4 IOCAP3
IOCAP2 IOCAP1 IOCAP0
--00 0000 --00 0000
392h IOCAN — — IOCAN5 IOCAN4 IOCAN3
IOCAN2 IOCAN1 IOCAN0
--00 0000 --00 0000
393h IOCAF —— IOCAF5 IOCAF4 IOCAF3
IOCAF2 IOCAF1 IOCAF0
--00 0000 --00 0000
394h IOCBP IOCBP7 IOCBP6 IOCBP5 IOCBP4 — — — — 0000 ---- 0000 ----
395h IOCBN IOCBN7 IOCBN6 IOCBN5 IOCBN4 — — — — 0000 ---- 0000 ----
396h IOCBF IOCBF7 IOCBF6 IOCBF5 IOCBF4 — — — — 0000 ---- 0000 ----
397h
to
39Fh
—Unimplemented — —
Bank 8
40Ch
to
41Fh
—Unimplemented — —
Bank 9
48Ch
to
497h
—Unimplemented — —
498h NCO1ACCL NCO1ACC<7:0> 0000 0000 0000 0000
499h NCO1ACCH NCO1ACC<15:8> 0000 0000 0000 0000
49Ah NCO1ACCU NCO1ACC<19:16> 0000 0000 0000 0000
49Bh NCO1INCL NCO1INC<7:0> 0000 0000 0000 0000
49Ch NCO1INCH NCO1INC<15:8> 0000 0000 0000 0000
49Dh —Unimplemented — —
49Eh NCO1CON N1EN N1OE N1OUT N1POL — — —N1PFM0000 ---0 0000 ---0
49Fh NCO1CLK N1PWS<2:0> ———N1CKS<1:0>0000 --00 0000 --00
TABLE 3-9: SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Value on all
other
Resets
Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, r = reserved. Shaded locations are unimplemented, read as ‘0’.
Note 1: PIC16F1508/9 only.
2: Unimplemented, read as ‘1’.
PIC16(L)F1508/9
DS41609A-page 32 Preliminary 2011 Microchip Technology Inc.
Bank 10
50Ch
to
51Fh
—Unimplemented — —
Bank 11
58Ch
to
59Fh
—Unimplemented — —
Bank 12
60Ch
to
610h
—Unimplemented — —
611h PWM1DCL PWM1DCL<7:6> — — — — — — 00-- ---- 00-- ----
612h PWM1DCH PWM1DCH<7:0> xxxx xxxx uuuu uuuu
613h PWM1CON0 PWM1EN PWM1OE PWM1OUT PWM1POL — — — — 0000 ---- 0000 ----
614h PWM2DCL PWM2DCL<7:6> — — — — — — 00-- ---- 00-- ----
615h PWM2DCH PWM2DCH<7:0> xxxx xxxx uuuu uuuu
616h PWM2CON0 PWM2EN PWM2OE PWM2OUT PWM2POL — — — — 0000 ---- 0000 ----
617h PWM3DCL PWM3DCL<7:6> — — — — — — 00-- ---- 00-- ----
618h PWM3DCH PWM3DCH<7:0> xxxx xxxx uuuu uuuu
619h PWM3CON0 PWM3EN PWM3OE PWM3OUT PWM3POL — — — — 0000 ---- 0000 ----
61Ah PWM4DCL PWM4DCL<7:6> — — — — — — 00-- ---- 00-- ----
61Bh PWM4DCH PWM4DCH<7:0> xxxx xxxx uuuu uuuu
61Ch PWM4CON0 PWM4EN PWM4OE PWM4OUT PWM4POL — — — — 0000 ---- 0000 ----
61Dh
to
61Fh
—Unimplemented — —
Bank 13
68Ch
to
690h
—Unimplemented — —
691h CWG1DBR ——CWG1DBR<5:0>--00 0000 --00 0000
692h CWG1DBF ——CWG1DBF<5:0>--xx xxxx --xx xxxx
693h CWG1CON0 G1EN G1OEB G1OEA G1POLB G1POLA ——G1CS00000 0--0 0000 0--0
694h CWG1CON1 G1ASDLB<1:0> G1ASDLA<1:0> — G1IS<2:0> 0000 -000 0000 -000
695h CWG1CON2 G1ASE G1ARSEN —— G1ASDC2 G1ASDC1 G1ASDSFLT G1ASDSCLC2 00-- --00 00-- --00
696h
to
69Fh
—Unimplemented — —
TABLE 3-9: SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Value on all
other
Resets
Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, r = reserved. Shaded locations are unimplemented, read as ‘0’.
Note 1: PIC16F1508/9 only.
2: Unimplemented, read as ‘1’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 33
PIC16(L)F1508/9
Banks 14-29
x0Ch/
x8Ch
—
x1Fh/
x9Fh
—Unimplemented — —
Bank 30
F0Ch
to
F0Eh
—Unimplemented — —
F0Fh CLCDATA — — — — MLC4OUT MLC3OUT MLC2OUT MLC1OUT ---- 0000 ---- 0000
F10h CLC1CON LC1EN LC1OE LC1OUT LC1INTP LC1INTN LC1MODE<2:0> 0000 0000 0000 0000
F11h CLC1POL LC1POL — — — LC1G4POL LC1G3POL LC1G2POL LC1G1POL 0--- xxxx 0--- uuuu
F12h CLC1SEL0 — LC1D2S<2:0> — LC1D1S<2:0> -xxx -xxx -uuu -uuu
F13h CLC1SEL1 — LC1D4S<2:0> — LC1D3S<2:0> -xxx -xxx -uuu -uuu
F14h CLC1GLS0 LC1G1D4T LC1G1D4N LC1G1D3T LC1G1D3N LC1G1D2T LC1G1D2N LC1G1D1T LC1G1D1N xxxx xxxx uuuu uuuu
F15h CLC1GLS1 LC1G2D4T LC1G2D4N LC1G2D3T LC1G2D3N LC1G2D2T LC1G2D2N LC1G2D1T LC1G2D1N xxxx xxxx uuuu uuuu
F16h CLC1GLS2 LC1G3D4T LC1G3D4N LC1G3D3T LC1G3D3N LC1G3D2T LC1G3D2N LC1G3D1T LC1G3D1N xxxx xxxx uuuu uuuu
F17h CLC1GLS3 LC1G4D4T LC1G4D4N LC1G4D3T LC1G4D3N LC1G4D2T LC1G4D2N LC1G4D1T LC1G4D1N xxxx xxxx uuuu uuuu
F18h CLC2CON LC2EN LC2OE LC2OUT LC2INTP LC2INTN LC2MODE<2:0> 0000 0000 0000 0000
F19h CLC2POL LC2POL — — — LC2G4POL LC2G3POL LC2G2POL LC2G1POL 0--- xxxx 0--- uuuu
F1Ah CLC2SEL0 — LC2D2S<2:0> — LC2D1S<2:0> -xxx -xxx -uuu -uuu
F1Bh CLC2SEL1 — LC2D4S<2:0> — LC2D3S<2:0> -xxx -xxx -uuu -uuu
F1Ch CLC2GLS0 LC2G1D4T LC2G1D4N LC2G1D3T LC2G1D3N LC2G1D2T LC2G1D2N LC2G1D1T LC2G1D1N xxxx xxxx uuuu uuuu
F1Dh CLC2GLS1 LC2G2D4T LC2G2D4N LC2G2D3T LC2G2D3N LC2G2D2T LC2G2D2N LC2G2D1T LC2G2D1N xxxx xxxx uuuu uuuu
F1Eh CLC2GLS2 LC2G3D4T LC2G3D4N LC2G3D3T LC2G3D3N LC2G3D2T LC2G3D2N LC2G3D1T LC2G3D1N xxxx xxxx uuuu uuuu
F1Fh CLC2GLS3 LC2G4D4T LC2G4D4N LC2G4D3T LC2G4D3N LC2G4D2T LC2G4D2N LC2G4D1T LC2G4D1N xxxx xxxx uuuu uuuu
F20h CLC3CON LC3EN LC3OE LC3OUT LC3INTP LC3INTN LC3MODE<2:0> 0000 0000 0000 0000
F21h CLC3POL LC3POL — — — LC3G4POL LC3G3POL LC3G2POL LC3G1POL 0--- xxxx 0--- uuuu
F22h CLC3SEL0 — LC3D2S<2:0> — LC3D1S<2:0> -xxx -xxx -uuu -uuu
F23h CLC3SEL1 — LC3D4S<2:0> — LC3D3S<2:0> -xxx -xxx -uuu -uuu
F24h CLC3GLS0 LC3G1D4T LC3G1D4N LC3G1D3T LC3G1D3N LC3G1D2T LC3G1D2N LC3G1D1T LC3G1D1N xxxx xxxx uuuu uuuu
F25h CLC3GLS1 LC3G2D4T LC3G2D4N LC3G2D3T LC3G2D3N LC3G2D2T LC3G2D2N LC3G2D1T LC3G2D1N xxxx xxxx uuuu uuuu
F26h CLC3GLS2 LC3G3D4T LC3G3D4N LC3G3D3T LC3G3D3N LC3G3D2T LC3G3D2N LC3G3D1T LC3G3D1N xxxx xxxx uuuu uuuu
F27h CLC3GLS3 LC3G4D4T LC3G4D4N LC3G4D3T LC3G4D3N LC3G4D2T LC3G4D2N LC3G4D1T LC3G4D1N xxxx xxxx uuuu uuuu
F28h CLC4CON LC4EN LC4OE LC4OUT LC4INTP LC4INTN LC4MODE<2:0> 0000 0000 0000 0000
F29h CLC4POL LC4POL — — — LC4G4POL LC4G3POL LC4G2POL LC4G1POL 0--- xxxx 0--- uuuu
F2Ah CLC4SEL0 — LC4D2S<2:0> — LC4D1S<2:0> -xxx -xxx -uuu -uuu
F2Bh CLC4SEL1 — LC4D4S<2:0> — LC4D3S<2:0> -xxx -xxx -uuu -uuu
F2Ch CLC4GLS0 LC4G1D4T LC4G1D4N LC4G1D3T LC4G1D3N LC4G1D2T LC4G1D2N LC4G1D1T LC4G1D1N xxxx xxxx uuuu uuuu
F2Dh CLC4GLS1 LC4G2D4T LC4G2D4N LC4G2D3T LC4G2D3N LC4G2D2T LC4G2D2N LC4G2D1T LC4G2D1N xxxx xxxx uuuu uuuu
F2Eh CLC4GLS2 LC4G3D4T LC4G3D4N LC4G3D3T LC4G3D3N LC4G3D2T LC4G3D2N LC4G3D1T LC4G3D1N xxxx xxxx uuuu uuuu
F2Fh CLC4GLS3 LC4G4D4T LC4G4D4N LC4G4D3T LC4G4D3N LC4G4D2T LC4G4D2N LC4G4D1T LC4G4D1N xxxx xxxx uuuu uuuu
F30h
to
F6Fh
—Unimplemented — —
TABLE 3-9: SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Value on all
other
Resets
Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, r = reserved. Shaded locations are unimplemented, read as ‘0’.
Note 1: PIC16F1508/9 only.
2: Unimplemented, read as ‘1’.
PIC16(L)F1508/9
DS41609A-page 34 Preliminary 2011 Microchip Technology Inc.
Bank 31
F8Ch
—
FE3h
—Unimplemented — —
FE4h STATUS_
SHAD
— — — — — Z_SHAD DC_SHAD C_SHAD ---- -xxx ---- -uuu
FE5h WREG_
SHAD
Working Register Shadow xxxx xxxx uuuu uuuu
FE6h BSR_
SHAD
— — — Bank Select Register Shadow ---x xxxx ---u uuuu
FE7h PCLATH_
SHAD
— Program Counter Latch High Register Shadow -xxx xxxx uuuu uuuu
FE8h FSR0L_
SHAD
Indirect Data Memory Address 0 Low Pointer Shadow xxxx xxxx uuuu uuuu
FE9h FSR0H_
SHAD
Indirect Data Memory Address 0 High Pointer Shadow xxxx xxxx uuuu uuuu
FEAh FSR1L_
SHAD
Indirect Data Memory Address 1 Low Pointer Shadow xxxx xxxx uuuu uuuu
FEBh FSR1H_
SHAD
Indirect Data Memory Address 1 High Pointer Shadow xxxx xxxx uuuu uuuu
FECh —Unimplemented — —
FEDh STKPTR — — — Current Stack Pointer ---1 1111 ---1 1111
FEEh TOSL Top-of-Stack Low byte xxxx xxxx uuuu uuuu
FEFh TOSH — Top-of-Stack High byte -xxx xxxx -uuu uuuu
TABLE 3-9: SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED)
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR
Value on all
other
Resets
Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, r = reserved. Shaded locations are unimplemented, read as ‘0’.
Note 1: PIC16F1508/9 only.
2: Unimplemented, read as ‘1’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 35
PIC16(L)F1508/9
3.3 PCL and PCLATH
The Program Counter (PC) is 15 bits wide. The low byte
comes from the PCL register, which is a readable and
writable register. The high byte (PC<14:8>) is not directly
readable or writable and comes from PCLATH. On any
Reset, the PC is cleared. Figure 3-4 shows the five
situations for the loading of the PC.
FIGURE 3-4: LOADING OF PC IN
DIFFERENT SITUATIONS
3.3.1 MODIFYING PCL
Executing any instruction with the PCL register as the
destination simultaneously causes the Program Coun-
ter PC<14:8> bits (PCH) to be replaced by the contents
of the PCLATH register. This allows the entire contents
of the program counter to be changed by writing the
desired upper 7 bits to the PCLATH register. When the
lower 8 bits are written to the PCL register, all 15 bits of
the program counter will change to the values con-
tained in the PCLATH register and those being written
to the PCL register.
3.3.2 COMPUTED GOTO
A computed GOTO is accomplished by adding an offset to
the program counter (ADDWF PCL). When performing a
table read using a computed GOTO method, care should
be exercised if the table location crosses a PCL memory
boundary (each 256-byte block). Refer to Application
Note AN556, “Implementing a Table Read” (DS00556).
3.3.3 COMPUTED FUNCTION CALLS
A computed function CALL allows programs to maintain
tables of functions and provide another way to execute
state machines or look-up tables. When performing a
table read using a computed function CALL, care
should be exercised if the table location crosses a PCL
memory boundary (each 256-byte block).
If using the CALL instruction, the PCH<2:0> and PCL
registers are loaded with the operand of the CALL
instruction. PCH<6:3> is loaded with PCLATH<6:3>.
The CALLW instruction enables computed calls by com-
bining PCLATH and W to form the destination address.
A computed CALLW is accomplished by loading the W
register with the desired address and executing CALLW.
The PCL register is loaded with the value of W and
PCH is loaded with PCLATH.
3.3.4 BRANCHING
The branching instructions add an offset to the PC.
This allows relocatable code and code that crosses
page boundaries. There are two forms of branching,
BRW and BRA. The PC will have incremented to fetch
the next instruction in both cases. When using either
branching instruction, a PCL memory boundary may be
crossed.
If using BRW, load the W register with the desired
unsigned address and execute BRW. The entire PC will
be loaded with the address PC + 1 + W.
If using BRA, the entire PC will be loaded with PC + 1 +,
the signed value of the operand of the BRA instruction.
PCL
PCH 0
14
PC
PCL
PCH 0
14
PC
ALU Result
8
7
6
PCLATH
0
Instruction with
PCL as
Destination
GOTO, CALL
OPCODE <10:0>
11
4
6
PCLATH
0
PCL
PCH 0
14
PC
W
8
7
6
PCLATH
0
CALLW
PCL
PCH 0
14
PC
PC + W
15
BRW
PCLPCH 0
14
PC
PC + OPCODE <8:0>
15
BRA
PIC16(L)F1508/9
DS41609A-page 36 Preliminary 2011 Microchip Technology Inc.
3.4 Stack
All devices have a 16-level x 15-bit wide hardware
stack (refer to Figures 3-5 through 3-8). The stack
space is not part of either program or data space. The
PC is PUSHed onto the stack when CALL or CALLW
instructions are executed or an interrupt causes a
branch. The stack is POPed in the event of a RETURN,
RETLW or a RETFIE instruction execution. PCLATH is
not affected by a PUSH or POP operation.
The stack operates as a circular buffer if the STVREN
bit is programmed to ‘0‘ (Configuration Words). This
means that after the stack has been PUSHed sixteen
times, the seventeenth PUSH overwrites the value that
was stored from the first PUSH. The eighteenth PUSH
overwrites the second PUSH (and so on). The
STKOVF and STKUNF flag bits will be set on an Over-
flow/Underflow, regardless of whether the Reset is
enabled.
3.4.1 ACCESSING THE STACK
The stack is available through the TOSH, TOSL and
STKPTR registers. STKPTR is the current value of the
Stack Pointer. TOSH:TOSL register pair points to the
TOP of the stack. Both registers are read/writable. TOS
is split into TOSH and TOSL due to the 15-bit size of the
PC. To access the stack, adjust the value of STKPTR,
which will position TOSH:TOSL, then read/write to
TOSH:TOSL. STKPTR is 5 bits to allow detection of
overflow and underflow.
During normal program operation, CALL, CALLW and
Interrupts will increment STKPTR while RETLW,
RETURN, and RETFIE will decrement STKPTR. At any
time STKPTR can be inspected to see how much stack
is left. The STKPTR always points at the currently used
place on the stack. Therefore, a CALL or CALLW will
increment the STKPTR and then write the PC, and a
return will unload the PC and then decrement the
STKPTR.
Reference Figure 3-5 through Figure 3-8 for examples
of accessing the stack.
FIGURE 3-5: ACCESSING THE STACK EXAMPLE 1
Note 1: There are no instructions/mnemonics
called PUSH or POP. These are actions
that occur from the execution of the
CALL, CALLW, RETURN, RETLW and
RETFIE instructions or the vectoring to
an interrupt address.
Note: Care should be taken when modifying the
STKPTR while interrupts are enabled.
0x0F
0x0E
0x0D
0x0C
0x0B
0x0A
0x09
0x08
0x07
0x06
0x05
0x04
0x03
0x02
0x01
0x00
0x0000
STKPTR = 0x1F
Initial Stack Configuration:
After Reset, the stack is empty. The
empty stack is initialized so the Stack
Pointer is pointing at 0x1F. If the Stack
Overflow/Underflow Reset is enabled, the
TOSH/TOSL registers will return ‘0’. If
the Stack Overflow/Underflow Reset is
disabled, the TOSH/TOSL registers will
return the contents of stack address 0x0F.
0x1F STKPTR = 0x1F
Stack Reset Disabled
(STVREN = 0)
Stack Reset Enabled
(STVREN = 1)
TOSH:TOSL
TOSH:TOSL
2011 Microchip Technology Inc. Preliminary DS41609A-page 37
PIC16(L)F1508/9
FIGURE 3-6: ACCESSING THE STACK EXAMPLE 2
FIGURE 3-7: ACCESSING THE STACK EXAMPLE 3
0x0F
0x0E
0x0D
0x0C
0x0B
0x0A
0x09
0x08
0x07
Return Address0x06
Return Address0x05
Return Address0x04
Return Address0x03
Return Address0x02
Return Address0x01
Return Address0x00
STKPTR = 0x06
After seven CALLs or six CALLs and an
interrupt, the stack looks like the figure
on the left. A series of RETURN instructions
will repeatedly place the return addresses
into the Program Counter and pop the stack.
TOSH:TOSL
PIC16(L)F1508/9
DS41609A-page 38 Preliminary 2011 Microchip Technology Inc.
FIGURE 3-8: ACCESSING THE STACK EXAMPLE 4
3.4.2 OVERFLOW/UNDERFLOW RESET
If the STVREN bit in Configuration Words is
programmed to ‘1’, the device will be reset if the stack
is PUSHed beyond the sixteenth level or POPed
beyond the first level, setting the appropriate bits
(STKOVF or STKUNF, respectively) in the PCON
register.
3.5 Indirect Addressing
The INDFn registers are not physical registers. Any
instruction that accesses an INDFn register actually
accesses the register at the address specified by the
File Select Registers (FSR). If the FSRn address
specifies one of the two INDFn registers, the read will
return ‘0’ and the write will not occur (though Status bits
may be affected). The FSRn register value is created
by the pair FSRnH and FSRnL.
The FSR registers form a 16-bit address that allows an
addressing space with 65536 locations. These locations
are divided into three memory regions:
• Traditional Data Memory
• Linear Data Memory
• Program Flash Memory
0x0F
0x0E
0x0D
0x0C
0x0B
0x0A
0x09
0x08
0x07
0x06
0x05
0x04
0x03
0x02
0x01
Return Address0x00 STKPTR = 0x10
When the stack is full, the next CALL or
an interrupt will set the Stack Pointer to
0x10. This is identical to address 0x00
so the stack will wrap and overwrite the
return address at 0x00. If the Stack
Overflow/Underflow Reset is enabled, a
Reset will occur and location 0x00 will
not be overwritten.
Return Address
Return Address
Return Address
Return Address
Return Address
Return Address
Return Address
Return Address
Return Address
Return Address
Return Address
Return Address
Return Address
Return Address
Return Address
TOSH:TOSL
2011 Microchip Technology Inc. Preliminary DS41609A-page 39
PIC16(L)F1508/9
FIGURE 3-9: INDIRECT ADDRESSING
0x0000
0x0FFF
Traditional
FSR
Address
Range
Data Memory
0x1000 Reserved
Linear
Data Memory
Reserved
0x2000
0x29AF
0x29B0
0x7FFF
0x8000
0xFFFF
0x0000
0x0FFF
0x0000
0x7FFF
Program
Flash Memory
Note: Not all memory regions are completely implemented. Consult device memory tables for memory limits.
0x1FFF
PIC16(L)F1508/9
DS41609A-page 40 Preliminary 2011 Microchip Technology Inc.
3.5.1 TRADITIONAL DATA MEMORY
The traditional data memory is a region from FSR
address 0x000 to FSR address 0xFFF. The addresses
correspond to the absolute addresses of all SFR, GPR
and common registers.
FIGURE 3-10: TRADITIONAL DATA MEMORY MAP
Indirect AddressingDirect Addressing
Bank Select Location Select
4BSR 6 0
From Opcode FSRxL70
Bank Select Location Select
00000 00001 00010 11111
0x00
0x7F
Bank 0 Bank 1 Bank 2 Bank 31
0FSRxH70
0000
2011 Microchip Technology Inc. Preliminary DS41609A-page 41
PIC16(L)F1508/9
3.5.2 LINEAR DATA MEMORY
The linear data memory is the region from FSR
address 0x2000 to FSR address 0x29AF. This region is
a virtual region that points back to the 80-byte blocks of
GPR memory in all the banks.
Unimplemented memory reads as 0x00. Use of the
linear data memory region allows buffers to be larger
than 80 bytes because incrementing the FSR beyond
one bank will go directly to the GPR memory of the next
bank.
The 16 bytes of common memory are not included in
the linear data memory region.
FIGURE 3-11: LINEAR DATA MEMORY
MAP
3.5.3 PROGRAM FLASH MEMORY
To make constant data access easier, the entire
program Flash memory is mapped to the upper half of
the FSR address space. When the MSB of FSRnH is
set, the lower 15 bits are the address in program
memory which will be accessed through INDF. Only the
lower 8 bits of each memory location is accessible via
INDF. Writing to the program Flash memory cannot be
accomplished via the FSR/INDF interface. All
instructions that access program Flash memory via the
FSR/INDF interface will require one additional
instruction cycle to complete.
FIGURE 3-12: PROGRAM FLASH
MEMORY MAP
7
01
7
00
Location Select 0x2000
FSRnH FSRnL
0x020
Bank 0
0x06F
0x0A0
Bank 1
0x0EF
0x120
Bank 2
0x16F
0xF20
Bank 30
0xF6F
0x29AF
0
7
1
7
00
Location Select 0x8000
FSRnH FSRnL
0x0000
0x7FFF
0xFFFF
Program
Flash
Memory
(low 8
bits)
PIC16(L)F1508/9
DS41609A-page 42 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 43
PIC16(L)F1508/9
4.0 DEVICE CONFIGURATION
Device configuration consists of Configuration Words,
Code Protection and Device ID.
4.1 Configuration Words
There are several Configuration Word bits that allow
different oscillator and memory protection options.
These are implemented as Configuration Word 1 at
8007h and Configuration Word 2 at 8008h.
Note: The DEBUG bit in Configuration Words is
managed automatically by device
development tools including debuggers
and programmers. For normal device
operation, this bit should be maintained as
a '1'.
PIC16(L)F1508/9
DS41609A-page 44 Preliminary 2011 Microchip Technology Inc.
REGISTER 4-1: CONFIG1: CONFIGURATION WORD 1
R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 U-1
FCMEN IESO CLKOUTEN BOREN<1:0> —
bit 13 bit 8
R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1
CP MCLRE PWRTE WDTE<1:0> FOSC<2:0>
bit 7 bit 0
Legend:
R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘1’
‘0’ = Bit is cleared ‘1’ = Bit is set -n = Value when blank or after Bulk Erase
bit 13 FCMEN: Fail-Safe Clock Monitor Enable bit
1 = Fail-Safe Clock Monitor is enabled
0 = Fail-Safe Clock Monitor is disabled
bit 12 IESO: Internal External Switchover bit
1 = Internal/External Switchover mode is enabled
0 = Internal/External Switchover mode is disabled
bit 11 CLKOUTEN: Clock Out Enable bit
1 = CLKOUT function is disabled. I/O function on the CLKOUT pin
0 = CLKOUT function is enabled on the CLKOUT pin
bit 10-9 BOREN<1:0>: Brown-out Reset Enable bits(1)
11 = BOR enabled
10 = BOR enabled during operation and disabled in Sleep
01 = BOR controlled by SBOREN bit of the BORCON register
00 = BOR disabled
bit 8 Unimplemented: Read as ‘1’
bit 7 CP: Code Protection bit(2)
1 = Program memory code protection is disabled
0 = Program memory code protection is enabled
bit 6 MCLRE: MCLR/VPP Pin Function Select bit
If LVP bit = 1:
This bit is ignored.
If LVP bit = 0:
1 =MCLR
/VPP pin function is MCLR; Weak pull-up enabled.
0 =MCLR
/VPP pin function is digital input; MCLR internally disabled; Weak pull-up under control of
WPUE3 bit.
bit 5 PWRTE: Power-Up Timer Enable bit
1 = PWRT disabled
0 = PWRT enabled
bit 4-3 WDTE<1:0>: Watchdog Timer Enable bits
11 = WDT enabled
10 = WDT enabled while running and disabled in Sleep
01 = WDT controlled by the SWDTEN bit in the WDTCON register
00 = WDT disabled
bit 2-0 FOSC<2:0>: Oscillator Selection bits
111 = ECH:External clock, High-Power mode: on CLKIN pin
110 = ECM: External clock, Medium-Power mode: on CLKIN pin
101 = ECL: External clock, Low-Power mode: on CLKIN pin
100 = INTOSC oscillator: I/O function on CLKIN pin
011 = EXTRC oscillator: External RC circuit connected to CLKIN pin
010 = HS oscillator: High-speed crystal/resonator connected between OSC1 and OSC2 pins
001 = XT oscillator: Crystal/resonator connected between OSC1 and OSC2 pins
000 = LP oscillator: Low-power crystal connected between OSC1 and OSC2 pins
Note 1: Enabling Brown-out Reset does not automatically enable Power-up Timer.
2: Once enabled, code-protect can only be disabled by bulk erasing the device.
2011 Microchip Technology Inc. Preliminary DS41609A-page 45
PIC16(L)F1508/9
REGISTER 4-2: CONFIG2: CONFIGURATION WORD 2
R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 U-1
LVP DEBUG(3) LPBOR BORV STVREN —
bit 13 bit 8
U-1U-1U-1U-1U-1U-1R/P-1R/P-1
— — ————WRT<1:0>
bit 7 bit 0
Legend:
R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘1’
‘0’ = Bit is cleared ‘1’ = Bit is set -n = Value when blank or after Bulk Erase
bit 13 LVP: Low-Voltage Programming Enable bit(1)
1 = Low-voltage programming enabled
0 = High-voltage on MCLR must be used for programming
bit 12 DEBUG: In-Circuit Debugger Mode bit(3)
1 = In-Circuit Debugger disabled, ICSPCLK and ICSPDAT are general purpose I/O pins
0 = In-Circuit Debugger enabled, ICSPCLK and ICSPDAT are dedicated to the debugger
bit 11 LPBOR: Low-Power BOR Enable bit
1 = Low-Power Brown-out Reset is disabled
0 = Low-Power Brown-out Reset is enabled
bit 10 BORV: Brown-out Reset Voltage Selection bit(2)
1 = Brown-out Reset voltage (Vbor), low trip point selected.
0 = Brown-out Reset voltage (Vbor), high trip point selected.
bit 9 STVREN: Stack Overflow/Underflow Reset Enable bit
1 = Stack Overflow or Underflow will cause a Reset
0 = Stack Overflow or Underflow will not cause a Reset
bit 8-2 Unimplemented: Read as ‘1’
bit 1-0 WRT<1:0>: Flash Memory Self-Write Protection bits
2 kW Flash memory:
11 = Write protection off
10 = 000h to 1FFh write-protected, 200h to 7FFh may be modified
01 = 000h to 3FFh write-protected, 400h to 7FFh may be modified
00 = 000h to 7FFh write-protected, no addresses may be modified
Note 1: The LVP bit cannot be programmed to ‘0’ when Programming mode is entered via LVP.
2: See Vbor parameter for specific trip point voltages.
3: The DEBUG bit in Configuration Words is managed automatically by device development tools including
debuggers and programmers. For normal device operation, this bit should be maintained as a '1'.
PIC16(L)F1508/9
DS41609A-page 46 Preliminary 2011 Microchip Technology Inc.
4.2 Code Protection
Code protection allows the device to be protected from
unauthorized access. Internal access to the program
memory is unaffected by any code protection setting.
4.2.1 PROGRAM MEMORY PROTECTION
The entire program memory space is protected from
external reads and writes by the CP bit in Configuration
Words. When CP = 0, external reads and writes of
program memory are inhibited and a read will return all
‘0’s. The CPU can continue to read program memory,
regardless of the protection bit settings. Writing the
program memory is dependent upon the write
protection setting. See Section 4.3 “Write
Protection” for more information.
4.3 Write Protection
Write protection allows the device to be protected from
unintended self-writes. Applications, such as
bootloader software, can be protected while allowing
other regions of the program memory to be modified.
The WRT<1:0> bits in Configuration Words define the
size of the program memory block that is protected.
4.4 User ID
Four memory locations (8000h-8003h) are designated as
ID locations where the user can store checksum or other
code identification numbers. These locations are
readable and writable during normal execution. See
Section 10.4 “User ID, Device ID and Configuration
Word Access” for more information on accessing these
memory locations. For more information on checksum
calculation, see the “PIC12(L)F1501/PIC16(L)F150X
Memory Programming Specification” (DS41573).
2011 Microchip Technology Inc. Preliminary DS41609A-page 47
PIC16(L)F1508/9
4.5 Device ID and Revision ID
The memory location 8006h is where the Device ID and
Revision ID are stored. The upper nine bits hold the
Device ID. The lower five bits hold the Revision ID. See
Section 10.4 “User ID, Device ID and Configuration
Word Access” for more information on accessing
these memory locations.
Development tools, such as device programmers and
debuggers, may be used to read the Device ID and
Revision ID.
REGISTER 4-3: DEVICEID: DEVICE ID REGISTER
RRRRRR
DEV<8:3>
bit 13 bit 8
RRRRRRRR
DEV<2:0> REV<4:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘1’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared P = Programmable bit
bit 13-5 DEV<8:0>: Device ID bits
bit 4-0 REV<4:0>: Revision ID bits
These bits are used to identify the revision (see Table under DEV<8:0> above).
Device
DEVICEID<13:0> Values
DEV<8:0> REV<4:0>
PIC16F1508 10 1101 001 x xxxx
PIC16LF1508 10 1101 111 x xxxx
PIC16F1509 10 1101 010 x xxxx
PIC16LF1509 10 1101 000 x xxxx
PIC16(L)F1508/9
DS41609A-page 48 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 49
PIC16(L)F1508/9
5.0 OSCILLATOR MODULE (WITH
FAIL-SAFE CLOCK MONITOR)
5.1 Overview
The oscillator module has a wide variety of clock
sources and selection features that allow it to be used
in a wide range of applications while maximizing perfor-
mance and minimizing power consumption. Figure 5-1
illustrates a block diagram of the oscillator module.
Clock sources can be supplied from external oscillators,
quartz crystal resonators, ceramic resonators and
Resistor-Capacitor (RC) circuits. In addition, the system
clock source can be supplied from one of two internal
oscillators, with a choice of speeds selectable via
software. Additional clock features include:
• Selectable system clock source between external
or internal sources via software.
• Two-Speed Start-up mode, which minimizes
latency between external oscillator start-up and
code execution.
• Fail-Safe Clock Monitor (FSCM) designed to
detect a failure of the external clock source (LP,
XT, HS, EC or RC modes) and switch
automatically to the internal oscillator.
• Oscillator Start-up Timer (OST) ensures stability
of crystal oscillator sources
• Fast start-up oscillator allows internal circuits to
power-up and stabilize before switching to the 16
MHz HFINTOSC
The oscillator module can be configured in one of eight
clock modes.
1. ECL – External Clock Low-Power mode
(0 MHz to 0.5 MHz)
2. ECM – External Clock Medium-Power mode
(0.5 MHz to 4 MHz)
3. ECH – External Clock High-Power mode
(4 MHz to 20 MHz)
4. LP – 32 kHz Low-Power Crystal mode.
5. XT – Medium Gain Crystal or Ceramic Resonator
Oscillator mode (up to 4 MHz)
6. HS – High Gain Crystal or Ceramic Resonator
mode (4 MHz to 20 MHz)
7. RC – External Resistor-Capacitor (RC)
8. INTOSC – Internal oscillator (31 kHz to 16 MHz)
Clock Source modes are selected by the FOSC<2:0>
bits in the Configuration Words. The FOSC bits
determine the type of oscillator that will be used when
the device is first powered.
The EC clock mode relies on an external logic level
signal as the device clock source. The LP, XT, and HS
clock modes require an external crystal or resonator to
be connected to the device. Each mode is optimized for
a different frequency range. The RC clock mode
requires an external resistor and capacitor to set the
oscillator frequency.
The INTOSC internal oscillator block produces a low
and high-frequency clock source, designated
LFINTOSC and HFINTOSC. (See Internal Oscillator
Block, Figure 5-1). A wide selection of device clock
frequencies may be derived from these two clock
sources.
PIC16(L)F1508/9
DS41609A-page 50 Preliminary 2011 Microchip Technology Inc.
FIGURE 5-1: SIMPLIFIED PIC® MCU CLOCK SOURCE BLOCK DIAGRAM
Primary
Oscillator
(OSC)
Secondary
Oscillator
(SOSC)
Postscaler
MUX
16 MHz
8 MHz
4 MHz
2 MHz
1 MHz
500 kHz
250 kHz
125 kHz
62.5 kHz
31.25 kHz
31 kHz
WDT, PWRT and other Modules
MUX
Sleep
CPU and
Peripherals
Clock
Control
SCS<1:0>
FOSC<2:0>
CLKIN/ OSC1/
SOSCI/ T1CKI
CLKOUT / OSC2
SOSCO/ T1G
Primary Clock
Secondary Clock
INTOSC
IRCF<3:0>
16 MHz
Primary OSC
31 kHz
Source
Start-Up
OSC
Start-up
Control Logic
23
4
2011 Microchip Technology Inc. Preliminary DS41609A-page 51
PIC16(L)F1508/9
5.2 Clock Source Types
Clock sources can be classified as external or internal.
External clock sources rely on external circuitry for the
clock source to function. Examples are: oscillator mod-
ules (EC mode), quartz crystal resonators or ceramic
resonators (LP, XT and HS modes) and Resis-
tor-Capacitor (RC) mode circuits.
Internal clock sources are contained within the oscillator
module. The internal oscillator block has two internal
oscillators that are used to generate the internal system
clock sources: the 16 MHz High-Frequency Internal
Oscillator and the 31 kHz Low-Frequency Internal
Oscillator (LFINTOSC).
The system clock can be selected between external or
internal clock sources via the System Clock Select
(SCS) bits in the OSCCON register. See Section 5.3
“Clock Switching” for additional information.
5.2.1 EXTERNAL CLOCK SOURCES
An external clock source can be used as the device
system clock by performing one of the following
actions:
• Program the FOSC<2:0> bits in the Configuration
Words to select an external clock source that will
be used as the default system clock upon a
device Reset.
• Write the SCS<1:0> bits in the OSCCON register
to switch the system clock source to:
- Secondary oscillator during run-time, or
- An external clock source determined by the
value of the FOSC bits.
See Section 5.3 “Clock Switching”for more informa-
tion.
5.2.1.1 EC Mode
The External Clock (EC) mode allows an externally
generated logic level signal to be the system clock
source. When operating in this mode, an external clock
source is connected to the OSC1 input.
OSC2/CLKOUT is available for general purpose I/O or
CLKOUT. Figure 5-2 shows the pin connections for EC
mode.
EC mode has 3 power modes to select from through
Configuration Words:
• High power, 4-20 MHz (FOSC = 111)
• Medium power, 0.5-4 MHz (FOSC = 110)
• Low power, 0-0.5 MHz (FOSC = 101)
The Oscillator Start-up Timer (OST) is disabled when
EC mode is selected. Therefore, there is no delay in
operation after a Power-on Reset (POR) or wake-up
from Sleep. Because the PIC® MCU design is fully
static, stopping the external clock input will have the
effect of halting the device while leaving all data intact.
Upon restarting the external clock, the device will
resume operation as if no time had elapsed.
FIGURE 5-2: EXTERNAL CLOCK (EC)
MODE OPERATION
5.2.1.2 LP, XT, HS Modes
The LP, XT and HS modes support the use of quartz
crystal resonators or ceramic resonators connected to
OSC1 and OSC2 (Figure 5-3). The three modes select
a low, medium or high gain setting of the internal
inverter-amplifier to support various resonator types
and speed.
LP Oscillator mode selects the lowest gain setting of the
internal inverter-amplifier. LP mode current consumption
is the least of the three modes. This mode is designed to
drive only 32.768 kHz tuning-fork type crystals (watch
crystals).
XT Oscillator mode selects the intermediate gain
setting of the internal inverter-amplifier. XT mode
current consumption is the medium of the three modes.
This mode is best suited to drive resonators with a
medium drive level specification.
HS Oscillator mode selects the highest gain setting of the
internal inverter-amplifier. HS mode current consumption
is the highest of the three modes. This mode is best
suited for resonators that require a high drive setting.
Figure 5-3 and Figure 5-4 show typical circuits for
quartz crystal and ceramic resonators, respectively.
OSC1/CLKIN
OSC2/CLKOUT
Clock from
Ext. System
PIC® MCU
FOSC/4 or I/O(1)
Note 1: Output depends upon CLKOUTEN bit of the
Configuration Words.
PIC16(L)F1508/9
DS41609A-page 52 Preliminary 2011 Microchip Technology Inc.
FIGURE 5-3: QUARTZ CRYSTAL
OPERATION (LP, XT OR
HS MODE)
FIGURE 5-4: CERAMIC RESONATOR
OPERATION
(XT OR HS MODE)
5.2.1.3 Oscillator Start-up Timer (OST)
If the oscillator module is configured for LP, XT or HS
modes, the Oscillator Start-up Timer (OST) counts
1024 oscillations from OSC1. This occurs following a
Power-on Reset (POR) and when the Power-up Timer
(PWRT) has expired (if configured), or a wake-up from
Sleep. During this time, the program counter does not
increment and program execution is suspended. The
OST ensures that the oscillator circuit, using a quartz
crystal resonator or ceramic resonator, has started and
is providing a stable system clock to the oscillator
module.
In order to minimize latency between external oscillator
start-up and code execution, the Two-Speed Clock
Start-up mode can be selected (see Section 5.4
“Two-Speed Clock Start-up Mode”).
Note 1: Quartz crystal characteristics vary
according to type, package and
manufacturer. The user should consult the
manufacturer data sheets for specifications
and recommended application.
2: Always verify oscillator performance over
the VDD and temperature range that is
expected for the application.
3: For oscillator design assistance, reference
the following Microchip Applications Notes:
• AN826, “Crystal Oscillator Basics and
Crystal Selection for rfPIC® and PIC®
Devices” (DS00826)
• AN849, “Basic PIC® Oscillator Design”
(DS00849)
• AN943, “Practical PIC® Oscillator
Analysis and Design” (DS00943)
• AN949, “Making Your Oscillator Work”
(DS00949)
Note 1: A series resistor (RS) may be required for
quartz crystals with low drive level.
2: The value of RF varies with the Oscillator mode
selected (typically between 2 M to 10 M.
C1
C2
Quartz
RS(1)
OSC1/CLKIN
RF(2) Sleep
To Internal
Logic
PIC® MCU
Crystal
OSC2/CLKOUT
Note 1: A series resistor (RS) may be required for
ceramic resonators with low drive level.
2: The value of RF varies with the Oscillator mode
selected (typically between 2 M to 10 M.
3: An additional parallel feedback resistor (RP)
may be required for proper ceramic resonator
operation.
C1
C2 Ceramic RS(1)
OSC1/CLKIN
RF(2) Sleep
To Internal
Logic
PIC® MCU
RP(3)
Resonator
OSC2/CLKOUT
2011 Microchip Technology Inc. Preliminary DS41609A-page 53
PIC16(L)F1508/9
5.2.1.4 Secondary Oscillator
The secondary oscillator is a separate crystal oscillator
that is associated with the Timer1 peripheral. It is opti-
mized for timekeeping operations with a 32.768 kHz
crystal connected between the SOSCO and SOSCI
device pins.
The secondary oscillator can be used as an alternate
system clock source and can be selected during
run-time using clock switching. Refer to Section 5.3
“Clock Switching” for more information.
FIGURE 5-5: QUARTZ CRYSTAL
OPERATION
(SECONDARY
OSCILLATOR)
5.2.1.5 External RC Mode
The external Resistor-Capacitor (RC) modes support
the use of an external RC circuit. This allows the
designer maximum flexibility in frequency choice while
keeping costs to a minimum when clock accuracy is not
required.
The RC circuit connects to OSC1. OSC2/CLKOUT is
available for general purpose I/O or CLKOUT. The
function of the OSC2/CLKOUT pin is determined by the
CLKOUTEN bit in Configuration Words.
Figure 5-6 shows the external RC mode connections.
FIGURE 5-6: EXTERNAL RC MODES
The RC oscillator frequency is a function of the supply
voltage, the resistor (REXT) and capacitor (CEXT) values
and the operating temperature. Other factors affecting
the oscillator frequency are:
• threshold voltage variation
• component tolerances
• packaging variations in capacitance
The user also needs to take into account variation due
to tolerance of external RC components used.
Note 1: Quartz crystal characteristics vary
according to type, package and
manufacturer. The user should consult the
manufacturer data sheets for specifications
and recommended application.
2: Always verify oscillator performance over
the VDD and temperature range that is
expected for the application.
3: For oscillator design assistance, reference
the following Microchip Applications Notes:
• AN826, “Crystal Oscillator Basics and
Crystal Selection for rfPIC® and PIC®
Devices” (DS00826)
• AN849, “Basic PIC® Oscillator Design”
(DS00849)
• AN943, “Practical PIC® Oscillator
Analysis and Design” (DS00943)
• AN949, “Making Your Oscillator Work”
(DS00949)
• TB097, “Interfacing a Micro Crystal
MS1V-T1K 32.768 kHz Tuning Fork
Crystal to a PIC16F690/SS” (DS91097)
• AN1288, “Design Practices for
Low-Power External Oscillators”
(DS01288)
C1
C2
32.768 kHz
SOSCI
To Internal
Logic
PIC® MCU
Crystal
SOSCO
Quartz
OSC2/CLKOUT
CEXT
REXT
PIC® MCU
OSC1/CLKIN
FOSC/4 or
Internal
Clock
VDD
VSS
Recommended values: 10 k REXT 100 k, <3V
3 k REXT 100 k, 3-5V
CEXT > 20 pF, 2-5V
Note 1: Output depends upon CLKOUTEN bit of the
Configuration Words.
I/O(1)
PIC16(L)F1508/9
DS41609A-page 54 Preliminary 2011 Microchip Technology Inc.
5.2.2 INTERNAL CLOCK SOURCES
The device may be configured to use the internal oscil-
lator block as the system clock by performing one of the
following actions:
• Program the FOSC<2:0> bits in Configuration
Words to select the INTOSC clock source, which
will be used as the default system clock upon a
device Reset.
• Write the SCS<1:0> bits in the OSCCON register
to switch the system clock source to the internal
oscillator during run-time. See Section 5.3
“Clock Switching”for more information.
In INTOSC mode, OSC1/CLKIN is available for general
purpose I/O. OSC2/CLKOUT is available for general
purpose I/O or CLKOUT.
The function of the OSC2/CLKOUT pin is determined
by the CLKOUTEN bit in Configuration Words.
The internal oscillator block has two independent
oscillators that provides the internal system clock
source.
1. The HFINTOSC (High-Frequency Internal
Oscillator) is factory calibrated and operates at
16 MHz.
2. The LFINTOSC (Low-Frequency Internal
Oscillator) is uncalibrated and operates at
31 kHz.
5.2.2.1 HFINTOSC
The High-Frequency Internal Oscillator (HFINTOSC) is
a factory calibrated 16 MHz internal clock source.
The output of the HFINTOSC connects to a postscaler
and multiplexer (see Figure 5-1). The frequency derived
from the HFINTOSC can be selected via software using
the IRCF<3:0> bits of the OSCCON register. See
Section 5.2.2.4 “Internal Oscillator Clock Switch
Timing” for more information.
The HFINTOSC is enabled by:
• Configure the IRCF<3:0> bits of the OSCCON
register for the desired HF frequency, and
•FOSC<2:0> = 100, or
• Set the System Clock Source (SCS) bits of the
OSCCON register to ‘1x’.
A fast start-up oscillator allows internal circuits to
power-up and stabilize before switching to HFINTOSC.
The High-Frequency Internal Oscillator Ready bit
(HFIOFR) of the OSCSTAT register indicates when the
HFINTOSC is running.
The High-Frequency Internal Oscillator Stable bit
(HFIOFS) of the OSCSTAT register indicates when the
HFINTOSC is running within 0.5% of its final value.
5.2.2.2 LFINTOSC
The Low-Frequency Internal Oscillator (LFINTOSC) is
an uncalibrated 31 kHz internal clock source.
The output of the LFINTOSC connects to a postscaler
and multiplexer (see Figure 5-1). Select 31 kHz, via
software, using the IRCF<3:0> bits of the OSCCON
register. See Section 5.2.2.4 “Internal Oscillator
Clock Switch Timing” for more information. The
LFINTOSC is also the frequency for the Power-up Timer
(PWRT), Watchdog Timer (WDT) and Fail-Safe Clock
Monitor (FSCM).
The LFINTOSC is enabled by selecting 31 kHz
(IRCF<3:0> bits of the OSCCON register = 000) as the
system clock source (SCS bits of the OSCCON
register = 1x), or when any of the following are
enabled:
• Configure the IRCF<3:0> bits of the OSCCON
register for the desired LF frequency, and
•FOSC<2:0> = 100, or
• Set the System Clock Source (SCS) bits of the
OSCCON register to ‘1x’
Peripherals that use the LFINTOSC are:
• Power-up Timer (PWRT)
• Watchdog Timer (WDT)
• Fail-Safe Clock Monitor (FSCM)
The Low-Frequency Internal Oscillator Ready bit
(LFIOFR) of the OSCSTAT register indicates when the
LFINTOSC is running.
2011 Microchip Technology Inc. Preliminary DS41609A-page 55
PIC16(L)F1508/9
5.2.2.3 Internal Oscillator Frequency
Selection
The system clock speed can be selected via software
using the Internal Oscillator Frequency Select bits
IRCF<3:0> of the OSCCON register.
The output of the 16 MHz HFINTOSC and 31 kHz
LFINTOSC connects to a postscaler and multiplexer
(see Figure 5-1). The Internal Oscillator Frequency
Select bits IRCF<3:0> of the OSCCON register select
the frequency output of the internal oscillators. One of
the following frequencies can be selected via software:
•HFINTOSC
-16 MHz
-8 MHz
-4 MHz
-2 MHz
-1 MHz
- 500 kHz (default after Reset)
- 250 kHz
- 125 kHz
- 62.5 kHz
- 31.25 kHz
•LFINTOSC
-31 kHz
The IRCF<3:0> bits of the OSCCON register allow
duplicate selections for some frequencies. These dupli-
cate choices can offer system design trade-offs. Lower
power consumption can be obtained when changing
oscillator sources for a given frequency. Faster transi-
tion times can be obtained between frequency changes
that use the same oscillator source.
5.2.2.4 Internal Oscillator Clock Switch
Timing
When switching between the HFINTOSC and the
LFINTOSC, the new oscillator may already be shut
down to save power (see Figure 5-7). If this is the case,
there is a delay after the IRCF<3:0> bits of the
OSCCON register are modified before the frequency
selection takes place. The OSCSTAT register will
reflect the current active status of the HFINTOSC and
LFINTOSC oscillators. The sequence of a frequency
selection is as follows:
1. IRCF<3:0> bits of the OSCCON register are
modified.
2. If the new clock is shut down, a clock start-up
delay is started.
3. Clock switch circuitry waits for a falling edge of
the current clock.
4. The current clock is held low and the clock
switch circuitry waits for a rising edge in the new
clock.
5. The new clock is now active.
6. The OSCSTAT register is updated as required.
7. Clock switch is complete.
See Figure 5-7 for more details.
If the internal oscillator speed is switched between two
clocks of the same source, there is no start-up delay
before the new frequency is selected. Clock switching
time delays are shown in Table 5-1.
Start-up delay specifications are located in the
oscillator tables of Section 29.0 “Electrical
Specifications”.
Note: Following any Reset, the IRCF<3:0> bits
of the OSCCON register are set to ‘0111’
and the frequency selection is set to
500 kHz. The user can modify the IRCF
bits to select a different frequency.
PIC16(L)F1508/9
DS41609A-page 56 Preliminary 2011 Microchip Technology Inc.
FIGURE 5-7: INTERNAL OSCILLATOR SWITCH TIMING
HFINTOSC
LFINTOSC
IRCF <3:0>
System Clock
HFINTOSC
LFINTOSC
IRCF <3:0>
System Clock
00
00
Start-up Time 2-cycle Sync Running
2-cycle Sync Running
HFINTOSC LFINTOSC (FSCM and WDT disabled)
HFINTOSC LFINTOSC (Either FSCM or WDT enabled)
LFINTOSC
HFINTOSC
IRCF <3:0>
System Clock
= 0 0
Start-up Time 2-cycle Sync Running
LFINTOSC HFINTOSC LFINTOSC turns off unless WDT or FSCM is enabled
2011 Microchip Technology Inc. Preliminary DS41609A-page 57
PIC16(L)F1508/9
5.3 Clock Switching
The system clock source can be switched between
external and internal clock sources via software using
the System Clock Select (SCS) bits of the OSCCON
register. The following clock sources can be selected
using the SCS bits:
• Default system oscillator determined by FOSC
bits in Configuration Words
• Secondary oscillator 32 kHz crystal
• Internal Oscillator Block (INTOSC)
5.3.1 SYSTEM CLOCK SELECT (SCS)
BITS
The System Clock Select (SCS) bits of the OSCCON
register selects the system clock source that is used for
the CPU and peripherals.
• When the SCS bits of the OSCCON register = 00,
the system clock source is determined by value of
the FOSC<2:0> bits in the Configuration Words.
• When the SCS bits of the OSCCON register = 01,
the system clock source is the secondary
oscillator.
• When the SCS bits of the OSCCON register = 1x,
the system clock source is chosen by the internal
oscillator frequency selected by the IRCF<3:0>
bits of the OSCCON register. After a Reset, the
SCS bits of the OSCCON register are always
cleared.
When switching between clock sources, a delay is
required to allow the new clock to stabilize. These oscil-
lator delays are shown in Table 5-1.
5.3.2 OSCILLATOR START-UP TIME-OUT
STATUS (OSTS) BIT
The Oscillator Start-up Time-out Status (OSTS) bit of
the OSCSTAT register indicates whether the system
clock is running from the external clock source, as
defined by the FOSC<2:0> bits in the Configuration
Words, or from the internal clock source. In particular,
OSTS indicates that the Oscillator Start-up Timer
(OST) has timed out for LP, XT or HS modes. The OST
does not reflect the status of the secondary oscillator.
5.3.3 SECONDARY OSCILLATOR
The secondary oscillator is a separate crystal oscillator
associated with the Timer1 peripheral. It is optimized
for timekeeping operations with a 32.768 kHz crystal
connected between the SOSCO and SOSCI device
pins.
The secondary oscillator is enabled using the
T1OSCEN control bit in the T1CON register. See
Section 19.0 “Timer1 Module with Gate Control” for
more information about the Timer1 peripheral.
5.3.4 SECONDARY OSCILLATOR READY
(SOSCR) BIT
The user must ensure that the secondary oscillator is
ready to be used before it is selected as a system clock
source. The Secondary Oscillator Ready (SOSCR) bit
of the OSCSTAT register indicates whether the
secondary oscillator is ready to be used. After the
SOSCR bit is set, the SCS bits can be configured to
select the secondary oscillator.
Note: Any automatic clock switch, which may
occur from Two-Speed Start-up or
Fail-Safe Clock Monitor, does not update
the SCS bits of the OSCCON register. The
user can monitor the OSTS bit of the
OSCSTAT register to determine the current
system clock source.
PIC16(L)F1508/9
DS41609A-page 58 Preliminary 2011 Microchip Technology Inc.
5.4 Two-Speed Clock Start-up Mode
Two-Speed Start-up mode provides additional power
savings by minimizing the latency between external
oscillator start-up and code execution. In applications
that make heavy use of the Sleep mode, Two-Speed
Start-up will remove the external oscillator start-up
time from the time spent awake and can reduce the
overall power consumption of the device. This mode
allows the application to wake-up from Sleep, perform
a few instructions using the INTOSC internal oscillator
block as the clock source and go back to Sleep without
waiting for the external oscillator to become stable.
Two-Speed Start-up provides benefits when the oscil-
lator module is configured for LP, XT, or HS modes.
The Oscillator Start-up Timer (OST) is enabled for
these modes and must count 1024 oscillations before
the oscillator can be used as the system clock source.
If the oscillator module is configured for any mode
other than LP, XT or HS mode, then Two-Speed
Start-up is disabled. This is because the external clock
oscillator does not require any stabilization time after
POR or an exit from Sleep.
If the OST count reaches 1024 before the device
enters Sleep mode, the OSTS bit of the OSCSTAT reg-
ister is set and program execution switches to the
external oscillator. However, the system may never
operate from the external oscillator if the time spent
awake is very short.
5.4.1 TWO-SPEED START-UP MODE
CONFIGURATION
Two-Speed Start-up mode is configured by the
following settings:
• IESO (of the Configuration Words) = 1; Inter-
nal/External Switchover bit (Two-Speed Start-up
mode enabled).
• SCS (of the OSCCON register) = 00.
• FOSC<2:0> bits in the Configuration Words
configured for LP, XT or HS mode.
Two-Speed Start-up mode is entered after:
• Power-on Reset (POR) and, if enabled, after
Power-up Timer (PWRT) has expired, or
• Wake-up from Sleep.
TABLE 5-1: OSCILLATOR SWITCHING DELAYS
Note: Executing a SLEEP instruction will abort
the oscillator start-up time and will cause
the OSTS bit of the OSCSTAT register to
remain clear.
Switch From Switch To Frequency Oscillator Delay
Sleep/POR LFINTOSC
HFINTOSC
31 kHz
31.25kHz-16MHz Oscillator Warm-up Delay (TWARM)
Sleep/POR EC, RC DC – 20 MHz 2 cycles
LFINTOSC EC, RC DC – 20 MHz 1 cycle of each
Sleep/POR Secondary Oscillator,
LP, XT, HS 32 kHz-20 MHz 1024 Clock Cycles (OST)
Any clock source HFINTOSC 31.25 kHz-16 MHz 2 s (approx.)
Any clock source LFINTOSC 31 kHz 1 cycle of each
Any clock source Secondary Oscillator 32 kHz 1024 Clock Cycles (OST)
2011 Microchip Technology Inc. Preliminary DS41609A-page 59
PIC16(L)F1508/9
5.4.2 TWO-SPEED START-UP
SEQUENCE
1. Wake-up from Power-on Reset or Sleep.
2. Instructions begin execution by the internal
oscillator at the frequency set in the IRCF<3:0>
bits of the OSCCON register.
3. OST enabled to count 1024 clock cycles.
4. OST timed out, wait for falling edge of the
internal oscillator.
5. OSTS is set.
6. System clock held low until the next falling edge
of new clock (LP, XT or HS mode).
7. System clock is switched to external clock
source.
5.4.3 CHECKING TWO-SPEED CLOCK
STATUS
Checking the state of the OSTS bit of the OSCSTAT
register will confirm if the microcontroller is running
from the external clock source, as defined by the
FOSC<2:0> bits in the Configuration Words, or the
internal oscillator.
FIGURE 5-8: TWO-SPEED START-UP
0 1 1022 1023
PC + 1
TOSTT
INTOSC
OSC1
OSC2
Program Counter
System Clock
PC - N PC
PIC16(L)F1508/9
DS41609A-page 60 Preliminary 2011 Microchip Technology Inc.
5.5 Fail-Safe Clock Monitor
The Fail-Safe Clock Monitor (FSCM) allows the device
to continue operating should the external oscillator fail.
The FSCM can detect oscillator failure any time after
the Oscillator Start-up Timer (OST) has expired. The
FSCM is enabled by setting the FCMEN bit in the
Configuration Words. The FSCM is applicable to all
external Oscillator modes (LP, XT, HS, EC, RC and
secondary oscillator).
FIGURE 5-9: FSCM BLOCK DIAGRAM
5.5.1 FAIL-SAFE DETECTION
The FSCM module detects a failed oscillator by
comparing the external oscillator to the FSCM sample
clock. The sample clock is generated by dividing the
LFINTOSC by 64. See Figure 5-9. Inside the fail
detector block is a latch. The external clock sets the
latch on each falling edge of the external clock. The
sample clock clears the latch on each rising edge of the
sample clock. A failure is detected when an entire
half-cycle of the sample clock elapses before the
external clock goes low.
5.5.2 FAIL-SAFE OPERATION
When the external clock fails, the FSCM switches the
device clock to an internal clock source and sets the bit
flag OSFIF of the PIR2 register. Setting this flag will
generate an interrupt if the OSFIE bit of the PIE2
register is also set. The device firmware can then take
steps to mitigate the problems that may arise from a
failed clock. The system clock will continue to be
sourced from the internal clock source until the device
firmware successfully restarts the external oscillator
and switches back to external operation.
The internal clock source chosen by the FSCM is
determined by the IRCF<3:0> bits of the OSCCON
register. This allows the internal oscillator to be
configured before a failure occurs.
5.5.3 FAIL-SAFE CONDITION CLEARING
The Fail-Safe condition is cleared after a Reset,
executing a SLEEP instruction or changing the SCS bits
of the OSCCON register. When the SCS bits are
changed, the OST is restarted. While the OST is
running, the device continues to operate from the
INTOSC selected in OSCCON. When the OST times
out, the Fail-Safe condition is cleared and the device
will be operating from the external clock source. The
Fail-Safe condition must be cleared before the OSFIF
flag can be cleared.
5.5.4 RESET OR WAKE-UP FROM SLEEP
The FSCM is designed to detect an oscillator failure
after the Oscillator Start-up Timer (OST) has expired.
The OST is used after waking up from Sleep and after
any type of Reset. The OST is not used with the EC or
RC Clock modes so that the FSCM will be active as
soon as the Reset or wake-up has completed. When
the FSCM is enabled, the Two-Speed Start-up is also
enabled. Therefore, the device will always be executing
code while the OST is operating.
External
LFINTOSC ÷ 64
S
R
Q
31 kHz
(~32 s)
488 Hz
(~2 ms)
Clock Monitor
Latch
Clock
Failure
Detected
Oscillator
Clock
Q
Sample Clock
Note: Due to the wide range of oscillator start-up
times, the Fail-Safe circuit is not active
during oscillator start-up (i.e., after exiting
Reset or Sleep). After an appropriate
amount of time, the user should check the
Status bits in the OSCSTAT register to
verify the oscillator start-up and that the
system clock switchover has successfully
completed.
2011 Microchip Technology Inc. Preliminary DS41609A-page 61
PIC16(L)F1508/9
FIGURE 5-10: FSCM TIMING DIAGRAM
OSCFIF
System
Clock
Output
Sample Clock
Failure
Detected
Oscillator
Failure
Note: The system clock is normally at a much higher frequency than the sample clock. The relative frequencies in
this example have been chosen for clarity.
(Q)
Te s t Test Test
Clock Monitor Output
PIC16(L)F1508/9
DS41609A-page 62 Preliminary 2011 Microchip Technology Inc.
5.6 Oscillator Control Registers
REGISTER 5-1: OSCCON: OSCILLATOR CONTROL REGISTER
U-0 R/W-0/0 R/W-1/1 R/W-1/1 R/W-1/1 U-0 R/W-0/0 R/W-0/0
—IRCF<3:0> —SCS<1:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 Unimplemented: Read as ‘0’
bit 6-3 IRCF<3:0>: Internal Oscillator Frequency Select bits
1111 =16MHz
1110 =8MHz
1101 =4MHz
1100 =2MHz
1011 =1MHz
1010 = 500 kHz(1)
1001 = 250 kHz(1)
1000 = 125 kHz(1)
0111 = 500 kHz (default upon Reset)
0110 = 250 kHz
0101 = 125 kHz
0100 = 62.5 kHz
001x = 31.25 kHz
000x =31kHz LF
bit 2 Unimplemented: Read as ‘0’
bit 1-0 SCS<1:0>: System Clock Select bits
1x = Internal oscillator block
01 = Secondary oscillator
00 = Clock determined by FOSC<2:0> in Configuration Words.
Note 1: Duplicate frequency derived from HFINTOSC.
2011 Microchip Technology Inc. Preliminary DS41609A-page 63
PIC16(L)F1508/9
TABLE 5-2: SUMMARY OF REGISTERS ASSOCIATED WITH CLOCK SOURCES
TABLE 5-3: SUMMARY OF CONFIGURATION WORD WITH CLOCK SOURCES
REGISTER 5-2: OSCSTAT: OSCILLATOR STATUS REGISTER
R-1/q U-0 R-q/q R-0/q U-0 U-0 R-0/q R-0/q
SOSCR —OSTS HFIOFR — — LFIOFR HFIOFS
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared q = Conditional
bit 7 SOSCR: Secondary Oscillator Ready bit
If T1OSCEN = 1:
1 = Secondary oscillator is ready
0 = Secondary oscillator is not ready
If T1OSCEN = 0:
1 = Timer1 clock source is always ready
bit 6 Unimplemented: Read as ‘0’
bit 5 OSTS: Oscillator Start-up Time-out Status bit
1 = Running from the clock defined by the FOSC<2:0> bits of the Configuration Words
0 = Running from an internal oscillator (FOSC<2:0> = 100)
bit 4 HFIOFR: High-Frequency Internal Oscillator Ready bit
1 = HFINTOSC is ready
0 = HFINTOSC is not ready
bit 3-2 Unimplemented: Read as ‘0’
bit 1 LFIOFR: Low-Frequency Internal Oscillator Ready bit
1 = LFINTOSC is ready
0 = LFINTOSC is not ready
bit 0 HFIOFS: High-Frequency Internal Oscillator Stable bit
1 = HFINTOSC 16 MHz Oscillator is stable and is driving the INTOSC
0 = HFINTOSC 16 MHz is not stable, the Start-up Oscillator is driving INTOSC
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
OSCCON — IRCF<3:0> —SCS<1:0>62
OSCSTAT SOSCR —OSTSHFIOFR—— LFIOFR HFIOFS 63
PIE2 OSFIE C2IE C1IE —BCL1IE NCO1IE — — 80
PIR2 OSFIF C2IF C1IF —BCL1IF NCO1IF ——83
T1CON TMR1CS<1:0> T1CKPS<1:0> T1OSCEN T1SYNC —TMR1ON 175
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by clock sources.
Name Bits Bit -/7 Bit -/6 Bit 13/5 Bit 12/4 Bit 11/3 Bit 10/2 Bit 9/1 Bit 8/0 Register
on Page
CONFIG1 13:8 —— FCMEN IESO CLKOUTEN BOREN<1:0> —44
7:0 CP MCLRE PWRTE WDTE<1:0> FOSC<2:0>
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by clock sources.
PIC16(L)F1508/9
DS41609A-page 64 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 65
PIC16(L)F1508/9
6.0 RESETS
There are multiple ways to reset this device:
• Power-on Reset (POR)
• Brown-out Reset (BOR)
• Low-Power Brown-out Reset (LPBOR)
•MCLR Reset
•WDT Reset
•RESET instruction
• Stack Overflow
• Stack Underflow
• Programming mode exit
To allow VDD to stabilize, an optional Power-up Timer
can be enabled to extend the Reset time after a BOR
or POR event.
A simplified block diagram of the On-Chip Reset Circuit
is shown in Figure 6-1.
FIGURE 6-1: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
Note 1: See Table 6-1 for BOR active conditions.
Device
Reset
Power-on
Reset
WDT
Time-out
Brown-out
Reset
LPBOR
Reset
RESET Instruction
MCLRE
Sleep
BOR
Active(1)
PWRT
R
Done
PWRTE
LFINTOSC
VDD
ICSP™ Programming Mode Exit
Stack
Pointer
MCLR
PIC16(L)F1508/9
DS41609A-page 66 Preliminary 2011 Microchip Technology Inc.
6.1 Power-on Reset (POR)
The POR circuit holds the device in Reset until VDD has
reached an acceptable level for minimum operation.
Slow rising VDD, fast operating speeds or analog
performance may require greater than minimum VDD.
The PWRT, BOR or MCLR features can be used to
extend the start-up period until all device operation
conditions have been met.
6.1.1 POWER-UP TIMER (PWRT)
The Power-up Timer provides a nominal 64 ms time-
out on POR or Brown-out Reset.
The device is held in Reset as long as PWRT is active.
The PWRT delay allows additional time for the VDD to
rise to an acceptable level. The Power-up Timer is
enabled by clearing the PWRTE bit in Configuration
Words.
The Power-up Timer starts after the release of the POR
and BOR.
For additional information, refer to Application Note
AN607, “Power-up Trouble Shooting” (DS00607).
6.2 Brown-Out Reset (BOR)
The BOR circuit holds the device in Reset when VDD
reaches a selectable minimum level. Between the
POR and BOR, complete voltage range coverage for
execution protection can be implemented.
The Brown-out Reset module has four operating
modes controlled by the BOREN<1:0> bits in Configu-
ration Words. The four operating modes are:
• BOR is always on
• BOR is off when in Sleep
• BOR is controlled by software
• BOR is always off
Refer to Tab le 6-1 for more information.
The Brown-out Reset voltage level is selectable by
configuring the BORV bit in Configuration Words.
A VDD noise rejection filter prevents the BOR from trig-
gering on small events. If VDD falls below VBOR for a
duration greater than parameter TBORDC, the device
will reset. See Figure 6-2 for more information.
TABLE 6-1: BOR OPERATING MODES
6.2.1 BOR IS ALWAYS ON
When the BOREN bits of Configuration Words are pro-
grammed to ‘11’, the BOR is always on. The device
start-up will be delayed until the BOR is ready and VDD
is higher than the BOR threshold.
BOR protection is active during Sleep. The BOR does
not delay wake-up from Sleep.
6.2.2 BOR IS OFF IN SLEEP
When the BOREN bits of Configuration Words are pro-
grammed to ‘10’, the BOR is on, except in Sleep. The
device start-up will be delayed until the BOR is ready
and VDD is higher than the BOR threshold.
BOR protection is not active during Sleep. The device
wake-up will be delayed until the BOR is ready.
6.2.3 BOR CONTROLLED BY SOFTWARE
When the BOREN bits of Configuration Words are
programmed to ‘01’, the BOR is controlled by the
SBOREN bit of the BORCON register. The device
start-up is not delayed by the BOR ready condition or
the VDD level.
BOR protection begins as soon as the BOR circuit is
ready. The status of the BOR circuit is reflected in the
BORRDY bit of the BORCON register.
BOR protection is unchanged by Sleep.
BOREN<1:0> SBOREN Device Mode BOR Mode Instruction Execution upon:
Release of POR or Wake-up from Sleep
11 X X Active Waits for BOR ready(1)
(BORRDY = 1)
10 X
Awake Active Waits for BOR ready
(BORRDY = 1)
Sleep Disabled
01
1XActive Waits for BOR ready(1)
(BORRDY = 1)
0X Disabled Begins immediately
(BORRDY = x)
00 X XDisabled
Note 1: In these specific cases, “release of POR” and “wake-up from Sleep,” there is no delay in start-up. The BOR
ready flag, (BORRDY = 1), will be set before the CPU is ready to execute instructions because the BOR
circuit is forced on by the BOREN<1:0> bits.
2011 Microchip Technology Inc. Preliminary DS41609A-page 67
PIC16(L)F1508/9
FIGURE 6-2: BROWN-OUT SITUATIONS
REGISTER 6-1: BORCON: BROWN-OUT RESET CONTROL REGISTER
R/W-1/u R/W-0/u U-0 U-0 U-0 U-0 U-0 R-q/u
SBOREN BORFS — — — — —BORRDY
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared q = Value depends on condition
bit 7 SBOREN: Software Brown-out Reset Enable bit
If BOREN <1:0> in Configuration Words 01:
SBOREN is read/write, but has no effect on the BOR.
If BOREN <1:0> in Configuration Words = 01:
1 = BOR Enabled
0 = BOR Disabled
bit 6 BORFS: Brown-out Reset Fast Start bit(1)
If BOREN<1:0> = 11 (Always on) or BOREN<1:0> = 00 (Always off)
BORFS is Read/Write, but has no effect.
If BOREN <1:0> = 10 (Disabled in Sleep) or BOREN<1:0> = 01 (Under software control):
1 = Band gap is forced on always (covers sleep/wake-up/operating cases)
0 = Band gap operates normally, and may turn off
bit 5-1 Unimplemented: Read as ‘0’
bit 0 BORRDY: Brown-out Reset Circuit Ready Status bit
1 = The Brown-out Reset circuit is active
0 = The Brown-out Reset circuit is inactive
Note 1: BOREN<1:0> bits are located in Configuration Words.
TPWRT(1)
VBOR
VDD
Internal
Reset
VBOR
VDD
Internal
Reset TPWRT(1)
< TPWRT
TPWRT(1)
VBOR
VDD
Internal
Reset
Note 1: TPWRT delay only if PWRTE bit is programmed to ‘0’.
PIC16(L)F1508/9
DS41609A-page 68 Preliminary 2011 Microchip Technology Inc.
6.3 Low-Power Brown-out Reset
(LPBOR)
The Low-Power Brown-Out Reset (LPBOR) is an
essential part of the Reset subsystem. Refer to
Figure 6-1 to see how the BOR interacts with other
modules.
The LPBOR is used to monitor the external VDD pin.
When too low of a voltage is detected, the device is
held in Reset. When this occurs, a register bit (BOR) is
changed to indicate that a BOR Reset has occurred.
The same bit is set for both the BOR and the LPBOR.
Refer to Register 6-2.
6.3.1 ENABLING LPBOR
The LPBOR is controlled by the LPBOR bit of
Configuration Words. When the device is erased, the
LPBOR module defaults to disabled.
6.3.1.1 LPBOR Module Output
The output of the LPBOR module is a signal indicating
whether or not a Reset is to be asserted. This signal is
OR’d together with the Reset signal of the BOR mod-
ule to provide the generic BOR signal which goes to
the PCON register and to the power control block.
6.4 MCLR
The MCLR is an optional external input that can reset
the device. The MCLR function is controlled by the
MCLRE bit of Configuration Words and the LVP bit of
Configuration Words (Table 6-2).
6.4.1 MCLR ENABLED
When MCLR is enabled and the pin is held low, the
device is held in Reset. The MCLR pin is connected to
VDD through an internal weak pull-up.
The device has a noise filter in the MCLR Reset path.
The filter will detect and ignore small pulses.
6.4.2 MCLR DISABLED
When MCLR is disabled, the pin functions as a general
purpose input and the internal weak pull-up is under
software control. See Section 11.2 “PORTA Regis-
ters” for more information.
6.5 Watchdog Timer (WDT) Reset
The Watchdog Timer generates a Reset if the firmware
does not issue a CLRWDT instruction within the time-out
period. The TO and PD bits in the STATUS register are
changed to indicate the WDT Reset. See Section 9.0
“Watchdog Timer” for more information.
6.6 RESET Instruction
A RESET instruction will cause a device Reset. The RI
bit in the PCON register will be set to ‘0’. See Ta bl e 6- 4
for default conditions after a RESET instruction has
occurred.
6.7 Stack Overflow/Underflow Reset
The device can reset when the Stack Overflows or
Underflows. The STKOVF or STKUNF bits of the PCON
register indicate the Reset condition. These Resets are
enabled by setting the STVREN bit in Configuration
Words. See Section 3.4.2 “Overflow/Underflow
Reset” for more information.
6.8 Programming Mode Exit
Upon exit of Programming mode, the device will
behave as if a POR had just occurred.
6.9 Power-Up Timer
The Power-up Timer optionally delays device execution
after a BOR or POR event. This timer is typically used to
allow VDD to stabilize before allowing the device to start
running.
The Power-up Timer is controlled by the PWRTE bit of
Configuration Words.
6.10 Start-up Sequence
Upon the release of a POR or BOR, the following must
occur before the device will begin executing:
1. Power-up Timer runs to completion (if enabled).
2. MCLR must be released (if enabled).
The total time-out will vary based on oscillator configu-
ration and Power-up Timer configuration. See
Section 5.0 “Oscillator Module (With Fail-Safe
Clock Monitor)” for more information.
The Power-up Timer runs independently of MCLR
Reset. If MCLR is kept low long enough, the Power-up
Timer will expire. Upon bringing MCLR high, the device
will begin execution immediately (see Figure 6-3). This
is useful for testing purposes or to synchronize more
than one device operating in parallel.
TABLE 6-2: MCLR CONFIGURATION
MCLRE LVP MCLR
00Disabled
10Enabled
x1Enabled
Note: A Reset does not drive the MCLR pin low.
2011 Microchip Technology Inc. Preliminary DS41609A-page 69
PIC16(L)F1508/9
FIGURE 6-3: RESET START-UP SEQUENCE
TMCLR
TPWRT
VDD
Internal POR
Power-Up Timer
MCLR
Internal RESET
Internal Oscillator
Oscillator
FOSC
External Clock (EC)
CLKIN
FOSC
PIC16(L)F1508/9
DS41609A-page 70 Preliminary 2011 Microchip Technology Inc.
6.11 Determining the Cause of a Reset
Upon any Reset, multiple bits in the STATUS and
PCON registers are updated to indicate the cause of
the Reset. Tab l e 6- 3 and Table 6 -4 show the Reset
conditions of these registers.
TABLE 6-3: RESET STATUS BITS AND THEIR SIGNIFICANCE
TABLE 6-4: RESET CONDITION FOR SPECIAL REGISTERS(2)
STKOVF STKUNF RWDT RMCLR RI POR BOR TO PD Condition
0 0 1 1 10 x11Power-on Reset
0 0 1 1 10 x0xIllegal, TO is set on POR
0 0 1 1 10 xx0Illegal, PD is set on POR
0 0 u 1 1u 011Brown-out Reset
u u 0 u uu u0uWDT Reset
u u u u uu u00WDT Wake-up from Sleep
u u u u uu u10Interrupt Wake-up from Sleep
u u u 0 uu uuuMCLR Reset during normal operation
u u u 0 uu u10MCLR Reset during Sleep
u u u u 0 u u u u RESET Instruction Executed
1 u u u uu uuuStack Overflow Reset (STVREN = 1)
u 1 u u uu uuuStack Underflow Reset (STVREN = 1)
Condition Program
Counter
STATUS
Register
PCON
Register
Power-on Reset 0000h ---1 1000 00-- 110x
MCLR Reset during normal operation 0000h ---u uuuu uu-- 0uuu
MCLR Reset during Sleep 0000h ---1 0uuu uu-- 0uuu
WDT Reset 0000h ---0 uuuu uu-- uuuu
WDT Wake-up from Sleep PC + 1 ---0 0uuu uu-- uuuu
Brown-out Reset 0000h ---1 1uuu 00-- 11u0
Interrupt Wake-up from Sleep PC + 1(1) ---1 0uuu uu-- uuuu
RESET Instruction Executed 0000h ---u uuuu uu-- u0uu
Stack Overflow Reset (STVREN = 1) 0000h ---u uuuu 1u-- uuuu
Stack Underflow Reset (STVREN = 1) 0000h ---u uuuu u1-- uuuu
Legend: u = unchanged, x = unknown, - = unimplemented bit, reads as ‘0’.
Note 1: When the wake-up is due to an interrupt and Global Interrupt Enable bit (GIE) is set, the return address is
pushed on the stack and PC is loaded with the interrupt vector (0004h) after execution of PC + 1.
2: If a Status bit is not implemented, that bit will be read as ‘0’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 71
PIC16(L)F1508/9
6.12 Power Control (PCON) Register
The Power Control (PCON) register contains flag bits
to differentiate between a:
• Power-on Reset (POR)
• Brown-out Reset (BOR)
• Reset Instruction Reset (RI)
•MCLR Reset (RMCLR)
• Watchdog Timer Reset (RWDT)
• Stack Underflow Reset (STKUNF)
• Stack Overflow Reset (STKOVF)
The PCON register bits are shown in Register 6-2.
REGISTER 6-2: PCON: POWER CONTROL REGISTER
R/W/HS-0/q R/W/HS-0/q U-0 R/W/HC-1/q R/W/HC-1/q R/W/HC-1/q R/W/HC-q/u R/W/HC-q/u
STKOVF STKUNF —RWDT RMCLR RI POR BOR
bit 7 bit 0
Legend:
HC = Bit is cleared by hardware HS = Bit is set by hardware
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared q = Value depends on condition
bit 7 STKOVF: Stack Overflow Flag bit
1 = A Stack Overflow occurred
0 = A Stack Overflow has not occurred or cleared by firmware
bit 6 STKUNF: Stack Underflow Flag bit
1 = A Stack Underflow occurred
0 = A Stack Underflow has not occurred or cleared by firmware
bit 5 Unimplemented: Read as ‘0’
bit 4 RWDT: Watchdog Timer Reset Flag bit
1 = A Watchdog Timer Reset has not occurred or set by firmware
0 = A Watchdog Timer Reset has occurred (cleared by hardware)
bit 3 RMCLR: MCLR Reset Flag bit
1 = A MCLR Reset has not occurred or set by firmware
0 = A MCLR Reset has occurred (cleared by hardware)
bit 2 RI: RESET Instruction Flag bit
1 = A RESET instruction has not been executed or set by firmware
0 = A RESET instruction has been executed (cleared by hardware)
bit 1 POR: Power-on Reset Status bit
1 = No Power-on Reset occurred
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 = No Brown-out Reset occurred
0 = A Brown-out Reset occurred (must be set in software after a Power-on Reset or Brown-out Reset
occurs)
PIC16(L)F1508/9
DS41609A-page 72 Preliminary 2011 Microchip Technology Inc.
TABLE 6-5: SUMMARY OF REGISTERS ASSOCIATED WITH RESETS
TABLE 6-6: SUMMARY OF CONFIGURATION WORD WITH RESETS
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
BORCON SBOREN BORFS ————— BORRDY 67
PCON STKOVF STKUNF —RWDTRMCLR RI POR BOR 71
STATUS — — —TOPD ZDC C21
WDTCON —— WDTPS<4:0> SWDTEN 93
Legend: — = unimplemented bit, reads as ‘0’. Shaded cells are not used by Resets.
Note 1: Other (non Power-up) Resets include MCLR Reset and Watchdog Timer Reset during normal operation.
Name Bits Bit -/7 Bit -/6 Bit 13/5 Bit 12/4 Bit 11/3 Bit 10/2 Bit 9/1 Bit 8/0 Register
on Page
CONFIG1 13:8 — — — — CLKOUTEN BOREN<1:0> —44
7:0 CP MCLRE PWRTE WDTE<1:0> FOSC<2:0>
CONFIG2 13:8 — — LVP DEBUG LPBOR BORV STVREN —45
7:0 — — — — — — WRT<1:0>
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by Resets.
2011 Microchip Technology Inc. Preliminary DS41609A-page 73
PIC16(L)F1508/9
7.0 INTERRUPTS
The interrupt feature allows certain events to preempt
normal program flow. Firmware is used to determine
the source of the interrupt and act accordingly. Some
interrupts can be configured to wake the MCU from
Sleep mode.
This chapter contains the following information for
Interrupts:
• Operation
• Interrupt Latency
• Interrupts During Sleep
•INT Pin
• Automatic Context Saving
Many peripherals produce interrupts. Refer to the
corresponding chapters for details.
A block diagram of the interrupt logic is shown in
Figure 7-1.
FIGURE 7-1: INTERRUPT LOGIC
TMR0IF
TMR0IE
INTF
INTE
IOCIF
IOCIE Interrupt
to CPU
Wake-up
(If in Sleep mode)
GIE
(TMR1IF) PIR1<0>
PIRn<7>
PIEn<7>
PEIE
Peripheral Interrupts
(TMR1IF) PIR1<0>
PIC16(L)F1508/9
DS41609A-page 74 Preliminary 2011 Microchip Technology Inc.
7.1 Operation
Interrupts are disabled upon any device Reset. They
are enabled by setting the following bits:
• GIE bit of the INTCON register
• Interrupt Enable bit(s) for the specific interrupt
event(s)
• PEIE bit of the INTCON register (if the Interrupt
Enable bit of the interrupt event is contained in the
PIE1, PIE2 and PIE3 registers)
The INTCON, PIR1, PIR2 and PIR3 registers record
individual interrupts via interrupt flag bits. Interrupt flag
bits will be set, regardless of the status of the GIE, PEIE
and individual interrupt enable bits.
The following events happen when an interrupt event
occurs while the GIE bit is set:
• Current prefetched instruction is flushed
• GIE bit is cleared
• Current Program Counter (PC) is pushed onto the
stack
• Critical registers are automatically saved to the
Shadow registers (See “Section 7.5 “Automatic
Context Saving”.”)
• PC is loaded with the interrupt vector 0004h
The firmware within the Interrupt Service Routine (ISR)
should determine the source of the interrupt by polling
the interrupt flag bits. The interrupt flag bits must be
cleared before exiting the ISR to avoid repeated
interrupts. Because the GIE bit is cleared, any interrupt
that occurs while executing the ISR will be recorded
through its interrupt flag, but will not cause the
processor to redirect to the interrupt vector.
The RETFIE instruction exits the ISR by popping the
previous address from the stack, restoring the saved
context from the Shadow registers and setting the GIE
bit.
For additional information on a specific interrupt’s
operation, refer to its peripheral chapter.
7.2 Interrupt Latency
Interrupt latency is defined as the time from when the
interrupt event occurs to the time code execution at the
interrupt vector begins. The latency for synchronous
interrupts is 3 or 4 instruction cycles. For asynchronous
interrupts, the latency is 3 to 5 instruction cycles,
depending on when the interrupt occurs. See Figure 7-2
and Figure 7.3 for more details.
Note 1: Individual interrupt flag bits are set,
regardless of the state of any other
enable bits.
2: All interrupts will be ignored while the GIE
bit is cleared. Any interrupt occurring
while the GIE bit is clear will be serviced
when the GIE bit is set again.
2011 Microchip Technology Inc. Preliminary DS41609A-page 75
PIC16(L)F1508/9
FIGURE 7-2: INTERRUPT LATENCY
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Fosc
CLKR
PC 0004h 0005h
PC
Inst(0004h)NOP
GIE
Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4
1 Cycle Instruction at PC
PC
Inst(0004h)NOP
2 Cycle Instruction at PC
FSR ADDR PC+1 PC+2 0004h 0005h
PC
Inst(0004h)NOP
GIE
PCPC-1
3 Cycle Instruction at PC
Execute
Interrupt
Inst(PC)
Interrupt Sampled
during Q1
Inst(PC)
PC-1 PC+1
NOP
PC New PC/
PC+1 0005hPC-1 PC+1/FSR
ADDR 0004h
NOP
Interrupt
GIE
Interrupt
INST(PC) NOPNOP
FSR ADDR PC+1 PC+2 0004h 0005h
PC
Inst(0004h)NOP
GIE
PCPC-1
3 Cycle Instruction at PC
Interrupt
INST(PC) NOPNOP NOP
Inst(0005h)
Execute
Execute
Execute
PIC16(L)F1508/9
DS41609A-page 76 Preliminary 2011 Microchip Technology Inc.
FIGURE 7-3: INT PIN INTERRUPT TIMING
Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4
FOSC
CLKOUT
INT pin
INTF
GIE
INSTRUCTION FLOW
PC
Instruction
Fetched
Instruction
Executed
Interrupt Latency
PC PC + 1 PC + 1 0004h 0005h
Inst (0004h) Inst (0005h)
Forced NOP
Inst (PC) Inst (PC + 1)
Inst (PC – 1) Inst (0004h)
Forced NOP
Inst (PC)
—
Note 1: INTF flag is sampled here (every Q1).
2: Asynchronous interrupt latency = 3-5 TCY. Synchronous latency = 3-4 TCY, where TCY = instruction cycle time.
Latency is the same whether Inst (PC) is a single cycle or a 2-cycle instruction.
3: For minimum width of INT pulse, refer to AC specifications in Section 29.0 “Electrical Specifications”.
4: INTF is enabled to be set any time during the Q4-Q1 cycles.
(1)
(2)
(3)
(4)
(1)
2011 Microchip Technology Inc. Preliminary DS41609A-page 77
PIC16(L)F1508/9
7.3 Interrupts During Sleep
Some interrupts can be used to wake from Sleep. To
wake from Sleep, the peripheral must be able to
operate without the system clock. The interrupt source
must have the appropriate Interrupt Enable bit(s) set
prior to entering Sleep.
On waking from Sleep, if the GIE bit is also set, the
processor will branch to the interrupt vector. Otherwise,
the processor will continue executing instructions after
the SLEEP instruction. The instruction directly after the
SLEEP instruction will always be executed before
branching to the ISR. Refer to Section 8.0 “Power-
Down Mode (Sleep)” for more details.
7.4 INT Pin
The INT pin can be used to generate an asynchronous
edge-triggered interrupt. This interrupt is enabled by
setting the INTE bit of the INTCON register. The
INTEDG bit of the OPTION_REG register determines on
which edge the interrupt will occur. When the INTEDG
bit is set, the rising edge will cause the interrupt. When
the INTEDG bit is clear, the falling edge will cause the
interrupt. The INTF bit of the INTCON register will be set
when a valid edge appears on the INT pin. If the GIE and
INTE bits are also set, the processor will redirect
program execution to the interrupt vector.
7.5 Automatic Context Saving
Upon entering an interrupt, the return PC address is
saved on the stack. Additionally, the following registers
are automatically saved in the Shadow registers:
• W register
• STATUS register (except for TO and PD)
• BSR register
• FSR registers
• PCLATH register
Upon exiting the Interrupt Service Routine, these regis-
ters are automatically restored. Any modifications to
these registers during the ISR will be lost. If modifica-
tions to any of these registers are desired, the corre-
sponding Shadow register should be modified and the
value will be restored when exiting the ISR. The
Shadow registers are available in Bank 31 and are
readable and writable. Depending on the user’s appli-
cation, other registers may also need to be saved.
PIC16(L)F1508/9
DS41609A-page 78 Preliminary 2011 Microchip Technology Inc.
7.6 Interrupt Control Registers
7.6.1 INTCON REGISTER
The INTCON register is a readable and writable
register, that contains the various enable and flag bits
for TMR0 register overflow, interrupt-on-change and
external INT pin interrupts.
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, GIE, of the INTCON
register. User software should ensure the
appropriate interrupt flag bits are clear
prior to enabling an interrupt.
REGISTER 7-1: INTCON: INTERRUPT CONTROL REGISTER
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R-0/0
GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 GIE: Global Interrupt Enable bit
1 = Enables all active interrupts
0 = Disables all interrupts
bit 6 PEIE: Peripheral Interrupt Enable bit
1 = Enables all active peripheral interrupts
0 = Disables all peripheral interrupts
bit 5 TMR0IE: Timer0 Overflow Interrupt Enable bit
1 = Enables the Timer0 interrupt
0 = Disables the Timer0 interrupt
bit 4 INTE: INT External Interrupt Enable bit
1 = Enables the INT external interrupt
0 = Disables the INT external interrupt
bit 3 IOCIE: Interrupt-on-Change Enable bit
1 = Enables the interrupt-on-change
0 = Disables the interrupt-on-change
bit 2 TMR0IF: Timer0 Overflow Interrupt Flag bit
1 = TMR0 register has overflowed
0 = TMR0 register did not overflow
bit 1 INTF: INT External Interrupt Flag bit
1 = The INT external interrupt occurred
0 = The INT external interrupt did not occur
bit 0 IOCIF: Interrupt-on-Change Interrupt Flag bit(1)
1 = When at least one of the interrupt-on-change pins changed state
0 = None of the interrupt-on-change pins have changed state
Note 1: The IOCIF Flag bit is read-only and cleared when all the interrupt-on-change flags in the IOCBF register
have been cleared by software.
2011 Microchip Technology Inc. Preliminary DS41609A-page 79
PIC16(L)F1508/9
7.6.2 PIE1 REGISTER
The PIE1 register contains the interrupt enable bits, as
shown in Register 7-2.
Note: Bit PEIE of the INTCON register must be
set to enable any peripheral interrupt.
REGISTER 7-2: PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 U-0 R/W-0/0 R/W-0/0
TMR1GIE ADIE RCIE TXIE SSP1IE — TMR2IE TMR1IE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 TMR1GIE: Timer1 Gate Interrupt Enable bit
1 = Enables the Timer1 gate acquisition interrupt
0 = Disables the Timer1 gate acquisition interrupt
bit 6 ADIE: A/D Converter (ADC) Interrupt Enable bit
1 = Enables the ADC interrupt
0 = Disables the ADC interrupt
bit 5 RCIE: USART Receive Interrupt Enable bit
1 = Enables the USART receive interrupt
0 = Disables the USART receive interrupt
bit 4 TXIE: USART Transmit Interrupt Enable bit
1 = Enables the USART transmit interrupt
0 = Disables the USART transmit interrupt
bit 3 SSP1IE: Synchronous Serial Port (MSSP) Interrupt Enable bit
1 = Enables the MSSP interrupt
0 = Disables the MSSP interrupt
bit 2 Unimplemented: Read as ‘0’
bit 1 TMR2IE: TMR2 to PR2 Match Interrupt Enable bit
1 = Enables the Timer2 to PR2 match interrupt
0 = Disables the Timer2 to PR2 match interrupt
bit 0 TMR1IE: Timer1 Overflow Interrupt Enable bit
1 = Enables the Timer1 overflow interrupt
0 = Disables the Timer1 overflow interrupt
PIC16(L)F1508/9
DS41609A-page 80 Preliminary 2011 Microchip Technology Inc.
7.6.3 PIE2 REGISTER
The PIE2 register contains the interrupt enable bits, as
shown in Register 7-3.
Note: Bit PEIE of the INTCON register must be
set to enable any peripheral interrupt.
REGISTER 7-3: PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2
R/W-0/0 R/W-0/0 R/W-0/0 U-0 R/W-0/0 R/W-0/0 U-0 U-0
OSFIE C2IE C1IE — BCL1IE NCO1IE — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 OSFIE: Oscillator Fail Interrupt Enable bit
1 = Enables the Oscillator Fail interrupt
0 = Disables the Oscillator Fail interrupt
bit 6 C2IE: Comparator C2 Interrupt Enable bit
1 = Enables the Comparator C2 interrupt
0 = Disables the Comparator C2 interrupt
bit 5 C1IE: Comparator C1 Interrupt Enable bit
1 = Enables the Comparator C1 interrupt
0 = Disables the Comparator C1 interrupt
bit 4 Unimplemented: Read as ‘0’
bit 3 BCL1IE: MSSP Bus Collision Interrupt Enable bit
1 = Enables the MSSP Bus Collision Interrupt
0 = Disables the MSSP Bus Collision Interrupt
bit 2 NCO1IE: Numerically Controlled Oscillator Interrupt Enable bit
1 = Enables the NCO interrupt
0 = Disables the NCO interrupt
bit 1-0 Unimplemented: Read as ‘0’
2011 Microchip Technology Inc. Preliminary DS41609A-page 81
PIC16(L)F1508/9
7.6.4 PIE3 REGISTER
The PIE3 register contains the interrupt enable bits, as
shown in Register 7-4.
Note: Bit PEIE of the INTCON register must be
set to enable any peripheral interrupt.
REGISTER 7-4: PIE3: PERIPHERAL INTERRUPT ENABLE REGISTER 3
U-0 U-0 U-0 U-0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
— — — — CLC4IE CLC3IE CLC2IE CLC1IE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 Unimplemented: Read as ‘0’
bit 3 CLC4IE: Configurable Logic Block 4 Interrupt Enable bit
1 = Enables the CLC 4 interrupt
0 = Disables the CLC 4 interrupt
bit 2 CLC3IE: Configurable Logic Block 3 Interrupt Enable bit
1 = Enables the CLC 3 interrupt
0 = Disables the CLC 3 interrupt
bit 1 CLC2IE: Configurable Logic Block 2 Interrupt Enable bit
1 = Enables the CLC 2 interrupt
0 = Disables the CLC 2 interrupt
bit 0 CLC1IE: Configurable Logic Block 1 Interrupt Enable bit
1 = Enables the CLC 1 interrupt
0 = Disables the CLC 1 interrupt
PIC16(L)F1508/9
DS41609A-page 82 Preliminary 2011 Microchip Technology Inc.
7.6.5 PIR1 REGISTER
The PIR1 register contains the interrupt flag bits, as
shown in Register 7-5.
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, GIE, of the INTCON
register. User software should ensure the
appropriate interrupt flag bits are clear prior
to enabling an interrupt.
REGISTER 7-5: PIR1: PERIPHERAL INTERRUPT REQUEST REGISTER 1
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 U-0 R/W-0/0 R/W-0/0
TMR1GIF ADIF RCIF TXIF SSP1IF — TMR2IF TMR1IF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 TMR1GIF: Timer1 Gate Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 6 ADIF: A/D Converter Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 5 RCIF: USART Receive Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 4 TXIF: USART Transmit Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 3 SSP1IF: Synchronous Serial Port (MSSP) Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 2 Unimplemented: Read as ‘0’
bit 1 TMR2IF: Timer2 to PR2 Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 0 TMR1IF: Timer1 Overflow Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
2011 Microchip Technology Inc. Preliminary DS41609A-page 83
PIC16(L)F1508/9
7.6.6 PIR2 REGISTER
The PIR2 register contains the interrupt flag bits, as
shown in Register 7-6.
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, GIE, of the INTCON
register. User software should ensure the
appropriate interrupt flag bits are clear prior
to enabling an interrupt.
REGISTER 7-6: PIR2: PERIPHERAL INTERRUPT REQUEST REGISTER 2
R/W-0/0 R/W-0/0 R/W-0/0 U-0 R/W-0/0 R/W-0/0 U-0 U-0
OSFIF C2IF C1IF — BCL1IF NCO1IF — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 OSFIF: Oscillator Fail Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 6 C2IF: Numerically Controlled Oscillator Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 5 C1IF: Numerically Controlled Oscillator Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 4 Unimplemented: Read as ‘0’
bit 3 BCL1IF: MSSP Bus Collision Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 2 NCO1IF: Numerically Controlled Oscillator Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 1-0 Unimplemented: Read as ‘0’
PIC16(L)F1508/9
DS41609A-page 84 Preliminary 2011 Microchip Technology Inc.
7.6.7 PIR3 REGISTER
The PIR3 register contains the interrupt flag bits, as
shown in Register 7-7.
Note: Interrupt flag bits are set when an interrupt
condition occurs, regardless of the state of
its corresponding enable bit or the Global
Enable bit, GIE, of the INTCON register.
User software should ensure the
appropriate interrupt flag bits are clear prior
to enabling an interrupt.
REGISTER 7-7: PIR3: PERIPHERAL INTERRUPT REQUEST REGISTER 3
U-0 U-0 U-0 U-0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
— — — — CLC4IF CLC3IF CLC2IF CLC1IF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 Unimplemented: Read as ‘0’
bit 3 CLC4IF: Configurable Logic Block 4 Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 2 CLC3IF: Configurable Logic Block 3 Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 1 CLC2IF: Configurable Logic Block 2 Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
bit 0 CLC1IF: Configurable Logic Block 1 Interrupt Flag bit
1 = Interrupt is pending
0 = Interrupt is not pending
2011 Microchip Technology Inc. Preliminary DS41609A-page 85
PIC16(L)F1508/9
TABLE 7-1: SUMMARY OF REGISTERS ASSOCIATED WITH INTERRUPTS
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
OPTION_REG WPUEN INTEDG TMR0CS TMR0SE PSA PS<2:0> 165
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE — TMR2IE TMR1IE 79
PIE2 OSFIE C2IE C1IE — BCL1IE NCO1IE — — 80
PIE3 — — — — CLC4IE CLC4IE CLC2IE CLC1IE 81
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF — TMR2IF TMR1IF 82
PIR2 OSFIF C2IF C1IF — BCL1IF NCO1IF — — 83
PIR3 — — — — CLC4IF CLC3IF CLC2IF CLC1IF 84
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by interrupts.
PIC16(L)F1508/9
DS41609A-page 86 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 87
PIC16(L)F1508/9
8.0 POWER-DOWN MODE (SLEEP)
The Power-Down mode is entered by executing a
SLEEP instruction.
Upon entering Sleep mode, the following conditions exist:
1. WDT will be cleared but keeps running, if
enabled for operation during Sleep.
2. PD bit of the STATUS register is cleared.
3. TO bit of the STATUS register is set.
4. CPU clock is disabled.
5. 31 kHz LFINTOSC is unaffected and peripherals
that operate from it may continue operation in
Sleep.
6. ADC is unaffected, if the dedicated FRC clock is
selected.
7. I/O ports maintain the status they had before
SLEEP was executed (driving high, low or high-
impedance).
8. Resets other than WDT are not affected by
Sleep mode.
Refer to individual chapters for more details on
peripheral operation during Sleep.
To minimize current consumption, the following
conditions should be considered:
• I/O pins should not be floating
• External circuitry sinking current from I/O pins
• Internal circuitry sourcing current from I/O pins
• Current draw from pins with internal weak pull-ups
• Modules using 31 kHz LFINTOSC
• CWG, NCO and CLC modules using HFINTOSC
I/O pins that are high-impedance inputs should be
pulled to VDD or VSS externally to avoid switching
currents caused by floating inputs.
Examples of internal circuitry that might be sourcing
current include the FVR module. See Section 13.0
“Fixed Voltage Reference (FVR)” for more
information on this module.
8.1 Wake-up from Sleep
The device can wake-up from Sleep through one of the
following events:
1. External Reset input on MCLR pin, if enabled
2. BOR Reset, if enabled
3. POR Reset
4. Watchdog Timer, if enabled
5. Any external interrupt
6. Interrupts by peripherals capable of running dur-
ing Sleep (see individual peripheral for more
information)
The first three events will cause a device Reset. The
last three events are considered a continuation of pro-
gram execution. To determine whether a device Reset
or wake-up event occurred, refer to Section 6.11
“Determining the Cause of a Reset”.
When the SLEEP instruction is being executed, the next
instruction (PC + 1) is prefetched. For the device to
wake-up through an interrupt event, the corresponding
interrupt enable bit must be enabled. Wake-up will
occur regardless of the state of the GIE bit. If the GIE
bit is disabled, the device continues execution at the
instruction after the SLEEP instruction. If the GIE bit is
enabled, the device executes the instruction after the
SLEEP instruction, the device will then call the Interrupt
Service Routine. In cases where the execution of the
instruction following SLEEP is not desirable, the user
should have a NOP after the SLEEP instruction.
The WDT is cleared when the device wakes up from
Sleep, regardless of the source of wake-up.
8.1.1 WAKE-UP USING INTERRUPTS
When global interrupts are disabled (GIE cleared) and
any interrupt source has both its interrupt enable bit
and interrupt flag bit set, one of the following will occur:
• If the interrupt occurs before the execution of a
SLEEP instruction
-SLEEP instruction will execute as a NOP.
- WDT and WDT prescaler will not be cleared
-TO
bit of the STATUS register will not be set
-PD bit of the STATUS register will not be
cleared.
• If the interrupt occurs during or after the execu-
tion of a SLEEP instruction
-SLEEP instruction will be completely exe-
cuted
- Device will immediately wake-up from Sleep
- WDT and WDT prescaler will be cleared
-TO
bit of the STATUS register will be set
-PD bit of the STATUS register will be cleared
PIC16(L)F1508/9
DS41609A-page 88 Preliminary 2011 Microchip Technology Inc.
Even if the flag bits were checked before executing a
SLEEP instruction, it may be possible for flag bits to
become set before the SLEEP instruction completes. To
determine whether a SLEEP instruction executed, test
the PD bit. If the PD bit is set, the SLEEP instruction
was executed as a NOP.
FIGURE 8-1: WAKE-UP FROM SLEEP THROUGH INTERRUPT
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
CLKIN(1)
CLKOUT(2)
Interrupt flag
GIE bit
(INTCON reg.)
Instruction Flow
PC
Instruction
Fetched
Instruction
Executed
PC PC + 1 PC + 2
Inst(PC) = Sleep
Inst(PC - 1)
Inst(PC + 1)
Sleep
Processor in
Sleep
Interrupt Latency(4)
Inst(PC + 2)
Inst(PC + 1)
Inst(0004h) Inst(0005h)
Inst(0004h)
Forced NOP
PC + 2 0004h 0005h
Forced NOP
T1OSC(3)
PC + 2
Note 1: External clock. High, Medium, Low mode assumed.
2: CLKOUT is shown here for timing reference.
3: T1OSC; See Section 29.0 “Electrical Specifications”.
4: GIE = 1 assumed. In this case after wake-up, the processor calls the ISR at 0004h. If GIE = 0, execution will continue in-line.
2011 Microchip Technology Inc. Preliminary DS41609A-page 89
PIC16(L)F1508/9
8.2 Low-Power Sleep Mode
The PIC16F1508/9 device contains an internal Low
Dropout (LDO) voltage regulator, which allows the
device I/O pins to operate at voltages up to 5.5V while
the internal device logic operates at a lower voltage.
The LDO and its associated reference circuitry must
remain active when the device is in Sleep mode. The
PIC16F1508/9 allows the user to optimize the
operating current in Sleep, depending on the
application requirements.
A Low-Power Sleep mode can be selected by setting
the VREGPM bit of the VREGCON register. With this
bit set, the LDO and reference circuitry are placed in a
low-power state when the device is in Sleep.
8.2.1 SLEEP CURRENT VS. WAKE-UP
TIME
In the default operating mode, the LDO and reference
circuitry remain in the normal configuration while in
Sleep. The device is able to exit Sleep mode quickly
since all circuits remain active. In Low-Power Sleep
mode, when waking up from Sleep, an extra delay time
is required for these circuits to return to the normal con-
figuration and stabilize.
The Low-Power Sleep mode is beneficial for applica-
tions that stay in Sleep mode for long periods of time.
The Normal mode is beneficial for applications that
need to wake from Sleep quickly and frequently.
8.2.2 PERIPHERAL USAGE IN SLEEP
Some peripherals that can operate in Sleep mode will
not operate properly with the Low-Power Sleep mode
selected. The LDO will remain in the Normal Power
mode when those peripherals are enabled. The Low-
Power Sleep mode is intended for use with these
peripherals:
• Brown-Out Reset (BOR)
• Watchdog Timer (WDT)
• External interrupt pin/Interrupt-on-change pins
• Timer1 (with external clock source)
The Complementary Waveform Generator (CWG), the
Numerically Controlled Oscillator (NCO) and the Con-
figurable Logic Cell (CLC) modules can utilize the
HFINTOSC oscillator as either a clock source or as an
input source. Under certain conditions, when the
HFINTOSC is selected for use with the CWG, NCO or
CLC modules, the HFINTOSC will remain active
during Sleep. This will have a direct effect on the
Sleep mode current.
Please refer to sections 24.5 “Operation During
Sleep”, 25.7 “Operation In Sleep” and 26.10 “Oper-
ation During Sleep” for more information.
Note: The PIC16LF1508/9 does not have a con-
figurable Low-Power Sleep mode.
PIC16LF1508/9 is an unregulated device
and is always in the lowest power state
when in Sleep, with no wake-up time pen-
alty. This device has a lower maximum
VDD and I/O voltage than the
PIC16F1508/9. See Section 29.0 “Elec-
trical Specifications” for more informa-
tion.
PIC16(L)F1508/9
DS41609A-page 90 Preliminary 2011 Microchip Technology Inc.
TABLE 8-1: SUMMARY OF REGISTERS ASSOCIATED WITH POWER-DOWN MODE
REGISTER 8-1: VREGCON: VOLTAGE REGULATOR CONTROL REGISTER(1)
U-0 U-0 U-0 U-0 U-0 U-0 R/W-0/0 R/W-1/1
— — — — — —VREGPMReserved
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-2 Unimplemented: Read as ‘0’
bit 1 VREGPM: Voltage Regulator Power Mode Selection bit
1 = Low-Power Sleep mode enabled in Sleep
Draws lowest current in Sleep, slower wake-up
0 = Normal Power mode enabled in Sleep
Draws higher current in Sleep, faster wake-up
bit 0 Reserved: Read as ‘1’. Maintain this bit set.
Note 1: PIC16F1508/9 only.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register on
Page
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
IOCAF —— IOCAF5 IOCAF4 IOCAF3 IOCAF2 IOCAF1 IOCAF0 127
IOCAN —— IOCAN5 IOCAN4 IOCAN3 IOCAN2 IOCAN1 IOCAN0 127
IOCAP —— IOCAP5 IOCAP4 IOCAP3 IOCAP2 IOCAP1 IOCAP0 127
IOCBF IOCBF7 IOCBF6 IOCBF5 IOCBF4 — — — — 128
IOCBN IOCBN7 IOCBN6 IOCBN5 IOCBN4 — — — — 128
IOCBP IOCBP7 IOCBP6 IOCBP5 IOCBP4 — — — — 128
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE — TMR2IE TMR1IE 79
PIE2 OSFIE C2IE C1IE — BCL1IE NCO1IE — — 80
PIE3 ———— CLC4IE CLC4IE CLC2IE CLC1IE 81
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF — TMR2IF TMR1IF 82
PIR2 OSFIF C2IF C1IF — BCL1IF NCO1IF — — 83
PIR3 ———— CLC4IF CLC3IF CLC2IF CLC1IF 84
STATUS — — —TOPD ZDC C21
WDTCON —— WDTPS<4:0> SWDTEN 93
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used in Power-Down mode.
2011 Microchip Technology Inc. Preliminary DS41609A-page 91
PIC16(L)F1508/9
9.0 WATCHDOG TIMER
The Watchdog Timer is a system timer that generates
a Reset if the firmware does not issue a CLRWDT
instruction within the time-out period. The Watchdog
Timer is typically used to recover the system from
unexpected events.
The WDT has the following features:
• Independent clock source
• Multiple operating modes
- WDT is always on
- WDT is off when in Sleep
- WDT is controlled by software
- WDT is always off
• Configurable time-out period is from 1 ms to 256
seconds (typical)
• Multiple Reset conditions
• Operation during Sleep
FIGURE 9-1: WATCHDOG TIMER BLOCK DIAGRAM
LFINTOSC 23-bit Programmable
Prescaler WDT WDT Time-out
WDTPS<4:0>
SWDTEN
Sleep
WDTE<1:0> = 11
WDTE<1:0> = 01
WDTE<1:0> = 10
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DS41609A-page 92 Preliminary 2011 Microchip Technology Inc.
9.1 Independent Clock Source
The WDT derives its time base from the 31 kHz
LFINTOSC internal oscillator. Time intervals in this
chapter are based on a nominal interval of 1 ms. See
Section 29.0 “Electrical Specifications” for the
LFINTOSC tolerances.
9.2 WDT Operating Modes
The Watchdog Timer module has four operating modes
controlled by the WDTE<1:0> bits in Configuration
Words. See Tabl e 9-1 .
9.2.1 WDT IS ALWAYS ON
When the WDTE bits of Configuration Words are set to
‘11’, the WDT is always on.
WDT protection is active during Sleep.
9.2.2 WDT IS OFF IN SLEEP
When the WDTE bits of Configuration Words are set to
‘10’, the WDT is on, except in Sleep.
WDT protection is not active during Sleep.
9.2.3 WDT CONTROLLED BY SOFTWARE
When the WDTE bits of Configuration Words are set to
‘01’, the WDT is controlled by the SWDTEN bit of the
WDTCON register.
WDT protection is unchanged by Sleep. See Table 9-1
for more details.
TABLE 9-1: WDT OPERATING MODES
9.3 Time-Out Period
The WDTPS bits of the WDTCON register set the
time-out period from 1 ms to 256 seconds (nominal).
After a Reset, the default time-out period is 2 seconds.
9.4 Clearing the WDT
The WDT is cleared when any of the following condi-
tions occur:
•Any Reset
•CLRWDT instruction is executed
• Device enters Sleep
• Device wakes up from Sleep
• Oscillator fail
• WDT is disabled
See Table 9-2 for more information.
9.5 Operation During Sleep
When the device enters Sleep, the WDT is cleared. If
the WDT is enabled during Sleep, the WDT resumes
counting.
When the device exits Sleep, the WDT is cleared
again. The WDT remains clear until the OST, if
enabled, completes. See Section 5.0 “Oscillator
Module (With Fail-Safe Clock Monitor)” for more
information on the OST.
When a WDT time-out occurs while the device is in
Sleep, no Reset is generated. Instead, the device
wakes up and resumes operation. The TO and PD bits
in the STATUS register are changed to indicate the
event. The RWDT bit in the PCON register can also be
used. See Section 3.0 “Memory Organization” for
more information.
WDTE<1:0> SWDTEN Device
Mode
WDT
Mode
11 X XActive
10 X
Awake Active
Sleep Disabled
01 1XActive
0Disabled
00 X X Disabled
TABLE 9-2: WDT CLEARING CONDITIONS
Conditions WDT
WDTE<1:0> = 00
Cleared
WDTE<1:0> = 01 and SWDTEN = 0
WDTE<1:0> = 10 and enter Sleep
CLRWDT Command
Oscillator Fail Detected
Exit Sleep + System Clock = INTOSC, EXTCLK
Change INTOSC divider (IRCF bits) Unaffected
2011 Microchip Technology Inc. Preliminary DS41609A-page 93
PIC16(L)F1508/9
9.6 Watchdog Control Register
REGISTER 9-1: WDTCON: WATCHDOG TIMER CONTROL REGISTER
U-0 U-0 R/W-0/0 R/W-1/1 R/W-0/0 R/W-1/1 R/W-1/1 R/W-0/0
—— WDTPS<4:0> SWDTEN
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 Unimplemented: Read as ‘0’
bit 5-1 WDTPS<4:0>: Watchdog Timer Period Select bits(1)
Bit Value = Prescale Rate
00000 = 1:32 (Interval 1 ms nominal)
00001 = 1:64 (Interval 2 ms nominal)
00010 = 1:128 (Interval 4 ms nominal)
00011 = 1:256 (Interval 8 ms nominal)
00100 = 1:512 (Interval 16 ms nominal)
00101 = 1:1024 (Interval 32 ms nominal)
00110 = 1:2048 (Interval 64 ms nominal)
00111 = 1:4096 (Interval 128 ms nominal)
01000 = 1:8192 (Interval 256 ms nominal)
01001 = 1:16384 (Interval 512 ms nominal)
01010 = 1:32768 (Interval 1s nominal)
01011 = 1:65536 (Interval 2s nominal) (Reset value)
01100 = 1:131072 (217) (Interval 4s nominal)
01101 = 1:262144 (218) (Interval 8s nominal)
01110 = 1:524288 (219) (Interval 16s nominal)
01111 = 1:1048576 (220) (Interval 32s nominal)
10000 = 1:2097152 (221) (Interval 64s nominal)
10001 = 1:4194304 (222) (Interval 128s nominal)
10010 = 1:8388608 (223) (Interval 256s nominal)
10011 = Reserved. Results in minimum interval (1:32)
•
•
•
11111 = Reserved. Results in minimum interval (1:32)
bit 0 SWDTEN: Software Enable/Disable for Watchdog Timer bit
If WDTE<1:0> = 00:
This bit is ignored.
If WDTE<1:0> = 01:
1 = WDT is turned on
0 = WDT is turned off
If WDTE<1:0> = 1x:
This bit is ignored.
Note 1: Times are approximate. WDT time is based on 31 kHz LFINTOSC.
PIC16(L)F1508/9
DS41609A-page 94 Preliminary 2011 Microchip Technology Inc.
TABLE 9-3: SUMMARY OF REGISTERS ASSOCIATED WITH WATCHDOG TIMER
TABLE 9-4: SUMMARY OF CONFIGURATION WORD WITH WATCHDOG TIMER
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
OSCCON — IRCF<3:0> —SCS<1:0>
62
PCON STKOVF STKUNF —RWDTRMCLR RI POR BOR 71
STATUS ———TOPD ZDC C21
WDTCON —— WDTPS<4:0> SWDTEN 93
Legend: x = unknown, u = unchanged, – = unimplemented locations read as ‘0’. Shaded cells are not used by Watchdog Timer.
Name Bits Bit -/7 Bit -/6 Bit 13/5 Bit 12/4 Bit 11/3 Bit 10/2 Bit 9/1 Bit 8/0 Register
on Page
CONFIG1 13:8 — — FCMEN IESO CLKOUTEN BOREN<1:0> —44
7:0 CP MCLRE PWRTE WDTE<1:0> FOSC<2:0>
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by Watchdog Timer.
2011 Microchip Technology Inc. Preliminary DS41609A-page 95
PIC16(L)F1508/9
10.0 FLASH PROGRAM MEMORY
CONTROL
The Flash program memory is readable and writable
during normal operation over the full VDD range.
Program memory is indirectly addressed using Special
Function Registers (SFRs). The SFRs used to access
program memory are:
•PMCON1
•PMCON2
•PMDATL
•PMDATH
• PMADRL
•PMADRH
When accessing the program memory, the
PMDATH:PMDATL register pair forms a 2-byte word
that holds the 14-bit data for read/write, and the
PMADRH:PMADRL register pair forms a 2-byte word
that holds the 15-bit address of the program memory
location being read.
The write time is controlled by an on-chip timer. The write/
erase voltages are generated by an on-chip charge
pump.
The Flash program memory can be protected in two
ways; by code protection (CP bit in Configuration Words)
and write protection (WRT<1:0> bits in Configuration
Words).
Code protection (CP = 0)(1), disables access, reading
and writing, to the Flash program memory via external
device programmers. Code protection does not affect
the self-write and erase functionality. Code protection
can only be reset by a device programmer performing
a Bulk Erase to the device, clearing all Flash program
memory, Configuration bits and User IDs.
Write protection prohibits self-write and erase to a
portion or all of the Flash program memory as defined
by the bits WRT<1:0>. Write protection does not affect
a device programmers ability to read, write or erase the
device.
10.1 PMADRL and PMADRH Registers
The PMADRH:PMADRL register pair can address up
to a maximum of 32K words of program memory. When
selecting a program address value, the MSB of the
address is written to the PMADRH register and the LSB
is written to the PMADRL register.
10.1.1 PMCON1 AND PMCON2
REGISTERS
PMCON1 is the control register for Flash program
memory accesses.
Control bits RD and WR initiate read and write,
respectively. These bits cannot be cleared, only set, in
software. They are cleared by hardware at completion
of the read or write operation. The inability to clear the
WR bit in software prevents the accidental, premature
termination of a write operation.
The WREN bit, when set, will allow a write operation to
occur. On power-up, the WREN bit is clear. The
WRERR bit is set when a write operation is interrupted
by a Reset during normal operation. In these situations,
following Reset, the user can check the WRERR bit
and execute the appropriate error handling routine.
The PMCON2 register is a write-only register. Attempting
to read the PMCON2 register will return all ‘0’s.
To enable writes to the program memory, a specific
pattern (the unlock sequence), must be written to the
PMCON2 register. The required unlock sequence
prevents inadvertent writes to the program memory
write latches and Flash program memory.
10.2 Flash Program Memory Overview
It is important to understand the Flash program memory
structure for erase and programming operations. Flash
program memory is arranged in rows. A row consists of
a fixed number of 14-bit program memory words. A row
is the minimum size that can be erased by user software.
After a row has been erased, the user can reprogram
all or a portion of this row. Data to be written into the
program memory row is written to 14-bit wide data write
latches. These write latches are not directly accessible
to the user, but may be loaded via sequential writes to
the PMDATH:PMDATL register pair.
See Table 10-1 for Erase Row size and the number of
write latches for Flash program memory.
Note 1: Code protection of the entire Flash
program memory array is enabled by
clearing the CP bit of Configuration Words.
Note: If the user wants to modify only a portion
of a previously programmed row, then the
contents of the entire row must be read
and saved in RAM prior to the erase.
Then, new data and retained data can be
written into the write latches to reprogram
the row of Flash program memory. How-
ever, any unprogrammed locations can be
written without first erasing the row. In this
case, it is not necessary to save and
rewrite the other previously programmed
locations.
TABLE 10-1: FLASH MEMORY
ORGANIZATION BY DEVICE
Device Row Erase
(words)
Write
Latches
(words)
PIC16(L)F1508 32 32
PIC16(L)F1509
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DS41609A-page 96 Preliminary 2011 Microchip Technology Inc.
10.2.1 READING THE FLASH PROGRAM
MEMORY
To read a program memory location, the user must:
1. Write the desired address to the
PMADRH:PMADRL register pair.
2. Clear the CFGS bit of the PMCON1 register.
3. Then, set control bit RD of the PMCON1 register.
Once the read control bit is set, the program memory
Flash controller will use the second instruction cycle to
read the data. This causes the second instruction
immediately following the “BSF PMCON1,RD” instruction
to be ignored. The data is available in the very next cycle,
in the PMDATH:PMDATL register pair; therefore, it can
be read as two bytes in the following instructions.
PMDATH:PMDATL register pair will hold this value until
another read or until it is written to by the user.
FIGURE 10-1: FLASH PROGRAM
MEMORY READ
FLOWCHART
Note: The two instructions following a program
memory read are required to be NOPs.
This prevents the user from executing a
two-cycle instruction on the next
instruction after the RD bit is set.
Start
Read Operation
Select
Program or Configuration Memory
(CFGS)
Select
Word Address
(PMADRH:PMADRL)
End
Read Operation
Instruction Fetched ignored
NOP execution forced
Instruction Fetched ignored
NOP execution forced
Initiate Read operation
(RD = 1)
Data read now in
PMDATH:PMDATL
2011 Microchip Technology Inc. Preliminary DS41609A-page 97
PIC16(L)F1508/9
FIGURE 10-2: FLASH PROGRAM MEMORY READ CYCLE EXECUTION
EXAMPLE 10-1: FLASH PROGRAM MEMORY READ
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
BSF PMCON1,RD
executed here
INSTR(PC + 1)
executed here
PC
PC + 1 PMADRH,PMADRL PC+3 PC + 5
Flash ADDR
RD bit
PMDATH,PMDATL
PC + 3 PC + 4
INSTR (PC + 1)
INSTR(PC - 1)
executed here INSTR(PC + 3)
executed here INSTR(PC + 4)
executed here
Flash Data
PMDATH
PMDATL
Register
INSTR (PC) INSTR (PC + 3) INSTR (PC + 4)
instruction ignored
Forced NOP
INSTR(PC + 2)
executed here
instruction ignored
Forced NOP
* This code block will read 1 word of program
* memory at the memory address:
PROG_ADDR_HI : PROG_ADDR_LO
* data will be returned in the variables;
* PROG_DATA_HI, PROG_DATA_LO
BANKSEL PMADRL ; Select Bank for PMCON registers
MOVLW PROG_ADDR_LO ;
MOVWF PMADRL ; Store LSB of address
MOVLW PROG_ADDR_HI ;
MOVWF PMADRH ; Store MSB of address
BCF PMCON1,CFGS ; Do not select Configuration Space
BSF PMCON1,RD ; Initiate read
NOP ; Ignored (Figure 10-2)
NOP ; Ignored (Figure 10-2)
MOVF PMDATL,W ; Get LSB of word
MOVWF PROG_DATA_LO ; Store in user location
MOVF PMDATH,W ; Get MSB of word
MOVWF PROG_DATA_HI ; Store in user location
PIC16(L)F1508/9
DS41609A-page 98 Preliminary 2011 Microchip Technology Inc.
10.2.2 FLASH MEMORY UNLOCK
SEQUENCE
The unlock sequence is a mechanism that protects the
Flash program memory from unintended self-write pro-
gramming or erasing. The sequence must be executed
and completed without interruption to successfully
complete any of the following operations:
•Row Erase
• Load program memory write latches
• Write of program memory write latches to pro-
gram memory
• Write of program memory write latches to User
IDs
The unlock sequence consists of the following steps:
1. Write 55h to PMCON2
2. Write AAh to PMCON2
3. Set the WR bit in PMCON1
4. NOP instruction
5. NOP instruction
Once the WR bit is set, the processor will always force
two NOP instructions. When an Erase Row or Program
Row operation is being performed, the processor will stall
internal operations (typical 2 ms), until the operation is
complete and then resume with the next instruction.
When the operation is loading the program memory write
latches, the processor will always force the two NOP
instructions and continue uninterrupted with the next
instruction.
Since the unlock sequence must not be interrupted,
global interrupts should be disabled prior to the unlock
sequence and re-enabled after the unlock sequence is
completed.
FIGURE 10-3: FLASH PROGRAM
MEMORY UNLOCK
SEQUENCE FLOWCHART
Write 055h to
PMCON2
Start
Unlock Sequence
Write 0AAh to
PMCON2
Initiate
Write or Erase operation
(WR = 1)
Instruction Fetched ignored
NOP execution forced
End
Unlock Sequence
Instruction Fetched ignored
NOP execution forced
2011 Microchip Technology Inc. Preliminary DS41609A-page 99
PIC16(L)F1508/9
10.2.3 ERASING FLASH PROGRAM
MEMORY
While executing code, program memory can only be
erased by rows. To erase a row:
1. Load the PMADRH:PMADRL register pair with
any address within the row to be erased.
2. Clear the CFGS bit of the PMCON1 register.
3. Set the FREE and WREN bits of the PMCON1
register.
4. Write 55h, then AAh, to PMCON2 (Flash
programming unlock sequence).
5. Set control bit WR of the PMCON1 register to
begin the erase operation.
See Example 10-2.
After the “BSF PMCON1,WR” instruction, the processor
requires two cycles to set up the erase operation. The
user must place two NOP instructions immediately fol-
lowing the WR bit set instruction. The processor will
halt internal operations for the typical 2 ms erase time.
This is not Sleep mode as the clocks and peripherals
will continue to run. After the erase cycle, the processor
will resume operation with the third instruction after the
PMCON1 write instruction.
FIGURE 10-4: FLASH PROGRAM
MEMORY ERASE
FLOWCHART
Disable Interrupts
(GIE = 0)
Start
Erase Operation
Select
Program or Configuration Memory
(CFGS)
Select Row Address
(PMADRH:PMADRL)
Select Erase Operation
(FREE = 1)
Enable Write/Erase Operation
(WREN = 1)
Unlock Sequence
(FIGURE x-x)
Disable Write/Erase Operation
(WREN = 0)
Re-enable Interrupts
(GIE = 1)
End
Erase Operation
CPU stalls while
Erase operation completes
(2ms typical)
Figure 10-3
PIC16(L)F1508/9
DS41609A-page 100 Preliminary 2011 Microchip Technology Inc.
EXAMPLE 10-2: ERASING ONE ROW OF PROGRAM MEMORY
; This row erase routine assumes the following:
; 1. A valid address within the erase row is loaded in ADDRH:ADDRL
; 2. ADDRH and ADDRL are located in shared data memory 0x70 - 0x7F (common RAM)
BCF INTCON,GIE ; Disable ints so required sequences will execute properly
BANKSEL PMADRL
MOVF ADDRL,W ; Load lower 8 bits of erase address boundary
MOVWF PMADRL
MOVF ADDRH,W ; Load upper 6 bits of erase address boundary
MOVWF PMADRH
BCF PMCON1,CFGS ; Not configuration space
BSF PMCON1,FREE ; Specify an erase operation
BSF PMCON1,WREN ; Enable writes
MOVLW 55h ; Start of required sequence to initiate erase
MOVWF PMCON2 ; Write 55h
MOVLW 0AAh ;
MOVWF PMCON2 ; Write AAh
BSF PMCON1,WR ; Set WR bit to begin erase
NOP ; NOP instructions are forced as processor starts
NOP ; row erase of program memory.
;
; The processor stalls until the erase process is complete
; after erase processor continues with 3rd instruction
BCF PMCON1,WREN ; Disable writes
BSF INTCON,GIE ; Enable interrupts
Required
Sequence
2011 Microchip Technology Inc. Preliminary DS41609A-page 101
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10.2.4 WRITING TO FLASH PROGRAM
MEMORY
Program memory is programmed using the following
steps:
1. Load the address in PMADRH:PMADRL of the
row to be programmed.
2. Load each write latch with data.
3. Initiate a programming operation.
4. Repeat steps 1 through 3 until all data is written.
Before writing to program memory, the word(s) to be
written must be erased or previously unwritten. Pro-
gram memory can only be erased one row at a time. No
automatic erase occurs upon the initiation of the write.
Program memory can be written one or more words at
a time. The maximum number of words written at one
time is equal to the number of write latches. See
Figure 10-5 (row writes to program memory with 32
write latches) for more details.
The write latches are aligned to the Flash row address
boundary defined by the upper 10-bits of
PMADRH:PMADRL, (PMADRH<6:0>:PMADRL<7:5>)
with the lower 5-bits of PMADRL, (PMADRL<4:0>)
determining the write latch being loaded. Write opera-
tions do not cross these boundaries. At the completion
of a program memory write operation, the data in the
write latches is reset to contain 0x3FFF.
The following steps should be completed to load the
write latches and program a row of program memory.
These steps are divided into two parts. First, each write
latch is loaded with data from the PMDATH:PMDATL
using the unlock sequence with LWLO = 1. When the
last word to be loaded into the write latch is ready, the
LWLO bit is cleared and the unlock sequence
executed. This initiates the programming operation,
writing all the latches into Flash program memory.
1. Set the WREN bit of the PMCON1 register.
2. Clear the CFGS bit of the PMCON1 register.
3. Set the LWLO bit of the PMCON1 register.
When the LWLO bit of the PMCON1 register is
‘1’, the write sequence will only load the write
latches and will not initiate the write to Flash
program memory.
4. Load the PMADRH:PMADRL register pair with
the address of the location to be written.
5. Load the PMDATH:PMDATL register pair with
the program memory data to be written.
6. Execute the unlock sequence (Section 10.2.2
“Flash Memory Unlock Sequence”). The write
latch is now loaded.
7. Increment the PMADRH:PMADRL register pair
to point to the next location.
8. Repeat steps 5 through 7 until all but the last
write latch has been loaded.
9. Clear the LWLO bit of the PMCON1 register.
When the LWLO bit of the PMCON1 register is
‘0’, the write sequence will initiate the write to
Flash program memory.
10. Load the PMDATH:PMDATL register pair with
the program memory data to be written.
11. Execute the unlock sequence (Section 10.2.2
“Flash Memory Unlock Sequence”). The
entire program memory latch content is now
written to Flash program memory.
An example of the complete write sequence is shown in
Example 10-3. The initial address is loaded into the
PMADRH:PMADRL register pair; the data is loaded
using indirect addressing.
Note: The special unlock sequence is required
to load a write latch with data or initiate a
Flash programming operation. If the
unlock sequence is interrupted, writing to
the latches or program memory will not be
initiated.
Note: The program memory write latches are
reset to the blank state (0x3FFF) at the
completion of every write or erase
operation. As a result, it is not necessary
to load all the program memory write
latches. Unloaded latches will remain in
the blank state.
PIC16(L)F1508/9
DS41609A-page 102 Preliminary 2011 Microchip Technology Inc.
FIGURE 10-5: BLOCK WRITES TO FLASH PROGRAM MEMORY WITH 32 WRITE LATCHES
PMDATH PMDATL
7 5 0 7 0
6 8
14
1414
Write Latch #31
1Fh
1414
PMADRH PMADRL
7 6 0 7 5 4 0
Program Memory Write Latches
14 14 14
510
PMADRH<6:0>
:PMADRL<7:5> Flash Program Memory
Row
Row
Address
Decode
Addr
Write Latch #30
1Eh
Write Latch #1
01h
Write Latch #0
00h
Addr AddrAddr
000h 001Fh001Eh0000h 0001h
001h 003Fh003Eh0020h 0021h
002h 005Fh005Eh0040h 0041h
3FEh 7FDFh7FDEh7FC0h 7FC1h
3FFh 7FFFh7FFEh7FE0h 7FE1h
14
r9 r8 r7 r6 r5 r4 r3-r1 r0 c4 c3 c2 c1 c0r2
PMADRL<4:0>
400h 8009h - 801Fh8000h - 8003h
Configuration
Words
USER ID 0 - 3
8007h - 8008h8006h
DEVICEID
REVID
reserved
8004h - 8005h
reserved
Configuration Memory
CFGS = 0
CFGS = 1
--
2011 Microchip Technology Inc. Preliminary DS41609A-page 103
PIC16(L)F1508/9
FIGURE 10-6: FLASH PROGRAM MEMORY WRITE FLOWCHART
Figure 10-3
Figure 10-3
PIC16(L)F1508/9
DS41609A-page 104 Preliminary 2011 Microchip Technology Inc.
EXAMPLE 10-3: WRITING TO FLASH PROGRAM MEMORY
; This write routine assumes the following:
; 1. 64 bytes of data are loaded, starting at the address in DATA_ADDR
; 2. Each word of data to be written is made up of two adjacent bytes in DATA_ADDR,
; stored in little endian format
; 3. A valid starting address (the least significant bits = 00000) is loaded in ADDRH:ADDRL
; 4. ADDRH and ADDRL are located in shared data memory 0x70 - 0x7F (common RAM)
;
BCF INTCON,GIE ; Disable ints so required sequences will execute properly
BANKSEL PMADRH ; Bank 3
MOVF ADDRH,W ; Load initial address
MOVWF PMADRH ;
MOVF ADDRL,W ;
MOVWF PMADRL ;
MOVLW LOW DATA_ADDR ; Load initial data address
MOVWF FSR0L ;
MOVLW HIGH DATA_ADDR ; Load initial data address
MOVWF FSR0H ;
BCF PMCON1,CFGS ; Not configuration space
BSF PMCON1,WREN ; Enable writes
BSF PMCON1,LWLO ; Only Load Write Latches
LOOP
MOVIW FSR0++ ; Load first data byte into lower
MOVWF PMDATL ;
MOVIW FSR0++ ; Load second data byte into upper
MOVWF PMDATH ;
MOVF PMADRL,W ; Check if lower bits of address are '00000'
XORLW 0x1F ; Check if we're on the last of 32 addresses
ANDLW 0x1F ;
BTFSC STATUS,Z ; Exit if last of 32 words,
GOTO START_WRITE ;
MOVLW 55h ; Start of required write sequence:
MOVWF PMCON2 ; Write 55h
MOVLW 0AAh ;
MOVWF PMCON2 ; Write AAh
BSF PMCON1,WR ; Set WR bit to begin write
NOP ; NOP instructions are forced as processor
; loads program memory write latches
NOP ;
INCF PMADRL,F ; Still loading latches Increment address
GOTO LOOP ; Write next latches
START_WRITE
BCF PMCON1,LWLO ; No more loading latches - Actually start Flash program
; memory write
MOVLW 55h ; Start of required write sequence:
MOVWF PMCON2 ; Write 55h
MOVLW 0AAh ;
MOVWF PMCON2 ; Write AAh
BSF PMCON1,WR ; Set WR bit to begin write
NOP ; NOP instructions are forced as processor writes
; all the program memory write latches simultaneously
NOP ; to program memory.
; After NOPs, the processor
; stalls until the self-write process in complete
; after write processor continues with 3rd instruction
BCF PMCON1,WREN ; Disable writes
BSF INTCON,GIE ; Enable interrupts
Required
Sequence
Required
Sequence
2011 Microchip Technology Inc. Preliminary DS41609A-page 105
PIC16(L)F1508/9
10.3 Modifying Flash Program Memory
When modifying existing data in a program memory
row, and data within that row must be preserved, it must
first be read and saved in a RAM image. Program
memory is modified using the following steps:
1. Load the starting address of the row to be
modified.
2. Read the existing data from the row into a RAM
image.
3. Modify the RAM image to contain the new data
to be written into program memory.
4. Load the starting address of the row to be
rewritten.
5. Erase the program memory row.
6. Load the write latches with data from the RAM
image.
7. Initiate a programming operation.
FIGURE 10-7: FLASH PROGRAM
MEMORY MODIFY
FLOWCHART
Start
Modify Operation
Read Operation
(Figure x.x)
Erase Operation
(Figure x.x)
Modify Image
The words to be modified are
changed in the RAM image
End
Modify Operation
WRITE Operation
use RAM image
(Figure x.x)
An image of the entire row read
must be stored in RAM
Figure 10-2
Figure 10-4
Figure 10-5
PIC16(L)F1508/9
DS41609A-page 106 Preliminary 2011 Microchip Technology Inc.
10.4 User ID, Device ID and
Configuration Word Access
Instead of accessing program memory, the User ID’s,
Device ID/Revision ID and Configuration Words can be
accessed when CFGS = 1 in the PMCON1 register.
This is the region that would be pointed to by
PC<15> = 1, but not all addresses are accessible.
Different access may exist for reads and writes. Refer
to Tab le 10- 2.
When read access is initiated on an address outside
the parameters listed in Table 10- 2, the
PMDATH:PMDATL register pair is cleared, reading
back ‘0’s.
TABLE 10-2: USER ID, DEVICE ID AND CONFIGURATION WORD ACCESS (CFGS = 1)
EXAMPLE 10-4: CONFIGURATION WORD AND DEVICE ID ACCESS
Address Function Read Access Write Access
8000h-8003h User IDs Yes Yes
8006h Device ID/Revision ID Yes No
8007h-8008h Configuration Words 1 and 2 Yes No
* This code block will read 1 word of program memory at the memory address:
* PROG_ADDR_LO (must be 00h-08h) data will be returned in the variables;
* PROG_DATA_HI, PROG_DATA_LO
BANKSEL PMADRL ; Select correct Bank
MOVLW PROG_ADDR_LO ;
MOVWF PMADRL ; Store LSB of address
CLRF PMADRH ; Clear MSB of address
BSF PMCON1,CFGS ; Select Configuration Space
BCF INTCON,GIE ; Disable interrupts
BSF PMCON1,RD ; Initiate read
NOP ; Executed (See Figure 10-2)
NOP ; Ignored (See Figure 10-2)
BSF INTCON,GIE ; Restore interrupts
MOVF PMDATL,W ; Get LSB of word
MOVWF PROG_DATA_LO ; Store in user location
MOVF PMDATH,W ; Get MSB of word
MOVWF PROG_DATA_HI ; Store in user location
2011 Microchip Technology Inc. Preliminary DS41609A-page 107
PIC16(L)F1508/9
10.5 Write Verify
It is considered good programming practice to verify that
program memory writes agree with the intended value.
Since program memory is stored as a full page then the
stored program memory contents are compared with the
intended data stored in RAM after the last write is
complete.
FIGURE 10-8: FLASH PROGRAM
MEMORY VERIFY
FLOWCHART
Start
Verify Operation
Read Operation
(Figure x.x)
End
Verify Operation
This routine assumes that the last row
of data written was from an image
saved in RAM. This image will be used
to verify the data currently stored in
Flash Program Memory.
PMDAT =
RAM image
?
Last
Word ?
Fail
Verify Operation
No
Yes
Yes
No
Figure 10-2
PIC16(L)F1508/9
DS41609A-page 108 Preliminary 2011 Microchip Technology Inc.
10.6 Flash Program Memory Control Registers
REGISTER 10-1: PMDATL: PROGRAM MEMORY DATA LOW BYTE REGISTER
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
PMDAT<7:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 PMDAT<7:0>: Read/write value for Least Significant bits of program memory
REGISTER 10-2: PMDATH: PROGRAM MEMORY DATA HIGH BYTE REGISTER
U-0 U-0 R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
—— PMDAT<13:8>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 Unimplemented: Read as ‘0’
bit 5-0 PMDAT<13:8>: Read/write value for Most Significant bits of program memory
REGISTER 10-3: PMADRL: PROGRAM MEMORY ADDRESS LOW BYTE REGISTER
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
PMADR<7:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 PMADR<7:0>: Specifies the Least Significant bits for program memory address
REGISTER 10-4: PMADRH: PROGRAM MEMORY ADDRESS HIGH BYTE REGISTER
U-1 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
— PMADR<14:8>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 Unimplemented: Read as ‘1’
bit 6-0 PMADR<14:8>: Specifies the Most Significant bits for program memory address
2011 Microchip Technology Inc. Preliminary DS41609A-page 109
PIC16(L)F1508/9
REGISTER 10-5: PMCON1: PROGRAM MEMORY CONTROL 1 REGISTER
U-1(1) R/W-0/0 R/W-0/0 R/W/HC-0/0 R/W/HC-x/q(2) R/W-0/0 R/S/HC-0/0 R/S/HC-0/0
— CFGS LWLO FREE WRERR WREN WR RD
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
S = Bit can only be set x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared HC = Bit is cleared by hardware
bit 7 Unimplemented: Read as ‘1’
bit 6 CFGS: Configuration Select bit
1 = Access Configuration, User ID and Device ID Registers
0 = Access Flash program memory
bit 5 LWLO: Load Write Latches Only bit(3)
1 = Only the addressed program memory write latch is loaded/updated on the next WR command
0 = The addressed program memory write latch is loaded/updated and a write of all program memory write latches
will be initiated on the next WR command
bit 4 FREE: Program Flash Erase Enable bit
1 = Performs an erase operation on the next WR command (hardware cleared upon completion)
0 = Performs a write operation on the next WR command
bit 3 WRERR: Program/Erase Error Flag bit
1 = Condition indicates an improper program or erase sequence attempt or termination (bit is set automatically
on any set attempt (write ‘1’) of the WR bit).
0 = The program or erase operation completed normally.
bit 2 WREN: Program/Erase Enable bit
1 = Allows program/erase cycles
0 = Inhibits programming/erasing of program Flash
bit 1 WR: Write Control bit
1 = Initiates a program Flash program/erase operation.
The operation is self-timed and the bit is cleared by hardware once operation is complete.
The WR bit can only be set (not cleared) in software.
0 = Program/erase operation to the Flash is complete and inactive.
bit 0 RD: Read Control bit
1 = Initiates a program Flash read. Read takes one cycle. RD is cleared in hardware. The RD bit can only be set
(not cleared) in software.
0 = Does not initiate a program Flash read.
Note 1: Unimplemented bit, read as ‘1’.
2: The WRERR bit is automatically set by hardware when a program memory write or erase operation is started (WR = 1).
3: The LWLO bit is ignored during a program memory erase operation (FREE = 1).
PIC16(L)F1508/9
DS41609A-page 110 Preliminary 2011 Microchip Technology Inc.
TABLE 10-3: SUMMARY OF REGISTERS ASSOCIATED WITH FLASH PROGRAM MEMORY
TABLE 10-4: SUMMARY OF CONFIGURATION WORD WITH FLASH PROGRAM MEMORY
REGISTER 10-6: PMCON2: PROGRAM MEMORY CONTROL 2 REGISTER
W-0/0 W-0/0 W-0/0 W-0/0 W-0/0 W-0/0 W-0/0 W-0/0
Program Memory Control Register 2
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
S = Bit can only be set x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 Flash Memory Unlock Pattern bits
To unlock writes, a 55h must be written first, followed by an AAh, before setting the WR bit of the
PMCON1 register. The value written to this register is used to unlock the writes. There are specific
timing requirements on these writes.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register on
Page
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PMCON1 —CFGS LWLO FREE WRERR WREN WR RD 109
PMCON2 Program Memory Control Register 2 110
PMADRL PMADRL<7:0> 108
PMADRH — PMADRH<6:0> 108
PMDATL PMDATL<7:0> 108
PMDATH —— PMDATH<5:0> 108
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by Flash program memory module.
Name Bits Bit -/7 Bit -/6 Bit 13/5 Bit 12/4 Bit 11/3 Bit 10/2 Bit 9/1 Bit 8/0 Register
on Page
CONFIG1 13:8 — — FCMEN IESO CLKOUTEN BOREN<1:0> —44
7:0 CP MCLRE PWRTE WDTE<1:0> FOSC<2:0>
CONFIG2 13:8 — — LVP DEBUG LPBOR BORV STVREN —45
7:0 — — — — — —WRT<1:0>
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by Flash program memory.
2011 Microchip Technology Inc. Preliminary DS41609A-page 111
PIC16(L)F1508/9
11.0 I/O PORTS
Each port has three standard registers for its operation.
These registers are:
• TRISx registers (data direction)
• PORTx registers (reads the levels on the pins of
the device)
• LATx registers (output latch)
Some ports may have one or more of the following
additional registers. These registers are:
• ANSELx (analog select)
• WPUx (weak pull-up)
In general, when a peripheral is enabled on a port pin,
that pin cannot be used as a general purpose output.
However, the pin can still be read.
The Data Latch (LATx registers) is useful for
read-modify-write operations on the value that the I/O
pins are driving.
A write operation to the LATx register has the same
effect as a write to the corresponding PORTx register.
A read of the LATx register reads of the values held in
the I/O PORT latches, while a read of the PORTx
register reads the actual I/O pin value.
Ports that support analog inputs have an associated
ANSELx register. When an ANSEL bit is set, the digital
input buffer associated with that bit is disabled.
Disabling the input buffer prevents analog signal levels
on the pin between a logic high and low from causing
excessive current in the logic input circuitry. A
simplified model of a generic I/O port, without the
interfaces to other peripherals, is shown in Figure 11-1.
FIGURE 11-1: GENERIC I/O PORT
OPERATION
TABLE 11-1: PORT AVAILABILITY PER
DEVICE
Device
PORTA
PORTB
PORTC
PIC16(L)F1508/9 ●●●
QD
CK
Write LATx
Data Register
I/O pin
Read PORTx
Write PORTx
TRISx
Read LATx
Data Bus
To peripherals
ANSELx
VDD
VSS
PIC16(L)F1508/9
DS41609A-page 112 Preliminary 2011 Microchip Technology Inc.
11.1 Alternate Pin Function
The Alternate Pin Function Control register is used to
steer specific peripheral input and output functions
between different pins. The APFCON register is shown
in Register 11-1. For this device family, the following
functions can be moved between different pins.
•SS
•T1G
•CLC1
• NCO1
These bits have no effect on the values of any TRIS
register. PORT and TRIS overrides will be routed to the
correct pin. The unselected pin will be unaffected.
REGISTER 11-1: APFCON: ALTERNATE PIN FUNCTION CONTROL REGISTER
U-0 U-0 U-0 R/W-0/0 R/W-0/0 U-0 R/W-0/0 R/W-0/0
— — — SSSEL T1GSEL —CLC1SEL NCO1SEL
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-5 Unimplemented: Read as ‘0’
bit 4 SSSEL: Pin Selection bit
1 =SS
function is on RA3
0 =SS
function is on RC6
bit 3 T1GSEL: Pin Selection bit
1 = T1G function is on RA3
0 = T1G function is on RA4
bit 2 Unimplemented: Read as ‘0’
bit 1 CLC1SEL: Pin Selection bit
1 = CLC1 function is on RC5
0 = CLC1 function is on RA2
bit 0 NCO1SEL: Pin Selection bit
1 = NCO1 function is on RA6
0 = NCO1 function is on RC1
2011 Microchip Technology Inc. Preliminary DS41609A-page 113
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11.2 PORTA Registers
PORTA is a 6-bit wide, bidirectional port. The
corresponding data direction register is TRISA
(Register 11-3). Setting a TRISA bit (= 1) will make the
corresponding PORTA pin an input (i.e., disable the
output driver). Clearing a TRISA bit (= 0) will make the
corresponding PORTA pin an output (i.e., enables
output driver and puts the contents of the output latch
on the selected pin). The exception is RA3, which is
input only and its TRIS bit will always read as ‘1’.
Example 11-1 shows how to initialize an I/O port.
Reading the PORTA register (Register 11-2) reads the
status of the pins, whereas writing to it will write to the
PORT latch. All write operations are read-modify-write
operations. Therefore, a write to a port implies that the
port pins are read, this value is modified and then
written to the PORT data latch (LATA).
The TRISA register (Register 11-3) controls the
PORTA pin output drivers, even when they are being
used as analog inputs. The user should ensure the bits
in the TRISA register are maintained set when using
them as analog inputs. I/O pins configured as analog
input always read ‘0’.
11.2.1 ANSELA REGISTER
The ANSELA register (Register 11-5) is used to
configure the Input mode of an I/O pin to analog.
Setting the appropriate ANSELA bit high will cause all
digital reads on the pin to be read as ‘0’ and allow
analog functions on the pin to operate correctly.
The state of the ANSELA bits has no effect on digital
output functions. A pin with TRIS clear and ANSEL set
will still operate as a digital output, but the Input mode
will be analog. This can cause unexpected behavior
when executing read-modify-write instructions on the
affected port.
EXAMPLE 11-1: INITIALIZING PORTA
11.2.2 PORTA FUNCTIONS AND OUTPUT
PRIORITIES
Each PORTA pin is multiplexed with other functions. The
pins, their combined functions and their output priorities
are shown in Table 11-2.
When multiple outputs are enabled, the actual pin
control goes to the peripheral with the highest priority.
Analog input functions, such as ADC and comparator
inputs, are not shown in the priority lists. These inputs
are active when the I/O pin is set for Analog mode using
the ANSELx registers. Digital output functions may
control the pin when it is in Analog mode with the
priority shown below in Table 11-2.
Note: The ANSELA bits default to the Analog
mode after Reset. To use any pins as
digital general purpose or peripheral
inputs, the corresponding ANSEL bits
must be initialized to ‘0’ by user software.
BANKSEL PORTA ;
CLRF PORTA ;Init PORTA
BANKSEL LATA ;Data Latch
CLRF LATA ;
BANKSEL ANSELA ;
CLRF ANSELA ;digital I/O
BANKSEL TRISA ;
MOVLW B'00111000' ;Set RA<5:3> as inputs
MOVWF TRISA ;and set RA<2:0> as
;outputs
TABLE 11-2: PORTA OUTPUT PRIORITY
Pin Name Function Priority(1)
RA0 ICSPDAT
DACOUT1
RA0
RA1 RA1
RA2 DACOUT2
CLC1(2)
C1OUT
PWM3
RA2
RA3 None
RA4 CLKOUT
SOSCO
RA4
RA5 SOSCI
RA5
Note 1: Priority listed from highest to lowest.
2: Default pin (see APFCON register).
3: Alternate pin (see APFCON register).
PIC16(L)F1508/9
DS41609A-page 114 Preliminary 2011 Microchip Technology Inc.
REGISTER 11-2: PORTA: PORTA REGISTER
U-0 U-0 R/W-x/x R/W-x/x R-x/x R/W-x/x R/W-x/x R/W-x/x
—— RA5 RA4 RA3 RA2 RA1 RA0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 Unimplemented: Read as ‘0’
bit 5-0 RA<5:0>: PORTA I/O Value bits(1)
1 = Port pin is > VIH
0 = Port pin is < VIL
Note 1: Writes to PORTA are actually written to corresponding LATA register. Reads from PORTA register is return
of actual I/O pin values.
REGISTER 11-3: TRISA: PORTA TRI-STATE REGISTER
U-0 U-0 R/W-1/1 R/W-1/1 U-1 R/W-1/1 R/W-1/1 R/W-1/1
—— TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 Unimplemented: Read as ‘0’
bit 5-4 TRISA<5:4>: PORTA Tri-State Control bit
1 = PORTA pin configured as an input (tri-stated)
0 = PORTA pin configured as an output
bit 3 Unimplemented: Read as ‘1’
bit 2-0 TRISA<2:0>: PORTA Tri-State Control bit
1 = PORTA pin configured as an input (tri-stated)
0 = PORTA pin configured as an output
Note 1: Unimplemented, read as ‘1’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 115
PIC16(L)F1508/9
REGISTER 11-4: LATA: PORTA DATA LATCH REGISTER
U-0 U-0 R/W-x/u R/W-x/u U-0 R/W-x/u R/W-x/u R/W-x/u
——LATA5LATA4— LATA2 LATA1 LATA0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 Unimplemented: Read as ‘0’
bit 5-4 LATA<5:4>: RA<5:4> Output Latch Value bits(1)
bit 3 Unimplemented: Read as ‘0’
bit 2-0 LATA<2:0>: RA<2:0> Output Latch Value bits(1)
Note 1: Writes to PORTA are actually written to corresponding LATA register. Reads from PORTA register is return
of actual I/O pin values.
REGISTER 11-5: ANSELA: PORTA ANALOG SELECT REGISTER
U-0 U-0 U-0 R/W-1/1 U-0 R/W-1/1 R/W-1/1 R/W-1/1
— — — ANSA4 — ANSA2 ANSA1 ANSA0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-5 Unimplemented: Read as ‘0’
bit 4 ANSA4: Analog Select between Analog or Digital Function on pins RA4, respectively
1 = Analog input. Pin is assigned as analog input(1). Digital input buffer disabled.
0 = Digital I/O. Pin is assigned to port or digital special function.
bit 3 Unimplemented: Read as ‘0’
bit 2-0 ANSA<2:0>: Analog Select between Analog or Digital Function on pins RA<2:0>, respectively
1 = Analog input. Pin is assigned as analog input(1). Digital input buffer disabled.
0 = Digital I/O. Pin is assigned to port or digital special function.
Note 1: When setting a pin to an analog input, the corresponding TRIS bit must be set to Input mode in order to
allow external control of the voltage on the pin.
PIC16(L)F1508/9
DS41609A-page 116 Preliminary 2011 Microchip Technology Inc.
TABLE 11-3: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
TABLE 11-4: SUMMARY OF CONFIGURATION WORD WITH PORTA
REGISTER 11-6: WPUA: WEAK PULL-UP PORTA REGISTER
U-0 U-0 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1
—— WPUA5 WPUA4 WPUA3 WPUA2 WPUA1 WPUA0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 Unimplemented: Read as ‘0’
bit 5-0 WPUA<5:0>: Weak Pull-up Register bits(3)
1 = Pull-up enabled
0 = Pull-up disabled
Note 1: Global WPUEN bit of the OPTION_REG register must be cleared for individual pull-ups to be enabled.
2: The weak pull-up device is automatically disabled if the pin is configured as an output.
3: For the WPUA3 bit, when MCLRE = 1, weak pull-up is internally enabled, but not reported here.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
ANSELA — — —ANSA4— ANSA2 ANSA1 ANSA0 115
APFCON — — — SSSEL T1GSEL — CLC1SEL NCO1SEL 112
LATA ——LATA5LATA4—LATA2LATA1LATA0115
OPTION_REG WPUEN INTEDG TMR0CS TMR0SE PSA PS<2:0> 165
PORTA —— RA5 RA4 RA3 RA2 RA1 RA0 114
TRISA —— TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
WPUA —— WPUA5 WPUA4 WPUA3 WPUA2 WPUA1 WPUA0 116
Legend: x = unknown, u = unchanged, – = unimplemented locations read as ‘0’. Shaded cells are not used by PORTA.
Note 1: Unimplemented, read as ‘1’.
Name Bits Bit -/7 Bit -/6 Bit 13/5 Bit 12/4 Bit 11/3 Bit 10/2 Bit 9/1 Bit 8/0 Register
on Page
CONFIG1 13:8 — — FCMEN IESO CLKOUTEN BOREN<1:0> —44
7:0 CP MCLRE PWRTE WDTE<1:0> FOSC<2:0>
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by PORTA.
2011 Microchip Technology Inc. Preliminary DS41609A-page 117
PIC16(L)F1508/9
11.3 PORTB Registers
PORTB is a 4-bit wide, bidirectional port. The
corresponding data direction register is TRISB
(Register 11-3). Setting a TRISB bit (= 1) will make the
corresponding PORTB pin an input (i.e., disable the
output driver). Clearing a TRISB bit (= 0) will make the
corresponding PORTB pin an output (i.e., enables
output driver and puts the contents of the output latch
on the selected pin). Example 11-1 shows how to
initialize an I/O port.
Reading the PORTB register (Register 11-2) reads the
status of the pins, whereas writing to it will write to the
PORT latch. All write operations are read-modify-write
operations. Therefore, a write to a port implies that the
port pins are read, this value is modified and then
written to the PORT data latch (LATB).
The TRISB register (Register 11-3) controls the
PORTB pin output drivers, even when they are being
used as analog inputs. The user should ensure the bits
in the TRISB register are maintained set when using
them as analog inputs. I/O pins configured as analog
input always read ‘0’.
11.3.1 ANSELB REGISTER
The ANSELB register (Register 11-5) is used to
configure the Input mode of an I/O pin to analog.
Setting the appropriate ANSELB bit high will cause all
digital reads on the pin to be read as ‘0’ and allow
analog functions on the pin to operate correctly.
The state of the ANSELB bits has no effect on digital
output functions. A pin with TRIS clear and ANSEL set
will still operate as a digital output, but the Input mode
will be analog. This can cause unexpected behavior
when executing read-modify-write instructions on the
affected port.
11.3.2 PORTB FUNCTIONS AND OUTPUT
PRIORITIES
Each PORTB pin is multiplexed with other functions. The
pins, their combined functions and their output priorities
are shown in Table 11-2.
When multiple outputs are enabled, the actual pin
control goes to the peripheral with the highest priority.
Analog input functions, such as ADC and comparator
inputs, are not shown in the priority lists. These inputs
are active when the I/O pin is set for Analog mode using
the ANSELx registers. Digital output functions may
control the pin when it is in Analog mode with the
priority shown below in Table 11-2.
Note: The ANSELB bits default to the Analog
mode after Reset. To use any pins as
digital general purpose or peripheral
inputs, the corresponding ANSEL bits
must be initialized to ‘0’ by user software.
TABLE 11-5: PORTB OUTPUT PRIORITY
Pin Name Function Priority(1)
RB4 SDA
RB4
RB5 RB5
RB6 SCL
SCK
RB6
RB7 CLC3
TX
RB7
Note 1: Priority listed from highest to lowest.
2: Default pin (see APFCON register).
3: Alternate pin (see APFCON register).
PIC16(L)F1508/9
DS41609A-page 118 Preliminary 2011 Microchip Technology Inc.
REGISTER 11-7: PORTB: PORTB REGISTER
R/W-x/x R/W-x/x R/W-x/x R/W-x/x U-0 U-0 U-0 U-0
RB7 RB6 RB5 RB4 — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 RB<7:4>: PORTB I/O Value bits(1)
1 = Port pin is > VIH
0 = Port pin is < VIL
bit 3-0 Unimplemented: Read as ‘0’
Note 1: Writes to PORTB are actually written to corresponding LATB register. Reads from PORTB register is
return of actual I/O pin values.
REGISTER 11-8: TRISB: PORTB TRI-STATE REGISTER
R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 U-0 U-0 U-0 U-0
TRISB7 TRISB6 TRISB5 TRISB4 — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 RB<7:4>: PORTB Tri-State Control bits
1 = PORTB pin configured as an input (tri-stated)
0 = PORTB pin configured as an output
bit 3-0 Unimplemented: Read as ‘0’
2011 Microchip Technology Inc. Preliminary DS41609A-page 119
PIC16(L)F1508/9
REGISTER 11-9: LATB: PORTB DATA LATCH REGISTER
R/W-x/u R/W-x/u R/W-x/u R/W-x/u U-0 U-0 U-0 U-0
LATB7 LATB6 LATB5 LATB4 — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 LATB<7:4>: RB<7:4> Output Latch Value bits(1)
bit 3-0 Unimplemented: Read as ‘0’
Note 1: Writes to PORTB are actually written to corresponding LATB register. Reads from PORTB register is
return of actual I/O pin values.
REGISTER 11-10: ANSELB: PORTB ANALOG SELECT REGISTER
U-0 U-0 R/W-1/1 R/W-1/1 U-0 U-0 U-0 U-0
—— ANSB5 ANSB4 — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 Unimplemented: Read as ‘0’
bit 5-4 ANSB<5:4>: Analog Select between Analog or Digital Function on pins RB<5:4>, respectively
1 = Analog input. Pin is assigned as analog input(1). Digital input buffer disabled.
0 = Digital I/O. Pin is assigned to port or digital special function.
bit 3-0 Unimplemented: Read as ‘0’
Note 1: When setting a pin to an analog input, the corresponding TRIS bit must be set to Input mode in order to
allow external control of the voltage on the pin.
PIC16(L)F1508/9
DS41609A-page 120 Preliminary 2011 Microchip Technology Inc.
TABLE 11-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
TABLE 11-7: SUMMARY OF CONFIGURATION WORD WITH PORTB
REGISTER 11-11: WPUB: WEAK PULL-UP PORTB REGISTER
R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 U-0 U-0 U-0 U-0
WPUB7 WPUB6 WPUB5 WPUB4 — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 WPUB<7:4>: Weak Pull-up Register bits
1 = Pull-up enabled
0 = Pull-up disabled
bit 3-0 Unimplemented: Read as ‘0’
Note 1: Global WPUEN bit of the OPTION_REG register must be cleared for individual pull-ups to be enabled.
2: The weak pull-up device is automatically disabled if the pin is configured as an output.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
ANSELB —— ANSB5 ANSB4 — — — — 119
APFCON — — — SSSEL T1GSEL — CLC1SEL NCO1SEL 112
LATB LATB7 LATB6 LATB5 LATB4 — — — — 119
OPTION_REG WPUEN INTEDG TMR0CS TMR0SE PSA PS<2:0> 165
PORTB RB7 RB6 RB5 RB4 — — — — 118
TRISB TRISB7 TRISB6 TRISB5 TRISB4 — — — — 118
WPUB WPUB7 WPUB6 WPUB5 WPUB4 — — — — 120
Legend: x = unknown, u = unchanged, – = unimplemented locations read as ‘0’. Shaded cells are not used by PORTB.
Note 1: Unimplemented, read as ‘1’.
Name Bits Bit -/7 Bit -/6 Bit 13/5 Bit 12/4 Bit 11/3 Bit 10/2 Bit 9/1 Bit 8/0 Register
on Page
CONFIG1 13:8 — — FCMEN IESO CLKOUTEN BOREN<1:0> —44
7:0 CP MCLRE PWRTE WDTE<1:0> FOSC<2:0>
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by PORTB.
2011 Microchip Technology Inc. Preliminary DS41609A-page 121
PIC16(L)F1508/9
11.4 PORTC Registers
PORTC is a 8-bit wide, bidirectional port. The
corresponding data direction register is TRISC
(Register 11-13). Setting a TRISC bit (= 1) will make
the corresponding PORTC pin an input (i.e., put the
corresponding output driver in a High-Impedance
mode). Clearing a TRISC bit (= 0) will make the
corresponding PORTC pin an output (i.e., enable the
output driver and put the contents of the output latch
on the selected pin). Example 11-1 shows how to
initialize an I/O port.
Reading the PORTC register (Register 11-12) reads the
status of the pins, whereas writing to it will write to the
PORT latch. All write operations are read-modify-write
operations. Therefore, a write to a port implies that the
port pins are read, this value is modified and then written
to the PORT data latch (LATC).
The TRISC register (Register 11-13) controls the
PORTC pin output drivers, even when they are being
used as analog inputs. The user should ensure the bits in
the TRISC register are maintained set when using them
as analog inputs. I/O pins configured as analog input
always read ‘0’.
11.4.1 ANSELC REGISTER
The ANSELC register (Register 11-15) is used to
configure the Input mode of an I/O pin to analog.
Setting the appropriate ANSELC bit high will cause all
digital reads on the pin to be read as ‘0’ and allow
analog functions on the pin to operate correctly.
The state of the ANSELC bits has no effect on digital out-
put functions. A pin with TRIS clear and ANSELC set will
still operate as a digital output, but the Input mode will be
analog. This can cause unexpected behavior when exe-
cuting read-modify-write instructions on the affected
port.
11.4.2 PORTC FUNCTIONS AND OUTPUT
PRIORITIES
Each PORTC pin is multiplexed with other functions. The
pins, their combined functions and their output priorities
are shown in Table 11-8.
When multiple outputs are enabled, the actual pin
control goes to the peripheral with the highest priority.
Analog input and some digital input functions are not
included in the output priority list. These input functions
can remain active when the pin is configured as an
output. Certain digital input functions override other
port functions and are included in the output priority list.
Note: The ANSELC bits default to the Analog
mode after Reset. To use any pins as
digital general purpose or peripheral
inputs, the corresponding ANSEL bits
must be initialized to ‘0’ by user software.
TABLE 11-8: PORTC OUTPUT PRIORITY
Pin Name Function Priority(1)
RC0 CLC2
RC0
RC1 NCO1(2)
PWM4
RC1
RC2 RC2
RC3 PWM2
RC3
RC4 CWG1B
CLC4
C2OUT
RC4
RC5 CWG1A
CLC1(3)
PWM1
RC5
RC6 NCO1(3)
RC6
RC7 SDO
RC7
Note 1: Priority listed from highest to lowest.
2: Default pin (see APFCON register).
3: Alternate pin (see APFCON register).
PIC16(L)F1508/9
DS41609A-page 122 Preliminary 2011 Microchip Technology Inc.
REGISTER 11-12: PORTC: PORTC REGISTER
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 RC<7:0>: PORTC General Purpose I/O Pin bits
1 = Port pin is > VIH
0 = Port pin is < VIL
REGISTER 11-13: TRISC: PORTC TRI-STATE REGISTER
R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1
TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 TRISC<7:0>: PORTC Tri-State Control bits
1 = PORTC pin configured as an input (tri-stated)
0 = PORTC pin configured as an output
REGISTER 11-14: LATC: PORTC DATA LATCH REGISTER
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
LATC7 LATC6 LATC5 LATC4 LATC3 LATC2 LATC1 LATC0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 LATC<7:0>: PORTC Output Latch Value bits(1)
Note 1: Writes to PORTC are actually written to corresponding LATC register. Reads from PORTC register is
return of actual I/O pin values.
2011 Microchip Technology Inc. Preliminary DS41609A-page 123
PIC16(L)F1508/9
TABLE 11-9: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
REGISTER 11-15: ANSELC: PORTC ANALOG SELECT REGISTER
R/W-1/1 R/W-1/1 U-0 U-0 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1
ANSC7 ANSC6 —— ANSC3 ANSC2 ANSC1 ANSC0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 ANSC<7:6>: Analog Select between Analog or Digital Function on pins RC<7:6>, respectively
1 = Analog input. Pin is assigned as analog input(1). Digital input buffer disabled.
0 = Digital I/O. Pin is assigned to port or digital special function.
bit 5-4 Unimplemented: Read as ‘0’
bit 3-0 ANSC<3:0>: Analog Select between Analog or Digital Function on pins RC<3:0>, respectively
1 = Analog input. Pin is assigned as analog input(1). Digital input buffer disabled.
0 = Digital I/O. Pin is assigned to port or digital special function.
Note 1: When setting a pin to an analog input, the corresponding TRIS bit must be set to Input mode in order to
allow external control of the voltage on the pin.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
ANSELC ANSC7 ANSC6 —— ANSC3 ANSC2 ANSC1 ANSC0 123
LATC LATC7 LATC6 LATC5 LATC4 LATC3 LATC2 LATC1 LATC0 122
PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 122
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
Legend: x = unknown, u = unchanged, - = unimplemented locations read as ‘0’. Shaded cells are not used by PORTC.
PIC16(L)F1508/9
DS41609A-page 124 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 125
PIC16(L)F1508/9
12.0 INTERRUPT-ON-CHANGE
The PORTA and PORTB pins can be configured to
operate as Interrupt-On-Change (IOC) pins. An interrupt
can be generated by detecting a signal that has either a
rising edge or a falling edge. Any individual port pin, or
combination of port pins, can be configured to generate
an interrupt. The interrupt-on-change module has the
following features:
• Interrupt-on-Change enable (Master Switch)
• Individual pin configuration
• Rising and falling edge detection
• Individual pin interrupt flags
Figure 12-1 is a block diagram of the IOC module.
12.1 Enabling the Module
To allow individual port pins to generate an interrupt, the
IOCIE bit of the INTCON register must be set. If the
IOCIE bit is disabled, the edge detection on the pin will
still occur, but an interrupt will not be generated.
12.2 Individual Pin Configuration
For each port pin, a rising edge detector and a falling
edge detector are present. To enable a pin to detect a
rising edge, the associated bit of the IOCxP register is
set. To enable a pin to detect a falling edge, the
associated bit of the IOCxN register is set.
A pin can be configured to detect rising and falling
edges simultaneously by setting both associated bits of
the IOCxP and IOCxN registers, respectively.
12.3 Interrupt Flags
The IOCAFx and IOCBFx bits located in the IOCAF and
IOCBF registers, respectively, are status flags that
correspond to the interrupt-on-change pins of the
associated port. If an expected edge is detected on an
appropriately enabled pin, then the status flag for that pin
will be set, and an interrupt will be generated if the IOCIE
bit is set. The IOCIF bit of the INTCON register reflects
the status of all IOCAFx and IOCBFx bits.
12.4 Clearing Interrupt Flags
The individual status flags, (IOCAFx and IOCBFx bits),
can be cleared by resetting them to zero. If another edge
is detected during this clearing operation, the associated
status flag will be set at the end of the sequence,
regardless of the value actually being written.
In order to ensure that no detected edge is lost while
clearing flags, only AND operations masking out known
changed bits should be performed. The following
sequence is an example of what should be performed.
EXAMPLE 12-1: CLEARING INTERRUPT
FLAGS
(PORTA EXAMPLE)
12.5 Operation in Sleep
The interrupt-on-change interrupt sequence will wake
the device from Sleep mode, if the IOCIE bit is set.
If an edge is detected while in Sleep mode, the IOCxF
register will be updated prior to the first instruction
executed out of Sleep.
MOVLW 0xff
XORWF IOCAF, W
ANDWF IOCAF, F
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DS41609A-page 126 Preliminary 2011 Microchip Technology Inc.
FIGURE 12-1: INTERRUPT-ON-CHANGE BLOCK DIAGRAM (PORTA EXAMPLE)
D
CK
R
Q
D
CK
R
Q
RAx
IOCANx
IOCAPx
Q2
D
CK
SQ
Q4Q1
Data Bus =
0 or 1
Write IOCAFx
IOCIE
To Data Bus
IOCAFx
Edge
Detect
IOC interrupt
to CPU core
From all other
IOCAFx individual
Pin Detectors
Q1
Q2
Q3
Q4
Q4Q1
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q4
Q4Q1 Q4Q1 Q4Q1
2011 Microchip Technology Inc. Preliminary DS41609A-page 127
PIC16(L)F1508/9
12.6 Interrupt-On-Change Registers
REGISTER 12-1: IOCAP: INTERRUPT-ON-CHANGE PORTA POSITIVE EDGE REGISTER
U-0 U-0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
—— IOCAP5 IOCAP4 IOCAP3 IOCAP2 IOCAP1 IOCAP0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 Unimplemented: Read as ‘0’
bit 5-0 IOCAP<5:0>: Interrupt-on-Change PORTA Positive Edge Enable bits
1 = Interrupt-on-Change enabled on the pin for a positive going edge. IOCAFx bit and IOCIF flag will be set
upon detecting an edge.
0 = Interrupt-on-Change disabled for the associated pin.
REGISTER 12-2: IOCAN: INTERRUPT-ON-CHANGE PORTA NEGATIVE EDGE REGISTER
U-0 U-0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
—— IOCAN5 IOCAN4 IOCAN3 IOCAN2 IOCAN1 IOCAN0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 Unimplemented: Read as ‘0’
bit 5-0 IOCAN<5:0>: Interrupt-on-Change PORTA Negative Edge Enable bits
1 = Interrupt-on-Change enabled on the pin for a negative going edge. IOCAFx bit and IOCIF flag will be set
upon detecting an edge.
0 = Interrupt-on-Change disabled for the associated pin.
REGISTER 12-3: IOCAF: INTERRUPT-ON-CHANGE PORTA FLAG REGISTER
U-0 U-0 R/W/HS-0/0 R/W/HS-0/0 R/W/HS-0/0 R/W/HS-0/0 R/W/HS-0/0 R/W/HS-0/0
—— IOCAF5 IOCAF4 IOCAF3 IOCAF2 IOCAF1 IOCAF0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared HS - Bit is set in hardware
bit 7-6 Unimplemented: Read as ‘0’
bit 5-0 IOCAF<5:0>: Interrupt-on-Change PORTA Flag bits
1 = An enabled change was detected on the associated pin.
Set when IOCAPx = 1 and a rising edge was detected on RAx, or when IOCANx = 1 and a falling edge was
detected on RAx.
0 = No change was detected, or the user cleared the detected change.
PIC16(L)F1508/9
DS41609A-page 128 Preliminary 2011 Microchip Technology Inc.
REGISTER 12-4: IOCBP: INTERRUPT-ON-CHANGE PORTB POSITIVE EDGE REGISTER
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 U-0 U-0 U-0 U-0
IOCBP7 IOCBP6 IOCBP5 IOCBP4 — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 IOCBP<7:4>: Interrupt-on-Change PORTB Positive Edge Enable bits
1 = Interrupt-on-Change enabled on the pin for a positive going edge. IOCBFx bit and IOCIF flag will be set
upon detecting an edge.
0 = Interrupt-on-Change disabled for the associated pin.
bit 3-0 Unimplemented: Read as ‘0’
REGISTER 12-5: IOCBN: INTERRUPT-ON-CHANGE PORTB NEGATIVE EDGE REGISTER
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 U-0 U-0 U-0 U-0
IOCBN7 IOCBN6 IOCBN5 IOCBN4 — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 IOCBN<7:4>: Interrupt-on-Change PORTB Negative Edge Enable bits
1 = Interrupt-on-Change enabled on the pin for a negative going edge. IOCBFx bit and IOCIF flag will be set
upon detecting an edge.
0 = Interrupt-on-Change disabled for the associated pin.
bit 3-0 Unimplemented: Read as ‘0’
REGISTER 12-6: IOCBF: INTERRUPT-ON-CHANGE PORTB FLAG REGISTER
R/W/HS-0/0 R/W/HS-0/0 R/W/HS-0/0 R/W/HS-0/0 U-0 U-0 U-0 U-0
IOCBF7 IOCBF6 IOCBF5 IOCBF4 — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared HS - Bit is set in hardware
bit 7-4 IOCBF<7:4>: Interrupt-on-Change PORTB Flag bits
1 = An enabled change was detected on the associated pin.
Set when IOCBPx = 1 and a rising edge was detected on RBx, or when IOCBNx = 1 and a falling edge was
detected on RBx.
0 = No change was detected, or the user cleared the detected change.
bit 3-0 Unimplemented: Read as ‘0’
2011 Microchip Technology Inc. Preliminary DS41609A-page 129
PIC16(L)F1508/9
TABLE 12-1: SUMMARY OF REGISTERS ASSOCIATED WITH INTERRUPT-ON-CHANGE
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
ANSELA ———ANSA4— ANSA2 ANSA1 ANSA0 115
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
IOCAF —— IOCAF5 IOCAF4 IOCAF3 IOCAF2 IOCAF1 IOCAF0 127
IOCAN —— IOCAN5 IOCAN4 IOCAN3 IOCAN2 IOCAN1 IOCAN0 127
IOCAP —— IOCAP5 IOCAP4 IOCAP3 IOCAP2 IOCAP1 IOCAP0 127
IOCBF IOCBF7 IOCBF6 IOCBF5 IOCBF4 ————128
IOCBN IOCBN7 IOCBN6 IOCBN5 IOCBN4 ————128
IOCBP IOCBP7 IOCBP6 IOCBP5 IOCBP4 ————128
TRISA —— TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
TRISB TRISB7 TRISB6 TRISB5 TRISB4 ————118
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by interrupt-on-change.
Note 1: Unimplemented, read as ‘1’.
PIC16(L)F1508/9
DS41609A-page 130 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 131
PIC16(L)F1508/9
13.0 FIXED VOLTAGE REFERENCE
(FVR)
The Fixed Voltage Reference, or FVR, is a stable
voltage reference, independent of VDD, with 1.024V,
2.048V or 4.096V selectable output levels. The output
of the FVR can be configured to supply a reference
voltage to the following:
• ADC input channel
• Comparator positive input
• Comparator negative input
The FVR can be enabled by setting the FVREN bit of
the FVRCON register.
13.1 Independent Gain Amplifier
The output of the FVR supplied to the ADC and
Comparators is routed through a programmable gain
amplifier. Each amplifier can be programmed for a gain
of 1x, 2x or 4x, to produce the three possible voltage
levels.
The ADFVR<1:0> bits of the FVRCON register are
used to enable and configure the gain amplifier settings
for the reference supplied to the ADC module. Refer-
ence Section 15.0 “Analog-to-Digital Converter
(ADC) Module” for additional information.
The CDAFVR<1:0> bits of the FVRCON register are
used to enable and configure the gain amplifier settings
for the reference supplied to the comparator modules.
Reference Section 17.0 “Comparator Module” for
additional information.
13.2 FVR Stabilization Period
When the Fixed Voltage Reference module is enabled, it
requires time for the reference and amplifier circuits to
stabilize. Once the circuits stabilize and are ready for use,
the FVRRDY bit of the FVRCON register will be set. See
Section 29.0 “Electrical Specifications” for the
minimum delay requirement.
FIGURE 13-1: VOLTAGE REFERENCE BLOCK DIAGRAM
ADFVR<1:0>
CDAFVR<1:0>
X1
X2
X4
X1
X2
X4
2
2
FVR BUFFER1
(To ADC Module)
FVR BUFFER2
(To Comparators)
+
_
FVREN FVRRDY
Any peripheral requiring the
Fixed Reference
(See Table 13-1)
TABLE 13-1: PERIPHERALS REQUIRING THE FIXED VOLTAGE REFERENCE (FVR)
Peripheral Conditions Description
HFINTOSC FOSC<2:0> = 010 and
IRCF<3:0> = 000x
INTOSC is active and device is not in Sleep.
BOR
BOREN<1:0> = 11 BOR always enabled.
BOREN<1:0> = 10 and BORFS = 1BOR disabled in Sleep mode, BOR Fast Start enabled.
BOREN<1:0> = 01 and BORFS = 1BOR under software control, BOR Fast Start enabled.
LDO All PIC16F1508/9 devices, when
VREGPM = 1 and not in Sleep
The device runs off of the Low-Power Regulator when in
Sleep mode.
PIC16(L)F1508/9
DS41609A-page 132 Preliminary 2011 Microchip Technology Inc.
13.3 FVR Control Registers
TABLE 13-2: SUMMARY OF REGISTERS ASSOCIATED WITH THE FIXED VOLTAGE REFERENCE
REGISTER 13-1: FVRCON: FIXED VOLTAGE REFERENCE CONTROL REGISTER
R/W-0/0 R-q/q R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
FVREN FVRRDY(1) TSEN TSRNG CDAFVR<1:0> ADFVR<1:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared q = Value depends on condition
bit 7 FVREN: Fixed Voltage Reference Enable bit
1 = Fixed Voltage Reference is enabled
0 = Fixed Voltage Reference is disabled
bit 6 FVRRDY: Fixed Voltage Reference Ready Flag bit(1)
1 = Fixed Voltage Reference output is ready for use
0 = Fixed Voltage Reference output is not ready or not enabled
bit 5 TSEN: Temperature Indicator Enable bit(3)
1 = Temperature Indicator is enabled
0 = Temperature Indicator is disabled
bit 4 TSRNG: Temperature Indicator Range Selection bit(3)
1 =VOUT = VDD - 4VT (High Range)
0 =V
OUT = VDD - 2VT (Low Range)
bit 3-2 CDAFVR<1:0>: Comparator Fixed Voltage Reference Selection bits
11 = Comparator Fixed Voltage Reference Peripheral output is 4x (4.096V)(2)
10 = Comparator Fixed Voltage Reference Peripheral output is 2x (2.048V)(2)
01 = Comparator Fixed Voltage Reference Peripheral output is 1x (1.024V)
00 = Comparator Fixed Voltage Reference Peripheral output is off
bit 1-0 ADFVR<1:0>: ADC Fixed Voltage Reference Selection bit
11 = ADC Fixed Voltage Reference Peripheral output is 4x (4.096V)(2)
10 = ADC Fixed Voltage Reference Peripheral output is 2x (2.048V)(2)
01 = ADC Fixed Voltage Reference Peripheral output is 1x (1.024V)
00 = ADC Fixed Voltage Reference Peripheral output is off
Note 1: FVRRDY is always ‘1’ for the PIC16F1508/9 devices.
2: Fixed Voltage Reference output cannot exceed VDD.
3: See Section 14.0 “Temperature Indicator Module” for additional information.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on page
FVRCON FVREN FVRRDY TSEN TSRNG CDAFVR>1:0> ADFVR<1:0> 132
Legend: Shaded cells are unused by the Fixed Voltage Reference module.
2011 Microchip Technology Inc. Preliminary DS41609A-page 133
PIC16(L)F1508/9
14.0 TEMPERATURE INDICATOR
MODULE
This family of devices is equipped with a temperature
circuit designed to measure the operating temperature
of the silicon die. The circuit’s range of operating
temperature falls between -40°C and +85°C. The
output is a voltage that is proportional to the device
temperature. The output of the temperature indicator is
internally connected to the device ADC.
The circuit may be used as a temperature threshold
detector or a more accurate temperature indicator,
depending on the level of calibration performed. A one-
point calibration allows the circuit to indicate a
temperature closely surrounding that point. A two-point
calibration allows the circuit to sense the entire range
of temperature more accurately. Reference Application
Note AN1333, “Use and Calibration of the Internal
Temperature Indicator” (DS01333) for more details
regarding the calibration process.
14.1 Circuit Operation
Figure 14-1 shows a simplified block diagram of the
temperature circuit. The proportional voltage output is
achieved by measuring the forward voltage drop across
multiple silicon junctions.
Equation 14-1 describes the output characteristics of
the temperature indicator.
EQUATION 14-1: VOUT RANGES
The temperature sense circuit is integrated with the
Fixed Voltage Reference (FVR) module. See
Section 13.0 “Fixed Voltage Reference (FVR)” for
more information.
The circuit is enabled by setting the TSEN bit of the
FVRCON register. When disabled, the circuit draws no
current.
The circuit operates in either high or low range. The high
range, selected by setting the TSRNG bit of the
FVRCON register, provides a wider output voltage. This
provides more resolution over the temperature range,
but may be less consistent from part to part. This range
requires a higher bias voltage to operate and thus, a
higher VDD is needed.
The low range is selected by clearing the TSRNG bit of
the FVRCON register. The low range generates a lower
voltage drop and thus, a lower bias voltage is needed to
operate the circuit. The low range is provided for low
voltage operation.
FIGURE 14-1: TEMPERATURE CIRCUIT
DIAGRAM
14.2 Minimum Operating VDD
When the temperature circuit is operated in low range,
the device may be operated at any operating voltage
that is within specifications.
When the temperature circuit is operated in high range,
the device operating voltage, VDD, must be high
enough to ensure that the temperature circuit is cor-
rectly biased.
Table 14-1 shows the recommended minimum VDD vs.
range setting.
TABLE 14-1: RECOMMENDED VDD VS.
RANGE
14.3 Temperature Output
The output of the circuit is measured using the internal
Analog-to-Digital Converter. A channel is reserved for
the temperature circuit output. Refer to Section 15.0
“Analog-to-Digital Converter (ADC) Module” for
detailed information.
14.4 ADC Acquisition Time
To ensure accurate temperature measurements, the
user must wait at least 200 s after the ADC input
multiplexer is connected to the temperature indicator
output before the conversion is performed. In addition,
the user must wait 200 s between sequential
conversions of the temperature indicator output.
High Range: VOUT = VDD - 4VT
Low Range: VOUT = VDD - 2VT
Min. VDD, TSRNG = 1Min. VDD, TSRNG = 0
3.6V 1.8V
TSEN
TSRNG
VDD
VOUT To A D C
PIC16(L)F1508/9
DS41609A-page 134 Preliminary 2011 Microchip Technology Inc.
TABLE 14-2: SUMMARY OF REGISTERS ASSOCIATED WITH THE TEMPERATURE INDICATOR
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on page
FVRCON FVREN FVRRDY TSEN TSRNG CDAFVR<1:0> ADFVR<1:0> 118
Legend: Shaded cells are unused by the temperature indicator module.
2011 Microchip Technology Inc. Preliminary DS41609A-page 135
PIC16(L)F1508/9
15.0 ANALOG-TO-DIGITAL
CONVERTER (ADC) MODULE
The Analog-to-Digital Converter (ADC) allows
conversion of an analog input signal to a 10-bit binary
representation of that signal. This device uses analog
inputs, which are multiplexed into a single sample and
hold circuit. The output of the sample and hold is
connected to the input of the converter. The converter
generates a 10-bit binary result via successive
approximation and stores the conversion result into the
ADC result registers (ADRESH:ADRESL register pair).
Figure 15-1 shows the block diagram of the ADC.
The ADC voltage reference is software selectable to be
either internally generated or externally supplied.
The ADC can generate an interrupt upon completion of
a conversion. This interrupt can be used to wake-up the
device from Sleep.
FIGURE 15-1: ADC BLOCK DIAGRAM
VDD
VREF+ADPREF = 10
ADPREF = 00
FVR Buffer1
Note 1: When ADON = 0, all multiplexer inputs are disconnected.
ADON
GO/DONE
VSS
ADC
00000
00001
00010
00011
00100
00101
00111
00110
CHS<4:0>
AN0
VREF+/AN1
AN2
AN4
AN5
AN6
AN7
AN3
11111
ADRESH ADRESL
10
16
ADFM 0 = Left Justify
1 = Right Justify
DAC 11110
VREF- = VSS
VREF+
11101 Temp Indicator
Reserved 11100
Reserved 01100
01000
01001
01011
01010
AN8
AN9
AN10
AN11
PIC16(L)F1508/9
DS41609A-page 136 Preliminary 2011 Microchip Technology Inc.
15.1 ADC Configuration
When configuring and using the ADC the following
functions must be considered:
• Port configuration
• Channel selection
• ADC voltage reference selection
• ADC conversion clock source
• Interrupt control
• Result formatting
15.1.1 PORT CONFIGURATION
The ADC can be used to convert both analog and
digital signals. When converting analog signals, the I/O
pin should be configured for analog by setting the
associated TRIS and ANSEL bits. Refer to
Section 11.0 “I/O Ports” for more information.
15.1.2 CHANNEL SELECTION
There are 15 channel selections available:
•AN<11:0> pins
• Temperature Indicator
•DAC
• FVR (Fixed Voltage Reference) Output
Refer to Section 13.0 “Fixed Voltage Reference (FVR)”
and Section 14.0 “Temperature Indicator Module” for
more information on these channel selections.
The CHS bits of the ADCON0 register determine which
channel is connected to the sample and hold circuit.
When changing channels, a delay is required before
starting the next conversion. Refer to Section 15.2
“ADC Operation” for more information.
15.1.3 ADC VOLTAGE REFERENCE
The ADPREF bits of the ADCON1 register provides
control of the positive voltage reference. The positive
voltage reference can be:
•V
REF+ pin
•V
DD
See Section 13.0 “Fixed Voltage Reference (FVR)”
for more details on the Fixed Voltage Reference.
15.1.4 CONVERSION CLOCK
The source of the conversion clock is software select-
able via the ADCS bits of the ADCON1 register. There
are seven possible clock options:
•F
OSC/2
•F
OSC/4
•F
OSC/8
•F
OSC/16
•F
OSC/32
•F
OSC/64
•F
RC (dedicated internal oscillator)
The time to complete one bit conversion is defined as
TAD. One full 10-bit conversion requires 11.5 TAD peri-
ods as shown in Figure 15-2.
For correct conversion, the appropriate TAD specifica-
tion must be met. Refer to the A/D conversion require-
ments in Section 29.0 “Electrical Specifications” for
more information. Table 15-1 gives examples of appro-
priate ADC clock selections.
Note: Analog voltages on any pin that is defined
as a digital input may cause the input buf-
fer to conduct excess current.
Note: Unless using the FRC, any changes in the
system clock frequency will change the
ADC clock frequency, which may
adversely affect the ADC result.
2011 Microchip Technology Inc. Preliminary DS41609A-page 137
PIC16(L)F1508/9
TABLE 15-1: ADC CLOCK PERIOD (TAD) VS. DEVICE OPERATING FREQUENCIES
FIGURE 15-2: ANALOG-TO-DIGITAL CONVERSION TAD CYCLES
ADC Clock Period (TAD) Device Frequency (FOSC)
ADC
Clock Source ADCS<2:0> 20 MHz 16 MHz 8 MHz 4 MHz 1 MHz
Fosc/2 000 100 ns(2) 125 ns(2) 250 ns(2) 500 ns(2) 2.0 s
Fosc/4 100 200 ns(2) 250 ns(2) 500 ns(2) 1.0 s4.0 s
Fosc/8 001 400 ns(2) 0.5 s(2) 1.0 s2.0 s8.0 s(3)
Fosc/16 101 800 ns 1.0 s2.0 s4.0 s16.0 s(3)
Fosc/32 010 1.6 s2.0 s4.0 s8.0 s(3) 32.0 s(3)
Fosc/64 110 3.2 s4.0 s8.0 s(3) 16.0 s(3) 64.0 s(3)
FRC x11 1.0-6.0 s(1,4) 1.0-6.0 s(1,4) 1.0-6.0 s(1,4) 1.0-6.0 s(1,4) 1.0-6.0 s(1,4)
Legend: Shaded cells are outside of recommended range.
Note 1: The FRC source has a typical TAD time of 1.6 s for VDD.
2: These values violate the minimum required TAD time.
3: For faster conversion times, the selection of another clock source is recommended.
4: The ADC clock period (TAD) and total ADC conversion time can be minimized when the ADC clock is derived from the
system clock FOSC. However, the FRC clock source must be used when conversions are to be performed with the
device in Sleep mode.
TAD1 TAD2TAD3TAD4 TAD5TAD6 TAD7TAD8TAD11
Set GO bit
Holding capacitor is disconnected from analog input (typically 100 ns)
TAD9 TAD10
TCY - TAD
ADRESH:ADRESL is loaded, GO 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
On the following cycle:
PIC16(L)F1508/9
DS41609A-page 138 Preliminary 2011 Microchip Technology Inc.
15.1.5 INTERRUPTS
The ADC module allows for the ability to generate an
interrupt upon completion of an Analog-to-Digital
conversion. The ADC Interrupt Flag is the ADIF bit in
the PIR1 register. The ADC Interrupt Enable is the
ADIE bit in the PIE1 register. The ADIF bit must be
cleared in software.
This interrupt can be generated while the device is
operating or while in Sleep. If the device is in Sleep, the
interrupt will wake-up the device. Upon waking from
Sleep, the next instruction following the SLEEP instruc-
tion is always executed. If the user is attempting to
wake-up from Sleep and resume in-line code execu-
tion, the GIE and PEIE bits of the INTCON register
must be disabled. If the GIE and PEIE bits of the
INTCON register are enabled, execution will switch to
the Interrupt Service Routine.
15.1.6 RESULT FORMATTING
The 10-bit A/D conversion result can be supplied in two
formats, left justified or right justified. The ADFM bit of
the ADCON1 register controls the output format.
Figure 15-3 shows the two output formats.
FIGURE 15-3: 10-BIT A/D CONVERSION RESULT FORMAT
Note 1: The ADIF bit is set at the completion of
every conversion, regardless of whether
or not the ADC interrupt is enabled.
2: The ADC operates during Sleep only
when the FRC oscillator is selected.
ADRESH ADRESL
(ADFM = 0)MSB LSB
bit 7 bit 0 bit 7 bit 0
10-bit A/D Result Unimplemented: Read as ‘0’
(ADFM = 1)MSB LSB
bit 7 bit 0 bit 7 bit 0
Unimplemented: Read as ‘0’ 10-bit A/D Result
2011 Microchip Technology Inc. Preliminary DS41609A-page 139
PIC16(L)F1508/9
15.2 ADC Operation
15.2.1 STARTING A CONVERSION
To enable the ADC module, the ADON bit of the
ADCON0 register must be set to a ‘1’. Setting the GO/
DONE bit of the ADCON0 register to a ‘1’ will start the
Analog-to-Digital conversion.
15.2.2 COMPLETION OF A CONVERSION
When the conversion is complete, the ADC module will:
• Clear the GO/DONE bit
• Set the ADIF Interrupt Flag bit
• Update the ADRESH and ADRESL registers with
new conversion result
15.2.3 TERMINATING A CONVERSION
If a conversion must be terminated before completion,
the GO/DONE bit can be cleared in software. The
ADRESH and ADRESL registers will be updated with
the partially complete Analog-to-Digital conversion
sample. Incomplete bits will match the last bit
converted.
15.2.4 ADC OPERATION DURING SLEEP
The ADC module can operate during Sleep. This
requires the ADC clock source to be set to the FRC
option. When the FRC clock source is selected, the
ADC waits one additional instruction before starting the
conversion. This allows the SLEEP instruction to be
executed, which can reduce system noise during the
conversion. If the ADC interrupt is enabled, the device
will wake-up from Sleep when the conversion
completes. If the ADC interrupt is disabled, the ADC
module is turned off after the conversion completes,
although the ADON bit remains set.
When the ADC clock source is something other than
FRC, a SLEEP instruction causes the present conver-
sion to be aborted and the ADC module is turned off,
although the ADON bit remains set.
15.2.5 AUTO-CONVERSION TRIGGER
The auto-conversion trigger allows periodic ADC mea-
surements without software intervention. When a rising
edge of the selected source occurs, the GO/DONE bit
is set by hardware.
The auto-conversion trigger source is selected with the
TRIGSEL<3:0> bits of the ADCON2 register.
Using the auto-conversion trigger does not assure
proper ADC timing. It is the user’s responsibility to
ensure that the ADC timing requirements are met.
Auto-Conversion sources are:
•TMR0
•TMR1
•TMR2
•C1
•C2
•CLC1
•CLC2
•CLC3
•CLC4
Note: The GO/DONE bit should not be set in the
same instruction that turns on the ADC.
Refer to Section 15.2.6 “A/D Conver-
sion Procedure”.
Note: A device Reset forces all registers to their
Reset state. Thus, the ADC module is
turned off and any pending conversion is
terminated.
PIC16(L)F1508/9
DS41609A-page 140 Preliminary 2011 Microchip Technology Inc.
15.2.6 A/D CONVERSION PROCEDURE
This is an example procedure for using the ADC to
perform an Analog-to-Digital conversion:
1. Configure Port:
• Disable pin output driver (Refer to the TRIS
register)
• Configure pin as analog (Refer to the ANSEL
register)
2. Configure the ADC module:
• Select ADC conversion clock
• Configure voltage reference
• Select ADC input channel
• Turn on ADC module
3. Configure ADC interrupt (optional):
• Clear ADC interrupt flag
• Enable ADC interrupt
• Enable peripheral interrupt
• Enable global interrupt(1)
4. Wait the required acquisition time(2).
5. Start conversion by setting the GO/DONE bit.
6. Wait for ADC conversion to complete by one of
the following:
• Polling the GO/DONE bit
• Waiting for the ADC interrupt (interrupts
enabled)
7. Read ADC Result.
8. Clear the ADC interrupt flag (required if interrupt
is enabled).
EXAMPLE 15-1: A/D CONVERSION
Note 1: The global interrupt can be disabled if the
user is attempting to wake-up from Sleep
and resume in-line code execution.
2: Refer to Section 15.3 “A/D Acquisition
Requirements”.
;This code block configures the ADC
;for polling, Vdd and Vss references, Frc
;clock and AN0 input.
;
;Conversion start & polling for completion
; are included.
;
BANKSEL ADCON1 ;
MOVLW B’11110000’ ;Right justify, Frc
;clock
MOVWF ADCON1 ;Vdd and Vss Vref+
BANKSEL TRISA ;
BSF TRISA,0 ;Set RA0 to input
BANKSEL ANSEL ;
BSF ANSEL,0 ;Set RA0 to analog
BANKSEL ADCON0 ;
MOVLW B’00000001’ ;Select channel AN0
MOVWF ADCON0 ;Turn ADC On
CALL SampleTime ;Acquisiton delay
BSF ADCON0,ADGO ;Start conversion
BTFSC ADCON0,ADGO ;Is conversion done?
GOTO $-1 ;No, test again
BANKSEL ADRESH ;
MOVF ADRESH,W ;Read upper 2 bits
MOVWF RESULTHI ;store in GPR space
BANKSEL ADRESL ;
MOVF ADRESL,W ;Read lower 8 bits
MOVWF RESULTLO ;Store in GPR space
2011 Microchip Technology Inc. Preliminary DS41609A-page 141
PIC16(L)F1508/9
15.2.7 ADC REGISTER DEFINITIONS
The following registers are used to control the
operation of the ADC.
REGISTER 15-1: ADCON0: A/D CONTROL REGISTER 0
U-0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
— CHS<4:0> GO/DONE ADON
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 Unimplemented: Read as ‘0’
bit 6-2 CHS<4:0>: Analog Channel Select bits
00000 =AN0
00001 =AN1
00010 =AN2
00011 =AN3
00100 =AN4
00101 =AN5
00110 =AN6
00111 =AN7
01000 =AN8
01001 =AN9
01010 =AN10
01011 =AN11
01100 = Reserved. No channel connected.
•
•
•
11100 = Reserved. No channel connected.
11101 = Temperature Indicator(1)
11110 = DAC (Digital-to-Analog Converter)(2)
11111 = FVR (Fixed Voltage Reference) Buffer 1 Output(3)
bit 1 GO/DONE: A/D Conversion Status bit
1 = A/D conversion cycle in progress. Setting this bit starts an A/D conversion cycle.
This bit is automatically cleared by hardware when the A/D conversion has completed.
0 = A/D conversion completed/not in progress
bit 0 ADON: ADC Enable bit
1 = ADC is enabled
0 = ADC is disabled and consumes no operating current
Note 1: See Section 14.0 “Temperature Indicator Module” for more information.
2: See Section 16.0 “Digital-to-Analog Converter (DAC) Module” for more information.
3: See Section 13.0 “Fixed Voltage Reference (FVR)” for more information.
PIC16(L)F1508/9
DS41609A-page 142 Preliminary 2011 Microchip Technology Inc.
REGISTER 15-2: ADCON1: A/D CONTROL REGISTER 1
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 U-0 U-0 R/W-0/0 R/W-0/0
ADFM ADCS<2:0> —— ADPREF<1:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 ADFM: A/D Result Format Select bit
1 = Right justified. Six Most Significant bits of ADRESH are set to ‘0’ when the conversion result is
loaded.
0 = Left justified. Six Least Significant bits of ADRESL are set to ‘0’ when the conversion result is
loaded.
bit 6-4 ADCS<2:0>: A/D Conversion Clock Select bits
000 =F
OSC/2
001 =F
OSC/8
010 =F
OSC/32
011 =F
RC (clock supplied from a dedicated RC oscillator)
100 =F
OSC/4
101 =F
OSC/16
110 =F
OSC/64
111 =F
RC (clock supplied from a dedicated RC oscillator)
bit 3-2 Unimplemented: Read as ‘0’
bit 1-0 ADPREF<1:0>: A/D Positive Voltage Reference Configuration bits
00 =V
REF+ is connected to VDD
01 = Reserved
10 =V
REF+ is connected to external VREF+ pin(1)
11 = Reserved
Note 1: When selecting the VREF+ pin as the source of the positive reference, be aware that a minimum voltage
specification exists. See Section 29.0 “Electrical Specifications” for details.
2011 Microchip Technology Inc. Preliminary DS41609A-page 143
PIC16(L)F1508/9
REGISTER 15-3: ADCON2: A/D CONTROL REGISTER 2
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 U-0 U-0 U-0 U-0
TRIGSEL<3:0> — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 TRIGSEL<3:0>: Auto-Conversion Trigger Selection bits(1)
0000 = No auto-conversion trigger selected
0001 =Reserved
0010 =Reserved
0011 = TMR0 Overflow(2)
0100 = TMR1 Overflow(2)
0101 = TMR2 Match to PR2(2)
0110 = SYNCC1OUT
0111 = SYNCC2OUT
1000 =CLC1
1001 =CLC2
1010 =CLC3
1011 =CLC4
1100 =Reserved
1101 =Reserved
1110 =Reserved
1111 = Reserved
bit 3-0 Unimplemented: Read as ‘0’
Note 1: This is a rising edge sensitive input for all sources.
2: Signal also sets its corresponding interrupt flag.
PIC16(L)F1508/9
DS41609A-page 144 Preliminary 2011 Microchip Technology Inc.
REGISTER 15-4: ADRESH: ADC RESULT REGISTER HIGH (ADRESH) ADFM = 0
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
ADRES<9:2>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 ADRES<9:2>: ADC Result Register bits
Upper 8 bits of 10-bit conversion result
REGISTER 15-5: ADRESL: ADC RESULT REGISTER LOW (ADRESL) ADFM = 0
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
ADRES<1:0> — — — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 ADRES<1:0>: ADC Result Register bits
Lower 2 bits of 10-bit conversion result
bit 5-0 Reserved: Do not use.
2011 Microchip Technology Inc. Preliminary DS41609A-page 145
PIC16(L)F1508/9
REGISTER 15-6: ADRESH: ADC RESULT REGISTER HIGH (ADRESH) ADFM = 1
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
— — — — — — ADRES<9:8>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-2 Reserved: Do not use.
bit 1-0 ADRES<9:8>: ADC Result Register bits
Upper 2 bits of 10-bit conversion result
REGISTER 15-7: ADRESL: ADC RESULT REGISTER LOW (ADRESL) ADFM = 1
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
ADRES<7:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 ADRES<7:0>: ADC Result Register bits
Lower 8 bits of 10-bit conversion result
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DS41609A-page 146 Preliminary 2011 Microchip Technology Inc.
15.3 A/D Acquisition Requirements
For the ADC 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 15-4. 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), refer
to Figure 15-4. The maximum recommended
impedance for analog sources is 10 k. As the
source impedance is decreased, the acquisition time
may be decreased. After the analog input channel is
selected (or changed), an A/D acquisition must be
done before the conversion can be started. To calculate
the minimum acquisition time, Equation 15-1 may be
used. This equation assumes that 1/2 LSb error is used
(1,024 steps for the ADC). The 1/2 LSb error is the
maximum error allowed for the ADC to meet its
specified resolution.
EQUATION 15-1: ACQUISITION TIME EXAMPLE
TACQ Amplifier Settling Time Hold Capacitor Charging Time Temperature Coefficient++=
TAMP TCTCOFF++=
2µs TCTemperature - 25°C0.05µs/°C++=
TCCHOLD RIC RSS RS++ ln(1/2047)–=
12.5pF 1k
7k
10k
++– ln(0.0004885)=
1.12=µs
VAPPLIED 1e
Tc–
RC
---------
–



VAPPLIED 11
2n1+
1–
--------------------------–


=
VAPPLIED 11
2n1+
1–
--------------------------
–


VCHOLD=
VAPPLIED 1e
TC–
RC
----------
–



VCHOLD=
;[1] VCHOLD charged to within 1/2 lsb
;[2] VCHOLD charge response to VAPPLIED
;combining [1] and [2]
The value for TC can be approximated with the following equations:
Solving for TC:
Therefore:
Temperature 50°C and external impedance of 10k
5.0V VDD=
Assumptions:
Note: Where n = number of bits of the ADC.
TACQ 5µs 1.12µs 50°C- 25°C0.05µs/°C++=
7.37µs=
Note 1: The reference voltage (VREF+) has no effect on the equation, since it cancels itself out.
2: The charge holding capacitor (CHOLD) is not discharged after each conversion.
3: The maximum recommended impedance for analog sources is 10 k. This is required to meet the pin
leakage specification.
2011 Microchip Technology Inc. Preliminary DS41609A-page 147
PIC16(L)F1508/9
FIGURE 15-4: ANALOG INPUT MODEL
FIGURE 15-5: ADC TRANSFER FUNCTION
CPIN
VA
Rs
Analog
5 pF
VDD
VT 0.6V
VT 0.6V I LEAKAGE(1)
RIC 1k
Sampling
Switch
SS Rss
CHOLD = 10 pF
VREF-
6V
Sampling Switch
5V
4V
3V
2V
567891011
(k)
VDD
Legend:
CPIN
VT
I LEAKAGE
RIC
SS
CHOLD
= Input Capacitance
= Threshold Voltage
= Leakage current at the pin due to
= Interconnect Resistance
= Sampling Switch
= Sample/Hold Capacitance
various junctions
RSS
Note 1: Refer to Section 29.0 “Electrical Specifications”.
RSS = Resistance of Sampling Switch
Input
pin
3FFh
3FEh
ADC Output Code
3FDh
3FCh
03h
02h
01h
00h
Full-Scale
3FBh
0.5 LSB
VREF-Zero-Scale
Transition VREF+
Transition
1.5 LSB
Full-Scale Range
Analog Input Voltage
PIC16(L)F1508/9
DS41609A-page 148 Preliminary 2011 Microchip Technology Inc.
TABLE 15-2: SUMMARY OF REGISTERS ASSOCIATED WITH ADC
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
ADCON0 — CHS<4:0> GO/DONE ADON 141
ADCON1 ADFM ADCS<2:0> —— ADPREF<1:0> 142
ADCON2 TRIGSEL<3:0> — — — — 143
ADRESH A/D Result Register High 144, 145
ADRESL A/D Result Register Low 144, 145
ANSELA ———ANSA4— ANSA2 ANSA1 ANSA0 115
ANSELB —— ANSB5 ANSB4 — — — — 119
ANSELC ANSC7 ANSC6 —— ANSC3 ANSC2 ANSC1 ANSC0 123
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IE TMR1IE 79
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
TRISA — — TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
TRISB TRISB7 TRISB6 TRISB5 TRISB4 — — — — 118
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
FVRCON FVREN FVRRDY TSEN TSRNG CDAFVR<1:0> ADFVR<1:0> 132
Legend: x = unknown, u = unchanged, — = unimplemented read as ‘0’, q = value depends on condition. Shaded cells are not
used for ADC module.
Note 1: Unimplemented, read as ‘1’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 149
PIC16(L)F1508/9
16.0 DIGITAL-TO-ANALOG
CONVERTER (DAC) MODULE
The Digital-to-Analog Converter supplies a variable
voltage reference, ratiometric with the input source,
with 32 selectable output levels.
The input of the DAC can be connected to:
•External V
REF+ pin
•V
DD supply voltage
The output of the DAC can be configured to supply a
reference voltage to the following:
• Comparator positive input
• ADC input channel
•DACOUT1 pin
•DACOUT2 pin
The Digital-to-Analog Converter (DAC) can be enabled
by setting the DACEN bit of the DACCON0 register.
16.1 Output Voltage Selection
The DAC has 32 voltage level ranges. The 32 levels
are set with the DACR<4:0> bits of the DACCON1
register.
The DAC output voltage is determined by the following
equations:
EQUATION 16-1: DAC OUTPUT VOLTAGE
16.2 Ratiometric Output Level
The DAC output value is derived using a resistor ladder
with each end of the ladder tied to a positive and
negative voltage reference input source. If the voltage
of either input source fluctuates, a similar fluctuation will
result in the DAC output value.
The value of the individual resistors within the ladder
can be found in Section 29.0 “Electrical
Specifications”.
16.3 DAC Voltage Reference Output
The DAC voltage can be output to the DACOUT1 and
DACOUT2 pins by setting the respective DACOE1 and
DACOE2 pins of the DACCON0 register. Selecting the
DAC reference voltage for output on either DACOUTx
pin automatically overrides the digital output buffer and
digital input threshold detector functions of that pin.
Reading the DACOUTx pin when it has been config-
ured for DAC reference voltage output will always
return a ‘0’.
Due to the limited current drive capability, a buffer must
be used on the DAC voltage reference output for
external connections to either DACOUTx pin.
Figure 16-2 shows an example buffering technique.
IF DACEN = 1
IF DACEN = 0 and DACLPS = 1 and DACR[4:0] = 11111
VOUT VSOURCE +=
IF DACEN = 0 and DACLPS = 0 and DACR[4:0] = 00000
VOUT VSOURCE –=
VSOURCE+ = VDD, VREF, or FVR BUFFER 2
VSOURCE- = VSS
VOUT VSOURCE+VSOURCE-–
DACR 4:0
25
-----------------------------


VSOURCE-+=
PIC16(L)F1508/9
DS41609A-page 150 Preliminary 2011 Microchip Technology Inc.
FIGURE 16-1: DIGITAL-TO-ANALOG CONVERTER BLOCK DIAGRAM
FIGURE 16-2: VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE
32-to-1 MUX
DACR<4:0>
R
R
R
R
R
R
R
32 DAC
DACOUT1
5
(To Comparator and
ADC Module)
DACOE1
VDD
VREF+
DACPSS
DACEN
Steps
Digital-to-Analog Converter (DAC)
R
VSOURCE-
VSOURCE+
DACOUT2
DACOE2
DACOUTXBuffered DAC Output
+
–
DAC
Module
Voltage
Reference
Output
Impedance
R
PIC® MCU
2011 Microchip Technology Inc. Preliminary DS41609A-page 151
PIC16(L)F1508/9
16.4 Operation During Sleep
When the device wakes up from Sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the DACCON0 register are not affected. To minimize
current consumption in Sleep mode, the voltage
reference should be disabled.
16.5 Effects of a Reset
A device Reset affects the following:
• DAC is disabled.
• DAC output voltage is removed from the
DACOUT pin.
• The DACR<4:0> range select bits are cleared.
PIC16(L)F1508/9
DS41609A-page 152 Preliminary 2011 Microchip Technology Inc.
16.6 DAC Control Registers
TABLE 16-1: SUMMARY OF REGISTERS ASSOCIATED WITH THE DAC MODULE
REGISTER 16-1: DACCON0: VOLTAGE REFERENCE CONTROL REGISTER 0
R/W-0/0 U-0 R/W-0/0 R/W-0/0 U-0 R/W-0/0 U-0 U-0
DACEN — DACOE1 DACOE2 —DACPSS — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 DACEN: DAC Enable bit
1 = DAC is enabled
0 = DAC is disabled
bit 6 Unimplemented: Read as ‘0’
bit 5 DACOE1: DAC Voltage Output Enable bit
1 = DAC voltage level is also an output on the DACOUT1 pin
0 = DAC voltage level is disconnected from the DACOUT1 pin
bit 4 DACOE2: DAC Voltage Output Enable bit
1 = DAC voltage level is also an output on the DACOUT2 pin
0 = DAC voltage level is disconnected from the DACOUT2 pin
bit 3 Unimplemented: Read as ‘0’
bit 2 DACPSS: DAC Positive Source Select bit
1 =VREF+ pin
0 =VDD
bit 1-0 Unimplemented: Read as ‘0’
REGISTER 16-2: DACCON1: VOLTAGE REFERENCE CONTROL REGISTER 1
U-0 U-0 U-0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
— — — DACR<4:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-5 Unimplemented: Read as ‘0’
bit 4-0 DACR<4:0>: DAC Voltage Output Select bits
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on page
FVRCON FVREN FVRRDY TSEN TSRNG CDAFVR<1:0> ADFVR<1:0> 161
DACCON0 DACEN — DACOE1 DACOE2 —DACPSS— — 152
DACCON1 — — — DACR<4:0> 152
Legend: — = Unimplemented location, read as ‘0’. Shaded cells are not used with the DAC module.
2011 Microchip Technology Inc. Preliminary DS41609A-page 153
PIC16(L)F1508/9
17.0 COMPARATOR MODULE
Comparators are used to interface analog circuits to a
digital circuit by comparing two analog voltages and
providing a digital indication of their relative magnitudes.
Comparators are very useful mixed signal building
blocks because they provide analog functionality
independent of program execution. The analog
comparator module includes the following features:
• Independent comparator control
• Programmable input selection
• Comparator output is available internally/externally
• Programmable output polarity
• Interrupt-on-change
• Wake-up from Sleep
• Programmable Speed/Power optimization
•PWM shutdown
• Programmable and Fixed Voltage Reference
17.1 Comparator Overview
A single comparator is shown in Figure 17-1 along with
the relationship between the analog input levels and
the digital output. When the analog voltage at VIN+ is
less than the analog voltage at VIN-, the output of the
comparator is a digital low level. When the analog
voltage at VIN+ is greater than the analog voltage at
VIN-, the output of the comparator is a digital high level.
FIGURE 17-1: SINGLE COMPARATOR
–
+
VIN+
VIN-Output
Output
VIN+
VIN-
Note: The black areas of the output of the
comparator represents the uncertainty
due to input offsets and response time.
PIC16(L)F1508/9
DS41609A-page 154 Preliminary 2011 Microchip Technology Inc.
FIGURE 17-2: COMPARATOR MODULES SIMPLIFIED BLOCK DIAGRAM
Note 1: When CxON = 0, the Comparator will produce a ‘0’ at the output
2: When CxON = 0, all multiplexer inputs are disconnected.
MUX
Cx
0
1
2
3
CxON(1)
CxNCH<2:0>
3
0
1
CXPCH<1:0>
C12IN1-
C12IN2-
C12IN3-
CXIN+
MUX
-
+
CxVN
CxVP
CXOUT
Q1
D
EN
Q
CXPOL
MCXOUT
Set CxIF
0
1
CXSYNC CXOE
CXOUT
DQ
SYNCCXOUT
DAC
FVR Buffer2
C12IN0-
2
CxSP
CxHYS
det
Interrupt
det
Interrupt
CxINTN
CxINTP
2
3
TRIS bit
CxON
(2)
(2)
(from Timer1)
T1CLK
To Tim er1 ,
4
FVR Buffer2
To CWG
async_CxOUT
CLCx, ADC
2011 Microchip Technology Inc. Preliminary DS41609A-page 155
PIC16(L)F1508/9
17.2 Comparator Control
Each comparator has 2 control registers: CMxCON0 and
CMxCON1.
The CMxCON0 registers (see Register 17-1) contain
Control and Status bits for the following:
• Enable
•Output selection
• Output polarity
• Speed/Power selection
• Hysteresis enable
• Output synchronization
The CMxCON1 registers (see Register 17-2) contain
Control bits for the following:
• Interrupt enable
• Interrupt edge polarity
• Positive input channel selection
• Negative input channel selection
17.2.1 COMPARATOR ENABLE
Setting the CxON bit of the CMxCON0 register enables
the comparator for operation. Clearing the CxON bit
disables the comparator resulting in minimum current
consumption.
17.2.2 COMPARATOR OUTPUT
SELECTION
The output of the comparator can be monitored by
reading either the CxOUT bit of the CMxCON0 register
or the MCxOUT bit of the CMOUT register. In order to
make the output available for an external connection,
the following conditions must be true:
• CxOE bit of the CMxCON0 register must be set
• Corresponding TRIS bit must be cleared
• CxON bit of the CMxCON0 register must be set
17.2.3 COMPARATOR OUTPUT POLARITY
Inverting the output of the comparator is functionally
equivalent to swapping the comparator inputs. The
polarity of the comparator output can be inverted by
setting the CxPOL bit of the CMxCON0 register.
Clearing the CxPOL bit results in a non-inverted output.
Table 17-1 shows the output state versus input
conditions, including polarity control.
17.2.4 COMPARATOR SPEED/POWER
SELECTION
The trade-off between speed or power can be opti-
mized during program execution with the CxSP control
bit. The default state for this bit is ‘1’ which selects the
normal speed mode. Device power consumption can
be optimized at the cost of slower comparator propaga-
tion delay by clearing the CxSP bit to ‘0’.
Note 1: The CxOE bit of the CMxCON0 register
overrides the PORT data latch. Setting
the CxON bit of the CMxCON0 register
has no impact on the port override.
2: The internal output of the comparator is
latched with each instruction cycle.
Unless otherwise specified, external
outputs are not latched.
TABLE 17-1: COMPARATOR OUTPUT
STATE VS. INPUT
CONDITIONS
Input Condition CxPOL CxOUT
CxVN > CxVP00
CxVN < CxVP01
CxVN > CxVP11
CxVN < CxVP10
PIC16(L)F1508/9
DS41609A-page 156 Preliminary 2011 Microchip Technology Inc.
17.3 Comparator Hysteresis
A selectable amount of separation voltage can be
added to the input pins of each comparator to provide a
hysteresis function to the overall operation. Hysteresis
is enabled by setting the CxHYS bit of the CMxCON0
register.
See Section 29.0 “Electrical Specifications” for
more information.
17.4 Timer1 Gate Operation
The output resulting from a comparator operation can
be used as a source for gate control of Timer1. See
Section 19.5 “Timer1 Gate” for more information.
This feature is useful for timing the duration or interval
of an analog event.
It is recommended that the comparator output be syn-
chronized to Timer1. This ensures that Timer1 does not
increment while a change in the comparator is occur-
ring.
17.4.1 COMPARATOR OUTPUT
SYNCHRONIZATION
The output from either comparator, C1 or C2, can be
synchronized with Timer1 by setting the CxSYNC bit of
the CMxCON0 register.
Once enabled, the comparator output is latched on the
falling edge of the Timer1 source clock. If a prescaler is
used with Timer1, the comparator output is latched after
the prescaling function. To prevent a race condition, the
comparator output is latched on the falling edge of the
Timer1 clock source and Timer1 increments on the
rising edge of its clock source. See the Comparator
Block Diagram (Figure 17-2) and the Timer1 Block
Diagram (Figure 19-1) for more information.
17.5 Comparator Interrupt
An interrupt can be generated upon a change in the
output value of the comparator for each comparator, a
rising edge detector and a falling edge detector are
present.
When either edge detector is triggered and its associ-
ated enable bit is set (CxINTP and/or CxINTN bits of
the CMxCON1 register), the Corresponding Interrupt
Flag bit (CxIF bit of the PIR2 register) will be set.
To enable the interrupt, you must set the following bits:
• CxON, CxPOL and CxSP bits of the CMxCON0
register
• CxIE bit of the PIE2 register
• CxINTP bit of the CMxCON1 register (for a rising
edge detection)
• CxINTN bit of the CMxCON1 register (for a falling
edge detection)
• PEIE and GIE bits of the INTCON register
The associated interrupt flag bit, CxIF bit of the PIR2
register, must be cleared in software. If another edge is
detected while this flag is being cleared, the flag will still
be set at the end of the sequence.
17.6 Comparator Positive Input
Selection
Configuring the CxPCH<1:0> bits of the CMxCON1
register directs an internal voltage reference or an
analog pin to the non-inverting input of the comparator:
• CxIN+ analog pin
•DAC
• FVR (Fixed Voltage Reference)
•V
SS (Ground)
See Section 13.0 “Fixed Voltage Reference (FVR)”
for more information on the Fixed Voltage Reference
module.
See Section 16.0 “Digital-to-Analog Converter
(DAC) Module” for more information on the DAC input
signal.
Any time the comparator is disabled (CxON = 0), all
comparator inputs are disabled.
Note: Although a comparator is disabled, an
interrupt can be generated by changing
the output polarity with the CxPOL bit of
the CMxCON0 register, or by switching
the comparator on or off with the CxON bit
of the CMxCON0 register.
2011 Microchip Technology Inc. Preliminary DS41609A-page 157
PIC16(L)F1508/9
17.7 Comparator Negative Input
Selection
The CxNCH<2:0> bits of the CMxCON0 register direct
one of the input sources to the comparator inverting
input.
17.8 Comparator Response Time
The comparator output is indeterminate for a period of
time after the change of an input source or the selection
of a new reference voltage. This period is referred to as
the response time. The response time of the comparator
differs from the settling time of the voltage reference.
Therefore, both of these times must be considered when
determining the total response time to a comparator
input change. See the Comparator and Voltage Refer-
ence Specifications in Section 29.0 “Electrical Specifi-
cations” for more details.
17.9 Interaction with ECCP Logic
The C1 and C2 comparators can be used as general
purpose comparators. Their outputs can be brought
out to the C1OUT and C2OUT pins. When the ECCP
Auto-Shutdown is active it can use one or both
comparator signals. If auto-restart is also enabled, the
comparators can be configured as a closed loop
analog feedback to the ECCP, thereby, creating an
analog controlled PWM.
17.10 Analog Input Connection
Considerations
A simplified circuit for an analog input is shown in
Figure 17-3. Since the analog input pins share their
connection with a digital input, they have reverse
biased ESD protection 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 for-
ward biased and a latch-up may occur.
A maximum source impedance of 10 k is recommended
for the analog sources. Also, any external component
connected to an analog input pin, such as a capacitor or
a Zener diode, should have very little leakage current to
minimize inaccuracies introduced.
Note: To use CxIN+ and CxINx- pins as analog
input, the appropriate bits must be set in
the ANSEL register and the correspond-
ing TRIS bits must also be set to disable
the output drivers.
Note: When the comparator module is first
initialized the output state is unknown.
Upon initialization, the user should verify
the output state of the comparator prior to
relying on the result, primarily when using
the result in connection with other
peripheral features, such as the ECCP
Auto-Shutdown mode.
Note 1: When reading a PORT register, all pins
configured as analog inputs will read as a
‘0’. Pins configured as digital inputs will
convert as an analog input, according to
the input specification.
2: Analog levels on any pin defined as a
digital input, may cause the input buffer to
consume more current than is specified.
PIC16(L)F1508/9
DS41609A-page 158 Preliminary 2011 Microchip Technology Inc.
FIGURE 17-3: ANALOG INPUT MODEL
VA
Rs < 10K
CPIN
5 pF
VDD
VT 0.6V
VT 0.6V
RIC
ILEAKAGE(1)
Vss
Legend: CPIN = Input Capacitance
ILEAKAGE = Leakage Current at the pin due to various junctions
RIC = Interconnect Resistance
RS= Source Impedance
VA= Analog Voltage
VT= Threshold Voltage
To Comparator
Note 1: See Section 29.0 “Electrical Specifications”.
Analog
Input
pin
2011 Microchip Technology Inc. Preliminary DS41609A-page 159
PIC16(L)F1508/9
REGISTER 17-1: CMxCON0: COMPARATOR Cx CONTROL REGISTER 0
R/W-0/0 R-0/0 R/W-0/0 R/W-0/0 U-0 R/W-1/1 R/W-0/0 R/W-0/0
CxON CxOUT CxOE CxPOL —CxSP CxHYS CxSYNC
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 CxON: Comparator Enable bit
1 = Comparator is enabled and consumes no active power
0 = Comparator is disabled
bit 6 CxOUT: Comparator Output bit
If CxPOL = 1 (inverted polarity):
1 = CxVP < CxVN
0 = CxVP > CxVN
If CxPOL = 0 (non-inverted polarity):
1 = CxVP > CxVN
0 = CxVP < CxVN
bit 5 CxOE: Comparator Output Enable bit
1 = CxOUT is present on the CxOUT pin. Requires that the associated TRIS bit be cleared to actually
drive the pin. Not affected by CxON.
0 = CxOUT is internal only
bit 4 CxPOL: Comparator Output Polarity Select bit
1 = Comparator output is inverted
0 = Comparator output is not inverted
bit 3 Unimplemented: Read as ‘0’
bit 2 CxSP: Comparator Speed/Power Select bit
1 = Comparator operates in normal power, higher speed mode
0 = Comparator operates in low-power, low-speed mode
bit 1 CxHYS: Comparator Hysteresis Enable bit
1 = Comparator hysteresis enabled
0 = Comparator hysteresis disabled
bit 0 CxSYNC: Comparator Output Synchronous Mode bit
1 = Comparator output to Timer1 and I/O pin is synchronous to changes on Timer1 clock source.
Output updated on the falling edge of Timer1 clock source.
0 = Comparator output to Timer1 and I/O pin is asynchronous
PIC16(L)F1508/9
DS41609A-page 160 Preliminary 2011 Microchip Technology Inc.
REGISTER 17-2: CMxCON1: COMPARATOR Cx CONTROL REGISTER 1
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 U-0 R/W-0/0 R/W-0/0 R/W-0/0
CxINTP CxINTN CxPCH<1:0> —CxNCH<2:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 CxINTP: Comparator Interrupt on Positive Going Edge Enable bits
1 = The CxIF interrupt flag will be set upon a positive going edge of the CxOUT bit
0 = No interrupt flag will be set on a positive going edge of the CxOUT bit
bit 6 CxINTN: Comparator Interrupt on Negative Going Edge Enable bits
1 = The CxIF interrupt flag will be set upon a negative going edge of the CxOUT bit
0 = No interrupt flag will be set on a negative going edge of the CxOUT bit
bit 5-4 CxPCH<1:0>: Comparator Positive Input Channel Select bits
11 = CxVP connects to VSS
10 = CxVP connects to FVR Voltage Reference
01 = CxVP connects to DAC Voltage Reference
00 = CxVP connects to CxIN+ pin
bit 3 Unimplemented: Read as ‘0’
bit 2-0 CxNCH<2:0>: Comparator Negative Input Channel Select bits
111 = Reserved
110 = Reserved
101 = Reserved
100 = CxVN connects to FVR Voltage reference
011 = CxVN connects to C12IN3- pin
010 = CxVN connects to C12IN2- pin
001 = CxVN connects to C12IN1- pin
000 = CxVN connects to C12IN0- pin
REGISTER 17-3: CMOUT: COMPARATOR OUTPUT REGISTER
U-0 U-0 U-0 U-0 U-0 U-0 R-0/0 R-0/0
— — — — — — MC2OUT MC1OUT
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-2 Unimplemented: Read as ‘0’
bit 1 MC2OUT: Mirror Copy of C2OUT bit
bit 0 MC1OUT: Mirror Copy of C1OUT bit
2011 Microchip Technology Inc. Preliminary DS41609A-page 161
PIC16(L)F1508/9
TABLE 17-2: SUMMARY OF REGISTERS ASSOCIATED WITH COMPARATOR MODULE
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
ANSELA — — — ANSA4 — ANSA2 ANSA1 ANSA0 115
ANSELC ANSC7 ANSC6 —— ANSC3 ANSC2 ANSC1 ANSC0 123
CM1CON0 C1ON C1OUT C1OE C1POL — C1SP C1HYS C1SYNC 159
CM2CON0 C2ON C2OUT C2OE C2POL — C2SP C2HYS C2SYNC 159
CM1CON1 C1NTP C1INTN C1PCH<1:0> — C1NCH<2:0> 160
CM2CON1 C2NTP C2INTN C2PCH<1:0> — C2NCH<2:0> 160
CMOUT — — — — — — MC2OUT MC1OUT 160
DACCON0 DACEN — DACOE1 DACOE2 —DACPSS— — 152
DACCON1 — — — DACR<4:0> 152
FVRCON FVREN FVRRDY TSEN TSRNG CDAFVR<1:0> ADFVR<1:0> 132
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE2 OSFIE C2IE C1IE —BCL1IE NCO1IE — — 80
PIR2 OSFIF C2IF C1IF —BCL1IF NCO1IF — — 83
PORTA — — RA5 RA4 RA3 RA2 RA1 RA0 114
PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 122
LATA — — LATA5 LATA4 — LATA2 LATA1 LATA0 115
LATC LATC7 LATC6 LATC5 LATC4 LATC3 LATC2 LATC1 LATC0 122
TRISA — — TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
Legend: — = unimplemented location, read as ‘0’. Shaded cells are unused by the comparator module.
Note 1: Unimplemented, read as ‘1’.
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NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 163
PIC16(L)F1508/9
18.0 TIMER0 MODULE
The Timer0 module is an 8-bit timer/counter with the
following features:
• 8-bit timer/counter register (TMR0)
• 8-bit prescaler (independent of Watchdog Timer)
• Programmable internal or external clock source
• Programmable external clock edge selection
• Interrupt on overflow
• TMR0 can be used to gate Timer1
Figure 18-1 is a block diagram of the Timer0 module.
18.1 Timer0 Operation
The Timer0 module can be used as either an 8-bit timer
or an 8-bit counter.
18.1.1 8-BIT TIMER MODE
The Timer0 module will increment every instruction
cycle, if used without a prescaler. 8-Bit Timer mode is
selected by clearing the TMR0CS bit of the
OPTION_REG register.
When TMR0 is written, the increment is inhibited for
two instruction cycles immediately following the write.
18.1.2 8-BIT COUNTER MODE
In 8-Bit Counter mode, the Timer0 module will increment
on every rising or falling edge of the T0CKI pin.
8-Bit Counter mode using the T0CKI pin is selected by
setting the TMR0CS bit in the OPTION_REG register to
‘1’.
The rising or falling transition of the incrementing edge
for either input source is determined by the TMR0SE bit
in the OPTION_REG register.
FIGURE 18-1: BLOCK DIAGRAM OF THE TIMER0
Note: The value written to the TMR0 register
can be adjusted, in order to account for
the two instruction cycle delay when
TMR0 is written.
T0CKI
TMR0SE
TMR0
PS<2:0>
Data Bus
Set Flag bit TMR0IF
on Overflow
TMR0CS
0
1
0
1
8
8
8-bit
Prescaler
FOSC/4
PSA
Sync
2 TCY
Overflow to Timer1
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18.1.3 SOFTWARE PROGRAMMABLE
PRESCALER
A software programmable prescaler is available for
exclusive use with Timer0. The prescaler is enabled by
clearing the PSA bit of the OPTION_REG register.
There are 8 prescaler options for the Timer0 module
ranging from 1:2 to 1:256. The prescale values are
selectable via the PS<2:0> bits of the OPTION_REG
register. In order to have a 1:1 prescaler value for the
Timer0 module, the prescaler must be disabled by set-
ting the PSA bit of the OPTION_REG register.
The prescaler is not readable or writable. All instructions
writing to the TMR0 register will clear the prescaler.
18.1.4 TIMER0 INTERRUPT
Timer0 will generate an interrupt when the TMR0
register overflows from FFh to 00h. The TMR0IF
interrupt flag bit of the INTCON register is set every
time the TMR0 register overflows, regardless of
whether or not the Timer0 interrupt is enabled. The
TMR0IF bit can only be cleared in software. The Timer0
interrupt enable is the TMR0IE bit of the INTCON
register.
18.1.5 8-BIT COUNTER MODE
SYNCHRONIZATION
When in 8-Bit Counter mode, the incrementing edge on
the T0CKI pin must be synchronized to the instruction
clock. Synchronization can be accomplished by
sampling the prescaler output on the Q2 and Q4 cycles
of the instruction clock. The high and low periods of the
external clocking source must meet the timing
requirements as shown in Section 29.0 “Electrical
Specifications”.
18.1.6 OPERATION DURING SLEEP
Timer0 cannot operate while the processor is in Sleep
mode. The contents of the TMR0 register will remain
unchanged while the processor is in Sleep mode.
Note: The Watchdog Timer (WDT) uses its own
independent prescaler.
Note: The Timer0 interrupt cannot wake the
processor from Sleep since the timer is
frozen during Sleep.
2011 Microchip Technology Inc. Preliminary DS41609A-page 165
PIC16(L)F1508/9
18.2 Option and Timer0 Control Register
TABLE 18-1: SUMMARY OF REGISTERS ASSOCIATED WITH TIMER0
REGISTER 18-1: OPTION_REG: OPTION REGISTER
R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1
WPUEN INTEDG TMR0CS TMR0SE PSA PS<2:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 WPUEN: Weak Pull-Up Enable bit
1 = All weak pull-ups are disabled (except MCLR, if it is enabled)
0 = Weak pull-ups are enabled by individual WPUx latch values
bit 6 INTEDG: Interrupt Edge Select bit
1 = Interrupt on rising edge of INT pin
0 = Interrupt on falling edge of INT pin
bit 5 TMR0CS: Timer0 Clock Source Select bit
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock (FOSC/4)
bit 4 TMR0SE: 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: Prescaler Assignment bit
1 = Prescaler is not assigned to the Timer0 module
0 = Prescaler is assigned to the Timer0 module
bit 2-0 PS<2:0>: Prescaler Rate Select bits
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
ADCON2 TRIGSEL<3:0> — — — — 143
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
OPTION_REG WPUEN INTEDG TMR0CS TMR0SE PSA PS<2:0> 165
TMR0 Holding Register for the 8-bit Timer0 Count 163*
TRISA — — TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
Legend: — = Unimplemented location, read as ‘0’. Shaded cells are not used by the Timer0 module.
* Page provides register information.
Note 1: Unimplemented, read as ‘1’.
000
001
010
011
100
101
110
111
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
1 : 256
Bit Value Timer0 Rate
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NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 167
PIC16(L)F1508/9
19.0 TIMER1 MODULE WITH GATE
CONTROL
The Timer1 module is a 16-bit timer/counter with the
following features:
• 16-bit timer/counter register pair (TMR1H:TMR1L)
• Programmable internal or external clock source
• 2-bit prescaler
• Optionally synchronized comparator out
• Multiple Timer1 gate (count enable) sources
• Interrupt on overflow
• Wake-up on overflow (external clock,
Asynchronous mode only)
• Special Event Trigger
• Selectable Gate Source Polarity
• Gate Toggle mode
• Gate Single-Pulse mode
• Gate Value Status
• Gate Event Interrupt
Figure 19-1 is a block diagram of the Timer1 module.
FIGURE 19-1: TIMER1 BLOCK DIAGRAM
TMR1H TMR1L
T1SYNC
T1CKPS<1:0>
Prescaler
1, 2, 4, 8
0
1
Synchronized
Clock Input
2
Set flag bit
TMR1IF on
Overflow TMR1(2)
TMR1ON
Note 1: ST Buffer is high speed type when using T1CKI.
2: Timer1 register increments on rising edge.
3: Synchronize does not operate while in Sleep.
T1G
FOSC/4
Internal
Clock
TMR1CS<1:0>
Synchronize(3)
det
Sleep input
TMR1GE
0
1
00
01
T1GPOL
D
Q
CK
Q
0
1
T1GVAL
T1GTM
Single Pulse
Acq. Control
T1GSPM
T1GGO/DONE
T1GSS<1:0>
10
11
00
01
FOSC
Internal
Clock
LFINTOSC
R
D
EN
Q
Q1
RD
T1GCON
Data Bus
det
Interrupt
TMR1GIF
Set
T1CLK
FOSC/2
Internal
Clock
D
EN
Q
t1g_in
TMR1ON
From Timer0
Overflow
To ADC Auto-Conversion
10
11
SYNCC1OUT
SYNCC2OUT
To Clock Switching
Modules
Secondary
SOSCO/T1CKI
SOSCI
T1OSCEN
1
0
(1)
EN
OUT
Oscillator
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DS41609A-page 168 Preliminary 2011 Microchip Technology Inc.
19.1 Timer1 Operation
The Timer1 module is a 16-bit incrementing counter
which is accessed through the TMR1H:TMR1L register
pair. Writes to TMR1H or TMR1L directly update the
counter.
When used with an internal clock source, the module is
a timer and increments on every instruction cycle.
When used with an external clock source, the module
can be used as either a timer or counter and incre-
ments on every selected edge of the external source.
Timer1 is enabled by configuring the TMR1ON and
TMR1GE bits in the T1CON and T1GCON registers,
respectively. Table 19-1 displays the Timer1 enable
selections.
19.2 Clock Source Selection
The TMR1CS<1:0> bits of the T1CON register are used
to select the clock source for Timer1. Table 19- 2
displays the clock source selections.
19.2.1 INTERNAL CLOCK SOURCE
When the internal clock source is selected the
TMR1H:TMR1L register pair will increment on multiples
of FOSC as determined by the Timer1 prescaler.
When the FOSC internal clock source is selected, the
Timer1 register value will increment by four counts every
instruction clock cycle. Due to this condition, a 2 LSB
error in resolution will occur when reading the Timer1
value. To utilize the full resolution of Timer1, an
asynchronous input signal must be used to gate the
Timer1 clock input.
The following asynchronous sources may be used:
• Asynchronous event on the T1G pin to Timer1
gate
19.2.2 EXTERNAL CLOCK SOURCE
When the external clock source is selected, the Timer1
module may work as a timer or a counter.
When enabled to count, Timer1 is incremented on the
rising edge of the external clock input T1CKI. The
external clock source can be synchronized to the
microcontroller system clock or it can run
asynchronously.
TABLE 19-1: TIMER1 ENABLE
SELECTIONS
TMR1ON TMR1GE Timer1
Operation
00Off
01Off
10Always On
11Count Enabled
Note: In Counter mode, a falling edge must be
registered by the counter prior to the first
incrementing rising edge after any one or
more of the following conditions:
• Timer1 enabled after POR
• Write to TMR1H or TMR1L
• Timer1 is disabled
• Timer1 is disabled (TMR1ON = 0)
when T1CKI is high then Timer1 is
enabled (TMR1ON=1) when T1CKI is
low.
TABLE 19-2: CLOCK SOURCE SELECTIONS
TMR1CS<1:0> T1OSCEN Clock Source
11 x LFINTOSC
10 1Secondary Oscillator Circuit on SOSCI/SOSCO Pins
0External Clocking on T1CKI Pin
01 x System Clock (FOSC) or Oscillator. Circuit on SOSCI/SOSCO
00 x Instruction Clock (FOSC/4)
2011 Microchip Technology Inc. Preliminary DS41609A-page 169
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19.3 Timer1 Prescaler
Timer1 has four prescaler options allowing 1, 2, 4 or 8
divisions of the clock input. The T1CKPS bits of the
T1CON register control the prescale counter. The
prescale counter is not directly readable or writable;
however, the prescaler counter is cleared upon a write to
TMR1H or TMR1L.
19.4 Timer1 Operation in
Asynchronous Counter Mode
If control bit T1SYNC of the T1CON register is set, the
external clock input is not synchronized. The timer
increments asynchronously to the internal phase
clocks. If the external clock source is selected then the
timer will continue to run during Sleep and can
generate an interrupt on overflow, which will wake-up
the processor. However, special precautions in
software are needed to read/write the timer (see
Section 19.4.1 “Reading and Writing Timer1 in
Asynchronous Counter Mode”).
19.4.1 READING AND WRITING TIMER1 IN
ASYNCHRONOUS COUNTER
MODE
Reading TMR1H or TMR1L while the timer is running
from an external asynchronous clock will ensure a valid
read (taken care of in hardware). However, the user
should keep in mind that reading the 16-bit timer in two
8-bit values itself, poses certain problems, since the
timer may overflow between the reads.
For writes, it is recommended that the user simply stop
the timer and write the desired values. A write
contention may occur by writing to the timer registers,
while the register is incrementing. This may produce an
unpredictable value in the TMR1H:TMR1L register pair.
19.5 Timer1 Gate
Timer1 can be configured to count freely or the count
can be enabled and disabled using Timer1 gate
circuitry. This is also referred to as Timer1 Gate Enable.
Timer1 gate can also be driven by multiple selectable
sources.
19.5.1 TIMER1 GATE ENABLE
The Timer1 Gate Enable mode is enabled by setting
the TMR1GE bit of the T1GCON register. The polarity
of the Timer1 Gate Enable mode is configured using
the T1GPOL bit of the T1GCON register.
When Timer1 Gate Enable mode is enabled, Timer1
will increment on the rising edge of the Timer1 clock
source. When Timer1 Gate Enable mode is disabled,
no incrementing will occur and Timer1 will hold the
current count. See Figure 19-3 for timing details.
19.5.2 TIMER1 GATE SOURCE
SELECTION
Timer1 gate source selections are shown in Table 19-4.
Source selection is controlled by the T1GSS<1:0> bits
of the T1GCON register. The polarity for each available
source is also selectable. Polarity selection is controlled
by the T1GPOL bit of the T1GCON register.
TABLE 19-4: TIMER1 GATE SOURCES
Note: When switching from synchronous to
asynchronous operation, it is possible to
skip an increment. When switching from
asynchronous to synchronous operation,
it is possible to produce an additional
increment.
TABLE 19-3: TIMER1 GATE ENABLE
SELECTIONS
T1CLK T1GPOL T1G Timer1 Operation
00Counts
01Holds Count
10Holds Count
11Counts
T1GSS Timer1 Gate Source
00 Timer1 Gate Pin
01 Overflow of Timer0
(TMR0 increments from FFh to 00h)
10 Comparator 1 Output SYNCC1OUT
(optionally synchronized comparator output)
11 Comparator 2 Output SYNCC2OUT
(optionally synchronized comparator output)
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DS41609A-page 170 Preliminary 2011 Microchip Technology Inc.
19.5.2.1 T1G Pin Gate Operation
The T1G pin is one source for Timer1 Gate Control. It
can be used to supply an external source to the Timer1
gate circuitry.
19.5.2.2 Timer0 Overflow Gate Operation
When Timer0 increments from FFh to 00h, a low-to-
high pulse will automatically be generated and inter-
nally supplied to the Timer1 gate circuitry.
19.5.3 TIMER1 GATE TOGGLE MODE
When Timer1 Gate Toggle mode is enabled, it is possi-
ble to measure the full-cycle length of a Timer1 gate
signal, as opposed to the duration of a single level
pulse.
The Timer1 gate source is routed through a flip-flop that
changes state on every incrementing edge of the sig-
nal. See Figure 19-4 for timing details.
Timer1 Gate Toggle mode is enabled by setting the
T1GTM bit of the T1GCON register. When the T1GTM
bit is cleared, the flip-flop is cleared and held clear. This
is necessary in order to control which edge is
measured.
19.5.4 TIMER1 GATE SINGLE-PULSE
MODE
When Timer1 Gate Single-Pulse mode is enabled, it is
possible to capture a single pulse gate event. Timer1
Gate Single-Pulse mode is first enabled by setting the
T1GSPM bit in the T1GCON register. Next, the T1GGO/
DONE bit in the T1GCON register must be set. The
Timer1 will be fully enabled on the next incrementing
edge. On the next trailing edge of the pulse, the T1GGO/
DONE bit will automatically be cleared. No other gate
events will be allowed to increment Timer1 until the
T1GGO/DONE bit is once again set in software. See
Figure 19-5 for timing details.
If the Single Pulse Gate mode is disabled by clearing the
T1GSPM bit in the T1GCON register, the T1GGO/DONE
bit should also be cleared.
Enabling the Toggle mode and the Single-Pulse mode
simultaneously will permit both sections to work
together. This allows the cycle times on the Timer1 gate
source to be measured. See Figure 19-6 for timing
details.
19.5.5 TIMER1 GATE VALUE STATUS
When Timer1 Gate Value Status is utilized, it is possible
to read the most current level of the gate control value.
The value is stored in the T1GVAL bit in the T1GCON
register. The T1GVAL bit is valid even when the Timer1
gate is not enabled (TMR1GE bit is cleared).
19.5.6 TIMER1 GATE EVENT INTERRUPT
When Timer1 Gate Event Interrupt is enabled, it is pos-
sible to generate an interrupt upon the completion of a
gate event. When the falling edge of T1GVAL occurs,
the TMR1GIF flag bit in the PIR1 register will be set. If
the TMR1GIE bit in the PIE1 register is set, then an
interrupt will be recognized.
The TMR1GIF flag bit operates even when the Timer1
gate is not enabled (TMR1GE bit is cleared).
Note: Enabling Toggle mode at the same time
as changing the gate polarity may result in
indeterminate operation.
2011 Microchip Technology Inc. Preliminary DS41609A-page 171
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19.6 Timer1 Interrupt
The Timer1 register pair (TMR1H:TMR1L) increments
to FFFFh and rolls over to 0000h. When Timer1 rolls
over, the Timer1 interrupt flag bit of the PIR1 register is
set. To enable the interrupt on rollover, you must set
these bits:
• TMR1ON bit of the T1CON register
• TMR1IE bit of the PIE1 register
• PEIE bit of the INTCON register
• GIE bit of the INTCON register
The interrupt is cleared by clearing the TMR1IF bit in
the Interrupt Service Routine.
19.7 Timer1 Operation During Sleep
Timer1 can only operate during Sleep when setup in
Asynchronous Counter mode. In this mode, an external
crystal or clock source can be used to increment the
counter. To set up the timer to wake the device:
• TMR1ON bit of the T1CON register must be set
• TMR1IE bit of the PIE1 register must be set
• PEIE bit of the INTCON register must be set
• T1SYNC bit of the T1CON register must be set
• TMR1CS bits of the T1CON register must be
configured
The device will wake-up on an overflow and execute
the next instructions. If the GIE bit of the INTCON
register is set, the device will call the Interrupt Service
Routine.
Timer1 oscillator will continue to operate in Sleep
regardless of the T1SYNC bit setting.
19.7.1 ALTERNATE PIN LOCATIONS
This module incorporates I/O pins that can be moved to
other locations with the use of the alternate pin function
register, APFCON. To determine which pins can be
moved and what their default locations are upon a
Reset, see Section 11.1 “Alternate Pin Function” for
more information.
FIGURE 19-2: TIMER1 INCREMENTING EDGE
Note: The TMR1H:TMR1L register pair and the
TMR1IF bit should be cleared before
enabling interrupts.
T1CKI = 1
when TMR1
Enabled
T1CKI = 0
when TMR1
Enabled
Note 1: Arrows indicate counter increments.
2: In Counter mode, a falling edge must be registered by the counter prior to the first incrementing rising edge of the clock.
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DS41609A-page 172 Preliminary 2011 Microchip Technology Inc.
FIGURE 19-3: TIMER1 GATE ENABLE MODE
FIGURE 19-4: TIMER1 GATE TOGGLE MODE
TMR1GE
T1GPOL
t1g_in
T1CKI
T1GVAL
Timer1 N N + 1 N + 2 N + 3 N + 4
TMR1GE
T1GPOL
T1GTM
t1g_in
T1CKI
T1GVAL
Timer1 N N + 1 N + 2 N + 3 N + 4 N + 5 N + 6 N + 7 N + 8
2011 Microchip Technology Inc. Preliminary DS41609A-page 173
PIC16(L)F1508/9
FIGURE 19-5: TIMER1 GATE SINGLE-PULSE MODE
TMR1GE
T1GPOL
t1g_in
T1CKI
T1GVAL
Timer1 N N + 1 N + 2
T1GSPM
T1GGO/
DONE
Set by software
Cleared by hardware on
falling edge of T1GVAL
Set by hardware on
falling edge of T1GVAL
Cleared by software
Cleared by
software
TMR1GIF
Counting enabled on
rising edge of T1G
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DS41609A-page 174 Preliminary 2011 Microchip Technology Inc.
FIGURE 19-6: TIMER1 GATE SINGLE-PULSE AND TOGGLE COMBINED MODE
TMR1GE
T1GPOL
t1g_in
T1CKI
T1GVAL
Timer1 NN + 1
N + 2
T1GSPM
T1GGO/
DONE
Set by software
Cleared by hardware on
falling edge of T1GVAL
Set by hardware on
falling edge of T1GVAL
Cleared by software
Cleared by
software
TMR1GIF
T1GTM
Counting enabled on
rising edge of T1G
N + 4
N + 3
2011 Microchip Technology Inc. Preliminary DS41609A-page 175
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19.8 Timer1 Control Registers
REGISTER 19-1: T1CON: TIMER1 CONTROL REGISTER
R/W-0/u R/W-0/u R/W-0/u R/W-0/u R/W-0/u R/W-0/u U-0 R/W-0/u
TMR1CS<1:0> T1CKPS<1:0> T1OSCEN T1SYNC —TMR1ON
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 TMR1CS<1:0>: Timer1 Clock Source Select bits
11 = Timer1 clock source is Capacitive Sensing Oscillator (CAPOSC)
10 = Timer1 clock source is pin or oscillator:
If T1OSCEN = 0:
External clock from T1CKI pin (on the rising edge)
If T1OSCEN = 1:
Crystal oscillator on SOSCI/SOSCO pins
01 = Timer1 clock source is system clock (FOSC)
00 = Timer1 clock source is instruction clock (FOSC/4)
bit 5-4 T1CKPS<1:0>: 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: LP Oscillator Enable Control bit
1 = Dedicated Timer1 oscillator circuit enabled
0 = Dedicated Timer1 oscillator circuit disabled
bit 2 T1SYNC: Timer1 Synchronization Control bit
1 = Do not synchronize asynchronous clock input
0 = Synchronize asynchronous clock input with system clock (FOSC)
bit 1 Unimplemented: Read as ‘0’
bit 0 TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1 and clears Timer1 gate flip-flop
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DS41609A-page 176 Preliminary 2011 Microchip Technology Inc.
REGISTER 19-2: T1GCON: TIMER1 GATE CONTROL REGISTER
R/W-0/u R/W-0/u R/W-0/u R/W-0/u R/W/HC-0/u R-x/x R/W-0/u R/W-0/u
TMR1GE T1GPOL T1GTM T1GSPM T1GGO/
DONE
T1GVAL T1GSS<1:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared HC = Bit is cleared by hardware
bit 7 TMR1GE: Timer1 Gate Enable bit
If TMR1ON = 0:
This bit is ignored
If TMR1ON = 1:
1 = Timer1 counting is controlled by the Timer1 gate function
0 = Timer1 counts regardless of Timer1 gate function
bit 6 T1GPOL: Timer1 Gate Polarity bit
1 = Timer1 gate is active-high (Timer1 counts when gate is high)
0 = Timer1 gate is active-low (Timer1 counts when gate is low)
bit 5 T1GTM: Timer1 Gate Toggle Mode bit
1 = Timer1 Gate Toggle mode is enabled
0 = Timer1 Gate Toggle mode is disabled and toggle flip-flop is cleared
Timer1 gate flip-flop toggles on every rising edge.
bit 4 T1GSPM: Timer1 Gate Single-Pulse Mode bit
1 = Timer1 gate Single-Pulse mode is enabled and is controlling Timer1 gate
0 = Timer1 gate Single-Pulse mode is disabled
bit 3 T1GGO/DONE: Timer1 Gate Single-Pulse Acquisition Status bit
1 = Timer1 gate single-pulse acquisition is ready, waiting for an edge
0 = Timer1 gate single-pulse acquisition has completed or has not been started
bit 2 T1GVAL: Timer1 Gate Current State bit
Indicates the current state of the Timer1 gate that could be provided to TMR1H:TMR1L.
Unaffected by Timer1 Gate Enable (TMR1GE).
bit 0 T1GSS<1:0>: Timer1 Gate Source Select bits
11 = Comparator 2 optionally synchronized output (SYNCC2OUT)
10 = Comparator 1 optionally synchronized output (SYNCC1OUT)
01 = Timer0 overflow output
00 = Timer1 gate pin
2011 Microchip Technology Inc. Preliminary DS41609A-page 177
PIC16(L)F1508/9
TABLE 19-5: SUMMARY OF REGISTERS ASSOCIATED WITH TIMER1
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
ANSELA — — —ANSA4 —ANSA2 ANSA1 ANSA0 115
APFCON — — — SSSEL T1GSEL —CLC1SEL NCO1SEL 112
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IE TMR1IE 79
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Count 171*
TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Count 171*
TRISA —— TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
T1CON TMR1CS<1:0> T1CKPS<1:0> T1OSCEN T1SYNC —TMR1ON175
T1GCON TMR1GE T1GPOL T1GTM T1GSPM T1GGO/
DONE
T1GVAL T1GSS<1:0> 176
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by the Timer1 module.
* Page provides register information.
Note 1: Unimplemented, read as ‘1’.
PIC16(L)F1508/9
DS41609A-page 178 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 179
PIC16(L)F1508/9
20.0 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, 1:16,
and 1:64)
• Software programmable postscaler (1:1 to 1:16)
• Interrupt on TMR2 match with PR2, respectively
See Figure 20-1 for a block diagram of Timer2.
FIGURE 20-1: TIMER2 BLOCK DIAGRAM
Comparator
TMR2 Sets Flag
TMR2
Output
Reset
Postscaler
Prescaler
PR2
2
FOSC/4
1:1 to 1:16
1:1, 1:4, 1:16, 1:64
EQ
4
bit TMR2IF
T2OUTPS<3:0>
T2CKPS<1:0>
PIC16(L)F1508/9
DS41609A-page 180 Preliminary 2011 Microchip Technology Inc.
20.1 Timer2 Operation
The clock input to the Timer2 module is the system
instruction clock (FOSC/4).
TMR2 increments from 00h on each clock edge.
A 4-bit counter/prescaler on the clock input allows direct
input, divide-by-4 and divide-by-16 prescale options.
These options are selected by the prescaler control bits,
T2CKPS<1:0> of the T2CON register. 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 20.2 “Timer2 Interrupt”).
The TMR2 and PR2 registers are both directly readable
and writable. The TMR2 register is cleared on any
device Reset, whereas the PR2 register initializes to
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
• Power-on Reset (POR)
• Brown-out Reset (BOR)
•MCLR
Reset
• Watchdog Timer (WDT) Reset
• Stack Overflow Reset
• Stack Underflow Reset
•RESET Instruction
20.2 Timer2 Interrupt
Timer2 can also generate an optional device interrupt.
The Timer2 output signal (TMR2-to-PR2 match)
provides the input for the 4-bit counter/postscaler. This
counter generates the TMR2 match interrupt flag which
is latched in TMR2IF of the PIR1 register. The interrupt
is enabled by setting the TMR2 Match Interrupt Enable
bit, TMR2IE of the PIE1 register.
A range of 16 postscale options (from 1:1 through 1:16
inclusive) can be selected with the postscaler control
bits, T2OUTPS<3:0>, of the T2CON register.
20.3 Timer2 Output
The unscaled output of TMR2 is available primarily to
the PWMx module, where it is used as a time base for
operation.
20.4 Timer2 Operation During Sleep
Timer2 cannot be operated while the processor is in
Sleep mode. The contents of the TMR2 and PR2
registers will remain unchanged while the processor is
in Sleep mode.
Note: TMR2 is not cleared when T2CON is
written.
2011 Microchip Technology Inc. Preliminary DS41609A-page 181
PIC16(L)F1508/9
REGISTER 20-1: T2CON: TIMER2 CONTROL REGISTER
U-0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
— T2OUTPS<3:0> TMR2ON T2CKPS<1:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 Unimplemented: Read as ‘0’
bit 6-3 T2OUTPS<3:0>: Timer2 Output Postscaler Select bits
0000 = 1:1 Postscaler
0001 = 1:2 Postscaler
0010 = 1:3 Postscaler
0011 = 1:4 Postscaler
0100 = 1:5 Postscaler
0101 = 1:6 Postscaler
0110 = 1:7 Postscaler
0111 = 1:8 Postscaler
1000 = 1:9 Postscaler
1001 = 1:10 Postscaler
1010 = 1:11 Postscaler
1011 = 1:12 Postscaler
1100 = 1:13 Postscaler
1101 = 1:14 Postscaler
1110 = 1:15 Postscaler
1111 = 1:16 Postscaler
bit 2 TMR2ON: Timer2 On bit
1 = Timer2 is on
0 = Timer2 is off
bit 1-0 T2CKPS<1:0>: Timer2 Clock Prescale Select bits
00 = Prescaler is 1
01 = Prescaler is 4
10 = Prescaler is 16
11 = Prescaler is 64
PIC16(L)F1508/9
DS41609A-page 182 Preliminary 2011 Microchip Technology Inc.
TABLE 20-1: SUMMARY OF REGISTERS ASSOCIATED WITH TIMER2
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IETMR1IE 79
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
PR2 Timer2 Module Period Register 179*
PWM1CON PWM1EN PWM1OE PWM1OUT PWM1POL — — — — 269
PWM2CON PWM2EN PWM2OE PWM2OUT PWM2POL — — — — 269
PWM3CON PWM3EN PWM3OE PWM3OUT PWM3POL — — — — 269
PWM4CON PWM4EN PWM4OE PWM4OUT PWM4POL — — — — 269
T2CON — T2OUTPS<3:0> TMR2ON T2CKPS<1:0> 181
TMR2 Holding Register for the 8-bit TMR2 Count 179*
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used for Timer2 module.
* Page provides register information.
2011 Microchip Technology Inc. Preliminary DS41609A-page 183
PIC16(L)F1508/9
21.0 MASTER SYNCHRONOUS
SERIAL PORT MODULE
21.1 Master SSP (MSSP) Module
Overview
The Master Synchronous Serial Port (MSSPx) module
is a serial interface useful for communicating with other
peripheral or microcontroller devices. These peripheral
devices may be serial EEPROMs, shift registers, dis-
play drivers, A/D converters, etc. The MSSPx module
can operate in one of two modes:
• Serial Peripheral Interface (SPI)
• Inter-Integrated Circuit (I2C™)
The SPI interface supports the following modes and
features:
•Master mode
• Slave mode
• Clock Parity
• Slave Select Synchronization (Slave mode only)
• Daisy-chain connection of slave devices
Figure 21-1 is a block diagram of the SPI interface
module.
FIGURE 21-1: MSSPX BLOCK DIAGRAM (SPI MODE)
( )
Read Write
Data Bus
SSPSR Reg
SSPM<3:0>
bit 0 Shift
Clock
SSx Control
Enable
Edge
Select
Clock Select
TMR2 Output
TOSC
Prescaler
4, 16, 64
2
Edge
Select
2 (CKP, CKE)
4
TRIS bit
SDO
SSPBUF Reg
SDI
SS
SCK
Baud Rate
Generator
(SSPxADD)
PIC16(L)F1508/9
DS41609A-page 184 Preliminary 2011 Microchip Technology Inc.
The I2C interface supports the following modes and
features:
•Master mode
• Slave mode
• Byte NACKing (Slave mode)
• Limited Multi-master support
• 7-bit and 10-bit addressing
• Start and Stop interrupts
• Interrupt masking
• Clock stretching
• Bus collision detection
• General call address matching
•Address masking
• Address Hold and Data Hold modes
• Selectable SDAx hold times
Figure 21-2 is a block diagram of the I2C interface mod-
ule in Master mode. Figure 21-3 is a diagram of the I2C
interface module in Slave mode.
The PIC16F1508/9 has one MSSP module.
FIGURE 21-2: MSSPX BLOCK DIAGRAM (I2C™ MASTER MODE)
Note 1: In devices with more than one MSSP
module, it is very important to pay close
attention to SSPxCONx register names.
SSPxCON1 and SSPxCON2 registers
control different operational aspects of
the same module, while SSPxCON1 and
SSP2CON1 control the same features for
two different modules.
2: Throughout this section, generic refer-
ences to an MSSPx module in any of its
operating modes may be interpreted as
being equally applicable to MSSPx or
MSSP2. Register names, module I/O sig-
nals, and bit names may use the generic
designator ‘x’ to indicate the use of a
numeral to distinguish a particular module
when required.
Read Write
SSPxSR
Start bit, Stop bit,
Start bit detect,
SSPxBUF
Internal
data bus
Set/Reset: S, P, SSPxSTAT, WCOL, SSPOV
Shift
Clock
MSb LSb
SDAx
Acknowledge
Generate (SSPxCON2)
Stop bit detect
Write collision detect
Clock arbitration
State counter for
end of XMIT/RCV
SCLx
SCLx in
Bus Collision
SDAx in
Receive Enable (RCEN)
Clock Cntl
Clock arbitrate/BCOL detect
(Hold off clock source)
[SSPM<3:0>]
Baud Rate
Reset SEN, PEN (SSPxCON2)
Generator
(SSPxADD)
Address Match detect
Set SSPxIF, BCLxIF
2011 Microchip Technology Inc. Preliminary DS41609A-page 185
PIC16(L)F1508/9
FIGURE 21-3: MSSP BLOCK DIAGRAM (I2C™ SLAVE MODE)
Read Write
SSPxSR Reg
Match Detect
SSPxADD Reg
Start and
Stop bit Detect
SSPxBUF Reg
Internal
Data Bus
Addr Match
Set, Reset
S, P bits
(SSPxSTAT Reg)
SCLx
SDAx
Shift
Clock
MSb LSb
SSPxMSK Reg
PIC16(L)F1508/9
DS41609A-page 186 Preliminary 2011 Microchip Technology Inc.
21.2 SPI Mode Overview
The Serial Peripheral Interface (SPI) bus is a
synchronous serial data communication bus that
operates in Full-Duplex mode. Devices communicate
in a master/slave environment where the master device
initiates the communication. A slave device is
controlled through a Chip Select known as Slave
Select.
The SPI bus specifies four signal connections:
• Serial Clock (SCKx)
• Serial Data Out (SDOx)
• Serial Data In (SDIx)
• Slave Select (SSx)
Figure 21-1 shows the block diagram of the MSSP
module when operating in SPI mode.
The SPI bus operates with a single master device and
one or more slave devices. When multiple slave
devices are used, an independent Slave Select con-
nection is required from the master device to each
slave device.
Figure 21-4 shows a typical connection between a
master device and multiple slave devices.
The master selects only one slave at a time. Most slave
devices have tri-state outputs so their output signal
appears disconnected from the bus when they are not
selected.
Transmissions involve two shift registers, eight bits in
size, one in the master and one in the slave. With either
the master or the slave device, data is always shifted
out one bit at a time, with the Most Significant bit (MSb)
shifted out first. At the same time, a new Least
Significant bit (LSb) is shifted into the same register.
Figure 21-5 shows a typical connection between two
processors configured as master and slave devices.
Data is shifted out of both shift registers on the pro-
grammed clock edge and latched on the opposite edge
of the clock.
The master device transmits information out on its
SDOx output pin which is connected to, and received
by, the slave’s SDIx input pin. The slave device trans-
mits information out on its SDOx output pin, which is
connected to, and received by, the master’s SDIx input
pin.
To begin communication, the master device first sends
out the clock signal. Both the master and the slave
devices should be configured for the same clock polar-
ity.
The master device starts a transmission by sending out
the MSb from its shift register. The slave device reads
this bit from that same line and saves it into the LSb
position of its shift register.
During each SPI clock cycle, a full-duplex data
transmission occurs. This means that while the master
device is sending out the MSb from its shift register (on
its SDOx pin) and the slave device is reading this bit
and saving it as the LSb of its shift register, that the
slave device is also sending out the MSb from its shift
register (on its SDOx pin) and the master device is
reading this bit and saving it as the LSb of its shift
register.
After 8 bits have been shifted out, the master and slave
have exchanged register values.
If there is more data to exchange, the shift registers are
loaded with new data and the process repeats itself.
Whether the data is meaningful or not (dummy data),
depends on the application software. This leads to
three scenarios for data transmission:
• Master sends useful data and slave sends dummy
data.
• Master sends useful data and slave sends useful
data.
• Master sends dummy data and slave sends useful
data.
Transmissions may involve any number of clock
cycles. When there is no more data to be transmitted,
the master stops sending the clock signal and it dese-
lects the slave.
Every slave device connected to the bus that has not
been selected through its slave select line must disre-
gard the clock and transmission signals and must not
transmit out any data of its own.
2011 Microchip Technology Inc. Preliminary DS41609A-page 187
PIC16(L)F1508/9
FIGURE 21-4: SPI MASTER AND MULTIPLE SLAVE CONNECTION
21.2.1 SPI MODE REGISTERS
The MSSP module has five registers for SPI mode
operation. These are:
• MSSP STATUS register (SSPxSTAT)
• MSSP Control Register 1 (SSPxCON1)
• MSSP Control Register 3 (SSPxCON3)
• MSSP Data Buffer register (SSPxBUF)
• MSSP Address register (SSPxADD)
• MSSP 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.
In SPI master mode, SSPxADD can be loaded with a
value used in the Baud Rate Generator. More informa-
tion on the Baud Rate Generator is available in
Section 21.7 “Baud Rate Generator”.
SSPxSR is the shift register used for shifting data in
and out. SSPxBUF provides indirect access to the
SSPxSR register. SSPxBUF is the buffer register to
which data bytes are written, and from which data
bytes are read.
In receive operations, SSPxSR and SSPxBUF
together create a 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 buffered. A
write to SSPxBUF will write to both SSPxBUF and
SSPxSR.
SPI Master SCKx
SDOx
SDIx
General I/O
General I/O
General I/O
SCKx
SDIx
SDOx
SSx
SPI Slave
#1
SCKx
SDIx
SDOx
SSx
SPI Slave
#2
SCKx
SDIx
SDOx
SSx
SPI Slave
#3
PIC16(L)F1508/9
DS41609A-page 188 Preliminary 2011 Microchip Technology Inc.
21.2.2 SPI MODE 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)
To enable the serial port, SSP Enable bit, SSPEN of the
SSPxCON1 register, must be set. To reset or reconfig-
ure SPI mode, clear the SSPEN bit, re-initialize the
SSPxCONx registers and then set the SSPEN bit. This
configures the SDI, SDO, SCK and SS pins as serial
port pins. For the pins to behave as the serial port func-
tion, some must have their data direction bits (in the
TRIS register) appropriately programmed as follows:
• SDIx must have corresponding TRIS bit set
• SDOx must have corresponding TRIS bit cleared
• SCKx (Master mode) must have corresponding
TRIS bit cleared
• SCKx (Slave mode) must have corresponding
TRIS bit set
• SSx must have corresponding TRIS 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.
The MSSP 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 of the SSPxSTAT register, 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
transmission/reception of data will be ignored and the
write collision detect bit, WCOL of the SSPxCON1
register, will be set. User software must clear the
WCOL bit to allow the following write(s) to the
SSPxBUF register to complete 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 of the SSPxSTAT register,
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.
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.
FIGURE 21-5: SPI MASTER/SLAVE CONNECTION
Serial Input Buffer
(BUF)
Shift Register
(SSPxSR)
MSb LSb
SDOx
SDIx
Processor 1
SCKx
SPI Master SSPM<3:0> = 00xx
Serial Input Buffer
(SSPxBUF)
Shift Register
(SSPxSR)
LSb
MSb
SDIx
SDOx
Processor 2
SCKx
SPI Slave SSPM<3:0> = 010x
Serial Clock
SSx
Slave Select
General I/O (optional)
= 1010
2011 Microchip Technology Inc. Preliminary DS41609A-page 189
PIC16(L)F1508/9
21.2.3 SPI MASTER MODE
The master can initiate the data transfer at any time
because it controls the SCKx line. The master
determines when the slave (Processor 2, Figure 21-5)
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).
The clock polarity is selected by appropriately
programming the CKP bit of the SSPxCON1 register
and the CKE bit of the SSPxSTAT register. This then,
would give waveforms for SPI communication as
shown in Figure 21-6, Figure 21-9 and Figure 21-10,
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)
•F
OSC/16 (or 4 * TCY)
•F
OSC/64 (or 16 * TCY)
• Timer2 output/2
• Fosc/(4 * (SSPxADD + 1))
Figure 21-6 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 21-6: 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)
bit 0
PIC16(L)F1508/9
DS41609A-page 190 Preliminary 2011 Microchip Technology Inc.
21.2.4 SPI SLAVE MODE
In Slave mode, the data is transmitted and received as
external clock pulses appear on SCKx. When the last
bit is latched, the SSPxIF interrupt flag bit is set.
Before enabling the module in SPI Slave mode, the clock
line must match the proper Idle state. The clock line can
be observed by reading the SCKx pin. The Idle state is
determined by the CKP bit of the SSPxCON1 register.
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. The shift register is clocked from the SCKx pin
input and when a byte is received, the device will gen-
erate an interrupt. If enabled, the device will wake-up
from Sleep.
21.2.4.1 Daisy-Chain Configuration
The SPI bus can sometimes be connected in a
daisy-chain configuration. The first slave output is con-
nected to the second slave input, the second slave
output is connected to the third slave input, and so on.
The final slave output is connected to the master input.
Each slave sends out, during a second group of clock
pulses, an exact copy of what was received during the
first group of clock pulses. The whole chain acts as
one large communication shift register. The
daisy-chain feature only requires a single Slave Select
line from the master device.
Figure 21-7 shows the block diagram of a typical
daisy-chain connection when operating in SPI mode.
In a daisy-chain configuration, only the most recent
byte on the bus is required by the slave. Setting the
BOEN bit of the SSPxCON3 register will enable writes
to the SSPxBUF register, even if the previous byte has
not been read. This allows the software to ignore data
that may not apply to it.
21.2.5 SLAVE SELECT
SYNCHRONIZATION
The Slave Select can also be used to synchronize com-
munication. The Slave Select line is held high until the
master device is ready to communicate. When the
Slave Select line is pulled low, the slave knows that a
new transmission is starting.
If the slave fails to receive the communication properly,
it will be reset at the end of the transmission, when the
Slave Select line returns to a high state. The slave is
then ready to receive a new transmission when the
Slave Select line is pulled low again. If the Slave Select
line is not used, there is a risk that the slave will even-
tually become out of sync with the master. If the slave
misses a bit, it will always be one bit off in future trans-
missions. Use of the Slave Select line allows the slave
and master to align themselves at the beginning of
each transmission.
The SSx pin allows a Synchronous Slave mode. The
SPI must be in Slave mode with SSx pin control
enabled (SSPxCON1<3:0> = 0100).
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. External pull-up/pull-down
resistors may be desirable depending on the applica-
tion.
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.
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: When the SPI is used in Slave mode with
CKE set; the user must enable SSx pin
control.
3: While operated in SPI Slave mode the
SMP bit of the SSPxSTAT register must
remain clear.
2011 Microchip Technology Inc. Preliminary DS41609A-page 191
PIC16(L)F1508/9
FIGURE 21-7: SPI DAISY-CHAIN CONNECTION
FIGURE 21-8: SLAVE SELECT SYNCHRONOUS WAVEFORM
SPI Master SCK
SDOx
SDIx
General I/O
SCK
SDIx
SDOx
SSx
SPI Slave
#1
SCK
SDIx
SDOx
SSx
SPI Slave
#2
SCK
SDIx
SDOx
SSx
SPI Slave
#3
SCKx
(CKP = 1
SCKx
(CKP = 0
Input
Sample
SDIx
bit 7
SDOx bit 7 bit 6 bit 7
SSPxIF
Interrupt
CKE = 0)
CKE = 0)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SSx
Flag
bit 0
bit 7
bit 0
bit 6
SSPxBUF to
SSPxSR
Shift register SSPxSR
and bit count are reset
PIC16(L)F1508/9
DS41609A-page 192 Preliminary 2011 Microchip Technology Inc.
FIGURE 21-9: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)
FIGURE 21-10: 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
CKE = 0)
CKE = 0)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SSx
Flag
Optional
bit 0
detection active
Write Collision
Valid
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
CKE = 1)
CKE = 1)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SSx
Flag
Not Optional
Write Collision
detection active
Valid
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PIC16(L)F1508/9
21.2.6 SPI OPERATION IN SLEEP MODE
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.
Special care must be taken by the user when the MSSP
clock is much faster than the system clock.
In Slave mode, when MSSP interrupts are enabled,
after the master completes sending data, an MSSP
interrupt will wake the controller from Sleep.
If an exit from Sleep mode is not desired, MSSP inter-
rupts should be disabled.
In SPI Master mode, when the Sleep mode is selected,
all module clocks are halted and the transmis-
sion/reception will remain in that state until the device
wakes. After the device returns to Run mode, the mod-
ule 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 Sleep mode and data
to be shifted into the SPI Transmit/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.
TABLE 21-1: SUMMARY OF REGISTERS ASSOCIATED WITH SPI OPERATION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
ANSELA — — — ANSA4 —ANSA2 ANSA1 ANSA0 115
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IE TMR1IE 79
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
SSP1BUF Synchronous Serial Port Receive Buffer/Transmit Register 187*
SSP1CON1 WCOL SSPOV SSPEN CKP SSPM<3:0> 232
SSP1CON3 ACKTIM PCIE SCIE BOEN SDAHT SBCDE AHEN DHEN 234
SSP1STAT SMP CKE D/A P S R/W UA BF 231
TRISA — — TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
Legend: — = Unimplemented location, read as ‘0’. Shaded cells are not used by the MSSP in SPI mode.
* Page provides register information.
Note 1: Unimplemented, read as ‘1’.
PIC16(L)F1508/9
DS41609A-page 194 Preliminary 2011 Microchip Technology Inc.
21.3 I2C MODE OVERVIEW
The Inter-Integrated Circuit Bus (I2C) is a multi-master
serial data communication bus. Devices communicate
in a master/slave environment where the master
devices initiate the communication. A Slave device is
controlled through addressing.
The I2C bus specifies two signal connections:
• Serial Clock (SCLx)
• Serial Data (SDAx)
Figure 21-2 and Figure 21-3 show the block diagrams
of the MSSP module when operating in I2C mode.
Both the SCLx and SDAx connections are bidirectional
open-drain lines, each requiring pull-up resistors for the
supply voltage. Pulling the line to ground is considered
a logical zero and letting the line float is considered a
logical one.
Figure 21-11 shows a typical connection between two
processors configured as master and slave devices.
The I2C bus can operate with one or more master
devices and one or more slave devices.
There are four potential modes of operation for a given
device:
• Master Transmit mode
(master is transmitting data to a slave)
• Master Receive mode
(master is receiving data from a slave)
•Slave Transmit mode
(slave is transmitting data to a master)
• Slave Receive mode
(slave is receiving data from the master)
To begin communication, a master device starts out in
Master Transmit mode. The master device sends out a
Start bit followed by the address byte of the slave it
intends to communicate with. This is followed by a sin-
gle Read/Write bit, which determines whether the mas-
ter intends to transmit to or receive data from the slave
device.
If the requested slave exists on the bus, it will respond
with an Acknowledge bit, otherwise known as an ACK.
The master then continues in either Transmit mode or
Receive mode and the slave continues in the comple-
ment, either in Receive mode or Transmit mode,
respectively.
A Start bit is indicated by a high-to-low transition of the
SDAx line while the SCLx line is held high. Address and
data bytes are sent out, Most Significant bit (MSb) first.
The Read/Write bit is sent out as a logical one when the
master intends to read data from the slave, and is sent
out as a logical zero when it intends to write data to the
slave.
FIGURE 21-11: I2C MASTER/
SLAVE CONNECTION
The Acknowledge bit (ACK) is an active-low signal,
which holds the SDAx line low to indicate to the trans-
mitter that the slave device has received the transmit-
ted data and is ready to receive more.
The transition of a data bits is always performed while
the SCLx line is held low. Transitions that occur while
the SCLx line is held high are used to indicate Start and
Stop bits.
If the master intends to write to the slave, then it repeat-
edly sends out a byte of data, with the slave responding
after each byte with an ACK bit. In this example, the
master device is in Master Transmit mode and the
slave is in Slave Receive mode.
If the master intends to read from the slave, then it
repeatedly receives a byte of data from the slave, and
responds after each byte with an ACK bit. In this exam-
ple, the master device is in Master Receive mode and
the slave is Slave Transmit mode.
On the last byte of data communicated, the master
device may end the transmission by sending a Stop bit.
If the master device is in Receive mode, it sends the
Stop bit in place of the last ACK bit. A Stop bit is indi-
cated by a low-to-high transition of the SDAx line while
the SCLx line is held high.
In some cases, the master may want to maintain con-
trol of the bus and re-initiate another transmission. If
so, the master device may send another Start bit in
place of the Stop bit or last ACK bit when it is in receive
mode.
The I2C bus specifies three message protocols;
• Single message where a master writes data to a
slave.
• Single message where a master reads data from
a slave.
• Combined message where a master initiates a
minimum of two writes, or two reads, or a
combination of writes and reads, to one or more
slaves.
Master
SCLx
SDAx
SCLx
SDAx
Slave
VDD
VDD
2011 Microchip Technology Inc. Preliminary DS41609A-page 195
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When one device is transmitting a logical one, or letting
the line float, and a second device is transmitting a log-
ical zero, or holding the line low, the first device can
detect that the line is not a logical one. This detection,
when used on the SCLx line, is called clock stretching.
Clock stretching gives slave devices a mechanism to
control the flow of data. When this detection is used on
the SDAx line, it is called arbitration. Arbitration
ensures that there is only one master device communi-
cating at any single time.
21.3.1 CLOCK STRETCHING
When a slave device has not completed processing
data, it can delay the transfer of more data through the
process of clock stretching. An addressed slave device
may hold the SCLx clock line low after receiving or
sending a bit, indicating that it is not yet ready to con-
tinue. The master that is communicating with the slave
will attempt to raise the SCLx line in order to transfer
the next bit, but will detect that the clock line has not yet
been released. Because the SCLx connection is
open-drain, the slave has the ability to hold that line low
until it is ready to continue communicating.
Clock stretching allows receivers that cannot keep up
with a transmitter to control the flow of incoming data.
21.3.2 ARBITRATION
Each master device must monitor the bus for Start and
Stop bits. If the device detects that the bus is busy, it
cannot begin a new message until the bus returns to an
Idle state.
However, two master devices may try to initiate a trans-
mission on or about the same time. When this occurs,
the process of arbitration begins. Each transmitter
checks the level of the SDAx data line and compares it
to the level that it expects to find. The first transmitter to
observe that the two levels do not match, loses arbitra-
tion, and must stop transmitting on the SDAx line.
For example, if one transmitter holds the SDAx line to
a logical one (lets it float) and a second transmitter
holds it to a logical zero (pulls it low), the result is that
the SDAx line will be low. The first transmitter then
observes that the level of the line is different than
expected and concludes that another transmitter is
communicating.
The first transmitter to notice this difference is the one
that loses arbitration and must stop driving the SDAx
line. If this transmitter is also a master device, it also
must stop driving the SCLx line. It then can monitor the
lines for a Stop condition before trying to reissue its
transmission. In the meantime, the other device that
has not noticed any difference between the expected
and actual levels on the SDAx line continues with its
original transmission. It can do so without any compli-
cations, because so far, the transmission appears
exactly as expected with no other transmitter disturbing
the message.
Slave Transmit mode can also be arbitrated, when a
master addresses multiple slaves, but this is less com-
mon.
If two master devices are sending a message to two dif-
ferent slave devices at the address stage, the master
sending the lower slave address always wins arbitra-
tion. When two master devices send messages to the
same slave address, and addresses can sometimes
refer to multiple slaves, the arbitration process must
continue into the data stage.
Arbitration usually occurs very rarely, but it is a neces-
sary process for proper multi-master support.
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21.4 I2C MODE OPERATION
All MSSP I2C communication is byte oriented and
shifted out MSb first. Six SFR registers and 2 interrupt
flags interface the module with the PIC® microcon-
troller and user software. Two pins, SDAx and SCLx,
are exercised by the module to communicate with
other external I2C devices.
21.4.1 BYTE FORMAT
All communication in I2C is done in 9-bit segments. A
byte is sent from a master to a slave or vice-versa, fol-
lowed by an Acknowledge bit sent back. After the 8th
falling edge of the SCLx line, the device outputting
data on the SDAx changes that pin to an input and
reads in an acknowledge value on the next clock
pulse.
The clock signal, SCLx, is provided by the master.
Data is valid to change while the SCLx signal is low,
and sampled on the rising edge of the clock. Changes
on the SDAx line while the SCLx line is high define
special conditions on the bus, explained below.
21.4.2 DEFINITION OF I2C TERMINOLOGY
There is language and terminology in the description
of I2C communication that have definitions specific to
I2C. That word usage is defined below and may be
used in the rest of this document without explanation.
This table was adapted from the Philips I2C
specification.
21.4.3 SDAX AND SCLX PINS
Selection of any I2C mode with the SSPEN bit set,
forces the SCLx and SDAx pins to be open-drain.
These pins should be set by the user to inputs by set-
ting the appropriate TRIS bits.
21.4.4 SDAX HOLD TIME
The hold time of the SDAx pin is selected by the
SDAHT bit of the SSPxCON3 register. Hold time is the
time SDAx is held valid after the falling edge of SCLx.
Setting the SDAHT bit selects a longer 300 ns mini-
mum hold time and may help on buses with large
capacitance.
TABLE 21-2: I2C BUS TERMS
Note: Data is tied to output zero when an I2C
mode is enabled.
TERM Description
Transmitter The device which shifts data out
onto the bus.
Receiver The device which shifts data in
from the bus.
Master The device that initiates a transfer,
generates clock signals and termi-
nates a transfer.
Slave The device addressed by the mas-
ter.
Multi-master A bus with more than one device
that can initiate data transfers.
Arbitration Procedure to ensure that only one
master at a time controls the bus.
Winning arbitration ensures that
the message is not corrupted.
Synchronization Procedure to synchronize the
clocks of two or more devices on
the bus.
Idle No master is controlling the bus,
and both SDAx and SCLx lines are
high.
Active Any time one or more master
devices are controlling the bus.
Addressed
Slave
Slave device that has received a
matching address and is actively
being clocked by a master.
Matching
Address
Address byte that is clocked into a
slave that matches the value
stored in SSPxADD.
Write Request Slave receives a matching
address with R/W bit clear, and is
ready to clock in data.
Read Request Master sends an address byte with
the R/W bit set, indicating that it
wishes to clock data out of the
Slave. This data is the next and all
following bytes until a Restart or
Stop.
Clock Stretching When a device on the bus hold
SCLx low to stall communication.
Bus Collision Any time the SDAx line is sampled
low by the module while it is out-
putting and expected high state.
2011 Microchip Technology Inc. Preliminary DS41609A-page 197
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21.4.5 START CONDITION
The I2C specification defines a Start condition as a
transition of SDAx from a high to a low state while
SCLx line is high. A Start condition is always gener-
ated by the master and signifies the transition of the
bus from an Idle to an Active state. Figure 21-12
shows wave forms for Start and Stop conditions.
A bus collision can occur on a Start condition if the
module samples the SDAx line low before asserting it
low. This does not conform to the I2C Specification that
states no bus collision can occur on a Start.
21.4.6 STOP CONDITION
A Stop condition is a transition of the SDAx line from
low-to-high state while the SCLx line is high.
21.4.7 RESTART CONDITION
A Restart is valid any time that a Stop would be valid.
A master can issue a Restart if it wishes to hold the
bus after terminating the current transfer. A Restart
has the same effect on the slave that a Start would,
resetting all slave logic and preparing it to clock in an
address. The master may want to address the same or
another slave.
In 10-bit Addressing Slave mode a Restart is required
for the master to clock data out of the addressed
slave. Once a slave has been fully addressed, match-
ing both high and low address bytes, the master can
issue a Restart and the high address byte with the
R/W bit set. The slave logic will then hold the clock
and prepare to clock out data.
After a full match with R/W clear in 10-bit mode, a prior
match flag is set and maintained. Until a Stop condi-
tion, a high address with R/W clear, or high address
match fails.
21.4.8 START/STOP CONDITION INTERRUPT
MASKING
The SCIE and PCIE bits of the SSPxCON3 register
can enable the generation of an interrupt in Slave
modes that do not typically support this function. Slave
modes where interrupt on Start and Stop detect are
already enabled, these bits will have no effect.
FIGURE 21-12: I2C START AND STOP CONDITIONS
FIGURE 21-13: I2C RESTART CONDITION
Note: At least one SCLx low time must appear
before a Stop is valid, therefore, if the SDAx
line goes low then high again while the SCLx
line stays high, only the Start condition is
detected.
SDAx
SCLx
P
Stop
Condition
S
Start
Condition
Change of
Data Allowed
Change of
Data Allowed
Restart
Condition
Sr
Change of
Data Allowed
Change of
Data Allowed
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DS41609A-page 198 Preliminary 2011 Microchip Technology Inc.
21.4.9 ACKNOWLEDGE SEQUENCE
The 9th SCLx pulse for any transferred byte in I2C is
dedicated as an Acknowledge. It allows receiving
devices to respond back to the transmitter by pulling
the SDAx line low. The transmitter must release con-
trol of the line during this time to shift in the response.
The Acknowledge (ACK) is an active-low signal, pull-
ing the SDAx line low indicated to the transmitter that
the device has received the transmitted data and is
ready to receive more.
The result of an ACK is placed in the ACKSTAT bit of
the SSPxCON2 register.
Slave software, when the AHEN and DHEN bits are
set, allow the user to set the ACK value sent back to
the transmitter. The ACKDT bit of the SSPxCON2 reg-
ister is set/cleared to determine the response.
Slave hardware will generate an ACK response if the
AHEN and DHEN bits of the SSPxCON3 register are
clear.
There are certain conditions where an ACK will not be
sent by the slave. If the BF bit of the SSPxSTAT regis-
ter or the SSPOV bit of the SSPxCON1 register are
set when a byte is received.
When the module is addressed, after the 8th falling
edge of SCLx on the bus, the ACKTIM bit of the
SSPxCON3 register is set. The ACKTIM bit indicates
the acknowledge time of the active bus. The ACKTIM
Status bit is only active when the AHEN bit or DHEN
bit is enabled.
21.5 I2C Slave Mode Operation
The MSSP Slave mode operates in one of four modes
selected in the SSPM bits of SSPxCON1 register. The
modes can be divided into 7-bit and 10-bit Addressing
mode. 10-bit Addressing modes operate the same as
7-bit with some additional overhead for handling the
larger addresses.
Modes with Start and Stop bit interrupts operate the
same as the other modes with SSPxIF additionally
getting set upon detection of a Start, Restart, or Stop
condition.
21.5.1 SLAVE MODE ADDRESSES
The SSPxADD register (Register 21-6) contains the
Slave mode address. The first byte received after a
Start or Restart condition is compared against the
value stored in this register. If the byte matches the
value is loaded into the SSPxBUF register and an
interrupt is generated. If the value does not match, the
module goes idle and no indication is given to the soft-
ware that anything happened.
The SSP Mask register (Register 21-5) affects the
address matching process. See Section 21.5.9
“SSPx Mask Register” for more information.
21.5.1.1 I2C Slave 7-bit Addressing Mode
In 7-bit Addressing mode, the LSb of the received data
byte is ignored when determining if there is an address
match.
21.5.1.2 I2C Slave 10-bit Addressing Mode
In 10-bit Addressing mode, the first received byte is
compared to the binary value of ‘1 1 1 1 0 A9 A8 0’. A9
and A8 are the two MSb of the 10-bit address and
stored in bits 2 and 1 of the SSPxADD register.
After the acknowledge of the high byte the UA bit is set
and SCLx is held low until the user updates SSPxADD
with the low address. The low address byte is clocked
in and all 8 bits are compared to the low address value
in SSPxADD. Even if there is not an address match;
SSPxIF and UA are set, and SCLx is held low until
SSPxADD is updated to receive a high byte again.
When SSPxADD is updated the UA bit is cleared. This
ensures the module is ready to receive the high
address byte on the next communication.
A high and low address match as a write request is
required at the start of all 10-bit addressing communi-
cation. A transmission can be initiated by issuing a
Restart once the slave is addressed, and clocking in
the high address with the R/W bit set. The slave hard-
ware will then acknowledge the read request and pre-
pare to clock out data. This is only valid for a slave
after it has received a complete high and low address
byte match.
21.5.2 SLAVE RECEPTION
When the R/W bit of a matching received address byte
is clear, the R/W bit of the SSPxSTAT register is
cleared. The received address is loaded into the
SSPxBUF register and acknowledged.
When the overflow condition exists for a received
address, then not Acknowledge is given. An overflow
condition is defined as either bit BF of the SSPxSTAT
register is set, or bit SSPOV of the SSPxCON1 register
is set. The BOEN bit of the SSPxCON3 register modi-
fies this operation. For more information see
Register 21-4.
An MSSP interrupt is generated for each transferred
data byte. Flag bit, SSPxIF, must be cleared by soft-
ware.
When the SEN bit of the SSPxCON2 register is set,
SCLx will be held low (clock stretch) following each
received byte. The clock must be released by setting
the CKP bit of the SSPxCON1 register, except
sometimes in 10-bit mode. See Section 21.2.3 “SPI
Master Mode” for more detail.
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21.5.2.1 7-bit Addressing Reception
This section describes a standard sequence of events
for the MSSP module configured as an I2C Slave in
7-bit Addressing mode. Figure 21-14 and Figure 21-15
are used as visual references for this description.
This is a step by step process of what typically must
be done to accomplish I2C communication.
1. Start bit detected.
2. S bit of SSPxSTAT is set; SSPxIF is set if inter-
rupt on Start detect is enabled.
3. Matching address with R/W bit clear is received.
4. The slave pulls SDAx low sending an ACK to the
master, and sets SSPxIF bit.
5. Software clears the SSPxIF bit.
6. Software reads received address from
SSPxBUF clearing the BF flag.
7. If SEN = 1; Slave software sets CKP bit to
release the SCLx line.
8. The master clocks out a data byte.
9. Slave drives SDAx low sending an ACK to the
master, and sets SSPxIF bit.
10. Software clears SSPxIF.
11. Software reads the received byte from
SSPxBUF clearing BF.
12. Steps 8-12 are repeated for all received bytes
from the Master.
13. Master sends Stop condition, setting P bit of
SSPxSTAT, and the bus goes idle.
21.5.2.2 7-bit Reception with AHEN and DHEN
Slave device reception with AHEN and DHEN set
operate the same as without these options with extra
interrupts and clock stretching added after the 8th fall-
ing edge of SCLx. These additional interrupts allow the
slave software to decide whether it wants to ACK the
receive address or data byte, rather than the hard-
ware. This functionality adds support for PMBus™ that
was not present on previous versions of this module.
This list describes the steps that need to be taken by
slave software to use these options for I2C commun-
cation. Figure 21-16 displays a module using both
address and data holding. Figure 21-17 includes the
operation with the SEN bit of the SSPxCON2 register
set.
1. S bit of SSPxSTAT is set; SSPxIF is set if inter-
rupt on Start detect is enabled.
2. Matching address with R/W bit clear is clocked
in. SSPxIF is set and CKP cleared after the 8th
falling edge of SCLx.
3. Slave clears the SSPxIF.
4. Slave can look at the ACKTIM bit of the
SSPxCON3 register to determine if the SSPxIF
was after or before the ACK.
5. Slave reads the address value from SSPxBUF,
clearing the BF flag.
6. Slave sets ACK value clocked out to the master
by setting ACKDT.
7. Slave releases the clock by setting CKP.
8. SSPxIF is set after an ACK, not after a NACK.
9. If SEN = 1 the slave hardware will stretch the
clock after the ACK.
10. Slave clears SSPxIF.
11. SSPxIF set and CKP cleared after 8th falling
edge of SCLx for a received data byte.
12. Slave looks at ACKTIM bit of SSPxCON3 to
determine the source of the interrupt.
13. Slave reads the received data from SSPxBUF
clearing BF.
14. Steps 7-14 are the same for each received data
byte.
15. Communication is ended by either the slave
sending an ACK =1, or the master sending a
Stop condition. If a Stop is sent and Interrupt on
Stop Detect is disabled, the slave will only know
by polling the P bit of the SSPSTAT register.
Note: SSPxIF is still set after the 9th falling edge of
SCLx even if there is no clock stretching and
BF has been cleared. Only if NACK is sent
to master is SSPxIF not set
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DS41609A-page 200 Preliminary 2011 Microchip Technology Inc.
FIGURE 21-14: I2C SLAVE, 7-BIT ADDRESS, RECEPTION (SEN = 0, AHEN = 0, DHEN = 0)
Receiving Address
ACK
Receiving Data
ACK
Receiving Data ACK =1
A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
SDAx
SCLx
SSPxIF
BF
SSPOV
12345678 12345678 12345678
999
ACK is not sent.
SSPOV set because
SSPxBUF is still full.
Cleared by software
First byte
of data is
available
in SSPxBUF
SSPxBUF is read
SSPxIF set on 9th
falling edge of
SCLx
Cleared by software
P
Bus Master sends
Stop condition
S
From Slave to Master
2011 Microchip Technology Inc. Preliminary DS41609A-page 201
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FIGURE 21-15: I2C SLAVE, 7-BIT ADDRESS, RECEPTION (SEN = 1, AHEN = 0, DHEN = 0)
SEN SEN
A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0SDAx
SCLx 123456789 123456789 123456789 P
SSPxIF set on 9th
SCLx is not held
CKP is written to ‘1’ in software,
CKP is written to ‘1’ in software,
ACK
low because
falling edge of SCLx
releasing SCLx
ACK is not sent.
Bus Master sends
CKP
SSPOV
BF
SSPxIF
SSPOV set because
SSPxBUF is still full.
Cleared by software
First byte
of data is
available
in SSPxBUF
ACK=1
Cleared by software
SSPxBUF is read
Clock is held low until CKP is set to ‘1’
releasing SCLx
Stop condition
S
ACK
ACK
Receive Address Receive Data Receive Data
R/W=0
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DS41609A-page 202 Preliminary 2011 Microchip Technology Inc.
FIGURE 21-16: I2C SLAVE, 7-BIT ADDRESS, RECEPTION (SEN = 0, AHEN = 1, DHEN = 1)
Receiving Address Receiving Data Received Data
P
A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
SDAx
SCLx
BF
CKP
S
P
12 3 456 7 8 912345678 9
12345678
Master sends
Stop condition
S
Data is read from SSPxBUF
Cleared by software
SSPxIF is set on
9th falling edge of
SCLx, after ACK
CKP set by software,
SCLx is released
Slave software
9
ACKTIM cleared by
hardware in 9th
rising edge of SCLx
sets ACKDT to
not ACK
When DHEN=1:
CKP is cleared by
hardware on 8th falling
edge of SCLx
Slave software
clears ACKDT to
ACK the received
byte
ACKTIM set by hardware
on 8th falling edge of SCLx
When AHEN=1:
CKP is cleared by hardware
and SCLx is stretched
Address is
read from
SSBUF
ACKTIM set by hardware
on 8th falling edge of SCLx
ACK
Master Releases SDAx
to slave for ACK sequence
No interrupt
after not ACK
from Slave
ACK=1
ACK
ACKDT
ACKTIM
SSPxIF
If AHEN = 1:
SSPxIF is set
2011 Microchip Technology Inc. Preliminary DS41609A-page 203
PIC16(L)F1508/9
FIGURE 21-17: I2C SLAVE, 7-BIT ADDRESS, RECEPTION (SEN = 1, AHEN = 1, DHEN = 1)
Receiving Address Receive Data Receive Data
A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
SDAx
SCLx
SSPxIF
BF
ACKDT
CKP
S
P
ACK
S12
345678 912
34567 8 9 1234567 8 9
ACK
ACK
Cleared by software
ACKTIM is cleared by hardware
SSPxBUF can be
Set by software,
read any time before
next byte is loaded
release SCLx
on 9th rising edge of SCLx
Received
address is loaded into
SSPxBUF
Slave software clears
ACKDT to ACK
R/W = 0Master releases
SDAx to slave for ACK sequence
the received byte
When AHEN = 1;
on the 8th falling edge
of SCLx of an address
byte, CKP is cleared
ACKTIM is set by hardware
on 8th falling edge of SCLx
When DHEN = 1;
on the 8th falling edge
of SCLx of a received
data byte, CKP is cleared
Received data is
available on SSPxBUF
Slave sends
not ACK
CKP is not cleared
if not ACK
P
Master sends
Stop condition
No interrupt after
if not ACK
from Slave
ACKTIM
PIC16(L)F1508/9
DS41609A-page 204 Preliminary 2011 Microchip Technology Inc.
21.5.3 SLAVE 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, and an ACK pulse is
sent by the slave on the ninth bit.
Following the ACK, slave hardware clears the CKP bit
and the SCLx pin is held low (see Section 21.5.6
“Clock Stretching” for more detail). 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
the SCLx pin should be released by setting the CKP bit
of the SSPxCON1 register. 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.
The ACK pulse from the master-receiver is latched on
the rising edge of the ninth SCLx input pulse. This ACK
value is copied to the ACKSTAT bit of the SSPxCON2
register. If ACKSTAT is set (not ACK), then the data
transfer is complete. In this case, when the not ACK is
latched by the slave, the slave goes idle and waits 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, the SCLx pin must be
released by setting bit CKP.
An MSSP interrupt is generated for each data transfer
byte. The SSPxIF bit must be cleared by 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.
21.5.3.1 Slave Mode Bus Collision
A slave receives a Read request and begins shifting
data out on the SDAx line. If a bus collision is detected
and the SBCDE bit of the SSPxCON3 register is set,
the BCLxIF bit of the PIRx register is set. Once a bus
collision is detected, the slave goes idle and waits to be
addressed again. User software can use the BCLxIF bit
to handle a slave bus collision.
21.5.3.2 7-bit Transmission
A master device can transmit a read request to a
slave, and then clock data out of the slave. The list
below outlines what software for a slave will need to
do to accomplish a standard transmission.
Figure 21-17 can be used as a reference to this list.
1. Master sends a Start condition on SDAx and
SCLx.
2. S bit of SSPxSTAT is set; SSPxIF is set if inter-
rupt on Start detect is enabled.
3. Matching address with R/W bit set is received by
the Slave setting SSPxIF bit.
4. Slave hardware generates an ACK and sets
SSPxIF.
5. SSPxIF bit is cleared by user.
6. Software reads the received address from
SSPxBUF, clearing BF.
7. R/W is set so CKP was automatically cleared
after the ACK.
8. The slave software loads the transmit data into
SSPxBUF.
9. CKP bit is set releasing SCLx, allowing the mas-
ter to clock the data out of the slave.
10. SSPxIF is set after the ACK response from the
master is loaded into the ACKSTAT register.
11. SSPxIF bit is cleared.
12. The slave software checks the ACKSTAT bit to
see if the master wants to clock out more data.
13. Steps 9-13 are repeated for each transmitted
byte.
14. If the master sends a not ACK; the clock is not
held, but SSPxIF is still set.
15. The master sends a Restart condition or a Stop.
16. The slave is no longer addressed.
Note 1: If the master ACKs the clock will be
stretched.
2: ACKSTAT is the only bit updated on the
rising edge of SCLx (9th) rather than the
falling.
2011 Microchip Technology Inc. Preliminary DS41609A-page 205
PIC16(L)F1508/9
FIGURE 21-18: I2C SLAVE, 7-BIT ADDRESS, TRANSMISSION (AHEN = 0)
Receiving Address Automatic Transmitting Data Automatic Transmitting Data
A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
SDAx
SCLx
SSPxIF
BF
CKP
ACKSTAT
R/W
D/A
S
P
Received address
When R/W is set
R/W is copied from the
Indicates an address
is read from SSPxBUF
SCLx is always
held low after 9th SCLx
falling edge
matching address byte
has been received
Masters not ACK
is copied to
ACKSTAT
CKP is not
held for not
ACK
BF is automatically
cleared after 8th falling
edge of SCLx
Data to transmit is
loaded into SSPxBUF
Set by software
Cleared by software
ACK
ACK
ACK
R/W = 1
SP
Master sends
Stop condition
PIC16(L)F1508/9
DS41609A-page 206 Preliminary 2011 Microchip Technology Inc.
21.5.3.3 7-bit Transmission with Address
Hold Enabled
Setting the AHEN bit of the SSPxCON3 register
enables additional clock stretching and interrupt gen-
eration after the 8th falling edge of a received match-
ing address. Once a matching address has been
clocked in, CKP is cleared and the SSPxIF interrupt is
set.
Figure 21-18 displays a standard waveform of a 7-bit
Address Slave Transmission with AHEN enabled.
1. Bus starts idle.
2. Master sends Start condition; the S bit of
SSPxSTAT is set; SSPxIF is set if interrupt on
Start detect is enabled.
3. Master sends matching address with R/W bit
set. After the 8th falling edge of the SCLx line the
CKP bit is cleared and SSPxIF interrupt is gen-
erated.
4. Slave software clears SSPxIF.
5. Slave software reads ACKTIM bit of SSPxCON3
register, and R/W and D/A of the SSPxSTAT
register to determine the source of the interrupt.
6. Slave reads the address value from the
SSPxBUF register clearing the BF bit.
7. Slave software decides from this information if it
wishes to ACK or not ACK and sets the ACKDT
bit of the SSPxCON2 register accordingly.
8. Slave sets the CKP bit releasing SCLx.
9. Master clocks in the ACK value from the slave.
10. Slave hardware automatically clears the CKP bit
and sets SSPxIF after the ACK if the R/W bit is
set.
11. Slave software clears SSPxIF.
12. Slave loads value to transmit to the master into
SSPxBUF setting the BF bit.
13. Slave sets CKP bit releasing the clock.
14. Master clocks out the data from the slave and
sends an ACK value on the 9th SCLx pulse.
15. Slave hardware copies the ACK value into the
ACKSTAT bit of the SSPxCON2 register.
16. Steps 10-15 are repeated for each byte transmit-
ted to the master from the slave.
17. If the master sends a not ACK the slave
releases the bus allowing the master to send a
Stop and end the communication.
Note: SSPxBUF cannot be loaded until after the
ACK.
Note: Master must send a not ACK on the last byte
to ensure that the slave releases the SCLx
line to receive a Stop.
2011 Microchip Technology Inc. Preliminary DS41609A-page 207
PIC16(L)F1508/9
FIGURE 21-19: I2C SLAVE, 7-BIT ADDRESS, TRANSMISSION (AHEN = 1)
Receiving Address Automatic Transmitting Data Automatic Transmitting Data
A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
SDAx
SCLx
SSPxIF
BF
ACKDT
ACKSTAT
CKP
R/W
D/A
Received address
is read from SSPxBUF
BF is automatically
cleared after 8th falling
edge of SCLx
Data to transmit is
loaded into SSPxBUF
Cleared by software
Slave clears
ACKDT to ACK
address
Master’s ACK
response is copied
to SSPxSTAT
CKP not cleared
after not ACK
Set by software,
releases SCLx
ACKTIM is cleared
on 9th rising edge of SCLx
ACKTIM is set on 8th falling
edge of SCLx
When AHEN = 1;
CKP is cleared by hardware
after receiving matching
address.
When R/W = 1;
CKP is always
cleared after ACK
SP
Master sends
Stop condition
ACK
R/W = 1
Master releases SDAx
to slave for ACK sequence
ACK
ACK
ACKTIM
PIC16(L)F1508/9
DS41609A-page 208 Preliminary 2011 Microchip Technology Inc.
21.5.4 SLAVE MODE 10-BIT ADDRESS
RECEPTION
This section describes a standard sequence of events
for the MSSP module configured as an I2C slave in
10-bit Addressing mode.
Figure 21-19 and is used as a visual reference for this
description.
This is a step by step process of what must be done by
slave software to accomplish I2C communication.
1. Bus starts idle.
2. Master sends Start condition; S bit of SSPxSTAT
is set; SSPxIF is set if interrupt on Start detect is
enabled.
3. Master sends matching high address with R/W
bit clear; UA bit of the SSPxSTAT register is set.
4. Slave sends ACK and SSPxIF is set.
5. Software clears the SSPxIF bit.
6. Software reads received address from
SSPxBUF clearing the BF flag.
7. Slave loads low address into SSPxADD,
releasing SCLx.
8. Master sends matching low address byte to the
Slave; UA bit is set.
9. Slave sends ACK and SSPxIF is set.
10. Slave clears SSPxIF.
11. Slave reads the received matching address
from SSPxBUF clearing BF.
12. Slave loads high address into SSPxADD.
13. Master clocks a data byte to the slave and
clocks out the slaves ACK on the 9th SCLx
pulse; SSPxIF is set.
14. If SEN bit of SSPxCON2 is set, CKP is cleared
by hardware and the clock is stretched.
15. Slave clears SSPxIF.
16. Slave reads the received byte from SSPxBUF
clearing BF.
17. If SEN is set the slave sets CKP to release the
SCLx.
18. Steps 13-17 repeat for each received byte.
19. Master sends Stop to end the transmission.
21.5.5 10-BIT ADDRESSING WITH ADDRESS OR
DATA HOLD
Reception using 10-bit addressing with AHEN or
DHEN set is the same as with 7-bit modes. The only
difference is the need to update the SSPxADD register
using the UA bit. All functionality, specifically when the
CKP bit is cleared and SCLx line is held low are the
same. Figure 21-20 can be used as a reference of a
slave in 10-bit addressing with AHEN set.
Figure 21-21 shows a standard waveform for a slave
transmitter in 10-bit Addressing mode.
Note: Updates to the SSPxADD register are not
allowed until after the ACK sequence.
Note: If the low address does not match, SSPxIF
and UA are still set so that the slave soft-
ware can set SSPxADD back to the high
address. BF is not set because there is no
match. CKP is unaffected.
2011 Microchip Technology Inc. Preliminary DS41609A-page 209
PIC16(L)F1508/9
FIGURE 21-20: I2C SLAVE, 10-BIT ADDRESS, RECEPTION (SEN = 1, AHEN = 0, DHEN = 0)
SSPxIF
Receive First Address Byte
ACK
Receive Second Address Byte
ACK
Receive Data
ACK
Receive Data
ACK
11110
A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
SDAx
SCLx
UA
CKP
12345678912345678
912345678
9123456789P
Master sends
Stop condition
Cleared by software
Receive address is
Software updates SSPxADD
Data is read
SCLx is held low
Set by software,
while CKP =
0
from SSPxBUF
releasing SCLx
When SEN =
1
;
CKP is cleared after
9th falling edge of received byte
read from SSPxBUF
and releases SCLx
When UA =
1
;
If address matches
Set by hardware
on 9th falling edge
SSPxADD it is loaded into
SSPxBUF
SCLx is held low
S
BF
PIC16(L)F1508/9
DS41609A-page 210 Preliminary 2011 Microchip Technology Inc.
FIGURE 21-21: I2C SLAVE, 10-BIT ADDRESS, RECEPTION (SEN = 0, AHEN = 1, DHEN = 0)
Receive First Address Byte
UA
Receive Second Address Byte
UA
Receive Data
ACK
Receive Data
1 1 1 1 0
A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5SDAx
SCLx
SSPxIF
BF
ACKDT
UA
CKP
ACKTIM
12345678 9
S
ACK
ACK
12345678 91234567891
2
SSPxBUF
is read from
Received data
SSPxBUF can be
read anytime before
the next received byte
Cleared by software
falling edge of SCLx
not allowed until 9th
Update to SSPxADD is
Set CKP with software
releases SCLx
SCLx
clears UA and releases
Update of SSPxADD,
Set by hardware
on 9th falling edge
Slave software clears
ACKDT to ACK
the received byte
If when AHEN = 1;
on the 8th falling edge
of SCLx of an address
byte, CKP is cleared
ACKTIM is set by hardware
on 8th falling edge of SCLx
Cleared by software
R/W = 0
2011 Microchip Technology Inc. Preliminary DS41609A-page 211
PIC16(L)F1508/9
FIGURE 21-22: I2C SLAVE, 10-BIT ADDRESS, TRANSMISSION (SEN = 0, AHEN = 0, DHEN = 0)
Receiving Address
ACK
Receiving Second Address Byte
Sr
Receive First Address Byte
ACK
Transmitting Data Byte
1 1 1 1 0
A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
1 1 1 1 0
A9 A8 D7 D6 D5 D4 D3 D2 D1 D0SDAx
SCLx
SSPxIF
BF
UA
CKP
R/W
D/A
123456789 123456789 1234 56789 123456789
ACK = 1
P
Master sends
Stop condition
Master sends
not ACK
Master sends
Restart event
ACK
R/W = 0
S
Cleared by software
After SSPxADD is
updated, UA is cleared
and SCLx is released
High address is loaded
Received address is Data to transmit is
Set by software
Indicates an address
When R/W = 1;
R/W is copied from the
Set by hardware
UA indicates SSPxADD
SSPxBUF loaded
with received address
must be updated
has been received
loaded into SSPxBUF
releases SCLx
Masters not ACK
is copied
matching address byte
CKP is cleared on
9th falling edge of SCLx
read from SSPxBUF
back into SSPxADD
ACKSTAT
Set by hardware
PIC16(L)F1508/9
DS41609A-page 212 Preliminary 2011 Microchip Technology Inc.
21.5.6 CLOCK STRETCHING
Clock stretching occurs when a device on the bus
holds the SCLx line low, effectively pausing communi-
cation. The slave may stretch the clock to allow more
time to handle data or prepare a response for the mas-
ter device. A master device is not concerned with
stretching as anytime it is active on the bus and not
transferring data it is stretching. Any stretching done
by a slave is invisible to the master software and han-
dled by the hardware that generates SCLx.
The CKP bit of the SSPxCON1 register is used to con-
trol stretching in software. Any time the CKP bit is
cleared, the module will wait for the SCLx line to go
low and then hold it. Setting CKP will release SCLx
and allow more communication.
21.5.6.1 Normal Clock Stretching
Following an ACK if the R/W bit of SSPxSTAT is set, a
read request, the slave hardware will clear CKP. This
allows the slave time to update SSPxBUF with data to
transfer to the master. If the SEN bit of SSPxCON2 is
set, the slave hardware will always stretch the clock
after the ACK sequence. Once the slave is ready, CKP
is set by software and communication resumes.
21.5.6.2 10-bit Addressing Mode
In 10-bit Addressing mode, when the UA bit is set, the
clock is always stretched. This is the only time the
SCLx is stretched without CKP being cleared. SCLx is
released immediately after a write to SSPxADD.
21.5.6.3 Byte NACKing
When the AHEN bit of SSPxCON3 is set; CKP is
cleared by hardware after the 8th falling edge of SCLx
for a received matching address byte. When the
DHEN bit of SSPxCON3 is set, CKP is cleared after
the 8th falling edge of SCLx for received data.
Stretching after the 8th falling edge of SCLx allows the
slave to look at the received address or data and
decide if it wants to ACK the received data.
21.5.7 CLOCK SYNCHRONIZATION AND
THE CKP BIT
Any time the CKP bit is cleared, the module will wait
for the SCLx line to go low and then hold it. 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 released SCLx. This ensures that a write
to the CKP bit will not violate the minimum high time
requirement for SCLx (see Figure 21-22).
FIGURE 21-23: CLOCK SYNCHRONIZATION TIMING
Note 1: The BF bit has no effect on if the clock will
be stretched or not. This is different than
previous versions of the module that
would not stretch the clock, clear CKP, if
SSPxBUF was read before the 9th falling
edge of SCLx.
2: Previous versions of the module did not
stretch the clock for a transmission if
SSPxBUF was loaded before the 9th fall-
ing edge of SCLx. It is now always cleared
for read requests.
Note: Previous versions of the module did not
stretch the clock if the second address byte
did not match.
SDAx
SCLx
DX ‚ – 1DX
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
releases clock
Master device
asserts clock
2011 Microchip Technology Inc. Preliminary DS41609A-page 213
PIC16(L)F1508/9
21.5.8 GENERAL CALL ADDRESS SUPPORT
The addressing procedure for the I2C bus is such that
the first byte after the Start condition usually deter-
mines which device will be the slave addressed by the
master device. 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 a reserved address in the
I2C protocol, defined as address 0x00. When the
GCEN bit of the SSPxCON2 register is set, the slave
module will automatically ACK the reception of this
address regardless of the value stored in SSPxADD.
After the slave clocks in an address of all zeros with
the R/W bit clear, an interrupt is generated and slave
software can read SSPxBUF and respond.
Figure 21-23 shows a General Call reception
sequence.
In 10-bit Address mode, the UA bit will not be set on
the reception of the general call address. The slave
will prepare to receive the second byte as data, just as
it would in 7-bit mode.
If the AHEN bit of the SSPxCON3 register is set, just
as with any other address reception, the slave hard-
ware will stretch the clock after the 8th falling edge of
SCLx. The slave must then set its ACKDT value and
release the clock with communication progressing as it
would normally.
FIGURE 21-24: SLAVE MODE GENERAL CALL ADDRESS SEQUENCE
21.5.9 SSPx MASK REGISTER
An SSPx Mask (SSPxMSK) register (Register 21-5) is
available in I2C Slave mode as a mask for the value
held in the SSPxSR register during an address
comparison operation. A zero (‘0’) bit in the SSPxMSK
register has the effect of making the corresponding bit
of the received address a “don’t care”.
This register is reset to all ‘1’s upon any Reset
condition and, therefore, has no effect on standard
SSPx operation until written with a mask value.
The SSPx Mask register is active during:
• 7-bit Address mode: address compare of A<7:1>.
• 10-bit Address mode: address compare of A<7:0>
only. The SSPx mask has no effect during the
reception of the first (high) byte of the address.
SDAx
SCLx
S
SSPxIF
BF (SSPxSTAT<0>)
Cleared by software
SSPxBUF is read
R/W = 0
ACK
General Call Address
Address is compared to General Call Address
Receiving Data ACK
123456789123456789
D7 D6 D5 D4 D3 D2 D1 D0
after ACK, set interrupt
GCEN (SSPxCON2<7>)
’1’
PIC16(L)F1508/9
DS41609A-page 214 Preliminary 2011 Microchip Technology Inc.
21.6 I2C MASTER MODE
Master mode is enabled by setting and clearing the
appropriate SSPM bits in the SSPxCON1 register and
by setting the SSPEN bit. In Master mode, the SDAx
and SCKx pins must be configured as inputs. The
MSSP peripheral hardware will override the output
driver TRIS controls when necessary to drive the pins
low.
Master mode of operation is supported by interrupt
generation on the detection of the Start and Stop con-
ditions. The Stop (P) and Start (S) bits are cleared from
a Reset or when the MSSPx module is disabled. Con-
trol of the I2C bus may be taken when the P bit is set,
or the bus is idle.
In Firmware Controlled Master mode, user code
conducts all I2C bus operations based on Start and
Stop bit condition detection. Start and Stop condition
detection is the only active circuitry in this mode. All
other communication is done by the user software
directly manipulating the SDAx and SCLx lines.
The following events will cause the SSPx Interrupt Flag
bit, SSPxIF, to be set (SSPx interrupt, if enabled):
• Start condition detected
• Stop condition detected
• Data transfer byte transmitted/received
• Acknowledge transmitted/received
• Repeated Start generated
21.6.1 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 con-
tains 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.
A Baud Rate Generator is used to set the clock fre-
quency output on SCLx. See Section 21.7 “Baud
Rate Generator” for more detail.
Note 1: The MSSPx module, when configured in
I2C Master mode, does not allow queue-
ing 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
2: When in Master mode, Start/Stop detec-
tion is masked and an interrupt is gener-
ated when the SEN/PEN bit is cleared and
the generation is complete.
2011 Microchip Technology Inc. Preliminary DS41609A-page 215
PIC16(L)F1508/9
21.6.2 CLOCK ARBITRATION
Clock arbitration occurs when the master, during any
receive, transmit or Repeated Start/Stop condition,
releases 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<7:0> 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 21-25).
FIGURE 21-25: BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
21.6.3 WCOL STATUS FLAG
If the user writes the SSPxBUF when a Start, Restart,
Stop, Receive or Transmit sequence is in progress, the
WCOL bit is set and the contents of the buffer are
unchanged (the write does not occur). Any time the
WCOL bit is set it indicates that an action on SSPxBUF
was attempted while the module was not idle.
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
Note: Because queueing of events is not
allowed, writing to the lower 5 bits of
SSPxCON2 is disabled until the Start
condition is complete.
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21.6.4 I2C MASTER MODE START
CONDITION TIMING
To initiate a Start condition, the user sets the Start
Enable bit, SEN bit of the SSPxCON2 register. If the
SDAx and SCLx pins are sampled high, the Baud Rate
Generator is reloaded with the contents of
SSPxADD<7:0> 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 condition and causes the S bit
of the SSPxSTAT1 register to be set. Following this,
the Baud Rate Generator is reloaded with the contents
of SSPxADD<7:0> and resumes its count. When the
Baud Rate Generator times out (TBRG), the SEN bit of
the SSPxCON2 register will be automatically cleared
by hardware; the Baud Rate Generator is suspended,
leaving the SDAx line held low and the Start condition
is complete.
FIGURE 21-26: FIRST START BIT TIMING
Note 1: 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.
2: The Philips I2C Specification states that a
bus collision cannot occur on a Start.
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
2011 Microchip Technology Inc. Preliminary DS41609A-page 217
PIC16(L)F1508/9
21.6.5 I2C MASTER MODE REPEATED
START CONDITION TIMING
A Repeated Start condition occurs when the RSEN bit
of the SSPxCON2 register is programmed high and the
master state machine is no longer active. 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 and begins counting. The SDAx pin is released
(brought high) for one Baud Rate Generator count
(TBRG). When the Baud Rate Generator times out, if
SDAx is sampled high, the SCLx pin will be deasserted
(brought high). When SCLx is sampled high, the Baud
Rate Generator is reloaded 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. SCLx is
asserted low. Following this, the RSEN bit of the
SSPxCON2 register 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 of the
SSPxSTAT register will be set. The SSPxIF bit will not
be set until the Baud Rate Generator has timed out.
FIGURE 21-27: REPEAT 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’.
SDAx
SCLx
Repeated Start
Write to SSPxCON2
Write to SSPxBUF occurs here
At completion of Start bit,
hardware clears RSEN bit
1st bit
S bit set by hardware
TBRG
TBRG
SDAx = 1,SDAx = 1,
SCLx (no change) SCLx = 1
occurs here
TBRG TBRG TBRG
and sets SSPxIF
Sr
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DS41609A-page 218 Preliminary 2011 Microchip Technology Inc.
21.6.6 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 simply
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 trans-
mission. Each bit of address/data will be shifted out
onto the SDAx pin after the falling edge of SCLx is
asserted. SCLx is held low for one Baud Rate Genera-
tor rollover count (TBRG). Data should be valid before
SCLx is released high. 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 prop-
erly. The status of ACK is written into the ACKSTAT bit
on the rising 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 21-27).
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
release 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 of the
SSPxCON2 register. Following the falling edge of the
ninth clock transmission of the address, the SSPxIF 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.
21.6.6.1 BF Status Flag
In Transmit mode, the BF bit of the SSPxSTAT register
is set when the CPU writes to SSPxBUF and is cleared
when all 8 bits are shifted out.
21.6.6.2 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 does not occur).
WCOL must be cleared by software before the next
transmission.
21.6.6.3 ACKSTAT Status Flag
In Transmit mode, the ACKSTAT bit of the SSPxCON2
register is cleared when the slave has sent an Acknowl-
edge (ACK =0) and is set when the slave does not
Acknowledge (ACK =1). A slave sends an Acknowl-
edge when it has recognized its address (including a
general call), or when the slave has properly received
its data.
21.6.6.4 Typical transmit sequence:
1. The user generates a Start condition by setting
the SEN bit of the SSPxCON2 register.
2. SSPxIF is set by hardware on completion of the
Start.
3. SSPxIF is cleared by software.
4. The MSSPx module will wait the required start
time before any other operation takes place.
5. The user loads the SSPxBUF with the slave
address to transmit.
6. Address is shifted out the SDAx pin until all 8 bits
are transmitted. Transmission begins as soon
as SSPxBUF is written to.
7. The MSSPx module shifts in the ACK bit from
the slave device and writes its value into the
ACKSTAT bit of the SSPxCON2 register.
8. The MSSPx module generates an interrupt at
the end of the ninth clock cycle by setting the
SSPxIF bit.
9. The user loads the SSPxBUF with eight bits of
data.
10. Data is shifted out the SDAx pin until all 8 bits
are transmitted.
11. The MSSPx module shifts in the ACK bit from
the slave device and writes its value into the
ACKSTAT bit of the SSPxCON2 register.
12. Steps 8-11 are repeated for all transmitted data
bytes.
13. The user generates a Stop or Restart condition
by setting the PEN or RSEN bits of the
SSPxCON2 register. Interrupt is generated once
the Stop/Restart condition is complete.
2011 Microchip Technology Inc. Preliminary DS41609A-page 219
PIC16(L)F1508/9
FIGURE 21-28: 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 by software service routine
SSPxBUF is written by software
from SSP 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 by software
SSPxBUF written
PEN
R/W
Cleared by software
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DS41609A-page 220 Preliminary 2011 Microchip Technology Inc.
21.6.7 I2C MASTER MODE RECEPTION
Master mode reception is enabled by programming the
Receive Enable bit, RCEN bit of the SSPxCON2
register.
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, ACKEN
bit of the SSPxCON2 register.
21.6.7.1 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.
21.6.7.2 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.
21.6.7.3 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 does not occur).
21.6.7.4 Typical Receive Sequence:
1. The user generates a Start condition by setting
the SEN bit of the SSPxCON2 register.
2. SSPxIF is set by hardware on completion of the
Start.
3. SSPxIF is cleared by software.
4. User writes SSPxBUF with the slave address to
transmit and the R/W bit set.
5. Address is shifted out the SDAx pin until all 8 bits
are transmitted. Transmission begins as soon
as SSPxBUF is written to.
6. The MSSP module shifts in the ACK bit from the
slave device and writes its value into the
ACKSTAT bit of the SSPxCON2 register.
7. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the
SSPxIF bit.
8. User sets the RCEN bit of the SSPxCON2 regis-
ter and the Master clocks in a byte from the slave.
9. After the 8th falling edge of SCLx, SSPxIF and
BF are set.
10. Master clears SSPxIF and reads the received
byte from SSPxBUF, clears BF.
11. Master sets ACK value sent to slave in ACKDT
bit of the SSPxCON2 register and initiates the
ACK by setting the ACKEN bit.
12. Masters ACK is clocked out to the Slave and
SSPxIF is set.
13. User clears SSPxIF.
14. Steps 8-13 are repeated for each received byte
from the slave.
15. Master sends a not ACK or Stop to end
communication.
Note: The MSSPx module must be in an Idle
state before the RCEN bit is set or the
RCEN bit will be disregarded.
2011 Microchip Technology Inc. Preliminary DS41609A-page 221
PIC16(L)F1508/9
FIGURE 21-29: 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 12345678912345678 9 1234
Bus master
terminates
transfer
ACK
Receiving Data from Slave
Receiving Data from Slave
D0
D1
D2
D3D4
D5
D6D7
ACK
R/W
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 by software
start XMIT
SEN = 0
SSPOV
SDAx = 0, SCLx = 1
while CPU
(SSPxSTAT<0>)
ACK
Cleared by software
Cleared by software
Set SSPxIF interrupt
at end of receive
Set P bit
(SSPxSTAT<4>)
and SSPxIF
Cleared in
software
ACK from Master
Set SSPxIF at end
Set SSPxIF interrupt
at end of Acknowledge
sequence
Set SSPxIF interrupt
at end of Acknow-
ledge sequence
of receive
Set ACKEN, start Acknowledge sequence
SSPOV is set because
SSPxBUF is still full
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 by software
SDAx = ACKDT = 0
Last bit is shifted into SSPxSR and
contents are unloaded into SSPxBUF
RCEN
Master configured as a receiver
by programming SSPxCON2<3> (RCEN = 1)
RCEN cleared
automatically
ACK from Master
SDAx = ACKDT = 0 RCEN cleared
automatically
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DS41609A-page 222 Preliminary 2011 Microchip Technology Inc.
21.6.8 ACKNOWLEDGE SEQUENCE
TIMING
An Acknowledge sequence is enabled by setting the
Acknowledge Sequence Enable bit, ACKEN bit of the
SSPxCON2 register. 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 Idle mode
(Figure 21-29).
21.6.8.1 WCOL Status Flag
If the user writes the SSPxBUF when an Acknowledge
sequence is in progress, then the WCOL bit is set and
the contents of the buffer are unchanged (the write
does not occur).
21.6.9 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 bit of the SSPxCON2 register. 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 of the
SSPxSTAT register is set. A TBRG later, the PEN bit is
cleared and the SSPxIF bit is set (Figure 21-30).
21.6.9.1 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 does
not occur).
FIGURE 21-30: 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
2011 Microchip Technology Inc. Preliminary DS41609A-page 223
PIC16(L)F1508/9
FIGURE 21-31: STOP CONDITION RECEIVE OR TRANSMIT MODE
21.6.10 SLEEP OPERATION
While in Sleep mode, the I2C slave 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).
21.6.11 EFFECTS OF A RESET
A Reset disables the MSSP module and terminates the
current transfer.
21.6.12 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 of the SSPxSTAT register is
set, or the bus is idle, with both the S and P bits clear.
When the bus is busy, enabling the SSP 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 by
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
21.6.13 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 is
‘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 21-31).
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 ser-
vices the bus collision Interrupt Service Routine and if
the I2C bus is free, the user can resume communica-
tion by asserting a Start condition.
If a Start, Repeated Start, Stop or Acknowledge condi-
tion was in progress when the bus collision occurred, the
condition is aborted, the SDAx and SCLx lines are deas-
serted and the respective control bits in the SSPxCON2
register are cleared. When the user services the bus col-
lision 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 deter-
mination 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 setup Stop condition
ACK
P
TBRG
PEN bit (SSPxCON2<2>) is cleared by
hardware and the SSPxIF bit is set
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DS41609A-page 224 Preliminary 2011 Microchip Technology Inc.
FIGURE 21-32: 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 does not match what is driven
Bus collision has occurred.
Set bus collision
interrupt (BCLxIF)
by the master.
by master
Data changes
while SCLx = 0
2011 Microchip Technology Inc. Preliminary DS41609A-page 225
PIC16(L)F1508/9
21.6.13.1 Bus Collision During a Start
Condition
During a Start condition, a bus collision occurs if:
a) SDA or SCL are sampled low at the beginning of
the Start condition (Figure 21-32).
b) SCL is sampled low before SDAx is asserted
low (Figure 21-33).
During a Start condition, both the SDAx and the SCL
pins are monitored.
If the SDA pin is already low, or the SCL pin is already
low, then all of the following occur:
• the Start condition is aborted,
• the BCL1IF flag is set and
• the MSSP module is reset to its Idle state
(Figure 21-32).
The Start condition begins with the SDAx and SCLx
pins deasserted. When the SDAx pin is sampled high,
the Baud Rate Generator is loaded and counts down. 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 21-34). If, however, a ‘1’ is sampled on the SDA
pin, the SDA pin is asserted low at the end of the BRG
count. The Baud Rate Generator is then reloaded and
counts down to zero; if the SCL pin is sampled as ‘0’
during this time, a bus collision does not occur. At the
end of the BRG count, the SCL pin is asserted low.
FIGURE 21-33: BUS COLLISION DURING START CONDITION (SDAX ONLY)
Note: The reason that bus collision is not a fac-
tor 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
collision because the two masters must be
allowed to arbitrate the first address fol-
lowing 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
SSP 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 by software
SSPxIF and BCLxIF are
cleared by software
Set BCLxIF,
Start condition. Set BCLxIF.
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DS41609A-page 226 Preliminary 2011 Microchip Technology Inc.
FIGURE 21-34: BUS COLLISION DURING START CONDITION (SCLX = 0)
FIGURE 21-35: BRG RESET DUE TO SDA 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
by software
bus collision occurs. Set BCLxIF.
SCLx = 0 before BRG time-out,
’0’’0’
’0’’0’
SDAx
SCLx
SEN
Set S
Less than TBRG TBRG
SDAx = 0, SCLx = 1
BCLxIF
S
SSPxIF
S
Interrupts cleared
by 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
2011 Microchip Technology Inc. Preliminary DS41609A-page 227
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21.6.13.2 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 low level to 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 releases SDAx and the pin is allowed to
float high, the BRG is loaded with SSPxADD and
counts down to zero. 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 21-35).
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 21-36.
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 21-36: BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)
FIGURE 21-37: BUS COLLISION DURING REPEATED START CONDITION (CASE 2)
SDAx
SCLx
RSEN
BCLxIF
S
SSPxIF
Sample SDAx when SCLx goes high.
If SDAx = 0, set BCLxIF and release SDAx and SCLx.
Cleared by software
’0’
’0’
SDAx
SCLx
BCLxIF
RSEN
S
SSPxIF
Interrupt cleared
by software
SCLx goes low before SDAx,
set BCLxIF. Release SDAx and SCLx.
TBRG TBRG
’0’
PIC16(L)F1508/9
DS41609A-page 228 Preliminary 2011 Microchip Technology Inc.
21.6.13.3 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 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 21-37). 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 21-38).
FIGURE 21-38: BUS COLLISION DURING A STOP CONDITION (CASE 1)
FIGURE 21-39: 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’
2011 Microchip Technology Inc. Preliminary DS41609A-page 229
PIC16(L)F1508/9
TABLE 21-3: SUMMARY OF 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 PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IE TMR1IE 79
PIE2 OSFIE C2IE C1IE —BCL1IE NCO1IE — — 80
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
PIR2 OSFIF C2IF C1IF —BCL1IF NCO1IF — — 83
TRISA — — TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
SSP1ADD ADD<7:0> 235
SSP1BUF MSSP Receive Buffer/Transmit Register 187*
SSP1CON1 WCOL SSPOV SSPEN CKP SSPM<3:0> 232
SSP1CON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 233
SSP1CON3 ACKTIM PCIE SCIE BOEN SDAHT SBCDE AHEN DHEN 234
SSP1MSK MSK<7:0> 235
SSP1STAT SMP CKE D/A PSR/WUA BF 231
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used by the MSSP module in I2C™ mode.
* Page provides register information.
Note 1: Unimplemented, read as ‘1’.
PIC16(L)F1508/9
DS41609A-page 230 Preliminary 2011 Microchip Technology Inc.
21.7 BAUD RATE GENERATOR
The MSSP module has a Baud Rate Generator avail-
able for clock generation in both I2C and SPI Master
modes. The Baud Rate Generator (BRG) reload value
is placed in the SSPxADD register (Register 21-6).
When a write occurs to SSPxBUF, the Baud Rate Gen-
erator will automatically begin counting down.
Once the given operation is complete, the internal clock
will automatically stop counting and the clock pin will
remain in its last state.
An internal signal “Reload” in Figure 21-39 triggers the
value from SSPxADD to be loaded into the BRG
counter. This occurs twice for each oscillation of the
module clock line. The logic dictating when the reload
signal is asserted depends on the mode the MSSP is
being operated in.
Table 21-4 demonstrates clock rates based on
instruction cycles and the BRG value loaded into
SSPxADD.
EQUATION 21-1:
FIGURE 21-40: BAUD RATE GENERATOR BLOCK DIAGRAM
TABLE 21-4: MSSP CLOCK RATE W/BRG
FCLOCK FOSC
SSPxADD 1+4
-------------------------------------------------=
Note: Values of 0x00, 0x01 and 0x02 are not valid
for SSPxADD when used as a Baud Rate
Generator for I2C. This is an implementation
limitation.
FOSC FCY BRG Value FCLOCK
(2 Rollovers of BRG)
16 MHz 4 MHz 09h 400 kHz(1)
16 MHz 4 MHz 0Ch 308 kHz
16 MHz 4 MHz 27h 100 kHz
4 MHz 1 MHz 09h 100 kHz
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.
SSPM<3:0>
BRG Down Counter
SSPxCLK FOSC/2
SSPxADD<7:0>
SSPM<3:0>
SCLx
Reload
Control
Reload
2011 Microchip Technology Inc. Preliminary DS41609A-page 231
PIC16(L)F1508/9
REGISTER 21-1: SSPSTAT: SSP STATUS REGISTER
R/W-0/0 R/W-0/0 R-0/0 R-0/0 R-0/0 R-0/0 R-0/0 R-0/0
SMP CKE D/A PSR/WUA BF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 SMP: SPI Data Input 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
In I2 C 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: SPI Clock Edge Select bit (SPI mode only)
In SPI Master or Slave mode:
1 = Transmit occurs on transition from active to Idle clock state
0 = Transmit occurs on transition from Idle to active clock state
In I2 C™ mode only:
1 = Enable input logic so that thresholds are compliant with SMBus specification
0 = Disable SMBus specific inputs
bit 5 D/A: Data/Address bit (I2C mode only)
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
(I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is cleared.)
1 = Indicates that a Stop bit has been detected last (this bit is ‘0’ on Reset)
0 = Stop bit was not detected last
bit 3 S: Start bit
(I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is cleared.)
1 = Indicates that a Start bit has been detected last (this bit is ‘0’ on Reset)
0 = Start bit was not detected last
bit 2 R/W: Read/Write bit information (I2C mode only)
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.
In I2 C Slave mode:
1 = Read
0 =Write
In I2 C Master mode:
1 = Transmit is in progress
0 = Transmit is not in progress
OR-ing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the MSSP is in Idle mode.
bit 1 UA: Update Address bit (10-bit I2C 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
Receive (SPI and I2 C modes):
1 = Receive complete, SSPxBUF is full
0 = Receive not complete, SSPxBUF is empty
Transmit (I2 C mode only):
1 = Data transmit in progress (does not include the ACK and Stop bits), SSPxBUF is full
0 = Data transmit complete (does not include the ACK and Stop bits), SSPxBUF is empty
PIC16(L)F1508/9
DS41609A-page 232 Preliminary 2011 Microchip Technology Inc.
REGISTER 21-2: SSPXCON1: SSP CONTROL REGISTER 1
R/C/HS-0/0 R/C/HS-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
WCOL SSPOV SSPEN CKP SSPM<3:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared HS = Bit is set by hardware C = User cleared
bit 7 WCOL: Write Collision Detect bit
Master mode:
1 = A write to the SSPxBUF register was attempted while the I2C conditions were not valid for a transmission to be started
0 = No collision
Slave mode:
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)
In SPI 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. In Slave mode, the user must read the SSPxBUF, even if only transmitting data, to avoid
setting overflow. In Master mode, the overflow bit is not set since each new reception (and transmission) is initiated by writing to the
SSPxBUF register (must be cleared in software).
0 = No overflow
In I2 C mode:
1 = A byte is received while the SSPxBUF register is still holding the previous byte. SSPOV is a “don’t care” in Transmit mode
(must be cleared in software).
0 = No overflow
bit 5 SSPEN: Synchronous Serial Port Enable bit
In both modes, when enabled, these pins must be properly configured as input or output
In SPI mode:
1 = Enables serial port and configures SCKx, SDOx, SDIx and SSx as the source of the serial port pins(2)
0 = Disables serial port and configures these pins as I/O port pins
In I2 C mode:
1 = Enables the serial port and configures the SDAx and SCLx pins as the source of the serial port pins(3)
0 = Disables serial port and configures these pins as I/O port pins
bit 4 CKP: Clock Polarity Select bit
In SPI mode:
1 = Idle state for clock is a high level
0 = Idle state for clock is a low level
In I2 C Slave mode:
SCLx release control
1 = Enable clock
0 = Holds clock low (clock stretch). (Used to ensure data setup time.)
In I2 C Master mode:
Unused in this mode
bit 3-0 SSPM<3:0>: Synchronous Serial Port Mode Select bits
0000 = SPI Master mode, clock = FOSC/4
0001 = SPI Master mode, clock = FOSC/16
0010 = SPI Master mode, clock = FOSC/64
0011 = SPI Master mode, clock = TMR2 output/2
0100 = SPI Slave mode, clock = SCKx pin, SS pin control enabled
0101 = SPI Slave mode, clock = SCKx pin, SS pin control disabled, SSx can be used as I/O pin
0110 = I2C Slave mode, 7-bit address
0111 = I2C Slave mode, 10-bit address
1000 = I2C Master mode, clock = FOSC/(4 * (SSPxADD+1))(4)
1001 = Reserved
1010 = SPI Master mode, clock = FOSC/(4 * (SSPxADD+1))(5)
1011 = I2C firmware controlled Master mode (Slave idle)
1100 = Reserved
1101 = Reserved
1110 = I2C Slave mode, 7-bit address with Start and Stop bit interrupts enabled
1111 = I2C Slave mode, 10-bit address with Start and Stop bit interrupts enabled
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: When enabled, the SDAx and SCLx pins must be configured as inputs.
4: SSPxADD values of 0, 1 or 2 are not supported for I2C mode.
5: SSPxADD value of ‘0’ is not supported. Use SSPM = 0000 instead.
2011 Microchip Technology Inc. Preliminary DS41609A-page 233
PIC16(L)F1508/9
REGISTER 21-3: SSPXCON2: SSP CONTROL REGISTER 2
R/W-0/0 R-0/0 R/W-0/0 R/S/HS-0/0 R/S/HS-0/0 R/S/HS-0/0 R/S/HS-0/0 R/W/HS-0/0
GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared HC = Cleared by hardware S = User set
bit 7 GCEN: General Call Enable bit (in I2C Slave mode only)
1 = Enable interrupt when a general call address (0x00 or 00h) is received in the SSPxSR
0 = General call address disabled
bit 6 ACKSTAT: Acknowledge Status bit (in I2C mode only)
1 = Acknowledge was not received
0 = Acknowledge was received
bit 5 ACKDT: Acknowledge Data bit (in I2C mode only)
In Receive mode:
Value transmitted when the user initiates an Acknowledge sequence at the end of a receive
1 = Not Acknowledge
0 = Acknowledge
bit 4 ACKEN: Acknowledge Sequence Enable bit (in I2C Master mode only)
In Master Receive mode:
1 = Initiate 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 (in I2C Master mode only)
1 = Enables Receive mode for I2C
0 = Receive idle
bit 2 PEN: Stop Condition Enable bit (in I2C Master mode only)
SCKx Release Control:
1 = Initiate Stop condition on SDAx and SCLx pins. Automatically cleared by hardware.
0 = Stop condition Idle
bit 1 RSEN: Repeated Start Condition Enabled bit (in I2C Master mode only)
1 = Initiate Repeated Start condition on SDAx and SCLx pins. Automatically cleared by hardware.
0 = Repeated Start condition Idle
bit 0 SEN: Start Condition Enabled bit (in I2C Master mode only)
In Master mode:
1 = Initiate Start condition on SDAx and SCLx pins. Automatically cleared by hardware.
0 = Start condition Idle
In Slave mode:
1 = Clock stretching is enabled for both slave transmit and slave receive (stretch enabled)
0 = Clock stretching is disabled
Note 1: For bits ACKEN, RCEN, PEN, RSEN, SEN: If the I2C module is not in the Idle mode, this bit may not be
set (no spooling) and the SSPxBUF may not be written (or writes to the SSPxBUF are disabled).
PIC16(L)F1508/9
DS41609A-page 234 Preliminary 2011 Microchip Technology Inc.
REGISTER 21-4: SSPXCON3: SSP CONTROL REGISTER 3
R-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
ACKTIM PCIE SCIE BOEN SDAHT SBCDE AHEN DHEN
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 ACKTIM: Acknowledge Time Status bit (I2C mode only)(3)
1 = Indicates the I2C bus is in an Acknowledge sequence, set on 8TH falling edge of SCLx clock
0 = Not an Acknowledge sequence, cleared on 9TH rising edge of SCLx clock
bit 6 PCIE: Stop Condition Interrupt Enable bit (I2C mode only)
1 = Enable interrupt on detection of Stop condition
0 = Stop detection interrupts are disabled(2)
bit 5 SCIE: Start Condition Interrupt Enable bit (I2C mode only)
1 = Enable interrupt on detection of Start or Restart conditions
0 = Start detection interrupts are disabled(2)
bit 4 BOEN: Buffer Overwrite Enable bit
In SPI Slave mode:(1)
1 = SSPxBUF updates every time that a new data byte is shifted in ignoring the BF bit
0 = If new byte is received with BF bit of the SSPxSTAT register already set, SSPOV bit of the
SSPxCON1 register is set, and the buffer is not updated
In I2C Master mode:
This bit is ignored.
In I2C Slave mode:
1 = SSPxBUF is updated and ACK is generated for a received address/data byte, ignoring the
state of the SSPOV bit only if the BF bit = 0.
0 = SSPxBUF is only updated when SSPOV is clear
bit 3 SDAHT: SDAx Hold Time Selection bit (I2C mode only)
1 = Minimum of 300 ns hold time on SDAx after the falling edge of SCLx
0 = Minimum of 100 ns hold time on SDAx after the falling edge of SCLx
bit 2 SBCDE: Slave Mode Bus Collision Detect Enable bit (I2C Slave mode only)
If on the rising edge of SCLx, SDAx is sampled low when the module is outputting a high state, the
BCLxIF bit of the PIR2 register is set, and bus goes idle
1 = Enable slave bus collision interrupts
0 = Slave bus collision interrupts are disabled
bit 1 AHEN: Address Hold Enable bit (I2C Slave mode only)
1 = Following the 8th falling edge of SCLx for a matching received address byte, CKP bit of the
SSPxCON1 register will be cleared and the SCLx will be held low.
0 = Address holding is disabled
bit 0 DHEN: Data Hold Enable bit (I2C Slave mode only)
1 = Following the 8th falling edge of SCLx for a received data byte, slave hardware clears the CKP bit
of the SSPxCON1 register and SCLx is held low.
0 = Data holding is disabled
Note 1: For daisy-chained SPI operation, allows the user to ignore all but the last received byte. SSPOV is still set
when a new byte is received and BF = 1, but hardware continues to write the most recent byte to SSPxBUF.
2: This bit has no effect in Slave modes that Start and Stop condition detection is explicitly listed as enabled.
3: The ACKTIM Status bit is only active when the AHEN bit or DHEN bit is set.
2011 Microchip Technology Inc. Preliminary DS41609A-page 235
PIC16(L)F1508/9
REGISTER 21-5: SSPXMSK: SSP MASK REGISTER
R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1 R/W-1/1
MSK<7:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-1 MSK<7:1>: Mask bits
1 = The received address bit n is compared to SSPxADD<n> to detect I2C address match
0 = The received address bit n is not used to detect I2C address match
bit 0 MSK<0>: Mask bit for I2C Slave mode, 10-bit Address
I2C Slave mode, 10-bit address (SSPM<3:0> = 0111 or 1111):
1 = The received address bit 0 is compared to SSPxADD<0> to detect I2C address match
0 = The received address bit 0 is not used to detect I2C address match
I2C Slave mode, 7-bit address, the bit is ignored
REGISTER 21-6: SSPXADD: MSSP ADDRESS AND BAUD RATE REGISTER (I2C MODE)
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
ADD<7:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
Master mode:
bit 7-0 ADD<7:0>: Baud Rate Clock Divider bits
SCLx pin clock period = ((ADD<7:0> + 1) *4)/FOSC
10-Bit Slave mode — Most Significant Address Byte:
bit 7-3 Not used: Unused for Most Significant Address Byte. Bit state of this register is a “don’t care”. Bit pat-
tern sent by master is fixed by I2C specification and must be equal to ‘11110’. However, those bits are
compared by hardware and are not affected by the value in this register.
bit 2-1 ADD<2:1>: Two Most Significant bits of 10-bit address
bit 0 Not used: Unused in this mode. Bit state is a “don’t care”.
10-Bit Slave mode — Least Significant Address Byte:
bit 7-0 ADD<7:0>: Eight Least Significant bits of 10-bit address
7-Bit Slave mode:
bit 7-1 ADD<7:1>: 7-bit address
bit 0 Not used: Unused in this mode. Bit state is a “don’t care”.
PIC16(L)F1508/9
DS41609A-page 236 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 237
PIC16(L)F1508/9
22.0 ENHANCED UNIVERSAL
SYNCHRONOUS
ASYNCHRONOUS RECEIVER
TRANSMITTER (EUSART)
The Enhanced Universal Synchronous Asynchronous
Receiver Transmitter (EUSART) module is a serial I/O
communications peripheral. It contains all the clock
generators, shift registers and data buffers necessary
to perform an input or output serial data transfer
independent of device program execution. The
EUSART, also known as a Serial Communications
Interface (SCI), can be configured as a full-duplex
asynchronous system or half-duplex synchronous
system. Full-Duplex mode is useful for
communications with peripheral systems, such as CRT
terminals and personal computers. Half-Duplex
Synchronous mode is intended for communications
with peripheral devices, such as A/D or D/A integrated
circuits, serial EEPROMs or other microcontrollers.
These devices typically do not have internal clocks for
baud rate generation and require the external clock
signal provided by a master synchronous device.
The EUSART module includes the following capabilities:
• Full-duplex asynchronous transmit and receive
• Two-character input buffer
• One-character output buffer
• Programmable 8-bit or 9-bit character length
• Address detection in 9-bit mode
• Input buffer overrun error detection
• Received character framing error detection
• Half-duplex synchronous master
• Half-duplex synchronous slave
• Programmable clock polarity in synchronous
modes
• Sleep operation
The EUSART module implements the following
additional features, making it ideally suited for use in
Local Interconnect Network (LIN) bus systems:
• Automatic detection and calibration of the baud rate
• Wake-up on Break reception
• 13-bit Break character transmit
Block diagrams of the EUSART transmitter and
receiver are shown in Figure 22-1 and Figure 22-2.
FIGURE 22-1: EUSART TRANSMIT BLOCK DIAGRAM
TXIF
TXIE
Interrupt
TXEN
TX9D
MSb LSb
Data Bus
TXREG Register
Transmit Shift Register (TSR)
(8) 0
TX9
TRMT SPEN
TX/CK pin
Pin Buffer
and Control
8
SPBRGL
SPBRGH
BRG16
FOSC ÷ n
n
+ 1 Multiplier x4 x16 x64
SYNC 1X00 0
BRGH X110 0
BRG16 X101 0
Baud Rate Generator
•••
PIC16(L)F1508/9
DS41609A-page 238 Preliminary 2011 Microchip Technology Inc.
FIGURE 22-2: EUSART RECEIVE BLOCK DIAGRAM
The operation of the EUSART module is controlled
through three registers:
• Transmit Status and Control (TXSTA)
• Receive Status and Control (RCSTA)
• Baud Rate Control (BAUDCON)
These registers are detailed in Register 22-1,
Register 22-2 and Register 22-3, respectively.
When the receiver or transmitter section is not enabled
then the corresponding RX or TX pin may be used for
general purpose input and output.
RX/DT pin
Pin Buffer
and Control
SPEN
Data
Recovery
CREN OERR
FERR
RSR Register
MSb LSb
RX9D RCREG Register FIFO
Interrupt
RCIF
RCIE
Data Bus
8
Stop START
(8) 7 1 0
RX9
• • •
SPBRGLSPBRGH
BRG16
RCIDL
FOSC ÷ n
n
+ 1 Multiplier x4 x16 x64
SYNC 1X00 0
BRGH X110 0
BRG16 X101 0
Baud Rate Generator
2011 Microchip Technology Inc. Preliminary DS41609A-page 239
PIC16(L)F1508/9
22.1 EUSART Asynchronous Mode
The EUSART transmits and receives data using the
standard non-return-to-zero (NRZ) format. NRZ is
implemented with two levels: a VOH mark state which
represents a ‘1’ data bit, and a VOL space state which
represents a ‘0’ data bit. NRZ refers to the fact that
consecutively transmitted data bits of the same value
stay at the output level of that bit without returning to a
neutral level between each bit transmission. An NRZ
transmission port idles in the mark state. Each character
transmission consists of one Start bit followed by eight
or nine data bits and is always terminated by one or
more Stop bits. The Start bit is always a space and the
Stop bits are always marks. The most common data
format is 8 bits. Each transmitted bit persists for a period
of 1/(Baud Rate). An on-chip dedicated 8-bit/16-bit Baud
Rate Generator is used to derive standard baud rate
frequencies from the system oscillator. See Tab le 2 2-5
for examples of baud rate configurations.
The EUSART transmits and receives the LSb first. The
EUSART’s transmitter and receiver are functionally
independent, but share the same data format and baud
rate. Parity is not supported by the hardware, but can
be implemented in software and stored as the ninth
data bit.
22.1.1 EUSART ASYNCHRONOUS
TRANSMITTER
The EUSART transmitter block diagram is shown in
Figure 22-1. The heart of the transmitter is the serial
Transmit Shift Register (TSR), which is not directly
accessible by software. The TSR obtains its data from
the transmit buffer, which is the TXREG register.
22.1.1.1 Enabling the Transmitter
The EUSART transmitter is enabled for asynchronous
operations by configuring the following three control
bits:
•TXEN = 1
• SYNC = 0
• SPEN = 1
All other EUSART control bits are assumed to be in
their default state.
Setting the TXEN bit of the TXSTA register enables the
transmitter circuitry of the EUSART. Clearing the SYNC
bit of the TXSTA register configures the EUSART for
asynchronous operation. Setting the SPEN bit of the
RCSTA register enables the EUSART and automatically
configures the TX/CK I/O pin as an output. If the TX/CK
pin is shared with an analog peripheral, the analog I/O
function must be disabled by clearing the corresponding
ANSEL bit.
22.1.1.2 Transmitting Data
A transmission is initiated by writing a character to the
TXREG register. If this is the first character, or the
previous character has been completely flushed from
the TSR, the data in the TXREG is immediately
transferred to the TSR register. If the TSR still contains
all or part of a previous character, the new character
data is held in the TXREG until the Stop bit of the
previous character has been transmitted. The pending
character in the TXREG is then transferred to the TSR
in one TCY immediately following the Stop bit
transmission. The transmission of the Start bit, data bits
and Stop bit sequence commences immediately
following the transfer of the data to the TSR from the
TXREG.
22.1.1.3 Transmit Data Polarity
The polarity of the transmit data can be controlled with
the SCKP bit of the BAUDCON register. The default
state of this bit is ‘0’ which selects high true transmit idle
and data bits. Setting the SCKP bit to ‘1’ will invert the
transmit data resulting in low true idle and data bits. The
SCKP bit controls transmit data polarity in
Asynchronous mode only. In Synchronous mode, the
SCKP bit has a different function. See Section 22.4.1.2
“Clock Polarity”.
22.1.1.4 Transmit Interrupt Flag
The TXIF interrupt flag bit of the PIR1 register is set
whenever the EUSART transmitter is enabled and no
character is being held for transmission in the TXREG.
In other words, the TXIF bit is only clear when the TSR
is busy with a character and a new character has been
queued for transmission in the TXREG. The TXIF flag bit
is not cleared immediately upon writing TXREG. TXIF
becomes valid in the second instruction cycle following
the write execution. Polling TXIF immediately following
the TXREG write will return invalid results. The TXIF bit
is read-only, it cannot be set or cleared by software.
The TXIF interrupt can be enabled by setting the TXIE
interrupt enable bit of the PIE1 register. However, the
TXIF flag bit will be set whenever the TXREG is empty,
regardless of the state of TXIE enable bit.
To use interrupts when transmitting data, set the TXIE
bit only when there is more data to send. Clear the
TXIE interrupt enable bit upon writing the last character
of the transmission to the TXREG.
Note: The TXIF Transmitter Interrupt flag is set
when the TXEN enable bit is set.
PIC16(L)F1508/9
DS41609A-page 240 Preliminary 2011 Microchip Technology Inc.
22.1.1.5 TSR Status
The TRMT bit of the TXSTA register indicates the
status of the TSR register. This is a read-only bit. The
TRMT bit is set when the TSR register is empty and is
cleared when a character is transferred to the TSR
register from the TXREG. The TRMT bit remains clear
until all bits have been shifted out of the TSR register.
No interrupt logic is tied to this bit, so the user has to
poll this bit to determine the TSR status.
22.1.1.6 Transmitting 9-Bit Characters
The EUSART supports 9-bit character transmissions.
When the TX9 bit of the TXSTA register is set, the
EUSART will shift 9 bits out for each character transmit-
ted. The TX9D bit of the TXSTA register is the ninth,
and Most Significant, data bit. When transmitting 9-bit
data, the TX9D data bit must be written before writing
the 8 Least Significant bits into the TXREG. All nine bits
of data will be transferred to the TSR shift register
immediately after the TXREG is written.
A special 9-bit Address mode is available for use with
multiple receivers. See Section 22.1.2.7 “Address
Detection” for more information on the address mode.
22.1.1.7 Asynchronous Transmission Set-up:
1. Initialize the SPBRGH, SPBRGL register pair and
the BRGH and BRG16 bits to achieve the desired
baud rate (see Section 22.3 “EUSART Baud
Rate Generator (BRG)”).
2. Enable the asynchronous serial port by clearing
the SYNC bit and setting the SPEN bit.
3. If 9-bit transmission is desired, set the TX9 con-
trol bit. A set ninth data bit will indicate that the 8
Least Significant data bits are an address when
the receiver is set for address detection.
4. Set SCKP bit if inverted transmit is desired.
5. Enable the transmission by setting the TXEN
control bit. This will cause the TXIF interrupt bit
to be set.
6. If interrupts are desired, set the TXIE interrupt
enable bit of the PIE1 register. An interrupt will
occur immediately provided that the GIE and
PEIE bits of the INTCON register are also set.
7. If 9-bit transmission is selected, the ninth bit
should be loaded into the TX9D data bit.
8. Load 8-bit data into the TXREG register. This
will start the transmission.
FIGURE 22-3: ASYNCHRONOUS TRANSMISSION
FIGURE 22-4: ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)
Note: The TSR register is not mapped in data
memory, so it is not available to the user.
Word 1
Stop bit
Word 1
Transmit Shift Reg.
Start bit bit 0 bit 1 bit 7/8
Write to TXREG
Word 1
BRG Output
(Shift Clock)
TX/CK
TXIF bit
(Transmit Buffer
Reg. Empty Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
1 TCY
pin
Transmit Shift Reg.
Write to TXREG
BRG Output
(Shift Clock)
TX/CK
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Word 1 Word 2
Word 1 Word 2
Start bit 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
pin
TXIF bit
(Transmit Buffer
Reg. Empty Flag)
2011 Microchip Technology Inc. Preliminary DS41609A-page 241
PIC16(L)F1508/9
TABLE 22-1: SUMMARY OF REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
BAUDCON ABDOVF RCIDL — SCKP BRG16 —WUE ABDEN 248
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IE TMR1IE 79
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 247*
SPBRGL BRG<7:0> 249*
SPBRGH BRG<15:8> 249*
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
TXREG EUSART Transmit Data Register 239
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 246
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used for asynchronous transmission.
* Page provides register information.
PIC16(L)F1508/9
DS41609A-page 242 Preliminary 2011 Microchip Technology Inc.
22.1.2 EUSART ASYNCHRONOUS
RECEIVER
The Asynchronous mode is typically used in RS-232
systems. The receiver block diagram is shown in
Figure 22-2. The data is received on the RX/DT pin and
drives the data recovery block. The data recovery block
is actually a high-speed shifter operating at 16 times
the baud rate, whereas the serial Receive Shift
Register (RSR) operates at the bit rate. When all 8 or 9
bits of the character have been shifted in, they are
immediately transferred to a two character
First-In-First-Out (FIFO) memory. The FIFO buffering
allows reception of two complete characters and the
start of a third character before software must start
servicing the EUSART receiver. The FIFO and RSR
registers are not directly accessible by software.
Access to the received data is via the RCREG register.
22.1.2.1 Enabling the Receiver
The EUSART receiver is enabled for asynchronous
operation by configuring the following three control bits:
• CREN = 1
• SYNC = 0
• SPEN = 1
All other EUSART control bits are assumed to be in
their default state.
Setting the CREN bit of the RCSTA register enables the
receiver circuitry of the EUSART. Clearing the SYNC bit
of the TXSTA register configures the EUSART for
asynchronous operation. Setting the SPEN bit of the
RCSTA register enables the EUSART. The programmer
must set the corresponding TRIS bit to configure the
RX/DT I/O pin as an input.
22.1.2.2 Receiving Data
The receiver data recovery circuit initiates character
reception on the falling edge of the first bit. The first bit,
also known as the Start bit, is always a zero. The data
recovery circuit counts one-half bit time to the center of
the Start bit and verifies that the bit is still a zero. If it is
not a zero then the data recovery circuit aborts
character reception, without generating an error, and
resumes looking for the falling edge of the Start bit. If
the Start bit zero verification succeeds then the data
recovery circuit counts a full bit time to the center of the
next bit. The bit is then sampled by a majority detect
circuit and the resulting ‘0’ or ‘1’ is shifted into the RSR.
This repeats until all data bits have been sampled and
shifted into the RSR. One final bit time is measured and
the level sampled. This is the Stop bit, which is always
a ‘1’. If the data recovery circuit samples a ‘0’ in the
Stop bit position then a framing error is set for this
character, otherwise the framing error is cleared for this
character. See Section 22.1.2.4 “Receive Framing
Error” for more information on framing errors.
Immediately after all data bits and the Stop bit have
been received, the character in the RSR is transferred
to the EUSART receive FIFO and the RCIF interrupt
flag bit of the PIR1 register is set. The top character in
the FIFO is transferred out of the FIFO by reading the
RCREG register.
22.1.2.3 Receive Interrupts
The RCIF interrupt flag bit of the PIR1 register is set
whenever the EUSART receiver is enabled and there is
an unread character in the receive FIFO. The RCIF
interrupt flag bit is read-only, it cannot be set or cleared
by software.
RCIF interrupts are enabled by setting all of the
following bits:
• RCIE interrupt enable bit of the PIE1 register
• PEIE peripheral interrupt enable bit of the
INTCON register
• GIE Global Interrupt Enable bit of the INTCON
register
The RCIF interrupt flag bit will be set when there is an
unread character in the FIFO, regardless of the state of
interrupt enable bits.
Note: If the RX/DT function is on an analog pin,
the corresponding ANSEL bit must be
cleared for the receiver to function.
Note: If the receive FIFO is overrun, no additional
characters will be received until the overrun
condition is cleared. See Section 22.1.2.5
“Receive Overrun Error” for more
information on overrun errors.
2011 Microchip Technology Inc. Preliminary DS41609A-page 243
PIC16(L)F1508/9
22.1.2.4 Receive Framing Error
Each character in the receive FIFO buffer has a
corresponding framing error Status bit. A framing error
indicates that a Stop bit was not seen at the expected
time. The framing error status is accessed via the
FERR bit of the RCSTA register. The FERR bit
represents the status of the top unread character in the
receive FIFO. Therefore, the FERR bit must be read
before reading the RCREG.
The FERR bit is read-only and only applies to the top
unread character in the receive FIFO. A framing error
(FERR = 1) does not preclude reception of additional
characters. It is not necessary to clear the FERR bit.
Reading the next character from the FIFO buffer will
advance the FIFO to the next character and the next
corresponding framing error.
The FERR bit can be forced clear by clearing the SPEN
bit of the RCSTA register which resets the EUSART.
Clearing the CREN bit of the RCSTA register does not
affect the FERR bit. A framing error by itself does not
generate an interrupt.
22.1.2.5 Receive Overrun Error
The receive FIFO buffer can hold two characters. An
overrun error will be generated if a third character, in its
entirety, is received before the FIFO is accessed. When
this happens the OERR bit of the RCSTA register is set.
The characters already in the FIFO buffer can be read
but no additional characters will be received until the
error is cleared. The error must be cleared by either
clearing the CREN bit of the RCSTA register or by
resetting the EUSART by clearing the SPEN bit of the
RCSTA register.
22.1.2.6 Receiving 9-bit Characters
The EUSART supports 9-bit character reception. When
the RX9 bit of the RCSTA register is set the EUSART
will shift 9 bits into the RSR for each character
received. The RX9D bit of the RCSTA register is the
ninth and Most Significant data bit of the top unread
character in the receive FIFO. When reading 9-bit data
from the receive FIFO buffer, the RX9D data bit must
be read before reading the 8 Least Significant bits from
the RCREG.
22.1.2.7 Address Detection
A special Address Detection mode is available for use
when multiple receivers share the same transmission
line, such as in RS-485 systems. Address detection is
enabled by setting the ADDEN bit of the RCSTA
register.
Address detection requires 9-bit character reception.
When address detection is enabled, only characters
with the ninth data bit set will be transferred to the
receive FIFO buffer, thereby setting the RCIF interrupt
bit. All other characters will be ignored.
Upon receiving an address character, user software
determines if the address matches its own. Upon
address match, user software must disable address
detection by clearing the ADDEN bit before the next
Stop bit occurs. When user software detects the end of
the message, determined by the message protocol
used, software places the receiver back into the
Address Detection mode by setting the ADDEN bit.
Note: If all receive characters in the receive
FIFO have framing errors, repeated reads
of the RCREG will not clear the FERR bit.
PIC16(L)F1508/9
DS41609A-page 244 Preliminary 2011 Microchip Technology Inc.
22.1.2.8 Asynchronous Reception Set-up:
1. Initialize the SPBRGH, SPBRGL register pair
and the BRGH and BRG16 bits to achieve the
desired baud rate (see Section 22.3 “EUSART
Baud Rate Generator (BRG)”).
2. Clear the ANSEL bit for the RX pin (if applicable).
3. Enable the serial port by setting the SPEN bit.
The SYNC bit must be clear for asynchronous
operation.
4. If interrupts are desired, set the RCIE bit of the
PIE1 register and the GIE and PEIE bits of the
INTCON register.
5. If 9-bit reception is desired, set the RX9 bit.
6. Enable reception by setting the CREN bit.
7. The RCIF interrupt flag bit will be set when a
character is transferred from the RSR to the
receive buffer. An interrupt will be generated if
the RCIE interrupt enable bit was also set.
8. Read the RCSTA register to get the error flags
and, if 9-bit data reception is enabled, the ninth
data bit.
9. Get the received 8 Least Significant data bits
from the receive buffer by reading the RCREG
register.
10. If an overrun occurred, clear the OERR flag by
clearing the CREN receiver enable bit.
22.1.2.9 9-bit Address Detection Mode Set-up
This mode would typically be used in RS-485 systems.
To set up an Asynchronous Reception with Address
Detect Enable:
1. Initialize the SPBRGH, SPBRGL register pair
and the BRGH and BRG16 bits to achieve the
desired baud rate (see Section 22.3 “EUSART
Baud Rate Generator (BRG)”).
2. Clear the ANSEL bit for the RX pin (if applicable).
3. Enable the serial port by setting the SPEN bit.
The SYNC bit must be clear for asynchronous
operation.
4. If interrupts are desired, set the RCIE bit of the
PIE1 register and the GIE and PEIE bits of the
INTCON register.
5. Enable 9-bit reception by setting the RX9 bit.
6. Enable address detection by setting the ADDEN
bit.
7. Enable reception by setting the CREN bit.
8. The RCIF interrupt flag bit will be set when a
character with the ninth bit set is transferred
from the RSR to the receive buffer. An interrupt
will be generated if the RCIE interrupt enable bit
was also set.
9. Read the RCSTA register to get the error flags.
The ninth data bit will always be set.
10. Get the received 8 Least Significant data bits
from the receive buffer by reading the RCREG
register. Software determines if this is the
device’s address.
11. If an overrun occurred, clear the OERR flag by
clearing the CREN receiver enable bit.
12. If the device has been addressed, clear the
ADDEN bit to allow all received data into the
receive buffer and generate interrupts.
FIGURE 22-5: ASYNCHRONOUS RECEPTION
Start
bit bit 7/8
bit 1bit 0 bit 7/8 bit 0Stop
bit
Start
bit
Start
bit
bit 7/8 Stop
bit
RX/DT pin
Reg
Rcv Buffer Reg.
Rcv Shift
Read Rcv
Buffer Reg.
RCREG
RCIF
(Interrupt Flag)
OERR bit
CREN
Word 1
RCREG
Word 2
RCREG
Stop
bit
Note: This timing diagram shows three words appearing on the RX input. The RCREG (receive buffer) is read after the third word,
causing the OERR (overrun) bit to be set.
RCIDL
2011 Microchip Technology Inc. Preliminary DS41609A-page 245
PIC16(L)F1508/9
TABLE 22-2: SUMMARY OF REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
BAUDCON ABDOVF RCIDL —SCKP BRG16 —WUEABDEN 248
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IE TMR1IE 79
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
RCREG EUSART Receive Data Register 242*
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 247*
SPBRGL BRG<7:0> 249*
SPBRGH BRG<15:8> 249*
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 246
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used for asynchronous reception.
* Page provides register information.
PIC16(L)F1508/9
DS41609A-page 246 Preliminary 2011 Microchip Technology Inc.
22.2 Clock Accuracy with
Asynchronous Operation
The factory calibrates the internal oscillator block out-
put (INTOSC). However, the INTOSC frequency may
drift as VDD or temperature changes, and this directly
affects the asynchronous baud rate. Two methods may
be used to adjust the baud rate clock, but both require
a reference clock source of some kind.
The first (preferred) method uses the OSCTUNE
register to adjust the INTOSC output. Adjusting the
value in the OSCTUNE register allows for fine resolution
changes to the system clock source. See Section 5.2.2
“Internal Clock Sources” for more information.
The other method adjusts the value in the Baud Rate
Generator. This can be done automatically with the
Auto-Baud Detect feature (see Section 22.3.1
“Auto-Baud Detect”). There may not be fine enough
resolution when adjusting the Baud Rate Generator to
compensate for a gradual change in the peripheral
clock frequency.
REGISTER 22-1: TXSTA: TRANSMIT STATUS AND CONTROL REGISTER
R/W-/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R-1/1 R/W-0/0
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’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
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: Ninth bit of Transmit Data
Can be address/data bit or a parity bit.
Note 1: SREN/CREN overrides TXEN in Sync mode.
2011 Microchip Technology Inc. Preliminary DS41609A-page 247
PIC16(L)F1508/9
REGISTER 22-2: RCSTA: RECEIVE STATUS AND CONTROL REGISTER(1)
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R-0/0 R-0/0 R-0/0
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’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 SPEN: Serial Port Enable bit
1 = Serial port enabled (configures RX/DT and TX/CK 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, enable interrupt and load 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 8-bit (RX9 = 0):
Don’t care
bit 2 FERR: Framing Error bit
1 = Framing error (can be updated by reading RCREG register and receive 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: Ninth bit of Received Data
This can be address/data bit or a parity bit and must be calculated by user firmware.
PIC16(L)F1508/9
DS41609A-page 248 Preliminary 2011 Microchip Technology Inc.
REGISTER 22-3: BAUDCON: BAUD RATE CONTROL REGISTER
R-0/0 R-1/1 U-0 R/W-0/0 R/W-0/0 U-0 R/W-0/0 R/W-0/0
ABDOVF RCIDL — SCKP BRG16 — WUE ABDEN
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 ABDOVF: Auto-Baud Detect Overflow bit
Asynchronous mode:
1 = Auto-baud timer overflowed
0 = Auto-baud timer did not overflow
Synchronous mode:
Don’t care
bit 6 RCIDL: Receive Idle Flag bit
Asynchronous mode:
1 = Receiver is idle
0 = Start bit has been received and the receiver is receiving
Synchronous mode:
Don’t care
bit 5 Unimplemented: Read as ‘0’
bit 4 SCKP: Synchronous Clock Polarity Select bit
Asynchronous mode:
1 = Transmit inverted data to the TX/CK pin
0 = Transmit non-inverted data to the TX/CK pin
Synchronous mode:
1 = Data is clocked on rising edge of the clock
0 = Data is clocked on falling edge of the clock
bit 3 BRG16: 16-bit Baud Rate Generator bit
1 = 16-bit Baud Rate Generator is used
0 = 8-bit Baud Rate Generator is used
bit 2 Unimplemented: Read as ‘0’
bit 1 WUE: Wake-up Enable bit
Asynchronous mode:
1 = Receiver is waiting for a falling edge. No character will be received, byte RCIF will be set. WUE
will automatically clear after RCIF is set.
0 = Receiver is operating normally
Synchronous mode:
Don’t care
bit 0 ABDEN: Auto-Baud Detect Enable bit
Asynchronous mode:
1 = Auto-Baud Detect mode is enabled (clears when auto-baud is complete)
0 = Auto-Baud Detect mode is disabled
Synchronous mode:
Don’t care
2011 Microchip Technology Inc. Preliminary DS41609A-page 249
PIC16(L)F1508/9
22.3 EUSART Baud Rate Generator
(BRG)
The Baud Rate Generator (BRG) is an 8-bit or 16-bit
timer that is dedicated to the support of both the
asynchronous and synchronous EUSART operation.
By default, the BRG operates in 8-bit mode. Setting the
BRG16 bit of the BAUDCON register selects 16-bit
mode.
The SPBRGH, SPBRGL register pair determines the
period of the free running baud rate timer. In
Asynchronous mode the multiplier of the baud rate
period is determined by both the BRGH bit of the TXSTA
register and the BRG16 bit of the BAUDCON register. In
Synchronous mode, the BRGH bit is ignored.
Table 22-3 contains the formulas for determining the
baud rate. Example 22-1 provides a sample calculation
for determining the baud rate and baud rate error.
Typical baud rates and error values for various
Asynchronous modes have been computed for your
convenience and are shown in Table 22-3. It may be
advantageous to use the high baud rate (BRGH = 1),
or the 16-bit BRG (BRG16 = 1) to reduce the baud rate
error. The 16-bit BRG mode is used to achieve slow
baud rates for fast oscillator frequencies.
Writing a new value to the SPBRGH, SPBRGL register
pair causes the BRG timer to be reset (or cleared). This
ensures that the BRG does not wait for a timer overflow
before outputting the new baud rate.
If the system clock is changed during an active receive
operation, a receive error or data loss may result. To
avoid this problem, check the status of the RCIDL bit to
make sure that the receive operation is idle before
changing the system clock.
EXAMPLE 22-1: CALCULATING BAUD
RATE ERROR
For a device with FOSC of 16 MHz, desired baud rate
of 9600, Asynchronous mode, 8-bit BRG:
Solving for SPBRGH:SPBRGL:
X
FOSC
Desired Baud Rate
---------------------------------------------
64
--------------------------------------------- 1–=
Desired Baud Rate FOSC
64 [SPBRGH:SPBRGL] 1+
------------------------------------------------------------------------=
16000000
9600
------------------------
64
------------------------1–=
25.04225==
Calculated Baud Rate 16000000
64 25 1+
---------------------------=
9615=
Error Calc. Baud Rate Desired Baud Rate –
Desired Baud Rate
--------------------------------------------------------------------------------------------=
9615 9600–
9600
---------------------------------- 0 . 1 6 %==
PIC16(L)F1508/9
DS41609A-page 250 Preliminary 2011 Microchip Technology Inc.
TABLE 22-3: BAUD RATE FORMULAS
TABLE 22-4: SUMMARY OF REGISTERS ASSOCIATED WITH THE BAUD RATE GENERATOR
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 SPBRGH, SPBRGL register pair.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
BAUDCON ABDOVF RCIDL —SCKP BRG16 —WUE ABDEN 248
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 247
SPBRGL BRG<7:0> 249*
SPBRGH BRG<15:8> 249*
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 246
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used for the Baud Rate Generator.
* Page provides register information.
2011 Microchip Technology Inc. Preliminary DS41609A-page 251
PIC16(L)F1508/9
TABLE 22-5: BAUD RATES FOR ASYNCHRONOUS MODES
BAUD
RATE
SYNC = 0, BRGH = 0, BRG16 = 0
FOSC = 20.000 MHz FOSC = 18.432 MHz FOSC = 16.000 MHz FOSC = 11.0592 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
300—— — —— — —— — —— —
1200 1221 1.73 255 1200 0.00 239 1202 0.16 207 1200 0.00 143
2400 2404 0.16 129 2400 0.00 119 2404 0.16 103 2400 0.00 71
9600 9470 -1.36 32 9600 0.00 29 9615 0.16 25 9600 0.00 17
10417 10417 0.00 29 10286 -1.26 27 10417 0.00 23 10165 -2.42 16
19.2k 19.53k 1.73 15 19.20k 0.00 14 19.23k 0.16 12 19.20k 0.00 8
57.6k — — — 57.60k 0.00 7—
—— 57.60k 0.00 2
115.2k — — — — — — — — — — — —
BAUD
RATE
SYNC = 0, BRGH = 0, BRG16 = 0
FOSC = 8.000 MHz FOSC = 4.000 MHz FOSC = 3.6864 MHz FOSC = 1.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
300 — — — 300 0.16 207 300 0.00 191 300 0.16 51
1200 1202 0.16 103 1202 0.16 51 1200 0.00 47 1202 0.16 12
2400 2404 0.16 51 2404 0.16 25 2400 0.00 23 — — —
9600 9615 0.16 12 — — — 9600 0.00 5 — — —
10417 10417 0.00 11 10417 0.00 5 — — — — — —
19.2k — — — — — — 19.20k 0.00 2 — — —
57.6k — — — — — — 57.60k 0.00 0 — — —
115.2k — — — — — — — — — — — —
BAUD
RATE
SYNC = 0, BRGH = 1, BRG16 = 0
FOSC = 20.000 MHz FOSC = 18.432 MHz FOSC = 16.000 MHz FOSC = 11.0592 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
300 —— — —— — —— — —— —
1200 — — — — — — — — — — — —
2400 — — — — — — — — — —— —
9600 9615 0.16 129 9600 0.00 119 9615 0.16 103 9600 0.00 71
10417 10417 0.00 119 10378 -0.37 110 10417 0.00 95 10473 0.53 65
19.2k 19.23k 0.16 64 19.20k 0.00 59 19.23k 0.16 51 19.20k 0.00 35
57.6k 56.82k -1.36 21 57.60k 0.00 19 58.82k 2.12 16 57.60k 0.00 11
115.2k 113.64k -1.36 10 115.2k 0.00 9 111.1k -3.55 8 115.2k 0.00 5
PIC16(L)F1508/9
DS41609A-page 252 Preliminary 2011 Microchip Technology Inc.
BAUD
RATE
SYNC = 0, BRGH = 1, BRG16 = 0
FOSC = 8.000 MHz FOSC = 4.000 MHz FOSC = 3.6864 MHz FOSC = 1.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
300 —— — — — — — — — 300 0.16 207
1200 — — — 1202 0.16 207 1200 0.00 191 1202 0.16 51
2400 2404 0.16 207 2404 0.16 103 2400 0.00 95 2404 0.16 25
9600 9615 0.16 51 9615 0.16 25 9600 0.00 23 — — —
10417 10417 0.00 47 10417 0.00 23 10473 0.53 21 10417 0.00 5
19.2k 19231 0.16 25 19.23k 0.16 12 19.2k 0.00 11 — — —
57.6k 55556 -3.55 8 — — — 57.60k 0.00 3 — — —
115.2k — — — — — — 115.2k 0.00 1 — — —
BAUD
RATE
SYNC = 0, BRGH = 0, BRG16 = 1
FOSC = 20.000 MHz FOSC = 18.432 MHz FOSC = 16.000 MHz FOSC = 11.0592 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
300 300.0 -0.01 4166 300.0 0.00 3839 300.03 0.01 3332 300.0 0.00 2303
1200 1200 -0.03 1041 1200 0.00 959 1200.5 0.04 832 1200 0.00 575
2400 2399 -0.03 520 2400 0.00 479 2398 -0.08 416 2400 0.00 287
9600 9615 0.16 129 9600 0.00 119 9615 0.16 103 9600 0.00 71
10417 10417 0.00 119 10378 -0.37 110 10417 0.00 95 10473 0.53 65
19.2k 19.23k 0.16 64 19.20k 0.00 59 19.23k 0.16 51 19.20k 0.00 35
57.6k 56.818 -1.36 21 57.60k 0.00 19 58.82k 2.12 16 57.60k 0.00 11
115.2k 113.636 -1.36 10 115.2k 0.00 9 111.11k -3.55 8 115.2k 0.00 5
BAUD
RATE
SYNC = 0, BRGH = 0, BRG16 = 1
FOSC = 8.000 MHz FOSC = 4.000 MHz FOSC = 3.6864 MHz FOSC = 1.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
300 299.9 -0.02 1666 300.1 0.04 832 300.0 0.00 767 300.5 0.16 207
1200 1199 -0.08 416 1202 0.16 207 1200 0.00 191 1202 0.16 51
2400 2404 0.16 207 2404 0.16 103 2400 0.00 95 2404 0.16 25
9600 9615 0.16 51 9615 0.16 25 9600 0.00 23 — — —
10417 10417 0.00 47 10417 0.00 23 10473 0.53 21 10417 0.00 5
19.2k 19.23k 0.16 25 19.23k 0.16 12 19.20k 0.00 11 — — —
57.6k 55556 -3.55 8 — — — 57.60k 0.00 3 — — —
115.2k — — — — — — 115.2k 0.00 1 — — —
TABLE 22-5: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)
2011 Microchip Technology Inc. Preliminary DS41609A-page 253
PIC16(L)F1508/9
BAUD
RATE
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
FOSC = 20.000 MHz FOSC = 18.432 MHz FOSC = 16.000 MHz FOSC = 11.0592 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
300 300.0 0.00 16665 300.0 0.00 15359 300.0 0.00 13332 300.0 0.00 9215
1200 1200 -0.01 4166 1200 0.00 3839 1200.1 0.01 3332 1200 0.00 2303
2400 2400 0.02 2082 2400 0.00 1919 2399.5 -0.02 1666 2400 0.00 1151
9600 9597 -0.03 520 9600 0.00 479 9592 -0.08 416 9600 0.00 287
10417 10417 0.00 479 10425 0.08 441 10417 0.00 383 10433 0.16 264
19.2k 19.23k 0.16 259 19.20k 0.00 239 19.23k 0.16 207 19.20k 0.00 143
57.6k 57.47k -0.22 86 57.60k 0.00 79 57.97k 0.64 68 57.60k 0.00 47
115.2k 116.3k 0.94 42 115.2k 0.00 39 114.29k -0.79 34 115.2k 0.00 23
BAUD
RATE
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
FOSC = 8.000 MHz FOSC = 4.000 MHz FOSC = 3.6864 MHz FOSC = 1.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
300 300.0 0.00 6666 300.0 0.01 3332 300.0 0.00 3071 300.1 0.04 832
1200 1200 -0.02 1666 1200 0.04 832 1200 0.00 767 1202 0.16 207
2400 2401 0.04 832 2398 0.08 416 2400 0.00 383 2404 0.16 103
9600 9615 0.16 207 9615 0.16 103 9600 0.00 95 9615 0.16 25
10417 10417 0 191 10417 0.00 95 10473 0.53 87 10417 0.00 23
19.2k 19.23k 0.16 103 19.23k 0.16 51 19.20k 0.00 47 19.23k 0.16 12
57.6k 57.14k -0.79 34 58.82k 2.12 16 57.60k 0.00 15 — — —
115.2k 117.6k 2.12 16 111.1k -3.55 8 115.2k 0.00 7 — — —
TABLE 22-5: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)
PIC16(L)F1508/9
DS41609A-page 254 Preliminary 2011 Microchip Technology Inc.
22.3.1 AUTO-BAUD DETECT
The EUSART module supports automatic detection
and calibration of the baud rate.
In the Auto-Baud Detect (ABD) mode, the clock to the
BRG is reversed. Rather than the BRG clocking the
incoming RX signal, the RX signal is timing the BRG.
The Baud Rate Generator is used to time the period of
a received 55h (ASCII “U”) which is the Sync character
for the LIN bus. The unique feature of this character is
that it has five rising edges including the Stop bit edge.
Setting the ABDEN bit of the BAUDCON register starts
the auto-baud calibration sequence (Figure 22-6).
While the ABD sequence takes place, the EUSART
state machine is held in Idle. On the first rising edge of
the receive line, after the Start bit, the SPBRG begins
counting up using the BRG counter clock as shown in
Table 22-6. The fifth rising edge will occur on the RX pin
at the end of the eighth bit period. At that time, an
accumulated value totaling the proper BRG period is
left in the SPBRGH, SPBRGL register pair, the ABDEN
bit is automatically cleared and the RCIF interrupt flag
is set. The value in the RCREG needs to be read to
clear the RCIF interrupt. RCREG content should be
discarded. When calibrating for modes that do not use
the SPBRGH register the user can verify that the
SPBRGL register did not overflow by checking for 00h
in the SPBRGH register.
The BRG auto-baud clock is determined by the BRG16
and BRGH bits as shown in Table 22-6. During ABD,
both the SPBRGH and SPBRGL registers are used as
a 16-bit counter, independent of the BRG16 bit setting.
While calibrating the baud rate period, the SPBRGH
and SPBRGL registers are clocked at 1/8th the BRG
base clock rate. The resulting byte measurement is the
average bit time when clocked at full speed.
TABLE 22-6: BRG COUNTER CLOCK RATES
FIGURE 22-6: AUTOMATIC BAUD RATE CALIBRATION
Note 1: If the WUE bit is set with the ABDEN bit,
auto-baud detection will occur on the byte
following the Break character (see
Section 22.3.3 “Auto-Wake-up on
Break”).
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.
3: During the auto-baud process, the
auto-baud counter starts counting at 1.
Upon completion of the auto-baud
sequence, to achieve maximum accuracy,
subtract 1 from the SPBRGH:SPBRGL
register pair.
BRG16 BRGH BRG Base
Clock
BRG ABD
Clock
00FOSC/64 FOSC/512
01FOSC/16 FOSC/128
10FOSC/16 FOSC/128
11 FOSC/4 FOSC/32
Note: During the ABD sequence, SPBRGL and
SPBRGH registers are both used as a 16-bit
counter, independent of BRG16 setting.
BRG Value
RX pin
ABDEN bit
RCIF bit
bit 0 bit 1
(Interrupt)
Read
RCREG
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
Stop bit
Edge #5
001Ch
Note 1: The ABD sequence requires the EUSART module to be configured in Asynchronous mode.
SPBRGL XXh 1Ch
SPBRGH XXh 00h
RCIDL
2011 Microchip Technology Inc. Preliminary DS41609A-page 255
PIC16(L)F1508/9
22.3.2 AUTO-BAUD OVERFLOW
During the course of automatic baud detection, the
ABDOVF bit of the BAUDCON register will be set if the
baud rate counter overflows before the fifth rising edge
is detected on the RX pin. The ABDOVF bit indicates
that the counter has exceeded the maximum count that
can fit in the 16 bits of the SPBRGH:SPBRGL register
pair. After the ABDOVF bit has been set, the counter
continues to count until the fifth rising edge is detected
on the RX pin. Upon detecting the fifth RX edge, the
hardware will set the RCIF interrupt flag and clear the
ABDEN bit of the BAUDCON register. The RCIF flag
can be subsequently cleared by reading the RCREG
register. The ABDOVF flag of the BAUDCON register
can be cleared by software directly.
To terminate the auto-baud process before the RCIF
flag is set, clear the ABDEN bit then clear the ABDOVF
bit of the BAUDCON register. The ABDOVF bit will
remain set if the ABDEN bit is not cleared first.
22.3.3 AUTO-WAKE-UP ON BREAK
During Sleep mode, all clocks to the EUSART are
suspended. Because of this, the Baud Rate Generator
is inactive and a proper character reception cannot be
performed. The Auto-Wake-up feature allows the
controller to wake-up due to activity on the RX/DT line.
This feature is available only in Asynchronous mode.
The Auto-Wake-up feature is enabled by setting the
WUE bit of the BAUDCON register. Once set, the normal
receive sequence on RX/DT 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
RX/DT line. (This coincides with the start of a Sync Break
or a wake-up signal character for the LIN protocol.)
The EUSART module generates an RCIF interrupt
coincident with the wake-up event. The interrupt is
generated synchronously to the Q clocks in normal CPU
operating modes (Figure 22-7), and asynchronously if
the device is in Sleep mode (Figure 22-8). The interrupt
condition is cleared by reading the RCREG register.
The WUE bit is automatically cleared by the low-to-high
transition on the RX line at the end of the Break. This
signals to the user that the Break event is over. At this
point, the EUSART module is in Idle mode waiting to
receive the next character.
22.3.3.1 Special Considerations
Break Character
To avoid character errors or character fragments during
a wake-up event, the wake-up character must be all
zeros.
When the wake-up is enabled the function works
independent of the low time on the data stream. If the
WUE bit is set and a valid non-zero character is
received, the low time from the Start bit to the first rising
edge will be interpreted as the wake-up event. The
remaining bits in the character will be received as a
fragmented character and subsequent characters can
result in framing or overrun errors.
Therefore, the initial character in the transmission must
be all ‘0’s. This must be 10 or more bit times, 13-bit
times recommended for LIN bus, or any number of bit
times for standard RS-232 devices.
Oscillator Start-up Time
Oscillator start-up time must be considered, especially
in applications using oscillators with longer start-up
intervals (i.e., LP, XT or HS/PLL 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.
WUE Bit
The wake-up event causes a receive interrupt by
setting the RCIF bit. The WUE bit is cleared in
hardware by a rising edge on RX/DT. The interrupt
condition is then cleared in software by reading the
RCREG register and discarding its contents.
To ensure that no actual data is lost, check the RCIDL
bit to verify that a receive operation is not in process
before setting the WUE bit. If a receive operation is not
occurring, the WUE bit may then be set just prior to
entering the Sleep mode.
PIC16(L)F1508/9
DS41609A-page 256 Preliminary 2011 Microchip Technology Inc.
FIGURE 22-7: AUTO-WAKE-UP BIT (WUE) TIMING DURING NORMAL OPERATION
FIGURE 22-8: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
WUE bit
RX/DT Line
RCIF
Bit set by user Auto Cleared
Cleared due to User Read of RCREG
Note 1: The EUSART remains in Idle while the WUE bit is set.
Q1Q2 Q3 Q4 Q1Q2 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
RX/DT Line
RCIF
Bit Set by User Auto Cleared
Cleared due to User Read of RCREG
Sleep Command Executed
Note 1
Note 1: If the wake-up event requires long oscillator warm-up time, the automatic clearing of the WUE bit can occur while the stposc signal is
still active. 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
2011 Microchip Technology Inc. Preliminary DS41609A-page 257
PIC16(L)F1508/9
22.3.4 BREAK CHARACTER SEQUENCE
The EUSART module has the capability of sending the
special Break character sequences that are required by
the LIN bus standard. A Break character consists of a
Start bit, followed by 12 ‘0’ bits and a Stop bit.
To send a Break character, set the SENDB and TXEN
bits of the TXSTA register. The Break character trans-
mission is then initiated by a write to the TXREG. The
value of data written to TXREG will be ignored and all
‘0’s 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).
The TRMT bit of the TXSTA register indicates when the
transmit operation is active or idle, just as it does during
normal transmission. See Figure 22-9 for the timing of
the Break character sequence.
22.3.4.1 Break and Sync Transmit Sequence
The following sequence will start 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 enable the
Break sequence.
3. Load the TXREG with a dummy character to
initiate transmission (the value is ignored).
4. Write ‘55h’ to TXREG to load the Sync character
into the transmit FIFO buffer.
5. After the Break has been sent, the SENDB bit is
reset by hardware and the Sync character is
then transmitted.
When the TXREG becomes empty, as indicated by the
TXIF, the next data byte can be written to TXREG.
22.3.5 RECEIVING A BREAK CHARACTER
The Enhanced EUSART module can receive a Break
character in two ways.
The first method to detect a Break character uses the
FERR bit of the RCSTA register and the Received data
as indicated by RCREG. The Baud Rate Generator is
assumed to have been initialized to the expected baud
rate.
A Break character has been received when;
• RCIF bit is set
• FERR bit is set
• RCREG = 00h
The second method uses the Auto-Wake-up feature
described in Section 22.3.3 “Auto-Wake-up on
Break”. By enabling this feature, the EUSART will
sample the next two transitions on RX/DT, cause an
RCIF 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 Detect feature.
For both methods, the user can set the ABDEN bit of
the BAUDCON register before placing the EUSART in
Sleep mode.
FIGURE 22-9: SEND BREAK CHARACTER SEQUENCE
Write to TXREG Dummy Write
BRG Output
(Shift Clock)
Start bit bit 0 bit 1 bit 11 Stop bit
Break
TXIF bit
(Transmit
Interrupt Flag)
TX (pin)
TRMT bit
(Transmit Shift
Empty Flag)
SENDB
(send Break
control bit)
SENDB Sampled Here Auto Cleared
PIC16(L)F1508/9
DS41609A-page 258 Preliminary 2011 Microchip Technology Inc.
22.4 EUSART Synchronous Mode
Synchronous serial communications are typically used
in systems with a single master and one or more
slaves. The master device contains the necessary cir-
cuitry for baud rate generation and supplies the clock
for all devices in the system. Slave devices can take
advantage of the master clock by eliminating the inter-
nal clock generation circuitry.
There are two signal lines in Synchronous mode: a bidi-
rectional data line and a clock line. Slaves use the
external clock supplied by the master to shift the serial
data into and out of their respective receive and trans-
mit shift registers. Since the data line is bidirectional,
synchronous operation is half-duplex only. Half-duplex
refers to the fact that master and slave devices can
receive and transmit data but not both simultaneously.
The EUSART can operate as either a master or slave
device.
Start and Stop bits are not used in synchronous trans-
missions.
22.4.1 SYNCHRONOUS MASTER MODE
The following bits are used to configure the EUSART
for synchronous master operation:
• SYNC = 1
• CSRC = 1
• SREN = 0 (for transmit); SREN = 1 (for receive)
• CREN = 0 (for transmit); CREN = 1 (for receive)
• SPEN = 1
Setting the SYNC bit of the TXSTA register configures
the device for synchronous operation. Setting the CSRC
bit of the TXSTA register configures the device as a
master. Clearing the SREN and CREN bits of the RCSTA
register ensures that the device is in the Transmit mode,
otherwise the device will be configured to receive. Setting
the SPEN bit of the RCSTA register enables the
EUSART.
22.4.1.1 Master Clock
Synchronous data transfers use a separate clock line,
which is synchronous with the data. A device config-
ured as a master transmits the clock on the TX/CK line.
The TX/CK pin output driver is automatically enabled
when the EUSART is configured for synchronous
transmit or receive operation. Serial data bits change
on the leading edge to ensure they are valid at the trail-
ing edge of each clock. One clock cycle is generated
for each data bit. Only as many clock cycles are gener-
ated as there are data bits.
22.4.1.2 Clock Polarity
A clock polarity option is provided for Microwire
compatibility. Clock polarity is selected with the SCKP
bit of the BAUDCON register. Setting the SCKP bit sets
the clock Idle state as high. When the SCKP bit is set,
the data changes on the falling edge of each clock.
Clearing the SCKP bit sets the Idle state as low. When
the SCKP bit is cleared, the data changes on the rising
edge of each clock.
22.4.1.3 Synchronous Master Transmission
Data is transferred out of the device on the RX/DT pin.
The RX/DT and TX/CK pin output drivers are automat-
ically enabled when the EUSART is configured for syn-
chronous master transmit operation.
A transmission is initiated by writing a character to the
TXREG register. If the TSR still contains all or part of a
previous character the new character data is held in the
TXREG until the last bit of the previous character has
been transmitted. If this is the first character, or the pre-
vious character has been completely flushed from the
TSR, the data in the TXREG is immediately transferred
to the TSR. The transmission of the character com-
mences immediately following the transfer of the data
to the TSR from the TXREG.
Each data bit changes on the leading edge of the mas-
ter clock and remains valid until the subsequent leading
clock edge.
22.4.1.4 Synchronous Master Transmission
Set-up:
1. Initialize the SPBRGH, SPBRGL register pair
and the BRGH and BRG16 bits to achieve the
desired baud rate (see Section 22.3 “EUSART
Baud Rate Generator (BRG)”).
2. Enable the synchronous master serial port by
setting bits SYNC, SPEN and CSRC.
3. Disable Receive mode by clearing bits SREN
and CREN.
4. Enable Transmit mode by setting the TXEN bit.
5. If 9-bit transmission is desired, set the TX9 bit.
6. If interrupts are desired, set the TXIE bit of the
PIE1 register and the GIE and PEIE bits of the
INTCON register.
7. If 9-bit transmission is selected, the ninth bit
should be loaded in the TX9D bit.
8. Start transmission by loading data to the TXREG
register.
Note: The TSR register is not mapped in data
memory, so it is not available to the user.
2011 Microchip Technology Inc. Preliminary DS41609A-page 259
PIC16(L)F1508/9
FIGURE 22-10: SYNCHRONOUS TRANSMISSION
FIGURE 22-11: SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
TABLE 22-7: SUMMARY OF REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER
TRANSMISSION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
BAUDCON ABDOVF RCIDL — SCKP BRG16 —WUE ABDEN 248
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IE TMR1IE 79
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 247
SPBRGL BRG<7:0> 249*
SPBRGH BRG<15:8> 249*
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
TXREG EUSART Transmit Data Register 239*
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 246
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used for synchronous master transmission.
* Page provides register information.
bit 0 bit 1 bit 7
Word 1
bit 2 bit 0 bit 1 bit 7
RX/DT
Write to
TXREG Reg
TXIF bit
(Interrupt Flag)
TXEN bit ‘1’ ‘1’
Word 2
TRMT bit
Write Word 1 Write Word 2
Note: Sync Master mode, SPBRGL = 0, continuous transmission of two 8-bit words.
pin
TX/CK pin
TX/CK pin
(SCKP = 0)
(SCKP = 1)
RX/DT pin
TX/CK pin
Write to
TXREG reg
TXIF bit
TRMT bit
bit 0 bit 1 bit 2 bit 6 bit 7
TXEN bit
PIC16(L)F1508/9
DS41609A-page 260 Preliminary 2011 Microchip Technology Inc.
22.4.1.5 Synchronous Master Reception
Data is received at the RX/DT pin. The RX/DT pin
output driver is automatically disabled when the
EUSART is configured for synchronous master receive
operation.
In Synchronous mode, reception is enabled by setting
either the Single Receive Enable bit (SREN of the
RCSTA register) or the Continuous Receive Enable bit
(CREN of the RCSTA register).
When SREN is set and CREN is clear, only as many
clock cycles are generated as there are data bits in a
single character. The SREN bit is automatically cleared
at the completion of one character. When CREN is set,
clocks are continuously generated until CREN is
cleared. If CREN is cleared in the middle of a character
the CK clock stops immediately and the partial charac-
ter is discarded. If SREN and CREN are both set, then
SREN is cleared at the completion of the first character
and CREN takes precedence.
To initiate reception, set either SREN or CREN. Data is
sampled at the RX/DT pin on the trailing edge of the
TX/CK clock pin and is shifted into the Receive Shift
Register (RSR). When a complete character is
received into the RSR, the RCIF bit is set and the char-
acter is automatically transferred to the two character
receive FIFO. The Least Significant eight bits of the top
character in the receive FIFO are available in RCREG.
The RCIF bit remains set as long as there are unread
characters in the receive FIFO.
22.4.1.6 Slave Clock
Synchronous data transfers use a separate clock line,
which is synchronous with the data. A device configured
as a slave receives the clock on the TX/CK line. The
TX/CK pin output driver is automatically disabled when
the device is configured for synchronous slave transmit
or receive operation. Serial data bits change on the
leading edge to ensure they are valid at the trailing edge
of each clock. One data bit is transferred for each clock
cycle. Only as many clock cycles should be received as
there are data bits.
22.4.1.7 Receive Overrun Error
The receive FIFO buffer can hold two characters. An
overrun error will be generated if a third character, in its
entirety, is received before RCREG is read to access
the FIFO. When this happens the OERR bit of the
RCSTA register is set. Previous data in the FIFO will
not be overwritten. The two characters in the FIFO
buffer can be read, however, no additional characters
will be received until the error is cleared. The OERR bit
can only be cleared by clearing the overrun condition.
If the overrun error occurred when the SREN bit is set
and CREN is clear then the error is cleared by reading
RCREG. If the overrun occurred when the CREN bit is
set then the error condition is cleared by either clearing
the CREN bit of the RCSTA register or by clearing the
SPEN bit which resets the EUSART.
22.4.1.8 Receiving 9-bit Characters
The EUSART supports 9-bit character reception. When
the RX9 bit of the RCSTA register is set the EUSART
will shift 9-bits into the RSR for each character
received. The RX9D bit of the RCSTA register is the
ninth, and Most Significant, data bit of the top unread
character in the receive FIFO. When reading 9-bit data
from the receive FIFO buffer, the RX9D data bit must
be read before reading the 8 Least Significant bits from
the RCREG.
22.4.1.9 Synchronous Master Reception
Set-up:
1. Initialize the SPBRGH, SPBRGL register pair for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
2. Clear the ANSEL bit for the RX pin (if applicable).
3. Enable the synchronous master serial port by
setting bits SYNC, SPEN and CSRC.
4. Ensure bits CREN and SREN are clear.
5. If interrupts are desired, set the RCIE bit of the
PIE1 register and the GIE and PEIE bits of the
INTCON register.
6. If 9-bit reception is desired, set bit RX9.
7. Start reception by setting the SREN bit or for
continuous reception, set the CREN bit.
8. Interrupt flag bit RCIF will be set when reception
of a character is complete. An interrupt will be
generated if the enable bit RCIE was set.
9. Read the RCSTA register to get the ninth bit (if
enabled) and determine if any error occurred
during reception.
10. Read the 8-bit received data by reading the
RCREG register.
11. If an overrun error occurs, clear the error by
either clearing the CREN bit of the RCSTA
register or by clearing the SPEN bit which resets
the EUSART.
Note: If the RX/DT function is on an analog pin,
the corresponding ANSEL bit must be
cleared for the receiver to function.
Note: If the device is configured as a slave and
the TX/CK function is on an analog pin, the
corresponding ANSEL bit must be
cleared.
2011 Microchip Technology Inc. Preliminary DS41609A-page 261
PIC16(L)F1508/9
FIGURE 22-12: SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
TABLE 22-8: SUMMARY OF REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER
RECEPTION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
BAUDCON ABDOVF RCIDL — SCKP BRG16 —WUE ABDEN 248
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IE TMR1IE 79
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
RCREG EUSART Receive Data Register 242*
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 247
SPBRGL BRG<7:0> 249*
SPBRGH BRG<15:8> 249*
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 246
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used for synchronous master reception.
* Page provides register information.
CREN bit
RX/DT
Write to
bit SREN
SREN bit
RCIF bit
(Interrupt)
Read
RCREG
‘0’
bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7
‘0’
Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRGH = 0.
TX/CK pin
TX/CK pin
pin
(SCKP = 0)
(SCKP = 1)
PIC16(L)F1508/9
DS41609A-page 262 Preliminary 2011 Microchip Technology Inc.
22.4.2 SYNCHRONOUS SLAVE MODE
The following bits are used to configure the EUSART
for synchronous slave operation:
• SYNC = 1
• CSRC = 0
• SREN = 0 (for transmit); SREN = 1 (for receive)
• CREN = 0 (for transmit); CREN = 1 (for receive)
• SPEN = 1
Setting the SYNC bit of the TXSTA register configures the
device for synchronous operation. Clearing the CSRC bit
of the TXSTA register configures the device as a slave.
Clearing the SREN and CREN bits of the RCSTA register
ensures that the device is in the Transmit mode,
otherwise the device will be configured to receive. Setting
the SPEN bit of the RCSTA register enables the
EUSART.
22.4.2.1 EUSART Synchronous Slave
Transmit
The operation of the Synchronous Master and Slave
modes are identical (see Section 22.4.1.3
“Synchronous Master Transmission”), except in the
case of the Sleep mode.
If two words are written to the TXREG and then the
SLEEP instruction is executed, the following will occur:
1. The first character will immediately transfer to
the TSR register and transmit.
2. The second word will remain in the TXREG
register.
3. The TXIF bit will not be set.
4. After the first character has been shifted out of
TSR, the TXREG register will transfer the second
character to the TSR and the TXIF bit will now be
set.
5. If the PEIE and TXIE bits are set, the interrupt
will wake the device from Sleep and execute the
next instruction. If the GIE bit is also set, the
program will call the Interrupt Service Routine.
22.4.2.2 Synchronous Slave Transmission
Set-up:
1. Set the SYNC and SPEN bits and clear the
CSRC bit.
2. Clear the ANSEL bit for the CK pin (if applicable).
3. Clear the CREN and SREN bits.
4. If interrupts are desired, set the TXIE bit of the
PIE1 register and the GIE and PEIE bits of the
INTCON register.
5. If 9-bit transmission is desired, set the TX9 bit.
6. Enable transmission by setting the TXEN bit.
7. If 9-bit transmission is selected, insert the Most
Significant bit into the TX9D bit.
8. Start transmission by writing the Least
Significant 8 bits to the TXREG register.
TABLE 22-9: SUMMARY OF REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE
TRANSMISSION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
BAUDCON ABDOVF RCIDL —SCKPBRG16 —WUE ABDEN 248
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IE TMR1IE 79
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 247
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
TXREG EUSART Transmit Data Register 239*
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 246
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used for synchronous slave transmission.
* Page provides register information.
2011 Microchip Technology Inc. Preliminary DS41609A-page 263
PIC16(L)F1508/9
22.4.2.3 EUSART Synchronous Slave
Reception
The operation of the Synchronous Master and Slave
modes is identical (Section 22.4.1.5 “Synchronous
Master Reception”), with the following exceptions:
• Sleep
• CREN bit is always set, therefore the receiver is
never idle
• SREN bit, which is a “don’t care” in Slave mode
A character may be received while in Sleep mode by
setting the CREN bit prior to entering Sleep. Once the
word is received, the RSR register will transfer the data
to the RCREG register. If the RCIE enable bit is set, the
interrupt generated will wake the device from Sleep
and execute the next instruction. If the GIE bit is also
set, the program will branch to the interrupt vector.
22.4.2.4 Synchronous Slave Reception
Set-up:
1. Set the SYNC and SPEN bits and clear the
CSRC bit.
2. Clear the ANSEL bit for both the CK and DT pins
(if applicable).
3. If interrupts are desired, set the RCIE bit of the
PIE1 register and the GIE and PEIE bits of the
INTCON register.
4. If 9-bit reception is desired, set the RX9 bit.
5. Set the CREN bit to enable reception.
6. The RCIF bit will be set when reception is
complete. An interrupt will be generated if the
RCIE bit was set.
7. If 9-bit mode is enabled, retrieve the Most
Significant bit from the RX9D bit of the RCSTA
register.
8. Retrieve the 8 Least Significant bits from the
receive FIFO by reading the RCREG register.
9. If an overrun error occurs, clear the error by
either clearing the CREN bit of the RCSTA
register or by clearing the SPEN bit which resets
the EUSART.
TABLE 22-10: SUMMARY OF REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE
RECEPTION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
BAUDCON ABDOVF RCIDL —SCKPBRG16 —WUE ABDEN 248
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE1 TMR1GIE ADIE RCIE TXIE SSP1IE —TMR2IE TMR1IE 79
PIR1 TMR1GIF ADIF RCIF TXIF SSP1IF —TMR2IF TMR1IF 82
RCREG EUSART Receive Data Register 242*
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 247
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 246
Legend: — = unimplemented location, read as ‘0’. Shaded cells are not used for synchronous slave reception.
* Page provides register information.
PIC16(L)F1508/9
DS41609A-page 264 Preliminary 2011 Microchip Technology Inc.
22.5 EUSART Operation During Sleep
The EUSART will remain active during Sleep only in the
Synchronous Slave mode. All other modes require the
system clock and therefore cannot generate the neces-
sary signals to run the Transmit or Receive Shift regis-
ters during Sleep.
Synchronous Slave mode uses an externally generated
clock to run the Transmit and Receive Shift registers.
22.5.1 SYNCHRONOUS RECEIVE DURING
SLEEP
To receive during Sleep, all the following conditions
must be met before entering Sleep mode:
• RCSTA and TXSTA Control registers must be
configured for Synchronous Slave Reception (see
Section 22.4.2.4 “Synchronous Slave
Reception Set-up:”).
• If interrupts are desired, set the RCIE bit of the
PIE1 register and the GIE and PEIE bits of the
INTCON register.
• The RCIF interrupt flag must be cleared by read-
ing RCREG to unload any pending characters in
the receive buffer.
Upon entering Sleep mode, the device will be ready to
accept data and clocks on the RX/DT and TX/CK pins,
respectively. When the data word has been completely
clocked in by the external device, the RCIF interrupt
flag bit of the PIR1 register will be set. Thereby, waking
the processor from Sleep.
Upon waking from Sleep, the instruction following the
SLEEP instruction will be executed. If the Global Inter-
rupt Enable (GIE) bit of the INTCON register is also set,
then the Interrupt Service Routine at address 004h will
be called.
22.5.2 SYNCHRONOUS TRANSMIT
DURING SLEEP
To transmit during Sleep, all the following conditions
must be met before entering Sleep mode:
• RCSTA and TXSTA Control registers must be
configured for synchronous slave transmission
(see Section 22.4.2.2 “Synchronous Slave
Transmission Set-up:”).
• The TXIF interrupt flag must be cleared by writing
the output data to the TXREG, thereby filling the
TSR and transmit buffer.
• If interrupts are desired, set the TXIE bit of the
PIE1 register and the PEIE bit of the INTCON reg-
ister.
• Interrupt enable bits TXIE of the PIE1 register and
PEIE of the INTCON register must set.
Upon entering Sleep mode, the device will be ready to
accept clocks on TX/CK pin and transmit data on the
RX/DT pin. When the data word in the TSR has been
completely clocked out by the external device, the
pending byte in the TXREG will transfer to the TSR and
the TXIF flag will be set. Thereby, waking the processor
from Sleep. At this point, the TXREG is available to
accept another character for transmission, which will
clear the TXIF flag.
Upon waking from Sleep, the instruction following the
SLEEP instruction will be executed. If the Global
Interrupt Enable (GIE) bit is also set then the Interrupt
Service Routine at address 0004h will be called.
22.5.3 ALTERNATE PIN LOCATIONS
This module incorporates I/O pins that can be moved to
other locations with the use of the alternate pin function
register, APFCON. To determine which pins can be
moved and what their default locations are upon a
Reset, see Section 11.1 “Alternate Pin Function” for
more information.
2011 Microchip Technology Inc. Preliminary DS41609A-page 265
PIC16(L)F1508/9
23.0 PULSE WIDTH MODULATION
(PWM) MODULE
The PWM module generates a Pulse-Width Modulated
signal determined by the duty cycle, period, and reso-
lution that are configured by the following registers:
•PR2
•T2CON
• PWMxDCH
• PWMxDCL
•PWMxCON
Figure 23-2 shows a simplified block diagram of PWM
operation.
Figure 23-1 shows a typical waveform of the PWM
signal.
For a step-by-step procedure on how to set up this
module for PWM operation, refer to Section 23.1.9
“Setup for PWM Operation using PWMx Pins”.
FIGURE 23-1: PWM OUTPUT
FIGURE 23-2: SIMPLIFIED PWM BLOCK DIAGRAM
Period
Pulse Width
TMR2 = 0
TMR2 =
TMR2 = PR2
PWMxDCH<7:0>:PWMxDCL<7:6>
PWMxDCH
Comparator
TMR2
Comparator
PR2
(1)
RQ
S
Duty Cycle registers PWMxDCL<7:6>
Clear Timer,
PWMx pin and
latch Duty Cycle
Note 1: 8-bit timer is concatenated with the two Least Significant bits of 1/FOSC adjusted by
the Timer2 prescaler to create a 10-bit time base.
Latched
(Not visible to user)
Q
Output Polarity (PWMxPOL)
TMR2 Module
0
1
PWMxOUT
to other peripherals: CLC and CWG
PWMx
Output Enable (PWMxOE)
TRIS Control
PIC16(L)F1508/9
DS41609A-page 266 Preliminary 2011 Microchip Technology Inc.
23.1 PWMx Pin Configuration
All PWM outputs are multiplexed with the PORT data
latch. The user must configure the pins as outputs by
clearing the associated TRIS bits.
23.1.1 FUNDAMENTAL OPERATION
The PWM module produces a 10-bit resolution output.
Timer2 and PR2 set the period of the PWM. The
PWMxDCL and PWMxDCH registers configure the
duty cycle. The period is common to all PWM modules,
whereas the duty cycle is independently controlled.
All PWM outputs associated with Timer2 are set when
TMR2 is cleared. Each PWMx is cleared when TMR2
is equal to the value specified in the corresponding
PWMxDCH (8 MSb) and PWMxDCL<7:6> (2 LSb) reg-
isters. When the value is greater than or equal to PR2,
the PWM output is never cleared (100% duty cycle).
23.1.2 PWM OUTPUT POLARITY
The output polarity is inverted by setting the PWMxPOL
bit of the PWMxCON register.
23.1.3 PWM PERIOD
The PWM period is specified by the PR2 register of
Timer2. The PWM period can be calculated using the
formula of Equation 23-1.
EQUATION 23-1: PWM PERIOD
When TMR2 is equal to PR2, the following three events
occur on the next increment cycle:
•TMR2 is cleared
• The PWM output is active. (Exception: When the
PWM duty cycle = 0%, the PWM output will
remain inactive.)
• The PWMxDCH and PWMxDCL register values
are latched into the buffers.
23.1.4 PWM DUTY CYCLE
The PWM duty cycle is specified by writing a 10-bit
value to the PWMxDCH and PWMxDCL register pair.
The PWMxDCH register contains the eight MSbs and
the PWMxDCL<7:6>, the two LSbs. The PWMxDCH
and PWMxDCL registers can be written to at any time.
Equation 23-2 is used to calculate the PWM pulse
width.
Equation 23-3 is used to calculate the PWM duty cycle
ratio.
EQUATION 23-2: PULSE WIDTH
EQUATION 23-3: DUTY CYCLE RATIO
The 8-bit timer TMR2 register is concatenated with the
two Least Significant bits of 1/FOSC, adjusted by the
Timer2 prescaler to create the 10-bit time base. The
system clock is used if the Timer2 prescaler is set to
1:1.
Note: Clearing the PWMxOE bit will relinquish
control of the PWMx pin.
Note: The Timer2 postscaler 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.
Note: The PWMxDCH and PWMxDCL registers
are double buffered. The buffers are
updated when Timer2 matches PR2. Care
should be taken to update both registers
before the timer match occurs.
PWM Period PR21+4TOSC =
(TMR2 Prescale Value)
Note: TOSC = 1/FOSC
Note: The Timer2 postscaler has no effect on
the PWM operation.
Pulse Width PWM xDCH:PWMxDCL<7:6>
=
TOSC
(TMR2 Prescale Value)
Note: TOSC = 1/FOSC
Duty Cycle Ratio PWMxDCH:PWMxDCL<7:6>
4 PR2 1+
-----------------------------------------------------------------------------------=
2011 Microchip Technology Inc. Preliminary DS41609A-page 267
PIC16(L)F1508/9
23.1.5 PWM RESOLUTION
The resolution determines the number of available duty
cycles for a given period. For example, a 10-bit resolu-
tion will result in 1024 discrete duty cycles, whereas an
8-bit resolution will result in 256 discrete duty cycles.
The maximum PWM resolution is 10 bits when PR2 is
255. The resolution is a function of the PR2 register
value as shown by Equation 23-4.
EQUATION 23-4: PWM RESOLUTION
23.1.6 OPERATION IN SLEEP MODE
In Sleep mode, the TMR2 register will not increment
and the state of the module will not change. If the
PWMx pin is driving a value, it will continue to drive that
value. When the device wakes up, TMR2 will continue
from its previous state.
23.1.7 CHANGES IN SYSTEM CLOCK
FREQUENCY
The PWM frequency is derived from the system clock
frequency (FOSC). Any changes in the system clock fre-
quency will result in changes to the PWM frequency.
Refer to Section 5.0 “Oscillator Module (With
Fail-Safe Clock Monitor)” for additional details.
23.1.8 EFFECTS OF RESET
Any Reset will force all ports to Input mode and the
PWM registers to their Reset states.
Note: If the pulse width value is greater than the
period the assigned PWM pin(s) will
remain unchanged.
Resolution 4PR2 1+log
2log
------------------------------------------ bits=
TABLE 23-1: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS (FOSC = 20 MHz)
PWM Frequency 0.31 kHz 4.88 kHz 19.53 kHz 78.12 kHz 156.3 kHz 208.3 kHz
Timer Prescale (1, 4, 64) 64 4 1 1 1 1
PR2 Value 0xFF 0xFF 0xFF 0x3F 0x1F 0x17
Maximum Resolution (bits) 10 10 10 8 7 6.6
TABLE 23-2: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS (FOSC = 8 MHz)
PWM Frequency 0.31 kHz 4.90 kHz 19.61 kHz 76.92 kHz 153.85 kHz 200.0 kHz
Timer Prescale (1, 4, 64) 64 4 1 1 1 1
PR2 Value 0x65 0x65 0x65 0x19 0x0C 0x09
Maximum Resolution (bits) 8 8 8 6 5 5
PIC16(L)F1508/9
DS41609A-page 268 Preliminary 2011 Microchip Technology Inc.
23.1.9 SETUP FOR PWM OPERATION
USING PWMx PINS
The following steps should be taken when configuring
the module for PWM operation using the PWMx pins:
1. Disable the PWMx pin output driver(s) by setting
the associated TRIS bit(s).
2. Clear the PWMxCON register.
3. Load the PR2 register with the PWM period
value.
4. Clear the PWMxDCH register and bits <7:6> of
the PWMxDCL register.
5. Configure and start Timer2:
• Clear the TMR2IF interrupt flag bit of the
PIR1 register. See Note below.
• Configure the T2CKPS bits of the T2CON
register with the Timer2 prescale value.
• Enable Timer2 by setting the TMR2ON bit of
the T2CON register.
6. Enable PWM output pin and wait until Timer2
overflows, TMR2IF bit of the PIR1 register is set.
See note below.
7. Enable the PWMx pin output driver(s) by clear-
ing the associated TRIS bit(s) and setting the
PWMxOE bit of the PWMxCON register.
8. Configure the PWM module by loading the
PWMxCON register with the appropriate values.
Note 1: In order to send a complete duty cycle
and period on the first PWM output, the
above steps must be followed in the order
given. If it is not critical to start with a
complete PWM signal, then move Step 8
to replace Step 4.
2: For operation with other peripherals only,
disable PWMx pin outputs.
2011 Microchip Technology Inc. Preliminary DS41609A-page 269
PIC16(L)F1508/9
23.2 PWM Register Definitions
REGISTER 23-1: PWMxCON: PWM CONTROL REGISTER
R/W-0/0 R/W-0/0 R-0/0 R/W-0/0 U-0 U-0 U-0 U-0
PWMxEN PWMxOE PWMxOUT PWMxPOL — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 PWMxEN: PWM Module Enable bit
1 = PWM module is enabled
0 = PWM module is disabled
bit 6 PWMxOE: PWM Module Output Enable bit
1 = Output to PWMx pin is enabled
0 = Output to PWMx pin is disabled
bit 5 PWMxOUT: PWM Module Output Value bit
bit 4 PWMxPOL: PWMx Output Polarity Select bit
1 = PWM output is active low
0 = PWM output is active high
bit 3-0 Unimplemented: Read as ‘0’
PIC16(L)F1508/9
DS41609A-page 270 Preliminary 2011 Microchip Technology Inc.
REGISTER 23-2: PWMxDCH: PWM DUTY CYCLE HIGH BITS
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
PWMxDCH<7:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 PWMxDCH<7:0>: PWM Duty Cycle Most Significant bits
These bits are the MSbs of the PWM duty cycle. The two LSbs are found in the PWMxDCL register.
REGISTER 23-3: PWMxDCL: PWM DUTY CYCLE LOW BITS
R/W-x/u R/W-x/u U-0 U-0 U-0 U-0 U-0 U-0
PWMxDCL<7:6> — — — — — —
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-6 PWMxDCL<7:6>: PWM Duty Cycle Least Significant bits
These bits are the LSbs of the PWM duty cycle. The MSbs are found in the PWMxDCH register.
bit 5-0 Unimplemented: Read as ‘0’
TABLE 23-3: SUMMARY OF REGISTERS ASSOCIATED WITH PWM
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
PR2 Timer2 module Period Register 179*
PWM1CON PWM1EN PWM1OE PWM1OUT PWM1POL — — — — 269
PWM1DCH PWM1DCH<7:0> 270
PWM1DCL PWM1DCL<7:6> — — — — — — 270
PWM2CON PWM2EN PWM2OE PWM2OUT PWM2POL — — — — 270
PWM2DCH PWM2DCH<7:0> 270
PWM2DCL PWM2DCL<7:6> — — — — — — 270
PWM3CON PWM3EN PWM3OE PWM3OUT PWM3POL — — — — 269
PWM3DCH PWM3DCH<7:0> 270
PWM3DCL PWM3DCL<7:6> — — — — — — 270
PWM4CON PWM4EN PWM4OE PWM4OUT PWM4POL — — — — 269
PWM4DCH PWM4DCH<7:0> 270
PWM4DCL PWM4DCL<7:6> — — — — — — 270
T2CON —T2OUTPS<3:0> TMR2ON T2CKPS<1:0> 181
TMR2 Timer2 module Register 179*
TRISA — — TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
Legend: - = Unimplemented locations, read as ‘0’, u = unchanged, x = unknown. Shaded cells are not used by the PWM.
* Page provides register information.
Note 1: Unimplemented, read as ‘1’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 271
PIC16(L)F1508/9
24.0 CONFIGURABLE LOGIC CELL
(CLC)
The Configurable Logic Cell (CLCx) provides program-
mable logic that operates outside the speed limitations
of software execution. The logic cell takes up to 16
input signals and through the use of configurable gates
reduces the 16 inputs to four logic lines that drive one
of eight selectable single-output logic functions.
Input sources are a combination of the following:
• I/O pins
• Internal clocks
• Peripherals
• Register bits
The output can be directed internally to peripherals and
to an output pin.
Refer to Figure 24-1 for a simplified diagram showing
signal flow through the CLCx.
Possible configurations include:
• Combinatorial Logic
-AND
-NAND
- AND-OR
- AND-OR-INVERT
-OR-XOR
-OR-XNOR
• Latches
-S-R
- Clocked D with Set and Reset
- Transparent D with Set and Reset
- Clocked J-K with Reset
FIGURE 24-1: CLCx SIMPLIFIED BLOCK DIAGRAM
lcxg1
lcxg2
lcxg3
lcxg4
Interrupt
det
Logic
Function
Input Data Selection Gates
CLCx
LCxOE
lcxq
LCxPOL
LCxOUT
DQ
LE
Q1
LCxMODE<2:0>
lcx_out
CLCxIN[0]
CLCxIN[1]
CLCxIN[2]
CLCxIN[3]
CLCxIN[4]
CLCxIN[5]
CLCxIN[6]
CLCxIN[7]
CLCxIN[8]
CLCxIN[9]
CLCxIN[10]
CLCxIN[11]
CLCxIN[12]
CLCxIN[13]
CLCxIN[14]
CLCxIN[15]
TRIS Control
Interrupt
det
LCxINTP
LCxINTN
MLCxOUT
LCxEN
CLCxIF
sets
flag
See Figure 24-3
See Figure 24-2
PIC16(L)F1508/9
DS41609A-page 272 Preliminary 2011 Microchip Technology Inc.
24.1 CLCx Setup
Programming the CLCx module is performed by config-
uring the 4 stages in the logic signal flow. The 4 stages
are:
•Data selection
• Data gating
• Logic function selection
• Output polarity
Each stage is setup at run time by writing to the corre-
sponding CLCx Special Function Registers. This has
the added advantage of permitting logic reconfiguration
on-the-fly during program execution.
24.1.1 DATA SELECTION
There are 16 signals available as inputs to the configu-
rable logic. Four 8-input multiplexers are used to select
the inputs to pass on to the next stage. The 16 inputs to
the multiplexers are arranged in groups of four. Each
group is available to two of the four multiplexers, in
each case, paired with a different group. This arrange-
ment makes possible selection of up to two from a
group without precluding a selection from another
group.
Data inputs are selected with the CLCxSEL0 and
CLCxSEL1 registers (Register 24-3 and Register 24-4,
respectively).
Data inputs are selected with CLCxSEL0 and
CLCxSEL1 registers (Register 24-3 and Register 24-4,
respectively).
Data selection is through four multiplexers as indicated
on the left side of Figure 24-2. Data inputs in the figure
are identified by a generic numbered input name.
Table 24-1 correlates the generic input name to the
actual signal for each CLC module. The columns labeled
lcxd1 through lcxd4 indicate the MUX output for the
selected data input. D1S through D4S are abbreviations
for the MUX select input codes: LCxD1S<2:0> through
LCxD4S<2:0>, respectively. Selecting a data input in a
column excludes all other inputs in that column.
Note: Data selections are undefined at power-up.
TABLE 24-1: CLCx DATA INPUT SELECTION
Data Input lcxd1
D1S
lcxd2
D2S
lcxd3
D3S
lcxd4
D4S CLC 1CLC 2CLC 3CLC 4
CLCxIN[0] 000 — — 100 CLC1IN0 CLC2IN0 CLC3IN0 CLC4IN0
CLCxIN[1] 001 — — 101 CLC1IN1 CLC2IN1 CLC3IN1 CLC4IN1
CLCxIN[2] 010 — — 110 SYNCC1OUT SYNCC1OUT SYNCC1OUT SYNCC1OUT
CLCxIN[3] 011 — — 111 SYNCC2OUT SYNCC2OUT SYNCC2OUT SYNCC2OUT
CLCxIN[4] 100 000 ——FOSC FOSC FOSC FOSC
CLCxIN[5] 101 001 —— TMR0IF TMR0IF TMR0IF TMR0IF
CLCxIN[6] 110 010 —— TMR1IF TMR1IF TMR1IF TMR1IF
CLCxIN[7] 111 011 —— TMR2 = PR2 TMR2 = PR2 TMR2 = PR2 TMR2 = PR2
CLCxIN[8] —100 000 — lc1_out lc1_out lc1_out lc1_out
CLCxIN[9] —101 001 — lc2_out lc2_out lc2_out lc2_out
CLCxIN[10] —110 010 — lc3_out lc3_out lc3_out lc3_out
CLCxIN[11] —111 011 — lc4_out lc4_out lc4_out lc4_out
CLCxIN[12] — — 100 000 NCO1OUT LFINTOSC TX (EUSART) SCK (MSSP)
CLCxIN[13] — — 101 001 HFINTOSC ADFRC LFINTOSC SDO (MSSP)
CLCxIN[14] — — 110 010 PWM3OUT PWM1OUT PWM2OUT PWM1OUT
CLCxIN[15] — — 111 011 PWM4OUT PWM2OUT PWM3OUT PWM4OUT
2011 Microchip Technology Inc. Preliminary DS41609A-page 273
PIC16(L)F1508/9
24.1.2 DATA GATING
Outputs from the input multiplexers are directed to the
desired logic function input through the data gating
stage. Each data gate can direct any combination of the
four selected inputs.
The gate stage is more than just signal direction. The
gate can be configured to direct each input signal as
inverted or non-inverted data. Directed signals are
ANDed together in each gate. The output of each gate
can be inverted before going on to the logic function
stage.
The gating is in essence a 1-to-4 input
AND/NAND/OR/NOR gate. When every input is
inverted and the output is inverted, the gate is an OR of
all enabled data inputs. When the inputs and output are
not inverted, the gate is an AND or all enabled inputs.
Table 24-2 summarizes the basic logic that can be
obtained in gate 1 by using the gate logic select bits.
The table shows the logic of four input variables, but
each gate can be configured to use less than four. If
no inputs are selected, the output will be zero or one,
depending on the gate output polarity bit.
It is possible (but not recommended) to select both the
true and negated values of an input. When this is done,
the gate output is zero, regardless of the other inputs,
but may emit logic glitches (transient-induced pulses).
If the output of the channel must be zero or one, the
recommended method is to set all gate bits to zero and
use the gate polarity bit to set the desired level.
Data gating is configured with the logic gate select reg-
isters as follows:
• Gate 1: CLCxGLS0 (Register 24-5)
• Gate 2: CLCxGLS1 (Register 24-6)
• Gate 3: CLCxGLS2 (Register 24-7)
• Gate 4: CLCxGLS3 (Register 24-8)
Register number suffixes are different than the gate
numbers because other variations of this module have
multiple gate selections in the same register.
Data gating is indicated in the right side of Figure 24-2.
Only one gate is shown in detail. The remaining three
gates are configured identically with the exception that
the data enables correspond to the enables for that
gate.
24.1.3 LOGIC FUNCTION
There are 8 available logic functions including:
• AND-OR
•OR-XOR
•AND
• S-R Latch
• D Flip-Flop with Set and Reset
• D Flip-Flop with Reset
• J-K Flip-Flop with Reset
• Transparent Latch with Set and Reset
Logic functions are shown in Figure 24-3. Each logic
function has four inputs and one output. The four inputs
are the four data gate outputs of the previous stage.
The output is fed to the inversion stage and from there
to other peripherals, an output pin, and back to the
CLCx itself.
24.1.4 OUTPUT POLARITY
The last stage in the configurable logic cell is the output
polarity. Setting the LCxPOL bit of the CLCxCON reg-
ister inverts the output signal from the logic stage.
Changing the polarity while the interrupts are enabled
will cause an interrupt for the resulting output transition.
Note: Data gating is undefined at power-up.
TABLE 24-2: DATA GATING LOGIC
CLCxGLS0 LCxG1POL Gate Logic
0x55 1AND
0x55 0NAND
0xAA 1NOR
0xAA 0OR
0x00 0Logic 0
0x00 1Logic 1
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DS41609A-page 274 Preliminary 2011 Microchip Technology Inc.
24.1.5 CLCx SETUP STEPS
The following steps should be followed when setting up
the CLCx:
• Disable CLCx by clearing the LCxEN bit.
• Select desired inputs using CLCxSEL0 and
CLCxSEL1 registers (See Table 24-1).
• Clear any associated ANSEL bits.
• Set all TRIS bits associated with inputs.
• Clear all TRIS bits associated with outputs.
• Enable the chosen inputs through the four gates
using CLCxGLS0, CLCxGLS1, CLCxGLS2, and
CLCxGLS3 registers.
• Select the gate output polarities with the
LCxPOLy bits of the CLCxPOL register.
• Select the desired logic function with the
LCxMODE<2:0> bits of the CLCxCON register.
• Select the desired polarity of the logic output with
the LCxPOL bit of the CLCxPOL register. (This
step may be combined with the previous gate out-
put polarity step).
• If driving the CLCx pin, set the LCxOE bit of the
CLCxCON register and also clear the TRIS bit
corresponding to that output.
• If interrupts are desired, configure the following
bits:
- Set the LCxINTP bit in the CLCxCON register
for rising event.
- Set the LCxINTN bit in the CLCxCON
register or falling event.
- Set the CLCxIE bit of the associated PIE
registers.
- Set the GIE and PEIE bits of the INTCON
register.
• Enable the CLCx by setting the LCxEN bit of the
CLCxCON register.
24.2 CLCx Interrupts
An interrupt will be generated upon a change in the
output value of the CLCx when the appropriate interrupt
enables are set. A rising edge detector and a falling
edge detector are present in each CLC for this purpose.
The CLCxIF bit of the associated PIR registers will be
set when either edge detector is triggered and its asso-
ciated enable bit is set. The LCxINTP enables rising
edge interrupts and the LCxINTN bit enables falling
edge interrupts. Both are located in the CLCxCON reg-
ister.
To fully enable the interrupt, set the following bits:
• LCxON bit of the CLCxCON register
• CLCxIE bit of the associated PIE registers
• LCxINTP bit of the CLCxCON register (for a rising
edge detection)
• LCxINTN bit of the CLCxCON register (for a fall-
ing edge detection)
• PEIE and GIE bits of the INTCON register
The CLCxIF bit of the associated PIR registers, must
be cleared in software as part of the interrupt service. If
another edge is detected while this flag is being
cleared, the flag will still be set at the end of the
sequence.
24.3 Output Mirror Copies
Mirror copies of all LCxCON output bits are contained
in the CLCxDATA register. Reading this register reads
the outputs of all CLCs simultaneously. This prevents
any reading skew introduced by testing or reading the
CLCxOUT bits in the individual CLCxCON registers.
24.4 Effects of a Reset
The CLCxCON register is cleared to zero as the result
of a Reset. All other selection and gating values remain
unchanged.
24.5 Operation During Sleep
The CLC module operates independently from the
system clock and will continue to run during Sleep,
provided that the input sources selected remain active.
The HFINTOSC remains active during Sleep when the
CLC module is enabled and the HFINTOSC is
selected as an input source, regardless of the system
clock source selected.
In other words, if the HFINTOSC is simultaneously
selected as the system clock and as a CLC input
source, when the CLC is enabled, the CPU will go idle
during Sleep, but the CLC will continue to operate and
the HFINTOSC will remain active.
This will have a direct effect on the Sleep mode current.
2011 Microchip Technology Inc. Preliminary DS41609A-page 275
PIC16(L)F1508/9
FIGURE 24-2: INPUT DATA SELECTION AND GATING
lcxg1
LCxG1POL
Data GATE 1
LCxD1G1T
lcxg2
lcxg3
lcxg4
Data GATE 2
Data GATE 3
Data GATE 4
LCxD1G1N
LCxD2G1T
LCxD2G1N
LCxD3G1T
LCxD3G1N
LCxD4G1T
LCxD4G1N
LCxD1S<2:0>
LCxD2S<2:0>
LCxD3S<2:0>
LCxD4S<2:0>
CLCxIN[0]
CLCxIN[1]
CLCxIN[2]
CLCxIN[3]
CLCxIN[4]
CLCxIN[5]
CLCxIN[6]
CLCxIN[7]
000
111
000
111
000
111
000
111
CLCxIN[4]
CLCxIN[5]
CLCxIN[6]
CLCxIN[7]
CLCxIN[8]
CLCxIN[9]
CLCxIN[10]
CLCxIN[11]
CLCxIN[8]
CLCxIN[9]
CLCxIN[10]
CLCxIN[11]
CLCxIN[12]
CLCxIN[13]
CLCxIN[14]
CLCxIN[15]
CLCxIN[12]
CLCxIN[13]
CLCxIN[14]
CLCxIN[15]
CLCxIN[0]
CLCxIN[1]
CLCxIN[2]
CLCxIN[3]
Data Selection
Note: All controls are undefined at power-up.
lcxd1T
lcxd1N
lcxd2T
lcxd2N
lcxd3T
lcxd3N
lcxd4T
lcxd4N
(Same as Data GATE 1)
(Same as Data GATE 1)
(Same as Data GATE 1)
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DS41609A-page 276 Preliminary 2011 Microchip Technology Inc.
FIGURE 24-3: PROGRAMMABLE LOGIC FUNCTIONS
lcxg1
lcxg2
lcxg3
lcxg4
lcxq
lcxg1
lcxg2
lcxg3
lcxg4
lcxq
lcxg1
lcxg2
lcxg3
lcxg4
lcxq
S
R
Q
lcxg1
lcxg2
lcxg3
lcxg4
lcxq
DQ
lcxg1
lcxg2
lcxg3
lcxg4
lcxq
S
R
JQ
lcxg2
lcxg3
lcxg4
lcxq
R
lcxg1
K
DQ
lcxg1
lcxg2
lcxg3
lcxg4
lcxq
S
R
DQ
lcxg1
lcxg3
lcxq
R
lcxg4
lcxg2
LCxMODE<2:0>= 000
LCxMODE<2:0>= 010
LCxMODE<2:0>= 001
LCxMODE<2:0>= 011
LCxMODE<2:0>= 100
LCxMODE<2:0>= 110
LCxMODE<2:0>= 101
LCxMODE<2:0>= 111
LE
AND – OR OR – XOR
4-Input AND S-R Latch
1-Input D Flip-Flop with S and R 2-Input D Flip-Flop with R
1-Input Transparent Latch with S and R
J-K Flip-Flop with R
2011 Microchip Technology Inc. Preliminary DS41609A-page 277
PIC16(L)F1508/9
24.6 CLCx Control Registers
REGISTER 24-1: CLCxCON: CONFIGURABLE LOGIC CELL CONTROL REGISTER
R/W-0/0 R/W-0/0 R-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
LCxEN LCxOE LCxOUT LCxINTP LCxINTN LCxMODE<2:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 LCxEN: Configurable Logic Cell Enable bit
1 = Configurable logic cell is enabled and mixing input signals
0 = Configurable logic cell is disabled and has logic zero output
bit 6 LCxOE: Configurable Logic Cell Output Enable bit
1 = Configurable logic cell port pin output enabled
0 = Configurable logic cell port pin output disabled
bit 5 LCxOUT: Configurable Logic Cell Data Output bit
Read-only: logic cell output data, after LCxPOL; sampled from lcx_out wire.
bit 4 LCxINTP: Configurable Logic Cell Positive Edge Going Interrupt Enable bit
1 = CLCxIF will be set when a rising edge occurs on lcx_out
0 = CLCxIF will not be set
bit 3 LCxINTN: Configurable Logic Cell Negative Edge Going Interrupt Enable bit
1 = CLCxIF will be set when a falling edge occurs on lcx_out
0 = CLCxIF will not be set
bit 2-0 LCxMODE<2:0>: Configurable Logic Cell Functional Mode bits
111 = Cell is 1-input transparent latch with S and R
110 = Cell is J-K flip-flop with R
101 = Cell is 2-input D flip-flop with R
100 = Cell is 1-input D flip-flop with S and R
011 = Cell is S-R latch
010 = Cell is 4-input AND
001 = Cell is OR-XOR
000 = Cell is AND-OR
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DS41609A-page 278 Preliminary 2011 Microchip Technology Inc.
REGISTER 24-2: CLCxPOL: SIGNAL POLARITY CONTROL REGISTER
R/W-0/0 U-0 U-0 U-0 R/W-x/u R/W-x/u R/W-x/u R/W-x/u
LCxPOL — — — LCxG4POL LCxG3POL LCxG2POL LCxG1POL
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 LCxPOL: LCOUT Polarity Control bit
1 = The output of the logic cell is inverted
0 = The output of the logic cell is not inverted
bit 6-4 Unimplemented: Read as ‘0’
bit 3 LCxG4POL: Gate 4 Output Polarity Control bit
1 = The output of gate 4 is inverted when applied to the logic cell
0 = The output of gate 4 is not inverted
bit 2 LCxG3POL: Gate 3 Output Polarity Control bit
1 = The output of gate 3 is inverted when applied to the logic cell
0 = The output of gate 3 is not inverted
bit 1 LCxG2POL: Gate 2 Output Polarity Control bit
1 = The output of gate 2 is inverted when applied to the logic cell
0 = The output of gate 2 is not inverted
bit 0 LCxG1POL: Gate 1 Output Polarity Control bit
1 = The output of gate 1 is inverted when applied to the logic cell
0 = The output of gate 1 is not inverted
2011 Microchip Technology Inc. Preliminary DS41609A-page 279
PIC16(L)F1508/9
REGISTER 24-3: CLCxSEL0: MULTIPLEXER DATA 1 AND 2 SELECT REGISTER
U-0 R/W-x/u R/W-x/u R/W-x/u U-0 R/W-x/u R/W-x/u R/W-x/u
— LCxD2S<2:0> — LCxD1S<2:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 Unimplemented: Read as ‘0’
bit 6-4 LCxD2S<2:0>: Input Data 2 Selection Control bits(1)
111 = CLCxIN[11] is selected for lcxd2
110 = CLCxIN[10] is selected for lcxd2
101 = CLCxIN[9] is selected for lcxd2
100 = CLCxIN[8] is selected for lcxd2
011 = CLCxIN[7] is selected for lcxd2
010 = CLCxIN[6] is selected for lcxd2
001 = CLCxIN[5] is selected for lcxd2
000 = CLCxIN[4] is selected for lcxd2
bit 3 Unimplemented: Read as ‘0’
bit 2-0 LCxD1S<2:0>: Input Data 1 Selection Control bits(1)
111 = CLCxIN[7] is selected for lcxd1
110 = CLCxIN[6] is selected for lcxd1
101 = CLCxIN[5] is selected for lcxd1
100 = CLCxIN[4] is selected for lcxd1
011 = CLCxIN[3] is selected for lcxd1
010 = CLCxIN[2] is selected for lcxd1
001 = CLCxIN[1] is selected for lcxd1
000 = CLCxIN[0] is selected for lcxd1
Note 1: See Table 24-1 for signal names associated with inputs.
PIC16(L)F1508/9
DS41609A-page 280 Preliminary 2011 Microchip Technology Inc.
REGISTER 24-4: CLCxSEL1: MULTIPLEXER DATA 3 AND 4 SELECT REGISTER
U-0 R/W-x/u R/W-x/u R/W-x/u U-0 R/W-x/u R/W-x/u R/W-x/u
— LCxD4S<2:0> — LCxD3S<2:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 Unimplemented: Read as ‘0’
bit 6-4 LCxD4S<2:0>: Input Data 4 Selection Control bits(1)
111 = CLCxIN[3] is selected for lcxd4
110 = CLCxIN[2] is selected for lcxd4
101 = CLCxIN[1] is selected for lcxd4
100 = CLCxIN[0] is selected for lcxd4
011 = CLCxIN[15] is selected for lcxd4
010 = CLCxIN[14] is selected for lcxd4
001 = CLCxIN[13] is selected for lcxd4
000 = CLCxIN[12] is selected for lcxd4
bit 3 Unimplemented: Read as ‘0’
bit 2-0 LCxD3S<2:0>: Input Data 3 Selection Control bits(1)
111 = CLCxIN[15] is selected for lcxd3
110 = CLCxIN[14] is selected for lcxd3
101 = CLCxIN[13] is selected for lcxd3
100 = CLCxIN[12] is selected for lcxd3
011 = CLCxIN[11] is selected for lcxd3
010 = CLCxIN[10] is selected for lcxd3
001 = CLCxIN[9] is selected for lcxd3
000 = CLCxIN[8] is selected for lcxd3
Note 1: See Table 24-1 for signal names associated with inputs.
2011 Microchip Technology Inc. Preliminary DS41609A-page 281
PIC16(L)F1508/9
REGISTER 24-5: CLCxGLS0: GATE 1 LOGIC SELECT REGISTER
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
LCxG1D4T LCxG1D4N LCxG1D3T LCxG1D3N LCxG1D2T LCxG1D2N LCxG1D1T LCxG1D1N
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 LCxG1D4T: Gate 1 Data 4 True (non-inverted) bit
1 = lcxd4T is gated into lcxg1
0 = lcxd4T is not gated into lcxg1
bit 6 LCxG1D4N: Gate 1 Data 4 Negated (inverted) bit
1 = lcxd4N is gated into lcxg1
0 = lcxd4N is not gated into lcxg1
bit 5 LCxG1D3T: Gate 1 Data 3 True (non-inverted) bit
1 = lcxd3T is gated into lcxg1
0 = lcxd3T is not gated into lcxg1
bit 4 LCxG1D3N: Gate 1 Data 3 Negated (inverted) bit
1 = lcxd3N is gated into lcxg1
0 = lcxd3N is not gated into lcxg1
bit 3 LCxG1D2T: Gate 1 Data 2 True (non-inverted) bit
1 = lcxd2T is gated into lcxg1
0 = lcxd2T is not gated into lcxg1
bit 2 LCxG1D2N: Gate 1 Data 2 Negated (inverted) bit
1 = lcxd2N is gated into lcxg1
0 = lcxd2N is not gated into lcxg1
bit 1 LCxG1D1T: Gate 1 Data 1 True (non-inverted) bit
1 = lcxd1T is gated into lcxg1
0 = lcxd1T is not gated into lcxg1
bit 0 LCxG1D1N: Gate 1 Data 1 Negated (inverted) bit
1 = lcxd1N is gated into lcxg1
0 = lcxd1N is not gated into lcxg1
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REGISTER 24-6: CLCxGLS1: GATE 2 LOGIC SELECT REGISTER
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
LCxG2D4T LCxG2D4N LCxG2D3T LCxG2D3N LCxG2D2T LCxG2D2N LCxG2D1T LCxG2D1N
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 LCxG2D4T: Gate 2 Data 4 True (non-inverted) bit
1 = lcxd4T is gated into lcxg2
0 = lcxd4T is not gated into lcxg2
bit 6 LCxG2D4N: Gate 2 Data 4 Negated (inverted) bit
1 = lcxd4N is gated into lcxg2
0 = lcxd4N is not gated into lcxg2
bit 5 LCxG2D3T: Gate 2 Data 3 True (non-inverted) bit
1 = lcxd3T is gated into lcxg2
0 = lcxd3T is not gated into lcxg2
bit 4 LCxG2D3N: Gate 2 Data 3 Negated (inverted) bit
1 = lcxd3N is gated into lcxg2
0 = lcxd3N is not gated into lcxg2
bit 3 LCxG2D2T: Gate 2 Data 2 True (non-inverted) bit
1 = lcxd2T is gated into lcxg2
0 = lcxd2T is not gated into lcxg2
bit 2 LCxG2D2N: Gate 2 Data 2 Negated (inverted) bit
1 = lcxd2N is gated into lcxg2
0 = lcxd2N is not gated into lcxg2
bit 1 LCxG2D1T: Gate 2 Data 1 True (non-inverted) bit
1 = lcxd1T is gated into lcxg2
0 = lcxd1T is not gated into lcxg2
bit 0 LCxG2D1N: Gate 2 Data 1 Negated (inverted) bit
1 = lcxd1N is gated into lcxg2
0 = lcxd1N is not gated into lcxg2
2011 Microchip Technology Inc. Preliminary DS41609A-page 283
PIC16(L)F1508/9
REGISTER 24-7: CLCxGLS2: GATE 3 LOGIC SELECT REGISTER
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
LCxG3D4T LCxG3D4N LCxG3D3T LCxG3D3N LCxG3D2T LCxG3D2N LCxG3D1T LCxG3D1N
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 LCxG3D4T: Gate 3 Data 4 True (non-inverted) bit
1 = lcxd4T is gated into lcxg3
0 = lcxd4T is not gated into lcxg3
bit 6 LCxG3D4N: Gate 3 Data 4 Negated (inverted) bit
1 = lcxd4N is gated into lcxg3
0 = lcxd4N is not gated into lcxg3
bit 5 LCxG3D3T: Gate 3 Data 3 True (non-inverted) bit
1 = lcxd3T is gated into lcxg3
0 = lcxd3T is not gated into lcxg3
bit 4 LCxG3D3N: Gate 3 Data 3 Negated (inverted) bit
1 = lcxd3N is gated into lcxg3
0 = lcxd3N is not gated into lcxg3
bit 3 LCxG3D2T: Gate 3 Data 2 True (non-inverted) bit
1 = lcxd2T is gated into lcxg3
0 = lcxd2T is not gated into lcxg3
bit 2 LCxG3D2N: Gate 3 Data 2 Negated (inverted) bit
1 = lcxd2N is gated into lcxg3
0 = lcxd2N is not gated into lcxg3
bit 1 LCxG3D1T: Gate 3 Data 1 True (non-inverted) bit
1 = lcxd1T is gated into lcxg3
0 = lcxd1T is not gated into lcxg3
bit 0 LCxG3D1N: Gate 3 Data 1 Negated (inverted) bit
1 = lcxd1N is gated into lcxg3
0 = lcxd1N is not gated into lcxg3
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DS41609A-page 284 Preliminary 2011 Microchip Technology Inc.
REGISTER 24-8: CLCxGLS3: GATE 4 LOGIC SELECT REGISTER
R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
LCxG4D4T LCxG4D4N LCxG4D3T LCxG4D3N LCxG4D2T LCxG4D2N LCxG4D1T LCxG4D1N
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 LCxG4D4T: Gate 4 Data 4 True (non-inverted) bit
1 = lcxd4T is gated into lcxg4
0 = lcxd4T is not gated into lcxg4
bit 6 LCxG4D4N: Gate 4 Data 4 Negated (inverted) bit
1 = lcxd4N is gated into lcxg4
0 = lcxd4N is not gated into lcxg4
bit 5 LCxG4D3T: Gate 4 Data 3 True (non-inverted) bit
1 = lcxd3T is gated into lcxg4
0 = lcxd3T is not gated into lcxg4
bit 4 LCxG4D3N: Gate 4 Data 3 Negated (inverted) bit
1 = lcxd3N is gated into lcxg4
0 = lcxd3N is not gated into lcxg4
bit 3 LCxG4D2T: Gate 4 Data 2 True (non-inverted) bit
1 = lcxd2T is gated into lcxg4
0 = lcxd2T is not gated into lcxg4
bit 2 LCxG4D2N: Gate 4 Data 2 Negated (inverted) bit
1 = lcxd2N is gated into lcxg4
0 = lcxd2N is not gated into lcxg4
bit 1 LCxG4D1T: Gate 4 Data 1 True (non-inverted) bit
1 = lcxd1T is gated into lcxg4
0 = lcxd1T is not gated into lcxg4
bit 0 LCxG4D1N: Gate 4 Data 1 Negated (inverted) bit
1 = lcxd1N is gated into lcxg4
0 = lcxd1N is not gated into lcxg4
2011 Microchip Technology Inc. Preliminary DS41609A-page 285
PIC16(L)F1508/9
REGISTER 24-9: CLCDATA: CLC DATA OUTPUT
U-0 U-0 U-0 U-0 R-0 R-0 R-0 R-0
— — — — MLC4OUT MLC3OUT MLC2OUT MLC1OUT
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 Unimplemented: Read as ‘0’
bit 3 MLC4OUT: Mirror copy of LC4OUT bit
bit 2 MLC3OUT: Mirror copy of LC3OUT bit
bit 1 MLC2OUT: Mirror copy of LC2OUT bit
bit 0 MLC1OUT: Mirror copy of LC1OUT bit
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DS41609A-page 286 Preliminary 2011 Microchip Technology Inc.
TABLE 24-3: SUMMARY OF REGISTERS ASSOCIATED WITH CLCx
Name Bit7 Bit6 Bit5 Bit4 BIt3 Bit2 Bit1 Bit0 Register
on Page
ANSELC ANSC7 ANSC6 —— ANSC3 ANSC2 ANSC1 ANSC0 123
APFCON — — —SSSEL T1GSEL — CLC1SEL NCO1SEL 112
CLC1CON LC1EN LC1OE LC1OUT LC1INTP LC1INTN LC1MODE<2:0> 277
CLC2CON LC2EN LC2OE LC2OUT LC2INTP LC2INTN LC2MODE<2:0> 277
CLCDATA — — — — MLC4OUT MLC3OUT MLC2OUT MLC1OUT 281
CLC1GLS0 LC1G1D4T LC1G1D4N LC1G1D3T LC1G1D3N LC1G1D2T LC1G1D2N LC1G1D1T LC1G1D1N 281
CLC1GLS1 LC1G2D4T LC1G2D4N LC1G2D3T LC1G2D3N LC1G2D2T LC1G2D2N LC1G2D1T LC1G2D1N 282
CLC1GLS2 LC1G3D4T LC1G3D4N LC1G3D3T LC1G3D3N LC1G3D2T LC1G3D2N LC1G3D1T LC1G3D1N 283
CLC1GLS3 LC1G4D4T LC1G4D4N LC1G4D3T LC1G4D3N LC1G4D2T LC1G4D2N LC1G4D1T LC1G4D1N 284
CLC1POL LC1POL — — — LC1G4POL LC1G3POL LC1G2POL LC1G1POL 278
CLC1SEL0 — LC1D2S<2:0> — LC1D1S<2:0> 279
CLC1SEL1 — LC1D4S<2:0> — LC1D3S<2:0> 280
CLC2GLS0 LC2G1D4T LC2G1D4N LC2G1D3T LC2G1D3N LC2G1D2T LC2G1D2N LC2G1D1T LC2G1D1N 281
CLC2GLS1 LC2G2D4T LC2G2D4N LC2G2D3T LC2G2D3N LC2G2D2T LC2G2D2N LC2G2D1T LC2G2D1N 282
CLC2GLS2 LC2G3D4T LC2G3D4N LC2G3D3T LC2G3D3N LC2G3D2T LC2G3D2N LC2G3D1T LC2G3D1N 283
CLC2GLS3 LC2G4D4T LC2G4D4N LC2G4D3T LC2G4D3N LC2G4D2T LC2G4D2N LC2G4D1T LC2G4D1N 284
CLC2POL LC2POL — — — LC2G4POL LC2G3POL LC2G2POL LC2G1POL 278
CLC2SEL0 — LC2D2S<2:0> — LC2D1S<2:0> 279
CLC2SEL1 — LC2D4S<2:0> — LC2D3S<2:0> 280
CLC3GLS0 LC3G1D4T LC3G1D4N LC3G1D3T LC3G1D3N LC3G1D2T LC3G1D2N LC3G1D1T LC3G1D1N 281
CLC3GLS1 LC3G2D4T LC3G2D4N LC3G2D3T LC3G2D3N LC3G2D2T LC3G2D2N LC3G2D1T LC3G2D1N 282
CLC3GLS2 LC3G3D4T LC3G3D4N LC3G3D3T LC3G3D3N LC3G3D2T LC3G3D2N LC3G3D1T LC3G3D1N 283
CLC3GLS3 LC3G4D4T LC3G4D4N LC3G4D3T LC3G4D3N LC3G4D2T LC3G4D2N LC3G4D1T LC3G4D1N 284
CLC3POL LC3POL — — — LC3G4POL LC3G3POL LC3G2POL LC3G1POL 278
CLC3SEL0 — LC3D2S<2:0> — LC3D1S<2:0> 279
CLC3SEL1 — LC3D4S<2:0> — LC3D3S<2:0> 280
CLC4GLS0 LC4G1D4T LC4G1D4N LC4G1D3T LC4G1D3N LC4G1D2T LC4G1D2N LC4G1D1T LC4G1D1N 281
CLC4GLS1 LC4G2D4T LC4G2D4N LC4G2D3T LC4G2D3N LC4G2D2T LC4G2D2N LC4G2D1T LC4G2D1N 282
CLC4GLS2 LC4G3D4T LC4G3D4N LC4G3D3T LC4G3D3N LC4G3D2T LC4G3D2N LC4G3D1T LC4G3D1N 283
CLC4GLS3 LC4G4D4T LC4G4D4N LC4G4D3T LC4G4D3N LC4G4D2T LC4G4D2N LC4G4D1T LC4G4D1N 284
CLC4POL LC4POL — — — LC4G4POL LC4G3POL LC4G2POL LC4G1POL 278
CLC4SEL0 — LC4D2S<2:0> — LC4D1S<2:0> 279
CLC4SEL1 — LC4D4S<2:0> — LC4D3S<2:0> 280
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
PIE3 ———— CLC4IE CLC3IE CLC2IE CLC1IE 81
PIR3 ———— CLC4IF CLC3IF CLC2IF CLC1IF 84
TRISA — — TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
Legend: — = unimplemented read as ‘0’,. Shaded cells are not used for CLC module.
Note 1: Unimplemented, read as ‘1’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 287
PIC16(L)F1508/9
25.0 NUMERICALLY CONTROLLED
OSCILLATOR (NCO) MODULE
The Numerically Controlled Oscillator (NCOx) module
is a timer that uses the overflow from the addition of an
increment value to divide the input frequency. The
advantage of the addition method over simple counter
driven timer is that the resolution of division does not
vary with the divider value. The NCOx is most useful for
applications that require frequency accuracy and fine
resolution at a fixed duty cycle.
Features of the NCOx include:
• 16-bit increment function
• Fixed Duty Cycle (FDC) mode
• Pulse Frequency (PF) mode
• Output pulse width control
• Multiple clock input sources
• Output polarity control
• Interrupt capability
Figure 25-1 is a simplified block diagram of the NCOx
module.
PIC16(L)F1508/9
DS41609A-page 288 Preliminary 2011 Microchip Technology Inc.
FIGURE 25-1: NUMERICALLY CONTROLLED OSCILLATOR (NCOx) MODULE SIMPLIFIED BLOCK DIAGRAM
N
xEN
LC1OUT
HFINTOSC
NCO1CLK
2
N
xCKS<2:0>
Note 1: The increment registers are double-buffered to allow for value changes to be made without first disabling the NCOx
module. They are shown here for reference. The buffers are not user-accessible.
(1)
FOSC
10
00
01
11
Increment
Buffer
Accumulator
Overflow
NCOx Clock
DQ
Q
SQ
Q
Overflow
R
NCO
xOUT
16
20
20
Interrupt event Set NCOxIF flag
NxPOL
NCOx Clock
0
1
NxPFM
To CLC, CWG
Ripple Counter Reset
N
x
PWS<2:0>
3
16
NCOx
NxOE
TRIS Control
2011 Microchip Technology Inc. Preliminary DS41609A-page 289
PIC16(L)F1508/9
25.1 NCOx OPERATION
The NCOx operates by repeatedly adding a fixed value
to an accumulator. Additions occur at the input clock
rate. The accumulator will overflow with a carry
periodically, which is the raw NCOx output. This
effectively reduces the input clock by the ratio of the
addition value to the maximum accumulator value. See
Equation 25-1.
The NCOx output can be further modified by stretching
the pulse or toggling a flip-flop. The modified NCOx
output is then distributed internally to other peripherals
and optionally output to a pin. The accumulator overflow
also generates an interrupt.
The NCOx period changes in discrete steps to create an
average frequency. This output depends on the ability of
the receiving circuit (i.e., CWG or external resonant
converter circuitry) to average the NCOx output to
reduce uncertainty.
25.1.1 NCOx CLOCK SOURCES
Clock sources available to the NCOx include:
•HFINTOSC
•F
OSC
•LC1OUT
• CLKIN pin
The NCOx clock source is selected by configuring the
NxCKS<2:0> bits in the NCOxCLK register.
25.1.2 ACCUMULATOR
The accumulator is a 20-bit register. Read and write
access to the accumulator is available through three
registers:
• NCOxACCL
• NCOxACCH
• NCOxACCU
25.1.3 ADDER
The NCOx Adder is a full adder, which operates
independently from the system clock. The addition of
the previous result and the increment value replaces
the accumulator value on the rising edge of each input
clock.
25.1.4 INCREMENT REGISTERS
The Increment value is stored in two 8-bit registers
making up a 16-bit increment. In order of LSB to MSB
they are:
• NCOxINCL
• NCOxINCH
Both of the registers are readable and writeable. The
Increment registers are double-buffered to allow for
value changes to be made without first disabling the
NCOx module.
The buffer loads are immediate when the module is dis-
abled. Writing to the NCOxINCH register first is neces-
sary because then the buffer is loaded synchronously
with the NCOx operation after the write is executed on
the NCOxINCL register.
EQUATION 25-1:
Note: The increment buffer registers are not
user-accessible.
FOVERFLOW NCO Clock Frequency Increment Value
2n
----------------------------------------------------------------------------------------------------------------=
n = Accumulator width in bits
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DS41609A-page 290 Preliminary 2011 Microchip Technology Inc.
25.2 FIXED DUTY CYCLE (FDC) MODE
In Fixed Duty Cycle (FDC) mode, every time the
accumulator overflows, the output is toggled. This
provides a 50% duty cycle, provided that the increment
value remains constant. For more information, see
Figure 25-2.
The FDC mode is selected by clearing the NxPFM bit
in the NCOxCON register.
25.3 PULSE FREQUENCY (PF) MODE
In Pulse Frequency (PF) mode, every time the accumu-
lator overflows, the output becomes active for one or
more clock periods. Once the clock period expires, the
output returns to an inactive state. This provides a
pulsed output.
The output becomes active on the rising clock edge
immediately following the overflow event. For more
information, see Figure 25-2.
The value of the active and inactive states depends on
the polarity bit, NxPOL in the NCOxCON register.
The PF mode is selected by setting the NxPFM bit in
the NCOxCON register.
25.3.1 OUTPUT PULSE WIDTH CONTROL
When operating in PF mode, the active state of the out-
put can vary in width by multiple clock periods. Various
pulse widths are selected with the NxPWS<2:0> bits in
the NCOxCLK register.
When the selected pulse width is greater than the
accumulator overflow time frame, the output of the
NCOx operation is indeterminate.
25.4 OUTPUT POLARITY CONTROL
The last stage in the NCOx module is the output polar-
ity. The NxPOL bit in the NCOxCON register selects the
output polarity. Changing the polarity while the inter-
rupts are enabled will cause an interrupt for the result-
ing output transition.
The NCOx output can be used internally by source
code or other peripherals. Accomplish this by reading
the NxOUT (read-only) bit of the NCOxCON register.
PIC16(L)F1508/9
DS41609A-page 291 Preliminary 2011 Microchip Technology Inc.
FIGURE 25-2: FDC OUTPUT MODE OPERATION DIAGRAM
2000h
02000h 04000h 06000h 08000h 0A000h 0C000h 0E000h 10000h 02000h 04000h 06000h 08000h 0A000h 0C000h 0E000h 10000h 02000h 04000h
0000h 2000h 4000h 6000h 8000h A000h C000h E000h 0000h 2000h 4000h 6000h 8000h A000h C000h E000h 0000h 2000h
TadderTadder
Tadder_
Overflow is the
Clock Source
NCOx
NCOx
Accumulator Input Overflow
NCOx
Overflow
Interrupt
NCOx Output
NCOx Output PF mode
NCOx Output PF mode
MSB of the accumulator
Tadder
Increment
Value
Input
Value
Accumulator
Accumulator
Event
FDC mode
NCOX PWS = 000
NCOx PWS = 010
PWS = 000
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DS41609A-page 292 Preliminary 2011 Microchip Technology Inc.
25.5 Interrupts
When the accumulator overflows, the NCOx Interrupt
Flag bit, NCOxIF, of the PIRx register is set. To enable
the interrupt event, the following bits must be set:
• NxEN bit of the NCOxCON register
• NCOxIE bit of the PIEx register
• PEIE bit of the INTCON register
• GIE bit of the INTCON register
The interrupt must be cleared by software by clearing
the NCOxIF bit in the Interrupt Service Routine.
25.6 Effects of a Reset
All of the NCOx registers are cleared to zero as the
result of a Reset.
25.7 Operation In Sleep
The NCO module operates independently from the
system clock and will continue to run during Sleep,
provided that the clock source selected remains
active.
The HFINTOSC remains active during Sleep when the
NCO module is enabled and the HFINTOSC is
selected as the clock source, regardless of the system
clock source selected.
In other words, if the HFINTOSC is simultaneously
selected as the system clock and the NCO clock
source, when the NCO is enabled, the CPU will go idle
during Sleep, but the NCO will continue to operate and
the HFINTOSC will remain active.
This will have a direct effect on the Sleep mode current.
25.8 Alternate Pin Locations
This module incorporates I/O pins that can be moved to
other locations with the use of the alternate pin function
register, APFCON. To determine which pins can be
moved and what their default locations are upon a
Reset, see Section 11.1 “Alternate Pin Function” for
more information.
2011 Microchip Technology Inc. Preliminary DS41609A-page 293
PIC16(L)F1508/9
25.9 NCOx Control Registers
REGISTER 25-2: NCOxCLK: NCOx INPUT CLOCK CONTROL REGISTER
REGISTER 25-1: NCOxCON: NCOx CONTROL REGISTER
R/W-0/0 R/W-0/0 R-0/0 R/W-0/0 U-0 U-0 U-0 R/W-0/0
NxEN NxOE NxOUT NxPOL — — —NxPFM
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7 NxEN: NCOx Enable bit
1 = NCOx module is enabled
0 = NCOx module is disabled
bit 6 NxOE: NCOx Output Enable bit
1 = NCOx output pin is enabled
0 = NCOx output pin is disabled
bit 5 NxOUT: NCOx Output bit
1 = NCOx output is high
0 = NCOx output is low
bit 4 NxPOL: NCOx Polarity bit
1 = NCOx output signal is active-high
0 = NCOx output signal is active-low
bit 3-1 Unimplemented: Read as ‘0’.
bit 0 NxPFM: NCOx Pulse Frequency Mode bit
1 = NCOx operates in Pulse Frequency mode
0 = NCOx operates in Fixed Duty Cycle mode
R/W-0/0 R/W-0/0 R/W-0/0 U-0 U-0 U-0 R/W-0/0 R/W-0/0
NxPWS<2:0> ———NxCKS<1:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-5 NxPWS<2:0>: NCOx Output Pulse Width Select bits(1, 2)
111 = 128 NCOx clock periods
110 = 64 NCOx clock periods
101 = 32 NCOx clock periods
100 = 16 NCOx clock periods
011 = 8 NCOx clock periods
010 = 4 NCOx clock periods
001 = 2 NCOx clock periods
000 = 1 NCOx clock periods
bit 4-2 Unimplemented: Read as ‘0’
bit 1-0 NxCKS<1:0>: NCOx Clock Source Select bits
11 = NCO1CLK
10 = LC1OUT
01 = FOSC
00 = HFINTOSC (16 MHz)
Note 1: NxPWS applies only when operating in Pulse Frequency mode.
2: If NCOx pulse width is greater than NCOx overflow period, operation is undeterminate.
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DS41609A-page 294 Preliminary 2011 Microchip Technology Inc.
REGISTER 25-3: NCOxACCL: NCOx ACCUMULATOR REGISTER – LOW BYTE
REGISTER 25-4: NCOxACCH: NCOx ACCUMULATOR REGISTER – HIGH BYTE
REGISTER 25-5: NCOxACCU: NCOx ACCUMULATOR REGISTER – UPPER BYTE
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
NCOxACC<7:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 NCOxACC<7:0>: NCOx Accumulator, low byte
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
NCOxACC<15:8>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 NCOxACC<15:8>: NCOx Accumulator, high byte
U-0 U-0 U-0 U-0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
— — — — NCOxACC<19:16>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-4 Unimplemented: Read as ‘0’
bit 3-0 NCOxACC<19:16>: NCOx Accumulator, upper byte
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REGISTER 25-6: NCOxINCL: NCOx INCREMENT REGISTER – LOW BYTE
REGISTER 25-7: NCOxINCH: NCOx INCREMENT REGISTER – HIGH BYTE
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-1/1
NCOxINC<7:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 NCOxINC<7:0>: NCOx Increment, low byte
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
NCOxINC<15:8>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared
bit 7-0 NCOxINC<15:8>: NCOx Increment, high byte
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DS41609A-page 296 Preliminary 2011 Microchip Technology Inc.
TABLE 25-1: SUMMARY OF REGISTERS ASSOCIATED WITH NCOx
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
APFCON ———SSSEL T1GSEL —CLC1SEL NCO1SEL 112
INTCON GIE PEIE TMR0IE INTE IOCIE TMR0IF INTF IOCIF 78
NCO1ACCH NCO1ACC<15:8> 294
NCO1ACCL NCO1ACC<7:0> 294
NCO1ACCU — NCO1ACC<19:16> 294
NCO1CLK N1PWS<2:0> ———N1CKS<1:0>293
NCO1CON N1EN N1OE N1OUT N1POL ———N1PFM293
NCO1INCH NCO1INC<15:8> 295
NCO1INCL NCO1INC<7:0> 295
PIE2 OSFIE C2IE C1IE —BCL1IE NCO1IE — — 80
PIR2 OSFIF C2IF C1IF —BCL1IF NCO1IF — — 83
TRISA —— TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
Legend: x = unknown, u = unchanged, — = unimplemented read as ‘0’, q = value depends on condition. Shaded cells are not
used for NCOx module.
Note 1: Unimplemented, read as ‘1’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 297
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26.0 COMPLEMENTARY WAVEFORM
GENERATOR (CWG) MODULE
The Complementary Waveform Generator (CWG) pro-
duces a complementary waveform with dead-band
delay from a selection of input sources.
The CWG module has the following features:
• Selectable dead-band clock source control
• Selectable input sources
• Output enable control
• Output polarity control
• Dead-band control with independent 6-bit rising
and falling edge dead-band counters
• Auto-shutdown control with:
- Selectable shutdown sources
- Auto-restart enable
- Auto-shutdown pin override control
2011 Microchip Technology Inc. Preliminary DS41609A-page 298
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FIGURE 26-1: SIMPLIFIED CWG BLOCK DIAGRAM
cwg_clock
GxCS
Input Source
PWM1OUT
PWM2OUT
NCO1OUT
CWG1FLT (INT pin)
GxASDFLT
LC2OUT
GxASCLC
FOSC
HFINTOSC
GxIS
LC1OUT
Auto-Shutdown
Source
G
x
POLA
1
1
3
QS
RQ
EN
R
GxARSEN
CWGxDBR
G
x
POLB
6
CWGxDBF
0
1
0
1
00
10
11
‘0’
‘1’
00
10
11
‘0’
‘1’
G
x
ASDLB
2
GxASDLA
2
CWGxA
CWGxB
GxASDLA = 01
GxASDLB = 01
GxASE
GxOEA
GxOEB
=
EN
R
6
=TRISx
TRISx
x = CWG module number
PWM3OUT
PWM4OUT
QS
RQ
QD S
WRITE
GxASE Data Bit
shutdown
set dominate
async_C1OUT
async_C2OUT
async_C2OUT
GxASDC2
async_C1OUT
GxASDC1
2011 Microchip Technology Inc. Preliminary DS41609A-page 299
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FIGURE 26-2: TYPICAL CWG OPERATION WITH PWM1 (NO AUTO-SHUTDOWN)
Rising Edge D
Falling Edge Dead Band
Rising Edge Dead Band
Falling Edge Dead Band
cwg_clock
PWM1
CWGxA
CWGxB
Rising Edge
Dead Band
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DS41609A-page 300 Preliminary 2011 Microchip Technology Inc.
26.1 Fundamental Operation
The CWG generates a two output complementary
waveform from one of four selectable input sources.
The off-to-on transition of each output can be delayed
from the on-to-off transition of the other output, thereby,
creating a time delay immediately where neither output
is driven. This is referred to as dead time and is covered
in Section 26.5 “Dead-Band Control”. A typical
operating waveform, with dead band, generated from a
single input signal is shown in Figure 26-2.
It may be necessary to guard against the possibility of
circuit faults or a feedback event arriving too late or not
at all. In this case, the active drive must be terminated
before the Fault condition causes damage. This is
referred to as auto-shutdown and is covered in
Section 26.9 “Auto-shutdown Control”.
26.2 Clock Source
The CWG module allows the following clock sources
to be selected:
• Fosc (system clock)
• HFINTOSC (16 MHz only)
The clock sources are selected using the G1CS0 bit of
the CWGxCON0 register (Register 26-1).
26.3 Selectable Input Sources
The CWG can generate the complementary waveform
for the following input sources:
• async_C1OUT
• async_C2OUT
•PWM1OUT
•PWM2OUT
•PWM3OUT
•PWM4OUT
• NCO1OUT
•LC1OUT
The input sources are selected using the GxIS<2:0>
bits in the CWGxCON1 register (Register 26-2).
26.4 Output Control
Immediately after the CWG module is enabled, the
complementary drive is configured with both CWGxA
and CWGxB drives cleared.
26.4.1 OUTPUT ENABLES
Each CWG output pin has individual output enable
control. Output enables are selected with the GxOEA
and GxOEB bits of the CWGxCON0 register. When an
output enable control is cleared, the module asserts no
control over the pin. When an output enable is set, the
override value or active PWM waveform is applied to
the pin per the port priority selection. The output pin
enables are dependent on the module enable bit,
GxEN. When GxEN is cleared, CWG output enables
and CWG drive levels have no effect.
26.4.2 POLARITY CONTROL
The polarity of each CWG output can be selected
independently. When the output polarity bit is set, the
corresponding output is active high. Clearing the output
polarity bit configures the corresponding output as
active low. However, polarity does not affect the
override levels. Output polarity is selected with the
GxPOLA and GxPOLB bits of the CWGxCON0 register.
26.5 Dead-Band Control
Dead-band control provides for non-overlapping output
signals to prevent shoot-through current in power
switches. The CWG contains two 6-bit dead-band
counters. One dead-band counter is used for the rising
edge of the input source control. The other is used for
the falling edge of the input source control.
Dead band is timed by counting CWG clock periods
from zero up to the value in the rising or falling dead-
band counter registers. See CWGxDBR and
CWGxDBF registers (Register 26-4 and Register 26-5,
respectively).
26.6 Rising Edge Dead Band
The rising edge dead-band delays the turn-on of the
CWGxA output from when the CWGxB output is turned
off. The rising edge dead-band time starts when the
rising edge of the input source signal goes true. When
this happens, the CWGxB output is immediately turned
off and the rising edge dead-band delay time starts.
When the rising edge dead-band delay time is reached,
the CWGxA output is turned on.
The CWGxDBR register sets the duration of the dead-
band interval on the rising edge of the input source
signal. This duration is from 0 to 64 counts of dead band.
Dead band is always counted off the edge on the input
source signal. A count of 0 (zero), indicates that no
dead band is present.
If the input source signal is not present for enough time
for the count to be completed, no output will be seen on
the respective output.
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26.7 Falling Edge Dead Band
The falling edge dead band delays the turn-on of the
CWGxB output from when the CWGxA output is turned
off. The falling edge dead-band time starts when the
falling edge of the input source goes true. When this
happens, the CWGxA output is immediately turned off
and the falling edge dead-band delay time starts. When
the falling edge dead-band delay time is reached, the
CWGxB output is turned on.
The CWGxDBF register sets the duration of the dead-
band interval on the falling edge of the input source sig-
nal. This duration is from 0 to 64 counts of dead band.
Dead band is always counted off the edge on the input
source signal. A count of 0 (zero), indicates that no
dead band is present.
If the input source signal is not present for enough time
for the count to be completed, no output will be seen on
the respective output.
Refer to Figure 26-3 and Figure 26-4 for examples.
26.8 Dead-Band Uncertainty
When the rising and falling edges of the input source
triggers the dead-band counters, the input may be asyn-
chronous. This will create some uncertainty in the dead-
band time delay. The maximum uncertainty is equal to
one CWG clock period. Refer to Equation 26-1 for more
detail.
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FIGURE 26-3: DEAD-BAND OPERATION, CWGxDBR = 01H, CWGxDBF = 02H
FIGURE 26-4: DEAD-BAND OPERATION, CWGxDBR = 03H, CWGxDBF = 04H, SOURCE SHORTER THAN DEAD BAND
Input Source
CWGxA
CWGxB
cwg_clock
source shorter than dead band
Input Source
CWGxA
CWGxB
cwg_clock
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EQUATION 26-1: DEAD-BAND
UNCERTAINTY
TDEADBAND_UNCERTAINTY 1
Fcwg_clock
-----------------------------=
Therefore:
Fcwg_clock 16 MHz=
1
16 MHz
-------------------=
62.5ns=
TDEADBAND_UNCERTAINTY 1
Fcwg_clock
-----------------------------=
Example:
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DS41609A-page 304 Preliminary 2011 Microchip Technology Inc.
26.9 Auto-shutdown Control
Auto-shutdown is a method to immediately override the
CWG output levels with specific overrides that allow for
safe shutdown of the circuit. The shutdown state can be
either cleared automatically or held until cleared by
software.
26.9.1 SHUTDOWN
The shutdown state can be entered by either of the fol-
lowing two methods:
• Software generated
• External Input
26.9.1.1 Software Generated Shutdown
Setting the GxASE bit of the CWGxCON2 register will
force the CWG into the shutdown state.
When auto-restart is disabled, the shutdown state will
persist as long as the GxASE bit is set.
When auto-restart is enabled, the GxASE bit will clear
automatically and resume operation on the next rising
edge event. See Figure 26-6.
26.9.1.2 External Input Source
External shutdown inputs provide the fastest way to
safely suspend CWG operation in the event of a Fault
condition. When any of the selected shutdown inputs
goes active, the CWG outputs will immediately go to
the selected override levels without software delay. Any
combination of two input sources can be selected to
cause a shutdown condition. The sources are:
• async_C1OUT
• async_C2OUT
•LC2OUT
•CWG1FLT
Shutdown inputs are selected using the GxASDS0 and
GxASDS1 bits of the CWGxCON2 register.
(Register 26-3).
26.10 Operation During Sleep
The CWG module operates independently from the
system clock and will continue to run during Sleep,
provided that the clock and input sources selected
remain active.
The HFINTOSC remains active during Sleep, provided
that the CWG module is enabled, the input source is
active, and the HFINTOSC is selected as the clock
source, regardless of the system clock source
selected.
In other words, if the HFINTOSC is simultaneously
selected as the system clock and the CWG clock
source, when the CWG is enabled and the input
source is active, the CPU will go idle during Sleep, but
the CWG will continue to operate and the HFINTOSC
will remain active.
This will have a direct effect on the Sleep mode current.
Note: Shutdown inputs are level sensitive, not
edge sensitive. The shutdown state can-
not be cleared, except by disabling auto-
shutdown, as long as the shutdown input
level persists.
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26.11 Configuring the CWG
The following steps illustrate how to properly configure
the CWG to ensure a synchronous start:
1. Ensure that the TRIS control bits corresponding
to CWGxA and CWGxB are set so that both are
configured as inputs.
2. Clear the GxEN bit, if not already cleared.
3. Set desired dead-band times with the CWGxDBR
and CWGxDBF registers.
4. Setup the following controls in CWGxCON2
auto-shutdown register:
• Select desired shutdown source.
• Select both output overrides to the desired
levels (this is necessary even if not using
auto-shutdown because start-up will be from
a shutdown state).
• Set the GxASE bit and clear the GxARSEN
bit.
5. Select the desired input source using the
CWGxCON1 register.
6. Configure the following controls in CWGxCON0
register:
• Select desired clock source.
• Select the desired output polarities.
• Set the output enables for the outputs to be
used.
7. Set the GxEN bit.
8. Clear TRIS control bits corresponding to
CWGxA and CWGxB to be used to configure
those pins as outputs.
9. If auto-restart is to be used, set the GxARSEN
bit and the GxASE bit will be cleared automati-
cally. Otherwise, clear the GxASE bit to start the
CWG.
26.11.1 PIN OVERRIDE LEVELS
The levels driven to the output pins, while the shutdown
input is true, are controlled by the GxASDLA and
GxASDLB bits of the CWGxCON2 register
(Register 26-3). GxASDLA controls the CWG1A
override level and GxASDLB controls the CWG1B
override level. The control bit logic level corresponds to
the output logic drive level while in the shutdown state.
The polarity control does not apply to the override level.
26.11.2 AUTO-SHUTDOWN RESTART
After an auto-shutdown event has occurred, there are
two ways to have resume operation:
• Software controlled
• Auto-restart
The restart method is selected with the GxARSEN bit
of the CWGxCON2 register. Waveforms of software
controlled and automatic restarts are shown in
Figure 26-5 and Figure 26-6.
26.11.2.1 Software controlled restart
When the GxARSEN bit of the CWGxCON2 register is
cleared, the CWG must be restarted after an auto-shut-
down event by software.
Clearing the shutdown state requires all selected shut-
down inputs to be low, otherwise the GxASE bit will
remain set. The overrides will remain in effect until the
first rising edge event after the GxASE bit is cleared.
The CWG will then resume operation.
26.11.2.2 Auto-Restart
When the GxARSEN bit of the CWGxCON2 register is
set, the CWG will restart from the auto-shutdown state
automatically.
The GxASE bit will clear automatically when all shut-
down sources go low. The overrides will remain in
effect until the first rising edge event after the GxASE
bit is cleared. The CWG will then resume operation.
2011 Microchip Technology Inc. Preliminary DS41609A-page 306
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FIGURE 26-5: SHUTDOWN FUNCTIONALITY, AUTO-RESTART DISABLED (GxARSEN = 0,GxASDLA = 01, GxASDLB = 01)
FIGURE 26-6: SHUTDOWN FUNCTIONALITY, AUTO-RESTART ENABLED (GxARSEN = 1,GxASDLA = 01, GxASDLB = 01)
Shutdown
GxASE Cleared by Software
Output Resumes
No Shutdown
CWG Input
GxASE
CWG1A
Source
Shutdown Source
Shutdown Event Ceases
Tri-State (No Pulse)
CWG1B Tri-State (No Pulse)
Shutdown
Tri-State (No Pulse)
GxASE auto-cleared by hardware
Output Resumes
No Shutdown
CWG Input
GxASE
CWG1A
Source
Shutdown Source
Shutdown Event Ceases
CWG1B
Tri-State (No Pulse)
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26.12 CWG Control Registers
REGISTER 26-1: CWGxCON0: CWG CONTROL REGISTER 0
R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0 U-0 U-0 R/W-0/0
GxEN GxOEB GxOEA GxPOLB GxPOLA ——GxCS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared q = Value depends on condition
bit 7 GxEN: CWGx Enable bit
1 = Module is enabled
0 = Module is disabled
bit 6 GxOEB: CWGxB Output Enable bit
1 = CWGxB is available on appropriate I/O pin
0 = CWGxB is not available on appropriate I/O pin
bit 5 GxOEA: CWGxA Output Enable bit
1 = CWGxA is available on appropriate I/O pin
0 = CWGxA is not available on appropriate I/O pin
bit 4 GxPOLB: CWGxB Output Polarity bit
1 = Output is inverted polarity
0 = Output is normal polarity
bit 3 GxPOLA: CWGxA Output Polarity bit
1 = Output is inverted polarity
0 = Output is normal polarity
bit 2-1 Unimplemented: Read as ‘0’
bit 0 GxCS0: CWGx Clock Source Select bit
1 =HFINTOSC
0 =F
OSC
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DS41609A-page 308 Preliminary 2011 Microchip Technology Inc.
REGISTER 26-2: CWGxCON1: CWG CONTROL REGISTER 1
R/W-x/u R/W-x/u R/W-x/u R/W-x/u U-0 R/W-0/0 R/W-0/0 R/W-0/0
GxASDLB<1:0> GxASDLA<1:0> —GxIS<2:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared q = Value depends on condition
bit 7-6 GxASDLB<1:0>: CWGx Shutdown State for CWGxB
When an auto shutdown event is present (GxASE = 1):
11 = CWGxB pin is driven to ‘1’, regardless of the setting of the GxPOLB bit.
10 = CWGxB pin is driven to ‘0’, regardless of the setting of the GxPOLB bit.
01 = CWGxB pin is tri-stated
00 = CWGxB pin is driven to it’s inactive state after the selected dead-band interval. GxPOLB still will
control the polarity of the output.
bit 5-4 GxASDLA<1:0>: CWGx Shutdown State for CWGxA
When an auto shutdown event is present (GxASE = 1):
11 = CWGxA pin is driven to ‘1’, regardless of the setting of the GxPOLA bit.
10 = CWGxA pin is driven to ‘0’, regardless of the setting of the GxPOLA bit.
01 = CWGxA pin is tri-stated
00 = CWGxA pin is driven to it’s inactive state after the selected dead-band interval. GxPOLA still will
control the polarity of the output.
bit 3 Unimplemented: Read as ‘0’
bit 2-0 GxIS<2:0>: CWGx Input Source Select bits
111 =LC1OUT
110 = NCO1OUT
101 =PWM4OUT
100 =PWM3OUT
011 =PWM2OUT
010 =PWM1OUT
001 = async_C1OUT
000 = async_C2OUT
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REGISTER 26-3: CWGxCON2: CWG CONTROL REGISTER 2
R/W-0/0 R/W-0/0 U-0 U-0 R/W-0/0 R/W-0/0 R/W-0/0 R/W-0/0
GxASE GxARSEN — — GxASDC2 GxASDC1 GxASDFLT GxASDCLC2
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared q = Value depends on condition
bit 7 GxASE: Auto-Shutdown Event Status bit
1 = An auto-shutdown event has occurred
0 = No auto-shutdown event has occurred
bit 6 GxARSEN: Auto-Restart Enable bit
1 = Auto-restart is enabled
0 = Auto-restart is disabled
bit 5-4 Unimplemented: Read as ‘0’
bit 3 GxASDC2: CWG Auto-shutdown on Comparator 2 Enable
1 = Shutdown when Comparator 2 output is high
0 = Comparator 2 output has no effect on shutdown
bit 2 GxASDC1: CWG Auto-shutdown on Comparator 1 Enable
1 = Shutdown when Comparator 1 output is high
0 = Comparator 1 output has no effect on shutdown
bit 1 GxASDFLT: CWG Auto-shutdown on FLT Enable bit
1 = Shutdown when CWG1FLT input is low
0 =CWG1FLT
input has no effect on shutdown
bit 0 GxASDCLC2: CWG Auto-shutdown on CLC2 Enable bit
1 = Shutdown when LC2OUT is high
0 = LC2OUT has no effect on shutdown
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DS41609A-page 310 Preliminary 2011 Microchip Technology Inc.
REGISTER 26-4: CWGxDBR: COMPLEMENTARY WAVEFORM GENERATOR (CWGx) RISING
DEAD-BAND COUNT REGISTER
REGISTER 26-5: CWGxDBF: COMPLEMENTARY WAVEFORM GENERATOR (CWGx) FALLING
DEAD-BAND COUNT REGISTER
U-0 U-0 R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
— — CWGxDBR<5:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared q = Value depends on condition
bit 7-6 Unimplemented: Read as ‘0’
bit 5-0 CWGxDBR<5:0>: Complementary Waveform Generator (CWGx) Rising counts
11 1111 = 63-64 counts of dead band
11 1110 = 62-63 counts of dead band


00 0010 = 2-3 counts of dead band
00 0001 = 1-2 counts of dead band
00 0000 = 0 counts of dead band
U-0 U-0 R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u R/W-x/u
— — CWGxDBF<5:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
u = Bit is unchanged x = Bit is unknown -n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set ‘0’ = Bit is cleared q = Value depends on condition
bit 7-6 Unimplemented: Read as ‘0’
bit 5-0 CWGxDBF<5:0>: Complementary Waveform Generator (CWGx) Falling counts
11 1111 = 63-64 counts of dead band
11 1110 = 62-63 counts of dead band


00 0010 = 2-3 counts of dead band
00 0001 = 1-2 counts of dead band
00 0000 = 0 counts of dead band. Dead-band generation is bypassed.
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TABLE 26-1: SUMMARY OF REGISTERS ASSOCIATED WITH CWG
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Register
on Page
ANSELA — — — ANSA4 — ANSA2 ANSA1 ANSA0 115
CWG1CON0 G1EN G1OEB G1OEA G1POLB G1POLA ——G1CS0307
CWG1CON1 G1ASDLB<1:0> G1ASDLA<1:0> — — G1IS<1:0> 308
CWG1CON2 G1ASE G1ARSEN — — G1ASDC2 G1ASDC1 G1ASDSFLT G1ASDSCLC2 309
CWG1DBF — — CWG1DBF<5:0> 310
CWG1DBR — — CWG1DBR<5:0> 310
TRISA — — TRISA5 TRISA4 —(1) TRISA2 TRISA1 TRISA0 114
TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 122
Legend: x = unknown, u = unchanged, – = unimplemented locations read as ‘0’. Shaded cells are not used by CWG.
Note 1: Unimplemented, read as ‘1’.
PIC16(L)F1508/9
DS41609A-page 312 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 313
PIC16(L)F1508/9
27.0 IN-CIRCUIT SERIAL
PROGRAMMING™ (ICSP™)
ICSP™ programming allows customers to manufacture
circuit boards with unprogrammed devices. Programming
can be done after the assembly process allowing the
device to be programmed with the most recent firmware
or a custom firmware. Five pins are needed for ICSP™
programming:
• ICSPCLK
• ICSPDAT
•MCLR
/VPP
•VDD
•VSS
In Program/Verify mode the Program Memory, User IDs
and the Configuration Words are programmed through
serial communications. The ICSPDAT pin is a bidirec-
tional I/O used for transferring the serial data and the
ICSPCLK pin is the clock input. For more information on
ICSP™ refer to the “PIC12(L)F1501/PIC16(L)F150X
Memory Programming Specification” (DS41573).
27.1 High-Voltage Programming Entry
Mode
The device is placed into High-Voltage Programming
Entry mode by holding the ICSPCLK and ICSPDAT
pins low then raising the voltage on MCLR/VPP to VIHH.
27.2 Low-Voltage Programming Entry
Mode
The Low-Voltage Programming Entry mode allows the
PIC Flash MCUs devices to be programmed using VDD
only, without high voltage. When the LVP bit of
Configuration Words is set to ‘1’, the low-voltage ICSP
programming entry is enabled. To disable the
Low-Voltage ICSP mode, the LVP bit must be
programmed to ‘0’.
Entry into the Low-Voltage Programming Entry mode
requires the following steps:
1. MCLR is brought to VIL.
2. A 32-bit key sequence is presented on
ICSPDAT, while clocking ICSPCLK.
Once the key sequence is complete, MCLR must be
held at VIL for as long as Program/Verify mode is to be
maintained.
If low-voltage programming is enabled (LVP = 1), the
MCLR Reset function is automatically enabled and
cannot be disabled. See Section 6.4 “MCLR” for more
information.
The LVP bit can only be reprogrammed to ‘0’ by using
the High-Voltage Programming mode.
27.3 Common Programming Interfaces
Connection to a target device is typically done through
an ICSP™ header. A commonly found connector on
development tools is the RJ-11 in the 6P6C (6 pin, 6
connector) configuration. See Figure 27-1.
FIGURE 27-1: ICD RJ-11 STYLE
CONNECTOR INTERFACE
Another connector often found in use with the PICkit™
programmers is a standard 6-pin header with 0.1 inch
spacing. Refer to Figure 27-2.
1
2
3
4
5
6
Target
Bottom Side
PC Board
VPP/MCLR VSS
ICSPCLK
VDD
ICSPDAT
NC
Pin Description*
1 = VPP/MCLR
2 = VDD Target
3 = VSS (ground)
4 = ICSPDAT
5 = ICSPCLK
6 = No Connect
PIC16(L)F1508/9
DS41609A-page 314 Preliminary 2011 Microchip Technology Inc.
FIGURE 27-2: PICkit™ PROGRAMMER STYLE CONNECTOR INTERFACE
For additional interface recommendations, refer to your
specific device programmer manual prior to PCB
design.
It is recommended that isolation devices be used to
separate the programming pins from other circuitry.
The type of isolation is highly dependent on the specific
application and may include devices such as resistors,
diodes, or even jumpers. See Figure 27-3 for more
information.
FIGURE 27-3: TYPICAL CONNECTION FOR ICSP™ PROGRAMMING
1
2
3
4
5
6
* The 6-pin header (0.100" spacing) accepts 0.025" square pins.
Pin Description*
1 = VPP/MCLR
2 = VDD Target
3 = VSS (ground)
4 = ICSPDAT
5 = ICSPCLK
6 = No Connect
Pin 1 Indicator
VDD
VPP
VSS
External
Device to be
Data
Clock
VDD
MCLR/VPP
VSS
ICSPDAT
ICSPCLK
**
*
To Normal Connections
*Isolation devices (as required).
Programming
Signals Programmed
VDD
2011 Microchip Technology Inc. Preliminary DS41609A-page 315
PIC16(L)F1508/9
28.0 INSTRUCTION SET SUMMARY
Each PIC16 instruction is a 14-bit word containing the
operation code (opcode) and all required operands.
The op codes are broken into three broad categories.
• Byte Oriented
• Bit Oriented
• Literal and Control
The literal and control category contains the most var-
ied instruction word format.
Table 28-3 lists the instructions recognized by the
MPASMTM assembler.
All instructions are executed within a single instruction
cycle, with the following exceptions, which may take
two or three cycles:
• Subroutine takes two cycles (CALL, CALLW)
• Returns from interrupts or subroutines take two
cycles (RETURN, RETLW, RETFIE)
• Program branching takes two cycles (GOTO, BRA,
BRW, BTFSS, BTFSC, DECFSZ, INCSFZ)
• One additional instruction cycle will be used when
any instruction references an indirect file register
and the file select register is pointing to program
memory.
One instruction cycle consists of 4 oscillator cycles; for
an oscillator frequency of 4 MHz, this gives a nominal
instruction execution rate of 1 MHz.
All instruction examples use the format ‘0xhh’ to
represent a hexadecimal number, where ‘h’ signifies a
hexadecimal digit.
28.1 Read-Modify-Write Operations
Any instruction that specifies a file register as part of
the instruction performs a Read-Modify-Write (R-M-W)
operation. The register is read, the data is modified,
and the result is stored according to either the instruc-
tion, or the destination designator ‘d’. A read operation
is performed on a register even if the instruction writes
to that register.
TABLE 28-1: OPCODE FIELD
DESCRIPTIONS
TABLE 28-2: ABBREVIATION
DESCRIPTIONS
Field Description
fRegister file address (0x00 to 0x7F)
WWorking register (accumulator)
bBit address within an 8-bit file register
kLiteral field, constant data or label
xDon’t care location (= 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.
dDestination select; d = 0: store result in W,
d = 1: store result in file register f.
Default is d = 1.
nFSR or INDF number. (0-1)
mm Pre-post increment-decrement mode
selection
Field Description
PC Program Counter
TO Time-out bit
CCarry bit
DC Digit carry bit
ZZero bit
PD Power-down bit
PIC16(L)F1508/9
DS41609A-page 316 Preliminary 2011 Microchip Technology Inc.
FIGURE 28-1: GENERAL FORMAT FOR
INSTRUCTIONS
Byte-oriented file register operations
13 8 7 6 0
d = 0 for destination W
OPCODE d f (FILE #)
d = 1 for destination f
f = 7-bit file register address
Bit-oriented file register operations
13 10 9 7 6 0
OPCODE b (BIT #) f (FILE #)
b = 3-bit bit address
f = 7-bit file register address
Literal and control operations
13 8 7 0
OPCODE k (literal)
k = 8-bit immediate value
13 11 10 0
OPCODE k (literal)
k = 11-bit immediate value
General
CALL and GOTO instructions only
MOVLP instruction only
13 5 4 0
OPCODE k (literal)
k = 5-bit immediate value
MOVLB instruction only
13 9 8 0
OPCODE k (literal)
k = 9-bit immediate value
BRA instruction only
FSR Offset instructions
13 7 6 5 0
OPCODE n k (literal)
n = appropriate FSR
FSR Increment instructions
13 7 6 0
OPCODE k (literal)
k = 7-bit immediate value
13 3 2 1 0
OPCODE n m (mode)
n = appropriate FSR
m = 2-bit mode value
k = 6-bit immediate value
13 0
OPCODE
OPCODE only
2011 Microchip Technology Inc. Preliminary DS41609A-page 317
PIC16(L)F1508/9
TABLE 28-3: PIC16(L)F1508/9 ENHANCED INSTRUCTION SET
Mnemonic,
Operands Description Cycles
14-Bit Opcode Status
Affected Notes
MSb LSb
BYTE-ORIENTED FILE REGISTER OPERATIONS
ADDWF
ADDWFC
ANDWF
ASRF
LSLF
LSRF
CLRF
CLRW
COMF
DECF
INCF
IORWF
MOVF
MOVWF
RLF
RRF
SUBWF
SUBWFB
SWAPF
XORWF
f, d
f, d
f, d
f, d
f, d
f, d
f
–
f, d
f, d
f, d
f, d
f, d
f
f, d
f, d
f, d
f, d
f, d
f, d
Add W and f
Add with Carry W and f
AND W with f
Arithmetic Right Shift
Logical Left Shift
Logical Right Shift
Clear f
Clear W
Complement f
Decrement f
Increment f
Inclusive OR W with f
Move f
Move W to f
Rotate Left f through Carry
Rotate Right f through Carry
Subtract W from f
Subtract with Borrow W from f
Swap nibbles in f
Exclusive OR W with f
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
00
11
00
11
11
11
00
00
00
00
00
00
00
00
00
00
00
11
00
00
0111
1101
0101
0111
0101
0110
0001
0001
1001
0011
1010
0100
1000
0000
1101
1100
0010
1011
1110
0110
dfff
dfff
dfff
dfff
dfff
dfff
lfff
0000
dfff
dfff
dfff
dfff
dfff
1fff
dfff
dfff
dfff
dfff
dfff
dfff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
00xx
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
C, DC, Z
C, DC, Z
Z
C, Z
C, Z
C, Z
Z
Z
Z
Z
Z
Z
Z
C
C
C, DC, Z
C, DC, Z
Z
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
BYTE ORIENTED SKIP OPERATIONS
DECFSZ
INCFSZ
f, d
f, d
Decrement f, Skip if 0
Increment f, Skip if 0
1(2)
1(2)
00
00
1011
1111
dfff
dfff
ffff
ffff
1, 2
1, 2
BIT-ORIENTED FILE REGISTER OPERATIONS
BCF
BSF
f, b
f, b
Bit Clear f
Bit Set f
1
1
01
01
00bb
01bb
bfff
bfff
ffff
ffff
2
2
BIT-ORIENTED SKIP OPERATIONS
BTFSC
BTFSS
f, b
f, b
Bit Test f, Skip if Clear
Bit Test f, Skip if Set
1 (2)
1 (2)
01
01
10bb
11bb
bfff
bfff
ffff
ffff
1, 2
1, 2
LITERAL OPERATIONS
ADDLW
ANDLW
IORLW
MOVLB
MOVLP
MOVLW
SUBLW
XORLW
k
k
k
k
k
k
k
k
Add literal and W
AND literal with W
Inclusive OR literal with W
Move literal to BSR
Move literal to PCLATH
Move literal to W
Subtract W from literal
Exclusive OR literal with W
1
1
1
1
1
1
1
1
11
11
11
00
11
11
11
11
1110
1001
1000
0000
0001
0000
1100
1010
kkkk
kkkk
kkkk
001k
1kkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
C, DC, Z
Z
Z
C, DC, Z
Z
Note 1: 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.
2: If this instruction addresses an INDF register and the MSb of the corresponding FSR is set, this instruction will require one
additional instruction cycle.
PIC16(L)F1508/9
DS41609A-page 318 Preliminary 2011 Microchip Technology Inc.
TABLE 28-3: PIC16(L)F1508/9 ENHANCED INSTRUCTION SET (CONTINUED)
Mnemonic,
Operands Description Cycles
14-Bit Opcode Status
Affected Notes
MSb LSb
CONTROL OPERATIONS
BRA
BRW
CALL
CALLW
GOTO
RETFIE
RETLW
RETURN
k
–
k
–
k
k
k
–
Relative Branch
Relative Branch with W
Call Subroutine
Call Subroutine with W
Go to address
Return from interrupt
Return with literal in W
Return from Subroutine
2
2
2
2
2
2
2
2
11
00
10
00
10
00
11
00
001k
0000
0kkk
0000
1kkk
0000
0100
0000
kkkk
0000
kkkk
0000
kkkk
0000
kkkk
0000
kkkk
1011
kkkk
1010
kkkk
1001
kkkk
1000
INHERENT OPERATIONS
CLRWDT
NOP
OPTION
RESET
SLEEP
TRIS
–
–
–
–
–
f
Clear Watchdog Timer
No Operation
Load OPTION_REG register with W
Software device Reset
Go into Standby mode
Load TRIS register with W
1
1
1
1
1
1
00
00
00
00
00
00
0000
0000
0000
0000
0000
0000
0110
0000
0110
0000
0110
0110
0100
0000
0010
0001
0011
0fff
TO, PD
TO, PD
C-COMPILER OPTIMIZED
ADDFSR
MOVIW
MOVWI
n, k
n mm
k[n]
n mm
k[n]
Add Literal k to FSRn
Move Indirect FSRn to W with pre/post inc/dec
modifier, mm
Move INDFn to W, Indexed Indirect.
Move W to Indirect FSRn with pre/post inc/dec
modifier, mm
Move W to INDFn, Indexed Indirect.
1
1
1
1
1
11
00
11
00
11
0001
0000
1111
0000
1111
0nkk
0001
0nkk
0001
1nkk
kkkk
0nmm
kkkk
1nmm
kkkk
Z
Z
2, 3
2
2, 3
2
Note 1: 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.
2: If this instruction addresses an INDF register and the MSb of the corresponding FSR is set, this instruction will require
one additional instruction cycle.
3: See Table in the MOVIW and MOVWI instruction descriptions.
2011 Microchip Technology Inc. Preliminary DS41609A-page 319
PIC16(L)F1508/9
28.2 Instruction Descriptions
ADDFSR Add Literal to FSRn
Syntax: [ label ] ADDFSR FSRn, k
Operands: -32 k 31
n [ 0, 1]
Operation: FSR(n) + k FSR(n)
Status Affected: None
Description: The signed 6-bit literal ‘k’ is added to
the contents of the FSRnH:FSRnL
register pair.
FSRn is limited to the range 0000h -
FFFFh. Moving beyond these bounds
will cause the FSR to wrap around.
ADDLW Add literal and W
Syntax: [ label ] ADDLW k
Operands: 0 k 255
Operation: (W) + k (W)
Status Affected: C, DC, Z
Description: The contents of the W register are
added to the eight-bit literal ‘k’ and the
result is placed in the W register.
ADDWF Add W and f
Syntax: [ label ] ADDWF f,d
Operands: 0 f 127
d 0,1
Operation: (W) + (f) (destination)
Status Affected: C, DC, Z
Description: Add the contents of the W register
with register ‘f’. If ‘d’ is ‘0’, the result is
stored in the W register. If ‘d’ is ‘1’, the
result is stored back in register ‘f’.
ADDWFC ADD W and CARRY bit to f
Syntax: [ label ] ADDWFC f {,d}
Operands: 0 f 127
d [0,1]
Operation: (W) + (f) + (C) dest
Status Affected: C, DC, Z
Description: Add W, the Carry flag and data mem-
ory 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’.
ANDLW AND literal with W
Syntax: [ label ] ANDLW k
Operands: 0 k 255
Operation: (W) .AND. (k) (W)
Status Affected: Z
Description: The contents of W register are
AND’ed with the eight-bit literal ‘k’.
The result is placed in the W register.
ANDWF AND W with f
Syntax: [ label ] ANDWF f,d
Operands: 0 f 127
d 0,1
Operation: (W) .AND. (f) (destination)
Status Affected: Z
Description: AND the W register with register ‘f’. If
‘d’ is ‘0’, the result is stored in the W
register. If ‘d’ is ‘1’, the result is stored
back in register ‘f’.
ASRF Arithmetic Right Shift
Syntax: [ label ] ASRF f {,d}
Operands: 0 f 127
d [0,1]
Operation: (f<7>) dest<7>
(f<7:1>) dest<6:0>,
(f<0>) C,
Status Affected: C, Z
Description: The contents of register ‘f’ are shifted
one bit to the right through the Carry
flag. The MSb remains unchanged. If
‘d’ is ‘0’, the result is placed in W. If ‘d’
is ‘1’, the result is stored back in reg-
ister ‘f’.
register f C
PIC16(L)F1508/9
DS41609A-page 320 Preliminary 2011 Microchip Technology Inc.
BCF Bit Clear f
Syntax: [ label ] BCF f,b
Operands: 0 f 127
0 b 7
Operation: 0 (f<b>)
Status Affected: None
Description: Bit ‘b’ in register ‘f’ is cleared.
BRA Relative Branch
Syntax: [ label ] BRA label
[ label ] BRA $+k
Operands: -256 label - PC + 1 255
-256 k 255
Operation: (PC) + 1 + k PC
Status Affected: None
Description: Add the signed 9-bit literal ‘k’ to the
PC. Since the PC will have incre-
mented to fetch the next instruction,
the new address will be PC + 1 + k.
This instruction is a two-cycle instruc-
tion. This branch has a limited range.
BRW Relative Branch with W
Syntax: [ label ] BRW
Operands: None
Operation: (PC) + (W) PC
Status Affected: None
Description: Add the contents of W (unsigned) to
the PC. Since the PC will have incre-
mented to fetch the next instruction,
the new address will be PC + 1 + (W).
This instruction is a two-cycle instruc-
tion.
BSF Bit Set f
Syntax: [ label ] BSF f,b
Operands: 0 f 127
0 b 7
Operation: 1 (f<b>)
Status Affected: None
Description: Bit ‘b’ in register ‘f’ is set.
BTFSC Bit Test f, Skip if Clear
Syntax: [ label ] BTFSC f,b
Operands: 0 f 127
0 b 7
Operation: skip if (f<b>) = 0
Status Affected: None
Description: If bit ‘b’ in register ‘f’ is ‘1’, the next
instruction is executed.
If bit ‘b’, in register ‘f’, is ‘0’, the next
instruction is discarded, and a NOP is
executed instead, making this a
2-cycle instruction.
BTFSS Bit Test f, Skip if Set
Syntax: [ label ] BTFSS f,b
Operands: 0 f 127
0 b < 7
Operation: skip if (f<b>) = 1
Status Affected: None
Description: If bit ‘b’ in register ‘f’ is ‘0’, the next
instruction is executed.
If bit ‘b’ is ‘1’, then the next
instruction is discarded and a NOP is
executed instead, making this a
2-cycle instruction.
2011 Microchip Technology Inc. Preliminary DS41609A-page 321
PIC16(L)F1508/9
CALL Call Subroutine
Syntax: [ label ] CALL k
Operands: 0 k 2047
Operation: (PC)+ 1 TOS,
k PC<10:0>,
(PCLATH<4:3>) PC<12:11>
Status Affected: None
Description: Call Subroutine. First, return address
(PC + 1) is pushed onto the stack.
The eleven-bit immediate address is
loaded into PC bits <10:0>. The upper
bits of the PC are loaded from
PCLATH. CALL is a two-cycle instruc-
tion.
CALLW Subroutine Call With W
Syntax: [ label ] CALLW
Operands: None
Operation: (PC) +1 TOS,
(W) PC<7:0>,
(PCLATH<6:0>) PC<14:8>
Status Affected: None
Description: Subroutine call with W. First, the
return address (PC + 1) is pushed
onto the return stack. Then, the con-
tents of W is loaded into PC<7:0>,
and the contents of PCLATH into
PC<14:8>. CALLW is a two-cycle
instruction.
CLRF Clear f
Syntax: [ label ] CLRF f
Operands: 0 f 127
Operation: 00h (f)
1 Z
Status Affected: Z
Description: The contents of register ‘f’ are cleared
and the Z bit is set.
CLRW Clear W
Syntax: [ label ] CLRW
Operands: None
Operation: 00h (W)
1 Z
Status Affected: Z
Description: W register is cleared. Zero bit (Z) is
set.
CLRWDT Clear Watchdog Timer
Syntax: [ label ] CLRWDT
Operands: None
Operation: 00h WDT
0 WDT prescaler,
1 TO
1 PD
Status Affected: TO, PD
Description: CLRWDT instruction resets the Watch-
dog Timer. It also resets the prescaler
of the WDT.
Status bits TO and PD are set.
COMF Complement f
Syntax: [ label ] COMF f,d
Operands: 0 f 127
d [0,1]
Operation: (f) (destination)
Status Affected: Z
Description: The contents of register ‘f’ are com-
plemented. If ‘d’ is ‘0’, the result is
stored in W. If ‘d’ is ‘1’, the result is
stored back in register ‘f’.
DECF Decrement f
Syntax: [ label ] DECF f,d
Operands: 0 f 127
d [0,1]
Operation: (f) - 1 (destination)
Status Affected: Z
Description: Decrement register ‘f’. If ‘d’ is ‘0’, the
result is stored in the W
register. If ‘d’ is ‘1’, the result is stored
back in register ‘f’.
PIC16(L)F1508/9
DS41609A-page 322 Preliminary 2011 Microchip Technology Inc.
DECFSZ Decrement f, Skip if 0
Syntax: [ label ] DECFSZ f,d
Operands: 0 f 127
d [0,1]
Operation: (f) - 1 (destination);
skip if result = 0
Status Affected: None
Description: The contents of register ‘f’ are decre-
mented. If ‘d’ is ‘0’, the result is placed
in the W register. If ‘d’ is ‘1’, the result
is placed back in register ‘f’.
If the result is ‘1’, the next instruction is
executed. If the result is ‘0’, then a
NOP is executed instead, making it a
2-cycle instruction.
GOTO Unconditional Branch
Syntax: [ label ] GOTO k
Operands: 0 k 2047
Operation: k PC<10:0>
PCLATH<4:3> PC<12:11>
Status Affected: None
Description: GOTO is an unconditional branch. The
eleven-bit immediate value is loaded
into PC bits <10:0>. The upper bits of
PC are loaded from PCLATH<4:3>.
GOTO is a two-cycle instruction.
INCF Increment f
Syntax: [ label ] INCF f,d
Operands: 0 f 127
d [0,1]
Operation: (f) + 1 (destination)
Status Affected: Z
Description: The contents of register ‘f’ are incre-
mented. If ‘d’ is ‘0’, the result is placed
in the W register. If ‘d’ is ‘1’, the result
is placed back in register ‘f’.
INCFSZ Increment f, Skip if 0
Syntax: [ label ] INCFSZ f,d
Operands: 0 f 127
d [0,1]
Operation: (f) + 1 (destination),
skip if result = 0
Status Affected: None
Description: The contents of register ‘f’ are incre-
mented. If ‘d’ is ‘0’, the result is placed
in the W register. If ‘d’ is ‘1’, the result
is placed back in register ‘f’.
If the result is ‘1’, the next instruction is
executed. If the result is ‘0’, a NOP is
executed instead, making it a 2-cycle
instruction.
IORLW Inclusive OR literal with W
Syntax: [ label ] IORLW k
Operands: 0 k 255
Operation: (W) .OR. k (W)
Status Affected: Z
Description: The contents of the W register are
OR’ed with the eight-bit literal ‘k’. The
result is placed in the W register.
IORWF Inclusive OR W with f
Syntax: [ label ] IORWF f,d
Operands: 0 f 127
d [0,1]
Operation: (W) .OR. (f) (destination)
Status Affected: Z
Description: Inclusive OR the W register with regis-
ter ‘f’. If ‘d’ is ‘0’, the result is placed in
the W register. If ‘d’ is ‘1’, the result is
placed back in register ‘f’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 323
PIC16(L)F1508/9
LSLF Logical Left Shift
Syntax: [ label ] LSLF f {,d}
Operands: 0 f 127
d [0,1]
Operation: (f<7>) C
(f<6:0>) dest<7:1>
0 dest<0>
Status Affected: C, Z
Description: The contents of register ‘f’ are shifted
one bit to the left through the Carry flag.
A ‘0’ is shifted into the LSb. If ‘d’ is ‘0’,
the result is placed in W. If ‘d’ is ‘1’, the
result is stored back in register ‘f’.
LSRF Logical Right Shift
Syntax: [ label ] LSRF f {,d}
Operands: 0 f 127
d [0,1]
Operation: 0 dest<7>
(f<7:1>) dest<6:0>,
(f<0>) C,
Status Affected: C, Z
Description: The contents of register ‘f’ are shifted
one bit to the right through the Carry
flag. A ‘0’ is shifted into the MSb. If ‘d’ is
‘0’, the result is placed in W. If ‘d’ is ‘1’,
the result is stored back in register ‘f’.
register f 0
C
register f C0
MOVF Move f
Syntax: [ label ] MOVF f,d
Operands: 0 f 127
d [0,1]
Operation: (f) (dest)
Status Affected: Z
Description: The contents of register f is moved to
a destination dependent upon the
status of d. If d = 0,
destination is W register. If d = 1, the
destination is file register f itself. d = 1
is useful to test a file register since
status flag Z is affected.
Words: 1
Cycles: 1
Example: MOVF FSR, 0
After Instruction
W = value in FSR register
Z=
1
PIC16(L)F1508/9
DS41609A-page 324 Preliminary 2011 Microchip Technology Inc.
MOVIW Move INDFn to W
Syntax: [ label ] MOVIW ++FSRn
[ label ] MOVIW --FSRn
[ label ] MOVIW FSRn++
[ label ] MOVIW FSRn--
[ label ] MOVIW k[FSRn]
Operands: n [0,1]
mm [00,01, 10, 11]
-32 k 31
Operation: INDFn W
Effective address is determined by
• FSR + 1 (preincrement)
• FSR - 1 (predecrement)
• FSR + k (relative offset)
After the Move, the FSR value will be
either:
• FSR + 1 (all increments)
• FSR - 1 (all decrements)
• Unchanged
Status Affected: Z
Mode Syntax mm
Preincrement ++FSRn 00
Predecrement --FSRn 01
Postincrement FSRn++ 10
Postdecrement FSRn-- 11
Description: This instruction is used to move data
between W and one of the indirect
registers (INDFn). Before/after this
move, the pointer (FSRn) is updated by
pre/post incrementing/decrementing it.
Note: The INDFn registers are not
physical registers. Any instruction that
accesses an INDFn register actually
accesses the register at the address
specified by the FSRn.
FSRn is limited to the range 0000h -
FFFFh. Incrementing/decrementing it
beyond these bounds will cause it to
wrap-around.
MOVLB Move literal to BSR
Syntax: [ label ] MOVLB k
Operands: 0 k 15
Operation: k BSR
Status Affected: None
Description: The five-bit literal ‘k’ is loaded into the
Bank Select Register (BSR).
MOVLP Move literal to PCLATH
Syntax: [ label ] MOVLP k
Operands: 0 k 127
Operation: k PCLATH
Status Affected: None
Description: The seven-bit literal ‘k’ is loaded into the
PCLATH register.
MOVLW Move literal to W
Syntax: [ label ] MOVLW k
Operands: 0 k 255
Operation: k (W)
Status Affected: None
Description: The eight-bit literal ‘k’ is loaded into W
register. The “don’t cares” will assem-
ble as ‘0’s.
Words: 1
Cycles: 1
Example: MOVLW 0x5A
After Instruction
W = 0x5A
MOVWF Move W to f
Syntax: [ label ] MOVWF f
Operands: 0 f 127
Operation: (W) (f)
Status Affected: None
Description: Move data from W register to register
‘f’.
Words: 1
Cycles: 1
Example: MOVWF OPTION_REG
Before Instruction
OPTION_REG = 0xFF
W = 0x4F
After Instruction
OPTION_REG = 0x4F
W = 0x4F
2011 Microchip Technology Inc. Preliminary DS41609A-page 325
PIC16(L)F1508/9
MOVWI Move W to INDFn
Syntax: [ label ] MOVWI ++FSRn
[ label ] MOVWI --FSRn
[ label ] MOVWI FSRn++
[ label ] MOVWI FSRn--
[ label ] MOVWI k[FSRn]
Operands: n [0,1]
mm [00,01, 10, 11]
-32 k 31
Operation: W INDFn
Effective address is determined by
• FSR + 1 (preincrement)
• FSR - 1 (predecrement)
• FSR + k (relative offset)
After the Move, the FSR value will be
either:
• FSR + 1 (all increments)
• FSR - 1 (all decrements)
Unchanged
Status Affected: None
Mode Syntax mm
Preincrement ++FSRn 00
Predecrement --FSRn 01
Postincrement FSRn++ 10
Postdecrement FSRn-- 11
Description: This instruction is used to move data
between W and one of the indirect
registers (INDFn). Before/after this
move, the pointer (FSRn) is updated by
pre/post incrementing/decrementing it.
Note: The INDFn registers are not
physical registers. Any instruction that
accesses an INDFn register actually
accesses the register at the address
specified by the FSRn.
FSRn is limited to the range 0000h -
FFFFh. Incrementing/decrementing it
beyond these bounds will cause it to
wrap-around.
The increment/decrement operation on
FSRn WILL NOT affect any Status bits.
NOP No Operation
Syntax: [ label ] NOP
Operands: None
Operation: No operation
Status Affected: None
Description: No operation.
Words: 1
Cycles: 1
Example: NOP
OPTION Load OPTION_REG Register
with W
Syntax: [ label ] OPTION
Operands: None
Operation: (W) OPTION_REG
Status Affected: None
Description: Move data from W register to
OPTION_REG register.
RESET Software Reset
Syntax: [ label ] RESET
Operands: None
Operation: Execute a device Reset. Resets the
nRI flag of the PCON register.
Status Affected: None
Description: This instruction provides a way to
execute a hardware Reset by soft-
ware.
PIC16(L)F1508/9
DS41609A-page 326 Preliminary 2011 Microchip Technology Inc.
RETFIE Return from Interrupt
Syntax: [ label ] RETFIE
Operands: None
Operation: TOS PC,
1 GIE
Status Affected: None
Description: Return from Interrupt. Stack is POPed
and Top-of-Stack (TOS) is loaded in
the PC. Interrupts are enabled by
setting Global Interrupt Enable bit,
GIE (INTCON<7>). This is a two-cycle
instruction.
Words: 1
Cycles: 2
Example: RETFIE
After Interrupt
PC = TOS
GIE = 1
RETLW Return with literal in W
Syntax: [ label ] RETLW k
Operands: 0 k 255
Operation: k (W);
TOS PC
Status Affected: None
Description: The W register is loaded with the eight
bit literal ‘k’. The program counter is
loaded from the top of the stack (the
return address). This is a two-cycle
instruction.
Words: 1
Cycles: 2
Example:
TABLE
CALL TABLE;W contains table
;offset value
• ;W now has table value
•
•
ADDWF PC ;W = offset
RETLW k1 ;Begin table
RETLW k2 ;
•
•
•
RETLW kn ; End of table
Before Instruction
W = 0x07
After Instruction
W = value of k8
RETURN Return from Subroutine
Syntax: [ label ] RETURN
Operands: None
Operation: TOS PC
Status Affected: None
Description: Return from subroutine. The stack is
POPed and the top of the stack (TOS)
is loaded into the program counter.
This is a two-cycle instruction.
RLF Rotate Left f through Carry
Syntax: [ label ] RLF f,d
Operands: 0 f 127
d [0,1]
Operation: See description below
Status Affected: C
Description: The contents of register ‘f’ are rotated
one bit to the left through the Carry
flag. If ‘d’ is ‘0’, the result is placed in
the W register. If ‘d’ is ‘1’, the result is
stored back in register ‘f’.
Words: 1
Cycles: 1
Example: RLF REG1,0
Before Instruction
REG1 = 1110 0110
C=0
After Instruction
REG1 = 1110 0110
W = 1100 1100
C=1
Register fC
2011 Microchip Technology Inc. Preliminary DS41609A-page 327
PIC16(L)F1508/9
RRF Rotate Right f through Carry
Syntax: [ label ] RRF f,d
Operands: 0 f 127
d [0,1]
Operation: See description below
Status Affected: C
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
the W register. If ‘d’ is ‘1’, the result is
placed back in register ‘f’.
SLEEP Enter Sleep mode
Syntax: [ label ]SLEEP
Operands: None
Operation: 00h WDT,
0 WDT prescaler,
1 TO,
0 PD
Status Affected: TO, PD
Description: The power-down Status bit, PD is
cleared. Time-out Status bit, TO is
set. Watchdog Timer and its pres-
caler are cleared.
The processor is put into Sleep mode
with the oscillator stopped.
Register fC
SUBLW Subtract W from literal
Syntax: [ label ]SUBLW k
Operands: 0 k 255
Operation: k - (W) W)
Status Affected: C, DC, Z
Description: The W register is subtracted (2’s com-
plement method) from the eight-bit
literal ‘k’. The result is placed in the W
register.
SUBWF Subtract W from f
Syntax: [ label ] SUBWF f,d
Operands: 0 f 127
d [0,1]
Operation: (f) - (W) destination)
Status Affected: C, DC, Z
Description: Subtract (2’s complement method) W
register from register ‘f’. If ‘d’ is ‘0’, the
result is stored in the W
register. If ‘d’ is ‘1’, the result is stored
back in register ‘f.
SUBWFB Subtract W from f with Borrow
Syntax: SUBWFB f {,d}
Operands: 0 f 127
d [0,1]
Operation: (f) – (W) – (B) dest
Status Affected: C, DC, Z
Description: Subtract W and the BORROW flag
(CARRY) from register ‘f’ (2’s comple-
ment method). If ‘d’ is ‘0’, the result is
stored in W. If ‘d’ is ‘1’, the result is
stored back in register ‘f’.
C = 0W k
C = 1W k
DC = 0W<3:0> k<3:0>
DC = 1W<3:0> k<3:0>
C = 0W f
C = 1W f
DC = 0W<3:0> f<3:0>
DC = 1W<3:0> f<3:0>
PIC16(L)F1508/9
DS41609A-page 328 Preliminary 2011 Microchip Technology Inc.
SWAPF Swap Nibbles in f
Syntax: [ label ] SWAPF f,d
Operands: 0 f 127
d [0,1]
Operation: (f<3:0>) (destination<7:4>),
(f<7:4>) (destination<3:0>)
Status Affected: None
Description: The upper and lower nibbles of regis-
ter ‘f’ are exchanged. If ‘d’ is ‘0’, the
result is placed in the W register. If ‘d’
is ‘1’, the result is placed in register ‘f’.
TRIS Load TRIS Register with W
Syntax: [ label ] TRIS f
Operands: 5 f 7
Operation: (W) TRIS register ‘f’
Status Affected: None
Description: Move data from W register to TRIS
register.
When ‘f’ = 5, TRISA is loaded.
When ‘f’ = 6, TRISB is loaded.
When ‘f’ = 7, TRISC is loaded.
XORLW Exclusive OR literal with W
Syntax: [ label ]XORLW k
Operands: 0 k 255
Operation: (W) .XOR. k W)
Status Affected: Z
Description: The contents of the W register are
XOR’ed with the eight-bit
literal ‘k’. The result is placed in the
W register.
XORWF Exclusive OR W with f
Syntax: [ label ] XORWF f,d
Operands: 0 f 127
d [0,1]
Operation: (W) .XOR. (f) destination)
Status Affected: Z
Description: Exclusive OR the contents of the W
register with register ‘f’. If ‘d’ is ‘0’, the
result is stored in the W register. If ‘d’
is ‘1’, the result is stored back in regis-
ter ‘f’.
2011 Microchip Technology Inc. Preliminary DS41609A-page 329
PIC16(L)F1508/9
29.0 ELECTRICAL SPECIFICATIONS
Absolute Maximum Ratings(†)
Ambient temperature under bias....................................................................................................... -40°C to +125°C
Storage temperature ........................................................................................................................ -65°C to +150°C
Voltage on VDD with respect to VSS, PIC16F1508/9 .......................................................................... -0.3V to +6.5V
Voltage on VDD with respect to VSS, PIC16LF1508/9 ........................................................................ -0.3V to +4.0V
Voltage on MCLR with respect to Vss ................................................................................................. -0.3V to +9.0V
Voltage on all other pins with respect to VSS ........................................................................... -0.3V to (VDD + 0.3V)
Total power dissipation(1) ............................................................................................................................... 800 mW
Maximum current out of VSS pin, -40°C TA +85°C for industrial............................................................... 396 mA
Maximum current out of VSS pin, -40°C TA +125°C for extended ............................................................ 114 mA
Maximum current into VDD pin, -40°C TA +85°C for industrial.................................................................. 292 mA
Maximum current into VDD pin, -40°C TA +125°C for extended ............................................................... 107 mA
Clamp current, IK (VPIN < 0 or VPIN > VDD)20 mA
Maximum output current sunk by any I/O pin.................................................................................................... 25 mA
Maximum output current sourced by any I/O pin .............................................................................................. 25 mA
Note 1: Power dissipation is calculated as follows: PDIS = VDD x {IDD – IOH} + {(VDD – VOH) x IOH} + (VOl x
IOL).
† 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 above maximum rating conditions for
extended periods may affect device reliability.
PIC16(L)F1508/9
DS41609A-page 330 Preliminary 2011 Microchip Technology Inc.
FIGURE 29-1: PIC16F1508/9 VOLTAGE FREQUENCY GRAPH, -40°C TA +125°C
FIGURE 29-2: PIC16LF1508/9 VOLTAGE FREQUENCY GRAPH, -40°C TA +125°C
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
2: Refer to Table 29-1 for each Oscillator mode’s supported frequencies.
2.3
0
2.5
Frequency (MHz)
VDD (V)
42010 16
5.5
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
2: Refer to Table 29-1 for each Oscillator mode’s supported frequencies.
1.8
0
2.5
Frequency (MHz)
VDD (V)
420
10 16
3.6
2011 Microchip Technology Inc. Preliminary DS41609A-page 331
PIC16(L)F1508/9
29.1 DC Characteristics: PIC16(L)F1508/9-I/E (Industrial, Extended)
PIC16LF1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
PIC16F1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
Param.
No.
Sym. Characteristic Min. Typ† Max. Units Conditions
D001 VDD Supply Voltage
PIC16LF1508/9 1.8
2.5
—
—
3.6
3.6
V
V
FOSC 16 MHz
FOSC 20 MHz
D001 PIC16F1508/9 2.3
2.5
—
—
5.5
5.5
V
V
FOSC 16 MHz
FOSC 20 MHz
D002* VDR RAM Data Retention Voltage(1)
PIC16LF1508/9 1.5 — — V Device in Sleep mode
D002* PIC16F1508/9 1.7 — — V Device in Sleep mode
D002A VPOR*Power-on Reset Release Voltage
PIC16LF1508/9 — 1.6 — V
D002A PIC16F1508/9 —1.7 — V
D002B VPORR*Power-on Reset Rearm Voltage
PIC16LF1508/9 — 0.8 — V
D002B PIC16F1508/9 —1.65 — V
D003 VADFVR Fixed Voltage Reference Voltage for
ADC, Initial Accuracy
—
—
—
—
—
—
1
1
1
1
1
1
—
—
—
—
—
—
% 1.024V, VDD 2.5V, 85°C (NOTE 2)
1.024V, VDD 2.5V, 125°C (NOTE 2)
2.048V, VDD 2.5V, 85°C
2.048V, VDD 2.5V, 125°C
4.096V, VDD 4.75V, 85°C
4.096V, VDD 4.75V, 125°C
D003C* TCVFVR Temperature Coefficient, Fixed
Voltage Reference
— -130 — ppm/°C
D003D* VFVR/
VIN
Line Regulation, Fixed Voltage
Reference
— 0.270 — %/V
D004* SVDD VDD Rise Rate to ensure internal
Power-on Reset signal
0.05 — — V/ms See Section 6.1 “Power-on Reset
(POR)” for details.
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
Note 1: This is the limit to which VDD can be lowered in Sleep mode without losing RAM data.
2: For proper operation, the minimum value of the ADC positive voltage reference must be 1.8V or greater. When selecting
the FVR or the VREF+ pin as the source of the ADC positive voltage reference, be aware that the voltage must be 1.8V or
greater.
PIC16(L)F1508/9
DS41609A-page 332 Preliminary 2011 Microchip Technology Inc.
FIGURE 29-3: POR AND POR REARM WITH SLOW RISING VDD
VDD
VPOR
VPORR
VSS
VSS
NPOR
TPOR(3)
POR REARM
Note 1: When NPOR is low, the device is held in Reset.
2: TPOR 1 s typical.
3: TVLOW 2.7 s typical.
TVLOW(2)
2011 Microchip Technology Inc. Preliminary DS41609A-page 333
PIC16(L)F1508/9
29.2 DC Characteristics: PIC16(L)F1508/9-I/E (Industrial, Extended)
PIC16LF1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
PIC16F1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
Param
No.
Device
Characteristics Min. Typ† Max. Units
Conditions
VDD Note
Supply Current (IDD)(1, 2)
D010 — 2 10 A1.8FOSC = 32 kHz LP Oscillator mode
—4 12
A3.0
D010 —16 50 A2.3 FOSC = 32 kHz LP Oscillator mode
—16 55 A3.0
—19 60 A5.0
D011 — 40 110 A1.8FOSC = 1 MHz XT Oscillator mode
— 80 170 A3.0
D011 —110 200 A2.3 FOSC = 1 MHz XT Oscillator mode
—130 250 A3.0
—160 340 A5.0
D012 — 120 290 A1.8FOSC = 4 MHz XT Oscillator mode
— 220 480 A3.0
D012 —230 300 A2.3 FOSC = 4 MHz XT Oscillator mode
—300 500 A3.0
—350 700 A5.0
D013 — 30 140 A1.8FOSC = 1 MHz
EC Oscillator mode, Medium-power mode
— 50 230 A3.0
D013 —70 180 A2.3 FOSC = 1 MHz
EC Oscillator mode
Medium-power mode
—85 240 A3.0
—115 320 A5.0
D014 — 100 250 A2.3FOSC = 4 MHz
EC Oscillator mode,
Medium-power mode
— 180 430 A3.0
D014 —160 275 A2.3 FOSC = 4 MHz
EC Oscillator mode
Medium-power mode
—210 450 A3.0
—240 500 A5.0
D015 — 2.3 58 A1.8FOSC = 31 kHz
LFINTOSC mode
— 4.0 300 A3.0
D015 —14 100 A2.3 FOSC = 31 kHz
LFINTOSC mode
—15 280 A3.0
—17 400 A5.0
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
Note 1: The test conditions for all IDD measurements in active operation mode are: CLKIN = external square wave, from
rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT disabled.
2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading
and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current
consumption.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended
by the formula IR = VDD/2REXT (mA) with REXT in k.
PIC16(L)F1508/9
DS41609A-page 334 Preliminary 2011 Microchip Technology Inc.
D016 — 220 400 A1.8FOSC = 500 kHz HFINTOSC mode
— 280 600 A3.0
D016 —280 400 A2.3 FOSC = 500 kHz HFINTOSC mode
—310 550 A3.0
—360 750 A5.0
D017* — 380 700 A1.8FOSC = 8 MHz
HFINTOSC mode
— 560 1100 A3.0
D017* —490 850 A2.3 FOSC = 8 MHz
HFINTOSC mode
—600 1150 A3.0
—690 1350 A5.0
D018 — 520 1200 A1.8FOSC = 16 MHz
HFINTOSC mode
— 810 1750 A3.0
D018 —680 1200 A2.3 FOSC = 16 MHz
HFINTOSC mode
—850 1800 A3.0
—960 2000 A5.0
D019A — 750 2100 A3.0FOSC = 20 MHz
ECH mode
D019A —790 2100 A3.0 FOSC = 20 MHz
ECH mode
—810 2400 A5.0
D019B — 6 15 A1.8FOSC = 32 kHz ECL mode
—8 20
A3.0
D019B —14 43 A2.3 FOSC = 32 kHz ECL mode
—16 55 A3.0
—18 57 A5.0
D019C — 15 40 A1.8FOSC = 500 kHz ECL mode
—20 60 A3.0
D019C —32 60 A2.3 FOSC = 500 kHz ECL mode
—41 90 A3.0
—47 100 A5.0
D020 — 150 350 A1.8FOSC = 4 MHz EXTRC mode (Note 3)
— 280 680 A3.0
D020 —230 350 A2.3 FOSC = 4 MHz EXTRC mode (Note 3)
—310 680 A3.0
—370 830 A5.0
29.2 DC Characteristics: PIC16(L)F1508/9-I/E (Industrial, Extended) (Continued)
PIC16LF1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
PIC16F1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
Param
No.
Device
Characteristics Min. Typ† Max. Units
Conditions
VDD Note
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
Note 1: The test conditions for all IDD measurements in active operation mode are: CLKIN = external square wave, from
rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT disabled.
2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading
and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current
consumption.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended
by the formula IR = VDD/2REXT (mA) with REXT in k.
2011 Microchip Technology Inc. Preliminary DS41609A-page 335
PIC16(L)F1508/9
D021 — 1000 2100 A3.0FOSC = 20 MHz HS Oscillator mode
D021 —1350 2100 A3.0 FOSC = 20 MHz HS Oscillator mode
—1700 2400 A5.0
29.2 DC Characteristics: PIC16(L)F1508/9-I/E (Industrial, Extended) (Continued)
PIC16LF1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
PIC16F1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
Param
No.
Device
Characteristics Min. Typ† Max. Units
Conditions
VDD Note
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
Note 1: The test conditions for all IDD measurements in active operation mode are: CLKIN = external square wave, from
rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT disabled.
2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading
and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current
consumption.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended
by the formula IR = VDD/2REXT (mA) with REXT in k.
PIC16(L)F1508/9
DS41609A-page 336 Preliminary 2011 Microchip Technology Inc.
29.3 DC Characteristics: PIC16(L)F1508/9-I/E (Power-Down)
PIC16LF1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
PIC16F1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
Param
No. Device Characteristics Min. Typ† Max.
+85°C
Max.
+125°C Units
Conditions
VDD Note
Power-down Current (IPD)(2)
D022 — 0.025 1.0 7.0 A 1.8 Base Current: WDT, BOR, FVR,
and SOSC disabled, all Peripher-
als inactive
— 0.035 2.0 9.0 A3.0
D022 —0.20 2.0 10 A2.3 WDT, BOR, FVR, and SOSC dis-
abled, all Peripherals inactive
(VREGPM = 1; Low-Power mode)
—0.25 4.0 12 A3.0
—0.30 12 15 A5.0
D022A —10 17 18 A2.3 Base Current: WDT, BOR, FVR
and SOSC disabled, all peripheral
inactive (VREGPM = 0; Normal
Power mode)
—11 22 24 A3.0
—12 25 30 A5.0
D023 — 0.29 1.5 7 A 1.8 LPWDT Current (Note 1)
— 0.39 2.0 9 A3.0
D023 —10.5 38 44 A2.3 LPWDT Current (Note 1)
—11.3 43 48 A3.0
—12.5 46 50 A5.0
D023A — 14 44 50 A 1.8 FVR current (Note 1)
—23 48 54 A3.0
D023A —23 62 65 A2.3 FVR current (Note 1)
—30 72 75 A3.0
—34 115 120 A5.0
D024 — 7 14 16 A 3.0 BOR Current (Note 1)
D024 —15 47 50 A3.0 BOR Current (Note 1)
—17 55 66 A5.0
D24A — 0.1 4 14 A 3.0 LPBOR Current (Note 1)
D24A —11 47 50 A3.0 LPBOR Current (Note 1)
—12 52 60 A5.0
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
Note 1: The peripheral current is the sum of the base IDD or IPD and the additional current consumed when this peripheral is
enabled. The peripheral current can be determined by subtracting the base IDD or IPD current from this limit. Max
values should be used when calculating total current consumption.
2: 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.
3: A/D oscillator source is FRC.
2011 Microchip Technology Inc. Preliminary DS41609A-page 337
PIC16(L)F1508/9
D025 — 0.6 3.5 8 A 1.8 SOSC Current (Note 1)
—1.84.0 10 A3.0
D025 —11 39 45 A2.3 SOSC Current (Note 1)
—13 43 49 A3.0
—19 46 65 A5.0
D026 — .025 — — A 1.8 A/D Current (Note 1, Note 3), no
conversion in progress
— .035 — — A3.0
D026 —10 — — A2.3 A/D Current (Note 1, Note 3), no
conversion in progress
—11 — — A3.0
—12 — — A5.0
D026A* — 250 — — A 1.8 A/D Current (Note 1, Note 3),
conversion in progress
—250 — — A3.0
D026A* —280 — — A2.3 A/D Current (Note 1, Note 3),
conversion in progress
—280 — — A3.0
—280 — — A5.0
D027 — 7 25 55 A 1.8 Comparator, Low-Power mode
(Note 1)
— 8 40 65 A3.0
D027 —17 50 65 A2.3 Comparator, Low-Power mode
(Note 1)
—18 55 70 A3.0
—19 60 75 A5.0
29.3 DC Characteristics: PIC16(L)F1508/9-I/E (Power-Down) (Continued)
PIC16LF1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
PIC16F1508/9
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
Param
No. Device Characteristics Min. Typ† Max.
+85°C
Max.
+125°C Units
Conditions
VDD Note
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
Note 1: The peripheral current is the sum of the base IDD or IPD and the additional current consumed when this peripheral is
enabled. The peripheral current can be determined by subtracting the base IDD or IPD current from this limit. Max
values should be used when calculating total current consumption.
2: 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.
3: A/D oscillator source is FRC.
PIC16(L)F1508/9
DS41609A-page 338 Preliminary 2011 Microchip Technology Inc.
29.4 DC Characteristics: PIC16(L)F1508/9-I/E
DC CHARACTERISTICS
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
-40°C TA +125°C for extended
Param
No. Sym. Characteristic Min. Typ† Max. Units Conditions
VIL Input Low Voltage
I/O PORT:
D030 with TTL buffer — — 0.8 V 4.5V VDD 5.5V
D030A — — 0.15 VDD V1.8V VDD 4.5V
D031 with Schmitt Trigger buffer — — 0.2 VDD V2.0V VDD 5.5V
D032 MCLR ——0.2VDD V
VIH Input High Voltage
I/O ports:
D040 with TTL buffer 2.0 — — V 4.5V VDD 5.5V
D040A 0.25 VDD +
0.8
——V1.8V VDD 4.5V
D041 with Schmitt Trigger buffer 0.8 VDD ——V2.0V VDD 5.5V
D042 MCLR 0.8 VDD ——V
IIL Input Leakage Current(1)
D060 I/O ports — ± 5
± 5
± 125
± 1000
nA
nA
VSS VPIN VDD, Pin at high-
impedance at 85°C
125°C
D061 MCLR(2) —± 50± 200nAVSS VPIN VDD at 85°C
IPUR Weak Pull-up Current
D070* 25
25
100
140
200
300 A
VDD = 3.3V, VPIN = VSS
VDD = 5.0V, VPIN = VSS
VOL Output Low Voltage(3)
D080 I/O ports
——0.6V
IOL = 8mA, VDD = 5V
IOL = 6mA, VDD = 3.3V
IOL = 1.8mA, VDD = 1.8V
VOH Output High Voltage(3)
D090 I/O ports
VDD - 0.7 — — V
IOH = 3.5mA, VDD = 5V
IOH = 3mA, VDD = 3.3V
IOH = 1mA, VDD = 1.8V
Capacitive Loading Specs on Output Pins
D101A* CIO All I/O pins — — 50 pF
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
Note 1: Negative current is defined as current sourced by the pin.
2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent
normal operating conditions. Higher leakage current may be measured at different input voltages.
3: Including OSC2 in CLKOUT mode.
2011 Microchip Technology Inc. Preliminary DS41609A-page 339
PIC16(L)F1508/9
29.5 Memory Programming Requirements
DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +125°C
Param
No. Sym. Characteristic Min. Typ† Max. Units Conditions
Program Memory
Programming Specifications
D110 VIHH Voltage on MCLR/VPP pin 8.0 — 9.0 V (Note 2)
D111 IDDP Supply Current during
Programming
——10mA
D112 VBE VDD for Bulk Erase 2.7 — VDD max. V
D113 VPEW VDD for Write or Row Erase VDD min. — VDD max. V
D114 IPPPGM Current on MCLR/VPP during Erase/
Write
—1.0—mA
D115 IDDPGM Current on VDD during Erase/Write — 5.0 —mA
Program Flash Memory
D121 EPCell Endurance 10K ——E/W-40C to +85C (Note 1)
D122 VPR VDD for Read VDD min. — VDD max. V
D123 TIW Self-timed Write Cycle Time — 2 2.5 ms
D124 TRETD Characteristic Retention — 40 — Year Provided no other
specifications are violated
D125 EHEFC High-Endurance Flash Cell 100K — — E/W 0°C to +60°C lower byte,
last 128 addresses
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: Self-write and Block Erase.
2: Required only if single-supply programming is disabled.
PIC16(L)F1508/9
DS41609A-page 340 Preliminary 2011 Microchip Technology Inc.
29.6 Thermal Considerations
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +125°C
Param
No. Sym. Characteristic Typ. Units Conditions
TH01 JA Thermal Resistance Junction to Ambient 62.2 C/W 20-pin PDIP package
75.0 C/W 20-pin SOIC package
89.3 C/W 20-pin SSOP package
43.0 C/W 20-pin QFN 4X4mm package
TH02 JC Thermal Resistance Junction to Case 27.5 C/W 20-pin PDIP package
23.1 C/W 20-pin SOIC package
31.1 C/W 20-pin SSOP package
5.3 C/W 20-pin QFN 4X4mm package
TH03 TJMAX Maximum Junction Temperature 150 C
TH04 PD Power Dissipation — W PD = PINTERNAL + PI/O
TH05 PINTERNAL Internal Power Dissipation — W PINTERNAL = IDD x VDD(1)
TH06 PI/OI/O Power Dissipation — W PI/O = (IOL * VOL) + (IOH * (VDD - VOH))
TH07 PDER Derated Power — W PDER = PDMAX (TJ - TA)/JA(2)
Note 1: IDD is current to run the chip alone without driving any load on the output pins.
2: TA = Ambient Temperature
3: TJ = Junction Temperature
2011 Microchip Technology Inc. Preliminary DS41609A-page 341
PIC16(L)F1508/9
29.7 Timing Parameter Symbology
The timing parameter symbols have been created with
one of the following formats:
FIGURE 29-4: LOAD CONDITIONS
1. TppS2ppS
2. TppS
T
F Frequency T Time
Lowercase letters (pp) and their meanings:
pp
cc CCP1 osc CLKIN
ck CLKOUT rd RD
cs CS rw RD or WR
di SDIx sc SCKx
do SDO ss SS
dt Data in t0 T0CKI
io I/O PORT t1 T1CKI
mc MCLR wr WR
Uppercase letters and their meanings:
S
FFall PPeriod
HHigh RRise
I Invalid (High-impedance) V Valid
L Low Z High-impedance
V
SS
C
L
Legend: CL = 50 pF for all pins
Load Condition
Pin
PIC16(L)F1508/9
DS41609A-page 342 Preliminary 2011 Microchip Technology Inc.
29.8 AC Characteristics: PIC16(L)F1508/9-I/E
FIGURE 29-5: CLOCK TIMING
TABLE 29-1: CLOCK OSCILLATOR TIMING REQUIREMENTS
TABLE 29-2: OSCILLATOR PARAMETERS
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +125°C
Param
No. Sym. Characteristic Min. Typ† Max. Units Conditions
OS01 FOSC External CLKIN Frequency(1) DC — 0.5 MHz EC Oscillator mode (low)
DC — 4 MHz EC Oscillator mode (medium)
DC — 20 MHz EC Oscillator mode (high)
OS02 TOSC External CLKIN Period(1) 31.25 — ns EC mode
OS03 TCY Instruction Cycle Time(1) 125 — DC ns TCY = FOSC/4
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period. 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 con-
sumption. All devices are tested to operate at “min” values with an external clock applied to CLKIN pin. When an external
clock input is used, the “max” cycle time limit is “DC” (no clock) for all devices.
Standard Operating Conditions (unless otherwise stated)
Operating Temperature -40°C TA +125°C
Param
No. Sym. Characteristic Freq.
Tolerance Min. Typ† Max. Units Conditions
OS08 HFOSC Internal Calibrated HFINTOSC
Frequency(1)
10% — 16.0 — MHz 0°C TA +85°C
OS09 LFOSC Internal LFINTOSC Frequency — — 31 — kHz -40°C TA +125°C
OS10* TIOSC ST HFINTOSC
Wake-up from Sleep Start-up Time
——58s
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
Note 1: To ensure these oscillator frequency tolerances, VDD and VSS must be capacitively decoupled as close to the device as
possible. 0.1 F and 0.01 F values in parallel are recommended.
CLKIN
CLKOUT
Q4 Q1 Q2 Q3 Q4 Q1
OS02
OS03
(CLKOUT Mode)
Note 1: See Table 29-3.
OS11
OS12
2011 Microchip Technology Inc. Preliminary DS41609A-page 343
PIC16(L)F1508/9
FIGURE 29-6: CLKOUT AND I/O TIMING
TABLE 29-3: CLKOUT AND I/O TIMING PARAMETERS
Standard Operating Conditions (unless otherwise stated)
Operating Temperature -40°C TA +125°C
Param
No. Sym. Characteristic Min. Typ† Max. Units Conditions
OS11 TosH2ckL FOSC to CLKOUT (1) ——70nsVDD = 3.3-5.0V
OS12 TosH2ckH FOSC to CLKOUT (1) ——72nsVDD = 3.3-5.0V
OS13 TckL2ioV CLKOUT to Port out valid(1) ——20ns
OS14 TioV2ckH Port input valid before CLKOUT(1) TOSC + 200 ns — — ns
OS15 TosH2ioV Fosc (Q1 cycle) to Port out valid — 50 70* ns VDD = 3.3-5.0V
OS16 TosH2ioI Fosc (Q2 cycle) to Port input invalid
(I/O in hold time)
50 — — ns VDD = 3.3-5.0V
OS17 TioV2osH Port input valid to Fosc(Q2 cycle)
(I/O in setup time)
20 — — ns
OS18* TioR Port output rise time(2) —
—
15
40
32
72
ns VDD = 2.0V
VDD = 5.0V
OS19* TioF Port output fall time(2) —
—
28
15
55
30
ns VDD = 2.0V
VDD = 5.0V
OS20* Tinp INT pin input high or low time 25 — — ns
OS21* Tioc Interrupt-on-change new input level
time
25 — — ns
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25C unless otherwise stated.
Note 1: Measurements are taken in EC mode where CLKOUT output is 4 x TOSC.
FOSC
CLKOUT
I/O pin
(Input)
I/O pin
(Output)
Q4 Q1 Q2 Q3
OS11
OS19
OS13
OS15
OS18, OS19
OS20
OS21
OS17
OS16
OS14
OS12
OS18
Old Value New Value
Write Fetch Read ExecuteCycle
PIC16(L)F1508/9
DS41609A-page 344 Preliminary 2011 Microchip Technology Inc.
FIGURE 29-7: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP
TIMER TIMING
FIGURE 29-8: BROWN-OUT RESET TIMING AND CHARACTERISTICS
VDD
MCLR
Internal
POR
PWRT
Time-out
Internal Reset(1)
Watchdog Timer
33
30
31
34
I/O pins
34
Note 1: Asserted low.
Reset(1)
VBOR
VDD
(Device in Brown-out Reset) (Device not in Brown-out Reset)
33(1)
Note 1: 64 ms delay only if PWRTE bit in the Configuration Words is programmed to ‘0’.
2 ms delay if PWRTE = 0 and VREGEN = 1.
Reset
(due to BOR)
VBOR and VHYST
37
2011 Microchip Technology Inc. Preliminary DS41609A-page 345
PIC16(L)F1508/9
TABLE 29-4: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET PARAMETERS
FIGURE 29-9: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
Standard Operating Conditions (unless otherwise stated)
Operating Temperature -40°C TA +125°C
Param
No. Sym. Characteristic Min. Typ† Max. Units Conditions
30 TMCLMCLR Pulse Width (low) 2
5
—
—
—
—
s
s
VDD = 3.3-5V, -40°C to +85°C
VDD = 3.3-5V
31 TWDTLP Low-Power Watchdog Timer
Time-out Period
10 16 27 ms VDD = 3.3V-5V,
1:16 Prescaler used
33* TPWRT Power-up Timer Period, PWRTE =040 65 140 ms
34* TIOZ I/O high-impedance from MCLR Low
or Watchdog Timer Reset
——2.0s
35 VBOR Brown-out Reset Voltage 2.50
2.30
1.8
2.70
2.40
1.90
2.80
2.50
2.00
V
V
V
BORV = 0, high trip point
BORV = 1, low trip point
(PIC16F1508/9)
(PIC16LF1508/9)
36* VHYST Brown-out Reset Hysteresis 0 25 50 mV -40°C to +85°C
37* TBORDC Brown-out Reset DC Response
Time
135sVDD VBOR
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: To ensure these voltage tolerances, VDD and VSS must be capacitively decoupled as close to the device as
possible. 0.1 F and 0.01 F values in parallel are recommended.
T0CKI
T1CKI
40 41
42
45 46
47 49
TMR0 or
TMR1
PIC16(L)F1508/9
DS41609A-page 346 Preliminary 2011 Microchip Technology Inc.
TABLE 29-5: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
TABLE 29-6: PIC16(L)F1508/9 A/D CONVERTER (ADC) CHARACTERISTICS:
Standard Operating Conditions (unless otherwise stated)
Operating Temperature -40°C TA +125°C
Param
No. Sym. Characteristic Min. Typ† 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 Greater of:
20 or TCY + 40
N
— — ns N = prescale value
(2, 4, ..., 256)
45* TT1H T1CKI High
Time
Synchronous, No Prescaler 0.5 TCY + 20 — — ns
Synchronous,
with Prescaler
15 — — ns
Asynchronous 30 — — ns
46* TT1L T1CKI Low
Time
Synchronous, No Prescaler 0.5 TCY + 20 — — ns
Synchronous, with Prescaler 15 — — ns
Asynchronous 30 — — ns
47* TT1P T1CKI Input
Period
Synchronous Greater of:
30 or TCY + 40
N
— — ns N = prescale value
(1, 2, 4, 8)
Asynchronous 60 — — ns
49* TCKEZTMR1 Delay from External Clock Edge to Timer
Increment
2 TOSC —7 TOSC — Timers in Sync
mode
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
Note 1: For proper operation, the minimum value of the ADC positive voltage reference must be 1.8V or greater. When selecting
the FVR or the VREF+ pin as the source of the ADC positive voltage reference, be aware that the voltage must be 1.8V
or greater.
Standard Operating Conditions (unless otherwise stated)
Operating temperature Tested at 25°C
Param
No. Sym. Characteristic Min. Typ† Max. Units Conditions
AD01 NRResolution — — 10 bit
AD02 EIL Integral Error — — ±1.7 LSb VREF = 3.0V
AD03 EDL Differential Error — — ±1 LSb No missing codes
VREF = 3.0V
AD04 EOFF Offset Error — — ±2.5 LSb VREF = 3.0V
AD05 EGN Gain Error — — ±2.0 LSb VREF = 3.0V
AD06 VREF Reference Voltage(3) 1.8 — VDD VVREF = (VREF+ minus VREF-) (NOTE 5)
AD07 VAIN Full-Scale Range VSS —VREF V
AD08 ZAIN Recommended Impedance of
Analog Voltage Source
—— 10kCan go higher if external 0.01F capacitor is
present on input pin.
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
Note 1: Total Absolute Error includes integral, differential, offset and gain errors.
2: The A/D conversion result never decreases with an increase in the input voltage and has no missing codes.
3: ADC VREF is from external VREF+ pin, VDD pin, whichever is selected as reference input.
4: When ADC is off, it will not consume any current other than leakage current. The power-down current specification
includes any such leakage from the ADC module.
5: FVR voltage selected must be 2.048V or 4.096V.
2011 Microchip Technology Inc. Preliminary DS41609A-page 347
PIC16(L)F1508/9
TABLE 29-7: PIC16(L)F1508/9 A/D CONVERSION REQUIREMENTS
FIGURE 29-10: PIC16(L)F1508/9 A/D CONVERSION TIMING (NORMAL MODE)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +125°C
Param
No. Sym. Characteristic Min. Typ† Max. Units Conditions
AD130* TAD A/D Clock Period 1.0 — 9.0 sTOSC-based
A/D Internal FRC Oscillator
Period
1.0 1.6 6.0 s ADCS<1:0> = 11 (ADFRC mode)
AD131 TCNV Conversion Time (not including
Acquisition Time)(1)
—11—TAD Set GO/DONE bit to conversion
complete
AD132* TACQ Acquisition Time — 5.0 — s
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
Note 1: The ADRES register may be read on the following TCY cycle.
AD131
AD130
BSF ADCON0, GO
Q4
A/D CLK
A/D Data
ADRES
ADIF
GO
Sample
OLD_DATA
Sampling Stopped
DONE
NEW_DATA
987 3210
Note 1: If the A/D clock source is selected as FRC, a time of TCY is added before the A/D clock starts. This allows the
SLEEP instruction to be executed.
1 TCY
6
AD134 (TOSC/2(1))
1 TCY
AD132
PIC16(L)F1508/9
DS41609A-page 348 Preliminary 2011 Microchip Technology Inc.
FIGURE 29-11: PIC16(L)F1508/9 A/D CONVERSION TIMING (SLEEP MODE)
AD132
AD131
AD130
BSF ADCON0, GO
Q4
A/D CLK
A/D Data
ADRES
ADIF
GO
Sample
OLD_DATA
Sampling Stopped
DONE
NEW_DATA
9 7 3210
Note 1: If the A/D clock source is selected as FRC, a time of TCY is added before the A/D clock starts. This allows the
SLEEP instruction to be executed.
AD134
6
8
1 TCY
(TOSC/2 + TCY(1))
1 TCY
2011 Microchip Technology Inc. Preliminary DS41609A-page 349
PIC16(L)F1508/9
TABLE 29-8: COMPARATOR SPECIFICATIONS
TABLE 29-9: DIGITAL-TO-ANALOG CONVERTER (DAC) SPECIFICATIONS
Operating Conditions: 1.8V < VDD < 5.5V, -40°C < TA < +125°C (unless otherwise stated).
Param
No. Sym. Characteristics Min. Typ. Max. Units Comments
CM01 VIOFF Input Offset Voltage — ±7.5 ±60 mV
CM02 VICM Input Common Mode Voltage 0 — VDD V
CM04A
TRESP
Response Time Rising Edge — 400 800 ns High-Power mode
(Note 1)
CM04B Response Time Falling Edge — 200 400 ns High-Power mode
(Note 1)
CM04C Response Time Rising Edge — 1200 — ns Low-Power mode
(Note 1)
CM04D Response Time Falling Edge — 550 — ns Low-Power mode
(Note 1)
CM05 TMC2OV Comparator Mode Change to
Output Valid*
——10s
CM06 CHYSTER Comparator Hysteresis — 65 — mV Note 2
* These parameters are characterized but not tested.
Note 1: Response time measured with one comparator input at VDD/2, while the other input transitions
from VSS to VDD.
2: Comparator Hysteresis is available when the CxHYS bit of the CMxCON0 register is enabled.
Operating Conditions: 1.8V < VDD < 5.5V, -40°C < TA < +125°C (unless otherwise stated).
Param
No. Sym. Characteristics Min. Typ. Max. Units Comments
DAC01* CLSB Step Size(2) —VDD/32 — V
DAC02* CACC Absolute Accuracy — — 1/2 LSb
DAC03* CRUnit Resistor Value (R) — 5K —
DAC04* CST Settling Time(1) ——10s
* These parameters are characterized but not tested.
Legend: TBD = To Be Determined
Note 1: Settling time measured while DACR<4:0> transitions from ‘0000’ to ‘1111’.
PIC16(L)F1508/9
DS41609A-page 350 Preliminary 2011 Microchip Technology Inc.
FIGURE 29-12: USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING
TABLE 29-10: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS
FIGURE 29-13: USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING
TABLE 29-11: USART SYNCHRONOUS RECEIVE REQUIREMENTS
Standard Operating Conditions (unless otherwise stated)
Operating Temperature -40°C TA +125°C
Param.
No. Symbol Characteristic Min. Max. Units Conditions
US120 TCKH2DTV SYNC XMIT (Master and Slave)
Clock high to data-out valid
3.0-5.5V — 80 ns
1.8-5.5V — 100 ns
US121 TCKRF Clock out rise time and fall time
(Master mode)
3.0-5.5V — 45 ns
1.8-5.5V — 50 ns
US122 TDTRF Data-out rise time and fall time 3.0-5.5V — 45 ns
1.8-5.5V — 50 ns
Standard Operating Conditions (unless otherwise stated)
Operating Temperature -40°C TA +125°C
Param.
No. Symbol Characteristic Min. Max. Units Conditions
US125 TDTV2CKL SYNC RCV (Master and Slave)
Data-hold before CK (DT hold time) 10 — ns
US126 T
CKL2DTL Data-hold after CK (DT hold time) 15 — ns
Note: Refer to Figure 29-4 for load conditions.
US121 US121
US120 US122
CK
DT
Note: Refer to Figure 29-4 for load conditions.
US125
US126
CK
DT
2011 Microchip Technology Inc. Preliminary DS41609A-page 351
PIC16(L)F1508/9
FIGURE 29-14: SPI MASTER MODE TIMING (CKE = 0, SMP = 0)
FIGURE 29-15: SPI MASTER MODE TIMING (CKE = 1, SMP = 1)
SS
SCK
(CKP = 0)
SCK
(CKP = 1)
SDO
SDI
SP70
SP71 SP72
SP73
SP74
SP75, SP76
SP78
SP79
SP80
SP79
SP78
MSb LSb
bit 6 - - - - - -1
MSb In LSb In
bit 6 - - - -1
Note: Refer to Figure 29-4 for load conditions.
SS
SCK
(CKP = 0)
SCK
(CKP = 1)
SDO
SDI
SP81
SP71 SP72
SP74
SP75, SP76
SP78
SP80
MSb
SP79
SP73
MSb In
bit 6 - - - - - -1
LSb In
bit 6 - - - -1
LSb
Note: Refer to Figure 29-4 for load conditions.
PIC16(L)F1508/9
DS41609A-page 352 Preliminary 2011 Microchip Technology Inc.
FIGURE 29-16: SPI SLAVE MODE TIMING (CKE = 0)
FIGURE 29-17: SPI SLAVE MODE TIMING (CKE = 1)
SS
SCK
(CKP = 0)
SCK
(CKP = 1)
SDO
SDI
SP70
SP71 SP72
SP73
SP74
SP75, SP76 SP77
SP78
SP79
SP80
SP79
SP78
MSb LSb
bit 6 - - - - - -1
MSb In bit 6 - - - -1 LSb In
SP83
Note: Refer to Figure 29-4 for load conditions.
SS
SCK
(CKP = 0)
SCK
(CKP = 1)
SDO
SDI
SP70
SP71 SP72
SP82
SP74
SP75, SP76
MSb bit 6 - - - - - -1 LSb
SP77
MSb In bit 6 - - - -1 LSb In
SP80
SP83
Note: Refer to Figure 29-4 for load conditions.
2011 Microchip Technology Inc. Preliminary DS41609A-page 353
PIC16(L)F1508/9
TABLE 29-12: SPI MODE REQUIREMENTS
Param
No. Symbol Characteristic Min. Typ† Max. Units Conditions
SP70* TSSL2SCH,
TSSL2SCL
SS to SCK or SCK input TCY ——ns
SP71* TSCH SCK input high time (Slave mode) TCY + 20 — — ns
SP72* TSCL SCK input low time (Slave mode) TCY + 20 — — ns
SP73* TDIV2SCH,
TDIV2SCL
Setup time of SDI data input to SCK edge 100 — — ns
SP74* TSCH2DIL,
TSCL2DIL
Hold time of SDI data input to SCK edge 100 — — ns
SP75* TDOR SDO data output rise time 3.0-5.5V — 10 25 ns
1.8-5.5V — 25 50 ns
SP76* TDOF SDO data output fall time — 10 25 ns
SP77* TSSH2DOZSS to SDO output high-impedance 10 — 50 ns
SP78* TSCR SCK output rise time
(Master mode)
3.0-5.5V — 10 25 ns
1.8-5.5V — 25 50 ns
SP79* TSCF SCK output fall time (Master mode) — 10 25 ns
SP80* TSCH2DOV,
TSCL2DOV
SDO data output valid after
SCK edge
3.0-5.5V — — 50 ns
1.8-5.5V — — 145 ns
SP81* TDOV2SCH,
TDOV2SCL
SDO data output setup to SCK edge Tcy — — ns
SP82* TSSL2DOV SDO data output valid after SS edge — — 50 ns
SP83* TSCH2SSH,
TSCL2SSH
SS after SCK edge 1.5TCY + 40 — — ns
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
PIC16(L)F1508/9
DS41609A-page 354 Preliminary 2011 Microchip Technology Inc.
FIGURE 29-18: I2C™ BUS START/STOP BITS TIMING
TABLE 29-13: I2C™ BUS START/STOP BITS REQUIREMENTS
FIGURE 29-19: I2C™ BUS DATA TIMING
Param
No. Symbol Characteristic Min. Typ Max. Units Conditions
SP90* TSU:STA Start condition 100 kHz mode 4700 — — ns Only relevant for Repeated
Start condition
Setup time 400 kHz mode 600 — —
SP91* THD:STA Start condition 100 kHz mode 4000 — — ns After this period, the first
clock pulse is generated
Hold time 400 kHz mode 600 — —
SP92* TSU:STO Stop condition 100 kHz mode 4700 — — ns
Setup time 400 kHz mode 600 — —
SP93 THD:STO Stop condition 100 kHz mode 4000 — — ns
Hold time 400 kHz mode 600 — —
* These parameters are characterized but not tested.
Note: Refer to Figure 29-4 for load conditions.
SP91
SP92
SP93
SCL
SDA
Start
Condition
Stop
Condition
SP90
Note: Refer to Figure 29-4 for load conditions.
SP90
SP91 SP92
SP100
SP101
SP103
SP106 SP107
SP109 SP109
SP110
SP102
SCL
SDA
In
SDA
Out
2011 Microchip Technology Inc. Preliminary DS41609A-page 355
PIC16(L)F1508/9
TABLE 29-14: I2C™ BUS DATA REQUIREMENTS
Param.
No. Symbol Characteristic Min. Max. Units Conditions
SP100* THIGH Clock high time 100 kHz mode 4.0 — s Device must operate at a
minimum of 1.5 MHz
400 kHz mode 0.6 — s Device must operate at a
minimum of 10 MHz
SSP module 1.5TCY —
SP101* TLOW Clock low time 100 kHz mode 4.7 — s Device must operate at a
minimum of 1.5 MHz
400 kHz mode 1.3 — s Device must operate at a
minimum of 10 MHz
SSP module 1.5TCY —
SP102* TRSDA and SCL rise
time
100 kHz mode — 1000 ns
400 kHz mode 20 + 0.1CB300 ns CB is specified to be from
10-400 pF
SP103* TFSDA and SCL fall
time
100 kHz mode — 250 ns
400 kHz mode 20 + 0.1CB250 ns CB is specified to be from
10-400 pF
SP106* THD:DAT Data input hold time 100 kHz mode 0 — ns
400 kHz mode 0 0.9 s
SP107* TSU:DAT Data input setup
time
100 kHz mode 250 — ns (Note 2)
400 kHz mode 100 — ns
SP109* TAA Output valid from
clock
100 kHz mode — 3500 ns (Note 1)
400 kHz mode — — ns
SP110* TBUF Bus free time 100 kHz mode 4.7 — s Time the bus must be free
before a new transmission
can start
400 kHz mode 1.3 — s
SP111 CBBus capacitive loading — 400 pF
* These parameters are characterized but not tested.
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 SCL to avoid unintended generation of Start or Stop conditions.
2: A Fast mode (400 kHz) I2C™ bus device can be used in a Standard mode (100 kHz) I2C bus system, but
the requirement T
SU:DAT 250 ns must then be met. This will automatically be the case if the device does
not stretch the low period of the SCL signal. If such a device does stretch the low period of the SCL signal,
it must output the next data bit to the SDA line TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to
the Standard mode I2C bus specification), before the SCL line is released.
PIC16(L)F1508/9
DS41609A-page 356 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 357
PIC16(L)F1508/9
30.0 DC AND AC
CHARACTERISTICS GRAPHS
AND CHARTS
Graphs and charts are not available at this time.
PIC16(L)F1508/9
DS41609A-page 358 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 359
PIC16(L)F1508/9
31.0 DEVELOPMENT SUPPORT
The PIC® microcontrollers and dsPIC® digital signal
controllers are supported with a full range of software
and hardware development tools:
• Integrated Development Environment
- MPLAB® IDE Software
• Compilers/Assemblers/Linkers
- MPLAB C Compiler for Various Device
Families
- HI-TECH C® for Various Device Families
- MPASMTM Assembler
-MPLINK
TM Object Linker/
MPLIBTM Object Librarian
- MPLAB Assembler/Linker/Librarian for
Various Device Families
• Simulators
- MPLAB SIM Software Simulator
•Emulators
- MPLAB REAL ICE™ In-Circuit Emulator
• In-Circuit Debuggers
- MPLAB ICD 3
- PICkit™ 3 Debug Express
• Device Programmers
- PICkit™ 2 Programmer
- MPLAB PM3 Device Programmer
• Low-Cost Demonstration/Development Boards,
Evaluation Kits, and Starter Kits
31.1 MPLAB Integrated Development
Environment Software
The MPLAB IDE software brings an ease of software
development previously unseen in the 8/16/32-bit
microcontroller 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)
- In-Circuit 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
• 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
IAR C Compilers
The MPLAB IDE allows you to:
• Edit your source files (either C or assembly)
• One-touch compile or assemble, and download to
emulator and simulator tools (automatically
updates all project information)
• Debug using:
- Source files (C or assembly)
- Mixed C and assembly
- 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.
PIC16(L)F1508/9
DS41609A-page 360 Preliminary 2011 Microchip Technology Inc.
31.2 MPLAB C Compilers for Various
Device Families
The MPLAB C Compiler code development systems
are complete ANSI C compilers for Microchip’s PIC18,
PIC24 and PIC32 families of microcontrollers and the
dsPIC30 and dsPIC33 families of digital signal control-
lers. These compilers provide powerful integration
capabilities, superior code optimization and ease of
use.
For easy source level debugging, the compilers provide
symbol information that is optimized to the MPLAB IDE
debugger.
31.3 HI-TECH C for Various Device
Families
The HI-TECH C Compiler code development systems
are complete ANSI C compilers for Microchip’s PIC
family of microcontrollers and the dsPIC family of digital
signal controllers. These compilers provide powerful
integration capabilities, omniscient code generation
and ease of use.
For easy source level debugging, the compilers provide
symbol information that is optimized to the MPLAB IDE
debugger.
The compilers include a macro assembler, linker, pre-
processor, and one-step driver, and can run on multiple
platforms.
31.4 MPASM Assembler
The MPASM Assembler is a full-featured, universal
macro assembler for PIC10/12/16/18 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
31.5 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
31.6 MPLAB Assembler, Linker and
Librarian for Various Device
Families
MPLAB Assembler produces relocatable machine
code from symbolic assembly language for PIC24,
PIC32 and dsPIC devices. MPLAB 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 device instruction set
• Support for fixed-point and floating-point data
• Command line interface
• Rich directive set
• Flexible macro language
• MPLAB IDE compatibility
2011 Microchip Technology Inc. Preliminary DS41609A-page 361
PIC16(L)F1508/9
31.7 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 C Compilers,
and the MPASM and MPLAB Assemblers. The soft-
ware simulator offers the flexibility to develop and
debug code outside of the hardware laboratory envi-
ronment, making it an excellent, economical software
development tool.
31.8 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 emulator 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 in-
circuit debugger systems (RJ11) or with the new high-
speed, noise tolerant, Low-Voltage Differential Signal
(LVDS) interconnection (CAT5).
The emulator is field upgradable through future firmware
downloads in MPLAB IDE. In upcoming releases of
MPLAB IDE, new devices will be supported, and new
features will be added. MPLAB REAL ICE offers
significant advantages over competitive emulators
including low-cost, full-speed emulation, run-time
variable watches, trace analysis, complex breakpoints, a
ruggedized probe interface and long (up to three meters)
interconnection cables.
31.9 MPLAB ICD 3 In-Circuit Debugger
System
MPLAB ICD 3 In-Circuit Debugger System is Micro-
chip's most cost effective high-speed hardware
debugger/programmer for Microchip Flash Digital Sig-
nal Controller (DSC) and microcontroller (MCU)
devices. It debugs and programs PIC® Flash microcon-
trollers and dsPIC® DSCs with the powerful, yet easy-
to-use graphical user interface of MPLAB Integrated
Development Environment (IDE).
The MPLAB ICD 3 In-Circuit Debugger probe is con-
nected to the design engineer's PC using a high-speed
USB 2.0 interface and is connected to the target with a
connector compatible with the MPLAB ICD 2 or MPLAB
REAL ICE systems (RJ-11). MPLAB ICD 3 supports all
MPLAB ICD 2 headers.
31.10 PICkit 3 In-Circuit Debugger/
Programmer and
PICkit 3 Debug Express
The MPLAB PICkit 3 allows debugging and program-
ming of PIC® and dsPIC® Flash microcontrollers at a
most affordable price point using the powerful graphical
user interface of the MPLAB Integrated Development
Environment (IDE). The MPLAB PICkit 3 is connected
to the design engineer's PC using a full speed USB
interface and can be connected to the target via an
Microchip debug (RJ-11) connector (compatible with
MPLAB ICD 3 and MPLAB REAL ICE). The connector
uses two device I/O pins and the reset line to imple-
ment in-circuit debugging and In-Circuit Serial Pro-
gramming™.
The PICkit 3 Debug Express include the PICkit 3, demo
board and microcontroller, hookup cables and CDROM
with user’s guide, lessons, tutorial, compiler and
MPLAB IDE software.
PIC16(L)F1508/9
DS41609A-page 362 Preliminary 2011 Microchip Technology Inc.
31.11 PICkit 2 Development
Programmer/Debugger and
PICkit 2 Debug Express
The PICkit™ 2 Development Programmer/Debugger is
a low-cost development tool with an easy to use inter-
face for programming and debugging Microchip’s Flash
families of microcontrollers. The full featured
Windows® programming interface supports baseline
(PIC10F, PIC12F5xx, PIC16F5xx), midrange
(PIC12F6xx, PIC16F), PIC18F, PIC24, dsPIC30,
dsPIC33, and PIC32 families of 8-bit, 16-bit, and 32-bit
microcontrollers, and many Microchip Serial EEPROM
products. With Microchip’s powerful MPLAB Integrated
Development Environment (IDE) the PICkit™ 2
enables in-circuit debugging on most PIC® microcon-
trollers. In-Circuit-Debugging runs, halts and single
steps the program while the PIC microcontroller is
embedded in the application. When halted at a break-
point, the file registers can be examined and modified.
The PICkit 2 Debug Express include the PICkit 2, demo
board and microcontroller, hookup cables and CDROM
with user’s guide, lessons, tutorial, compiler and
MPLAB IDE software.
31.12 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 MMC card for file
storage and data applications.
31.13 Demonstration/Development
Boards, Evaluation Kits, and
Starter Kits
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.
Also available are starter kits that contain everything
needed to experience the specified device. This usually
includes a single application and debug capability, all
on one board.
Check the Microchip web page (www.microchip.com)
for the complete list of demonstration, development
and evaluation kits.
2011 Microchip Technology Inc. Preliminary DS41609A-page 363
PIC16(L)F1508/9
32.0 PACKAGING INFORMATION
32.1 Package Marking Information
*Standard PICmicro® device marking consists of Microchip part number, year code, week code and
traceability code. For PICmicro device marking beyond this, certain price adders apply. Please check
with your Microchip Sales Office. For QTP devices, any special marking adders are included in QTP
price.
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
20-Lead PDIP (300 mil) Example
XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXX
YYWWNNN
PIC16F1508
-E/P
3
e
1120123
20-Lead SOIC (7.50 mm) Example
PIC16F1508
-E/SO
3
e
1120123
PIC16(L)F1508/9
DS41609A-page 364 Preliminary 2011 Microchip Technology Inc.
32.2 Package Marking Information
20-Lead SSOP (5.30 mm) Example
20-Lead QFN (4x4x0.9 mm) Example
PIN 1 PIN 1
-E/SS
3
e
1120123
PIC16F1508
PIC16
F1508
-E/ML
120123
3
e
2011 Microchip Technology Inc. Preliminary DS41609A-page 365
PIC16(L)F1508/9
32.3 Package Details
The following sections give the technical details of the packages.
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Note: For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
2011 Microchip Technology Inc. Preliminary DS41609A-page 367
PIC16(L)F1508/9
Note: For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
PIC16(L)F1508/9
DS41609A-page 368 Preliminary 2011 Microchip Technology Inc.
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2011 Microchip Technology Inc. Preliminary DS41609A-page 369
PIC16(L)F1508/9
Note: For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
PIC16(L)F1508/9
DS41609A-page 370 Preliminary 2011 Microchip Technology Inc.
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2011 Microchip Technology Inc. Preliminary DS41609A-page 371
PIC16(L)F1508/9
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DS41609A-page 372 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 373
PIC16(L)F1508/9
APPENDIX A: DATA SHEET
REVISION HISTORY
Revision A
Original release (10/2011).
PIC16(L)F1508/9
DS41609A-page 374 Preliminary 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. Preliminary DS41609A-page 375
PIC16(L)F1508/9
INDEX
A
A/D
Specifications.................................................... 346, 347
Absolute Maximum Ratings .............................................. 329
AC Characteristics
Industrial and Extended ............................................ 342
Load Conditions ........................................................ 341
ACKSTAT ......................................................................... 218
ACKSTAT Status Flag ...................................................... 218
ADC .................................................................................. 135
Acquisition Requirements ......................................... 146
Associated registers.................................................. 148
Block Diagram........................................................... 135
Calculating Acquisition Time..................................... 146
Channel Selection..................................................... 136
Configuration............................................................. 136
Configuring Interrupt ................................................. 140
Conversion Clock...................................................... 136
Conversion Procedure .............................................. 140
Internal Sampling Switch (RSS) Impedance.............. 146
Interrupts................................................................... 138
Operation .................................................................. 139
Operation During Sleep ............................................ 139
Port Configuration..................................................... 136
Reference Voltage (VREF)......................................... 136
Source Impedance.................................................... 146
Starting an A/D Conversion ...................................... 138
ADCON0 Register....................................................... 29, 141
ADCON1 Register....................................................... 29, 142
ADCON2 Register............................................................. 143
ADDFSR ........................................................................... 319
ADDWFC .......................................................................... 319
ADRESH Register............................................................... 29
ADRESH Register (ADFM = 0)......................................... 144
ADRESH Register (ADFM = 1)......................................... 145
ADRESL Register (ADFM = 0).......................................... 144
ADRESL Register (ADFM = 1).......................................... 145
Alternate Pin Function....................................................... 112
Analog-to-Digital Converter. See ADC
ANSELA Register ............................................................. 115
ANSELB Register ............................................................. 119
ANSELC Register ............................................................. 123
APFCON Register............................................................. 112
Assembler
MPASM Assembler................................................... 360
Automatic Context Saving................................................... 77
B
Bank 10............................................................................... 32
Bank 11............................................................................... 32
Bank 12............................................................................... 32
Bank 13............................................................................... 32
Bank 2................................................................................. 30
Bank 3................................................................................. 30
Bank 30............................................................................... 33
Bank 4................................................................................. 31
Bank 5................................................................................. 31
Bank 6................................................................................. 31
Bank 7................................................................................. 31
Bank 8................................................................................. 31
Bank 9................................................................................. 31
BAUDCON Register.......................................................... 248
BF ............................................................................. 218, 220
BF Status Flag.......................................................... 218, 220
Block Diagrams
ADC .......................................................................... 135
ADC Transfer Function............................................. 147
Analog Input Model........................................... 147, 158
Block Diagrams
PIC16(L)1508/9 .................................................... 5
Clock Source .............................................................. 50
Comparator............................................................... 154
Crystal Operation.................................................. 52, 53
Digital-to-Analog Converter (DAC) ........................... 150
EUSART Receive..................................................... 238
EUSART Transmit .................................................... 237
External RC Mode ...................................................... 53
Fail-Safe Clock Monitor (FSCM)................................. 60
Generic I/O Port........................................................ 111
Interrupt Logic............................................................. 73
NCO.......................................................................... 288
On-Chip Reset Circuit................................................. 65
PIC16(L)F1508/9 ........................................................ 10
PWM......................................................................... 265
Resonator Operation .................................................. 52
Timer0 ...................................................................... 163
Timer1 ...................................................................... 167
Timer1 Gate.............................................. 172, 173, 174
Timer2 ...................................................................... 179
Voltage Reference.................................................... 131
Voltage Reference Output Buffer Example .............. 150
BORCON Register.............................................................. 67
BRA .................................................................................. 320
Break Character (12-bit) Transmit and Receive ............... 257
Brown-out Reset (BOR)...................................................... 67
Specifications ........................................................... 345
Timing and Characteristics ....................................... 344
C
C Compilers
MPLAB C18.............................................................. 360
CALL................................................................................. 321
CALLW ............................................................................. 321
CLCDATA Register........................................................... 285
CLCxCON Register .......................................................... 277
CLCxGLS0 Register ......................................................... 281
CLCxGLS1 Register ......................................................... 282
CLCxGLS2 Register ......................................................... 283
CLCxGLS3 Register ......................................................... 284
CLCxPOL Register ........................................................... 278
CLCxSEL0 Register.......................................................... 279
Clock Accuracy with Asynchronous Operation ................. 246
Clock Sources
External Modes........................................................... 51
EC ...................................................................... 51
HS ...................................................................... 51
LP ....................................................................... 51
OST .................................................................... 52
RC ...................................................................... 53
XT....................................................................... 51
Internal Modes............................................................ 54
HFINTOSC ......................................................... 54
Internal Oscillator Clock Switch Timing .............. 55
LFINTOSC.......................................................... 54
Clock Switching .................................................................. 57
CMOUT Register .............................................................. 160
CMxCON0 Register.......................................................... 159
PIC16(L)F1508/9
DS41609A-page 376 Preliminary 2011 Microchip Technology Inc.
CMxCON1 Register .......................................................... 160
Code Examples
A/D Conversion.........................................................140
Initializing PORTA.....................................................113
Writing to Flash Program Memory ............................104
Comparator
Associated Registers ................................................ 161
Operation .................................................................. 153
Comparator Module .......................................................... 153
Cx Output State Versus Input Conditions ................. 155
Comparator Specifications................................................ 349
Comparators
C2OUT as T1 Gate ...................................................169
Complementary Waveform Generator (CWG) .......... 297, 298
CONFIG1 Register.............................................................. 44
CONFIG2 Register.............................................................. 45
Core Function Register ....................................................... 28
Customer Change Notification Service ............................. 381
Customer Notification Service........................................... 381
Customer Support ............................................................. 381
CWG
Auto-shutdown Control .............................................304
Clock Source............................................................. 300
Output Control...........................................................300
Selectable Input Sources .......................................... 300
CWGxCON0 Register .......................................................307
CWGxCON1 Register .......................................................308
CWGxCON2 Register .......................................................309
CWGxDBF Register.......................................................... 310
CWGxDBR Register.......................................................... 310
D
DACCON0 (Digital-to-Analog Converter Control 0)
Register..................................................................... 152
DACCON1 (Digital-to-Analog Converter Control 1)
Register..................................................................... 152
Data Memory....................................................................... 20
DC and AC Characteristics ............................................... 357
DC Characteristics
Extended and Industrial ............................................ 338
Industrial and Extended ............................................ 331
Development Support ....................................................... 359
Device Configuration........................................................... 43
Code Protection .......................................................... 46
Configuration Word .....................................................43
User ID..................................................................46, 47
Device ID Register ..............................................................47
Device Overview ............................................................. 9, 91
Digital-to-Analog Converter (DAC).................................... 149
Associated Registers ................................................ 152
Effects of a Reset...................................................... 150
Specifications............................................................ 349
E
Effects of Reset
PWM mode ...............................................................267
Electrical Specifications .................................................... 329
Enhanced Mid-Range CPU................................................. 15
Enhanced Universal Synchronous Asynchronous
Receiver Transmitter (EUSART)............................... 237
Errata .................................................................................... 8
EUSART............................................................................ 237
Associated Registers
Baud Rate Generator........................................ 250
Asynchronous Mode ................................................. 239
12-bit Break Transmit and Receive................... 257
Associated Registers
Receive .................................................... 245
Transmit.................................................... 241
Auto-Wake-up on Break ................................... 255
Baud Rate Generator (BRG) ............................ 249
Clock Accuracy................................................. 246
Receiver ........................................................... 242
Setting up 9-bit Mode with Address Detect ...... 244
Transmitter ....................................................... 239
Baud Rate Generator (BRG)
Auto Baud Rate Detect..................................... 254
Baud Rate Error, Calculating............................ 249
Baud Rates, Asynchronous Modes .................. 251
Formulas........................................................... 250
High Baud Rate Select (BRGH Bit) .................. 249
Synchronous Master Mode............................... 258, 262
Associated Registers
Receive .................................................... 261
Transmit.................................................... 259
Reception ......................................................... 260
Transmission .................................................... 258
Synchronous Slave Mode
Associated Registers
Receive .................................................... 263
Transmit.................................................... 262
Reception ......................................................... 263
Transmission .................................................... 262
Extended Instruction Set
ADDFSR................................................................... 319
F
Fail-Safe Clock Monitor ...................................................... 60
Fail-Safe Condition Clearing....................................... 60
Fail-Safe Detection ..................................................... 60
Fail-Safe Operation..................................................... 60
Reset or Wake-up from Sleep .................................... 60
Firmware Instructions ....................................................... 315
Fixed Voltage Reference (FVR)........................................ 131
Associated Registers................................................ 132
Flash Program Memory ...................................................... 95
Associated Registers................................................ 110
Configuration Word w/ Flash Program Memory........ 110
Erasing ....................................................................... 99
Modifying .................................................................. 105
Write Verify ............................................................... 107
Writing ...................................................................... 101
FSR Register ...................................................................... 28
FVRCON (Fixed Voltage Reference Control) Register..... 132
I
I2C Mode (MSSPx)
Acknowledge Sequence Timing ............................... 222
Bus Collision
During a Repeated Start Condition................... 227
During a Stop Condition ................................... 228
Effects of a Reset ..................................................... 223
I2C Clock Rate w/BRG.............................................. 230
Master Mode
Operation.......................................................... 214
Reception ......................................................... 220
Start Condition Timing .............................. 216, 217
Transmission .................................................... 218
Multi-Master Communication, Bus Collision and
Arbitration ......................................................... 223
Multi-Master Mode.................................................... 223
Read/Write Bit Information (R/W Bit)........................ 198
2011 Microchip Technology Inc. Preliminary DS41609A-page 377
PIC16(L)F1508/9
Slave Mode
Transmission .................................................... 204
Sleep Operation........................................................ 223
Stop Condition Timing............................................... 222
INDF Register ..................................................................... 28
Indirect Addressing ............................................................. 38
Instruction Format ............................................................. 316
Instruction Set ................................................................... 315
ADDLW ..................................................................... 319
ADDWF..................................................................... 319
ADDWFC .................................................................. 319
ANDLW ..................................................................... 319
ANDWF..................................................................... 319
BRA........................................................................... 320
CALL ......................................................................... 321
CALLW...................................................................... 321
LSLF ......................................................................... 323
LSRF......................................................................... 323
MOVF........................................................................ 323
MOVIW ..................................................................... 324
MOVLB ..................................................................... 324
MOVWI ..................................................................... 325
OPTION .................................................................... 325
RESET ...................................................................... 325
SUBWFB................................................................... 327
TRIS.......................................................................... 328
BCF........................................................................... 320
BSF........................................................................... 320
BTFSC ...................................................................... 320
BTFSS ...................................................................... 320
CALL ......................................................................... 321
CLRF......................................................................... 321
CLRW ....................................................................... 321
CLRWDT................................................................... 321
COMF ....................................................................... 321
DECF ........................................................................ 321
DECFSZ.................................................................... 322
GOTO ....................................................................... 322
INCF.......................................................................... 322
INCFSZ..................................................................... 322
IORLW ...................................................................... 322
IORWF ...................................................................... 322
MOVLW .................................................................... 324
MOVWF .................................................................... 324
NOP .......................................................................... 325
RETFIE ..................................................................... 326
RETLW ..................................................................... 326
RETURN ................................................................... 326
RLF ........................................................................... 326
RRF........................................................................... 327
SLEEP ...................................................................... 327
SUBLW ..................................................................... 327
SUBWF..................................................................... 327
SWAPF ..................................................................... 328
XORLW..................................................................... 328
XORWF..................................................................... 328
INTCON Register................................................................ 78
Internal Oscillator Block
INTOSC
Specifications.................................................... 342
Internal Sampling Switch (RSS) Impedance...................... 146
Internet Address................................................................ 381
Interrupt-On-Change ......................................................... 125
Associated Registers ................................................ 129
Interrupts............................................................................. 73
ADC .......................................................................... 140
Associated registers w/ Interrupts .............................. 85
Configuration Word w/ Clock Sources........................ 63
TMR1........................................................................ 171
INTOSC Specifications..................................................... 342
IOCAF Register ................................................................ 127
IOCAN Register................................................................ 127
IOCAP Register ................................................................ 127
IOCBF Register ................................................................ 128
IOCBN Register................................................................ 128
IOCBP Register ................................................................ 128
L
LATA Register .......................................................... 115, 122
LATB Register .................................................................. 119
Load Conditions................................................................ 341
LSLF ................................................................................. 323
LSRF ................................................................................ 323
M
Master Synchronous Serial Port. See MSSPx
MCLR ................................................................................. 68
Internal........................................................................ 68
Memory Organization ......................................................... 17
Data ............................................................................ 20
Program...................................................................... 17
Microchip Internet Web Site.............................................. 381
MOVIW ............................................................................. 324
MOVLB ............................................................................. 324
MOVWI ............................................................................. 325
MPLAB ASM30 Assembler, Linker, Librarian ................... 360
MPLAB Integrated Development Environment Software.. 359
MPLAB PM3 Device Programmer .................................... 362
MPLAB REAL ICE In-Circuit Emulator System ................ 361
MPLINK Object Linker/MPLIB Object Librarian ................ 360
MSSPx.............................................................................. 183
SPI Mode.................................................................. 186
SSPxBUF Register................................................... 189
SSPxSR Register ..................................................... 189
N
NCO
Associated registers ................................................. 296
NCOxACCH Register ....................................................... 294
NCOxACCL Register........................................................ 294
NCOxACCU Register ....................................................... 294
NCOxCLK Register........................................................... 293
NCOxCON Register.......................................................... 293
NCOxINCH Register......................................................... 295
NCOxINCL Register ......................................................... 295
Numerically Controlled Oscillator (NCO) .......................... 287
O
OPCODE Field Descriptions............................................. 315
OPTION............................................................................ 325
OPTION Register.............................................................. 165
OSCCON Register.............................................................. 62
Oscillator
Associated Registers.................................................. 63
Associated registers ................................................. 311
Oscillator Module................................................................ 49
ECH ............................................................................ 49
ECL............................................................................. 49
ECM............................................................................ 49
HS............................................................................... 49
INTOSC ...................................................................... 49
PIC16(L)F1508/9
DS41609A-page 378 Preliminary 2011 Microchip Technology Inc.
LP................................................................................ 49
RC............................................................................... 49
XT ............................................................................... 49
Oscillator Parameters........................................................342
Oscillator Specifications.................................................... 342
Oscillator Start-up Timer (OST)
Specifications............................................................ 345
Oscillator Switching
Fail-Safe Clock Monitor............................................... 60
Two-Speed Clock Start-up.......................................... 58
OSCSTAT Register.............................................................63
P
Packaging ......................................................................... 363
Marking ............................................................. 363, 364
PDIP Details..............................................................365
PCL and PCLATH............................................................... 16
PCL Register.......................................................................28
PCLATH Register................................................................28
PCON Register .............................................................29, 71
PIE1 Register................................................................29, 79
PIE2 Register................................................................29, 80
PIE3 Register................................................................29, 81
Pinout Descriptions
PIC16(L)F1508/9 ........................................................ 11
PIR1 Register................................................................ 29, 82
PIR2 Register................................................................ 29, 83
PIR3 Register................................................................ 29, 84
PMADR Registers...............................................................95
PMADRH Registers ............................................................ 95
PMADRL Register.............................................................108
PMADRL Registers.............................................................95
PMCON1 Register ...................................................... 95, 109
PMCON2 Register ...................................................... 95, 110
PMDATH Register.............................................................108
PMDATL Register .............................................................108
PMDRH Register............................................................... 108
PORTA.............................................................................. 113
ANSELA Register .....................................................113
Associated Registers ................................................ 116
LATA Register............................................................. 30
PORTA Register ......................................................... 29
Specifications............................................................ 343
PORTA Register ............................................................... 114
PORTB.............................................................................. 117
ANSELB Register .....................................................117
Associated Registers ................................................ 120
LATB Register............................................................. 30
PORTB Register ......................................................... 29
PORTB Register ............................................................... 118
PORTC
ANSELC Register .....................................................121
Associated Registers ................................................ 123
LATC Register ............................................................30
Pin Descriptions and Diagrams................................. 121
PORTC Register ......................................................... 29
PORTC Register ............................................................... 122
Power-Down Mode (Sleep) ................................................. 87
Associated Registers ..................................................90
Power-on Reset ..................................................................66
Power-up Time-out Sequence ............................................ 68
Power-up Timer (PWRT).....................................................66
Specifications............................................................ 345
PR2 Register.......................................................................29
Program Memory ................................................................17
Map and Stack (PIC16(L)F1508 ................................. 18
Map and Stack (PIC16(L)F1509 ................................. 18
Programming, Device Instructions.................................... 315
Pulse Width Modulation (PWM)........................................ 265
Associated registers w/ PWM................................... 270
PWM Mode
Duty Cycle ........................................................ 266
Effects of Reset ................................................ 267
Example PWM Frequencies and
Resolutions, 20 MHZ................................ 267
Example PWM Frequencies and
Resolutions, 8 MHz .................................. 267
Operation in Sleep Mode.................................. 267
Setup for Operation using PWMx pins ............. 268
System Clock Frequency Changes .................. 267
PWM Period.............................................................. 266
Setup for PWM Operation using PWMx Pins ........... 268
PWMxCON Register......................................................... 269
PWMxDCH Register ......................................................... 270
PWMxDCL Register.......................................................... 270
R
RCREG............................................................................. 244
RCREG Register ................................................................ 30
RCSTA Register ......................................................... 30, 247
Reader Response............................................................. 382
Read-Modify-Write Operations ......................................... 315
Registers
ADCON0 (ADC Control 0) ........................................ 141
ADCON1 (ADC Control 1) ........................................ 142
ADCON2 (ADC Control 2) ........................................ 143
ADRESH (ADC Result High) with ADFM = 0) .......... 144
ADRESH (ADC Result High) with ADFM = 1) .......... 145
ADRESL (ADC Result Low) with ADFM = 0)............ 144
ADRESL (ADC Result Low) with ADFM = 1)............ 145
ANSELA (PORTA Analog Select)............................. 115
ANSELB (PORTB Analog Select)............................. 119
ANSELC (PORTC Analog Select) ............................ 123
APFCON (Alternate Pin Function Control) ............... 112
BAUDCON (Baud Rate Control)............................... 248
BORCON Brown-out Reset Control) .......................... 67
CLCDATA (Data Output) .......................................... 285
CLCxCON (CLCx Control)........................................ 277
CLCxGLS0 (Gate 1 Logic Select)............................. 281
CLCxGLS1 (Gate 2 Logic Select)............................. 282
CLCxGLS2 (Gate 3 Logic Select)............................. 283
CLCxGLS3 (Gate 4 Logic Select)............................. 284
CLCxPOL (Signal Polarity Control)........................... 278
CLCxSEL0 (Multiplexer Data 1 and 2 Select)........... 279
CMOUT (Comparator Output) .................................. 160
CMxCON0 (Cx Control)............................................ 159
CMxCON1 (Cx Control 1)......................................... 160
Configuration Word 1.................................................. 44
Configuration Word 2.................................................. 45
Core Function, Summary............................................ 28
CWGxCON0 (CWG Control 0) ................................. 307
CWGxCON1 (CWG Control 1) ................................. 308
CWGxCON2 (CWG Control 1) ................................. 309
CWGxDBF (CWGx Dead Band Falling Count)......... 310
CWGxDBR (CWGx Dead Band Rising Count)......... 310
DACCON0 ................................................................ 152
DACCON1 ................................................................ 152
Device ID .................................................................... 47
FVRCON................................................................... 132
INTCON (Interrupt Control)......................................... 78
IOCAF (Interrupt-on-Change PORTA Flag).............. 127
2011 Microchip Technology Inc. Preliminary DS41609A-page 379
PIC16(L)F1508/9
IOCAN (Interrupt-on-Change PORTA
Negative Edge) ................................................. 127
IOCAP (Interrupt-on-Change PORTA
Positive Edge)................................................... 127
IOCBF (Interrupt-on-Change PORTB Flag).............. 128
IOCBN (Interrupt-on-Change PORTB
Negative Edge) ................................................. 128
IOCBP (Interrupt-on-Change PORTB
Positive Edge)................................................... 128
LATA (Data Latch PORTA)....................................... 115
LATB (Data Latch PORTB)....................................... 119
LATC (Data Latch PORTC) ......................................122
NCOxACCH (NCOx Accumulator High Byte) ........... 294
NCOxACCL (NCOx Accumulator Low Byte)............. 294
NCOxACCU (NCOx Accumulator Upper Byte)......... 294
NCOxCLK (NCOx Clock Control) ............................. 293
NCOxCON (NCOx Control) ...................................... 293
NCOxINCH (NCOx Increment High Byte)................. 295
NCOxINCL (NCOx Increment Low Byte).................. 295
OPTION_REG (OPTION) ......................................... 165
OSCCON (Oscillator Control) ..................................... 62
OSCSTAT (Oscillator Status) ..................................... 63
PCON (Power Control Register) ................................. 71
PCON (Power Control) ............................................... 71
PIE1 (Peripheral Interrupt Enable 1)........................... 79
PIE2 (Peripheral Interrupt Enable 2)........................... 80
PIE3 (Peripheral Interrupt Enable 3)........................... 81
PIR1 (Peripheral Interrupt Register 1) ........................ 82
PIR2 (Peripheral Interrupt Request 2) ........................ 83
PIR3 (Peripheral Interrupt Request 3) ........................ 84
PMADRL (Program Memory Address)...................... 108
PMCON1 (Program Memory Control 1).................... 109
PMCON2 (Program Memory Control 2).................... 110
PMDATH (Program Memory Data)........................... 108
PMDATL (Program Memory Data)............................ 108
PMDRH (Program Memory Address) ....................... 108
PORTA...................................................................... 114
PORTB...................................................................... 118
PORTC ..................................................................... 122
PWMxCON (PWM Control)....................................... 269
PWMxDCH (PWM Control)....................................... 270
PWMxDCL (PWM Control) ....................................... 270
RCREG ..................................................................... 254
RCSTA (Receive Status and Control)....................... 247
SPBRGH................................................................... 249
SPBRGL ................................................................... 249
Special Function, Summary........................................29
SSPxADD (MSSPx Address and Baud Rate,
I2C Mode) ......................................................... 235
SSPxCON1 (MSSPx Control 1) ................................ 232
SSPxCON2 (SSPx Control 2)................................... 233
SSPxCON3 (SSPx Control 3)................................... 234
SSPxMSK (SSPx Mask) ........................................... 235
SSPxSTAT (SSPx Status) ........................................ 231
STATUS...................................................................... 21
T1CON (Timer1 Control)........................................... 175
T1GCON (Timer1 Gate Control)............................... 176
T2CON...................................................................... 181
TRISA (Tri-State PORTA)......................................... 114
TRISB (Tri-State PORTB)......................................... 118
TRISC (Tri-State PORTC) ........................................ 122
TXSTA (Transmit Status and Control) ...................... 246
VREGCON (Voltage Regulator Control) ..................... 90
WDTCON (Watchdog Timer Control) ......................... 93
WPUA (Weak Pull-up PORTA)................................. 116
WPUB (Weak Pull-up PORTB)................................. 120
RESET.............................................................................. 325
Reset .................................................................................. 65
Reset Instruction................................................................. 68
Resets ................................................................................ 65
Associated Registers.................................................. 72
Revision History................................................................ 373
S
Software Simulator (MPLAB SIM) .................................... 361
SPBRG Register................................................................. 30
SPBRGH Register ............................................................ 249
SPBRGL Register............................................................. 249
Special Function Registers (SFRs)..................................... 29
SPI Mode (MSSPx)
Associated Registers................................................ 193
SPI Clock.................................................................. 189
SSPOV ............................................................................. 220
SSPOV Status Flag .......................................................... 220
SSPxADD Register........................................................... 235
SSPxCON1 Register ........................................................ 232
SSPxCON2 Register ........................................................ 233
SSPxCON3 Register ........................................................ 234
SSPxMSK Register........................................................... 235
SSPxSTAT Register ......................................................... 231
R/W Bit ..................................................................... 198
Stack................................................................................... 36
Accessing ................................................................... 36
Reset .......................................................................... 38
Stack Overflow/Underflow .................................................. 68
STATUS Register ............................................................... 21
SUBWFB .......................................................................... 327
T
T1CON Register ......................................................... 29, 175
T1GCON Register ............................................................ 176
T2CON (Timer2) Register................................................. 181
T2CON Register ................................................................. 29
Temperature Indicator
Associated Registers................................................ 134
Temperature Indicator Module.......................................... 133
Thermal Considerations.................................................... 340
Timer0 .............................................................................. 163
Associated Registers................................................ 165
Operation.................................................................. 163
Specifications ........................................................... 346
Timer1 .............................................................................. 167
Associated registers ................................................. 177
Asynchronous Counter Mode ................................... 169
Reading and Writing......................................... 169
Clock Source Selection ............................................ 168
Interrupt .................................................................... 171
Operation.................................................................. 168
Operation During Sleep ............................................ 171
Prescaler .................................................................. 169
Specifications ........................................................... 346
Timer1 Gate
Selecting Source .............................................. 169
TMR1H Register....................................................... 167
TMR1L Register ....................................................... 167
Timer2 .............................................................................. 179
Associated registers ................................................. 182
Timers
Timer1
T1CON ............................................................. 175
T1GCON........................................................... 176
PIC16(L)F1508/9
DS41609A-page 380 Preliminary 2011 Microchip Technology Inc.
Timer2
T2CON.............................................................. 181
Timing Diagrams
A/D Conversion.........................................................347
A/D Conversion (Sleep Mode) .................................. 348
Acknowledge Sequence ........................................... 222
Asynchronous Reception .......................................... 244
Asynchronous Transmission ..................................... 240
Asynchronous Transmission (Back to Back) ............ 240
Auto Wake-up Bit (WUE) During Normal Operation . 256
Auto Wake-up Bit (WUE) During Sleep .................... 256
Automatic Baud Rate Calibration.............................. 254
Baud Rate Generator with Clock Arbitration ............. 215
BRG Reset Due to SDA Arbitration During Start
Condition........................................................... 226
Brown-out Reset (BOR) ............................................344
Brown-out Reset Situations ........................................ 67
Bus Collision During a Repeated Start Condition
(Case 1) ............................................................227
Bus Collision During a Repeated Start Condition
(Case 2) ............................................................227
Bus Collision During a Start Condition (SCL = 0) ..... 226
Bus Collision During a Stop Condition (Case 1) .......228
Bus Collision During a Stop Condition (Case 2) .......228
Bus Collision During Start Condition (SDA only) ...... 225
Bus Collision for Transmit and Acknowledge............ 224
CLKOUT and I/O....................................................... 343
Clock Synchronization ..............................................212
Clock Timing ............................................................. 342
Comparator Output ...................................................153
Fail-Safe Clock Monitor (FSCM) ................................. 61
First Start Bit Timing .................................................216
I2C Bus Data.............................................................354
I2C Bus Start/Stop Bits.............................................. 354
I2C Master Mode (7 or 10-Bit Transmission) ............ 219
I2C Master Mode (7-Bit Reception)........................... 221
I2C Stop Condition Receive or Transmit Mode ......... 223
INT Pin Interrupt..........................................................76
Internal Oscillator Switch Timing................................. 56
Repeat Start Condition.............................................. 217
Reset Start-up Sequence............................................ 69
Reset, WDT, OST and Power-up Timer ................... 344
Send Break Character Sequence ............................. 257
SPI Master Mode (CKE = 1, SMP = 1) .....................351
SPI Mode (Master Mode).......................................... 189
SPI Slave Mode (CKE = 0) .......................................352
SPI Slave Mode (CKE = 1) .......................................352
Synchronous Reception (Master Mode, SREN) ....... 261
Synchronous Transmission....................................... 259
Synchronous Transmission (Through TXEN) ........... 259
Timer0 and Timer1 External Clock ........................... 345
Timer1 Incrementing Edge........................................ 171
Two Speed Start-up .................................................... 59
USART Synchronous Receive (Master/Slave) ......... 350
USART Synchronous Transmission
(Master/Slave)...................................................350
Wake-up from Interrupt ...............................................88
Timing Parameter Symbology...........................................341
Timing Requirements
I2C Bus Data.............................................................355
I2C Bus Start/Stop Bits .............................................354
SPI Mode ..................................................................353
TMR0 Register....................................................................29
TMR1H Register .................................................................29
TMR1L Register.................................................................. 29
TMR2 Register.................................................................... 29
TRIS.................................................................................. 328
TRISA Register........................................................... 29, 114
TRISB Register........................................................... 29, 118
TRISC ............................................................................... 121
TRISC Register........................................................... 29, 122
Two-Speed Clock Start-up Mode........................................ 58
TXREG ............................................................................. 239
TXREG Register................................................................. 30
TXSTA Register.......................................................... 30, 246
BRGH Bit .................................................................. 249
U
USART
Synchronous Master Mode
Requirements, Synchronous Receive .............. 350
Requirements, Synchronous Transmission...... 350
Timing Diagram, Synchronous Receive ........... 350
Timing Diagram, Synchronous Transmission... 350
V
VREF. SEE ADC Reference Voltage
VREGCON Register ........................................................... 90
W
Wake-up on Break ............................................................ 255
Wake-up Using Interrupts................................................... 87
Watchdog Timer (WDT)...................................................... 68
Associated Registers.................................................. 94
Modes......................................................................... 92
Specifications ........................................................... 345
WCOL ....................................................... 215, 218, 220, 222
WCOL Status Flag.................................... 215, 218, 220, 222
WDTCON Register ............................................................. 93
WPUA Register................................................................. 116
WPUB Register................................................................. 120
Write Protection .................................................................. 46
WWW Address ................................................................. 381
WWW, On-Line Support ....................................................... 8
2011 Microchip Technology Inc. Preliminary DS41609A-page 381
PIC16(L)F1508/9
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:
•Product Support – Data sheets and errata,
application notes and sample programs, design
resources, user’s guides and hardware support
documents, latest software releases and archived
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•General Technical Support – Frequently Asked
Questions (FAQ), technical support requests,
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program member listing
•Business of Microchip – Product selector and
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listing of seminars and events, listings of
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
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“Customer Change Notification” and follow the
registration instructions.
CUSTOMER SUPPORT
Users of Microchip products can receive assistance
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• Distributor or Representative
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Customers should contact their distributor,
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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://microchip.com/support
PIC16(L)F1508/9
DS41609A-page 382 Preliminary 2011 Microchip Technology Inc.
READER RESPONSE
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip
product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our
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DS41609APIC16(L)F1508/9
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?
2011 Microchip Technology Inc. Preliminary DS41609A-page 383
PIC16(L)F1508/9
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: PIC16F1508, PIC16LF1508,
PIC16F1509, PIC16LF1509
Tape and Reel
Option:
Blank = Standard packaging (tube or tray)
T = Tape and Reel(1)
Temperature
Range:
I= -40C to +85C(Industrial)
E= -40
C to +125C (Extended)
Package: ML = Micro Lead Frame (QFN) 4x4
P=Plastic DIP
SO = SOIC
SS = SSOP
Pattern: QTP, SQTP, Code or Special Requirements
(blank otherwise)
Examples:
a) PIC16LF1508T - I/SO
Tape and Reel,
Industrial temperature,
SOIC package
b) PIC16F1509 - I/P
Industrial temperature
PDIP package
c) PIC16F1508 - E/ML
Extended temperature,
QFN package
QTP pattern #298
Note 1: Tape and Reel identifier only appears in the
catalog part number description. This
identifier is used for ordering purposes and is
not printed on the device package. Check
with your Microchip Sales Office for package
availability with the Tape and Reel option.
[X](1)
Tape and Reel
Option
-
DS41609A-page 384 Preliminary 2011 Microchip Technology Inc.
AMERICAS
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Worldwide Sales and Service
08/02/11
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Microchip:
PIC16F1508-I/ML PIC16F1508-I/P PIC16F1508-I/SO PIC16F1508-I/SS PIC16F1509-I/ML PIC16F1509-I/P
PIC16F1509-I/SO PIC16F1509-I/SS PIC16F1508-E/ML PIC16F1508-E/P PIC16F1508-E/SO PIC16F1508-E/SS
PIC16F1508T-I/ML PIC16F1508T-I/SO PIC16F1508T-I/SS PIC16F1509-E/ML PIC16F1509-E/P PIC16F1509-E/SO
PIC16F1509-E/SS PIC16F1509T-I/ML PIC16F1509T-I/SO PIC16F1509T-I/SS PIC16LF1508-E/ML PIC16LF1508-
E/P PIC16LF1508-E/SO PIC16LF1508-E/SS PIC16LF1508-I/ML PIC16LF1508-I/P PIC16LF1508-I/SO
PIC16LF1508T-I/ML PIC16LF1508T-I/SO PIC16LF1508T-I/SS PIC16LF1509-E/ML PIC16LF1509-E/P PIC16LF1509-
E/SO PIC16LF1509-E/SS PIC16LF1509-I/ML PIC16LF1509-I/P PIC16LF1509-I/SO PIC16LF1509-I/SS
PIC16LF1509T-I/ML PIC16LF1509T-I/SO PIC16LF1509T-I/SS