PIC18F1330-I/PREL - Microchip Technology

PIC18F1230/1330

Data Sheet

18/20/28-Pin Enhanced Flash

Microcontrollers with nanoWatt Technology,

High Performance PWM and A/D

Information contained in this publication regarding device

applications and the like is provided only for your convenience

and may be superseded by updates. It is your responsibility to

ensure that your application meets with your specifications.

MICROCHIP MAKES NO REPRESENTATIONS OR

WARRANTIES OF ANY KIND WHETHER EXPRESS OR

IMPLIED, WRITTEN OR ORAL, STATUTORY OR

OTHERWISE, RELATED TO THE INFORMATION,

INCLUDING BUT NOT LIMITED TO ITS CONDITION,

QUALITY, PERFORMANCE, MERCHANTABILITY OR

FITNESS FOR PURPOSE. Microchip disclaims all liability

arising from this information and its use. Use of Microchip

devices in life support and/or safety applications is entirely at

the buyer’s risk, and the buyer agrees to defend, indemnify and

hold harmless Microchip from any and all damages, claims,

suits, or expenses resulting from such use. No licenses are

conveyed, implicitly or otherwise, under any Microchip

intellectual property rights.

Trademarks

The Microchip name and logo, the Microchip logo, Accuron,

dsPIC, KEELOQ, KEELOQ logo, microID, MPLAB, PIC,

PICmicro, PICSTART, PRO MATE, PowerSmart, rfPIC, and

SmartShunt are registered trademarks of Microchip

Technology Incorporated in the U.S.A. and other countries.

AmpLab, FilterLab, Linear Active Thermistor, Migratable

Memory, MXDEV, MXLAB, PS logo, SEEVAL, SmartSensor

and The Embedded Control Solutions Company are

registered trademarks of Microchip Technology Incorporated

in the U.S.A.

Analog-for-the-Digital Age, Application Maestro, CodeGuard,

dsPICDEM, dsPICDEM.net, dsPICworks, ECAN,

ECONOMONITOR, FanSense, FlexROM, fuzzyLAB,

In-Circuit Serial Programming, ICSP, ICEPIC, Mindi, MiWi,

MPASM, MPLAB Certified logo, MPLIB, MPLINK, PICkit,

PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal,

PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB,

rfPICDEM, Select Mode, Smart Serial, SmartTel, Total

Endurance, UNI/O, WiperLock and ZENA are trademarks of

Microchip Technology Incorporated in the U.S.A. and other

countries.

SQTP is a service mark of Microchip Technology Incorporated

in the U.S.A.

All other trademarks mentioned herein are property of their

respective companies.

Printed on recycled paper.

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

products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts

allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Microchip received ISO/TS-16949:2002 certification for its worldwide

headquarters, design and wafer fabrication facilities in Chandler and

Tempe, Arizona, Gresham, Oregon and Mountain View, California. The

Company’s quality system processes and procedures are for its PIC

MCUs and dsPIC

DSCs, KEELOQ

code hopping devices, Serial

EEPROMs, microperipherals, nonvolatile memory and analog

products. In addition, Microchip’s quality system for the design and

manufacture of development systems is ISO 9001:2000 certified.

14-Bit Power Control PWM Module:

• Up to 6 PWM Channel Outputs

- Complementary or independent outputs

• Edge or Center-Aligned Operation

• Flexible Dead-Band Generator

• Hardware Fault Protection Input

• Simultaneous Update of Duty Cycle and Period:

- Flexible Special Event Trigger output

Flexible Oscillator Structure:

• Four Crystal modes, up to 40 MHz

• 4x Phase Lock Loop (PLL) – Available for Crystal

and Internal Oscillators

• Two External RC modes, up to 4 MHz

• Two External Clock modes, up to 40 MHz

• Internal Oscillator Block:

- 8 user-selectable frequencies from 31 kHz

to 8 MHz

- Provides a complete range of clock speeds from

31 kHz to 32 MHz when used with PLL

- User-tunable to compensate for frequency drift

• Secondary Oscillator using Timer1 @ 32 kHz

• Fail-Safe Clock Monitor:

- Allows for safe shutdown if peripheral clock stops

Power-Managed Modes:

• Run: CPU on, peripherals on

• Idle: CPU off, peripherals on

• Sleep: CPU off, peripherals off

• Idle mode currents down to 5.8 μA, typical

• Sleep mode current down to 0.1 μA, typical

• Timer1 Oscillator: 1.8 μA, typical; 32 kHz; 2V

• Watchdog Timer (WDT): 2.1 μA, typical

• Two-Speed Oscillator Start-up

Peripheral Highlights:

• High-Current Sink/Source 25 mA/25 mA

• Up to 4 Programmable External Interrupts

• Four Input Change Interrupts

• Enhanced Addressable USART module:

- Supports RS-485, RS-232 and LIN 1.2

- RS-232 operation using internal oscillator

block (no external crystal required)

- Auto-wake-up on Start bit

- Auto-Baud Detect

• 10-Bit, up to 4-Channel Analog-to-Digital Converter

module (A/D):

- Auto-acquisition capability

- Conversion available during Sleep

• Up to 3 Analog Comparators

• Programmable Reference Voltage for

Comparators

• Programmable, 15-Level Low-Voltage Detection

(LVD) module:

- Supports interrupt on Low-Voltage Detection

Special Microcontroller Features:

• C Compiler Optimized Architecture with Optional

Extended Instruction Set

• Flash Memory Retention: > 40 years

• Self-Programmable under Software Control

• Priority Levels for Interrupts

• 8 x 8 Single-Cycle Hardware Multiplier

• Extended Watchdog Timer (WDT):

- Programmable period from 4 ms to 131s

• Programmable Code Protection

• Single-Supply In-Circuit Serial Programming™

(ICSP™) via Two Pins

• In-Circuit Debug (ICD) via Two Pins

• Wide Operating Voltage Range (2.0V to 5.5V)

Device

Program Memory Data Memory

I/O

10-Bit

ADC

Channel

EUSART Analog

Comparator

14-Bit

PWM (ch)

Timers

16-Bit

Flash

(bytes)

# Single-Word

Instructions

SRAM

(bytes)

EEPROM

(bytes)

PIC18F1230 4096 2048 256 128 16 4 Yes 3 6 2

PIC18F1330 8192 4096 256 128 16 4 Yes 3 6 2

18/20/28 -Pin Enhan ced Flash Microcontrollers with

nanoWatt Technology, High-Performance PWM and A/D

PIC18F1230/1330

Pin Diagrams

18-Pin PDIP, SOIC

RA0/AN0/INT0/KBI0/CMP0

RA1/AN1/INT1/KBI1

RA4/T0CKI/AN2/VREF+

VSS/AVSS

RA2/TX/CK

RA3/RX/DT

RB0/PWM0

RB1/PWM1

PIC18F1X30

RB3/INT3/KBI3/CMP1/T1OSI(1)

RA7/OSC1/CLKI/T1OSI(1)/FLTA(2)

RA6/OSC2/CLKO/T1OSO(1)/T1CKI(1)/AN3

VDD/AVDD

RB7/PWM5/PGD

RB6/PWM4/PGC

RB5/PWM3

RB4/PWM2

20-Pin SSOP

Note 1: Placement of T1OSI and T1OSO/T1CKI depends on the value of Configuration bit, T1OSCMX, of

CONFIG3H.

2: Placement of FLTA depends on the value of Configuration bit, FLTAMX, of CONFIG3H.

MCLR/VPP/RA5/FLTA(2)

RA0/AN0/INT0/KBI0/CMP0

RA1/AN1/INT1/KBI1

RA4/T0CKI/AN2/VREF+

VSS

RA2/TX/CK

RA3/RX/DT

RB0/PWM0

RB1/PWM1

PIC18F1X30

RB3/INT3/KBI3/CMP1/T1OSI(1)

RA7/OSC1/CLKI/T1OSI(1)/FLTA(2)

VDD

RB7/PWM5/PGD

RB6/PWM4/PGC

RB5/PWM3

RB4/PWM2

MCLR/VPP/RA5/FLTA(2)

10 11

AVSS AVDD

RB2/INT2/KBI2/CMP2/T1OSO(1)/T1CKI(1)

RA6/OSC2/CLKO/T1OSO(1)/T1CKI(1)/AN3

RB2/INT2/KBI2/CMP2/T1OSO(1)/T1CKI(1)

PIC18F1230/1330

Pin Diagrams (Continued)

28-Pin QFN(3)

Note 1: Placement of T1OSI and T1OSO/T1CKI depends on the value of Configuration bit, T1OSCMX, of

CONFIG3H.

2: Placement of FLTA depends on the value of Configuration bit, FLTAMX, of CONFIG3H.

3: It is recommended that the user connect the center metal pad for this device package to the ground.

10 11

12 13 14 15

232425262728

PIC18F1X30

RA3/RX/DT

RB3/INT3/KBI3/CMP1/T1OSI(1)

RA7/OSC1/CLKI/T1OSI(1)/FLTA(2)

VDD

AVDD

RB7/PWM5/PGD

RB6/PWM4/PGC

RB5/PWM3

RB4/PWM2

RA0/AN0/INT0/KBI0/CMP0

RA1/AN1/INT1/KBI1

RA4/T0CKI/AN2/VREF+

MCLR/VPP/RA5/FLTA(2)

VSS

AVSS

RA2/TX/CK

RB0/PWM0

RB1/PWM1

RB2/INT2/KBI2/CMP2/T1OSO(1)/T1CKI(1)

RA6/OSC2/CLKO/T1OSO(1)/T1CKI(1)/AN3

PIC18F1230/1330
DS39758C-page 4 Advance Information © 2007 Microchip Technology Inc.
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 7
2.0 Oscillator Configurations ............................................................................................................................................................ 15
3.0 Power-Managed Modes ............................................................................................................................................................. 25
4.0 Reset .......................................................................................................................................................................................... 33
5.0 Memory Organization ................................................................................................................................................................. 45
6.0 Flash Program Memory.............................................................................................................................................................. 65
7.0 Data EEPROM Memory ............................................................................................................................................................. 75
8.0 8 x 8 Hardware Multiplier............................................................................................................................................................ 79
9.0 I/O Ports ..................................................................................................................................................................................... 81
10.0 Interrupts .................................................................................................................................................................................... 87
11.0 Timer0 Module ......................................................................................................................................................................... 101
12.0 Timer1 Module ......................................................................................................................................................................... 105
13.0 Power Control PWM Module .................................................................................................................................................... 111
14.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................................... 141
15.0 10-bit Analog-to-Digital Converter (A/D) Module ...................................................................................................................... 163
16.0 Comparator Module.................................................................................................................................................................. 173
17.0 Comparator Voltage Reference Module................................................................................................................................... 177
18.0 Low-Voltage Detect (LVD)........................................................................................................................................................ 179
19.0 Special Features of the CPU.................................................................................................................................................... 183
20.0 Development Support............................................................................................................................................................... 203
21.0 Instruction Set Summary .......................................................................................................................................................... 207
22.0 Electrical Characteristics .......................................................................................................................................................... 257
23.0 DC and AC Characteristics Graphs and Tables....................................................................................................................... 287
24.0 Packaging Information.............................................................................................................................................................. 289
Appendix A: Revision History............................................................................................................................................................. 295
Appendix B: Device Differences......................................................................................................................................................... 295
Appendix C: Conversion Considerations ........................................................................................................................................... 296
Appendix D: Migration from Baseline to Enhanced Devices.............................................................................................................. 296
Appendix E: Migration from Mid-Range TO Enhanced Devices ........................................................................................................ 297
Appendix F: Migration from High-End to Enhanced Devices ............................................................................................................. 297
Index .................................................................................................................................................................................................  299
The Microchip Web Site..................................................................................................................................................................... 307
Customer Change Notification Service .............................................................................................................................................. 307
Customer Support .............................................................................................................................................................................. 307
Reader Response .............................................................................................................................................................................. 308
PIC18F1230/1330 Product Identification System .............................................................................................................................. 309

PIC18F1230/1330

TO OUR VALUED CUSTOMERS

It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip

products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and

enhanced as new volumes and updates are introduced.

If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via

E-mail at docerrors@microchip.com or fax the Reader Response Form in the back of this data sheet to (480) 792-4150. We

welcome your feedback.

Most Current Data Sheet

To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:

http://www.microchip.com

You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page.

The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000).

Errata

An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current

devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision

of silicon and revision of document to which it applies.

To determine if an errata sheet exists for a particular device, please check with one of the following:

• Microchip’s Worldwide Web site; http://www.microchip.com

• Your local Microchip sales office (see last page)

When contacting a sales office, please specify which device, revision of silicon and data sheet (include literature number) you are

using.

Customer Notification System

PIC18F1230/1330

NOTES:

PIC18F1230/1330

1.0 DEVICE OVERVIEW

This document contains device-specific information for

the following devices:

This family offers the advantages of all PIC18 micro-

controllers – namely, high computational performance at

an economical price – with the addition of high-

endurance Enhanced Flash program memory. On top of

these features, the PIC18F1230/1330 family introduces

design enhancements that make these microcontrollers

a logical choice for many high-performance, power

control and motor control applications.

Peripheral highlights include:

• 14-bit resolution Power Control PWM module

(PCPWM) with programmable dead-time insertion

The PCPWM can generate up to six complementary

PWM outputs with dead-band time insertion. Overdrive

current is detected by off-chip analog comparators or

the digital Fault input (FLTA).

PIC18F1230/1330 devices also feature Flash program

memory and an internal RC oscillator.

1.1 New Core Features

1.1.1 nanoWatt TECHNOLOGY

All of the devices in the PIC18F1230/1330 family incor-

porate a range of features that can significantly reduce

power consumption during operation. Key items

include:

•Alternate Run Modes: By clocking the controller

from the Timer1 source or the internal oscillator

block, power consumption during code execution

can be reduced by as much as 90%.

•Multiple Idle Modes: The controller can also run

with its CPU core disabled but the peripherals still

active. In these states, power consumption can be

reduced even further, to as little as 4% of normal

operation requirements.

•On-the-Fly Mode Switching: The power-managed

modes are invoked by user code during operation,

allowing the user to incorporate power-saving ideas

into their application’s software design.

•Low Consumption in Key Modules: The power

requirements for both Timer1 and the Watchdog

Timer are minimized. See Section 22.0 “Electrical

Characteristics” for values.

1.1.2 MULTIPLE OSCILLATOR OPTIONS

AND FEATURES

All of the devices in the PIC18F1230/1330 family offer

ten different oscillator options, allowing users a wide

range of choices in developing application hardware.

These include:

• Four Crystal modes, using crystals or ceramic

resonators.

• Two External Clock modes, offering the option of

using two pins (oscillator input and a divide-by-4

clock output) or one pin (oscillator input, with the

second pin reassigned as general I/O).

• Two External RC Oscillator modes with the same

pin options as the External Clock modes.

• An internal oscillator block which provides an 8 MHz

clock and an INTRC source (approximately 31 kHz),

as well as a range of six user-selectable clock

frequencies, between 125 kHz to 4 MHz, for a total of

eight clock frequencies. This option frees the two

oscillator pins for use as additional general

purpose I/Os.

• A Phase Lock Loop (PLL) frequency multiplier,

available to both the High-Speed Crystal and Internal

Oscillator modes, which allows clock speeds of up to

40 MHz. Used with the internal oscillator, the PLL

gives users a complete selection of clock speeds,

from 31 kHz to 32 MHz, all without using an external

crystal or clock circuit.

Besides its availability as a clock source, the internal

oscillator block provides a stable reference source that

gives the family additional features for robust

operation:

•Fail-Safe Clock Monitor: This option constantly

monitors the main clock source against a reference

signal provided by the internal oscillator. If a clock

failure occurs, the controller is switched to the

internal oscillator block, allowing for continued

low-speed operation or a safe application

shutdown.

•Two-Speed Start-up: This option allows the

internal oscillator to serve as the clock source

from Power-on Reset, or wake-up from Sleep

mode, until the primary clock source is available.

• PIC18F1230 • PIC18F1330

PIC18F1230/1330

1.2 Other Special Features

•Memory Endurance: The Enhanced Flash cells for

both program memory and data EEPROM are rated

to last for many thousands of erase/write cycles –

up to 100,000 for program memory and 1,000,000

for EEPROM. Data retention without refresh is

conservatively estimated to be greater than

40 years.

•Self-Programmability: These devices can write to

their own program memory spaces under internal

software control. By using a bootloader routine

located in the protected Boot Block at the top of

program memory, it becomes possible to create an

application that can update itself in the field.

•Extended Instruction Set: The PIC18F1230/1330

family introduces an optional extension to the PIC18

instruction set, which adds eight new instructions

and an Indexed Addressing mode. This extension,

enabled as a device configuration option, has been

specifically designed to optimize re-entrant

application code originally developed in high-level

languages, such as C.

• Power Control PWM Module: This module

provides up to six modulated outputs for controlling

half-bridge and full-bridge drivers. Other features

include auto-shutdown on Fault detection and

auto-restart to reactivate outputs once the condition

has cleared.

•Enhanced Addressable USART: This serial

communication module is capable of standard

RS-232 operation and provides support for the LIN

bus protocol. Other enhancements include

automatic Baud Rate Detection and a 16-bit Baud

Rate Generator for improved resolution. When the

microcontroller is using the internal oscillator block,

the EUSART provides stable operation for applica-

tions that talk to the outside world without using an

external crystal (or its accompanying power

requirement).

•10-Bit A/D Converter: This module incorporates

programmable acquisition time, allowing for a

channel to be selected and a conversion to be

initiated without waiting for a sampling period and

thus, reducing code overhead.

•Extended Watchdog Timer (WDT): This enhanced

version incorporates a 16-bit prescaler, allowing an

extended time-out range that is stable across

operating voltage and temperature. See

Section 22.0 “Electrical Characteristics” for

time-out periods.

1.3 Details on Individual Family

Members

Devices in the PIC18F1230/1330 family are available

in 18-pin, 20-pin and 28-pin packages.

The devices are differentiated from each other in one

way:

1. Flash program memory (4 Kbytes for

PIC18F1230, 8 Kbytes for PIC18F1330).

All other features for devices in this family are identical.

These are summarized in Table 1-1.

A block diagram of the PIC18F1220/1320 device archi-

tecture is provided in Figure 1-1. The pinouts for this

device family are listed in Table 1-2.

Like all Microchip PIC18 devices, members of the

PIC18F1230/1330 family are available as both stan-

dard and low-voltage devices. Standard devices with

Enhanced Flash memory, designated with an “F” in the

part number (such as PIC18F1330), accommodate an

operating VDD range of 4.2V to 5.5V. Low-voltage

parts, designated by “LF” (such as PIC18LF1330),

function over an extended VDD range of 2.0V to 5.5V.

PIC18F1230/1330

TABLE 1-1: DEVICE FEATURES

Features PIC18F1230 PIC18F1330

Operating Frequency DC – 40 MHz DC – 40 MHz

Program Memory (Bytes) 4096 8192

Program Memory (Instructions) 2048 4096

Data Memory (Bytes) 256 256

Data EEPROM Memory (Bytes) 128 128

Interrupt Sources 17 17

I/O Ports Ports A, B Ports A, B

Timers 2 2

Power Control PWM Module 6 Channels 6 Channels

Serial Communications Enhanced USART Enhanced USART

10-Bit Analog-to-Digital Module 4 Input Channels 4 Input Channels

Resets (and Delays) POR, BOR,

RESET Instruction,

Stack Full,

Stack Underflow (PWRT, OST),

MCLR (optional),

WDT

POR, BOR,

RESET Instruction,

Stack Full,

Stack Underflow (PWRT, OST),

MCLR (optional),

WDT

Programmable Low-Voltage Detect Yes Yes

Programmable Brown-out Reset Yes Yes

Instruction Set 75 Instructions;

83 with Extended Instruction Set

enabled

75 Instructions;

83 with Extended Instruction Set

enabled

Packages 18-Pin PDIP

18-Pin SOIC

20-Pin SSOP

28-Pin QFN

18-Pin PDIP

18-Pin SOIC

20-Pin SSOP

28-Pin QFN

PIC18F1230/1330

FIGURE 1-1: PIC18F1230/1330 (18-PIN) BLOCK DIAGRAM

Instruction

Decode &

Control

PORTA

RA2/TX/CK

Enhanced

Timer0 Timer1 PCPWM

MCLR/VPP/RA5(1)/FLTA(4)

RA4/T0CKI/AN2/VREF+

RA1/AN1/INT1/KBI1

RA0/AN0/INT0/KBI0/CMP0

Data Latch

Data RAM

Address Latch

Address<12>

BSR FSR0

FSR1

FSR2

412 4

PCH PCL

PCLATH

31 Level Stack

Program Counter

PRODLPRODH

8 x 8 Multiply

WREG

BIT OP

ALU<8>

Address Latch

(8 Kbytes)

Data Latch

inc/dec logic

21 8

Data Bus<8>

Instruction

ROM Latch

Bank0, F

PCLATU

PCU RA3/RX/DT

USART

Table Latch

Tab l e P oi n ter < 2>

inc/dec

logic

RB0/PWM0

Decode

Power-up

Timer

Power-on

Reset

Watchdog

Timer

VDD, VSS

Brown-out

Reset

Precision

Reference

Voltage

Low-Voltage

Programming

In-Circuit

Debugger

Oscillator

Start-up Timer

Timing

Generation

OSC1

(2)

OSC2

(2)

T1OSI

T1OSO

INTRC

Oscillator

Fail-Safe

Clock Monitor

Note 1: RA5 is available only when the MCLR Reset is disabled.

2: OSC1, OSC2, CLKI and CLKO are only available in select oscillator modes and when these pins are not being

used as digital I/O. Refer to Section 2.0 “Oscillator Configurations” for additional information.

3: Placement of T1OSI and T1OSO/T1CKI depends on the value of the Configuration bit, T1OSCMX, of CONFIG3H.

4: Placement of FLTA depends on the value of the Configuration bit, FLTAMX, of CONFIG3H.

Program Memory

(4 Kbytes)

PIC18F1230

PIC18F1330

10-Bit

Data EEPROM

MCLR

(1)

BOR

LVD

A/D Converter

RB1/PWM1

RB7/PWM5/PGD

RA6/OSC2(2)/CLKO(2)/

RA7/OSC1(2)/CLKI(2)/

RB2/INT2/KBI2/CMP2/

RB3/INT3/KBI3/CMP1/

RB6/PWM4/PGC

RB5/PWM3

RB4/PWM2

PORTB

T1OSI(3)

T1OSO(3)/T1CKI(3)

T1OSI(3)/FLTA(4)

T1OSO(3)/T1CKI(3)/AN3

PIC18F1230/1330

TABLE 1-2: PIC18F1230/1330 PINOUT I/O DESCRIPTIONS

Pin Name

Pin Number Pin

Type

Buffer

Type Description

PDIP,

SOIC SSOP QFN

MCLR/VPP/RA5/FLTA

MCLR

VPP

RA5

FLTA(1)

441

Analog

Master Clear (input), programming voltage (input)

or Fault detect input.

Master Clear (Reset) input. This pin is an

active-low Reset to the device.

Programming voltage input.

Digital input.

Fault detect input for PWM.

RA7/OSC1/CLKI/

T1OSI/FLTA

RA7

OSC1

CLKI

T1OSI(2)

FLTA(1)

16 18 21

I/O

Analog

Oscillator crystal, external clock input, Timer1

oscillator input or Fault detect input.

Digital I/O.

Oscillator crystal input or external clock source

input.

External clock source input.

Timer1 oscillator input.

Fault detect input for PWM.

RA6/OSC2/CLKO/

T1OSO/T1CKI/AN3

RA6

OSC2

CLKO

T1OSO(2)

TICKI(2)

AN3

15 17 20

I/O

Analog

Oscillator crystal, clock output, Timer1 oscillator

output or analog input.

Digital I/O.

Oscillator crystal output or external clock

source input.

External clock source output.

Timer1 oscillator output.

Timer1 clock input.

Analog input 3.

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

Note 1: Placement of FLTA depends on the value of Configuration bit, FLTAMX, of CONFIG3H.

2: Placement of T1OSI and T1OSO/T1CKI depends on the value of Configuration bit, T1OSCMX, of

CONFIG3H.

PIC18F1230/1330

PORTA is a bidirectional I/O port.

RA0/AN0/INT0/KBI0/

CMP0

RA0

AN0

INT0

KBI0

CMP0

1126

I/O

TTL

Analog

TTL

Analog

Digital I/O.

Analog input 0.

External interrupt 0.

Interrupt-on-change pin.

Comparator 0 input.

RA1/AN1/INT1/KBI1

RA1

AN1

INT1

KBI1

2227

I/O

TTL

Analog

TTL

Digital I/O.

Analog input 1.

External interrupt 1.

Interrupt-on-change pin.

RA2/TX/CK

RA2

677

I/O

TTL

—

Digital I/O.

EUSART asynchronous transmit.

EUSART synchronous clock.

RA3/RX/DT

RA3

788

I/O

TTL

Digital I/O.

EUSART asynchronous receive.

EUSART synchronous data.

RA4/T0CKI/AN2/VREF+

RA4

T0CKI

AN2

VREF+

3328

I/O

TTL

Analog

Digital I/O.

Timer0 external clock input.

Analog input 2.

A/D reference voltage (high) input.

TABLE 1-2: PIC18F1230/1330 PINOUT I/O DESCRIPTIONS (CONTINUED)

Pin Name

Pin Number Pin

Type

Buffer

Type Description

PDIP,

SOIC SSOP QFN

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

Note 1: Placement of FLTA depends on the value of Configuration bit, FLTAMX, of CONFIG3H.

2: Placement of T1OSI and T1OSO/T1CKI depends on the value of Configuration bit, T1OSCMX, of

CONFIG3H.

PIC18F1230/1330

PORTB is a bidirectional I/O port.

RB0/PWM0

RB0

PWM0

899

I/O

TTL

—

Digital I/O.

PWM module output PWM0.

RB1/PWM1

RB1

PWM1

91010

I/O

TTL

—

Digital I/O.

PWM module output PWM1.

RB2/INT2/KBI2/CMP2/

T1OSO/T1CKI

RB2

INT2

KBI2

CMP2

T1OSO(2)

T1CKI(2)

17 19 23

I/O

TTL

Analog

Digital I/O.

External interrupt 2.

Interrupt-on-change pin.

Comparator 2 input.

Timer1 oscillator output.

Timer1 clock input.

RB3/INT3/KBI3/CMP1/

T1OSI

RB3

INT3

KBI3

CMP1

T1OSI(2)

18 20 24

I/O

TTL

Analog

Digital I/O.

External interrupt 3.

Interrupt-on-change pin.

Comparator 1 input.

Timer1 oscillator input.

RB4/PWM2

RB4

PWM2

10 11 12

I/O

TTL

—

Digital I/O.

PWM module output PWM2.

RB5/PWM3

RB5

PWM3

11 12 13

I/O

TTL

—

Digital I/O.

PWM module output PWM3.

RB6/PWM4/PGC

RB6

PWM4

PGC

12 13 15

I/O

TTL

—

Digital I/O.

PWM module output PWM4.

In-Circuit Debugger and ICSP™ programming

clock pin.

RB7/PWM5/PGD

RB7

PWM5

PGD

13 14 16

I/O

TTL

—

Digital I/O.

PWM module output PWM5.

In-Circuit Debugger and ICSP programming

data pin.

TABLE 1-2: PIC18F1230/1330 PINOUT I/O DESCRIPTIONS (CONTINUED)

Pin Name

Pin Number Pin

Type

Buffer

Type Description

PDIP,

SOIC SSOP QFN

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

Note 1: Placement of FLTA depends on the value of Configuration bit, FLTAMX, of CONFIG3H.

2: Placement of T1OSI and T1OSO/T1CKI depends on the value of Configuration bit, T1OSCMX, of

CONFIG3H.

PIC18F1230/1330

VSS 5 5 3 P — Ground reference for logic and I/O pins.

VDD 14 16 19 P — Positive supply for logic and I/O pins.

AVSS 5 6 5 P — Ground reference for A/D Converter module.

AVDD 14 15 17 P — Positive supply for A/D Converter module.

NC — — 2, 4, 6,

11, 14,

18, 22,

— — No Connect.

TABLE 1-2: PIC18F1230/1330 PINOUT I/O DESCRIPTIONS (CONTINUED)

Pin Name

Pin Number Pin

Type

Buffer

Type Description

PDIP,

SOIC SSOP QFN

Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels I = Input

O = Output P = Power

Note 1: Placement of FLTA depends on the value of Configuration bit, FLTAMX, of CONFIG3H.

2: Placement of T1OSI and T1OSO/T1CKI depends on the value of Configuration bit, T1OSCMX, of

CONFIG3H.

PIC18F1230/1330

2.0 OSCILLATOR

CONFIGURATIONS

2.1 Oscillator Types

PIC18F1230/1330 devices can be operated in ten

different oscillator modes. The user can program the

Configuration bits, FOSC3:FOSC0, in Configuration

1. LP Low-Power Crystal

2. XT Crystal/Resonator

3. HS High-Speed Crystal/Resonator

4. HSPLL High-Speed Crystal/Resonator

with PLL enabled

5. RC External Resistor/Capacitor with

FOSC/4 output on RA6

6. RCIO External Resistor/Capacitor with I/O

on RA6

7. INTIO1 Internal Oscillator with FOSC/4 output

on RA6 and I/O on RA7

8. INTIO2 Internal Oscillator with I/O on RA6

and RA7

9. EC External Clock with FOSC/4 output

10. ECIO External Clock with I/O on RA6

2.2 Crystal Oscillator/Ceramic

Resonators

In XT, LP, HS or HSPLL Oscillator modes, a crystal or

ceramic resonator is connected to the OSC1 and

OSC2 pins to establish oscillation. Figure 2-1 shows

the pin connections.

The oscillator design requires the use of a parallel cut

crystal.

FIGURE 2-1: CRYSTAL/CERAMIC

RESONATOR OPERATION

(XT, LP, HS OR HSPLL

CONFIGURATION)

TABLE 2-1: CAPACITOR SELECTION FOR

CERAMIC RESONATORS

Note: Use of a series cut crystal may give a fre-

quency out of the crystal manufacturer’s

specifications.

Typical Capacitor Values Used:

Mode Freq OSC1 OSC2

XT 3.58 MHz

4.19 MHz

4 MHz

15 pF

30 pF

50 pF

15 pF

30 pF

50 pF

Capacitor values are for design guidance only.

Different capacitor values may be required to produce

acceptable oscillator operation. The user should test

the performance of the oscillator over the expected

VDD and temperature range for the application.

See the notes following Table 2-2 for additional

information.

Note 1: See Table 2-1 and Table 2-2 for initial values of

C1 and C2.

2: A series resistor (RS) may be required for AT

strip cut crystals.

3: RF varies with the oscillator mode chosen.

C1(1)

C2(1)

XTAL

OSC2

OSC1

RF(3)

Sleep

Logic

PIC18FXXXX

RS(2)

Internal

PIC18F1230/1330

TABLE 2-2: CAPACITOR SELECTION FOR

CRYSTAL OSCILLATOR

An external clock source may also be connected to the

OSC1 pin in the HS mode, as shown in Figure 2-2.

FIGURE 2-2: EXTERNAL CLOCK

INPUT OPERATION

(HS OSCILLATOR

CONFIGURATION)

2.3 External Clock Input

The EC and ECIO Oscillator modes require an external

clock source to be connected to the OSC1 pin. There is

no oscillator start-up time required after a Power-on

Reset or after an exit from Sleep mode.

In the EC Oscillator mode, the oscillator frequency

divided by 4 is available on the OSC2 pin. This signal

may be used for test purposes or to synchronize other

logic. Figure 2-3 shows the pin connections for the EC

Oscillator mode.

FIGURE 2-3: EXTERNAL CLOCK

INPUT OPERATION

(EC CONFIGURATION)

The ECIO Oscillator mode functions like the EC mode,

except that the OSC2 pin becomes an additional

general purpose I/O pin. The I/O pin becomes bit 6 of

PORTA (RA6). Figure 2-4 shows the pin connections

for the ECIO Oscillator mode.

FIGURE 2-4: EXTERNAL CLOCK

INPUT OPERATION

(ECIO CONFIGURATION)

Osc Type Crystal

Freq

Typical Capacitor Values

Tested:

C1 C2

LP 32 kHz 30 pF 30 pF

XT 1 MHz

4 MHz

15 pF

HS 4 MHz

10 MHz

20 MHz

25 MHz

15 pF

Capacitor values are for design guidance only.

Different capacitor values may be required to produce

acceptable oscillator operation. The user should test

the performance of the oscillator over the expected

VDD and temperature range for the application.

See the notes following this table for additional

information.

Note 1: Higher capacitance increases the stability

of the oscillator but also increases the

start-up time.

2: When operating below 3V VDD, or when

using certain ceramic resonators at any

voltage, it may be necessary to use the

HS mode or switch to a crystal oscillator.

3: Since each resonator/crystal has its own

characteristics, the user should consult

the resonator/crystal manufacturer for

appropriate values of external

components.

4: Rs may be required to avoid overdriving

crystals with low drive level specification.

5: Always verify oscillator performance over

the VDD and temperature range that is

expected for the application.

OSC1

OSC2

Open

Clock from

Ext. System PIC18FXXXX

(HS Mode)

OSC1/CLKI

OSC2/CLKO

FOSC/4

Clock from

Ext. System PIC18FXXXX

OSC1/CLKI

I/O (OSC2)

RA6

Clock from

Ext. System PIC18FXXXX

PIC18F1230/1330

2.4 RC Oscillator

For timing insensitive applications, the “RC” and

“RCIO” device options offer additional cost savings.

The actual oscillator frequency is a function of several

factors:

• supply voltage

• values of the external resistor (REXT) and

capacitor (CEXT)

• operating temperature

Given the same device, operating voltage and

temperature and component values, there will also be

unit-to-unit frequency variations. These are due to

factors such as:

• normal manufacturing variation

• difference in lead frame capacitance between

package types (especially for low CEXT values)

• variations within the tolerance of limits of REXT

and CEXT

In the RC Oscillator mode, the oscillator frequency

divided by 4 is available on the OSC2 pin. This signal

may be used for test purposes or to synchronize other

logic. Figure 2-5 shows how the R/C combination is

connected.

FIGURE 2-5: RC OSCILLATOR MODE

The RCIO Oscillator mode (Figure 2-6) functions like

the RC mode, except that the OSC2 pin becomes an

additional general purpose I/O pin. The I/O pin

becomes bit 6 of PORTA (RA6).

FIGURE 2-6: RCIO OSCILLATOR MODE

2.5 PLL Frequency Multiplier

A Phase Locked Loop (PLL) circuit is provided as an

option for users who wish to use a lower frequency

oscillator circuit or to clock the device up to its highest

rated frequency from a crystal oscillator. This may be

useful for customers who are concerned with EMI due

to high-frequency crystals or users who require higher

clock speeds from an internal oscillator.

2.5.1 HSPLL OSCILLATOR MODE

The HSPLL mode makes use of the HS mode oscillator

for frequencies up to 10 MHz. A PLL then multiplies the

oscillator output frequency by 4 to produce an internal

clock frequency up to 40 MHz. The PLLEN bit is not

available in this oscillator mode.

The PLL is only available to the crystal oscillator when

the FOSC3:FOSC0 Configuration bits are programmed

for HSPLL mode (= 0110).

FIGURE 2-7: PLL BLOCK DIAGRAM

(HS MODE)

2.5.2 PLL AND INTOSC

The PLL is also available to the internal oscillator block

in selected oscillator modes. In this configuration, the

PLL is enabled in software and generates a clock

output of up to 32 MHz. The operation of INTOSC with

the PLL is described in Section 2.6.4 “PLL in INTOSC

Modes”.

OSC2/CLKO

CEXT

REXT

PIC18FXXXX

OSC1

FOSC/4

Internal

Clock

VDD

VSS

Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ

CEXT > 20 pF

CEXT

REXT

PIC18FXXXX

OSC1 Internal

Clock

VDD

VSS

Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ

CEXT > 20 pF

I/O (OSC2)

RA6

MUX

VCO

Loop

Filter

Crystal

Osc

OSC2

OSC1

PLL Enable

FIN

FOUT

SYSCLK

Phase

Comparator

HS Oscillator Enable

÷4

(from Configuration Register 1H)

HS Mode

PIC18F1230/1330
DS39758C-page 18 Advance Information © 2007 Microchip Technology Inc.
2.6 Internal Oscillator Block
The PIC18F1230/1330 devices include an internal
oscillator block which generates two different clock
signals; either can be used as the microcontroller’s clock
source. This may eliminate the need for external
oscillator circuits on the OSC1 and/or OSC2 pins.
The main output (INTOSC) is an 8 MHz clock source,
which can be used to directly drive the device clock. It
also drives a postscaler, which can provide a range of
clock frequencies from 31 kHz to 4 MHz. The INTOSC
output is enabled when a clock frequency from 125 kHz
to 8 MHz is selected.
The other clock source is the internal RC oscillator
(INTRC), which provides a nominal 31 kHz output.
INTRC is enabled if it is selected as the device clock
source; it is also enabled automatically when any of the
following are enabled: 
• Power-up Timer
• Fail-Safe Clock Monitor
• Watchdog Timer
• Two-Speed Start-up
These features are discussed in greater detail in
Section 19.0 “Special Features of the CPU”.
The clock source frequency (INTOSC direct, INTRC
direct or INTOSC postscaler) is selected by configuring
the IRCF bits of the OSCCON register (page 22).
2.6.1 INTIO MODES
Using the internal oscillator as the clock source
eliminates the need for up to two external oscillator
pins, which can then be used for digital I/O. Two distinct
configurations are available:
• In INTIO1 mode, the OSC2 pin outputs FOSC/4, 
while OSC1 functions as RA7 for digital input and 
output.
• In INTIO2 mode, OSC1 functions as RA7 and 
OSC2 functions as RA6, both for digital input and 
output.
2.6.2 INTOSC OUTPUT FREQUENCY
The internal oscillator block is calibrated at the factory
to produce an INTOSC output frequency of 8.0 MHz. 
The INTRC oscillator operates independently of the
INTOSC source. Any changes in INTOSC across
voltage and temperature are not necessarily reflected
by changes in INTRC and vice versa.
2.6.3 OSCTUNE REGISTER
The internal oscillator’s output has been calibrated at
the factory but can be adjusted in the user’s
application. This is done by writing to the OSCTUNE
register (Register 2-1). The tuning sensitivity is
constant throughout the tuning range.
When the OSCTUNE register is modified, the INTOSC
frequency will begin shifting to the new frequency. The
INTRC clock will reach the new frequency within
8 clock cycles (approximately 8 * 32 μs=256μs). The
INTOSC clock will stabilize within 1 ms. Code
execution continues during this shift. There is no
indication that the shift has occurred.
The OSCTUNE register also implements the INTSRC
and PLLEN bits, which control certain features of the
internal oscillator block. The INTSRC bit allows users
to select which internal oscillator provides the clock
source when the 31 kHz frequency option is selected.
This is covered in greater detail in Section 2.7.1
“Oscillator Control Register”. 
The PLLEN bit controls the operation of the frequency
multiplier, PLL, in internal oscillator modes.
2.6.4 PLL IN INTOSC MODES
The 4x frequency multiplier can be used with the
internal oscillator block to produce faster device clock
speeds than are normally possible with an internal
oscillator. When enabled, the PLL produces a clock
speed of up to 32 MHz.
Unlike HSPLL mode, the PLL is controlled through
software. The control bit, PLLEN (OSCTUNE<6>), is
used to enable or disable its operation. 
The PLL is available when the device is configured to
use the internal oscillator block as its primary clock
source (FOSC3:FOSC0 = 1001 or 1000). Additionally,
the PLL will only function when the selected output fre-
quency is either 4 MHz or 8 MHz (OSCCON<6:4> = 111
or 110). If both of these conditions are not met, the PLL
is disabled.
The PLLEN control bit is only functional in those inter-
nal oscillator modes where the PLL is available. In all
other modes, it is forced to ‘0’ and is effectively
unavailable.
2.6.5 INTOSC FREQUENCY DRIFT
The factory calibrates the internal oscillator block
output (INTOSC) for 8 MHz. However, this frequency
may drift as VDD or temperature changes, which can
affect the controller operation in a variety of ways. It is
possible to adjust the INTOSC frequency by modifying
the value in the OSCTUNE register. This has no effect
on the INTRC clock source frequency.
Tuning the INTOSC source requires knowing when to
make the adjustment, in which direction it should be
made and in some cases, how large a change is
needed. Two compensation techniques are discussed
in  Section 2.6.5.1 “Compensating with the
EUSART” and Section 2.6.5.2 “Compensating with
the Timers”, but other techniques may be used.

PIC18F1230/1330

2.6.5.1 Compensating with the EUSART

An adjustment may be required when the EUSART

begins to generate framing errors or receives data with

errors while in Asynchronous mode. Framing errors

indicate that the device clock frequency is too high; to

adjust for this, decrement the value in OSCTUNE to

reduce the clock frequency. On the other hand, errors

in data may suggest that the clock speed is too low; to

compensate, increment OSCTUNE to increase the

clock frequency.

2.6.5.2 Compensating with the Timers

This technique compares device clock speed to some

reference clock. Two timers may be used; one timer is

clocked by the peripheral clock, while the other is

clocked by a fixed reference source, such as the

Timer1 oscillator.

Both timers are cleared, but the timer clocked by the

reference generates interrupts. When an interrupt

occurs, the internally clocked timer is read and both

timers are cleared. If the internally clocked timer value

is greater than expected, then the internal oscillator

block is running too fast. To adjust for this, decrement

the OSCTUNE register.

R/W-0 R/W-0(1) U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

INTSRC PLLEN(1) — TUN4 TUN3 TUN2 TUN1 TUN0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 INTSRC: Internal Oscillator Low-Frequency Source Select bit

1 = 31.25 kHz device clock derived from 8 MHz INTOSC source (divide-by-256 enabled)

0 = 31 kHz device clock derived directly from INTRC internal oscillator

bit 6 PLLEN: Frequency Multiplier PLL for INTOSC Enable bit(1)

1 = PLL enabled for INTOSC (4 MHz and 8 MHz only)

0 = PLL disabled

bit 5 Unimplemented: Read as ‘0’

bit 4-0 TUN4:TUN0: Frequency Tuning bits

01111 = Maximum frequency

• •

00001

00000 = Center frequency. Oscillator module is running at the calibrated frequency.

11111

• •

10000 = Minimum frequency

Note 1: Available only in certain oscillator configurations; otherwise, this bit is unavailable and reads as ‘0’. See

Section 2.6.4 “PLL in INTOSC Modes” for details.

PIC18F1230/1330

2.7 Clock Sources and Oscillator

Switching

Like previous PIC18 devices, the PIC18F1230/1330

family includes a feature that allows the device clock

source to be switched from the main oscillator to an

alternate low-frequency clock source. PIC18F1230/1330

devices offer two alternate clock sources. When an alter-

nate clock source is enabled, the various power-managed

operating modes are available.

Essentially, there are three clock sources for these

devices:

• Primary oscillators

• Secondary oscillators

• Internal oscillator block

The primary oscillators include the External Crystal

and Resonator modes, the External RC modes, the

External Clock modes and the internal oscillator block.

The particular mode is defined by the FOSC3:FOSC0

Configuration bits. The details of these modes are

covered earlier in this chapter.

The secondary oscillators are those external sources

not connected to the OSC1 or OSC2 pins. These

sources may continue to operate even after the

controller is placed in a power-managed mode.

PIC18F1230/1330 devices offer the Timer1 oscillator

as a secondary oscillator. This oscillator, in all power-

managed modes, is often the time base for functions

such as a real-time clock.

Most often, a 32.768 kHz watch crystal is connected

between the T1OSO/T1CKI and T1OSI pins. Like the

LP mode oscillator circuit, loading capacitors are also

connected from each pin to ground. The Timer1 oscil-

lator is discussed in greater detail in Section 12.2

“Timer1 Oscillator”.

In addition to being a primary clock source, the internal

oscillator block is available as a power-managed

mode clock source. The INTRC source is also used as

the clock source for several special features, such as

the WDT and Fail-Safe Clock Monitor.

The clock sources for the PIC18F1230/1330 devices

are shown in Figure 2-8. See Section 19.0 “Special

Features of the CPU” for Configuration register details.

FIGURE 2-8: PIC18F1230/1330 CLOCK DIAGRAM

PIC18F1230/1330

4 x PLL

FOSC3:FOSC0

T1OSCEN

Enable

Oscillator

T1OSO

T1OSI

Clock Source Option

for Other Modules

OSC1

OSC2

Sleep HSPLL, INTOSC/PLL

LP, XT, HS, RC, EC

T1OSC

CPU

Peripherals

IDLEN

Postscaler

MUX

8 MHz

4 MHz

2 MHz

1 MHz

500 kHz

125 kHz

250 kHz

OSCCON<6:4>

111

110

101

100

011

010

001

000

31 kHz

INTRC

Source

Internal

Oscillator

Block

WDT, PWRT, FSCM

8 MHz

Internal Oscillator

(INTOSC)

OSCCON<6:4>

Clock

Control

OSCCON<1:0>

Source

8 MHz

31 kHz (INTRC)

OSCTUNE<6>

OSCTUNE<7>

and Two-Speed Start-up

Primary Oscillator

Secondary Oscillator

PIC18F1230/1330

2.7.1 OSCILLATOR CONTROL REGISTER

The OSCCON register (Register 2-2) controls several

aspects of the device clock’s operation, both in full

power operation and in power-managed modes.

The System Clock Select bits, SCS1:SCS0, select the

clock source. The available clock sources are the

primary clock (defined by the FOSC3:FOSC0

Configuration bits), the secondary clock (Timer1

oscillator) and the internal oscillator block. The clock

source changes immediately after one or more of the

bits is written to, following a brief clock transition

interval. The SCS bits are cleared on all forms of Reset.

The Internal Oscillator Frequency Select bits

(IRCF2:IRCF0) select the frequency output of the

internal oscillator block to drive the device clock. The

choices are the INTRC source, the INTOSC source

(8 MHz) or one of the frequencies derived from the

INTOSC postscaler (31.25 kHz to 4 MHz). If the

internal oscillator block is supplying the device clock,

changing the states of these bits will have an immedi-

ate change on the internal oscillator’s output. On

device Resets, the default output frequency of the

internal oscillator block is set at 1 MHz.

When a nominal output frequency of 31 kHz is selected

(IRCF2:IRCF0 = 000), users may choose which

internal oscillator acts as the source. This is done with

the INTSRC bit in the OSCTUNE register

(OSCTUNE<7>). Setting this bit selects INTOSC as a

31.25 kHz clock source by enabling the divide-by-256

output of the INTOSC postscaler. Clearing INTSRC

selects INTRC (nominally 31 kHz) as the clock source.

This option allows users to select the tunable and more

precise INTOSC as a clock source, while maintaining

power savings with a very low clock speed. Regardless

of the setting of INTSRC, INTRC always remains the

clock source for features such as the Watchdog Timer

and the Fail-Safe Clock Monitor.

The OSTS, IOFS and T1RUN bits indicate which clock

source is currently providing the device clock. The

OSTS bit indicates that the Oscillator Start-up Timer

has timed out and the primary clock is providing the

device clock in primary clock modes. The IOFS bit

indicates when the internal oscillator block has

stabilized and is providing the device clock in RC Clock

modes. The T1RUN bit (T1CON<6>) indicates when

the Timer1 oscillator is providing the device clock in

secondary clock modes. In power-managed modes,

only one of these three bits will be set at any time. If

none of these bits are set, the INTRC is providing the

clock or the internal oscillator block has just started and

is not yet stable.

The IDLEN bit determines if the device goes into Sleep

mode or one of the Idle modes when the SLEEP

instruction is executed.

The use of the flag and control bits in the OSCCON

“Power-Managed Modes”.

2.7.2 OSCILLATOR TRANSITIONS

PIC18F1230/1330 devices contain circuitry to prevent

clock “glitches” when switching between clock sources.

A short pause in the device clock occurs during the

clock switch. The length of this pause is the sum of two

cycles of the old clock source and three to four cycles

of the new clock source. This formula assumes that the

new clock source is stable.

Clock transitions are discussed in greater detail in

Section 3.1.2 “Entering Power-Managed Modes”.

Note 1: The Timer1 oscillator must be enabled to

select the secondary clock source. The

Timer1 oscillator is enabled by setting the

T1OSCEN bit in the Timer1 Control regis-

ter (T1CON<3>). If the Timer1 oscillator

is not enabled, then any attempt to select

a secondary clock source will be ignored.

2: It is recommended that the Timer1

oscillator be operating and stable before

selecting the secondary clock source or a

very long delay may occur while the

Timer1 oscillator starts.

PIC18F1230/1330

R/W-0 R/W-1 R/W-0 R/W-0 R(1) R-0 R/W-0 R/W-0

IDLEN IRCF2 IRCF1 IRCF0 OSTS IOFS SCS1 SCS0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 IDLEN: Idle Enable bit

1 = Device enters Idle mode on SLEEP instruction

0 = Device enters Sleep mode on SLEEP instruction

bit 6-4 IRCF2:IRCF0: Internal Oscillator Frequency Select bits

111 = 8 MHz (INTOSC drives clock directly)

110 = 4 MHz

101 = 2 MHz

100 = 1 MHz(3)

011 = 500 kHz

010 = 250 kHz

001 = 125 kHz

000 = 31 kHz (from either INTOSC/256 or INTRC directly)(2)

bit 3 OSTS: Oscillator Start-up Time-out Status bit(1)

1 = Oscillator Start-up Timer time-out has expired; primary oscillator is running

0 = Oscillator Start-up Timer time-out is running; primary oscillator is not ready

bit 2 IOFS: INTOSC Frequency Stable bit

1 = INTOSC frequency is stable

0 = INTOSC frequency is not stable

bit 1-0 SCS1:SCS0: System Clock Select bits

1x = Internal oscillator block

01 = Secondary (Timer1) oscillator

00 = Primary oscillator

Note 1: Reset state depends on state of the IESO Configuration bit.

2: Source selected by the INTSRC bit (OSCTUNE<7>), see text.

3: Default output frequency of INTOSC on Reset.

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 23
2.8 Effects of Power-Managed Modes 
on the Various Clock Sources
When PRI_IDLE mode is selected, the designated
primary oscillator continues to run without interruption.
For all other power-managed modes, the oscillator
using the OSC1 pin is disabled. The OSC1 pin (and
OSC2 pin, if used by the oscillator) will stop oscillating.
In secondary clock modes (SEC_RUN and
SEC_IDLE), the Timer1 oscillator is operating and
providing the device clock. The Timer1 oscillator may
also run in all power-managed modes if required to
clock Timer1 or Timer3.
In internal oscillator modes (RC_RUN and RC_IDLE),
the internal oscillator block provides the device clock
source. The 31 kHz INTRC output can be used directly
to provide the clock and may be enabled to support
various special features, regardless of the power-
managed mode (see Section 19.2 “Watchdog Timer
(WDT)”,  Section 19.3 “Two-Speed Start-up” and
Section 19.4 “Fail-Safe Clock Monitor” for more
information on WDT, Fail-Safe Clock Monitor and Two-
Speed Start-up). The INTOSC output at 8 MHz may be
used directly to clock the device or may be divided
down by the postscaler. The INTOSC output is disabled
if the clock is provided directly from the INTRC output.
If the Sleep mode is selected, all clock sources are
stopped. Since all the transistor switching currents
have been stopped, Sleep mode achieves the lowest
current consumption of the device (only leakage
currents).
Enabling any on-chip feature that will operate during
Sleep will increase the current consumed during Sleep.
The INTRC is required to support WDT operation. The
Timer1 oscillator may be operating to support a real-
time clock. Other features may be operating that do not
require a device clock source (i.e., INTx pins and
others). Peripherals that may add significant current
consumption are listed in Section 22.0 “Electrical
Characteristics”.
2.9 Power-up Delays
Power-up delays are controlled by two timers, so that no
external Reset circuitry is required for most applications.
The delays ensure that the device is kept in Reset until
the device power supply is stable under normal
circumstances and the primary clock is operating and
stable. For additional information on power-up delays,
see Section 4.5 “Device Reset Timers”.
The first timer is the Power-up Timer (PWRT), which
provides a fixed delay on power-up (parameter 33,
Table 22-10). It is enabled by clearing (= 0) the
PWRTEN Configuration bit. 
The second timer is the Oscillator Start-up Timer
(OST), intended to keep the chip in Reset until the
crystal oscillator is stable (LP, XT and HS modes). The
OST does this by counting 1024 oscillator cycles
before allowing the oscillator to clock the device.
When the HSPLL Oscillator mode is selected, the
device is kept in Reset for an additional 2 ms, following
the HS mode OST delay, so the PLL can lock to the
incoming clock frequency.
There is a delay of interval T
CSD (parameter 38,
Table 22-10), following POR, while the controller
becomes ready to execute instructions. This delay runs
concurrently with any other delays. This may be the
only delay that occurs when any of the EC, RC or INTIO
modes are used as the primary clock source.
TABLE 2-3: OSC1 AND OSC2 PIN STATES IN SLEEP MODE  
Oscillator Mode OSC1 Pin OSC2 Pin
RC, INTIO1 Floating, external resistor should pull high At logic low (clock/4 output)
RCIO Floating, external resistor should pull high Configured as PORTA, bit 6
INTIO2 Configured as PORTA, bit 7 Configured as PORTA, bit 6
ECIO Floating, pulled by external clock Configured as PORTA, bit 6
EC Floating, pulled by external clock At logic low (clock/4 output)
LP, XT and HS Feedback inverter disabled at quiescent 
voltage level
Feedback inverter disabled at quiescent 
voltage level
Note: See Table 4-2 in Section 4.0 “Reset” for time-outs due to Sleep and MCLR Reset.

PIC18F1230/1330

NOTES:

PIC18F1230/1330

3.0 POWER-MANAGED MODES

PIC18F1230/1330 devices offer a total of seven

operating modes for more efficient power

management. These modes provide a variety of

options for selective power conservation in applications

where resources may be limited (i.e., battery-powered

devices).

There are three categories of power-managed modes:

• Run modes

• Idle modes

• Sleep mode

These categories define which portions of the device

are clocked and sometimes, what speed. The Run and

Idle modes may use any of the three available clock

sources (primary, secondary or internal oscillator

block); the Sleep mode does not use a clock source.

The power-managed modes include several power-

saving features offered on previous PIC® devices. One

is the clock switching feature, offered in other PIC18

devices, allowing the controller to use the Timer1

oscillator in place of the primary oscillator. Also

included is the Sleep mode, offered by all PIC devices,

where all device clocks are stopped.

3.1 Selecting Power-Managed Modes

Selecting a power-managed mode requires two

decisions: if the CPU is to be clocked or not and the

selection of a clock source. The IDLEN bit

(OSCCON<7>) controls CPU clocking, while the

SCS1:SCS0 bits (OSCCON<1:0>) select the clock

source. The individual modes, bit settings, clock sources

and affected modules are summarized in Table 3-1.

3.1.1 CLOCK SOURCES

The SCS1:SCS0 bits allow the selection of one of three

clock sources for power-managed modes. They are:

• the primary clock, as defined by the

FOSC3:FOSC0 Configuration bits

• the secondary clock (the Timer1 oscillator)

• the internal oscillator block (for RC modes)

3.1.2 ENTERING POWER-MANAGED

MODES

Switching from one power-managed mode to another

begins by loading the OSCCON register. The

SCS1:SCS0 bits select the clock source and determine

which Run or Idle mode is to be used. Changing these

bits causes an immediate switch to the new clock

source, assuming that it is running. The switch may

also be subject to clock transition delays. These are

discussed in Section 3.1.3 “Clock Transitions and

Status Indicators” and subsequent sections.

Entry to the power-managed Idle or Sleep modes is

triggered by the execution of a SLEEP instruction. The

actual mode that results depends on the status of the

IDLEN bit.

Depending on the current mode and the mode being

switched to, a change to a power-managed mode does

not always require setting all of these bits. Many

transitions may be done by changing the oscillator select

bits, or changing the IDLEN bit, prior to issuing a SLEEP

instruction. If the IDLEN bit is already configured

correctly, it may only be necessary to perform a SLEEP

instruction to switch to the desired mode.

TABLE 3-1: POWER-MANAGED MODES

Mode

OSCCON Bits Module Clocking

Available Clock and Oscillator Source

IDLEN<7>(1) SCS1:SCS0

<1:0> CPU Peripherals

Sleep 0N/A Off Off None – All clocks are disabled

PRI_RUN N/A 00 Clocked Clocked Primary – LP, XT, HS, HSPLL, RC, EC and

Internal Oscillator Block(2).

This is the normal full power execution mode.

SEC_RUN N/A 01 Clocked Clocked Secondary – Timer1 Oscillator

RC_RUN N/A 1x Clocked Clocked Internal Oscillator Block(2)

PRI_IDLE 100Off Clocked Primary – LP, XT, HS, HSPLL, RC, EC

SEC_IDLE 101Off Clocked Secondary – Timer1 Oscillator

RC_IDLE 11xOff Clocked Internal Oscillator Block(2)

Note 1: IDLEN reflects its value when the SLEEP instruction is executed.

2: Includes INTOSC and INTOSC postscaler, as well as the INTRC source.

PIC18F1230/1330

3.1.3 CLOCK TRANSITIONS AND STATUS

INDICATORS

The length of the transition between clock sources is

the sum of two cycles of the old clock source and three

to four cycles of the new clock source. This formula

assumes that the new clock source is stable.

Three bits indicate the current clock source and its

status. They are:

• OSTS (OSCCON<3>)

• IOFS (OSCCON<2>)

• T1RUN (T1CON<6>)

In general, only one of these bits will be set while in a

given power-managed mode. When the OSTS bit is

set, the primary clock is providing the device clock.

When the IOFS bit is set, the INTOSC output is

providing a stable 8 MHz clock source to a divider that

actually drives the device clock. When the T1RUN bit is

set, the Timer1 oscillator is providing the clock. If none

of these bits are set, then either the INTRC clock

source is clocking the device, or the INTOSC source is

not yet stable.

If the internal oscillator block is configured as the primary

clock source by the FOSC3:FOSC0 Configuration bits,

then both the OSTS and IOFS bits may be set when in

PRI_RUN or PRI_IDLE modes. This indicates that the

primary clock (INTOSC output) is generating a stable

8 MHz output. Entering another power-managed RC

mode at the same frequency would clear the OSTS bit.

3.1.4 MULTIPLE SLEEP COMMANDS

The power-managed mode that is invoked with the

SLEEP instruction is determined by the setting of the

IDLEN bit at the time the instruction is executed. If

another SLEEP instruction is executed, the device will

enter the power-managed mode specified by IDLEN at

that time. If IDLEN has changed, the device will enter

the new power-managed mode specified by the new

setting.

3.2 Run Modes

In the Run modes, clocks to both the core and

peripherals are active. The difference between these

modes is the clock source.

3.2.1 PRI_RUN MODE

The PRI_RUN mode is the normal, full power execution

mode of the microcontroller. This is also the default

mode upon a device Reset unless Two-Speed Start-up

is enabled (see Section 19.3 “Two-Speed Start-up”

for details). In this mode, the OSTS bit is set. The IOFS

bit may be set if the internal oscillator block is the

primary clock source (see Section 2.7.1 “Oscillator

Control Register”).

3.2.2 SEC_RUN MODE

The SEC_RUN mode is the compatible mode to the

“clock switching” feature offered in other PIC18

devices. In this mode, the CPU and peripherals are

clocked from the Timer1 oscillator. This gives users the

option of lower power consumption while still using a

high accuracy clock source.

SEC_RUN mode is entered by setting the SCS1:SCS0

bits to ‘01’. The device clock source is switched to the

Timer1 oscillator (see Figure 3-1), the primary oscillator

is shut down, the T1RUN bit (T1CON<6>) is set and the

OSTS bit is cleared.

On transitions from SEC_RUN to PRI_RUN mode, the

peripherals and CPU continue to be clocked from the

Timer1 oscillator while the primary clock is started.

When the primary clock becomes ready, a clock switch

back to the primary clock occurs (see Figure 3-2).

When the clock switch is complete, the T1RUN bit is

cleared, the OSTS bit is set and the primary clock is

providing the clock. The IDLEN and SCS bits are not

affected by the wake-up; the Timer1 oscillator

continues to run.

Note 1: Caution should be used when modifying a

single IRCF bit. If VDD is less than 3V, it is

possible to select a higher clock speed

than is supported by the low VDD.

Improper device operation may result if

the VDD/FOSC specifications are violated.

2: Executing a SLEEP instruction does not

necessarily place the device into Sleep

mode. It acts as the trigger to place the

controller into either the Sleep mode or

one of the Idle modes, depending on the

setting of the IDLEN bit.

Note: The Timer1 oscillator should already be

running prior to entering SEC_RUN mode.

If the T1OSCEN bit is not set when the

SCS1:SCS0 bits are set to ‘01’, entry to

SEC_RUN mode will not occur. If the

Timer1 oscillator is enabled, but not yet

running, device clocks will be delayed until

the oscillator has started. In such situa-

tions, initial oscillator operation is far from

stable and unpredictable operation may

result.

PIC18F1230/1330

FIGURE 3-1: TRANSITION TIMING FOR ENTRY TO SEC_RUN MODE

FIGURE 3-2: TRANSITION TIMING FROM SEC_RUN MODE TO PRI_RUN MODE (HSPLL)

3.2.3 RC_RUN MODE

In RC_RUN mode, the CPU and peripherals are

clocked from the internal oscillator block using the

INTOSC multiplexer. In this mode, the primary clock is

shut down. When using the INTRC source, this mode

provides the best power conservation of all the Run

modes, while still executing code. It works well for user

applications which are not highly timing sensitive or do

not require high-speed clocks at all times.

If the primary clock source is the internal oscillator block

(either INTRC or INTOSC), there are no distinguishable

differences between PRI_RUN and RC_RUN modes

during execution. However, a clock switch delay will

occur during entry to and exit from RC_RUN mode.

Therefore, if the primary clock source is the internal

oscillator block, the use of RC_RUN mode is not

recommended.

This mode is entered by setting the SCS1 bit to ‘1’.

Although it is ignored, it is recommended that the SCS0

bit also be cleared; this is to maintain software compat-

ibility with future devices. When the clock source is

switched to the INTOSC multiplexer (see Figure 3-3),

the primary oscillator is shut down and the OSTS bit is

cleared. The IRCF bits may be modified at any time to

immediately change the clock speed.

Q4Q3Q2

OSC1

Peripheral

Program

T1OSI

Counter

Clock

CPU

Clock

PC + 2PC

123 n-1n

Clock Transition(1)

Q4Q3Q2 Q1 Q3Q2

PC + 4

Note 1: Clock transition typically occurs within 2-4 TOSC.

Q1 Q3 Q4

OSC1

Peripheral

Program PC

T1OSI

PLL Clock

PC + 4

Output

Q3 Q4 Q1

CPU Clock

PC + 2

Clock

Counter

Q2 Q2 Q3

Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.

2: Clock transition typically occurs within 2-4 TOSC.

SCS1:SCS0 bits Changed

TPLL(1)

12 n-1n

Clock

OSTS bit Set

Transition(2)

TOST(1)

Note: Caution should be used when modifying a

single IRCF bit. If VDD is less than 3V, it is

possible to select a higher clock speed

than is supported by the low VDD.

Improper device operation may result if

the VDD/FOSC specifications are violated.

PIC18F1230/1330

If the IRCF bits and the INTSRC bit are all clear, the

INTOSC output is not enabled and the IOFS bit will

remain clear; there will be no indication of the current

clock source. The INTRC source is providing the

device clocks.

If the IRCF bits are changed from all clear (thus,

enabling the INTOSC output), or if INTSRC is set, the

IOFS bit becomes set after the INTOSC output

becomes stable. Clocks to the device continue while

the INTOSC source stabilizes after an interval of

TIOBST.

If the IRCF bits were previously at a non-zero value, or

if INTSRC was set before setting SCS1 and the

INTOSC source was already stable, the IOFS bit will

remain set.

On transitions from RC_RUN mode to PRI_RUN mode,

the device continues to be clocked from the INTOSC

multiplexer while the primary clock is started. When the

primary clock becomes ready, a clock switch to the

primary clock occurs (see Figure 3-4). When the clock

switch is complete, the IOFS bit is cleared, the OSTS

bit is set and the primary clock is providing the device

clock. The IDLEN and SCS bits are not affected by the

switch. The INTRC source will continue to run if either

the WDT or the Fail-Safe Clock Monitor is enabled.

FIGURE 3-3: TRANSITION TIMING TO RC_RUN MODE

FIGURE 3-4: TRANSITION TIMING FROM RC_RUN MODE TO PRI_RUN MODE

Q4Q3Q2

OSC1

Peripheral

Program

INTRC

Counter

Clock

CPU

Clock

PC + 2PC

123 n-1n

Clock Transition(1)

Q4Q3Q2 Q1 Q3Q2

PC + 4

Note 1: Clock transition typically occurs within 2-4 TOSC.

Q1 Q3 Q4

OSC1

Peripheral

Program PC

INTOSC

PLL Clock

PC + 4

Output

Q3 Q4 Q1

CPU Clock

PC + 2

Clock

Counter

Q2 Q2 Q3

Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.

2: Clock transition typically occurs within 2-4 TOSC.

SCS1:SCS0 bits Changed

TPLL(1)

12 n-1n

Clock

OSTS bit Set

Transition(2)

Multiplexer

TOST(1)

PIC18F1230/1330

3.3 Sleep Mode

The power-managed Sleep mode in the PIC18F1230/

1330 devices is identical to the legacy Sleep mode

offered in all other PIC devices. It is entered by clearing

the IDLEN bit (the default state on device Reset) and

executing the SLEEP instruction. This shuts down the

selected oscillator (Figure 3-5). All clock source status

bits are cleared.

Entering the Sleep mode from any other mode does not

require a clock switch. This is because no clocks are

needed once the controller has entered Sleep. If the

WDT is selected, the INTRC source will continue to

operate. If the Timer1 oscillator is enabled, it will also

continue to run.

When a wake event occurs in Sleep mode (by interrupt,

Reset or WDT time-out), the device will not be clocked

until the clock source selected by the SCS1:SCS0 bits

becomes ready (see Figure 3-6), or it will be clocked

from the internal oscillator block if either the Two-

Speed Start-up or the Fail-Safe Clock Monitor are

enabled (see Section 19.0 “Special Features of the

CPU”). In either case, the OSTS bit is set when the

primary clock is providing the device clocks. The

IDLEN and SCS bits are not affected by the wake-up.

3.4 Idle Modes

The Idle modes allow the controller’s CPU to be

selectively shut down while the peripherals continue to

operate. Selecting a particular Idle mode allows users

to further manage power consumption.

If the IDLEN bit is set to a ‘1’ when a SLEEP instruction is

executed, the peripherals will be clocked from the clock

source selected using the SCS1:SCS0 bits; however, the

CPU will not be clocked. The clock source status bits are

not affected. Setting IDLEN and executing a SLEEP

instruction provides a quick method of switching from a

given Run mode to its corresponding Idle mode.

If the WDT is selected, the INTRC source will continue

to operate. If the Timer1 oscillator is enabled, it will also

continue to run.

Since the CPU is not executing instructions, the only

exits from any of the Idle modes are by interrupt, WDT

time-out or a Reset. When a wake event occurs, CPU

execution is delayed by an interval of TCSD

(parameter 38, Table 22-10) while it becomes ready to

execute code. When the CPU begins executing code,

it resumes with the same clock source for the current

Idle mode. For example, when waking from RC_IDLE

mode, the internal oscillator block will clock the CPU

and peripherals (in other words, RC_RUN mode). The

IDLEN and SCS bits are not affected by the wake-up.

While in any Idle mode or the Sleep mode, a WDT

time-out will result in a WDT wake-up to the Run mode

currently specified by the SCS1:SCS0 bits.

FIGURE 3-5: TRANSITION TIMING FOR ENTRY TO SLEEP MODE

FIGURE 3-6: TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL)

Q4Q3Q2

OSC1

Peripheral

Sleep

Program

Q1Q1

Counter

Clock

CPU

Clock

PC + 2PC

Q3 Q4 Q1 Q2

OSC1

Peripheral

Program PC

PLL Clock

Q3 Q4

Output

CPU Clock

Q1 Q2 Q3 Q4 Q1 Q2

Clock

Counter PC + 6

PC + 4

Q1 Q2 Q3 Q4

Wake Event

Note1:TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.

TOST(1) TPLL(1)

OSTS bit Set

PC + 2

PIC18F1230/1330

3.4.1 PRI_IDLE MODE

This mode is unique among the three low-power Idle

modes, in that it does not disable the primary device

clock. For timing sensitive applications, this allows for

the fastest resumption of device operation with its more

accurate primary clock source, since the clock source

does not have to “warm-up” or transition from another

oscillator.

PRI_IDLE mode is entered from PRI_RUN mode by

setting the IDLEN bit and executing a SLEEP instruc-

tion. If the device is in another Run mode, set IDLEN

first, then clear the SCS bits and execute SLEEP.

Although the CPU is disabled, the peripherals continue

to be clocked from the primary clock source specified

by the FOSC3:FOSC0 Configuration bits. The OSTS

bit remains set (see Figure 3-7).

When a wake event occurs, the CPU is clocked from the

primary clock source. A delay of interval TCSD is

required between the wake event and when code

execution starts. This is required to allow the CPU to

become ready to execute instructions. After the wake-

up, the OSTS bit remains set. The IDLEN and SCS bits

are not affected by the wake-up (see Figure 3-8).

3.4.2 SEC_IDLE MODE

In SEC_IDLE mode, the CPU is disabled but the

peripherals continue to be clocked from the Timer1

oscillator. This mode is entered from SEC_RUN by

setting the IDLEN bit and executing a SLEEP

instruction. If the device is in another Run mode, set the

IDLEN bit first, then set the SCS1:SCS0 bits to ‘01’ and

execute SLEEP. When the clock source is switched to

the Timer1 oscillator, the primary oscillator is shut

down, the OSTS bit is cleared and the T1RUN bit is set.

When a wake event occurs, the peripherals continue to

be clocked from the Timer1 oscillator. After an interval

of T

CSD following the wake event, the CPU begins

executing code being clocked by the Timer1 oscillator.

The IDLEN and SCS bits are not affected by the

wake-up; the Timer1 oscillator continues to run (see

Figure 3-8).

FIGURE 3-7: TRANSITION TIMING FOR ENTRY TO IDLE MODE

FIGURE 3-8: TRANSITION TIMING FOR WAKE FROM IDLE TO RUN MODE

Note: The Timer1 oscillator should already be

running prior to entering SEC_IDLE mode.

If the T1OSCEN bit is not set when the

SLEEP instruction is executed, the SLEEP

instruction will be ignored and entry to

SEC_IDLE mode will not occur. If the

Timer1 oscillator is enabled but not yet

running, peripheral clocks will be delayed

until the oscillator has started. In such

situations, initial oscillator operation is far

from stable and unpredictable operation

may result.

Peripheral

Program PC PC + 2

OSC1

Q3 Q4 Q1

CPU Clock

Clock

Counter

OSC1

Peripheral

Program PC

CPU Clock

Q1 Q3 Q4

Clock

Counter

Wake Event

TCSD

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 31
3.4.3 RC_IDLE MODE
In RC_IDLE mode, the CPU is disabled but the
peripherals continue to be clocked from the internal
oscillator block using the INTOSC multiplexer. This
mode allows for controllable power conservation during
Idle periods.
From RC_RUN, this mode is entered by setting the
IDLEN bit and executing a SLEEP instruction. If the
device is in another Run mode, first set IDLEN, then set
the SCS1 bit and execute SLEEP. Although its value is
ignored, it is recommended that SCS0 also be cleared;
this is to maintain software compatibility with future
devices. The INTOSC multiplexer may be used to
select a higher clock frequency by modifying the IRCF
bits before executing the SLEEP instruction. When the
clock source is switched to the INTOSC multiplexer, the
primary oscillator is shut down and the OSTS bit is
cleared.
If the IRCF bits are set to any non-zero value, or the
INTSRC bit is set, the INTOSC output is enabled. The
IOFS bit becomes set, after the INTOSC output
becomes stable, after an interval of TIOBST
(parameter 39, Table 22-10). Clocks to the peripherals
continue while the INTOSC source stabilizes. If the
IRCF bits were previously at a non-zero value, or
INTSRC was set before the SLEEP instruction was
executed and the INTOSC source was already stable,
the IOFS bit will remain set. If the IRCF bits and
INTSRC are all clear, the INTOSC output will not be
enabled, the IOFS bit will remain clear and there will be
no indication of the current clock source.
When a wake event occurs, the peripherals continue to
be clocked from the INTOSC multiplexer. After a delay of
TCSD following the wake event, the CPU begins
executing code being clocked by the INTOSC
multiplexer. The IDLEN and SCS bits are not affected by
the wake-up. The INTRC source will continue to run if
either the WDT or the Fail-Safe Clock Monitor is
enabled.
3.5 Exiting Idle and Sleep Modes
An exit from Sleep mode or any of the Idle modes is
triggered by an interrupt, a Reset or a WDT time-out.
This section discusses the triggers that cause exits
from power-managed modes. The clocking subsystem
actions are discussed in each of the power-managed
modes (see Section 3.2 “Run Modes”, Section 3.3
“Sleep Mode” and Section 3.4 “Idle Modes”). 
3.5.1 EXIT BY INTERRUPT
Any of the available interrupt sources can cause the
device to exit from an Idle mode or the Sleep mode to
a Run mode. To enable this functionality, an interrupt
source must be enabled by setting its enable bit in one
of the INTCON or PIE registers. The exit sequence is
initiated when the corresponding interrupt flag bit is set.
On all exits from Idle or Sleep modes by interrupt, code
execution branches to the interrupt vector if the GIE/
GIEH bit (INTCON<7>) is set. Otherwise, code execution
continues or resumes without branching (see
Section 10.0 “Interrupts”).
A fixed delay of interval TCSD following the wake event
is required when leaving Sleep and Idle modes. This
delay is required for the CPU to prepare for execution.
Instruction execution resumes on the first clock cycle
following this delay.
3.5.2 EXIT BY WDT TIME-OUT
A WDT time-out will cause different actions depending
on which power-managed mode the device is in when
the time-out occurs.
If the device is not executing code (all Idle modes and
Sleep mode), the time-out will result in an exit from the
power-managed mode (see Section 3.2 “Run
Modes” and Section 3.3 “Sleep Mode”). If the device
is executing code (all Run modes), the time-out will
result in a WDT Reset (see Section 19.2 “Watchdog
Timer (WDT)”). 
The WDT timer and postscaler are cleared by
executing a SLEEP or CLRWDT instruction, the loss of a
currently selected clock source (if the Fail-Safe Clock
Monitor is enabled) and modifying the IRCF bits in the
OSCCON register if the internal oscillator block is the
device clock source.
3.5.3 EXIT BY RESET
Normally, the device is held in Reset by the Oscillator
Start-up Timer (OST) until the primary clock becomes
ready. At that time, the OSTS bit is set and the device
begins executing code. If the internal oscillator block is
the new clock source, the IOFS bit is set instead. 
The exit delay time from Reset to the start of code
execution depends on both the clock sources before
and after the wake-up and the type of oscillator if the
new clock source is the primary clock. Exit delays are
summarized in Table 3-2.
Code execution can begin before the primary clock
becomes ready. If either the Two-Speed Start-up (see
Section 19.3 “Two-Speed Start-up”) or Fail-Safe
Clock Monitor (see Section 19.4 “Fail-Safe Clock
Monitor”) is enabled, the device may begin execution
as soon as the Reset source has cleared. Execution is
clocked by the INTOSC multiplexer driven by the
internal oscillator block. Execution is clocked by the
internal oscillator block until either the primary clock
becomes ready or a power-managed mode is entered
before the primary clock becomes ready; the primary
clock is then shut down.

PIC18F1230/1330

3.5.4 EXIT WITHOUT AN OSCILLATOR

START-UP DELAY

Certain exits from power-managed modes do not

invoke the OST at all. There are two cases:

• PRI_IDLE mode, where the primary clock source is

not stopped; and

• the primary clock source is not any of the LP, XT,

HS or HSPLL modes.

In these instances, the primary clock source either

does not require an oscillator start-up delay since it is

already running (PRI_IDLE), or normally does not

require an oscillator start-up delay (RC, EC and INTIO

Oscillator modes). However, a fixed delay of interval

TCSD following the wake event is still required when

leaving Sleep and Idle modes to allow the CPU to

prepare for execution. Instruction execution resumes

on the first clock cycle following this delay.

TABLE 3-2: EXIT DELAY ON WAKE-UP BY RESET FROM SLEEP MODE OR ANY IDLE MODE

(BY CLOCK SOURCES)

Clock Source

before Wake-up

Clock Source

after Wake-up Exit Delay Clock Ready Status

Bit (OSCCON)

Primary Device Clock

(PRI_IDLE mode)

LP, XT, HS

TCSD(1) OSTSHSPLL

EC, RC

INTOSC(2) IOFS

T1OSC

LP, XT, HS TOST(3)

OSTSHSPLL TOST + trc(3)

EC, RC TCSD(1)

INTOSC(1) TIOBST(4) IOFS

INTOSC(3)

LP, XT, HS TOST(4)

OSTSHSPLL TOST + trc(3)

EC, RC TCSD(1)

INTOSC(1) None IOFS

None

(Sleep mode)

LP, XT, HS TOST(3)

OSTSHSPLL TOST + trc(3)

EC, RC TCSD(1)

INTOSC(1) TIOBST(4) IOFS

Note 1: TCSD (parameter 38) is a required delay when waking from Sleep and all Idle modes and runs concurrently

with any other required delays (see Section 3.4 “Idle Modes”). On Reset, INTOSC defaults to 1 MHz.

2: Includes both the INTOSC 8 MHz source and postscaler derived frequencies.

3: TOST is the Oscillator Start-up Timer (parameter 32). trc is the PLL Lock-out Timer (parameter F12); it is

also designated as TPLL.

4: Execution continues during TIOBST (parameter 39), the INTOSC stabilization period.

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 33
4.0 RESET
The PIC18F1230/1330 devices differentiate between
various kinds of Reset: 
a) Power-on Reset (POR) 
b) MCLR Reset during normal operation
c) MCLR Reset during power-managed modes 
d) Watchdog Timer (WDT) Reset (during 
execution)
e) Programmable Brown-out Reset (BOR) 
f) RESET Instruction
g) Stack Full Reset
h) Stack Underflow Reset
This section discusses Resets generated by MCLR,
POR and BOR and covers the operation of the various
start-up timers. Stack Reset events are covered in
Section 5.1.2.4 “Stack Full and Underflow Resets”.
WDT Resets are covered in Section 19.2 “Watchdog
Timer (WDT)”.
A simplified block diagram of the On-Chip Reset Circuit
is shown in Figure 4-1.
4.1 RCON Register
Device Reset events are tracked through the RCON
register (Register 4-1). The lower five bits of the
register indicate that a specific Reset event has
occurred. In most cases, these bits can only be cleared
by the event and must be set by the application after
the event. The state of these flag bits, taken together,
can be read to indicate the type of Reset that just
occurred. This is described in more detail in
Section 4.6 “Reset State of Registers”.
The RCON register also has control bits for setting
interrupt priority (IPEN) and software control of the
BOR (SBOREN). Interrupt priority is discussed in
Section 10.0 “Interrupts”. BOR is covered in
Section 4.4 “Brown-out Reset (BOR)”.
FIGURE 4-1: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT        
External Reset
MCLR
VDD
OSC1
WDT
Time-out
VDD Rise
Detect
OST/PWRT
INTRC
(1)
 
POR Pulse
OST
10-Bit Ripple Counter
PWRT
11-Bit Ripple Counter
Enable OST(2)
Enable PWRT
Note 1: This is the INTRC source from the internal oscillator block and is separate from the RC oscillator of the CLKI pin.
2: See Table 4-2 for time-out situations.
Brown-out
Reset
BOREN
RESET
Instruction
Stack
Pointer
Stack Full/Underflow Reset
Sleep
( )_IDLE
1024 Cycles
65.5 ms
32 μs
MCLRE
S
RQ
Chip_Reset

PIC18F1230/1330

R/W-0 R/W-1(1) U-0 R/W-1 R-1 R-1 R/W-0(2) R/W-0

IPEN SBOREN —RITO PD POR BOR

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 IPEN: Interrupt Priority Enable bit

1 = Enable priority levels on interrupts

0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode)

bit 6 SBOREN: BOR Software Enable bit(1)

If BOREN1:BOREN0 = 01:

1 = BOR is enabled

0 = BOR is disabled

If BOREN1:BOREN0 = 00, 10 or 11:

Bit is disabled and read as ‘0’.

bit 5 Unimplemented: Read as ‘0’

bit 4 RI: RESET Instruction Flag bit

1 = The RESET instruction was not executed (set by firmware only)

0 = The RESET instruction was executed causing a device Reset (must be set in software after a

Brown-out Reset occurs)

bit 3 TO: Watchdog Time-out Flag bit

1 = Set by power-up, CLRWDT instruction or SLEEP instruction

0 = A WDT time-out occurred

bit 2 PD: Power-Down Detection Flag bit

1 = Set by power-up or by the CLRWDT instruction

0 = Set by execution of the SLEEP instruction

bit 1 POR: Power-on Reset Status bit(2)

1 = A Power-on Reset has not occurred (set by firmware only)

0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)

bit 0 BOR: Brown-out Reset Status bit

1 = A Brown-out Reset has not occurred (set by firmware only)

0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs)

Note 1: If SBOREN is enabled, its Reset state is ‘1’; otherwise, it is ‘0’.

2: The actual Reset value of POR is determined by the type of device Reset. See the notes following this

Note 1: It is recommended that the POR bit be set after a Power-on Reset has been detected so that subsequent

Power-on Resets may be detected.

2: Brown-out Reset is said to have occurred when BOR is ‘0’ and POR is ‘1’ (assuming that POR was set to

‘1’ by software immediately after a Power-on Reset).

PIC18F1230/1330

4.2 Master Clear (MCLR)

The MCLR pin provides a method for triggering an

external Reset of the device. A Reset is generated by

holding the pin low. These devices have a noise filter in

the MCLR Reset path which detects and ignores small

pulses.

The MCLR pin is not driven low by any internal Resets,

including the WDT.

In PIC18F1230/1330 devices, the MCLR input can be

disabled with the MCLRE Configuration bit. When

MCLR is disabled, the pin becomes a digital input. See

Section 9.1 “PORTA, TRISA and LATA Registers”

for more information.

4.3 Power-on Reset (POR)

A Power-on Reset pulse is generated on-chip

whenever VDD rises above a certain threshold. This

allows the device to start in the initialized state when

VDD is adequate for operation.

To take advantage of the POR circuitry, tie the MCLR

pin through a resistor (1 kΩ to 10 kΩ) to VDD. This will

eliminate external RC components usually needed to

create a Power-on Reset delay. A minimum rise rate for

VDD is specified (parameter D004). For a slow rise

time, see Figure 4-2.

When the device starts normal operation (i.e., exits the

Reset condition), device operating parameters

(voltage, frequency, temperature, etc.) must be met to

ensure operation. If these conditions are not met, the

device must be held in Reset until the operating

conditions are met.

Power-on Reset events are captured by the POR bit

(RCON<1>). The state of the bit is set to ‘0’ whenever

a Power-on Reset occurs; it does not change for any

other Reset event. POR is not reset to ‘1’ by any hard-

ware event. To capture multiple events, the user

manually resets the bit to ‘1’ in software following any

Power-on Reset.

FIGURE 4-2: EXTERNAL POWER-ON

RESET CIRCUIT (FOR

SLOW VDD POWER-UP)

Note 1: External Power-on Reset circuit is required

only if the VDD power-up slope is too slow.

The diode D helps discharge the capacitor

quickly when VDD powers down.

2: R < 40 kΩ is recommended to make sure that

the voltage drop across R does not violate

the device’s electrical specification.

3: R1 ≥ 1 kΩ will limit any current flowing into

MCLR from external capacitor C, in the event

of MCLR/VPP pin breakdown, due to

Electrostatic Discharge (ESD) or Electrical

Overstress (EOS).

VDD

MCLR

PIC18FXXXX

VDD

PIC18F1230/1330

4.4 Brown-out Reset (BOR)

PIC18F1230/1330 devices implement a BOR circuit that

provides the user with a number of configuration and

power-saving options. The BOR is controlled by the

BORV1:BORV0 and BOREN1:BOREN0 Configuration

bits. There are a total of four BOR configurations which

are summarized in Table 4-1.

The BOR threshold is set by the BORV1:BORV0 bits.

If BOR is enabled (any values of BOREN1:BOREN0

except ‘00’), any drop of VDD below VBOR (parameter

D005) for greater than TBOR (parameter 35) will reset

the device. A Reset may or may not occur if VDD falls

below VBOR for less than TBOR. The chip will remain in

Brown-out Reset until VDD rises above VBOR.

If the Power-up Timer is enabled, it will be invoked after

VDD rises above VBOR; it then will keep the chip in

Reset for an additional time delay, TPWRT

(parameter 33). If VDD drops below VBOR while the

Power-up Timer is running, the chip will go back into a

Brown-out Reset and the Power-up Timer will be

initialized. Once VDD rises above VBOR, the Power-up

Timer will execute the additional time delay.

BOR and the Power-on Timer (PWRT) are

independently configured. Enabling Brown-out Reset

does not automatically enable the PWRT.

4.4.1 SOFTWARE ENABLED BOR

When BOREN1:BOREN0 = 01, the BOR can be

enabled or disabled by the user in software. This is

done with the control bit, SBOREN (RCON<6>).

Setting SBOREN enables the BOR to function as

previously described. Clearing SBOREN disables the

BOR entirely. The SBOREN bit operates only in this

mode; otherwise it is read as ‘0’.

Placing the BOR under software control gives the user

the additional flexibility of tailoring the application to its

environment without having to reprogram the device to

change BOR configuration. It also allows the user to

tailor device power consumption in software by

eliminating the incremental current that the BOR

consumes. While the BOR current is typically very

small, it may have some impact in low-power

applications.

4.4.2 DETECTING BOR

When Brown-out Reset is enabled, the BOR bit always

resets to ‘0’ on any Brown-out Reset or Power-on

Reset event. This makes it difficult to determine if a

Brown-out Reset event has occurred just by reading

the state of BOR alone. A more reliable method is to

simultaneously check the state of both POR and BOR.

This assumes that the POR bit is reset to ‘1’ in software

immediately after any Power-on Reset event. If BOR is

‘0’ while POR is ‘1’, it can be reliably assumed that a

Brown-out Reset event has occurred.

4.4.3 DISABLING BOR IN SLEEP MODE

When BOREN1:BOREN0 = 10, the BOR remains

under hardware control and operates as previously

described. Whenever the device enters Sleep mode,

however, the BOR is automatically disabled. When the

device returns to any other operating mode, BOR is

automatically re-enabled.

This mode allows for applications to recover from

brown-out situations, while actively executing code,

when the device requires BOR protection the most. At

the same time, it saves additional power in Sleep mode

by eliminating the small incremental BOR current.

TABLE 4-1: BOR CONFIGURATIONS

Note: Even when BOR is under software control,

the Brown-out Reset voltage level is still

set by the BORV1:BORV0 Configuration

bits. It cannot be changed in software.

BOR Configuration Status of

SBOREN

(RCON<6>)

BOR Operation

BOREN1 BOREN0

00Unavailable BOR disabled; must be enabled by reprogramming the Configuration bits.

01Available BOR enabled in software; operation controlled by SBOREN.

10Unavailable BOR enabled in hardware in Run and Idle modes, disabled during

Sleep mode.

11Unavailable BOR enabled in hardware; must be disabled by reprogramming the

Configuration bits.

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 37
4.5 Device Reset Timers
PIC18F1230/1330 devices incorporate three separate
on-chip timers that help regulate the Power-on Reset
process. Their main function is to ensure that the device
clock is stable before code is executed. These timers
are:
• Power-up Timer (PWRT)
• Oscillator Start-up Timer (OST)
• PLL Lock Time-out
4.5.1 POWER-UP TIMER (PWRT)
The Power-up Timer (PWRT) of PIC18F1230/1330
devices is an 11-bit counter which uses the INTRC
source as the clock input. This yields an approximate
time interval of 2048 x 32 μs = 65.6 ms. While the
PWRT is counting, the device is held in Reset.
The power-up time delay depends on the INTRC clock
and will vary from chip to chip due to temperature and
process variation. See DC parameter 33 for details.
The PWRT is enabled by clearing the PWRTEN
Configuration bit. 
4.5.2 OSCILLATOR START-UP TIMER 
(OST)
The Oscillator Start-up Timer (OST) provides a
1024 oscillator cycle (from OSC1 input) delay after the
PWRT delay is over (parameter 33). This ensures that
the crystal oscillator or resonator has started and
stabilized.
The OST time-out is invoked only for XT, LP, HS and
HSPLL modes and only on Power-on Reset, or on exit
from most power-managed modes.
4.5.3 PLL LOCK TIME-OUT
With the PLL enabled in its PLL mode, the time-out
sequence following a Power-on Reset is slightly
different from other oscillator modes. A separate timer
is used to provide a fixed time-out that is sufficient for
the PLL to lock to the main oscillator frequency. This
PLL lock time-out (TPLL) is typically 2 ms and follows
the oscillator start-up time-out.
4.5.4 TIME-OUT SEQUENCE
On power-up, the time-out sequence is as follows:
1. After the POR pulse has cleared, PWRT time-out
is invoked (if enabled). 
2. Then, the OST is activated. 
The total time-out will vary based on oscillator
configuration and the status of the PWRT. Figure 4-3,
Figure 4-4, Figure 4-5, Figure 4-6 and Figure 4-7 all
depict time-out sequences on power-up, with the
Power-up Timer enabled and the device operating in
HS Oscillator mode. Figures 4-3 through 4-6 also apply
to devices operating in XT or LP modes. For devices in
RC mode and with the PWRT disabled, there will be no
time-out at all.
Since the time-outs occur from the POR pulse, if MCLR
is kept low long enough, all time-outs will expire.
Bringing MCLR high will begin execution immediately
(Figure 4-5). This is useful for testing purposes or to
synchronize more than one PIC18FXXXX device
operating in parallel.
TABLE 4-2: TIME-OUT IN VARIOUS SITUATIONS  
Oscillator
Configuration
Power-up(2) and Brown-out Reset Exit from 
Power-Managed Mode
PWRTEN = 0PWRTEN = 1
HSPLL 66 ms(1) + 1024 TOSC + 2 ms(2) 1024 TOSC + 2 ms(2) 1024 TOSC + 2 ms(2)
HS, XT, LP 66 ms(1) + 1024 TOSC 1024 TOSC 1024 TOSC
EC, ECIO 66 ms(1) ——
RC, RCIO 66 ms(1) ——
INTIO1, INTIO2 66 ms(1) ——
Note 1: 66 ms (65.5 ms) is the nominal Power-up Timer (PWRT) delay.
2: 2 ms is the nominal time required for the PLL to lock.

PIC18F1230/1330

FIGURE 4-3: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT)

FIGURE 4-4: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1

FIGURE 4-5: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2

TPWRT

TOST

VDD

MCLR

INTERNAL POR

PWRT TIME-OUT

OST TIME-OUT

INTERNAL RESET

TPWRT

TOST

VDD

MCLR

INTERNAL POR

PWRT TIME-OUT

OST TIME-OUT

INTERNAL RESET

VDD

MCLR

INTERNAL POR

PWRT TIME-OUT

OST TIME-OUT

INTERNAL RESET

TPWRT

TOST

PIC18F1230/1330

FIGURE 4-6: SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT)

FIGURE 4-7: TIME-OUT SEQUENCE ON POR W/PLL ENABLED (MCLR TIED TO VDD)

VDD

MCLR

INTERNAL POR

PWRT TIME-OUT

OST TIME-OUT

INTERNAL RESET

TPWRT

TOST

TPWRT

TOST

VDD

MCLR

INTERNAL POR

PWRT TIME-OUT

OST TIME-OUT

INTERNAL RESET

PLL TIME-OUT

TPLL

Note: TOST = 1024 clock cycles.

TPLL ≈ 2 ms max. First three stages of the PWRT timer.

PIC18F1230/1330

4.6 Reset State of Registers

Most registers are unaffected by a Reset. Their status

is unknown on POR and unchanged by all other

Resets. The other registers are forced to a “Reset

state” depending on the type of Reset that occurred.

Most registers are not affected by a WDT wake-up,

since this is viewed as the resumption of normal oper-

ation. Status bits from the RCON register, RI, TO, PD,

POR and BOR, are set or cleared differently in different

Reset situations, as indicated in Table 4-3. These bits

are used in software to determine the nature of the

Reset.

Table 4-4 describes the Reset states for all of the

Special Function Registers. These are categorized by

Power-on and Brown-out Resets, Master Clear and

WDT Resets and WDT wake-ups.

TABLE 4-3: STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION

FOR RCON REGISTER

Condition Program

Counter

RCON Register STKPTR Register

SBOREN RI TO PD POR BOR STKFUL STKUNF

Power-on Reset 0000h 1 11100 0 0

RESET Instruction 0000h u(2) 0uuuu u u

Brown-out Reset 0000h u(2) 111u0 u u

MCLR during Power-Managed

Run Modes

0000h u(2) u1uuu u u

MCLR during Power-Managed

Idle Modes and Sleep Mode

0000h u(2) u10uu u u

WDT Time-out during Full Power

or Power-Managed Run Mode

0000h u(2) u0uuu u u

MCLR during Full Power

Execution

0000h u(2) uuuuu u u

Stack Full Reset (STVREN = 1) 0000h u(2) uuuuu 1 u

Stack Underflow Reset

(STVREN = 1)

0000h u(2) uuuuu u 1

Stack Underflow Error (not an

actual Reset, STVREN = 0)

0000h u(2) uuuuu u 1

WDT Time-out during

Power-Managed Idle or

Sleep Modes

PC + 2 u(2) u00uu u u

Interrupt Exit from

Power-Managed Modes

PC + 2(1) u(2) uu0uu u u

Legend: u = unchanged

Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bit is set, the PC is loaded with the

interrupt vector (008h or 0018h).

2: Reset state is ‘1’ for POR and unchanged for all other Resets when software BOR is enabled

(BOREN1:BOREN0 Configuration bits = 01 and SBOREN = 1); otherwise, the Reset state is ‘0’.

PIC18F1230/1330

TABLE 4-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS

Devices

Power-on Reset,

Brown-out Reset

MCLR Resets,

WDT Reset,

RESET Instruction,

Stack Resets

Wake-up via WDT

or Interrupt

TOSU 1230 1330 ---0 0000 ---0 0000 ---0 uuuu(3)

TOSH 1230 1330 0000 0000 0000 0000 uuuu uuuu(3)

TOSL 1230 1330 0000 0000 0000 0000 uuuu uuuu(3)

STKPTR 1230 1330 00-0 0000 uu-0 0000 uu-u uuuu(3)

PCLATU 1230 1330 ---0 0000 ---0 0000 ---u uuuu

PCLATH 1230 1330 0000 0000 0000 0000 uuuu uuuu

PCL 1230 1330 0000 0000 0000 0000 PC + 2(2)

TBLPTRU 1230 1330 --00 0000 --00 0000 --uu uuuu

TBLPTRH 1230 1330 0000 0000 0000 0000 uuuu uuuu

TBLPTRL 1230 1330 0000 0000 0000 0000 uuuu uuuu

TABLAT 1230 1330 0000 0000 0000 0000 uuuu uuuu

PRODH 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

PRODL 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

INTCON 1230 1330 0000 000x 0000 000u uuuu uuuu(1)

INTCON2 1230 1330 1111 1111 1111 1111 uuuu uuuu(1)

INTCON3 1230 1330 1100 0000 1100 0000 uuuu uuuu(1)

INDF0 1230 1330 N/A N/A N/A

POSTINC0 1230 1330 N/A N/A N/A

POSTDEC0 1230 1330 N/A N/A N/A

PREINC0 1230 1330 N/A N/A N/A

PLUSW0 1230 1330 N/A N/A N/A

FSR0H 1230 1330 ---- 0000 ---- 0000 ---- uuuu

FSR0L 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

WREG 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

INDF1 1230 1330 N/A N/A N/A

POSTINC1 1230 1330 N/A N/A N/A

POSTDEC1 1230 1330 N/A N/A N/A

PREINC1 1230 1330 N/A N/A N/A

PLUSW1 1230 1330 N/A N/A N/A

FSR1H 1230 1330 ---- 0000 ---- 0000 ---- uuuu

FSR1L 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

BSR 1230 1330 ---- 0000 ---- 0000 ---- uuuu

Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition

Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).

2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the

interrupt vector (0008h or 0018h).

3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are

updated with the current value of the PC. The STKPTR is modified to point to the next location in the

hardware stack.

4: See Table 4-3 for Reset value for specific condition.

5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When

not enabled as PORTA pins, they are disabled and read as ‘0’.

6: Reset condition of PWMEN bits depends on the PWMPIN Configuration bit of CONFIG3L.

PIC18F1230/1330

INDF2 1230 1330 N/A N/A N/A

POSTINC2 1230 1330 N/A N/A N/A

POSTDEC2 1230 1330 N/A N/A N/A

PREINC2 1230 1330 N/A N/A N/A

PLUSW2 1230 1330 N/A N/A N/A

FSR2H 1230 1330 ---- 0000 ---- 0000 ---- uuuu

FSR2L 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

STATUS 1230 1330 ---x xxxx ---u uuuu ---u uuuu

TMR0H 1230 1330 0000 0000 0000 0000 uuuu uuuu

TMR0L 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

T0CON 1230 1330 1111 1111 1111 1111 uuuu uuuu

OSCCON 1230 1330 0100 q000 0100 q000 uuuu uuqu

LVDCON 1230 1330 --00 0101 --00 0101 --uu uuuu

WDTCON 1230 1330 ---- ---0 ---- ---0 ---- ---u

RCON(4) 1230 1330 0q-1 11q0 0q-q qquu uq-u qquu

TMR1H 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

TMR1L 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

T1CON 1230 1330 0000 0000 u0uu uuuu uuuu uuuu

ADRESH 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

ADRESL 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

ADCON0 1230 1330 0--- 0000 0--- 0000 u--- uuuu

ADCON1 1230 1330 ---0 1111 ---0 1111 ---u uuuu

ADCON2 1230 1330 0-00 0000 0-00 0000 u-uu uuuu

BAUDCON 1230 1330 01-0 0-00 01-0 0-00 uu-u u-uu

CVRCON 1230 1330 0-00 0000 0-00 0000 u-uu uuuu

CMCON 1230 1330 000- -000 000- -000 uuu- -uuu

SPBRGH 1230 1330 0000 0000 0000 0000 uuuu uuuu

SPBRG 1230 1330 0000 0000 0000 0000 uuuu uuuu

RCREG 1230 1330 0000 0000 0000 0000 uuuu uuuu

TXREG 1230 1330 0000 0000 0000 0000 uuuu uuuu

TXSTA 1230 1330 0000 0010 0000 0010 uuuu uuuu

RCSTA 1230 1330 0000 000x 0000 000x uuuu uuuu

TABLE 4-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)

Devices

Power-on Reset,

Brown-out Reset

MCLR Resets,

WDT Reset,

RESET Instruction,

Stack Resets

Wake-up via WDT

or Interrupt

Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition

Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).

2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the

interrupt vector (0008h or 0018h).

3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are

updated with the current value of the PC. The STKPTR is modified to point to the next location in the

hardware stack.

4: See Table 4-3 for Reset value for specific condition.

5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When

not enabled as PORTA pins, they are disabled and read as ‘0’.

6: Reset condition of PWMEN bits depends on the PWMPIN Configuration bit of CONFIG3L.

PIC18F1230/1330

EEADR 1230 1330 0000 0000 0000 0000 uuuu uuuu

EEDATA 1230 1330 0000 0000 0000 0000 uuuu uuuu

EECON2 1230 1330 0000 0000 0000 0000 0000 0000

EECON1 1230 1330 xx-0 x000 uu-0 u000 uu-0 u000

IPR3 1230 1330 ---1 ---- ---1 ---- ---u ----

PIR3 1230 1330 ---0 ---- ---0 ---- ---u ----

PIE3 1230 1330 ---0 ---- ---0 ---- ---u ----

IPIR2 1230 1330 1--1 -1-- 1--1 -1-- u--u -u--

PIR2 1230 1330 0--0 -0-- 0--0 -0-- u--u -u--(1)

PIE2 1230 1330 0--0 -0-- 0--0 -0-- u--u -u--

IPR1 1230 1330 -111 1111 -111 1111 -uuu uuuu

PIR1 1230 1330 -000 0000 -000 0000 -uuu uuuu(1)

PIE1 1230 1330 -000 0000 -000 0000 -uuu uuuu

OSCTUNE 1230 1330 00-0 0000 00-0 0000 uu-u uuuu

PTCON0 1230 1330 0000 0000 uuuu uuuu uuuu uuuu

PTCON1 1230 1330 00-- ---- 00-- ---- uu-- ----

PTMRL 1230 1330 0000 0000 0000 0000 uuuu uuuu

PTMRH 1230 1330 ---- 0000 ---- 0000 ---- uuuu

PTPERL 1230 1330 1111 1111 1111 1111 uuuu uuuu

PTPERH 1230 1330 ---- 1111 ---- 1111 ---- uuuu

TRISB 1230 1330 1111 1111 1111 1111 uuuu uuuu

TRISA 1230 1330 1111 1111(5) 1111 1111(5) uuuu uuuu(5)

PDC0L 1230 1330 0000 0000 0000 0000 uuuu uuuu

PDC0H 1230 1330 --00 0000 --00 0000 --uu uuuu

PDC1L 1230 1330 0000 0000 0000 0000 uuuu uuuu

PDC1H 1230 1330 --00 0000 --00 0000 --uu uuuu

PDC2L 1230 1330 0000 0000 0000 0000 uuuu uuuu

PDC2H 1230 1330 --00 0000 --00 0000 --uu uuuu

FLTCONFIG 1230 1330 0--- -000 0--- -000 u--- -uuu

LATB 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

LATA 1230 1330 xxxx xxxx(5) uuuu uuuu(5) uuuu uuuu(5)

SEVTCMPL 1230 1330 0000 0000 0000 0000 uuuu uuuu

TABLE 4-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)

Devices

Power-on Reset,

Brown-out Reset

MCLR Resets,

WDT Reset,

RESET Instruction,

Stack Resets

Wake-up via WDT

or Interrupt

Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition

Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).

2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the

interrupt vector (0008h or 0018h).

3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are

updated with the current value of the PC. The STKPTR is modified to point to the next location in the

hardware stack.

4: See Table 4-3 for Reset value for specific condition.

5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When

not enabled as PORTA pins, they are disabled and read as ‘0’.

6: Reset condition of PWMEN bits depends on the PWMPIN Configuration bit of CONFIG3L.

PIC18F1230/1330

SEVTCMPH 1230 1330 ---- 0000 ---- 0000 ---- uuuu

PWMCON0 1230 1330 -100 -000(6) -100 -000(6) -uuu -uuu(6)

-000 -000(6) -000 -000(6) -uuu -uuu(6)

PWMCON1 1230 1330 0000 0-00 0000 0-00 uuuu u-uu

DTCON 1230 1330 0000 0000 0000 0000 uuuu uuuu

OVDCOND 1230 1330 --11 1111 --11 1111 --uu uuuu

OVDCONS 1230 1330 --00 0000 --00 0000 --uu uuuu

PORTB 1230 1330 xxxx xxxx uuuu uuuu uuuu uuuu

PORTA 1230 1330 xx0x xxxx(5) uu0u uuuu(5) uuuu uuuu(5)

TABLE 4-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)

Devices

Power-on Reset,

Brown-out Reset

MCLR Resets,

WDT Reset,

RESET Instruction,

Stack Resets

Wake-up via WDT

or Interrupt

Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition

Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).

2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the

interrupt vector (0008h or 0018h).

3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are

updated with the current value of the PC. The STKPTR is modified to point to the next location in the

hardware stack.

4: See Table 4-3 for Reset value for specific condition.

5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When

not enabled as PORTA pins, they are disabled and read as ‘0’.

6: Reset condition of PWMEN bits depends on the PWMPIN Configuration bit of CONFIG3L.

PIC18F1230/1330

5.0 MEMORY ORGANIZATION

There are three types of memory in PIC18 Enhanced

microcontroller devices:

• Program Memory

• Data RAM

• Data EEPROM

As Harvard architecture devices, the data and program

memories use separate busses; this allows for

concurrent access of the two memory spaces. The data

EEPROM, for practical purposes, can be regarded as

a peripheral device, since it is addressed and accessed

through a set of control registers.

Additional detailed information on the operation of the

Flash program memory is provided in Section 6.0

“Flash Program Memory”. Data EEPROM is

discussed separately in Section 7.0 “Data EEPROM

Memory”.

5.1 Program Memory Organization

PIC18 microcontrollers implement a 21-bit program

counter, which is capable of addressing a 2-Mbyte

program memory space. Accessing a location between

the upper boundary of the physically implemented

memory and the 2-Mbyte address will return all ‘0’s (a

NOP instruction).

The PIC18F1230 has 4 Kbytes of Flash memory and

can store up to 2,048 single-word instructions. The

PIC18F1330 has 8 Kbytes of Flash memory and can

store up to 4,096 single-word instructions.

PIC18 devices have two interrupt vectors. The Reset

vector address is at 0000h and the interrupt vector

addresses are at 0008h and 0018h.

The program memory maps for PIC18F1230 and

PIC18F1330 devices are shown in Figure 5-1.

FIGURE 5-1: PROGRAM MEMORY MAP AND STACK FOR PIC18F1230/1330 DEVICES

PC<20:0>

Stack Level 1

•

Stack Level 31

Reset Vector

Low-Priority Interrupt Vector

•

CALL,RCALL,RETURN

RETFIE,RETLW

0000h

0018h

On-Chip

Program Memory

High-Priority Interrupt Vector 0008h

User Memory Space

1FFFFFh

1000h

0FFFh

Read ‘0’

200000h

PC<20:0>

Stack Level 1

•

Stack Level 31

Reset Vector

Low-Priority Interrupt Vector

•

CALL,RCALL,RETURN

RETFIE,RETLW

0000h

0018h

2000h

1FFFh

On-Chip

Program Memory

High-Priority Interrupt Vector 0008h

User Memory Space

Read ‘0’

1FFFFFh

200000h

PIC18F1230 PIC18F1330

PIC18F1230/1330

5.1.1 PROGRAM COUNTER

The Program Counter (PC) specifies the address of the

instruction to fetch for execution. The PC is 21 bits wide

and is contained in three separate 8-bit registers. The

low byte, known as the PCL register, is both readable

and writable. The high byte, or PCH register, contains

the PC<15:8> bits; it is not directly readable or writable.

Updates to the PCH register are performed through the

PCLATH register. The upper byte is called PCU. This

directly readable or writable. Updates to the PCU

The contents of PCLATH and PCLATU are transferred

to the program counter by any operation that writes to

the PCL. Similarly, the upper two bytes of the program

counter are transferred to PCLATH and PCLATU by an

operation that reads the PCL. This is useful for

computed offsets to the PC (see Section 5.1.4.1

“Computed GOTO”).

The PC addresses bytes in the program memory. To

prevent the PC from becoming misaligned with word

instructions, the Least Significant bit of PCL is fixed to

a value of ‘0’. The PC increments by 2 to address

sequential instructions in the program memory.

The CALL, RCALL, GOTO and program branch

instructions write to the program counter directly. For

these instructions, the contents of PCLATH and

PCLATU are not transferred to the program counter.

5.1.2 RETURN ADDRESS STACK

The return address stack allows any combination of up

to 31 program calls and interrupts to occur. The PC is

pushed onto the stack when a CALL or RCALL

instruction is executed or an interrupt is Acknowledged.

The PC value is pulled off the stack on a RETURN,

RETLW or a RETFIE instruction. PCLATU and PCLATH

are not affected by any of the RETURN or CALL

instructions.

The stack operates as a 31-word by 21-bit RAM and a

5-bit Stack Pointer, STKPTR. The stack space is not

part of either program or data space. The Stack Pointer

is readable and writable and the address on the top of

the stack is readable and writable through the Top-of-

Stack Special Function Registers. Data can also be

pushed to, or popped from the stack, using these

registers.

A CALL type instruction causes a push onto the stack;

the Stack Pointer is first incremented and the location

pointed to by the Stack Pointer is written with the

contents of the PC (already pointing to the instruction

following the CALL). A RETURN type instruction causes

a pop from the stack; the contents of the location

pointed to by the STKPTR are transferred to the PC

and then the Stack Pointer is decremented.

The Stack Pointer is initialized to ‘00000’ after all

Resets. There is no RAM associated with the location

corresponding to a Stack Pointer value of ‘00000’; this

is only a Reset value. Status bits indicate if the stack is

full, has overflowed or has underflowed.

5.1.2.1 Top-of-Stack Access

Only the top of the return address stack (TOS) is

readable and writable. A set of three registers,

TOSU:TOSH:TOSL, hold the contents of the stack

location pointed to by the STKPTR register (Figure 5-2).

This allows users to implement a software stack if

necessary. After a CALL, RCALL or interrupt, the

software can read the pushed value by reading the

TOSU:TOSH:TOSL registers. These values can be

placed on a user-defined software stack. At return time,

the software can return these values to

TOSU:TOSH:TOSL and do a return.

The user must disable the global interrupt enable bits

while accessing the stack to prevent inadvertent stack

corruption.

FIGURE 5-2: RETURN ADDRESS STACK AND ASSOCIATED REGISTERS

00011

001A34h

11111

11110

11101

00010

00001

00000

00010

Return Address Stack <20:0>

To p - o f - St a c k

000D58h

STKPTR<4:0>

Top-of-Stack Registers Stack Pointer

TOSLTOSHTOSU

34h1Ah00h

PIC18F1230/1330

5.1.2.2 Return Stack Pointer (STKPTR)

The STKPTR register (Register 5-1) contains the Stack

Pointer value, the STKFUL (Stack Full) status bit and

the STKUNF (Stack Underflow) status bits. The value

of the Stack Pointer can be 0 through 31. The Stack

Pointer increments before values are pushed onto the

stack and decrements after values are popped off the

stack. On Reset, the Stack Pointer value will be zero.

The user may read and write the Stack Pointer value.

This feature can be used by a Real-Time Operating

System (RTOS) for return stack maintenance.

After the PC is pushed onto the stack 31 times (without

popping any values off the stack), the STKFUL bit is

set. The STKFUL bit is cleared by software or by a

POR.

The action that takes place when the stack becomes

full depends on the state of the STVREN (Stack

Overflow Reset Enable) Configuration bit. (Refer to

Section 19.1 “Configuration Bits” for a description of

the device Configuration bits.) If STVREN is set

(default), the 31st push will push the (PC + 2) value

onto the stack, set the STKFUL bit and reset the

device. The STKFUL bit will remain set and the Stack

Pointer will be set to zero.

If STVREN is cleared, the STKFUL bit will be set on the

31st push and the Stack Pointer will increment to 31.

Any additional pushes will not overwrite the 31st push

and STKPTR will remain at 31.

When the stack has been popped enough times to

unload the stack, the next pop will return a value of zero

to the PC and sets the STKUNF bit, while the Stack

Pointer remains at zero. The STKUNF bit will remain

set until cleared by software or until a POR occurs.

5.1.2.3 PUSH and POP Instructions

Since the Top-of-Stack is readable and writable, the

ability to push values onto the stack and pull values off

the stack, without disturbing normal program execu-

tion, is a desirable feature. The PIC18 instruction set

includes two instructions, PUSH and POP, that permit

the TOS to be manipulated under software control.

TOSU, TOSH and TOSL can be modified to place data

or a return address on the stack.

The PUSH instruction places the current PC value onto

the stack. This increments the Stack Pointer and loads

the current PC value onto the stack.

The POP instruction discards the current TOS by

decrementing the Stack Pointer. The previous value

pushed onto the stack then becomes the TOS value.

Note: Returning a value of zero to the PC on an

underflow has the effect of vectoring the

program to the Reset vector, where the

stack conditions can be verified and

appropriate actions can be taken. This is

not the same as a Reset, as the contents

of the SFRs are not affected.

R/C-0 R/C-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

STKFUL(1) STKUNF(1) — SP4 SP3 SP2 SP1 SP0

bit 7 bit 0

Legend: C = Clearable bit

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 STKFUL: Stack Full Flag bit(1)

1 = Stack became full or overflowed

0 = Stack has not become full or overflowed

bit 6 STKUNF: Stack Underflow Flag bit(1)

1 = Stack underflow occurred

0 = Stack underflow did not occur

bit 5 Unimplemented: Read as ‘0’

bit 4-0 SP4:SP0: Stack Pointer Location bits

Note 1: Bit 7 and bit 6 are cleared by user software or by a POR.

PIC18F1230/1330

5.1.2.4 Stack Full and Underflow Resets

Device Resets on stack overflow and stack underflow

conditions are enabled by setting the STVREN bit in

Configuration Register 4L. When STVREN is set, a full

or underflow will set the appropriate STKFUL or

STKUNF bit and then cause a device Reset. When

STVREN is cleared, a full or underflow condition will set

the appropriate STKFUL or STKUNF bit but not cause

a device Reset. The STKFUL or STKUNF bit is cleared

by the user software or a Power-on Reset.

5.1.3 FAST REGISTER STACK

A Fast Register Stack is provided for the STATUS,

WREG and BSR registers, to provide a “fast return”

option for interrupts. The stack for each register is only

one level deep and is neither readable nor writable. It is

loaded with the current value of the corresponding

interrupt sources will push values into the Stack

registers. The values in the registers are then loaded

back into their associated registers if the

RETFIE, FAST instruction is used to return from the

interrupt.

If both low and high-priority interrupts are enabled, the

Stack registers cannot be used reliably to return from

low-priority interrupts. If a high-priority interrupt occurs

while servicing a low-priority interrupt, the Stack regis-

ter values stored by the low-priority interrupt will be

overwritten. In these cases, users must save the key

registers in software during a low-priority interrupt.

If interrupt priority is not used, all interrupts may use the

Fast Register Stack for returns from interrupt. If no

interrupts are used, the Fast Register Stack can be

used to restore the STATUS, WREG and BSR regis-

ters at the end of a subroutine call. To use the Fast

label,FAST instruction must be executed to save the

STATUS, WREG and BSR registers to the Fast Regis-

ter Stack. A RETURN, FAST instruction is then exe-

cuted to restore these registers from the Fast Register

Stack.

Example 5-1 shows a source code example that uses

the Fast Register Stack during a subroutine call and

return.

EXAMPLE 5-1: FAST REGISTER STACK

CODE EXAMPLE

5.1.4 LOOK-UP TABLES IN PROGRAM

MEMORY

There may be programming situations that require the

creation of data structures, or look-up tables, in

program memory. For PIC18 devices, look-up tables

can be implemented in two ways:

• Computed GOTO

• Table Reads

5.1.4.1 Computed GOTO

A computed GOTO is accomplished by adding an offset

to the program counter. An example is shown in

Example 5-2.

A look-up table can be formed with an ADDWF PCL

instruction and a group of RETLW nn instructions. The

W register is loaded with an offset into the table before

executing a call to that table. The first instruction of the

called routine is the ADDWF PCL instruction. The next

instruction executed will be one of the RETLW nn

instructions that returns the value ‘nn’ to the calling

function.

The offset value (in WREG) specifies the number of

bytes that the program counter should advance and

should be multiples of 2 (LSb = 0).

In this method, only one data byte may be stored in

each instruction location and room on the return

address stack is required.

EXAMPLE 5-2: COMPUTED GOTO USING

AN OFFSET VALUE

5.1.4.2 Table Reads and Table Writes

A better method of storing data in program memory

allows two bytes of data to be stored in each instruction

location.

Look-up table data may be stored two bytes per

program word by using table reads and writes. The

Table Pointer (TBLPTR) register specifies the byte

address and the Table Latch (TABLAT) register

contains the data that is read from or written to program

memory. Data is transferred to or from program

memory one byte at a time.

Table read and table write operations are discussed

further in Section 6.1 “Table Reads and Table

Writes”.

CALL SUB1, FAST ;STATUS, WREG, BSR

;SAVED IN FAST REGISTER

;STACK

•

SUB1 •

•

RETURN, FAST ;RESTORE VALUES SAVED

;IN FAST REGISTER STACK

MOVF OFFSET, W

CALL TABLE

ORG nn00h

TABLE ADDWF PCL

RETLW nnh

PIC18F1230/1330

5.2 PIC18 Instruction Cycle

5.2.1 CLOCKING SCHEME

The microcontroller clock input, whether from an

internal or external source, is internally divided by four

to generate four non-overlapping quadrature clocks

(Q1, Q2, Q3 and Q4). Internally, the program counter is

incremented on every Q1; the instruction is fetched

from the program memory and latched into the Instruc-

tion Register (IR) during Q4. The instruction is decoded

and executed during the following Q1 through Q4. The

clocks and instruction execution flow are shown in

Figure 5-3.

5.2.2 INSTRUCTION FLOW/PIPELINING

An “Instruction Cycle” consists of four Q cycles: Q1

through Q4. The instruction fetch and execute are

pipelined in such a manner that a fetch takes one

instruction cycle, while the decode and execute take

another instruction cycle. However, due to the

pipelining, each instruction effectively executes in one

cycle. If an instruction causes the program counter to

change (e.g., GOTO), then two cycles are required to

complete the instruction (Example 5-3).

A fetch cycle begins with the Program Counter (PC)

incrementing in Q1.

In the execution cycle, the fetched instruction is latched

into the Instruction Register (IR) in cycle Q1. This

instruction is then decoded and executed during the

Q2, Q3 and Q4 cycles. Data memory is read during Q2

(operand read) and written during Q4 (destination

write).

FIGURE 5-3: CLOCK/INSTRUCTION CYCLE

EXAMPLE 5-3: INSTRUCTION PIPELINE FLOW

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

OSC1

OSC2/CLKO

(RC mode)

PC PC + 2 PC + 4

Fetch INST (PC)

Execute INST (PC – 2)

Fetch INST (PC + 2)

Execute INST (PC)

Fetch INST (PC + 4)

Execute INST (PC + 2)

Internal

Phase

Clock

All instructions are single cycle, except for any program branches. These take two cycles since the fetch instruction

is “flushed” from the pipeline while the new instruction is being fetched and then executed.

TCY0TCY1TCY2TCY3TCY4TCY5

1. MOVLW 55h Fetch 1 Execute 1

2. MOVWF PORTB Fetch 2 Execute 2

3. BRA SUB_1 Fetch 3 Execute 3

4. BSF PORTA, BIT3 (Forced NOP) Fetch 4 Flush (NOP)

5. Instruction @ address SUB_1 Fetch SUB_1 Execute SUB_1

PIC18F1230/1330

5.2.3 INSTRUCTIONS IN PROGRAM

MEMORY

The program memory is addressed in bytes.

Instructions are stored as two bytes or four bytes in

program memory. The Least Significant Byte of an

instruction word is always stored in a program memory

location with an even address (LSb = 0). To maintain

alignment with instruction boundaries, the PC

increments in steps of 2 and the LSb will always read

‘0’ (see Section 5.1.1 “Program Counter”).

Figure 5-4 shows an example of how instruction words

are stored in the program memory.

The CALL and GOTO instructions have the absolute

program memory address embedded into the

instruction. Since instructions are always stored on word

boundaries, the data contained in the instruction is a

word address. The word address is written to PC<20:1>,

which accesses the desired byte address in program

memory. Instruction #2 in Figure 5-4 shows how the

instruction, GOTO 0006h, is encoded in the program

memory. Program branch instructions, which encode a

relative address offset, operate in the same manner. The

offset value stored in a branch instruction represents the

number of single-word instructions that the PC will be

offset by. Section 21.0 “Instruction Set Summary”

provides further details of the instruction set.

FIGURE 5-4: INSTRUCTIONS IN PROGRAM MEMORY

5.2.4 TWO-WORD INSTRUCTIONS

The standard PIC18 instruction set has four two-word

instructions: CALL, MOVFF, GOTO and LSFR. In all

cases, the second word of the instructions always has

‘1111’ as its four Most Significant bits; the other 12 bits

are literal data, usually a data memory address.

The use of ‘1111’ in the 4 MSbs of an instruction

specifies a special form of NOP. If the instruction is

executed in proper sequence – immediately after the

first word – the data in the second word is accessed

and used by the instruction sequence. If the first word

is skipped for some reason and the second word is

executed by itself, a NOP is executed instead. This is

necessary for cases when the two-word instruction is

preceded by a conditional instruction that changes the

PC. Example 5-4 shows how this works.

EXAMPLE 5-4: TWO-WORD INSTRUCTIONS

Word Address

LSB = 1LSB = 0↓

Program Memory

Byte Locations →

000000h

000002h

000004h

000006h

Instruction 1: MOVLW 055h 0Fh 55h 000008h

Instruction 2: GOTO 0006h EFh 03h 00000Ah

F0h 00h 00000Ch

Instruction 3: MOVFF 123h, 456h C1h 23h 00000Eh

F4h 56h 000010h

000012h

000014h

Note: See Section 5.6 “PIC18 Instruction

Execution and the Extended Instruc-

tion Set” for information on two-word

instructions in the extended instruction set.

CASE 1:

Object Code Source Code

0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0?

1100 0001 0010 0011 MOVFF REG1, REG2 ; No, skip this word

1111 0100 0101 0110 ; Execute this word as a NOP

0010 0100 0000 0000 ADDWF REG3 ; continue code

CASE 2:

Object Code Source Code

0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0?

1100 0001 0010 0011 MOVFF REG1, REG2 ; Yes, execute this word

1111 0100 0101 0110 ; 2nd word of instruction

0010 0100 0000 0000 ADDWF REG3 ; continue code

PIC18F1230/1330

5.3 Data Memory Organization

The data memory in PIC18 devices is implemented as

static RAM. Each register in the data memory has a

12-bit address, allowing up to 4096 bytes of data

memory. The memory space is divided into as many as

16 banks that contain 256 bytes each; PIC18F1230/

1330 devices implement 1 bank. Figure 5-5 shows the

data memory organization for the PIC18F1230/1330

devices.

The data memory contains Special Function Registers

(SFRs) and General Purpose Registers (GPRs). The

SFRs are used for control and status of the controller

and peripheral functions, while GPRs are used for data

storage and scratchpad operations in the user’s

application. Any read of an unimplemented location will

read as ‘0’s.

The instruction set and architecture allow operations

across all banks. The entire data memory may be

accessed by Direct, Indirect or Indexed Addressing

modes. Addressing modes are discussed later in this

subsection.

To ensure that commonly used registers (SFRs and

select GPRs) can be accessed in a single cycle, PIC18

devices implement an Access Bank. This is a 256-byte

memory space that provides fast access to SFRs and

the lower portion of GPR Bank 0 without using the

BSR. Section 5.3.2 “Access Bank” provides a

detailed description of the Access RAM.

5.3.1 BANK SELECT REGISTER (BSR)

Large areas of data memory require an efficient

addressing scheme to make rapid access to any

address possible. Ideally, this means that an entire

address does not need to be provided for each read or

write operation. For PIC18 devices, this is

accomplished with a RAM banking scheme. This

divides the memory space into 16 contiguous banks of

256 bytes. Depending on the instruction, each location

can be addressed directly by its full 12-bit address, or

an 8-bit low-order address and a 4-bit Bank Pointer.

Most instructions in the PIC18 instruction set make use

of the Bank Pointer, known as the Bank Select Register

(BSR). This SFR holds the four Most Significant bits of

a location’s address; the instruction itself includes the

eight Least Significant bits. Only the four lower bits of

the BSR are implemented (BSR3:BSR0). The upper

four bits are unused; they will always read ‘0’ and can-

not be written to. The BSR can be loaded directly by

using the MOVLB instruction.

The value of the BSR indicates the bank in data

memory. The 8 bits in the instruction show the location

in the bank and can be thought of as an offset from the

bank’s lower boundary. The relationship between the

BSR’s value and the bank division in data memory is

shown in Figure 5-6.

Since up to 16 registers may share the same low-order

address, the user must always be careful to ensure that

the proper bank is selected before performing a data

read or write. For example, writing what should be

program data to an 8-bit address of F9h, while the BSR

is 0Fh, will end up resetting the program counter.

While any bank can be selected, only those banks that

are actually implemented can be read or written to.

Writes to unimplemented banks are ignored, while

reads from unimplemented banks will return ‘0’s. Even

so, the STATUS register will still be affected as if the

operation was successful. The data memory map in

Figure 5-5 indicates which banks are implemented.

In the core PIC18 instruction set, only the MOVFF

instruction fully specifies the 12-bit address of the

source and target registers. This instruction ignores the

BSR completely when it executes. All other instructions

include only the low-order address as an operand and

must use either the BSR or the Access Bank to locate

their target registers.

Note: The operation of some aspects of data

memory are changed when the PIC18

extended instruction set is enabled. See

Section 5.5 “Data Memory and the

Extended Instruction Set” for more

information.

PIC18F1230/1330

FIGURE 5-5: DATA MEMORY MAP FOR PIC18F1230/1330 DEVICES

Bank 0

Bank 14

Bank 15

Data Memory Map

BSR<3:0>

= 0000

= 1111

080h

07Fh

F80h

FFFh

00h

7Fh

80h

FFh

Access Bank

When a = 0:

The BSR is ignored and the

Access Bank is used.

The first 128 bytes are

general purpose RAM

(from Bank 0).

The second 128 bytes are

Special Function Registers

(from Bank 15).

When a = 1:

The BSR specifies the Bank

used by the instruction.

F7Fh

F00h

EFFh

0FFh

000h

Access RAM

FFh

00h

FFh

00h

GPR

SFR

Access RAM High

Access RAM Low

Bank 1

(SFRs)

= 0001

= 1110

Unused

Read ‘00h’

Unused

Read ‘00h’

PIC18F1230/1330

FIGURE 5-6: USE OF THE BANK SELECT REGISTER (DIRECT ADDRESSING)

5.3.2 ACCESS BANK

While the use of the BSR with an embedded 8-bit

address allows users to address the entire range of

data memory, it also means that the user must always

ensure that the correct bank is selected. Otherwise,

data may be read from or written to the wrong location.

This can be disastrous if a GPR is the intended target

of an operation, but an SFR is written to instead.

Verifying and/or changing the BSR for each read or

write to data memory can become very inefficient.

To streamline access for the most commonly used data

memory locations, the data memory is configured with

an Access Bank, which allows users to access a

mapped block of memory without specifying a BSR.

The Access Bank consists of the first 128 bytes of

memory (00h-7Fh) in Bank 0 and the last 128 bytes of

memory (80h-FFh) in Block 15. The lower half is known

as the “Access RAM” and is composed of GPRs. The

upper half is where the device’s SFRs are mapped.

These two areas are mapped contiguously in the

Access Bank and can be addressed in a linear fashion

by an 8-bit address (Figure 5-5).

The Access Bank is used by core PIC18 instructions

that include the Access RAM bit (the ‘a’ parameter in

the instruction). When ‘a’ is equal to ‘1’, the instruction

uses the BSR and the 8-bit address included in the

opcode for the data memory address. When ‘a’ is ‘0’,

however, the instruction is forced to use the Access

Bank address map; the current value of the BSR is

ignored entirely.

Using this “forced” addressing allows the instruction to

operate on a data address in a single cycle without

updating the BSR first. For 8-bit addresses of 80h and

above, this means that users can evaluate and operate

on SFRs more efficiently. The Access RAM below 80h

is a good place for data values that the user might need

to access rapidly, such as immediate computational

results or common program variables. Access RAM

also allows for faster and more code efficient context

saving and switching of variables.

The mapping of the Access Bank is slightly different

when the extended instruction set is enabled (XINST

Configuration bit = 1). This is discussed in more detail

in Section 5.5.3 “Mapping the Access Bank in

Indexed Literal Offset Addressing Mode”.

5.3.3 GENERAL PURPOSE

PIC18 devices may have banked memory in the GPR

area. This is data RAM which is available for use by all

instructions. GPRs start at the bottom of Bank 0

(address 000h) and grow upwards towards the bottom of

the SFR area. GPRs are not initialized by a Power-on

Reset and are unchanged on all other Resets.

Note 1: The Access RAM bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to

the registers of the Access Bank.

2: The MOVFF instruction embeds the entire 12-bit address in the instruction.

Data Memory

Bank Select(2)

From Opcode(2)

0000 000h

100h

F00h

E00h

FFFh

Bank 0

Bank 14

Bank 15

00h

FFh

00h

FFh

00h

FFh

Bank 1

through

Bank 13

0000 11111 111

BSR(1)

PIC18F1230/1330

5.3.4 SPECIAL FUNCTION REGISTERS

The Special Function Registers (SFRs) are registers

used by the CPU and peripheral modules for controlling

the desired operation of the device. These registers are

implemented as static RAM. SFRs start at the top of

data memory (FFFh) and extend downward to occupy

the top half of Bank 15 (F80h to FFFh). A list of these

registers is given in Table 5-1 and Table 5-2.

The SFRs can be classified into two sets: those

associated with the “core” device functionality (ALU,

Resets and interrupts) and those related to the

peripheral functions. The Reset and Interrupt registers

are described in their respective chapters, while the

ALU’s STATUS register is described later in this section.

Registers related to the operation of a peripheral feature

are described in the chapter for that peripheral.

The SFRs are typically distributed among the

peripherals whose functions they control. Unused SFR

locations are unimplemented and read as ‘0’s.

TABLE 5-1: SPECIAL FUNCTION REGISTER MAP FOR PIC18F1230/1330 DEVICES

Address Name Address Name Address Name Address Name

FFFh TOSU FDFh INDF2(1) FBFh —(2) F9Fh IPR1

FFEh TOSH FDEh POSTINC2(1) FBEh —(2) F9Eh PIR1

FFDh TOSL FDDh POSTDEC2(1) FBDh —(2) F9Dh PIE1

FFCh STKPTR FDCh PREINC2(1) FBCh —(2) F9Ch —(2)

FFBh PCLATU FDBh PLUSW2(1) FBBh —(2) F9Bh OSCTUNE

FFAh PCLATH FDAh FSR2H FBAh —(2) F9Ah PTCON0

FF9h PCL FD9h FSR2L FB9h —(2) F99h PTCON1

FF8h TBLPTRU FD8h STATUS FB8h BAUDCON F98h PTMRL

FF7h TBLPTRH FD7h TMR0H FB7h —(2) F97h PTMRH

FF6h TBLPTRL FD6h TMR0L FB6h —(2) F96h PTPERL

FF5h TABLAT FD5h T0CON FB5h CVRCON F95h PTPERH

FF4h PRODH FD4h —(2) FB4h CMCON F94h —(2)

FF3h PRODL FD3h OSCCON FB3h —(2) F93h TRISB

FF2h INTCON FD2h LVDCON FB2h —(2) F92h TRISA

FF1h INTCON2 FD1h WDTCON FB1h —(2) F91h PDC0L

FF0h INTCON3 FD0h RCON FB0h SPBRGH F90h PDC0H

FEFh INDF0(1) FCFh TMR1H FAFh SPBRG F8Fh PDC1L

FEEh POSTINC0(1) FCEh TMR1L FAEh RCREG F8Eh PDC1H

FEDh POSTDEC0(1) FCDh T1CON FADh TXREG F8Dh PDC2L

FECh PREINC0(1) FCCh —(2) FACh TXSTA F8Ch PDC2H

FEBh PLUSW0(1) FCBh —(2) FABh RCSTA F8Bh FLTCONFIG

FEAh FSR0H FCAh —(2) FAAh —(2) F8Ah LATB

FE9h FSR0L FC9h —(2) FA9h EEADR F89h LATA

FE8h WREG FC8h —(2) FA8h EEDATA F88h SEVTCMPL

FE7h INDF1(1) FC7h —(2) FA7h EECON2(1) F87h SEVTCMPH

FE6h POSTINC1(1) FC6h —(2) FA6h EECON1 F86h PWMCON0

FE5h POSTDEC1(1) FC5h —(2) FA5h IPR3 F85h PWMCON1

FE4h PREINC1(1) FC4h ADRESH FA4h PIR3 F84h DTCON

FE3h PLUSW1(1) FC3h ADRESL FA3h PIE3 F83h OVDCOND

FE2h FSR1H FC2h ADCON0 FA2h IPR2 F82h OVDCONS

FE1h FSR1L FC1h ADCON1 FA1h PIR2 F81h PORTB

FE0h BSR FC0h ADCON2 FA0h PIE2 F80h PORTA

Note 1: This is not a physical register.

2: Unimplemented registers are read as ‘0’.

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 55
TABLE 5-2: REGISTER FILE SUMMARY (PIC18F1230/1330)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on 
POR, BOR
Details 
on 
Page:
TOSU — — — Top-of-Stack Upper Byte (TOS<20:16>) ---0 0000 41, 46
TOSH Top-of-Stack High Byte (TOS<15:8>) 0000 0000 41, 46
TOSL Top-of-Stack Low Byte (TOS<7:0>) 0000 0000 41, 46
STKPTR STKFUL(5) STKUNF(5) — SP4 SP3 SP2 SP1 SP0 00-0 0000 41, 47
PCLATU — — — Holding Register for PC<20:16> ---0 0000 41, 46
PCLATH Holding Register for PC<15:8> 0000 0000 41, 46
PCL PC Low Byte (PC<7:0>) 0000 0000 41, 46
TBLPTRU —— bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) --00 0000 41, 68
TBLPTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 41, 68
TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 0000 0000 41, 68
TABLAT Program Memory Table Latch 0000 0000 41, 68
PRODH Product Register High Byte xxxx xxxx 41, 79
PRODL Product Register Low Byte xxxx xxxx 41, 79
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 41, 89
INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP 1111 1111 41, 90
INTCON3 INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF 1100 0000 41, 91
INDF0 Uses contents of FSR0 to address data memory – value of FSR0 not changed (not a physical register) N/A 41, 60
POSTINC0 Uses contents of FSR0 to address data memory – value of FSR0 post-incremented (not a physical register) N/A 41, 60
POSTDEC0 Uses contents of FSR0 to address data memory – value of FSR0 post-decremented (not a physical register) N/A 41, 60
PREINC0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) N/A 41, 60
PLUSW0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) – 
value of FSR0 offset by W
N/A 41, 60
FSR0H — — — — Indirect Data Memory Address Pointer 0 High Byte ---- 0000 41, 60
FSR0L Indirect Data Memory Address Pointer 0 Low Byte xxxx xxxx 41, 60
WREG Working Register xxxx xxxx 41, 48
INDF1 Uses contents of FSR1 to address data memory – value of FSR1 not changed (not a physical register) N/A 41, 60
POSTINC1 Uses contents of FSR1 to address data memory – value of FSR1 post-incremented (not a physical register) N/A 41, 60
POSTDEC1 Uses contents of FSR1 to address data memory – value of FSR1 post-decremented (not a physical register) N/A 41, 60
PREINC1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) N/A 41, 60
PLUSW1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) – 
value of FSR1 offset by W
N/A 41, 60
FSR1H — — — — Indirect Data Memory Address Pointer 1 High Byte ---- 0000 41, 60
FSR1L Indirect Data Memory Address Pointer 1 Low Byte xxxx xxxx 41, 60
BSR — — — — Bank Select Register ---- 0000 41, 51
INDF2 Uses contents of FSR2 to address data memory – value of FSR2 not changed (not a physical register) N/A 42, 60
POSTINC2 Uses contents of FSR2 to address data memory – value of FSR2 post-incremented (not a physical register) N/A 42, 60
POSTDEC2 Uses contents of FSR2 to address data memory – value of FSR2 post-decremented (not a physical register) N/A 42, 60
PREINC2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) N/A 42, 60
PLUSW2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) – 
value of FSR2 offset by W
N/A 42, 60
FSR2H — — — — Indirect Data Memory Address Pointer 2 High Byte ---- 0000 42, 60
FSR2L Indirect Data Memory Address Pointer 2 Low Byte xxxx xxxx 42, 60
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition
Note 1: The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise, it is disabled and 
reads as ‘0’. See Section 4.4 “Brown-out Reset (BOR)”.
2: The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See 
Section 2.6.4 “PLL in INTOSC Modes”.
3: The RA5 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0); otherwise, RA5 reads 
as ‘0’. This bit is read-only.
4: RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary 
oscillator modes. When disabled, these bits read as ‘0’.
5: Bit 7 and bit 6 are cleared by user software or by a POR.
6: Reset condition of PWMEN bits depends on the PWMPIN Configuration bit of CONFIG3L.
7: This bit has no effect if the Configuration bit, WDTEN, is enabled.

PIC18F1230/1330
DS39758C-page 56 Advance Information © 2007 Microchip Technology Inc.
STATUS — — —NOVZ DC C---x xxxx 42, 58
TMR0H Timer0 Register High Byte 0000 0000 42, 103
TMR0L Timer0 Register Low Byte xxxx xxxx 42, 103
T0CON TMR0ON T016BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 42, 101
OSCCON IDLEN IRCF2 IRCF1 IRCF0 OSTS IOFS SCS1 SCS0 0100 q000 42, 22
LVDCON —— IRVST LVDEN LVDL3 LVDL2 LVDL1 LVDL0 --00 0101 42, 179
WDTCON — — — — — — —SWDTEN
(7) ---- ---0 42, 195
RCON IPEN SBOREN(1) —RITO PD POR BOR 0q-1 11q0 42, 34
TMR1H Timer1 Register High Byte xxxx xxxx 42, 109
TMR1L Timer1 Register Low Byte xxxx xxxx 42, 109
T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0000 0000 42, 105
ADRESH A/D Result Register High Byte xxxx xxxx 42, 172
ADRESL A/D Result Register Low Byte xxxx xxxx 42, 172
ADCON0 SEVTEN ——— CHS1 CHS0 GO/DONE ADON 0--- 0000 42, 163
ADCON1 — — — VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 ---0 1111 42, 164
ADCON2 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 0-00 0000 42, 165
BAUDCON ABDOVF RCIDL — SCKP BRG16 — WUE ABDEN 01-0 0-00 42, 144
CVRCON CVREN — CVRR CVRSS CVR3 CVR2 CVR1 CVR0 0-00 0000 42, 177
CMCON C2OUT C1OUT C0OUT —— CMEN2 CMEN1 CMEN0 000- -000 42, 173
SPBRGH EUSART Baud Rate Generator Register High Byte 0000 0000 42, 146
SPBRG EUSART Baud Rate Generator Register Low Byte 0000 0000 42, 146
RCREG EUSART Receive Register 0000 0000 42, 153
TXREG EUSART Transmit Register 0000 0000 42, 151
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 42, 142
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 42, 143
EEADR EEPROM Address Register 0000 0000 43, 75
EEDATA EEPROM Data Register 0000 0000 43, 75
EECON2 EEPROM Control Register 2 (not a physical register) 0000 0000 43, 66
EECON1 EEPGD CFGS — FREE WRERR WREN WR RD xx-0 x000 42, 67
IPR3 — — —PTIP— — — — ---1 ---- 43, 97
PIR3 — — —PTIF— — — — ---0 ---- 43, 93
PIE3 — — —PTIE— — — — ---0 ---- 43, 95
IPR2 OSCFIP —— EEIP —LVDIP — — 1--1 -1-- 43, 97
PIR2 OSCFIF ——EEIF—LVDIF — — 0--0 -0-- 43, 93
PIE2 OSCFIE —— EEIE —LVDIE — — 0--0 -0-- 43, 95
IPR1 — ADIP RCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP -111 1111 43, 96
PIR1 — ADIF RCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF -000 0000 43, 92
PIE1 — ADIE RCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE -000 0000 43, 94
OSCTUNE INTSRC PLLEN(2) — TUN4 TUN3 TUN2 TUN1 TUN0 00-0 0000 43, 19
PTCON0 PTOPS3 PTOPS2 PTOPS1 PTOPS0 PTCKPS1 PTCKPS0 PTMOD1 PTMOD0 0000 0000 43, 116
PTCON1 PTEN PTDIR — — — — — — 00-- ---- 43, 116
TABLE 5-2: REGISTER FILE SUMMARY (PIC18F1230/1330) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on 
POR, BOR
Details 
on 
Page:
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition
Note 1: The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise, it is disabled and 
reads as ‘0’. See Section 4.4 “Brown-out Reset (BOR)”.
2: The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See 
Section 2.6.4 “PLL in INTOSC Modes”.
3: The RA5 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0); otherwise, RA5 reads 
as ‘0’. This bit is read-only.
4: RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary 
oscillator modes. When disabled, these bits read as ‘0’.
5: Bit 7 and bit 6 are cleared by user software or by a POR.
6: Reset condition of PWMEN bits depends on the PWMPIN Configuration bit of CONFIG3L.
7: This bit has no effect if the Configuration bit, WDTEN, is enabled.

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 57
PTMRL PWM Time Base Register (lower 8 bits) 0000 0000 43, 119
PTMRH — — — — PWM Time Base Register (upper 4 bits) ---- 0000 43, 119
PTPERL PWM Time Base Period Register (lower 8 bits) 1111 1111 43, 119
PTPERH — — — — PWM Time Base Period Register (upper 4 bits) ---- 1111 43, 119
TRISB PORTB Data Direction Control Register 1111 1111 43, 84
TRISA TRISA7(4) TRISA6(4) PORTA Data Direction Control Register 1111 1111 43, 81
PDC0L PWM Duty Cycle #0L Register (lower 8 bits) 0000 0000 43, 125
PDC0H —— PWM Duty Cycle #0H Register (upper 6 bits) --00 0000 43, 125
PDC1L PWM Duty Cycle #1L Register (lower 8 bits) 0000 0000 43, 125
PDC1H —— PWM Duty Cycle #1H Register (upper 6 bits) --00 0000 43, 125
PDC2L PWM Duty Cycle #2L Register (lower 8 bits) 0000 0000 43, 125
PDC2H —— PWM Duty Cycle #2H Register (upper 6 bits) --00 0000 43, 125
FLTCONFIG BRFEN — — — — FLTAS FLTAMOD FLTAEN 0--- -000 43, 137
LATB PORTB Output Latch Register (Read and Write to Data Latch) xxxx xxxx 43, 84
LATA LATA7(4) LATA6(4) PORTA Output Latch Register (Read and Write to Data Latch) xxxx xxxx 43, 81
SEVTCMPL PWM Special Event Compare Register (lower 8 bits) 0000 0000 43, 138
SEVTCMPH — — — — PWM Special Event Compare Register (upper 4 bits) ---- 0000 44, 138
PWMCON0 —PWMEN2
(6) PWMEN1(6) PWMEN0(6) — PMOD2 PMOD1 PMOD0 -100 -000 44, 117
-000 -000
PWMCON1 SEVOPS3 SEVOPS2 SEVOPS1 SEVOPS0 SEVTDIR — UDIS OSYNC 0000 0-00 44, 118
DTCON DTPS1 DTPS0 DT5 DT4 DT3 DT2 DT1 DT0 0000 0000 44, 130
OVDCOND —— POVD5 POVD4 POVD3 POVD2 POVD1 POVD0 --11 1111 44, 134
OVDCONS —— POUT5 POUT4 POUT3 POUT2 POUT1 POUT0 --00 0000 44, 134
PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xxxx xxxx 44, 84
PORTA RA7(4) RA6(4) RA5(3) RA4 RA3 RA2 RA1 RA0 xx0x xxxx 44, 81
TABLE 5-2: REGISTER FILE SUMMARY (PIC18F1230/1330) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on 
POR, BOR
Details 
on 
Page:
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition
Note 1: The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise, it is disabled and 
reads as ‘0’. See Section 4.4 “Brown-out Reset (BOR)”.
2: The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See 
Section 2.6.4 “PLL in INTOSC Modes”.
3: The RA5 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0); otherwise, RA5 reads 
as ‘0’. This bit is read-only.
4: RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary 
oscillator modes. When disabled, these bits read as ‘0’.
5: Bit 7 and bit 6 are cleared by user software or by a POR.
6: Reset condition of PWMEN bits depends on the PWMPIN Configuration bit of CONFIG3L.
7: This bit has no effect if the Configuration bit, WDTEN, is enabled.

PIC18F1230/1330

5.3.5 STATUS REGISTER

The STATUS register, shown in Register 5-2, contains

the arithmetic status of the ALU. As with any other SFR,

it can be the operand for any instruction.

If the STATUS register is the destination for an instruc-

tion that affects the Z, DC, C, OV or N bits, the results

of the instruction are not written; instead, the STATUS

performed. Therefore, the result of an instruction with

the STATUS register as its destination may be different

than intended. As an example, CLRF STATUS will set

the Z bit and leave the remaining Status bits

unchanged (‘000u u1uu’).

It is recommended that only BCF, BSF, SWAPF, MOVFF

and MOVWF instructions are used to alter the STATUS

C, DC, OV or N bits in the STATUS register.

For other instructions that do not affect Status bits, see

the instruction set summaries in Table 21-2 and

Table 21-3.

Note: The C and DC bits operate as the borrow

and digit borrow bits, respectively, in

subtraction.

U-0 U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x

— — —NOVZDC

(1) C(2)

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-5 Unimplemented: Read as ‘0’

bit 4 N: Negative bit

This bit is used for signed arithmetic (2’s complement). It indicates whether the result was

negative (ALU MSB = 1).

1 = Result was negative

0 = Result was positive

bit 3 OV: Overflow bit

This bit is used for signed arithmetic (2’s complement). It indicates an overflow of the 7-bit

magnitude which causes the sign bit (bit 7 of the result) to change state.

1 = Overflow occurred for signed arithmetic (in this arithmetic operation)

0 = No overflow occurred

bit 2 Z: Zero bit

1 = The result of an arithmetic or logic operation is zero

0 = The result of an arithmetic or logic operation is not zero

bit 1 DC: Digit Carry/borrow bit(1)

For ADDWF, ADDLW, SUBLW and SUBWF instructions:

1 = A carry-out from the 4th low-order bit of the result occurred

0 = No carry-out from the 4th low-order bit of the result

bit 0 C: Carry/borrow bit(2)

For ADDWF, ADDLW, SUBLW and SUBWF instructions:

1 = A carry-out from the Most Significant bit of the result occurred

0 = No carry-out from the Most Significant bit of the result occurred

Note 1: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second

operand. For rotate (RRF, RLF) instructions, this bit is loaded with either bit 4 or bit 3 of the source register.

2: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second

operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low-order bit of the

source register.

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 59
5.4 Data Addressing Modes
The data memory space can be addressed in several
ways. For most instructions, the addressing mode is
fixed. Other instructions may use up to three modes,
depending on which operands are used and whether or
not the extended instruction set is enabled.
The addressing modes are:
• Inherent
• Literal
•Direct
•Indirect
An additional addressing mode, Indexed Literal Offset,
is available when the extended instruction set is
enabled (XINST Configuration bit = 1). Its operation is
discussed in greater detail in Section 5.5.1 “Indexed
Addressing with Literal Offset”. 
5.4.1 INHERENT AND LITERAL 
ADDRESSING
Many PIC18 control instructions do not need any
argument at all; they either perform an operation that
globally affects the device or they operate implicitly on
one register. This addressing mode is known as Inherent
Addressing. Examples include SLEEP, RESET and DAW.
Other instructions work in a similar way but require an
additional explicit argument in the opcode. This is
known as Literal Addressing mode because they
require some literal value as an argument. Examples
include ADDLW and MOVLW, which respectively, add or
move a literal value to the W register. Other examples
include  CALL and GOTO, which include a 20-bit
program memory address.
5.4.2 DIRECT ADDRESSING
Direct Addressing specifies all or part of the source
and/or destination address of the operation within the
opcode itself. The options are specified by the
arguments accompanying the instruction.
In the core PIC18 instruction set, bit-oriented and byte-
oriented instructions use some version of Direct
Addressing by default. All of these instructions include
some 8-bit literal address as their Least Significant
Byte. This address specifies either a register address in
one of the banks of data RAM (Section 5.3.3 “General
Purpose Register File”) or a location in the Access
Bank (Section 5.3.2 “Access Bank”) as the data
source for the instruction. 
The Access RAM bit ‘a’ determines how the address is
interpreted. When ‘a’ is ‘1’, the contents of the BSR
(Section 5.3.1 “Bank Select Register (BSR)”) are
used with the address to determine the complete 12-bit
address of the register. When ‘a’ is ‘0’, the address is
interpreted as being a register in the Access Bank.
Addressing that uses the Access RAM is sometimes
also known as Direct Forced Addressing mode.
A few instructions, such as MOVFF, include the entire
12-bit address (either source or destination) in their
opcodes. In these cases, the BSR is ignored entirely.
The destination of the operation’s results is determined
by the destination bit ‘d’. When ‘d’ is ‘1’, the results are
stored back in the source register, overwriting its
original contents. When ‘d’ is ‘0’, the results are stored
in the W register. Instructions without the ‘d’ argument
have a destination that is implicit in the instruction; their
destination is either the target register being operated
on or the W register.
5.4.3 INDIRECT ADDRESSING
Indirect Addressing allows the user to access a location
in data memory without giving a fixed address in the
instruction. This is done by using File Select Registers
(FSRs) as pointers to the locations to be read or written
to. Since the FSRs are themselves located in RAM as
Special Function Registers, they can also be directly
manipulated under program control. This makes FSRs
very useful in implementing data structures, such as
tables and arrays in data memory. 
The registers for Indirect Addressing are also
implemented with Indirect File Operands (INDFs) that
permit automatic manipulation of the pointer value with
auto-incrementing, auto-decrementing or offsetting
with another value. This allows for efficient code, using
loops, such as the example of clearing an entire RAM
bank in Example 5-5.
EXAMPLE 5-5: HOW TO CLEAR RAM 
(BANK 0) USING 
INDIRECT ADDRESSING   
Note: The execution of some instructions in the
core PIC18 instruction set are changed
when the PIC18 extended instruction set is
enabled. See Section 5.5 “Data Memory
and the Extended Instruction Set” for
more information.
LFSR FSR0, 00h ;   
NEXT  CLRF POSTINC0 ; Clear INDF 
; register then 
; inc pointer 
BTFSS FSR0H, 0 ; All done with
; Bank0? 
BRA NEXT ; NO, clear next 
CONTINUE ; YES, continue 

PIC18F1230/1330

5.4.3.1 FSR Registers and the

INDF Operand

At the core of Indirect Addressing are three sets of

registers: FSR0, FSR1 and FSR2. Each represents a

pair of 8-bit registers, FSRnH and FSRnL. The four

upper bits of the FSRnH register are not used so each

FSR pair holds a 12-bit value. This represents a value

that can address the entire range of the data memory

in a linear fashion. The FSR register pairs, then, serve

as pointers to data memory locations.

Indirect Addressing is accomplished with a set of

Indirect File Operands, INDF0 through INDF2. These

can be thought of as “virtual” registers: they are

mapped in the SFR space but are not physically

implemented. Reading or writing to a particular INDF

the data at the address indicated by FSR1H:FSR1L.

Instructions that use the INDF registers as operands

actually use the contents of their corresponding FSR as

a pointer to the instruction’s target. The INDF operand

is just a convenient way of using the pointer.

Because Indirect Addressing uses a full 12-bit address,

data RAM banking is not necessary. Thus, the current

contents of the BSR and the Access RAM bit have no

effect on determining the target address.

5.4.3.2 FSR Registers and POSTINC,

POSTDEC, PREINC and PLUSW

In addition to the INDF operand, each FSR register pair

also has four additional indirect operands. Like INDF,

these are “virtual” registers that cannot be indirectly

read or written to. Accessing these registers actually

accesses the associated FSR register pair, but also

performs a specific action on its stored value. They are:

• POSTDEC: accesses the FSR value, then

automatically decrements it by 1 afterwards

• POSTINC: accesses the FSR value, then

automatically increments it by 1 afterwards

• PREINC: increments the FSR value by 1, then

uses it in the operation

• PLUSW: adds the signed value of the W register

(range of -127 to 128) to that of the FSR and uses

the new value in the operation.

In this context, accessing an INDF register uses the

value in the FSR registers without changing them. Sim-

ilarly, accessing a PLUSW register gives the FSR value

offset by that in the W register; neither value is actually

changed in the operation. Accessing the other virtual

registers changes the value of the FSR registers.

Operations on the FSRs with POSTDEC, POSTINC

and PREINC affect the entire register pair; that is, roll-

overs of the FSRnL register from FFh to 00h carry over

to the FSRnH register. On the other hand, results of

these operations do not change the value of any flags

in the STATUS register (e.g., Z, N, OV, etc.).

FIGURE 5-7: INDIRECT ADDRESSING

FSR1H:FSR1L

Data Memory

000h

100h

200h

300h

F00h

E00h

FFFh

Bank 0

Bank 1

Bank 2

Bank 14

Bank 15

Bank 3

through

Bank 13

ADDWF, INDF1, 1

Using an instruction with one of the

indirect addressing registers as the

operand....

...uses the 12-bit address stored in

the FSR pair associated with that

...to determine the data memory

location to be used in that operation.

In this case, the FSR1 pair contains

ECCh. This means the contents of

location ECCh will be added to that

of the W register and stored back in

ECCh.

xxxx1110 11001100

PIC18F1230/1330

The PLUSW register can be used to implement a form

of Indexed Addressing in the data memory space. By

manipulating the value in the W register, users can

reach addresses that are fixed offsets from pointer

addresses. In some applications, this can be used to

implement some powerful program control structure,

such as software stacks, inside of data memory.

5.4.3.3 Operations by FSRs on FSRs

Indirect Addressing operations that target other FSRs

or virtual registers represent special cases. For

example, using an FSR to point to one of the virtual

registers will not result in successful operations. As a

specific case, assume that FSR0H:FSR0L contains

FE7h, the address of INDF1. Attempts to read the

value of the INDF1 using INDF0 as an operand will

return 00h. Attempts to write to INDF1 using INDF0 as

the operand will result in a NOP.

On the other hand, using the virtual registers to write to

an FSR pair may not occur as planned. In these cases,

the value will be written to the FSR pair but without any

incrementing or decrementing. Thus, writing to INDF2

or POSTDEC2 will write the same value to the

FSR2H:FSR2L.

Since the FSRs are physical registers mapped in the

SFR space, they can be manipulated through all direct

operations. Users should proceed cautiously when

working on these registers, particularly if their code

uses Indirect Addressing.

Similarly, operations by Indirect Addressing are gener-

ally permitted on all other SFRs. Users should exercise

the appropriate caution that they do not inadvertently

change settings that might affect the operation of the

device.

5.5 Data Memory and the Extended

Instruction Set

Enabling the PIC18 extended instruction set (XINST

Configuration bit = 1) significantly changes certain

aspects of data memory and its addressing. Specifically,

the use of the Access Bank for many of the core PIC18

instructions is different; this is due to the introduction of

a new addressing mode for the data memory space.

What does not change is just as important. The size of

the data memory space is unchanged, as well as its

linear addressing. The SFR map remains the same.

Core PIC18 instructions can still operate in both Direct

and Indirect Addressing mode; inherent and literal

instructions do not change at all. Indirect Addressing

with FSR0 and FSR1 also remains unchanged.

5.5.1 INDEXED ADDRESSING WITH

LITERAL OFFSET

Enabling the PIC18 extended instruction set changes

the behavior of Indirect Addressing using the FSR2

conditions, instructions that use the Access Bank – that

is, most bit-oriented and byte-oriented instructions – can

invoke a form of Indexed Addressing using an offset

specified in the instruction. This special addressing

mode is known as Indexed Addressing with Literal

Offset, or Indexed Literal Offset mode.

When using the extended instruction set, this

addressing mode requires the following:

• The use of the Access Bank is forced (‘a’ = 0);

and

• The file address argument is less than or equal to

5Fh.

Under these conditions, the file address of the

instruction is not interpreted as the lower byte of an

address (used with the BSR in Direct Addressing), or

as an 8-bit address in the Access Bank. Instead, the

value is interpreted as an offset value to an Address

Pointer, specified by FSR2. The offset and the contents

of FSR2 are added to obtain the target address of the

operation.

5.5.2 INSTRUCTIONS AFFECTED BY

INDEXED LITERAL OFFSET MODE

Any of the core PIC18 instructions that can use Direct

Addressing are potentially affected by the Indexed

Literal Offset Addressing mode. This includes all

byte-oriented and bit-oriented instructions, or almost

one-half of the standard PIC18 instruction set.

Instructions that only use Inherent or Literal Addressing

modes are unaffected.

Additionally, byte-oriented and bit-oriented instructions

are not affected if they do not use the Access Bank

(Access RAM bit is ‘1’), or include a file address of 60h

or above. Instructions meeting these criteria will

continue to execute as before. A comparison of the

different possible addressing modes when the

extended instruction set is enabled is shown in

Figure 5-8.

Those who desire to use bit-oriented or byte-oriented

instructions in the Indexed Literal Offset mode should

note the changes to assembler syntax for this mode.

This is described in more detail in Section 21.2.1

“Extended Instruction Syntax”.

PIC18F1230/1330

FIGURE 5-8: COMPARING ADDRESSING OPTIONS FOR BIT-ORIENTED AND

BYTE-ORIENTED INSTRUCTIONS (EXTENDED INSTRUCTION SET ENABLED)

EXAMPLE INSTRUCTION: ADDWF, f, d, a (Opcode: 0010 01da ffff ffff)

When ‘a’ = 0 and f ≥ 60h:

The instruction executes in

Direct Forced mode. ‘f’ is

interpreted as a location in the

Access RAM between 060h

and 0FFh. This is the same as

locations 060h to 07Fh

(Bank 0) and F80h to FFFh

(Bank 15) of data memory.

Locations below 60h are not

available in this addressing

mode.

When ‘a’ = 0 and f ≤ 5Fh:

The instruction executes in

Indexed Literal Offset mode. ‘f’

is interpreted as an offset to the

address value in FSR2. The

two are added together to

obtain the address of the target

address can be anywhere in

the data memory space.

Note that in this mode, the

correct syntax is now:

ADDWF [k], d

where ‘k’ is the same as ‘f’.

When ‘a’ = 1 (all values of f):

The instruction executes in

Direct mode (also known as

Direct Long mode). ‘f’ is

interpreted as a location in

one of the 16 banks of the data

memory space. The bank is

designated by the Bank Select

can be in any implemented

bank in the data memory

space.

000h

060h

100h

F00h

F80h

FFFh

Valid range

00h

60h

80h

FFh

Data Memory

Access RAM

Bank 0

Bank 1

through

Bank 14

Bank 15

SFRs

000h

080h

100h

F00h

F80h

FFFh

Data Memory

Bank 0

Bank 1

through

Bank 14

Bank 15

SFRs

FSR2H FSR2L

ffffffff001001da

000h

080h

100h

F00h

F80h

FFFh

Data Memory

Bank 0

Bank 1

through

Bank 14

Bank 15

SFRs

for ‘f’

BSR

00000000

080h

PIC18F1230/1330

5.5.3 MAPPING THE ACCESS BANK IN

INDEXED LITERAL OFFSET

ADDRESSING MODE

The use of Indexed Literal Offset Addressing mode

effectively changes how the first 96 locations of Access

RAM (00h to 5Fh) are mapped. Rather than containing

just the contents of the bottom half of Bank 0, this mode

maps the contents from Bank 0 and a user-defined

“window” that can be located anywhere in the data

memory space. The value of FSR2 establishes the

lower boundary of the addresses mapped into the

window, while the upper boundary is defined by FSR2

plus 95 (5Fh). Addresses in the Access RAM above

5Fh are mapped as previously described (see

Section 5.3.2 “Access Bank”). An example of Access

Bank remapping in this addressing mode is shown in

Figure 5-9.

Remapping of the Access Bank applies

only

operations using the Indexed Literal Offset Addressing

mode. Operations that use the BSR (Access RAM bit is

‘1’) will continue to use Direct Addressing as before.

5.6 PIC18 Instruction Execution and

the Extended Instruction Set

Enabling the extended instruction set adds eight

additional commands to the existing PIC18 instruction

set. These instructions are executed as described in

Section 21.2 “Extended Instruction Set”.

FIGURE 5-9: REMAPPING THE ACCESS BANK WITH INDEXED LITERAL OFFSET

ADDRESSING MODE

Data Memory

000h

100h

F80h

F00h

FFFh

Bank 0

Bank 15

Bank 1

through

Bank 14

SFRs

05Fh

ADDWF f, d, a

FSR2H:FSR2L = 090h

Locations in the region

from the FSR2 Pointer

(090h) to the pointer plus

05Fh (0EFh) are mapped

to the bottom of the

Access RAM (000h-05Fh).

Locations in Bank 0 from

060h to 07Fh are mapped,

as usual, to the middle of

the Access Bank.

Special Function Regis-

ters at F80h through FFFh

are mapped to 80h

through FFh, as usual.

Bank 0 addresses below

5Fh can still be addressed

by using the BSR.

Access Bank

00h

80h

FFh

7Fh

SFRs

Bank 0 “Window”

Bank 0

Window

Example Situation:

07Fh

090h

0EFh

5Fh

PIC18F1230/1330

NOTES:

PIC18F1230/1330

6.0 FLASH PROGRAM MEMORY

The Flash program memory is readable, writable and

erasable during normal operation over the entire VDD

range.

A read from program memory is executed on one byte

at a time. A write to program memory is executed on

blocks of 8 bytes at a time. Program memory is erased

in blocks of 64 bytes at a time. A bulk erase operation

may not be issued from user code.

Writing or erasing program memory will cease

instruction fetches until the operation is complete. The

program memory cannot be accessed during the write

or erase, therefore, code cannot execute. An internal

programming timer terminates program memory writes

and erases.

A value written to program memory does not need to be

a valid instruction. Executing a program memory

location that forms an invalid instruction results in a

NOP.

6.1 Table Reads and Table Writes

In order to read and write program memory, there are

two operations that allow the processor to move bytes

between the program memory space and the data RAM:

• Table Read (TBLRD)

• Table Write (TBLWT)

The program memory space is 16 bits wide, while the

data RAM space is 8 bits wide. Table reads and table

writes move data between these two memory spaces

through an 8-bit register (TABLAT).

Table read operations retrieve data from program

memory and place it into the data RAM space.

Figure 6-1 shows the operation of a table read with

program memory and data RAM.

Table write operations store data from the data memory

space into holding registers in program memory. The

procedure to write the contents of the holding registers

into program memory is detailed in Section 6.5 “Writing

to Flash Program Memory”. Figure 6-2 shows the

operation of a table write with program memory and data

RAM.

Table operations work with byte entities. A table block

containing data, rather than program instructions, is not

required to be word-aligned. Therefore, a table block can

start and end at any byte address. If a table write is being

used to write executable code into program memory,

program instructions will need to be word-aligned.

FIGURE 6-1: TABLE READ OPERATION

Table Pointer(1)

Table Latch (8-bit)

Program Memory

TBLPTRH TBLPTRL

TABLAT

TBLPTRU

Instruction: TBLRD*

Note 1: Table Pointer register points to a byte in program memory.

Program Memory

(TBLPTR)

PIC18F1230/1330

FIGURE 6-2: TABLE WRITE OPERATION

6.2 Control Registers

Several control registers are used in conjunction with

the TBLRD and TBLWT instructions. These include the:

• EECON1 register

• EECON2 register

• TABLAT register

• TBLPTR registers

6.2.1 EECON1 AND EECON2 REGISTERS

The EECON1 register (Register 6-1) is the control

not a physical register; it is used exclusively in the

memory write and erase sequences. Reading

EECON2 will read all ‘0’s.

The EEPGD control bit determines if the access will be

a program or data EEPROM memory access. When

clear, any subsequent operations will operate on the

data EEPROM memory. When set, any subsequent

operations will operate on the program memory.

The CFGS control bit determines if the access will be

to the Configuration/Calibration registers or to program

memory/data EEPROM memory. When set,

subsequent operations will operate on Configuration

registers regardless of EEPGD (see Section 19.0

“Special Features of the CPU”). When clear, memory

selection access is determined by EEPGD.

The FREE bit, when set, will allow a program memory

erase operation. When FREE is set, the erase

operation is initiated on the next WR command. When

FREE is clear, only writes are enabled.

The WREN bit, when set, will allow a write operation.

On power-up, the WREN bit is clear. The WRERR bit is

set in hardware when the WR bit is set and cleared

when the internal programming timer expires and the

write operation is complete.

The WR control bit initiates write operations. The bit

cannot be cleared, only set, in software; it is cleared in

hardware at the completion of the write operation.

Table Pointer(1) Table Latch (8-bit)

TBLPTRH TBLPTRL TABLAT

Program Memory

(TBLPTR)

TBLPTRU

Instruction: TBLWT*

Note 1: Table Pointer actually points to one of 8 holding registers, the address of which is determined by

TBLPTRL<5:0>. The process for physically writing data to the program memory array is discussed in

Section 6.5 “Writing to Flash Program Memory”.

Holding Registers

Program Memory

Note: During normal operation, the WRERR

may read as ‘1’. This can indicate that a

write operation was prematurely termi-

nated by a Reset, or a write operation was

attempted improperly.

Note: The EEIF interrupt flag bit (PIR2<4>) is set

when the write is complete. It must be

cleared in software.

PIC18F1230/1330

R/W-x R/W-x U-0 R/W-0 R/W-x R/W-0 R/S-0 R/S-0

EEPGD CFGS — FREE WRERR(1) WREN WR RD

bit 7 bit 0

Legend: S = Settable bit

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 EEPGD: Flash Program or Data EEPROM Memory Select bit

1 = Access Flash program memory

0 = Access data EEPROM memory

bit 6 CFGS: Flash Program/Data EEPROM or Configuration Select bit

1 = Access Configuration registers

0 = Access Flash program or data EEPROM memory

bit 5 Unimplemented: Read as ‘0’

bit 4 FREE: Flash Row Erase Enable bit

1 = Erase the program memory row addressed by TBLPTR on the next WR command

(cleared by completion of erase operation)

0 = Perform write-only

bit 3 WRERR: Flash Program/Data EEPROM Error Flag bit(1)

1 = A write operation is prematurely terminated (any Reset during self-timed programming in normal

operation, or an improper write attempt)

0 = The write operation completed

bit 2 WREN: Flash Program/Data EEPROM Write Enable bit

1 = Allows write cycles to Flash program/data EEPROM

0 = Inhibits write cycles to Flash program/data EEPROM

bit 1 WR: Write Control bit

1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle.

(The operation is self-timed and the bit is cleared by hardware once write is complete.

The WR bit can only be set (not cleared) in software.)

0 = Write cycle to the EEPROM is complete

bit 0 RD: Read Control bit

1 = Initiates an EEPROM read. (Read takes one cycle. RD is cleared in hardware. The RD bit can only

be set (not cleared) in software. RD bit cannot be set when EEPGD = 1 or CFGS = 1.)

0 = Does not initiate an EEPROM read

Note 1: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows tracing of the error

condition.

PIC18F1230/1330

6.2.2 TABLAT – TABLE LATCH REGISTER

The Table Latch (TABLAT) is an 8-bit register mapped

into the SFR space. The Table Latch register is used to

hold 8-bit data during data transfers between program

memory and data RAM.

6.2.3 TBLPTR – TABLE POINTER

The Table Pointer (TBLPTR) register addresses a byte

within the program memory. The TBLPTR is comprised

of three SFR registers: Table Pointer Upper Byte,

Table Pointer High Byte and Table Pointer Low Byte

(TBLPTRU:TBLPTRH:TBLPTRL). These three

registers join to form a 22-bit wide pointer. The low-

order 21 bits allow the device to address up to

2 Mbytes of program memory space. The 22nd bit

allows access to the device ID, the user ID and the

Configuration bits.

The Table Pointer register, TBLPTR, is used by the

TBLRD and TBLWT instructions. These instructions can

update the TBLPTR in one of four ways based on the

table operation. These operations are shown in

Table 6-1. These operations on the TBLPTR only affect

the low-order 21 bits.

6.2.4 TABLE POINTER BOUNDARIES

TBLPTR is used in reads, writes and erases of the

Flash program memory.

When a TBLRD is executed, all 22 bits of the TBLPTR

determine which byte is read from program memory

into TABLAT.

When a TBLWT is executed, the three LSbs of the Table

Pointer register (TBLPTR<2:0>) determine which of

the 8 program memory holding registers is written to.

When the timed write to program memory begins (via

the WR bit), the 19 MSbs of the TBLPTR

(TBLPTR<21:3>) determine which program memory

block of 8 bytes is written to. For more detail, see

Section 6.5 “Writing to Flash Program Memory”.

When an erase of program memory is executed, the

16 MSbs of the Table Pointer register

(TBLPTR<21:6>) point to the 64-byte block that will be

erased. The Least Significant bits (TBLPTR<5:0>) are

ignored.

Figure 6-3 describes the relevant boundaries of

TBLPTR based on Flash program memory operations.

TABLE 6-1: TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS

FIGURE 6-3: TABLE POINTER BOUNDARIES BASED ON OPERATION

Example Operation on Table Pointer

TBLRD*

TBLWT* TBLPTR is not modified

TBLRD*+

TBLWT*+ TBLPTR is incremented after the read/write

TBLRD*-

TBLWT*- TBLPTR is decremented after the read/write

TBLRD+*

TBLWT+* TBLPTR is incremented before the read/write

21 16 15 87 0

TABLE ERASE/WRITE TABLE WRITE

TABLE READ – TBLPTR<21:0>

TBLPTRLTBLPTRH

TBLPTRU

TBLPTR<5:0>TBLPTR<21:6>

PIC18F1230/1330

6.3 Reading the Flash Program

Memory

The TBLRD instruction is used to retrieve data from

program memory and places it into data RAM. Table

reads from program memory are performed one byte at

a time.

TBLPTR points to a byte address in program space.

Executing TBLRD places the byte pointed to into

TABLAT. In addition, TBLPTR can be modified

automatically for the next table read operation.

The internal program memory is typically organized by

words. The Least Significant bit of the address selects

between the high and low bytes of the word. Figure 6-4

shows the interface between the internal program

memory and the TABLAT.

FIGURE 6-4: READS FROM FLASH PROGRAM MEMORY

EXAMPLE 6-1: READING A FLASH PROGRAM MEMORY WORD

(Even Byte Address)

Program Memory

(Odd Byte Address)

TBLRD TABLAT

TBLPTR = xxxxx1

FETCH

Instruction Register

(IR) Read Register

TBLPTR = xxxxx0

MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base

MOVWF TBLPTRU ; address of the word

MOVLW CODE_ADDR_HIGH

MOVWF TBLPTRH

MOVLW CODE_ADDR_LOW

MOVWF TBLPTRL

READ_WORD

TBLRD*+ ; read into TABLAT and increment

MOVF TABLAT, W ; get data

MOVWF WORD_EVEN

TBLRD*+ ; read into TABLAT and increment

MOVF TABLAT, W ; get data

MOVWF WORD_ODD

PIC18F1230/1330

6.4 Erasing Flash Program Memory

The minimum erase block is 32 words or 64 bytes. Only

through the use of an external programmer, or through

ICSP control, can larger blocks of program memory be

bulk erased. Word erase in the Flash array is not

supported.

When initiating an erase sequence from the micro-

controller itself, a block of 64 bytes of program memory

is erased. The Most Significant 16 bits of the

TBLPTR<21:6> point to the block being erased.

TBLPTR<5:0> are ignored.

The EECON1 register commands the erase operation.

The EEPGD bit must be set to point to the Flash

program memory. The WREN bit must be set to enable

write operations. The FREE bit is set to select an erase

operation.

For protection, the write initiate sequence for EECON2

must be used.

A long write is necessary for erasing the internal Flash.

Instruction execution is halted while in a long write

cycle. The long write will be terminated by the internal

programming timer.

6.4.1 FLASH PROGRAM MEMORY

ERASE SEQUENCE

The sequence of events for erasing a block of internal

program memory location is:

1. Load Table Pointer register with address of row

being erased.

2. Set the EECON1 register for the erase operation:

• set EEPGD bit to point to program memory;

• clear the CFGS bit to access program memory;

• set WREN bit to enable writes;

• set FREE bit to enable the erase.

3. Disable interrupts.

4. Write 55h to EECON2.

5. Write 0AAh to EECON2.

6. Set the WR bit. This will begin the row erase

cycle.

7. The CPU will stall for duration of the erase

(about 2 ms using internal timer).

8. Re-enable interrupts.

EXAMPLE 6-2: ERASING A FLASH PROGRAM MEMORY ROW

MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base

MOVWF TBLPTRU ; address of the memory block

MOVLW CODE_ADDR_HIGH

MOVWF TBLPTRH

MOVLW CODE_ADDR_LOW

MOVWF TBLPTRL

ERASE_ROW

BSF EECON1, EEPGD ; point to Flash program memory

BCF EECON1, CFGS ; access Flash program memory

BSF EECON1, WREN ; enable write to memory

BSF EECON1, FREE ; enable Row Erase operation

BCF INTCON, GIE ; disable interrupts

Required MOVLW 55h

Sequence MOVWF EECON2 ; write 55h

MOVLW 0AAh

MOVWF EECON2 ; write 0AAh

BSF EECON1, WR ; start erase (CPU stall)

BSF INTCON, GIE ; re-enable interrupts

PIC18F1230/1330

6.5 Writing to Flash Program Memory

The minimum programming block is 4 words or 8 bytes.

Word or byte programming is not supported.

Table writes are used internally to load the holding

registers needed to program the Flash memory. There

are 8 holding registers used by the table writes for

programming.

Since the Table Latch (TABLAT) is only a single byte,

the TBLWT instruction may need to be executed 8 times

for each programming operation. All of the table write

operations will essentially be short writes because only

the holding registers are written. At the end of updating

the 8 holding registers, the EECON1 register must be

written to in order to start the programming operation with

a long write.

The long write is necessary for programming the

internal Flash. Instruction execution is halted while in a

long write cycle. The long write will be terminated by

the internal programming timer.

The EEPROM on-chip timer controls the write time.

The write/erase voltages are generated by an on-chip

charge pump, rated to operate over the voltage range

of the device.

FIGURE 6-5: TABLE WRITES TO FLASH PROGRAM MEMORY

6.5.1 FLASH PROGRAM MEMORY

WRITE SEQUENCE

The sequence of events for programming an internal

program memory location should be:

1. Read 8 bytes into RAM.

2. Update data values in RAM as necessary.

3. Load Table Pointer register with address being

erased.

4. Execute the row erase procedure.

5. Load Table Pointer register with address of first

byte being written.

6. Write the 8 bytes into the holding registers with

auto-increment.

7. Set the EECON1 register for the write operation:

• set EEPGD bit to point to program memory;

• clear the CFGS bit to access program memory;

• set WREN to enable byte writes.

8. Disable interrupts.

9. Write 55h to EECON2.

10. Write 0AAh to EECON2.

11. Set the WR bit. This will begin the write cycle.

12. The CPU will stall for duration of the write (about

2 ms using internal timer).

13. Re-enable interrupts.

14. Verify the memory (table read).

This procedure will require about 6 ms to update one

row of 8 bytes of memory. An example of the required

code is given in Example 6-3.

Note: The default value of the holding registers on

device Resets and after write operations is

FFh. A write of FFh to a holding register

does not modify that byte. This means that

individual bytes of program memory may be

modified, provided that the change does not

attempt to change any bit from a ‘0’ to a ‘1’.

When modifying individual bytes, it is not

necessary to load all 8 holding registers

before executing a write operation.

TABLAT

TBLPTR = xxxxx7TBLPTR = xxxxx1TBLPTR = xxxxx0

Write Register

TBLPTR = xxxxx2

Program Memory

Holding Register Holding Register Holding Register Holding Register

88 8 8

Note: Before setting the WR bit, the Table

Pointer address needs to be within the

intended address range of the 8 bytes in

the holding register.

PIC18F1230/1330

EXAMPLE 6-3: WRITING TO FLASH PROGRAM MEMORY

MOVLW D'8 ; number of bytes in erase block

MOVWF COUNTER

MOVLW BUFFER_ADDR_HIGH ; point to buffer

MOVWF FSR0H

MOVLW BUFFER_ADDR_LOW

MOVWF FSR0L

MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base

MOVWF TBLPTRU ; address of the memory block

MOVLW CODE_ADDR_HIGH

MOVWF TBLPTRH

MOVLW CODE_ADDR_LOW

MOVWF TBLPTRL

READ_BLOCK

TBLRD*+ ; read into TABLAT, and inc

MOVF TABLAT, W ; get data

MOVWF POSTINC0 ; store data

DECFSZ COUNTER ; done?

BRA READ_BLOCK ; repeat

MODIFY_WORD

MOVLW DATA_ADDR_HIGH ; point to buffer

MOVWF FSR0H

MOVLW DATA_ADDR_LOW

MOVWF FSR0L

MOVLW NEW_DATA_LOW ; update buffer word

MOVWF POSTINC0

MOVLW NEW_DATA_HIGH

MOVWF INDF0

ERASE_BLOCK

MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base

MOVWF TBLPTRU ; address of the memory block

MOVLW CODE_ADDR_HIGH

MOVWF TBLPTRH

MOVLW CODE_ADDR_LOW

MOVWF TBLPTRL

BSF EECON1, EEPGD ; point to Flash program memory

BCF EECON1, CFGS ; access Flash program memory

BSF EECON1, WREN ; enable write to memory

BSF EECON1, FREE ; enable Row Erase operation

BCF INTCON, GIE ; disable interrupts

MOVLW 55h

Required MOVWF EECON2 ; write 55h

Sequence MOVLW 0AAh

MOVWF EECON2 ; write 0AAh

BSF EECON1, WR ; start erase (CPU stall)

BSF INTCON, GIE ; re-enable interrupts

TBLRD*- ; dummy read decrement

MOVLW BUFFER_ADDR_HIGH ; point to buffer

MOVWF FSR0H

MOVLW BUFFER_ADDR_LOW

MOVWF FSR0L

WRITE_BUFFER_BACK

MOVLW D’8 ; number of bytes in holding register

MOVWF COUNTER

WRITE_BYTE_TO_HREGS

MOVFF POSTINC0, WREG ; get low byte of buffer data

MOVWF TABLAT ; present data to table latch

TBLWT+* ; write data, perform a short write

; to internal TBLWT holding register.

DECFSZ COUNTER ; loop until buffers are full

BRA WRITE_WORD_TO_HREGS

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 73
EXAMPLE 6-3: WRITING TO FLASH PROGRAM MEMORY (CONTINUED)
6.5.2 WRITE VERIFY
Depending on the application, good programming
practice may dictate that the value written to the
memory should be verified against the original value.
This should be used in applications where excessive
writes can stress bits near the specification limit.
6.5.3 UNEXPECTED TERMINATION OF 
WRITE OPERATION
If a write is terminated by an unplanned event, such as
loss of power or an unexpected Reset, the memory
location just programmed should be verified and
reprogrammed, if needed. If the write operation is
interrupted by a MCLR Reset or a WDT Time-out Reset
during normal operation, the user can check the
WRERR bit and rewrite the location(s) as needed.
6.5.4 PROTECTION AGAINST 
SPURIOUS WRITES
To protect against spurious writes to Flash program
memory, the write initiate sequence must also be
followed. See Section 19.0 “Special Features of the
CPU” for more detail.
6.6 Flash Program Operation During 
Code Protection
See  Section 19.5 “Program Verification and Code
Protection” for details on code protection of Flash
program memory.
TABLE 6-2: REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY 
PROGRAM_MEMORY
BSF EECON1, EEPGD ; point to Flash program memory
BCF EECON1, CFGS ; access Flash program memory
BSF EECON1, WREN ; enable write to memory
BCF INTCON, GIE ; disable interrupts
MOVLW 55h
Required MOVWF EECON2 ; write 55h
Sequence MOVLW 0AAh
MOVWF EECON2  ; write 0AAh
BSF EECON1, WR ; start program (CPU stall)
BSF INTCON, GIE ; re-enable interrupts
BCF EECON1, WREN ; disable write to memory
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values on 
Page:
TBLPTRU —— bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) 41
TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 41
TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 41
TABLAT Program Memory Table Latch 41
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
EECON2 EEPROM Control Register 2 (not a physical register) 43
EECON1 EEPGD CFGS — FREE WRERR WREN WR RD 43
IPR2 OSCFIP ——EEIP —LVDIP ——43
PIR2 OSCFIF ——EEIF —LVDIF ——43
PIE2 OSCFIE ——EEIE —LVDIE ——43
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.

PIC18F1230/1330

NOTES:

PIC18F1230/1330

7.0 DATA EEPROM MEMORY

The data EEPROM is readable and writable during

normal operation over the entire VDD range. The data

memory is not directly mapped in the register file

space. Instead, it is indirectly addressed through the

Special Function Registers (SFR).

There are four SFRs used to read and write the

program and data EEPROM memory. These registers

are:

• EECON1

• EECON2

• EEDATA

• EEADR

The EEPROM data memory allows byte read and write.

When interfacing to the data memory block, EEDATA

holds the 8-bit data for read/write and EEADR holds the

address of the EEPROM location being accessed.

These devices have 128 bytes of data EEPROM with

an address range from 00h to FFh.

The EEPROM data memory is rated for high erase/

write cycle endurance. A byte write automatically

erases the location and writes the new data (erase-

before-write). The write time is controlled by an on-chip

timer. The write time will vary with voltage and

temperature, as well as from chip-to-chip. Please

refer to parameter D122 (Table 22-1 in Section 22.0

“Electrical Characteristics”) for exact limits.

7.1 EEADR Register

The EEPROM Address register can address 256 bytes

of data EEPROM.

7.2 EECON1 and EECON2 Registers

EECON1 is the control register for memory accesses.

EECON2 is not a physical register. Reading EECON2

will read all ‘0’s. The EECON2 register is used

exclusively in the memory write and erase sequences.

Control bit, EEPGD, determines if the access will be to

program or data EEPROM memory. When clear,

operations will access the data EEPROM memory.

When set, program memory is accessed.

Control bit, CFGS, determines if the access will be to

the Configuration registers or to program memory/data

EEPROM memory. When set, subsequent operations

access Configuration registers. When CFGS is clear,

the EEPGD bit selects either program Flash or data

EEPROM memory.

The WREN bit enables and disables erase and write

operations. When set, erase and write operations are

allowed. When clear, erase and write operations are

disabled; the WR bit cannot be set while the WREN bit

is clear. This mechanism helps to prevent accidental

writes to memory due to errant (unexpected) code

execution.

Firmware should keep the WREN bit clear at all times,

except when starting erase or write operations. Once

firmware has set the WR bit, the WREN bit may be

cleared. Clearing the WREN bit will not affect the

operation in progress.

The WRERR bit is set when a write operation is

interrupted by a Reset. In these situations, the user can

check the WRERR bit and rewrite the location. It is

necessary to reload the data and address registers

(EEDATA and EEADR), as these registers have

cleared as a result of the Reset.

Control bits, RD and WR, start read and erase/write

operations, respectively. These bits are set by firmware

and cleared by hardware at the completion of the

operation.

The RD bit cannot be set when accessing program

memory (EEPGD = 1). Program memory is read using

table read instructions. See Section 6.1 “Table Reads

and Table Writes” regarding table reads.

Note: Interrupt flag bit, EEIF in the PIR2 register,

is set when write is complete. It must be

cleared in software.

PIC18F1230/1330

R/W-x R/W-x U-0 R/W-0 R/W-x R/W-0 R/S-0 R/S-0

EEPGD CFGS — FREE WRERR(1) WREN WR RD

bit 7 bit 0

Legend: S = Settable bit

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 EEPGD: Flash Program or Data EEPROM Memory Select bit

1 = Access Flash program memory

0 = Access data EEPROM memory

bit 6 CFGS: Flash Program/Data EEPROM or Configuration Select bit

1 = Access Configuration registers

0 = Access Flash program or data EEPROM memory

bit 5 Unimplemented: Read as ‘0’

bit 4 FREE: Flash Row Erase Enable bit

1 = Erase the program memory row addressed by TBLPTR on the next WR command

(cleared by completion of erase operation)

0 = Perform write-only

bit 3 WRERR: EEPROM Error Flag bit(1)

1 = A write operation is prematurely terminated

(MCLR or WDT Reset during self-timed erase or program operation)

0 = The write operation completed

bit 2 WREN: Erase/Write Enable bit

1 = Allows erase/write cycles

0 = Inhibits erase/write cycles

bit 1 WR: Write Control bit

1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle.

(The operation is self-timed and the bit is cleared by hardware once write is complete.

The WR bit can only be set (not cleared) in software.)

0 = Write cycle to is completed

bit 0 RD: Read Control bit

1 = Initiates a memory read. (Read takes one cycle. RD is cleared in hardware. The RD bit can only be

set (not cleared) in software. RD bit cannot be set when EEPGD = 1.)

0 = Read completed

Note 1: When a WRERR occurs, the EEPGD or FREE bit is not cleared. This allows tracing of the error condition.

PIC18F1230/1330

7.3 Reading the Data EEPROM

Memory

To read a data memory location, the user must write the

address to the EEADR register, clear the EEPGD

control bit (EECON1<7>) and then set control bit RD

(EECON1<0>). The data is available for the very next

instruction cycle; therefore, the EEDATA register can

be read by the next instruction. EEDATA will hold this

value until another read operation, or until it is written to

by the user (during a write operation).

7.4 Writing to the Data EEPROM

Memory

To write an EEPROM data location, the address must

first be written to the EEADR register and the data

written to the EEDATA register. The sequence in

Example 7-2 must be followed to initiate the write cycle.

The write will not begin if this sequence is not exactly

followed (write 55h to EECON2, write 0AAh to

EECON2, then set WR bit) for each byte. It is strongly

recommended that interrupts be disabled during this

code segment.

Additionally, the WREN bit in EECON1 must be set to

enable writes. This mechanism prevents accidental

writes to data EEPROM due to unexpected code

execution (i.e., runaway programs). The WREN bit

should be kept clear at all times, except when updating

the EEPROM. The WREN bit is not cleared

by hardware.

After a write sequence has been initiated, EECON1,

EEADR and EEDATA cannot be modified. The WR bit

will be inhibited from being set unless the WREN bit is

set. The WREN bit must be set on a previous instruc-

tion. Both WR and WREN cannot be set with the same

instruction.

At the completion of the write cycle, the WR bit is

cleared in hardware and the EEPROM Interrupt Flag bit

(EEIF) is set. The user may either enable this interrupt

or poll this bit. EEIF must be cleared by software.

7.5 Write Verify

Depending on the application, good programming

practice may dictate that the value written to the

memory should be verified against the original value.

This should be used in applications where excessive

writes can stress bits near the specification limit.

7.6 Protection Against Spurious Write

There are conditions when the device may not want to

write to the data EEPROM memory. To protect against

spurious EEPROM writes, various mechanisms have

been built-in. On power-up, the WREN bit is cleared.

Also, the Power-up Timer (72 ms duration) prevents

EEPROM write.

The write initiate sequence and the WREN bit together

help prevent an accidental write during brown-out,

power glitch, or software malfunction.

EXAMPLE 7-1: DATA EEPROM READ

EXAMPLE 7-2: DATA EEPROM WRITE

MOVLW DATA_EE_ADDR ;

MOVWF EEADR ; Data Memory Address to read

BCF EECON1, EEPGD ; Point to DATA memory

BSF EECON1, RD ; EEPROM Read

MOVF EEDATA, W ; W = EEDATA

MOVLW DATA_EE_ADDR ;

MOVWF EEADR ; Data Memory Address to write

MOVLW DATA_EE_DATA ;

MOVWF EEDATA ; Data Memory Value to write

BCF EECON1, EEPGD ; Point to DATA memory

BSF EECON1, WREN ; Enable writes

BCF INTCON, GIE ; Disable Interrupts

MOVLW 55h ;

Required MOVWF EECON2 ; Write 55h

Sequence MOVLW 0AAh ;

MOVWF EECON2 ; Write 0AAh

BSF EECON1, WR ; Set WR bit to begin write

BSF INTCON, GIE ; Enable Interrupts

SLEEP ; Wait for interrupt to signal write complete

BCF EECON1, WREN ; Disable writes

PIC18F1230/1330
DS39758C-page 78 Advance Information © 2007 Microchip Technology Inc.
7.7 Operation During Code-Protect
Data EEPROM memory has its own code-protect bits
in Configuration Words. External read and write
operations are disabled if either of these mechanisms
are enabled.
The microcontroller itself can both read and write to the
internal data EEPROM, regardless of the state of the
code-protect Configuration bit. Refer to Section 19.0
“Special Features of the CPU” for additional
information.
7.8 Using the Data EEPROM
The data EEPROM is a high-endurance, byte
addressable array that has been optimized for the
storage of frequently changing information (e.g.,
program variables or other data that are updated
often). Frequently changing values will typically be
updated more often than specification D124 or D124A.
If this is not the case, an array refresh must be
performed. For this reason, variables that change
infrequently (such as constants, IDs, calibration, etc.)
should be stored in Flash program memory. 
A simple data EEPROM refresh routine is shown in
Example 7-3.
EXAMPLE 7-3: DATA EEPROM REFRESH ROUTINE
TABLE 7-1: REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY 
Note: If data EEPROM is only used to store
constants and/or data that changes rarely,
an array refresh is likely not required. See
specification D124 or D124A.
CLRF EEADR ; Start at address 0
BCF EECON1, CFGS ; Set for memory
BCF EECON1, EEPGD ; Set for Data EEPROM
BCF INTCON, GIE ; Disable interrupts
BSF EECON1, WREN ; Enable writes
LOOP ; Loop to refresh array
BSF EECON1, RD ; Read current address
MOVLW 55h ;
MOVWF EECON2 ; Write 55h
MOVLW 0AAh ;
MOVWF EECON2 ; Write 0AAh
BSF EECON1, WR ; Set WR bit to begin write
BTFSC EECON1, WR ; Wait for write to complete
BRA $-2
INCFSZ EEADR, F ; Increment address
BRA Loop ; Not zero, do it again
BCF EECON1, WREN ; Disable writes
BSF INTCON, GIE ; Enable interrupts
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values on 
Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
EEADR EEPROM Address Register 43
EEDATA EEPROM Data Register 43
EECON2 EEPROM Control Register 2 (not a physical register) 43
EECON1 EEPGD CFGS — FREE WRERR WREN WR RD 43
IPR2 OSCFIP —— EEIP —LVDIP ——43
PIR2 OSCFIF —— EEIF —LVDIF ——43
PIE2 OSCFIE —— EEIE —LVDIE ——43
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.

PIC18F1230/1330

8.0 8 x 8 HARDWARE MULTIPLIER

8.1 Introduction

All PIC18 devices include an 8 x 8 hardware multiplier

as part of the ALU. The multiplier performs an unsigned

operation and yields a 16-bit result that is stored in the

Product register pair, PRODH:PRODL. The multiplier’s

operation does not affect any flags in the STATUS

Making multiplication a hardware operation allows it to

be completed in a single instruction cycle. This has the

advantages of higher computational throughput and

reduced code size for multiplication algorithms and

allows the PIC18 devices to be used in many

applications previously reserved for digital signal

processors. A comparison of various hardware and

software multiply operations, along with the savings in

memory and execution time, is shown in Table 8-1.

8.2 Operation

Example 8-1 shows the instruction sequence for an 8 x 8

unsigned multiplication. Only one instruction is required

when one of the arguments is already loaded in the

WREG register.

Example 8-2 shows the sequence to do an 8 x 8 signed

multiplication. To account for the sign bits of the

arguments, each argument’s Most Significant bit (MSb)

is tested and the appropriate subtractions are done.

EXAMPLE 8-1: 8 x 8 UNSIGNED

MULTIPLY ROUTINE

EXAMPLE 8-2: 8 x 8 SIGNED MULTIPLY

ROUTINE

TABLE 8-1: PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS

MOVF ARG1, W ;

MULWF ARG2 ; ARG1 * ARG2 ->

; PRODH:PRODL

MOVF ARG1, W

MULWF ARG2 ; ARG1 * ARG2 ->

; PRODH:PRODL

BTFSC ARG2, SB ; Test Sign Bit

SUBWF PRODH, F ; PRODH = PRODH

; - ARG1

MOVF ARG2, W

BTFSC ARG1, SB ; Test Sign Bit

SUBWF PRODH, F ; PRODH = PRODH

; - ARG2

Routine Multiply Method

Program

Memory

(Words)

Cycles

(Max)

Time

@ 40 MHz @ 10 MHz @ 4 MHz

8 x 8 unsigned Without hardware multiply 13 69 6.9 μs27.6 μs69 μs

Hardware multiply 1 1 100 ns 400 ns 1 μs

8 x 8 signed Without hardware multiply 33 91 9.1 μs36.4 μs91 μs

Hardware multiply 6 6 600 ns 2.4 μs6 μs

16 x 16 unsigned Without hardware multiply 21 242 24.2 μs96.8 μs 242 μs

Hardware multiply 28 28 2.8 μs 11.2 μs28 μs

16 x 16 signed Without hardware multiply 52 254 25.4 μs 102.6 μs 254 μs

Hardware multiply 35 40 4.0 μs16.0 μs40 μs

PIC18F1230/1330

Example 8-3 shows the sequence to do a 16 x 16

unsigned multiplication. Equation 8-1 shows the

algorithm that is used. The 32-bit result is stored in four

registers (RES3:RES0).

EQUATION 8-1: 16 x 16 UNSIGNED

MULTIPLICATION

ALGORITHM

EXAMPLE 8-3: 16 x 16 UNSIGNED

MULTIPLY ROUTINE

Example 8-4 shows the sequence to do a 16 x 16

signed multiply. Equation 8-2 shows the algorithm

used. The 32-bit result is stored in four registers

(RES3:RES0). To account for the sign bits of the

arguments, the MSb for each argument pair is tested

and the appropriate subtractions are done.

EQUATION 8-2: 16 x 16 SIGNED

MULTIPLICATION

ALGORITHM

EXAMPLE 8-4: 16 x 16 SIGNED

MULTIPLY ROUTINE

RES3:RES0= ARG1H:ARG1L • ARG2H:ARG2L

= (ARG1H • ARG2H • 216) +

(ARG1H • ARG2L • 28) +

(ARG1L • ARG2H • 28) +

(ARG1L • ARG2L)

MOVF ARG1L, W

MULWF ARG2L ; ARG1L * ARG2L->

; PRODH:PRODL

MOVFF PRODH, RES1 ;

MOVFF PRODL, RES0 ;

;

MOVF ARG1H, W

MULWF ARG2H ; ARG1H * ARG2H->

; PRODH:PRODL

MOVFF PRODH, RES3 ;

MOVFF PRODL, RES2 ;

;

MOVF ARG1L, W

MULWF ARG2H ; ARG1L * ARG2H->

; PRODH:PRODL

MOVF PRODL, W ;

ADDWF RES1, F ; Add cross

MOVF PRODH, W ; products

ADDWFC RES2, F ;

CLRF WREG ;

ADDWFC RES3, F ;

;

MOVF ARG1H, W ;

MULWF ARG2L ; ARG1H * ARG2L->

; PRODH:PRODL

MOVF PRODL, W ;

ADDWF RES1, F ; Add cross

MOVF PRODH, W ; products

ADDWFC RES2, F ;

CLRF WREG ;

ADDWFC RES3, F ;

RES3:RES0=ARG1H:ARG1L • ARG2H:ARG2L

= (ARG1H • ARG2H • 216) +

(ARG1H • ARG2L • 28) +

(ARG1L • ARG2H • 28) +

(ARG1L • ARG2L) +

(-1 • ARG2H<7> • ARG1H:ARG1L • 216) +

(-1 • ARG1H<7> • ARG2H:ARG2L • 216)

MOVF ARG1L, W

MULWF ARG2L ; ARG1L * ARG2L ->

; PRODH:PRODL

MOVFF PRODH, RES1 ;

MOVFF PRODL, RES0 ;

;

MOVF ARG1H, W

MULWF ARG2H ; ARG1H * ARG2H ->

; PRODH:PRODL

MOVFF PRODH, RES3 ;

MOVFF PRODL, RES2 ;

;

MOVF ARG1L, W

MULWF ARG2H ; ARG1L * ARG2H ->

; PRODH:PRODL

MOVF PRODL, W ;

ADDWF RES1, F ; Add cross

MOVF PRODH, W ; products

ADDWFC RES2, F ;

CLRF WREG ;

ADDWFC RES3, F ;

;

MOVF ARG1H, W ;

MULWF ARG2L ; ARG1H * ARG2L ->

; PRODH:PRODL

MOVF PRODL, W ;

ADDWF RES1, F ; Add cross

MOVF PRODH, W ; products

ADDWFC RES2, F ;

CLRF WREG ;

ADDWFC RES3, F ;

;

BTFSS ARG2H, 7 ; ARG2H:ARG2L neg?

BRA SIGN_ARG1 ; no, check ARG1

MOVF ARG1L, W ;

SUBWF RES2 ;

MOVF ARG1H, W ;

SUBWFB RES3

;

SIGN_ARG1

BTFSS ARG1H, 7 ; ARG1H:ARG1L neg?

BRA CONT_CODE ; no, done

MOVF ARG2L, W ;

SUBWF RES2 ;

MOVF ARG2H, W ;

SUBWFB RES3

;

CONT_CODE

PIC18F1230/1330

9.0 I/O PORTS

Depending on the device selected and features

enabled, there are up to five ports available. Some pins

of the I/O ports are multiplexed with an alternate

function from the peripheral features on the device. In

general, when a peripheral is enabled, that pin may not

be used as a general purpose I/O pin.

Each port has three registers for its operation. These

registers are:

• TRIS register (Data Direction register)

• PORT register (reads the levels on the pins of the

device)

• LAT register (Output Latch register)

The Output Latch (LAT register) is useful for read-

modify-write operations on the value that the I/O pins

are driving.

A simplified model of a generic I/O port, without the

interfaces to other peripherals, is shown in Figure 9-1.

FIGURE 9-1: GENERIC I/O PORT

OPERATION

9.1 PORTA, TRISA and LATA Registers

PORTA is an 8-bit wide, bidirectional port. The

corresponding Data Direction register is TRISA. Setting

a TRISA bit (= 1) will make the corresponding PORTA

pin an input (i.e., put the corresponding output driver in

a high-impedance mode). Clearing a TRISA bit (= 0)

will make the corresponding PORTA pin an output (i.e.,

put the contents of the output latch on the selected pin).

Reading the PORTA register reads the status of the

pins, whereas writing to it, will write to the port latch.

The Output Latch (LATA) register is also memory

mapped. Read-modify-write operations on the LATA

PORTA.

Pins RA6 and RA7 are multiplexed with the main

oscillator pins; they are enabled as oscillator or I/O pins

by the selection of the main oscillator in the Configura-

tion register (see Section 19.1 “Configuration Bits”

for details). When they are not used as port pins, RA6

and RA7 and their associated TRIS and LAT bits are

read as ‘0’.

The RA0 pin is multiplexed with one of the analog

inputs, one of the external interrupt inputs, one of the

interrupt-on-change inputs and one of the analog

comparator inputs to become RA0/AN0/INT0/KBI0/

CMP0 pin.

The RA1 pin is multiplexed with one of the analog

inputs, one of the external interrupt inputs and one of

the interrupt-on-change inputs to become RA1/AN1/

INT1/KBI1 pin.

Pins RA2 and RA3 are multiplexed with the Enhanced

USART transmission and reception input (see

Section 19.1 “Configuration Bits” for details).

The RA4 pin is multiplexed with the Timer0 module

clock input, one of the analog inputs and the analog

VREF+ input to become the RA4/T0CKI/AN2/VREF+ pin.

The Fault detect input for PWM FLTA is multiplexed with

pins RA5 and RA7. Its placement is decided by clearing

or setting the FLTAMX bit of Configuration Register 3H.

The TRISA register controls the direction of the PORTA

pins, even when they are being used as analog inputs.

The user must ensure the bits in the TRISA register are

maintained set when using them as analog inputs.

EXAMPLE 9-1: INITIALIZING PORTA

Data

Bus

WR LAT

WR TRIS

RD Port

Data Latch

TRIS Latch

RD TRIS

Input

Buffer

I/O pin(1)

RD LAT

or Port

Note 1: I/O pins have diode protection to VDD and VSS.

Note: On a Power-on Reset, RA0, RA1, RA4

and RA5 are configured as analog inputs

and read as ‘0’. RA2 and RA3 are

configured as digital inputs.

CLRF PORTA ; Initialize PORTA by

; clearing output

; data latches

CLRF LATA ; Alternate method

; to clear output

; data latches

MOVLW 07h ; Configure A/D

MOVWF ADCON1 ; for digital inputs

MOVWF 07h ; Configure comparators

MOVWF CMCON ; for digital input

MOVLW 0CFh ; Value used to

; initialize data

; direction

MOVWF TRISA ; Set RA<7:6,3:0> as inputs

; RA<5:4> as outputs

PIC18F1230/1330

TABLE 9-1: PORTA I/O SUMMARY

Pin Function TRIS

Setting I/O I/O

Type Description

RA0/AN0/INT0/

KBI0/CMP0

RA0 0O DIG LATA<0> data output; not affected by analog input.

1I TTL PORTA<0> data input; disabled when analog input enabled.

AN0 1I ANA Analog input 0.

INT0 1I ST External interrupt 0.

KBI0 1I TTL Interrupt-on-change pin.

CMP0 1I ANA Comparator 0 input.

RA1/AN1/INT1/

KBI1

RA1 0O DIG LATA<1> data output; not affected by analog input.

1I TTL PORTA<1> data input; disabled when analog input enabled.

AN1 1I ANA Analog input 1.

INT1 1I ST External interrupt 1.

KBI1 1I TTL Interrupt-on-change pin.

RA2/TX/CK RA2 0O DIG LATA<2> data output; not affected by analog input. Disabled when

CVREF output enabled.

1I TTL PORTA<2> data input. Disabled when analog functions enabled;

disabled when CVREF output enabled.

TX 00 DIG EUSART asynchronous transmit.

CK 0O DIG EUSART synchronous clock.

1IST

RA3/RX/DT RA3 0O DIG LATA<3> data output; not affected by analog input.

1I TTL PORTA<3> data input; disabled when analog input enabled.

RX 1I ANA EUSART asynchronous receive.

DT 0O DIG EUSART synchronous data.

1ITTL

RA4/T0CKI/AN2/

VREF+

RA4 0O DIG LATA<4> data output.

1I ST PORTA<4> data input; default configuration on POR.

T0CKI 1I ST Timer0 external clock input.

AN2 1I ANA Analog input 2.

VREF+1I ANA A/D reference voltage (high) input.

MCLR/VPP/RA5/

FLTA

MCLR 1I ST Master Clear (Reset) input. This pin is an active-low Reset to the device.

VPP 1I ANA Programming voltage input.

RA5 1I ST Digital input.

FLTA(1) 1I ST Fault detect input for PWM.

RA6/OSC2/CLKO/

T1OSO/T1CKI/AN3

RA6 0O DIG LATA<6> data output. Enabled in RCIO, INTIO2 and ECIO modes only.

1I ST PORTA<6> data input. Enabled in RCIO, INTIO2 and ECIO modes only.

OSC2 0O ANA Oscillator crystal output or external clock source output.

CLKO 0O ANA Oscillator crystal output.

T1OSO(2) 0O ANA Timer1 oscillator output.

T1CKI(2) 1I ST Timer1 clock input.

AN3 1I ANA Analog input 3.

RA7/OSC1/CLKI/

T1OSI/FLTA

RA7 0O DIG LATA<7> data output. Disabled in external oscillator modes.

1I TTL PORTA<7> data input. Disabled in external oscillator modes.

OSC1 1I ANA Oscillator crystal input or external clock source input.

CLKI 1I ANA External clock source input.

T1OSI(2) 1I ANA Timer1 oscillator input.

FLTA(1) 1I ST Fault detect input for PWM.

Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output;

x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).

Note 1: Placement of FLTA depends on the value of Configuration bit, FLTAMX, of CONFIG3H.

2: Placement of T1OSI and T1OSO/T1CKI depends on the value of Configuration bit, T1OSCMX, of CONFIG3H.

PIC18F1230/1330

TABLE 9-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Reset

Values

on Page:

PORTA RA7(1) RA6(1) RA5 RA4 RA3 RA2 RA1 RA0 44

LATA LATA7(1) LATA6(1) PORTA Output Latch Register (Read and Write to Data Latch) 43

TRISA TRISA7(1) TRISA6(1) PORTA Data Direction Control Register 43

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41

INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP 41

ADCON1 — — — VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 42

CMCON C2OUT C1OUT C0OUT — — CMEN2 CMEN1 CMEN0 42

CVRCON CVREN —CVRR CVRSS CVR3 CVR2 CVR1 CVR0 42

Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTA.

Note 1: RA7:RA6 and their associated latch and data direction bits are enabled as I/O pins based on oscillator

configuration; otherwise, they are read as ‘0’.

PIC18F1230/1330

9.2 PORTB, TRISB and LATB

Registers

PORTB is an 8-bit wide, bidirectional port. The

corresponding Data Direction register is TRISB. Setting

a TRISB bit (= 1) will make the corresponding PORTB

pin an input (i.e., put the corresponding output driver in

a high-impedance mode). Clearing a TRISB bit (= 0)

will make the corresponding PORTB pin an output (i.e.,

put the contents of the output latch on the selected pin).

The Output Latch register (LATB) is also memory

mapped. Read-modify-write operations on the LATB

PORTB.

EXAMPLE 9-2: INITIALIZING PORTB

Each of the PORTB pins has a weak internal pull-up. A

single control bit can turn on all the pull-ups. This is

performed by clearing bit, RBPU (INTCON2<7>). The

weak pull-up is automatically turned off when the port

pin is configured as an output. The pull-ups are

disabled on a Power-on Reset.

Pins RB0, RB1 and RB4:RB7 are multiplexed with the

Power Control PWM outputs.

Pins RB2 and RB3 are multiplexed with external interrupt

inputs, interrupt-on-change input, the analog comparator

inputs and the Timer1 oscillator input and output to

become RB2/INT2/KBI2/CMP2/T1OSO/T1CKI and

RB3/INT3/KNBI3/CMP1/T1OSI, respectively.

When the interrupt-on-change feature is enabled, only

pins configured as inputs can cause this interrupt to

occur (i.e., any RB2, RB3, RA0 and RA1 pin configured

as an output is excluded from the interrupt-on-change

comparison). The input pins (RB2, RB3, RA0 and RA1)

are compared with the old value latched on the last

read of PORTA and PORTB. The “mismatch” outputs of

these pins are ORed together to generate the RB Port

Change Interrupt with Flag bit, RBIF (INTCON<0>).

This interrupt can wake the device from Sleep mode, or

any of the Idle modes. The user, in the Interrupt Service

Routine, can clear the interrupt in the following manner:

a) Any read or write of PORTA and/or PORTB

(except with the MOVFF (ANY), PORTA and

MOVFF (ANY), PORTB instructions).

b) Clear flag bit, RBIF.

A mismatch condition will continue to set flag bit, RBIF.

Reading PORTA and PORTB will end the mismatch

condition and allow flag bit, RBIF, to be cleared.

The interrupt-on-change feature is recommended for

wake-up on key depression operation and operations

where PORTA and PORTB are used for the interrupt-

on-change feature. Polling of PORTA and PORTB is

not recommended while using the interrupt-on-change

feature.

Note: On a Power-on Reset, PORTB is

configured as digital inputs except for RB2

and RB3.

RB2 and RB3 are configured as analog

inputs when the T1OSCMX bit of Configu-

ration Register 3H is cleared. Otherwise,

RB2 and RB3 are also configured as

digital inputs.

CLRF PORTB ; Initialize PORTB by

; clearing output

; data latches

CLRF LATB ; Alternate method

; to clear output

; data latches

MOVLW 0Fh ; Set RB<4:0> as

MOVWF ADCON1 ; digital I/O pins

; (required if config bit

; PBADEN is set)

MOVLW 0CFh ; Value used to

; initialize data

; direction

MOVWF TRISB ; Set RB<3:0> as inputs

; RB<5:4> as outputs

; RB<7:6> as inputs

PIC18F1230/1330

TABLE 9-3: PORTB I/O SUMMARY

Pin Function TRIS

Setting I/O I/O

Type Description

RB0/PWM0 RB0 0O DIG LATB<0> data output; not affected by analog input.

1I TTL PORTB<0> data input; weak pull-up when RBPU bit is cleared.

Disabled when analog input enabled.(1)

PWM0 0O DIG PWM module output PWM0.

RB1PWM1 RB1 0O DIG LATB<1> data output; not affected by analog input.

1I TTL PORTB<1> data input; weak pull-up when RBPU bit is cleared.

Disabled when analog input enabled.(1)

PWM1 0O DIG PWM module output PWM1.

RB2/INT2/KBI2/

CMP2/T1OSO/

T1CKI

RB2 0O DIG LATB<2> data output; not affected by analog input.

1I TTL PORTB<2> data input; weak pull-up when RBPU bit is cleared.

Disabled when analog input enabled.(1)

INT2 1I ST External interrupt 2 input.

KBI2 1I TTL Interrupt-on-change pin.

CMP2 1I ANA Comparator 2 input.

T1OSO(2) 0O ANA Timer1 oscillator output.

T1CKI(2) 1I ST Timer1 clock input.

RB3/INT3/KBI3/

CMP1/T1OSI

RB3 0O DIG LATB<3> data output; not affected by analog input.

1I TTL PORTB<3> data input; weak pull-up when RBPU bit is cleared.

Disabled when analog input enabled.(1)

INT3 1I ST External interrupt 3 input.

KBI3 1I TTL Interrupt-on-change pin.

CMP1 1I ANA Comparator 1 input.

T1OSI(2) 1I ANA Timer1 oscillator input.

RB4/PWM2 RB4 0O DIG LATB<4> data output; not affected by analog input.

1I TTL PORTB<4> data input; weak pull-up when RBPU bit is cleared.

Disabled when analog input enabled.(1)

PWM2 0O DIG PWM module output PWM2.

RB5/PWM3 RB5 0O DIG LATB<5> data output.

1I TTL PORTB<5> data input; weak pull-up when RBPU bit is cleared.

PWM3 0O DIG PWM module output PWM3.

RB6/PWM4/PGC RB6 0O DIG LATB<6> data output.

1I TTL PORTB<6> data input; weak pull-up when RBPU bit is cleared.

PWM4 0O DIG PWM module output PWM4.

PGC 1I ST In-Circuit Debugger and ICSP™ programming clock pin.

RB7/PWM5/PGD RB7 0O DIG LATB<7> data output.

1I TTL PORTB<7> data input; weak pull-up when RBPU bit is cleared.

PWM5 0O TTL PWM module output PWM4.

PGD 0O DIG In-Circuit Debugger and ICSP programming data pin.

Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output;

x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).

Note 1: Configuration on POR is determined by the PBADEN Configuration bit. Pins are configured as analog inputs by default

when PBADEN is set and digital inputs when PBADEN is cleared.

2: Placement of T1OSI and T1OSO/T1CKI depends on the value of Configuration bit, T1OSCMX, of CONFIG3H.

PIC18F1230/1330

TABLE 9-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Reset

Values

on Page:

PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 44

LATB PORTB Output Latch Register (Read and Write to Data Latch) 43

TRISB PORTB Data Direction Control Register 43

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41

INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP 41

INTCON3 INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF 41

CMCON C2OUT C1OUT C0OUT —— CMEN2 CMEN1 CMEN0 42

Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTB.

PIC18F1230/1330

10.0 INTERRUPTS

The PIC18F1230/1330 devices have multiple interrupt

sources and an interrupt priority feature that allows

most interrupt sources to be assigned a high-priority

level or a low-priority level. The high-priority interrupt

vector is at 0008h and the low-priority interrupt vector

is at 0018h. High-priority interrupt events will interrupt

any low-priority interrupts that may be in progress.

There are thirteen registers which are used to control

interrupt operation. These registers are:

• RCON

•INTCON

• INTCON2

• INTCON3

• PIR1, PIR2, PIR3

• PIE1, PIE2, PIE3

• IPR1, IPR2, IPR3

It is recommended that the Microchip header files

supplied with MPLAB® IDE be used for the symbolic bit

names in these registers. This allows the assembler/

compiler to automatically take care of the placement of

these bits within the specified register.

In general, interrupt sources have three bits to control

their operation. They are:

•Flag bit to indicate that an interrupt event

occurred

•Enable bit that allows program execution to

branch to the interrupt vector address when the

flag bit is set

•Priority bit to select high priority or low priority

The interrupt priority feature is enabled by setting the

IPEN bit (RCON<7>). When interrupt priority is

enabled, there are two bits which enable interrupts

globally. Setting the GIEH bit (INTCON<7>) enables all

interrupts that have the priority bit set (high priority).

Setting the GIEL bit (INTCON<6>) enables all

interrupts that have the priority bit cleared (low priority).

When the interrupt flag, enable bit and appropriate

global interrupt enable bit are set, the interrupt will

vector immediately to address 0008h or 0018h,

depending on the priority bit setting. Individual

interrupts can be disabled through their corresponding

enable bits.

When the IPEN bit is cleared (default state), the

interrupt priority feature is disabled and interrupts are

compatible with PIC® mid-range devices. In

Compatibility mode, the interrupt priority bits for each

source have no effect. INTCON<6> is the PEIE bit,

which enables/disables all peripheral interrupt sources.

INTCON<7> is the GIE bit, which enables/disables all

interrupt sources. All interrupts branch to address

0008h in Compatibility mode.

When an interrupt is responded to, the global interrupt

enable bit is cleared to disable further interrupts. If the

IPEN bit is cleared, this is the GIE bit. If interrupt priority

levels are used, this will be either the GIEH or GIEL bit.

High-priority interrupt sources can interrupt a low-

priority interrupt. Low-priority interrupts are not

processed while high-priority interrupts are in progress.

The return address is pushed onto the stack and the

PC is loaded with the interrupt vector address (0008h

or 0018h). Once in the Interrupt Service Routine, the

source(s) of the interrupt can be determined by polling

the interrupt flag bits. The interrupt flag bits must be

cleared in software before re-enabling interrupts to

avoid recursive interrupts.

The “return from interrupt” instruction, RETFIE, exits

the interrupt routine and sets the GIE bit (GIEH or GIEL

if priority levels are used), which re-enables interrupts.

For external interrupt events, such as the INT pins or

the PORTB input change interrupt, the interrupt latency

will be three to four instruction cycles. The exact

latency is the same for one or two-cycle instructions.

Individual interrupt flag bits are set, regardless of the

status of their corresponding enable bit or the GIE bit.

Note: Do not use the MOVFF instruction to modify

any of the interrupt control registers while

any interrupt is enabled. Doing so may

cause erratic microcontroller behavior.

PIC18F1230/1330

FIGURE 10-1: PIC18 INTERRUPT LOGIC

RBIE

GIE/GIEH

PEIE/GIEL

Wake-up if in

Interrupt to CPU

Vector to Location

0008h

INT2IF

INT2IE

INT2IP

INT1IF

INT1IE

INT1IP

TMR0IF

TMR0IE

TMR0IP

RBIF

RBIE

RBIP

IPEN

RBIF

RBIP

INT2IF

INT2IE

INT2IP

INT0IF

INT0IE

INT1IF

INT1IE

PEIE/GIEL

Interrupt to CPU

Vector to Location

IPEN

0018h

Peripheral Interrupt Flag bit

Peripheral Interrupt Enable bit

Peripheral Interrupt Priority bit

Peripheral Interrupt Flag bit

Peripheral Interrupt Enable bit

Peripheral Interrupt Priority bit

ADIF

ADIE

ADIP

PTIF

PTIE

PTIP

Additional Peripheral Interrupts

ADIF

ADIE

ADIP

High-Priority Interrupt Generation

Low-Priority Interrupt Generation

PTIF

PTIE

PTIP

Additional Peripheral Interrupts

Idle or Sleep modes

GIE/GIEH

TMR0IE

TMR0IF

TMR0IP

INT1IP

From Power Control PWM

Interrupt Logic

From Power Control

PWM Interrupt Logic

PIC18F1230/1330

10.1 INTCON Registers

The INTCON registers are readable and writable

registers, which contain various enable, priority and

flag bits.

Note: Interrupt flag bits are set when an interrupt

condition occurs, regardless of the state of

its corresponding enable bit or the global

interrupt enable bit. User software should

ensure the appropriate interrupt flag bits

are clear prior to enabling an interrupt.

This feature allows for software polling.

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x

GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF(1)

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 GIE/GIEH: Global Interrupt Enable bit

When IPEN = 0:

1 = Enables all unmasked interrupts

0 = Disables all interrupts

When IPEN = 1:

1 = Enables all high-priority interrupts

0 = Disables all interrupts

bit 6 PEIE/GIEL: Peripheral Interrupt Enable bit

When IPEN = 0:

1 = Enables all unmasked peripheral interrupts

0 = Disables all peripheral interrupts

When IPEN = 1:

1 = Enables all low-priority peripheral interrupts

0 = Disables all low-priority peripheral interrupts

bit 5 TMR0IE: TMR0 Overflow Interrupt Enable bit

1 = Enables the TMR0 overflow interrupt

0 = Disables the TMR0 overflow interrupt

bit 4 INT0IE: INT0 External Interrupt Enable bit

1 = Enables the INT0 external interrupt

0 = Disables the INT0 external interrupt

bit 3 RBIE: RB Port Change Interrupt Enable bit

1 = Enables the RB port change interrupt

0 = Disables the RB port change interrupt

bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit

1 = TMR0 register has overflowed (must be cleared in software)

0 = TMR0 register did not overflow

bit 1 INT0IF: INT0 External Interrupt Flag bit

1 = The INT0 external interrupt occurred (must be cleared in software)

0 = The INT0 external interrupt did not occur

bit 0 RBIF: RB Port Change Interrupt Flag bit(1)

1 = At least one of the RB7:RB4 pins changed state (must be cleared in software)

0 = None of the RB7:RB4 pins have changed state

Note 1: A mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and

allow the bit to be cleared.

PIC18F1230/1330

R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1

RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 RBPU: PORTB Pull-up Enable bit

1 = All PORTB pull-ups are disabled

0 = PORTB pull-ups are enabled by individual port latch values

bit 6 INTEDG0: External Interrupt 0 Edge Select bit

1 = Interrupt on rising edge

0 = Interrupt on falling edge

bit 5 INTEDG1: External Interrupt 1 Edge Select bit

1 = Interrupt on rising edge

0 = Interrupt on falling edge

bit 4 INTEDG2: External Interrupt 2 Edge Select bit

1 = Interrupt on rising edge

0 = Interrupt on falling edge

bit 3 INTEDG3: External Interrupt 3 Edge Select bit

1 = Interrupt on rising edge

0 = Interrupt on falling edge

bit 2 TMR0IP: TMR0 Overflow Interrupt Priority bit

1 = High priority

0 = Low priority

bit 1 INT3IP: INT3 External Interrupt Priority bit

1 = High priority

0 = Low priority

bit 0 RBIP: RB Port Change Interrupt Priority bit

1 = High priority

0 = Low priority

Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding

enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits

are clear prior to enabling an interrupt. This feature allows for software polling.

PIC18F1230/1330

R/W-1 R/W-1 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 INT2IP: INT2 External Interrupt Priority bit

1 = High priority

0 = Low priority

bit 6 INT1IP: INT1 External Interrupt Priority bit

1 = High priority

0 = Low priority

bit 5 INT3IE: INT3 External Interrupt Enable bit

1 = Enables the INT3 external interrupt

0 = Disables the INT3 external interrupt

bit 4 INT2IE: INT2 External Interrupt Enable bit

1 = Enables the INT2 external interrupt

0 = Disables the INT2 external interrupt

bit 3 INT1IE: INT1 External Interrupt Enable bit

1 = Enables the INT1 external interrupt

0 = Disables the INT1 external interrupt

bit 2 INT3IF: INT3 External Interrupt Flag bit

1 = The INT3 external interrupt occurred (must be cleared in software)

0 = The INT3 external interrupt did not occur

bit 1 INT2IF: INT2 External Interrupt Flag bit

1 = The INT2 external interrupt occurred (must be cleared in software)

0 = The INT2 external interrupt did not occur

bit 0 INT1IF: INT1 External Interrupt Flag bit

1 = The INT1 external interrupt occurred (must be cleared in software)

0 = The INT1 external interrupt did not occur

Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding

enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits

are clear prior to enabling an interrupt. This feature allows for software polling.

PIC18F1230/1330

10.2 PIR Registers

The PIR registers contain the individual flag bits for the

peripheral interrupts. Due to the number of peripheral

interrupt sources, there are three Peripheral Interrupt

Request (Flag) registers (PIR1, PIR2 and PIR3).

Note 1: Interrupt flag bits are set when an interrupt

condition occurs, regardless of the state

of its corresponding enable bit or the Glo-

bal Interrupt Enable bit, GIE

(INTCON<7>).

2: User software should ensure the

appropriate interrupt flag bits are cleared

prior to enabling an interrupt and after

servicing that interrupt.

U-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0

— ADIF RCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 Unimplemented: Read as ‘0’

bit 6 ADIF: A/D Converter Interrupt Flag bit

1 = An A/D conversion completed (must be cleared in software)

0 = The A/D conversion is not complete

bit 5 RCIF: EUSART Receive Interrupt Flag bit

1 = The EUSART receive buffer, RCREG, is full (cleared when RCREG is read)

0 = The EUSART receive buffer is empty

bit 4 TXIF: EUSART Transmit Interrupt Flag bit

1 = The EUSART transmit buffer, TXREG, is empty (cleared when TXREG is written)

0 = The EUSART transmit buffer is full

bit 3 CMP2IF: Analog Comparator 2 Flag bit

1 = The output of CMP2 has changed since last read

0 = The output of CMP2 has not changed since last read

bit 2 CMP1IF: Analog Comparator 1 Flag bit

1 = The output of CMP1 has changed since last read

0 = The output of CMP1 has not changed since last read

bit 1 CMP0IF: Analog Comparator 0 Flag bit

1 = The output of CMP0 has changed since last read

0 = The output of CMP0 has not changed since last read

bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit

1 = TMR1 register overflowed (must be cleared in software)

0 = TMR1 register did not overflow

PIC18F1230/1330

R/W-0 U-0 U-0 R/W-0 U-0 R/W-0 U-0 U-0

OSCFIF —— EEIF —LVDIF — —

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 OSCFIF: Oscillator Fail Interrupt Flag bit

1 = Device oscillator failed, clock input has changed to INTOSC (must be cleared in software)

0 = Device clock operating

bit 6-5 Unimplemented: Read as ‘0’

bit 4 EEIF: Data EEPROM/Flash Write Operation Interrupt Flag bit

1 = The write operation is complete (must be cleared in software)

0 = The write operation is not complete or has not been started

bit 3 Unimplemented: Read as ‘0’

bit 2 LVDIF: Low-Voltage Detect Interrupt Flag bit

1 = A low-voltage condition occurred

0 = A low-voltage condition has not occurred

bit 1-0 Unimplemented: Read as ‘0’

U-0 U-0 U-0 R/W-0 U-0 U-0 U-0 U-0

— — —PTIF— — — —

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-5 Unimplemented: Read as ‘0’

bit 4 PTIF: PWM Time Base Interrupt bit

1 = PWM time base matched the value in PTPER register. Interrupt is issued according to the

postscaler settings. PTIF must be cleared in software.

0 = PWM time base has not matched the value in PTPER register

bit 3-0 Unimplemented: Read as ‘0’

PIC18F1230/1330

10.3 PIE Registers

The PIE registers contain the individual enable bits for

the peripheral interrupts. Due to the number of

peripheral interrupt sources, there are three Peripheral

Interrupt Enable registers (PIE1, PIE2 and PIE3). When

IPEN = 0, the PEIE bit must be set to enable any of

these peripheral interrupts.

U-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0

— ADIE RCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 Unimplemented: Read as ‘0’

bit 6 ADIE: A/D Converter Interrupt Enable bit

1 = Enables the A/D interrupt

0 = Disables the A/D interrupt

bit 5 RCIE: EUSART Receive Interrupt Enable bit

1 = Enables the EUSART receive interrupt

0 = Disables the EUSART receive interrupt

bit 4 TXIE: EUSART Transmit Interrupt Enable bit

1 = Enables the EUSART transmit interrupt

0 = Disables the EUSART transmit interrupt

bit 3 CMP2IE: Analog Comparator 2 Interrupt Enable bit

1 = Enables the CMP2 interrupt

0 = Disables the CMP2 interrupt

bit 2 CMP1IE: Analog Comparator 1 Interrupt Enable bit

1 = Enables the CMP1 interrupt

0 = Disables the CMP1 interrupt

bit 1 CMP0IE: Analog Comparator 0 Interrupt Enable bit

1 = Enables the CMP0 interrupt

0 = Disables the CMP0 interrupt

bit 0 TMR1IE: TMR1 Overflow Interrupt Enable bit

1 = Enables the TMR1 overflow interrupt

0 = Disables the TMR1 overflow interrupt

PIC18F1230/1330

R/W-0 U-0 U-0 R/W-0 U-0 R/W-0 U-0 U-0

OSCFIE —— EEIE —LVDIE — —

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 OSCFIE: Oscillator Fail Interrupt Enable bit

1 = Enabled

0 =Disabled

bit 6-5 Unimplemented: Read as ‘0’

bit 4 EEIE: Data EEPROM/Flash Write Operation Interrupt Enable bit

1 = Enabled

0 =Disabled

bit 3 Unimplemented: Read as ‘0’

bit 2 LVDIE: Low-Voltage Detect Interrupt Enable bit

1 = Enabled

0 =Disabled

bit 1-0 Unimplemented: Read as ‘0’

U-0 U-0 U-0 R/W-0 U-0 U-0 U-0 U-0

— — —PTIE— — — —

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-5 Unimplemented: Read as ‘0’

bit 4 PTIE: PWM Time Base Interrupt Enable bit

1 = PWM enabled

0 = PWM disabled

bit 3-0 Unimplemented: Read as ‘0’

PIC18F1230/1330

10.4 IPR Registers

The IPR registers contain the individual priority bits for

the peripheral interrupts. Due to the number of

peripheral interrupt sources, there are three Peripheral

Interrupt Priority registers (IPR1, IPR2 and IPR3). Using

the priority bits requires that the Interrupt Priority Enable

(IPEN) bit be set.

U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1

— ADIP RCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 Unimplemented: Read as ‘0’

bit 6 ADIP: A/D Converter Interrupt Priority bit

1 = High priority

0 = Low priority

bit 5 RCIP: EUSART Receive Interrupt Priority bit

1 = High priority

0 = Low priority

bit 4 TXIP: EUSART Transmit Interrupt Priority bit

1 = High priority

0 = Low priority

bit 3 CMP2IP: Analog Comparator 2 Interrupt Priority bit

1 = CMP2 is high priority

0 = CMP2 is low priority

bit 2 CMP1IP: Analog Comparator 1 Interrupt Priority bit

1 = CMP1 is high priority

0 = CMP1 is low priority

bit 1 CMP0IP: Analog Comparator 0 Interrupt Priority bit

1 = CMP0 is high priority

0 = CMP0 is low priority

bit 0 TMR1IP: TMR1 Overflow Interrupt Priority bit

1 = High priority

0 = Low priority

PIC18F1230/1330

R/W-1 U-0 U-0 R/W-1 U-0 R/W-1 U-0 U-0

OSCFIP —— EEIP —LVDIP — —

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 OSCFIP: Oscillator Fail Interrupt Priority bit

1 = High priority

0 = Low priority

bit 6-5 Unimplemented: Read as ‘0’

bit 4 EEIP: Data EEPROM/Flash Write Operation Interrupt Priority bit

1 = High priority

0 = Low priority

bit 3 Unimplemented: Read as ‘0’

bit 2 LVDIP: Low-Voltage Detect Interrupt Priority bit

1 = High priority

0 = Low priority

bit 1-0 Unimplemented: Read as ‘0’

U-0 U-0 U-0 R/W-1 U-0 U-0 U-0 U-0

— — —PTIP— — — —

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-5 Unimplemented: Read as ‘0’

bit 4 PTIP: PWM Time Base Interrupt Priority bit

1 = High priority

0 = Low priority

bit 3-0 Unimplemented: Read as ‘0’

PIC18F1230/1330
DS39758C-page 98 Advance Information © 2007 Microchip Technology Inc.
10.5 RCON Register
The RCON register contains flag bits which are used to
determine the cause of the last Reset or wake-up from
Idle or Sleep modes. RCON also contains the IPEN bit
which enables interrupt priorities.
The operation of the SBOREN bit and the Reset flag
bits is discussed in more detail in Section 4.1 “RCON
Register”.
              
REGISTER 10-13: RCON: RESET CONTROL REGISTER
R/W-0 R/W-1(1) U-0 R/W-1 R-1 R-1 R/W-0(2) R/W-0
IPEN SBOREN —RITO PD POR BOR
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IPEN: Interrupt Priority Enable bit 
1 = Enable priority levels on interrupts
0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode)
bit 6 SBOREN: BOR Software Enable bit(1) 
For details of bit operation, see Register 4-1.
bit 5 Unimplemented: Read as ‘0’
bit 4 RI: RESET Instruction Flag bit
For details of bit operation, see Register 4-1.
bit 3 TO: Watchdog Time-out Flag bit 
For details of bit operation, see Register 4-1.
bit 2 PD: Power-Down Detection Flag bit 
For details of bit operation, see Register 4-1.
bit 1 POR: Power-on Reset Status bit(2) 
For details of bit operation, see Register 4-1.
bit 0 BOR: Brown-out Reset Status bit
For details of bit operation, see Register 4-1.
Note 1: If SBOREN is enabled, its Reset state is ‘1’; otherwise, it is ‘0’. See Register 4-1 for additional information.
2: The actual Reset value of POR is determined by the type of device Reset. See Register 4-1 for additional 
information.

PIC18F1230/1330

10.6 INTx Pin Interrupts

External interrupts on the RA0/INT0, RA1/INT1, RB2/

INT2 and RB3/INT3 pins are edge-triggered. If the

corresponding INTEDGx bit in the INTCON2 register is

set (= 1), the interrupt is triggered by a rising edge; if

the bit is clear, the trigger is on the falling edge. When

a valid edge appears on the pin, the corresponding flag

bit, INTxIF, is set. This interrupt can be disabled by

clearing the corresponding enable bit, INTxIE. Flag bit,

INTxIF, must be cleared in software in the Interrupt

Service Routine before re-enabling the interrupt.

All external interrupts (INT0, INT1, INT2 and INT3) can

wake-up the processor from Idle or Sleep modes if bit

INTxIE was set prior to going into those modes. If the

Global Interrupt Enable bit, GIE, is set, the processor

will branch to the interrupt vector following wake-up.

Interrupt priority for INT1, INT2 and INT3 is determined

by the value contained in the interrupt priority bits,

INT1IP (INTCON3<6>), INT2IP (INTCON3<7>) and

INT3IP (INTCON2<1>). There is no priority bit

associated with INT0. It is always a high-priority

interrupt source.

10.7 TMR0 Interrupt

In 8-bit mode (which is the default), an overflow in the

TMR0 register (FFh →00h) will set flag bit, TMR0IF. In

16-bit mode, an overflow in the TMR0H:TMR0L

interrupt can be enabled/disabled by setting/clearing

enable bit, TMR0IE (INTCON<5>). Interrupt priority for

Timer0 is determined by the value contained in the

interrupt priority bit, TMR0IP (INTCON2<2>). See

Section 11.0 “Timer0 Module” for further details on

the Timer0 module.

10.8 Interrupt-on-Change

An input change on PORTA<1:0> and/or PORTB<2:3>

sets flag bit, RBIF (INTCON<0>). The interrupt can be

enabled/disabled by setting/clearing enable bit, RBIE

(INTCON<3>). Interrupt priority for interrupt-on-change

is determined by the value contained in the interrupt

priority bit, RBIP (INTCON2<0>).

10.9 Context Saving During Interrupts

During interrupts, the return PC address is saved on

the stack. Additionally, the WREG, STATUS and BSR

registers are saved on the fast return stack. If a fast

return from interrupt is not used (see Section 5.3

“Data Memory Organization”), the user may need to

save the WREG, STATUS and BSR registers on entry

to the Interrupt Service Routine. Depending on the

user’s application, other registers may also need to be

saved. Example 10-1 saves and restores the WREG,

STATUS and BSR registers during an Interrupt Service

Routine.

EXAMPLE 10-1: SAVING STATUS, WREG AND BSR REGISTERS IN RAM

MOVWF W_TEMP ; W_TEMP is in virtual bank

MOVFF STATUS, STATUS_TEMP ; STATUS_TEMP located anywhere

MOVFF BSR, BSR_TEMP ; BSR_TMEP located anywhere

;

; USER ISR CODE

;

MOVFF BSR_TEMP, BSR ; Restore BSR

MOVF W_TEMP, W ; Restore WREG

MOVFF STATUS_TEMP, STATUS ; Restore STATUS

PIC18F1230/1330

NOTES:

PIC18F1230/1330

11.0 TIMER0 MODULE

The Timer0 module has the following features:

• Software selectable as an 8-bit or

16-bit timer/counter

• Readable and writable

• Dedicated 8-bit software programmable prescaler

• Clock source selectable to be external or internal

• Interrupt on overflow from FFh to 00h in 8-bit

mode and FFFFh to 0000h in 16-bit mode

• Edge select for external clock

Figure 11-1 shows a simplified block diagram of the

Timer0 module in 8-bit mode and Figure 11-2 shows a

simplified block diagram of the Timer0 module in 16-bit

mode.

The T0CON register (Register 11-1) is a readable and

writable register that controls all the aspects of Timer0,

including the prescale selection.

R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1

TMR0ON T016BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 TMR0ON: Timer0 On/Off Control bit

1 = Enables Timer0

0 = Stops Timer0

bit 6 T016BIT: Timer0 16-Bit Control bit

1 = Timer0 is configured as an 8-bit timer/counter

0 = Timer0 is configured as a 16-bit timer/counter

bit 5 T0CS: Timer0 Clock Source Select bit

1 = Transition on T0CKI pin

0 = Internal instruction cycle clock (CLKO)

bit 4 T0SE: Timer0 Source Edge Select bit

1 = Increment on high-to-low transition on T0CKI pin

0 = Increment on low-to-high transition on T0CKI pin

bit 3 PSA: Timer0 Prescaler Assignment bit

1 = TImer0 prescaler is NOT assigned. Timer0 clock input bypasses prescaler.

0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output.

bit 2-0 T0PS2:T0PS0: Timer0 Prescaler Select bits

111 = 1:256 Prescale value

110 = 1:128 Prescale value

101 = 1:64 Prescale value

100 = 1:32 Prescale value

011 = 1:16 Prescale value

010 = 1:8 Prescale value

001 = 1:4 Prescale value

000 = 1:2 Prescale value

PIC18F1230/1330

FIGURE 11-1: TIMER0 BLOCK DIAGRAM IN 8-BIT MODE

FIGURE 11-2: TIMER0 BLOCK DIAGRAM IN 16-BIT MODE

Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale.

T0CKI pin

T0SE

T0CS

FOSC/4

Programmable

Prescaler

TMR0

(2 TCY Delay)

Data Bus

PSA

T0PS2, T0PS1, T0PS0 Set Interrupt

Flag bit TMR0IF

on Overflow

Sync with

Internal

Clocks

Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale.

T0SE

T0CS

FOSC/4

Programmable

Prescaler

Sync with

Internal

Clocks TMR0L

(2 TCY Delay)

Data Bus<7:0>

PSA

T0PS2, T0PS1, T0PS0

Set Interrupt

Flag bit TMR0IF

on Overflow

TMR0

TMR0H

High Byte

Read TMR0L

Write TMR0L

T0CKI pin

PIC18F1230/1330

11.1 Timer0 Operation

Timer0 can operate as a timer or as a counter.

Timer mode is selected by clearing the T0CS bit. In

Timer mode, the Timer0 module will increment every

instruction cycle (without prescaler). If the TMR0

following two instruction cycles. The user can work

around this by writing an adjusted value to the TMR0

Counter mode is selected by setting the T0CS bit. In

Counter mode, Timer0 will increment, either on every

rising or falling edge of pin RA4/T0CKI/AN2/VREF+.

The incrementing edge is determined by the Timer0

Source Edge Select bit (T0SE). Clearing the T0SE bit

selects the rising edge.

When an external clock input is used for Timer0, it must

meet certain requirements. The requirements ensure

the external clock can be synchronized with the internal

phase clock (TOSC). Also, there is a delay in the actual

incrementing of Timer0 after synchronization.

11.2 Prescaler

An 8-bit counter is available as a prescaler for the Timer0

module. The prescaler is not readable or writable.

The PSA and T0PS2:T0PS0 bits determine the

prescaler assignment and prescale ratio.

Clearing bit PSA will assign the prescaler to the Timer0

module. When the prescaler is assigned to the Timer0

module, prescale values of 1:2, 1:4, ..., 1:256 are

selectable.

When assigned to the Timer0 module, all instructions writ-

ing to the TMR0 register (e.g., CLRF TMR0, MOVWF TMR0,

BSF TMR0, x..., etc.) will clear the prescaler count.

11.2.1 SWITCHING PRESCALER

ASSIGNMENT

The prescaler assignment is fully under software

control (i.e., it can be changed “on-the-fly” during

program execution).

11.3 Timer0 Interrupt

The TMR0 interrupt is generated when the TMR0

FFFFh to 0000h in 16-bit mode. This overflow sets the

TMR0IF bit. The interrupt can be masked by clearing

the TMR0IE bit. The TMR0IF bit must be cleared in

software by the Timer0 module Interrupt Service

Routine before re-enabling this interrupt. The TMR0

interrupt cannot awaken the processor from Sleep

mode, since the timer requires clock cycles even when

T0CS is set.

11.4 16-Bit Mode Timer Reads and

Writes

TMR0H is not the high byte of the timer/counter in

16-bit mode, but is actually a buffered version of the

high byte of Timer0 (refer to Figure 11-2). The high byte

of the Timer0 counter/timer is not directly readable nor

writable. TMR0H is updated with the contents of the

high byte of Timer0 during a read of TMR0L. This

provides the ability to read all 16 bits of Timer0 without

having to verify that the read of the high and low byte

were valid due to a rollover between successive reads

of the high and low byte.

A write to the high byte of Timer0 must also take place

through the TMR0H Buffer register. Timer0 high byte is

updated with the contents of TMR0H when a write

occurs to TMR0L. This allows all 16 bits of Timer0 to be

updated at once.

TABLE 11-1: REGISTERS ASSOCIATED WITH TIMER0

Note: Writing to TMR0, when the prescaler is

assigned to Timer0, will clear the

prescaler count but will not change the

prescaler assignment.

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Reset

Values on

Page:

TMR0L Timer0 Register Low Byte 42

TMR0H Timer0 Register High Byte 42

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41

T0CON TMR0ON T016BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 42

TRISA RA7(1) RA6(1) PORTA Data Direction Control Register 43

Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used by Timer0.

Note 1: RA6 and RA7 are enabled as I/O pins depending on the oscillator mode selected in CONFIG1H.

PIC18F1230/1330

NOTES:

PIC18F1230/1330

12.0 TIMER1 MODULE

The Timer1 timer/counter module has the following

features:

• 16-bit timer/counter

(two 8-bit registers; TMR1H and TMR1L)

• Readable and writable (both registers)

• Internal or external clock select

• Interrupt on overflow from FFFFh to 0000h

• Status of system clock operation

Figure 12-1 is a simplified block diagram of the Timer1

module.

module and contains the Timer1 Oscillator Enable bit

(T1OSCEN). Timer1 can be enabled or disabled by

setting or clearing control bit, TMR1ON (T1CON<0>).

The Timer1 oscillator can be used as a secondary clock

source in power-managed modes. When the T1RUN bit

is set, the Timer1 oscillator provides the system clock. If

the Fail-Safe Clock Monitor is enabled and the Timer1

oscillator fails while providing the system clock, polling

the T1RUN bit will indicate whether the clock is being

provided by the Timer1 oscillator or another source.

Timer1 can also be used to provide Real-Time Clock

(RTC) functionality to applications with only a minimal

addition of external components and code overhead.

R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 RD16: 16-Bit Read/Write Mode Enable bit

1 = Enables register read/write of Timer1 in one 16-bit operation

0 = Enables register read/write of Timer1 in two 8-bit operations

bit 6 T1RUN: Timer1 System Clock Status bit

1 = Device clock is derived from Timer1 oscillator

0 = Device clock is derived from another source

bit 5-4 T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits

11 = 1:8 Prescale value

10 = 1:4 Prescale value

01 = 1:2 Prescale value

00 = 1:1 Prescale value

bit 3 T1OSCEN: Timer1 Oscillator Enable bit

1 = Timer1 oscillator is enabled

0 = Timer1 oscillator is shut off

The oscillator inverter and feedback resistor are turned off to eliminate power drain.

bit 2 T1SYNC: Timer1 External Clock Input Synchronization Select bit

When TMR1CS = 1:

1 = Do not synchronize external clock input

0 = Synchronize external clock input

When TMR1CS = 0:

This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.

bit 1 TMR1CS: Timer1 Clock Source Select bit

1 = External clock from T1OSO/T1CKI (on the rising edge)(1)

0 = Internal clock (FOSC/4)

bit 0 TMR1ON: Timer1 On bit

1 = Enables Timer1

0 = Stops Timer1

Note 1: Placement of T1OSI and T1OSO/T1CKI depends on the value of the Configuration bit, T1OSCMX, of CONFIG3H.

PIC18F1230/1330

12.1 Timer1 Operation

Timer1 can operate in one of these modes:

•As a timer

• As a synchronous counter

• As an asynchronous counter

The operating mode is determined by the Clock Select

bit, TMR1CS (T1CON<1>).

When TMR1CS = 0, Timer1 increments every

instruction cycle. When TMR1CS = 1, Timer1

increments on every rising edge of the external clock

input or the Timer1 oscillator, if enabled.

When the Timer1 oscillator is enabled (T1OSCEN is

set), the T1OSI and T1OSO/T1CKI pins become

inputs. That is, the corresponding TRISA bit value is

ignored, and the pins are read as ‘0’.

FIGURE 12-1: TIMER1 BLOCK DIAGRAM

FIGURE 12-2: TIMER1 BLOCK DIAGRAM: 16-BIT READ/WRITE MODE

T1OSC

TMR1H TMR1L

T1SYNC

TMR1CS

T1CKPS1:T1CKPS0 Peripheral Clocks

FOSC/4

Internal

Clock

TMR1ON

On/Off

Synchronize

det

Synchronized

Clock Input

TMR1IF

Overflow TMR1

T1OSCEN

Enable

Oscillator(1)

Interrupt

Flag Bit

Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.

T1OSI

T1OSO/T1CKI

Prescaler

1, 2, 4, 8

Timer1 TMR1L

T1OSC

T1SYNC

TMR1CS

T1CKPS1:T1CKPS0

Peripheral Clocks

T1OSCEN

Enable

Oscillator(1)

TMR1IF

Overflow

Interrupt

FOSC/4

Internal

Clock

TMR1ON

On/Off

Prescaler

1, 2, 4, 8

Synchronize

det

Synchronized

Clock Input

T1OSO/T1CKI

T1OSI

TMR1

Flag bit

Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.

High Byte

Data Bus<7:0>

TMR1H

Read TMR1L

Write TMR1L

PIC18F1230/1330

12.2 Timer1 Oscillator

A crystal oscillator circuit is built-in between pins T1OSI

(input) and T1OSO/TICKI (amplifier output). The place-

ment of these pins depends on the value of Configuration

bit, T1OSCMX (see Section 19.1 “Configuration

Bits”). It is enabled by setting control bit T1OSCEN

(T1CON<3>). The oscillator is a low-power oscillator

rated for 32 kHz crystals. It will continue to run during all

power-managed modes. The circuit for a typical LP

oscillator is shown in Figure 12-3. Table 12-1 shows the

capacitor selection for the Timer1 oscillator.

The user must provide a software time delay to ensure

proper start-up of the Timer1 oscillator.

FIGURE 12-3: EXTERNAL

COMPONENTS FOR THE

TIMER1 LP OSCILLATOR

TABLE 12-1: CAPACITOR SELECTION FOR

THE TIMER OSCILLATOR

12.2.1 USING TIMER1 AS A CLOCK

SOURCE

The Timer1 oscillator is also available as a clock source

in power-managed modes. By setting the System

Clock Select bits, SCS1:SCS0 (OSCCON<1:0>), to

‘01’, the device switches to SEC_RUN mode; both the

CPU and peripherals are clocked from the Timer1 oscil-

lator. If the IDLEN bit (OSCCON<7>) is cleared and a

SLEEP instruction is executed, the device enters

SEC_IDLE mode. Additional details are available in

Section 3.0 “Power-Managed Modes”.

Whenever the Timer1 oscillator is providing the clock

source, the Timer1 system clock status flag, T1RUN

(T1CON<6>), is set. This can be used to determine the

controller’s current clocking mode. It can also indicate

the clock source being currently used by the Fail-Safe

Clock Monitor. If the Clock Monitor is enabled and the

Timer1 oscillator fails while providing the clock, polling

the T1RUN bit will indicate whether the clock is being

provided by the Timer1 oscillator or another source.

12.3 Timer1 Oscillator Layout

Considerations

The oscillator circuit, shown in Figure 12-3, should be

located as close as possible to the microcontroller.

There should be no circuits passing within the oscillator

circuit boundaries other than VSS or VDD.

If a high-speed circuit must be located near the

oscillator (such as the PWM pin, or the primary

oscillator using the OSC2 pin), a grounded guard ring

around the oscillator circuit, as shown in Figure 12-4,

may be helpful when used on a single-sided PCB, or in

addition to a ground plane.

FIGURE 12-4: OSCILLATOR CIRCUIT

WITH GROUNDED GUARD

RING

Osc Type Freq C1 C2

LP 32 kHz 27 pF(1) 27 pF(1)

Note 1: Microchip suggests this value as a starting

point in validating the oscillator circuit.

2: Higher capacitance increases the stability

of the oscillator, but also increases the

start-up time.

3: Since each resonator/crystal has its own

characteristics, the user should consult

the resonator/crystal manufacturer for

appropriate values of external

components.

4: Capacitor values are for design guidance

only.

Note: See the notes with Table 12-1 for addi-

tional information about capacitor selec-

XTAL

PIC18FXXXX

T1OSI

T1OSO/T1CKI

32.768 kHz

33 pF

RB3

RB2

OSC1

OSC2

VDD

Note: Not drawn to scale.

PIC18F1230/1330

12.4 Timer1 Interrupt

The TMR1 register pair (TMR1H:TMR1L) increments

from 0000h to FFFFh and rolls over to 0000h. The

Timer1 interrupt, if enabled, is generated on overflow

which is latched in interrupt flag bit, TMR1IF

(PIR1<0>). This interrupt can be enabled/disabled by

setting/clearing Timer1 interrupt enable bit, TMR1IE

(PIE1<0>).

12.5 Timer1 16-Bit Read/Write Mode

Timer1 can be configured for 16-bit reads and writes

(see Figure 12-2). When the RD16 control bit

(T1CON<7>) is set, the address for TMR1H is mapped

to a buffer register for the high byte of Timer1. A read

from TMR1L will load the contents of the high byte of

Timer1 into the Timer1 High Byte Buffer register. This

provides the user with the ability to accurately read all

16 bits of Timer1 without having to determine whether

a read of the high byte, followed by a read of the low

byte, is valid due to a rollover between reads.

A write to the high byte of Timer1 must also take place

through the TMR1H Buffer register. Timer1 high byte is

updated with the contents of TMR1H when a write

occurs to TMR1L. This allows a user to write all 16 bits

to both the high and low bytes of Timer1 at once.

The high byte of Timer1 is not directly readable or

writable in this mode. All reads and writes must take

place through the Timer1 High Byte Buffer register.

Writes to TMR1H do not clear the Timer1 prescaler.

The prescaler is only cleared on writes to TMR1L.

12.6 Using Timer1 as a Real-Time Clock

Adding an external LP oscillator to Timer1 (such as the

one described in Section 12.2 “Timer1 Oscillator”),

gives users the option to include RTC functionality to

their applications. This is accomplished with an

inexpensive watch crystal to provide an accurate time

base and several lines of application code to calculate

the time. When operating in Sleep mode and using a

battery or super capacitor as a power source, it can

completely eliminate the need for a separate RTC

device and battery backup.

The application code routine, RTCisr, shown in

Example 12-1, demonstrates a simple method to

increment a counter at one-second intervals using an

Interrupt Service Routine. Incrementing the TMR1

the routine, which increments the seconds counter by

one. Additional counters for minutes and hours are

incremented as the previous counter overflow.

Since the register pair is 16 bits wide, counting up to

overflow the register directly from a 32.768 kHz clock

would take 2 seconds. To force the overflow at the

required one-second intervals, it is necessary to pre-

load it. The simplest method is to set the MSb of

TMR1H with a BSF instruction. Note that the TMR1L

introduce cumulative error over many cycles.

For this method to be accurate, Timer1 must operate in

Asynchronous mode and the Timer1 overflow interrupt

must be enabled (PIE1<0> = 1), as shown in the

routine, RTCinit. The Timer1 oscillator must also be

enabled and running at all times.

PIC18F1230/1330

EXAMPLE 12-1: IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE

TABLE 12-2: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER

RTCinit

MOVLW 0x80 ; Preload TMR1 register pair

MOVWF TMR1H ; for 1 second overflow

CLRF TMR1L

MOVLW b’00001111’ ; Configure for external clock,

MOVWF T1OSC ; Asynchronous operation, external oscillator

CLRF secs ; Initialize timekeeping registers

CLRF mins ;

MOVLW .12

MOVWF hours

BSF PIE1, TMR1IE ; Enable Timer1 interrupt

RETURN

RTCisr

BSF TMR1H, 7 ; Preload for 1 sec overflow

BCF PIR1, TMR1IF ; Clear interrupt flag

INCF secs, F ; Increment seconds

MOVLW .59 ; 60 seconds elapsed?

CPFSGT secs

RETURN ; No, done

CLRF secs ; Clear seconds

INCF mins, F ; Increment minutes

MOVLW .59 ; 60 minutes elapsed?

CPFSGT mins

RETURN ; No, done

CLRF mins ; clear minutes

INCF hours, F ; Increment hours

MOVLW .23 ; 24 hours elapsed?

CPFSGT hours

RETURN ; No, done

MOVLW .01 ; Reset hours to 1

MOVWF hours

RETURN ; Done

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Reset

Values on

Page:

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41

PIR1 —ADIF RCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF 43

PIE1 —ADIE RCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE 43

IPR1 —ADIP RCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP 43

TMR1L Timer1 Register Low Byte 42

TMR1H Timer1 Register High Byte 42

T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 42

Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer1 module.

PIC18F1230/1330

NOTES:

PIC18F1230/1330

13.0 POWER CONTROL PWM

MODULE

The Power Control PWM module simplifies the task of

generating multiple, synchronized Pulse-Width

Modulated (PWM) outputs for use in the control of

motor controllers and power conversion applications.

In particular, the following power and motion control

applications are supported by the PWM module:

• Three-Phase and Single-Phase AC Induction

Motors

• Switched Reluctance Motors

• Brushless DC (BLDC) Motors

• Uninterruptible Power Supplies (UPS)

• Multiple DC Brush Motors

The PWM module has the following features:

• Up to six PWM I/O pins with three duty cycle

generators. Pins can be paired to acquire a

complete half-bridge control.

• Up to 14-bit resolution, depending upon the PWM

period.

• “On-the-fly” PWM frequency changes.

• Edge and Center-Aligned Output modes.

• Single-Pulse Generation mode.

• Programmable dead-time control between paired

PWMs.

• Interrupt support for asymmetrical updates in

Center-Aligned mode.

• Output override for Electrically Commutated Motor

(ECM) operation; for example, BLDC.

• Special Event Trigger comparator for triggering A/D

conversion.

• PWM outputs disable feature sets PWM outputs to

their inactive state when in Debug mode.

The Power Control PWM module supports three PWM

generators and six output channels on PIC18F1230/

1330 devices. A simplified block diagram of the module

is shown in Figure 13-1. Figure 13-2 and Figure 13-3

show how the module hardware is configured for each

PWM output pair for the Complementary and

Independent Output modes.

Each functional unit of the PWM module will be

discussed in subsequent sections.

PIC18F1230/1330

FIGURE 13-1: POWER CONTROL PWM MODULE BLOCK DIAGRAM

PDC2

PDC2 Buffer

Output

Driver

Block

PWMCON0

PTPER Buffer

PWMCON1

PTPER

PTMR

Comparator

Channel 2

PTCONx

SEVTCMP

Comparator Special Event Trigger

OVDCON<D/S>

PWM Enable and Mode

PWM Manual Control

PWM

PWM Generator #2(1)

SEVTDIR

PTDIR

DTCON Dead-Time Control

Special Event

Postscaler

FLTA

PWM0

PWM1

PWM2

PWM3

Note 1: Only PWM Generator 2 is shown in detail. The other generators are identical; their details are omitted for clarity.

PWM4

PWM5

FLTCONFIG Fault Pin Control

Dead-Time Generator

and Override Logic(1)

Channel 1

Dead-Time Generator

and Override Logic

Channel 0

Dead-Time Generator

and Override Logic

Internal Data Bus

Generator 0

Generator 1

PIC18F1230/1330

FIGURE 13-2: PWM MODULE BLOCK DIAGRAM, ONE OUTPUT PAIR, COMPLEMENTARY MODE

FIGURE 13-3: PWM MODULE BLOCK DIAGRAM, ONE OUTPUT PAIR, INDEPENDENT MODE

This module contains three duty cycle generators,

numbered 0 through 2. The module has six PWM

output pins, numbered 0 through 5. The six PWM

outputs are grouped into output pairs of even and odd

numbered outputs. In Complementary modes, the

even PWM pins must always be the complement of the

corresponding odd PWM pins. For example, PWM0 will

be the complement of PWM1 and PWM2 will be the

complement of PWM3. The dead-time generator

inserts an OFF period called “dead time” between the

going OFF of one pin to the going ON of the

complementary pin of the paired pins. This is to prevent

damage to the power switching devices that will be

connected to the PWM output pins.

The time base for the PWM module is provided by its

own 12-bit timer, which also incorporates selectable

prescaler and postscaler options.

PWM Duty Cycle Register

Duty Cycle Comparator

Dead-Band

Generator

Fault Override Values

Channel Override Values

Fault Pin Assignment

Logic

Fault A pin

HPOL

LPOL

PWM1

PWM0

VDD

Note: In the Complementary mode, the even channel cannot be forced active by a Fault or override event when the odd channel is

active. The even channel is always the complement of the odd channel and is inactive, with dead time inserted, before the odd

channel is driven to its active state.

Duty Cycle Comparator

PWM Duty Cycle Register

Fault A pin

HPOL

LPOL

PWM1

PWM0

VDD

Fault Override Values

Channel Override Values

Fault Pin Assignment

Logic

PIC18F1230/1330

13.1 Control Registers

The operation of the PWM module is controlled by a

total of 20 registers. Eight of these are used to

configure the features of the module:

• PWM Timer Control Register 0 (PTCON0)

• PWM Timer Control Register 1 (PTCON1)

• PWM Control Register 0 (PWMCON0)

• PWM Control Register 1 (PWMCON1)

• Dead-Time Control Register (DTCON)

• Output Override Control Register (OVDCOND)

• Output State Register (OVDCONS)

• Fault Configuration Register (FLTCONFIG)

There are also 12 registers that are configured as six

configuration values of specific features. They are:

• PWM Time Base Registers (PTMRH and PTMRL)

• PWM Time Base Period Registers (PTPERH and

PTPERL)

• PWM Special Event Compare Registers

(SEVTCMPH and SEVTCMPL)

• PWM Duty Cycle #0 Registers

(PDC0H and PDC0L)

• PWM Duty Cycle #1 Registers

(PDC1H and PDC1L)

• PWM Duty Cycle #2 Registers

(PDC2H and PDC2L)

All of these register pairs are double-buffered.

13.2 Module Functionality

The PWM module supports several modes of operation

that are beneficial for specific power and motor control

applications. Each mode of operation is described in

subsequent sections.

The PWM module is composed of several functional

blocks. The operation of each is explained separately

in relation to the several modes of operation:

•PWM Time Base

• PWM Time Base Interrupts

•PWM Period

• PWM Duty Cycle

• Dead-Time Generators

• PWM Output Overrides

• PWM Fault Inputs

• PWM Special Event Trigger

13.3 PWM Time Base

The PWM time base is provided by a 12-bit timer with

prescaler and postscaler functions. A simplified block

diagram of the PWM time base is shown in Figure 13-4.

The PWM time base is configured through the PTCON0

and PTCON1 registers. The time base is enabled or

disabled by respectively setting or clearing the PTEN bit

in the PTCON1 register.

Note: The PTMR register pair (PTMRL:PTMRH)

is not cleared when the PTEN bit is

cleared in software.

PIC18F1230/1330

FIGURE 13-4: PWM TIME BASE BLOCK DIAGRAM

The PWM time base can be configured for four different

modes of operation:

• Free-Running mode

• Single-Shot mode

• Continuous Up/Down Count mode

• Continuous Up/Down Count mode with interrupts

for double updates

These four modes are selected by the

PTMOD1:PTMOD0 bits in the PTCON0 register. The

Free-Running mode produces edge-aligned PWM

generation. The Continuous Up/Down Count modes

produce center-aligned PWM generation. The Single-

Shot mode allows the PWM module to support pulse

control of certain Electronically Commutated Motors

(ECMs) and produces edge-aligned operation.

PTMR Register

PTPER

Comparator

PTPER Buffer

Comparator Zero Match

Period Match

PTMOD1

Up/Down

Timer Reset

FOSC/4 Prescaler

1:1, 1:4, 1:16, 1:64

Timer

Direction

Control

Clock

Control

Period Load

Duty Cycle Load

PTMOD1

Period Match

Zero Match

PTMR Clock

Interrupt

Control

PTMOD1

Period Match

Zero Match

PTMOD0

PTEN

PTIF

PTDIR

PTMR Clock

Update Disable (UDIS)

Postscaler

1:1-1:16

PIC18F1230/1330

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

PTOPS3 PTOPS2 PTOPS1 PTOPS0 PTCKPS1 PTCKPS0 PTMOD1 PTMOD0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-4 PTOPS3:PTOPS0: PWM Time Base Output Postscale Select bits

0000 = 1:1 Postscale

0001 = 1:2 Postscale

1111 = 1:16 Postscale

bit 3-2 PTCKPS1:PTCKPS0: PWM Time Base Input Clock Prescale Select bits

00 = PWM time base input clock is FOSC/4 (1:1 prescale)

01 = PWM time base input clock is FOSC/16 (1:4 prescale)

10 = PWM time base input clock is FOSC/64 (1:16 prescale)

11 = PWM time base input clock is FOSC/256 (1:64 prescale)

bit 1-0 PTMOD1:PTMOD0: PWM Time Base Mode Select bits

11 = PWM time base operates in a Continuous Up/Down Count mode with interrupts for double PWM

updates

10 = PWM time base operates in a Continuous Up/Down Count mode

01 = PWM time base configured for Single-Shot mode

00 = PWM time base operates in a Free-Running mode

R/W-0 R-0 U-0 U-0 U-0 U-0 U-0 U-0

PTEN PTDIR — — — — — —

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 PTEN: PWM Time Base Timer Enable bit

1 = PWM time base is on

0 = PWM time base is off

bit 6 PTDIR: PWM Time Base Count Direction Status bit

1 = PWM time base counts down

0 = PWM time base counts up

bit 5-0 Unimplemented: Read as ‘0’

PIC18F1230/1330

U-0 R/W-1(1) R/W-1(1) R/W-1(1) U-0 R/W-0 R/W-0 R/W-0

— PWMEN2 PWMEN1 PWMEN0 — PMOD2 PMOD1 PMOD0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 Unimplemented: Read as ‘0’

bit 6-4 PWMEN2:PWMEN0: PWM Module Enable bits(1)

111 = All odd PWM I/O pins enabled for PWM output

110 = PWM1, PWM3 pins enabled for PWM output

10x = All PWM I/O pins enabled for PWM output

011 = PWM0, PWM1, PWM2 and PWM3 I/O pins enabled for PWM output

010 = PWM0 and PWM1 pins enabled for PWM output

001 = PWM1 pin is enabled for PWM output

000 = PWM module disabled; all PWM I/O pins are general purpose I/O

bit 3 Unimplemented: Read as ‘0’

bit 2-0 PMOD2:PMOD0: PWM Output Pair Mode bits

For PMOD0:

1 = PWM I/O pin pair (PWM0, PWM1) is in the Independent mode

0 = PWM I/O pin pair (PWM0, PWM1) is in the Complementary mode

For PMOD1:

1 = PWM I/O pin pair (PWM2, PWM3) is in the Independent mode

0 = PWM I/O pin pair (PWM2, PWM3) is in the Complementary mode

For PMOD2:

1 = PWM I/O pin pair (PWM4, PWM5) is in the Independent mode

0 = PWM I/O pin pair (PWM4, PWM5) is in the Complementary mode

Note 1: Reset condition of PWMEN bits depends on the PWMPIN Configuration bit of CONFIG3L.

PIC18F1230/1330

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0

SEVOPS3 SEVOPS2 SEVOPS1 SEVOPS0 SEVTDIR — UDIS OSYNC

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-4 SEVOPS3:SEVOPS0: PWM Special Event Trigger Output Postscale Select bits

0000 = 1:1 Postscale

0001 = 1:2 Postscale

1111 = 1:16 Postscale

bit 3 SEVTDIR: Special Event Trigger Time Base Direction bit

1 = A Special Event Trigger will occur when the PWM time base is counting downwards

0 = A Special Event Trigger will occur when the PWM time base is counting upwards

bit 2 Unimplemented: Read as ‘0’

bit 1 UDIS: PWM Update Disable bit

1 = Updates from Duty Cycle and Period Buffer registers are disabled

0 = Updates from Duty Cycle and Period Buffer registers are enabled

bit 0 OSYNC: PWM Output Override Synchronization bit

1 = Output overrides via the OVDCON register are synchronized to the PWM time base

0 = Output overrides via the OVDCON register are asynchronous

PIC18F1230/1330

13.3.1 FREE-RUNNING MODE

In the Free-Running mode, the PWM time base

(PTMRL and PTMRH) will begin counting upwards until

the value in the PWM Time Base Period register,

PTPER (PTPERL and PTPERH), is matched. The

PTMR registers will be reset on the following input

clock edge and the time base will continue counting

upwards as long as the PTEN bit remains set.

13.3.2 SINGLE-SHOT MODE

In the Single-Shot mode, the PWM time base will begin

counting upwards when the PTEN bit is set. When the

value in the PTMR register matches the PTPER

following input clock edge and the PTEN bit will be

cleared by the hardware to halt the time base.

13.3.3 CONTINUOUS UP/DOWN COUNT

MODES

In Continuous Up/Down Count modes, the PWM time

base counts upwards until the value in the PTPER

input clock edge, the timer counts downwards. The

PTDIR bit in the PTCON1 register is read-only and

indicates the counting direction. The PTDIR bit is set

when the timer counts downwards.

13.3.4 PWM TIME BASE PRESCALER

The input clock to PTMR (FOSC/4) has prescaler

options of 1:1, 1:4, 1:16 or 1:64. These are selected by

control bits, PTCKPS<1:0>, in the PTCON0 register.

The prescaler counter is cleared when any of the

following occurs:

• Write to the PTMR register

• Write to the PTCON (PTCON0 or PTCON1) register

• Any device Reset

Table 13-1 shows the minimum PWM frequencies that

can be generated with the PWM time base and the

prescaler. An operating frequency of 40 MHz

(FCYC = 10 MHz) and PTPER = 0xFFF are assumed in

the table. The PWM module must be capable of

generating PWM signals at the line frequency (50 Hz or

60 Hz) for certain power control applications.

TABLE 13-1: MINIMUM PWM FREQUENCY

13.3.5 PWM TIME BASE POSTSCALER

The match output of PTMR can optionally be

postscaled through a 4-bit postscaler (which gives a

1:1 to 1:16 scaling inclusive) to generate an interrupt.

The postscaler counter is cleared when any of the

following occurs:

• Write to the PTMR register

• Write to the PTCONx register

• Any device Reset

The PTMR register is not cleared when PTCONx is

written.

13.4 PWM Time Base Interrupts

The PWM timer can generate interrupts based on the

modes of operation selected by the PTMOD<1:0> bits

and the postscaler bits (PTOPS<3:0>).

13.4.1 INTERRUPTS IN FREE-RUNNING

MODE

When the PWM time base is in the Free-Running mode

(PTMOD<1:0> = 00), an interrupt event is generated

each time a match with the PTPER register occurs. The

PTMR register is reset to zero in the following clock

edge.

Using a postscaler selection other than 1:1 will reduce

the frequency of interrupt events.

Note: Since the PWM compare outputs are

driven to the active state when the PWM

time-base is counting downwards and

matches the duty cycle value, the PWM

outputs are held inactive during the first

half of the first period of the Continuous

Up/Down Count mode until the PTMR

begins to count down from the PTPER

value.

Note: The PTMR register is not cleared when

PTCONx is written.

Minimum PWM Frequencies vs. Prescaler Value

for FCYC = 10 MIPS (PTPER = 0FFFh)

Prescale

PWM

Frequency

Edge-Aligned

PWM

Frequency

Center-Aligned

1:1 2441 Hz 1221 Hz

1:4 610 Hz 305 Hz

1:16 153 Hz 76 Hz

1:64 38 Hz 19 Hz

PIC18F1230/1330

FIGURE 13-5: PWM TIME BASE INTERRUPT TIMING, FREE-RUNNING MODE

13.4.2 INTERRUPTS IN SINGLE-SHOT

MODE

When the PWM time base is in the Single-Shot mode

(PTMOD<1:0> = 01), an interrupt event is generated

when a match with the PTPER register occurs. The

PWM Time Base register (PTMR) is reset to zero on

the following input clock edge and the PTEN bit is

cleared. The postscaler selection bits have no effect in

this Timer mode.

13.4.3 INTERRUPTS IN CONTINUOUS

UP/DOWN COUNT MODE

In the Continuous Up/Down Count mode

(PTMOD<1:0> = 10), an interrupt event is generated

each time the value of the PTMR register becomes

zero and the PWM time base begins to count upwards.

The postscaler selection bits may be used in this Timer

mode to reduce the frequency of the interrupt events.

Figure 13-7 shows the interrupts in Continuous Up/

Down Count mode.

Q2Q1 Q3 Q4Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4

FOSC/4

PTMR_INT_REQ

FFEh FFFh 000h 001h 002h

PTIF bit

Note 1: PWM Time Base Period register, PTPER, is loaded with the value FFFh for this example.

QcQc Qc QcQcQc Qc Qc QcQc Qc Qc QcQc Qc Qc QcQc Qc Qc

PTIF bit

PTMR FFEh FFFh 001h 002h

A: PRESCALER = 1:1

B: PRESCALER = 1:4

PTMR

PTMR_INT_REQ

000h

PIC18F1230/1330

FIGURE 13-6: PWM TIME BASE INTERRUPT TIMING, SINGLE-SHOT MODE

FIGURE 13-7: PWM TIME BASE INTERRUPTS, CONTINUOUS UP/DOWN COUNT MODE

Q2Q1 Q3 Q4Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4

FOSC/4

PTMR FFEh FFFh 000h 000h 000h

PTIF bit

Note 1: Interrupt flag bit, PTIF, is sampled here (every Q1).

2: PWM Time Base Period register, PTPER, is loaded with the value FFFh for this example.

QcQc Qc QcQcQc Qc Qc QcQc Qc Qc QcQc Qc Qc QcQc Qc Qc

PTMR FFEh FFFh 000h 000h

A: PRESCALER = 1:1

B: PRESCALER = 1:4

PTMR_INT_REQ

Q4Q4

PTIF bit

PTMR_INT_REQ

000h

Q2Q1 Q3 Q4Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4

FOSC/4

PTMR 002h 001h 000h 001h 002h

Note 1: Interrupt flag bit, PTIF, is sampled here (every Q1).

QcQc Qc QcQcQc Qc Qc QcQc Qc Qc QcQc Qc Qc QcQc Qc Qc

PTMR 002h 001h 001h 002h

PTDIR bit

PRESCALER = 1:1

PRESCALER = 1:4

PTIF bit

PTMR_INT_REQ

PTDIR bit

Q4Q4

PTIF bit

PTMR_INT_REQ

11 1 1

000h

PIC18F1230/1330

13.4.4 INTERRUPTS IN DOUBLE UPDATE

MODE

This mode is available in Continuous Up/Down Count

mode. In the Double Update mode (PTMOD<1:0> = 11),

an interrupt event is generated each time the PTMR

matches the PTPER register. Figure 13-8 shows the

interrupts in Continuous Up/Down Count mode with

double updates.

The Double Update mode provides two additional

functions to the user in Center-Aligned mode.

1. The control loop bandwidth is doubled because

the PWM duty cycles can be updated twice per

period.

2. Asymmetrical center-aligned PWM waveforms

can be generated, which are useful for

minimizing output waveform distortion in certain

motor control applications.

FIGURE 13-8: PWM TIME BASE INTERRUPTS, CONTINUOUS UP/DOWN COUNT MODE WITH

DOUBLE UPDATES

Note: Do not change the PTMOD bits while

PTEN is active. It will yield unexpected

results. To change the PWM Timer mode

of operation, first clear the PTEN bit, load

PTMOD bits with required data and then

set PTEN.

Q2Q1 Q3 Q4Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4

OSC1

PTMR 3FDh 3FEh 3FFh 3FEh 3FDh

Case 1: PTMR Counting Upwards

Q2Q1 Q3 Q4Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4 Q2Q1 Q3 Q4

OSC1

PTMR 002h 001h 000h 001h 002h

Case 2: PTMR Counting Downwards

Note 1: Interrupt flag bit, PTIF, is sampled here (every Q1).

2: PWM Time Base Period register, PTPER, is loaded with the value 3FFh for this example.

PTIF bit

PTMR_INT_REQ

PTIF bit

PTMR_INT_REQ

A: PRESCALER = 1:1

PTDIR bit

PIC18F1230/1330

13.5 PWM Period

The PWM period is defined by the PTPER register pair

(PTPERL and PTPERH). The PWM period has 12-bit

resolution by combining 4 LSBs of PTPERH and 8 bits

of PTPERL. PTPER is a double-buffered register used

to set the counting period for the PWM time base.

The PTPER buffer contents are loaded into the PTPER

• Free-Running and Single-Shot modes: When the

PTMR register is reset to zero after a match with the

PTPER register.

• Continuous Up/Down Count modes: When the

PTMR register is zero. The value held in the PTPER

buffer is automatically loaded into the PTPER

(PTEN = 0). Figure 13-9 and Figure 13-10 indicate

the times when the contents of the PTPER buffer

are loaded into the actual PTPER register.

The PWM period can be calculated from the following

formulas:

EQUATION 13-1: PWM PERIOD FOR

FREE-RUNNING MODE

EQUATION 13-2: PWM PERIOD FOR

CONTINUOUS UP/DOWN

COUNT MODE

The PWM frequency is the inverse of period; or

EQUATION 13-3: PWM FREQUENCY

The maximum resolution (in bits) for a given device

oscillator and PWM frequency can be determined from

the following formula:

EQUATION 13-4: PWM RESOLUTION

The PWM resolutions and frequencies are shown for a

selection of execution speeds and PTPER values in

Table 13-2. The PWM frequencies in Table 13-2 are

calculated for Edge-Aligned PWM mode. For Center-

Aligned mode, the PWM frequencies will be

approximately one-half the values indicated in this

table.

TABLE 13-2: EXAMPLE PWM

FREQUENCIES AND

RESOLUTIONS

TPWM = (PTPER + 1) x PTMRPS

FOSC/4

TPWM = (2 x PTPER) x PTMRPS

FOSC

PWM Frequency = 1

PWM Period

PWM Frequency = 1/TPWM

FOSC MIPS PTPER

Value

PWM

Resolution

PWM

Frequency

40 MHz 10 0FFFh 14 bits 2.4 kHz

40 MHz 10 07FFh 13 bits 4.9 kHz

40 MHz 10 03FFh 12 bits 9.8 kHz

40 MHz 10 01FFh 11 bits 19.5 kHz

40 MHz 10 FFh 10 bits 39.0 kHz

40 MHz 10 7Fh 9 bits 78.1 kHz

40 MHz 10 3Fh 8 bits 156.2 kHz

40 MHz 10 1Fh 7 bits 312.5 kHz

40 MHz 10 0Fh 6 bits 625 kHz

25 MHz 6.25 0FFFh 14 bits 1.5 kHz

25 MHz 6.25 03FFh 12 bits 6.1 kHz

25 MHz 6.25 FFh 10 bits 24.4 kHz

10 MHz 2.5 0FFFh 14 bits 610 Hz

10 MHz 2.5 03FFh 12 bits 2.4 kHz

10 MHz 2.5 FFh 10 bits 9.8 kHz

5 MHz 1.25 0FFFh 14 bits 305 Hz

5 MHz 1.25 03FFh 12 bits 1.2 kHz

5 MHz 1.25 FFh 10 bits 4.9 kHz

4 MHz 1 0FFFh 14 bits 244 Hz

4 MHz 1 03FFh 12 bits 976 Hz

4 MHz 1 FFh 10 bits 3.9 kHz

Note: For center-aligned operation, PWM

frequencies will be approximately 1/2 the

value indicated in the table.

Resolution = log(2)

log FOSC

FPWM

PIC18F1230/1330

FIGURE 13-9: PWM PERIOD BUFFER UPDATES IN FREE-RUNNING MODE

FIGURE 13-10: PWM PERIOD BUFFER UPDATES IN CONTINUOUS UP/DOWN COUNT MODES

Old PTPER Value = 004

New PTPER Value = 007

Period Value Loaded from PTPER Buffer Register

New Value Written to PTPER Buffer

Old PTPER Value = 004

New PTPER Value = 007

Period Value Loaded from

PTPER Buffer Register

New Value Written to PTPER Buffer

PIC18F1230/1330

13.6 PWM Duty Cycle

PWM duty cycle is defined by the PDCx (PDCxL and

PDCxH) registers. There are a total of three PWM Duty

Cycle registers for four pairs of PWM channels. The

Duty Cycle registers have 14-bit resolution by combin-

ing the six LSbs of PDCxH with the 8 bits of PDCxL.

PDCx is a double-buffered register used to set the

counting period for the PWM time base.

13.6.1 PWM DUTY CYCLE REGISTERS

There are three 14-bit Special Function Registers used

to specify duty cycle values for the PWM module:

• PDC0 (PDC0L and PDC0H)

• PDC1 (PDC1L and PDC1H)

• PDC2 (PDC2L and PDC2H)

The value in each Duty Cycle register determines the

amount of time that the PWM output is in the active

state. The upper 12 bits of PDCx hold the actual duty

cycle value from PTMRH/L<11:0>, while the lower two

bits control which internal Q clock the duty cycle match

will occur. This 2-bit value is decoded from the Q

clocks, as shown in Figure 13-11, when the prescaler is

1:1 (PTCKPS<1:0> = 00).

In Edge-Aligned mode, the PWM period starts at Q1 and

ends when the Duty Cycle register matches the PTMR

when the upper 12 bits of the PDCx are equal to the

PTMR and the lower 2 bits are equal to Q1, Q2, Q3 or

Q4, depending on the lower two bits of the PDCx (when

the prescaler is 1:1 or PTCKPS<1:0> = 00).

Each compare unit has logic that allows override of the

PWM signals. This logic also ensures that the PWM

signals will complement each other (with dead-time

insertion) in Complementary mode (see Section 13.7

“Dead-Time Generators”).

FIGURE 13-11: DUTY CYCLE COMPARISON

Note: When the prescaler is not 1:1

(PTCKPS<1:0> ≠ ~00), the duty cycle

match occurs at the Q1 clock of the

instruction cycle when the PTMR and

PDCx match occurs.

Note: To get the correct PWM duty cycle, always

multiply the calculated PWM duty cycle

value by four before writing it to the PWM

Duty Cycle registers. This is due to the two

additional LSBs in the PWM Duty Cycle

registers which are compared against the

internal Q clock for the PWM duty cycle

match.

PTMR<11:0>

PDCx<13:0>

Comparator

Unused

PTMRH<7:0> PTMRL<7:0>

PTMRH<3:0> PTMRL<7:0> Q Clocks(1)

PDCxH<7:0> PDCxL<7:0>

PDCxH<5:0> PDCxL<7:0>

<1:0>

Note 1: This value is decoded from the Q clocks:

00 = duty cycle match occurs on Q1

01 = duty cycle match occurs on Q2

10 = duty cycle match occurs on Q3

11 = duty cycle match occurs on Q4

PIC18F1230/1330

13.6.2 DUTY CYCLE REGISTER BUFFERS

The three PWM Duty Cycle registers are double-

buffered to allow glitchless updates of the PWM

outputs. For each duty cycle block, there is a Duty

Cycle Buffer register that is accessible by the user and

a second Duty Cycle register that holds the actual

compare value used in the present PWM period.

In Edge-Aligned PWM Output mode, a new duty cycle

value will be updated whenever a PTMR match with the

PTPER register occurs and PTMR is reset, as shown in

Figure 13-12. Also, the contents of the duty cycle buffers

are automatically loaded into the Duty Cycle registers

when the PWM time base is disabled (PTEN = 0).

When the PWM time base is in the Continuous Up/

Down Count mode, new duty cycle values will be

updated when the value of the PTMR register is zero

and the PWM time base begins to count upwards. The

contents of the duty cycle buffers are automatically

loaded into the Duty Cycle registers when the PWM

time base is disabled (PTEN = 0). Figure 13-13 shows

the timings when the duty cycle update occurs for the

Continuous Up/Down Count mode. In this mode, up to

one entire PWM period is available for calculating and

loading the new PWM duty cycle before changes take

effect.

When the PWM time base is in the Continuous Up/

Down Count mode with double updates, new duty cycle

values will be updated when the value of the PTMR

contents of the duty cycle buffers are automatically

loaded into the Duty Cycle registers during both of the

previously described conditions. Figure 13-14 shows

the duty cycle updates for Continuous Up/Down Count

mode with double updates. In this mode, up to half of a

PWM period is available for calculating and loading the

new PWM duty cycle before changes take effect.

13.6.3 EDGE-ALIGNED PWM

Edge-aligned PWM signals are produced by the module

when the PWM time base is in the Free-Running mode

or the Single-Shot mode. For edge-aligned PWM

outputs, the output for a given PWM channel has a

period specified by the value loaded in PTPER and a

duty cycle specified by the appropriate Duty Cycle

active at the beginning of the period (PTMR = 0) and is

driven inactive when the value in the Duty Cycle register

matches PTMR. A new cycle is started when PTMR

matches the PTPER, as explained in the PWM period

section.

If the value in a particular Duty Cycle register is zero,

then the output on the corresponding PWM pin will be

inactive for the entire PWM period. In addition, the out-

put on the PWM pin will be active for the entire PWM

period if the value in the Duty Cycle register is greater

than the value held in the PTPER register.

FIGURE 13-12: EDGE-ALIGNED PWM

FIGURE 13-13: DUTY CYCLE UPDATE TIMES IN CONTINUOUS UP/DOWN COUNT MODE

Period

Duty Cycle

PTPER

PTMR

Value

New Duty Cycle Latched

Active at

of Period

Beginning

PDCx

(new)

(old)

PTMR Value

PWM Output

Duty Cycle Value Loaded from Buffer Register

New Value Written to Duty Cycle Buffer

PIC18F1230/1330

FIGURE 13-14: DUTY CYCLE UPDATE TIMES IN CONTINUOUS UP/DOWN COUNT MODE WITH

DOUBLE UPDATES

13.6.4 CENTER-ALIGNED PWM

Center-aligned PWM signals are produced by the

module when the PWM time base is configured in a

Continuous Up/Down Count mode (see Figure 13-15).

The PWM compare output is driven to the active state

when the value of the Duty Cycle register matches the

value of PTMR and the PWM time base is counting

downwards (PTDIR = 1). The PWM compare output

will be driven to the inactive state when the PWM time

base is counting upwards (PTDIR = 0) and the value in

the PTMR register matches the duty cycle value. If the

value in a particular Duty Cycle register is zero, then

the output on the corresponding PWM pin will be

inactive for the entire PWM period. In addition, the

output on the PWM pin will be active for the entire PWM

period if the value in the Duty Cycle register is equal to

or greater than the value in the PTPER register.

FIGURE 13-15: START OF CENTER-ALIGNED PWM

PTMR Value

PWM Output

Duty Cycle Value Loaded from Buffer Register

New Values Written to Duty Cycle Buffer

Note: When the PWM is started in Center-

Aligned mode, the PWM Time Base

Period register (PTPER) is loaded into the

PWM Time Base register (PTMR) and the

PTMR is configured automatically to start

down counting. This is done to ensure that

all the PWM signals don’t start at the same

time.

PTPER

PTMR

Value

Period

Period/2

Duty

Cycle

Start of

First

PWM

Period

Duty Cycle

PIC18F1230/1330

13.6.5 COMPLEMENTARY PWM

OPERATION

The Complementary mode of PWM operation is useful

to drive one or more power switches in half-bridge

configuration, as shown in Figure 13-16. This inverter

topology is typical for a 3-phase induction motor,

brushless DC motor or 3-phase Uninterruptible Power

Supply (UPS) control applications.

Each upper/lower power switch pair is fed by a

complementary PWM signal. Dead time may be

optionally inserted during device switching, where both

outputs are inactive for a short period (see

Section 13.7 “Dead-Time Generators”).

In Complementary mode, the duty cycle comparison

units are assigned to the PWM outputs as follows:

• PDC0 register controls PWM1/PWM0 outputs

• PDC1 register controls PWM3/PWM2 outputs

• PDC2 register controls PWM5/PWM4 outputs

PWM1/3/5 are the main PWMs that are controlled by

the PDCx registers and PWM0/2/4 are the

complemented outputs. When using the PWMs to

control the half-bridge, the odd number PWMs can be

used to control the upper power switch and the even

numbered PWMs can be used for the lower switches.

FIGURE 13-16: TYPICAL LOAD FOR

COMPLEMENTARY PWM

OUTPUTS

The Complementary mode is selected for each PWM

I/O pin pair by clearing the appropriate PMODx bit in

the PWMCON0 register. The PWM I/O pins are set to

Complementary mode by default upon all kinds of

device Resets.

PWM1

PWM0

PWM3

PWM2

PWM5

PWM4

3-Phase

Load

PIC18F1230/1330

13.7 Dead-Time Generators

In power inverter applications, where the PWMs are

used in Complementary mode to control the upper and

lower switches of a half-bridge, a dead-time insertion is

highly recommended. The dead-time insertion keeps

both outputs in inactive state for a brief time. This

avoids any overlap in the switching during the state

change of the power devices due to TON and TOFF

characteristics.

Because the power output devices cannot switch

instantaneously, some amount of time must be

provided between the turn-off event of one PWM output

in a complementary pair and the turn-on event of the

other transistor. The PWM module allows dead time to

be programmed. The following sections explain the

dead-time block in detail.

13.7.1 DEAD-TIME INSERTION

Each complementary output pair for the PWM module

has a 6-bit down counter used to produce the dead-

time insertion. As shown in Figure 13-17, each dead-

time unit has a rising and falling edge detector

connected to the duty cycle comparison output. The

dead time is loaded into the timer on the detected PWM

edge event. Depending on whether the edge is rising or

falling, one of the transitions on the complementary

outputs is delayed until the timer counts down to zero.

A timing diagram, indicating the dead-time insertion for

one pair of PWM outputs, is shown in Figure 13-18.

FIGURE 13-17: DEAD-TIME CONTROL UNIT BLOCK DIAGRAM FOR ONE PWM OUTPUT PAIR

FIGURE 13-18: DEAD-TIME INSERTION FOR COMPLEMENTARY PWM

Even PWM Signal to

Output Control Block

Odd PWM Signal to

Output Control Block

Zero Compare

Clock Control

and Prescaler 6-Bit Down Counter

Duty Cycle

Compare Input

Dead Time

Prescale

FOSC

Dead Time

Select Bits

Dead-Time Register

PDC1

Compare

Output

PWM1

PWM0

PIC18F1230/1330

13.7.2 DEAD-TIME RANGES

The amount of dead time provided by the dead-time

unit is selected by specifying the input clock prescaler

value and a 6-bit unsigned value defined in the DTCON

been provided to allow a suitable range of dead times

based on the device operating frequency. FOSC/2,

FOSC/4, FOSC/8 and FOSC/16 are the clock prescaler

options available using the DTPS1:DTPS0 control bits

in the DTCON register.

After selecting an appropriate prescaler value, the

dead time is adjusted by loading a 6-bit unsigned value

into DTCON<5:0>. The dead-time unit prescaler is

cleared on any of the following events:

• On a load of the down timer due to a duty cycle

comparison edge event;

• On a write to the DTCON register; or

• On any device Reset.

13.7.3 DECREMENTING THE DEAD-TIME

COUNTER

The dead-time counter is clocked from any of the

Q clocks based on the following conditions.

1. The dead-time counter is clocked on Q1 when:

• The DTPS bits are set to any of the following

dead-time prescaler settings: FOSC/4,

FOSC/8, FOSC/16

• The PWM Time Base Prescale bits

(PTCKPS<1:0>) are set to any of the following

prescale ratios: FOSC/16, FOSC/64, FOSC/256

2. The dead-time counter is clocked by a pair of

Q clocks when the PWM Time Base Prescale

bits are set to 1:1 (PTCKPS<1:0> = 00, FOSC/4)

and the dead-time counter is clocked by the

FOSC/2 (DTPS<1:0> = 00).

3. The dead-time counter is clocked using every

other Q clock, depending on the two LSbs in the

Duty Cycle registers:

• If the PWM duty cycle match occurs on Q1 or

Q3, then the dead-time counter is clocked

using every Q1 and Q3

• If the PWM duty cycles match occurs on Q2

or Q4, then the dead-time counter is clocked

using every Q2 and Q4

4. When the DTPS<1:0> bits are set to any of the

other dead-time prescaler settings (i.e., FOSC/4,

FOSC/8 or FOSC/16) and the PWM time base pres-

caler is set to 1:1, the dead-time counter is clocked

by the Q clock corresponding to the Q clocks on

which the PWM duty cycle match occurs.

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

DTPS1 DTPS0 DT5 DT4 DT3 DT2 DT1 DT0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-6 DTPS1:DTPS0: Dead-Time Unit A Prescale Select bits

11 = Clock source for dead-time unit is FOSC/16

10 = Clock source for dead-time unit is FOSC/8

01 = Clock source for dead-time unit is FOSC/4

00 = Clock source for dead-time unit is FOSC/2

bit 5-0 DT5:DT0: Unsigned 6-Bit Dead-Time Value for Dead-Time Unit bits

PIC18F1230/1330

The actual dead time is calculated from the DTCON

Dead Time = Dead-Time Value/(FOSC/Prescaler)

Table 13-3 shows example dead-time ranges as a

function of the input clock prescaler selected and the

device operating frequency.

TABLE 13-3: EXAMPLE DEAD-TIME

RANGES

13.7.4 DEAD-TIME DISTORTION

13.8 Independent PWM Output

Independent PWM mode is used for driving the loads

(as shown in Figure 13-19) that drive one winding of a

switched reluctance motor. A particular PWM output

pair is configured in the Independent Output mode

when the corresponding PMODx bit in the PWMCON0

between the PWM I/O pins when the module is operat-

ing in the Independent PWM mode and both I/O pins

are allowed to be active simultaneously. This mode can

also be used to drive stepper motors.

13.8.1 DUTY CYCLE ASSIGNMENT IN THE

INDEPENDENT PWM MODE

In the Independent PWM mode, each duty cycle gener-

ator is connected to both PWM output pins in a given

PWM output pair. The odd and the even PWM output

pins are driven with a single PWM duty cycle generator.

PWM1 and PWM0 are driven by the PWM channel

which uses the PDC0 register to set the duty cycle,

PWM3 and PWM2 with PDC1, and PWM5 and PWM4

with PDC2 (see Figure 13-3 and Register 13-3).

FOSC

(MHz) MIPS Prescaler

Selection

Dead-Time

Min

Dead-Time

Max

40 10 FOSC/2 50 ns 3.2 μs

40 10 FOSC/4 100 ns 6.4 μs

40 10 FOSC/8 200 ns 12.8 μs

40 10 FOSC/16 400 ns 25.6 μs

32 8 FOSC/2 62.5 ns 4 μs

32 8 FOSC/4 125 ns 8 μs

32 8 FOSC/8 250 ns 16 μs

32 8 FOSC/16 500 ns 32 μs

25 6.25 FOSC/2 80 ns 5.12 μs

25 6.25 FOSC/4 160 ns 10.2 μs

25 6.25 FOSC/8 320 ns 20.5 μs

25 6.25 FOSC/16 640 ns 41 μs

20 5 FOSC/2 100 ns 6.4 μs

20 5 FOSC/4 200 ns 12.8 μs

20 5 FOSC/8 400 ns 25.6 μs

20 5 FOSC/16 800 ns 51.2 μs

10 2.5 FOSC/2 200 ns 12.8 μs

10 2.5 FOSC/4 400 ns 25.6 μs

10 2.5 FOSC/8 800 ns 51.2 μs

10 2.5 FOSC/16 1.6 μs 102.4 μs

51.25FOSC/2 400 ns 25.6 μs

51.25FOSC/4 800 ns 51.2 μs

51.25F

OSC/8 1.6 μs 102.4 μs

51.25FOSC/16 3.2 μs 204.8 μs

41F

OSC/2 0.5 μs32 μs

41F

OSC/4 1 μs64 μs

41FOSC/8 2 μs128 μs

41F

OSC/16 4 μs256 μs

Note 1: For small PWM duty cycles, the ratio of

dead time to the active PWM time may

become large. In this case, the inserted

dead time will introduce distortion into

waveforms produced by the PWM mod-

ule. The user can ensure that dead-time

distortion is minimized by keeping the

PWM duty cycle at least three times

larger than the dead time. A similar effect

occurs for duty cycles at or near 100%.

The maximum duty cycle used in the

application should be chosen such that

the minimum inactive time of the signal is

at least three times larger than the dead

time. If the dead time is greater or equal

to the duty cycle of one of the PWM

output pairs, then that PWM pair will be

inactive for the whole period.

2: Changing the dead-time values in

DTCON when the PWM is enabled may

result in an undesirable situation. Disable

the PWM (PTEN = 0) before changing the

dead-time value.

PIC18F1230/1330

13.8.2 PWM CHANNEL OVERRIDE

PWM output may be manually overridden for each

PWM channel by using the appropriate bits in the

OVDCOND and OVDCONS registers. The user may

select the following signal output options for each PWM

output pin operating in the Independent PWM mode:

• I/O pin outputs PWM signal

• I/O pin inactive

• I/O pin active

Refer to Section 13.10 “PWM Output Override” for

details for all the override functions.

FIGURE 13-19: CENTER CONNECTED

LOAD

13.9 Single-Pulse PWM Operation

The single-pulse PWM operation is available only in

Edge-Aligned mode. In this mode, the PWM module

will produce single-pulse output. Single-pulse

operation is configured when the PTMOD1:PTMOD0

bits are set to ‘01’ in the PTCON0 register. This mode

of operation is useful for driving certain types of ECMs.

In Single-Pulse mode, the PWM I/O pin(s) are driven to

the active state when the PTEN bit is set. When the

PWM timer match with Duty Cycle register occurs, the

PWM I/O pin is driven to the inactive state. When the

PWM timer match with the PTPER register occurs, the

PTMR register is cleared, all active PWM I/O pins are

driven to the inactive state, the PTEN bit is cleared and

an interrupt is generated if the corresponding interrupt

bit is set.

13.10 PWM Output Override

The PWM output override bits allow the user to

manually drive the PWM I/O pins to specified logic

states, independent of the duty cycle comparison units.

The PWM override bits are useful when controlling

various types of ECMs, like a BLDC motor.

OVDCOND and OVDCONS registers are used to

define the PWM override options. The OVDCOND

determine which PWM I/O pins will be overridden. The

OVDCONS register contains six bits, POUT5:POUT0,

that determine the state of the PWM I/O pins when a

particular output is overridden via the POVD bits.

The POVD bits are active-low control bits. When the

POVD bits are set, the corresponding POUT bit will

have no effect on the PWM output. In other words, the

pins corresponding to POVD bits that are set will have

the duty PWM cycle set by the PDCx registers. When

one of the POVD bits is cleared, the output on the

corresponding PWM I/O pin will be determined by the

state of the POUT bit. When a POUT bit is set, the

PWM pin will be driven to its active state. When the

POUT bit is cleared, the PWM pin will be driven to its

inactive state.

13.10.1 COMPLEMENTARY OUTPUT MODE

The even numbered PWM I/O pins have override

restrictions when a pair of PWM I/O pins are operating

in the Complementary mode (PMODx = 0). In

Complementary mode, if the even numbered pin is

driven active by clearing the corresponding POVD bit

and by setting the POUT bits in the OVDCOND and

OVDCONS registers, the output signal is forced to be

the complement of the odd numbered I/O pin in the pair

(see Figure 13-2 for details).

13.10.2 OVERRIDE SYNCHRONIZATION

If the OSYNC bit in the PWMCON1 register is set, all

output overrides performed via the OVDCOND and

OVDCONS registers will be synchronized to the PWM

time base. Synchronous output overrides will occur on

the following conditions:

• When the PWM is in Edge-Aligned mode,

synchronization occurs when PTMR is zero.

• When the PWM is in Center-Aligned mode,

synchronization occurs when PTMR is zero and

when the value of PTMR matches PTPER.

Note: PTPER and PDCx values are held as they

are after the single-pulse output. To have

another cycle of single pulse, only PTEN

has to be enabled.

PWM1

PWM0

Load

Note 1: In the Complementary mode, the even

channel cannot be forced active by a

Fault or override event when the odd

channel is active. The even channel is

always the complement of the odd

channel, with dead-time inserted, before

the odd channel can be driven to its active

state as shown in Figure 13-20.

2: Dead time inserted in the PWM channels

even when they are in Override mode.

PIC18F1230/1330

FIGURE 13-20: OVERRIDE BITS IN COMPLEMENTARY MODE

1. Even override bits have no effect in Complementary mode.

2. Odd override bit is activated which causes the even PWM to deactivate.

3. Dead-time insertion.

4. Odd PWM activated after the dead time.

5. Odd override bit is deactivated which causes the odd PWM to deactivate.

6. Dead-time insertion.

7. Even PWM is activated after the dead time.

POUT0

POUT1

PWM1

PWM0

Assume: POVD0 = 0; POVD1 = 0; PMOD0 = 0

PIC18F1230/1330

13.10.3 OUTPUT OVERRIDE EXAMPLES

Figure 13-21 shows an example of a waveform that

might be generated using the PWM output override

feature. The figure shows a six-step commutation

sequence for a BLDC motor. The motor is driven

through a 3-phase inverter as shown in Figure 13-16.

When the appropriate rotor position is detected, the

PWM outputs are switched to the next commutation

state in the sequence. In this example, the PWM

outputs are driven to specific logic states. The

OVDCOND and OVDCONS register values used to

generate the signals in Figure 13-21 are given in

Table 13-4.

The PWM Duty Cycle registers may be used in

conjunction with the OVDCOND and OVDCONS

registers. The Duty Cycle registers control the average

voltage across the load and the OVDCOND and

OVDCONS registers control the commutation

sequence. Figure 13-22 shows the waveforms, while

Table 13-4 and Table 13-5 show the OVDCOND and

OVDCONS register values used to generate the

signals.

U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1

—— POVD5 POVD4 POVD3 POVD2 POVD1 POVD0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-6 Unimplemented: Read as ‘0’

bit 5-0 POVD5:POVD0: PWM Output Override bits

1 = Output on PWM I/O pin is controlled by the value in the Duty Cycle register and the PWM time base

0 = Output on PWM I/O pin is controlled by the value in the corresponding POUTx bit

U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

—— POUT5 POUT4 POUT3 POUT2 POUT1 POUT0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-6 Unimplemented: Read as ‘0’

bit 5-0 POUT5:POUT0: PWM Manual Output bits

1 = Output on PWM I/O pin is active when the corresponding PWM output override bit is cleared

0 = Output on PWM I/O pin is inactive when the corresponding PWM output override bit is cleared

PIC18F1230/1330

FIGURE 13-21: PWM OUTPUT OVERRIDE

EXAMPLE #1

TABLE 13-4: PWM OUTPUT OVERRIDE

EXAMPLE #1

TABLE 13-5: PWM OUTPUT OVERRIDE

EXAMPLE #2

FIGURE 13-22: PWM OUTPUT OVERRIDE

EXAMPLE #2

13.11 PWM Output and Polarity Control

There are three device Configuration bits associated

with the PWM module that provide PWM output pin

control defined in the CONFIG3L register. They are:

•HPOL

•LPOL

•PWMPIN

These three Configuration bits work in conjunction with

the three PWM Enable bits (PWMEN2:PWMEN0) in

the PWMCON0 register. The Configuration bits and

PWM enable bits ensure that the PWM pins are in the

correct states after a device Reset occurs.

13.11.1 OUTPUT PIN CONTROL

The PWMEN2:PWMEN0 control bits enable each

PWM output pin as required in the application.

All PWM I/O pins are general purpose I/O. When a pair

of pins is enabled for PWM output, the PORT and TRIS

registers controlling the pins are disabled. Refer to

Figure 13-23 for details.

13.11.2 OUTPUT POLARITY CONTROL

The polarity of the PWM I/O pins is set during device

programming via the HPOL and LPOL Configuration

bits in the CONFIG3L register. The HPOL Configura-

tion bit sets the output polarity for the high side PWM

outputs: PWM1, PWM3 and PWM5. The polarity is

active-high when HPOL is cleared (= 0) and active-low

when it is set (= 1).

The LPOL Configuration bit sets the output polarity for

the low side PWM outputs: PWM0, PWM2 and PWM4.

As with HPOL, they are active-high when LPOL is

cleared and active-low when set.

All output signals generated by the PWM module are

referenced to the polarity control bits, including those

generated by Fault inputs or manual override (see

Section 13.10 “PWM Output Override”).

The default polarity Configuration bits have the PWM

I/O pins in active-high output polarity.

State OVDCOND (POVD) OVDCONS (POUT)

100000000b 00100100b

200000000b 00100001b

300000000b 00001001b

400000000b 00011000b

500000000b 00010010b

600000000b 00000110b

State OVDCOND (POVD) OVDCONS (POUT)

100000011b 00000000b

200110000b 00000000b

300111100b 00000000b

400001111b 00000000b

PWM5

PWM4

PWM3

PWM2

PWM1

PWM0

123456

PWM5

PWM4

PWM3

PWM2

PWM1

PWM0

1234

PIC18F1230/1330

FIGURE 13-23: PWM I/O PIN BLOCK DIAGRAM

13.11.3 PWM OUTPUT PIN RESET STATES

The PWMPIN Configuration bit determines the PWM

output pins to be PWM output pins, or digital I/O pins,

after the device comes out of Reset. If the PWMPIN

Configuration bit is unprogrammed (default), the

PWMEN2:PWMEN0 control bits will be cleared on a

device Reset. Consequently, all PWM outputs will be

tri-stated and controlled by the corresponding PORT

and TRIS registers. If the PWMPIN Configuration bit is

programmed low, the PWMEN2:PWMEN0 control bits

will be set to ‘100’ on a device Reset:

All PWM pins will be enabled for PWM output and will

have the output polarity defined by the HPOL and

LPOL Configuration bits.

13.12 PWM Fault Input

There is one Fault input associated with the PWM

module. The main purpose of the input Fault pin is to

disable the PWM output signals and drive them into an

inactive state. The action of the Fault input is performed

directly in hardware so that when a Fault occurs, it can

be managed quickly and the PWMs outputs are put into

an inactive state to save the power devices connected

to the PWMs.

The PWM Fault input is FLTA, which can come from

I/O pins, the CPU or another module. The FLTA pin is

an active-low input so it is easy to “OR” many sources

to the same input.

The FLTCONFIG register (Register 13-8) defines the

settings of the FLTA input.

13.12.1 FAULT PIN ENABLE BIT

By setting the bit FLTAEN in the FLTCONFIG register,

the corresponding Fault input is enabled. If FLTAEN bit

is cleared, then the Fault input has no effect on the

PWM module.

Data Bus

WR PORT

WR TRIS

RD PORT

Data Latch

TRIS Latch

VSS

I/O pin

VDD

RD TRIS Schmitt

Trigger

TTL or

PWM Pin Enable

PWM Signal from Module

Note: I/O pin has protection diodes to VDD and VSS. PWM polarity selection logic not shown for clarity.

Note: The inactive state of the PWM pins is

dependent on the HPOL and LPOL Con-

figuration bit settings, which define the

active and inactive state for PWM outputs.

PIC18F1230/1330

13.12.2 FAULT INPUT MODE

The FLTAMOD bit in the FLTCONFIG register

determines whether the PWM I/O pins are deactivated

when they are overridden by a Fault input.

FLTAS bit in the FLTCONFIG register gives the status

of the Fault A input.

The Fault input has two modes of operation:

• Inactive Mode (FLTAMOD = 0)

This is a catastrophic Fault Management mode.

When the Fault occurs in this mode, the PWM

outputs are deactivated. The PWM pins will remain in

Inactivated mode until the Fault is cleared (Fault

input is driven high) and the corresponding Fault

status bit has been cleared in software. The PWM

outputs are enabled immediately at the beginning of

the following PWM period, after Fault status bit

(FLTAS) is cleared.

• Cycle-by-Cycle Mode (FLTAMOD = 1)

When the Fault occurs in this mode, the PWM

outputs are deactivated. The PWM outputs will

remain in the defined Fault states (all PWM outputs

inactive) for as long as the Fault pin is held low. After

the Fault pin is driven high, the PWM outputs will

return to normal operation at the beginning of the

following PWM period and the FLTAS bit is

automatically cleared.

13.12.3 PWM OUTPUTS WHILE IN FAULT

CONDITION

While in the Fault state (i.e., FLTA input is active), the

PWM output signals are driven into their inactive

states.

13.12.4 PWM OUTPUTS IN DEBUG MODE

The BRFEN bit in the FLTCONFIG register controls the

simulation of Fault condition when a breakpoint is hit,

while debugging the application using an In-Circuit

Debugger (ICD). Setting the BRFEN bit to high enables

the Fault condition on breakpoint, thus driving the PWM

outputs to inactive state. This is done to avoid any

continuous keeping of status on the PWM pin, which

may result in damage of the power devices connected

to the PWM outputs.

If BRFEN = 0, the Fault condition on breakpoint is

disabled.

Note: It is highly recommended to enable the

Fault condition on breakpoint if a

debugging tool is used while developing

the firmware and the high-power circuitry

is used. When the device is ready to

program after debugging the firmware, the

BRFEN bit can be disabled.

R/W-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0 R/W-0

BRFEN — — — — FLTAS FLTAMOD FLTAEN

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 BRFEN: Breakpoint Fault Enable bit

1 = Enable Fault condition on a breakpoint

0 = Disable Fault condition

bit 6-3 Unimplemented: Read as ‘0’

bit 2 FLTAS: Fault A Status bit

1 =FLTA is asserted:

if FLTAMOD = 0, cleared by the user;

if FLTAMOD = 1, cleared automatically at beginning of the new period when FLTA is deasserted

0 =No Fault

bit 1 FLTAMOD: Fault A Mode bit

1 = Cycle-by-Cycle mode: Pins are inactive for the remainder of the current PWM period or until FLTA

is deasserted; FLTAS is cleared automatically

0 = Inactive mode: Pins are deactivated (catastrophic failure) until FLTA is deasserted and FLTAS is

cleared by the user only

bit 0 FLTAEN: Fault A Enable bit

1 = Enable Fault A

0 = Disable Fault A

PIC18F1230/1330

13.13 PWM Update Lockout

For a complex PWM application, the user may need to

write up to four Duty Cycle registers and the PWM Time

Base Period Register, PTPER, at a given time. In some

applications, it is important that all buffer registers be

written before the new duty cycle and period values are

loaded for use by the module.

A PWM update lockout feature may optionally be

enabled so the user may specify when new duty cycle

buffer values are valid. The PWM update lockout

feature is enabled by setting the control bit, UDIS, in

the PWMCON1 register. This bit affects all Duty Cycle

Buffer registers and the PWM Time Base Period

To perform a PWM update lockout:

1. Set the UDIS bit.

2. Write all Duty Cycle registers and PTPER, if

applicable.

3. Clear the UDIS bit to re-enable updates.

4. With this, when UDIS bit is cleared, the buffer

values will be loaded to the actual registers. This

makes a synchronous loading of the registers.

13.14 PWM Special Event Trigger

The PWM module has a Special Event Trigger

capability that allows A/D conversions to be

synchronized to the PWM time base. The A/D sampling

and conversion time may be programmed to occur at

any point within the PWM period. The Special Event

Trigger allows the user to minimize the delay between

the time when A/D conversion results are acquired and

the time when the duty cycle value is updated.

The PWM 16-bit Special Event Trigger register,

SEVTCMP (high and low), and five control bits in the

PWMCON1 register are used to control its operation.

The PTMR value for which a Special Event Trigger

should occur is loaded into the SEVTCMP register pair.

SEVTDIR bit in PWMCON1 register specifies the

counting phase when the PWM time base is in a

Continuous Up/Down Count mode.

If the SEVTDIR bit is cleared, the Special Event Trigger

will occur on the upward counting cycle of the PWM

time base. If SEVTDIR is set, the Special Event Trigger

will occur on the downward count cycle of the PWM

time base. The SEVTDIR bit only effects this operation

when the PWM timer is in the Continuous Up/Down

Count mode.

13.14.1 SPECIAL EVENT TRIGGER ENABLE

The PWM module will always produce Special Event

Trigger pulses. This signal may optionally be used by

the A/D module. Refer to Chapter 15.0 "10-Bit

Analog-to-Digital Converter (A/D) Module" for

details.

13.14.2 SPECIAL EVENT TRIGGER

POSTSCALER

The PWM Special Event Trigger has a postscaler that

allows a 1:1 to 1:16 postscale ratio. The postscaler is

configured by writing the SEVOPS3:SEVOPS0 control

bits in the PWMCON1 register.

The Special Event Trigger output postscaler is cleared

on any write to the SEVTCMP register pair, or on any

device Reset.

Note: The Special Event Trigger will take place

only for non-zero values in the SEVTCMP

registers.

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 139
TABLE 13-6: REGISTERS ASSOCIATED WITH THE POWER CONTROL PWM MODULE
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values 
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
IPR3 — — —PTIP— — — —43
PIE3 — — —PTIE— — — —43
PIR3 — — —PTIF— — — —43
PTCON0 PTOPS3 PTOPS2 PTOPS1 PTOPS0 PTCKPS1 PTCKPS
0
PTMOD1 PTMOD0 43
PTCON1 PTEN PTDIR — — — — — —43
PTMRL(1) PWM Time Base Register (lower 8 bits) 43
PTMRH(1) — — — — PWM Time Base Register (upper 4 bits) 43
PTPERL(1) PWM Time Base Period Register (lower 8 bits) 43
PTPERH(1) — — — — PWM Time Base Period Register 
(upper 4 bits)
43
SEVTCMPL(1) PWM Special Event Compare Register (lower 8 bits) 43
SEVTCMPH(1) — — — — PWM Special Event Compare Register 
(upper 4 bits)
44
PWMCON0 —PWMEN2(2) PWMEN1(2) PWMEN0(2) —PMOD2 PMOD1 PMOD0 44
PWMCON1 SEVOPS3 SEVOPS2 SEVOPS1 SEVOPS0 SEVTDIR — UDIS OSYNC 44
DTCON DTPS1 DTPS0 DT5 DT4 DT3 DT2 DT1 DT0 44
FLTCONFIG BRFEN — — — — FLTAS FLTAMOD FLTAEN 43
OVDCOND —— POVD5 POVD4 POVD3 POVD2 POVD1 POVD0 44
OVDCONS —— POUT5 POUT4 POUT3 POUT2 POUT1 POUT0 44
PDC0L(1) PWM Duty Cycle #0L Register (lower 8 bits) 43
PDC0H(1) —— PWM Duty Cycle #0H Register (upper 6 bits) 43
PDC1L(1) PWM Duty Cycle #1L Register (lower 8 bits) 43
PDC1H(1) —— PWM Duty Cycle #1H Register (upper 6 bits) 43
PDC2L(1) PWM Duty Cycle #2L Register (lower 8 bits) 43
PDC2H(1) —— PWM Duty Cycle #2H Register (upper 6 bits) 43
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used with the Power Control PWM.
Note 1: Double-buffered register pairs. Refer to text for explanation of how these registers are read and written to.
2: Reset condition of PWMEN bits depends on the PWMPIN Configuration bit.

PIC18F1230/1330

NOTES:

PIC18F1230/1330

14.0 ENHANCED UNIVERSAL

SYNCHRONOUS

ASYNCHRONOUS RECEIVER

TRANSMITTER (EUSART)

The Enhanced Universal Synchronous Asynchronous

Receiver Transmitter (EUSART) module is one of the

two serial I/O modules. (Generically, the USART is also

known as a Serial Communications Interface or SCI.)

The EUSART can be configured as a full-duplex

asynchronous system that can communicate with

peripheral devices, such as CRT terminals and

personal computers. It can also be configured as a half-

duplex synchronous system that can communicate

with peripheral devices, such as A/D or D/A integrated

circuits, serial EEPROMs, etc.

The Enhanced USART module implements additional

features, including automatic baud rate detection and

calibration, automatic wake-up on Sync Break reception

and 12-bit Break character transmit. These features

make it ideally suited for use in Local Interconnect

Network bus (LIN bus) systems.

The EUSART can be configured in the following

modes:

• Asynchronous (full-duplex) with:

- Auto-Wake-up on Character Reception

- Auto-Baud Calibration

- 12-Bit Break Character Transmission

• Synchronous – Master (half-duplex) with

Selectable Clock Polarity

• Synchronous – Slave (half-duplex) with

Selectable Clock Polarity

The pins of the Enhanced USART are multiplexed

with PORTA. In order to configure RA2/TX/CK and

RA3/RX/DT as an EUSART:

• bit SPEN (RCSTA<7>) must be set (= 1)

• bit TRISA<3> must be set (= 1)

• bit TRISA<2> must be set (= 1)

The operation of the Enhanced USART module is

controlled through three registers:

• Transmit Status and Control (TXSTA)

• Receive Status and Control (RCSTA)

• Baud Rate Control (BAUDCON)

These are detailed on the following pages in

respectively.

Note: The EUSART control will automatically

reconfigure the pin from input to output as

needed.

PIC18F1230/1330

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-1 R/W-0

CSRC TX9 TXEN(1) SYNC SENDB BRGH TRMT TX9D

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 CSRC: Clock Source Select bit

Asynchronous mode:

Don’t care.

Synchronous mode:

1 = Master mode (clock generated internally from BRG)

0 = Slave mode (clock from external source)

bit 6 TX9: 9-Bit Transmit Enable bit

1 = Selects 9-bit transmission

0 = Selects 8-bit transmission

bit 5 TXEN: Transmit Enable bit(1)

1 = Transmit enabled

0 = Transmit disabled

bit 4 SYNC: EUSART Mode Select bit

1 = Synchronous mode

0 = Asynchronous mode

bit 3 SENDB: Send Break Character bit

Asynchronous mode:

1 = Send Sync Break on next transmission (cleared by hardware upon completion)

0 = Sync Break transmission completed

Synchronous mode:

Don’t care.

bit 2 BRGH: High Baud Rate Select bit

Asynchronous mode:

1 = High speed

0 = Low speed

Synchronous mode:

Unused in this mode.

bit 1 TRMT: Transmit Shift Register Status bit

1 = TSR empty

0 = TSR full

bit 0 TX9D: 9th bit of Transmit Data

Can be address/data bit or a parity bit.

Note 1: SREN/CREN overrides TXEN in Sync mode.

PIC18F1230/1330

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x

SPEN RX9 SREN CREN ADDEN FERR OERR RX9D

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 SPEN: Serial Port Enable bit

1 = Serial port enabled (configures 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, enables interrupt and loads the receive buffer when RSR<8> is set

0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit

Asynchronous mode 9-bit (RX9 = 0):

Don’t care.

bit 2 FERR: Framing Error bit

1 = Framing error (can be updated by reading RCREG register and receiving next valid byte)

0 = No framing error

bit 1 OERR: Overrun Error bit

1 = Overrun error (can be cleared by clearing bit CREN)

0 = No overrun error

bit 0 RX9D: 9th bit of Received Data

This can be address/data bit or a parity bit and must be calculated by user firmware.

PIC18F1230/1330

R/W-0 R-1 U-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0

ABDOVF RCIDL — SCKP BRG16 — WUE ABDEN

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 ABDOVF: Auto-Baud Acquisition Rollover Status bit

1 = A BRG rollover has occurred during Auto-Baud Rate Detect mode (must be cleared in software)

0 = No BRG rollover has occurred

bit 6 RCIDL: Receive Operation Idle Status bit

1 = Receive operation is Idle

0 = Receive operation is active

bit 5 Unimplemented: Read as ‘0’

bit 4 SCKP: Synchronous Clock Polarity Select bit

Asynchronous mode:

Unused in this mode.

Synchronous mode:

1 = Idle state for clock (CK) is a high level

0 = Idle state for clock (CK) is a low level

bit 3 BRG16: 16-Bit Baud Rate Register Enable bit

1 = 16-bit Baud Rate Generator – SPBRGH and SPBRG

0 = 8-bit Baud Rate Generator – SPBRG only (Compatible mode), SPBRGH value ignored

bit 2 Unimplemented: Read as ‘0’

bit 1 WUE: Wake-up Enable bit

Asynchronous mode:

1 = EUSART will continue to sample the RX pin – interrupt generated on falling edge; bit cleared in

hardware on following rising edge

0 = RX pin not monitored or rising edge detected

Synchronous mode:

Unused in this mode.

bit 0 ABDEN: Auto-Baud Detect Enable bit

Asynchronous mode:

1 = Enable baud rate measurement on the next character. Requires reception of a Sync field (55h);

cleared in hardware upon completion

0 = Baud rate measurement disabled or completed

Synchronous mode:

Unused in this mode.

PIC18F1230/1330

14.1 Baud Rate Generator (BRG)

The BRG is a dedicated 8-bit or 16-bit generator that

supports both the Asynchronous and Synchronous

modes of the EUSART. By default, the BRG operates

in 8-bit mode; setting the BRG16 bit (BAUDCON<3>)

selects 16-bit mode.

The SPBRGH:SPBRG register pair controls the period

of a free-running timer. In Asynchronous mode, bits

BRGH (TXSTA<2>) and BRG16 (BAUDCON<3>) also

control the baud rate. In Synchronous mode, BRGH is

ignored. Table 14-1 shows the formula for computation

of the baud rate for different EUSART modes which

only apply in Master mode (internally generated clock).

Given the desired baud rate and FOSC, the nearest

integer value for the SPBRGH:SPBRG registers can be

calculated using the formulas in Table 14-1. From this,

the error in baud rate can be determined. An example

calculation is shown in Example 14-1. Typical baud

rates and error values for the various Asynchronous

modes are shown in Table 14-2. It may be advantageous

to use the high baud rate (BRGH = 1), or the 16-bit BRG

to reduce the baud rate error, or achieve a slow baud

rate for a fast oscillator frequency.

Writing a new value to the SPBRGH:SPBRG registers

causes the BRG timer to be reset (or cleared). This

ensures the BRG does not wait for a timer overflow

before outputting the new baud rate.

14.1.1 OPERATION IN POWER-MANAGED

MODES

The device clock is used to generate the desired baud

rate. When one of the power-managed modes is

entered, the new clock source may be operating at a

different frequency. This may require an adjustment to

the value in the SPBRG register pair.

14.1.2 SAMPLING

The data on the RX pin is sampled three times by a

majority detect circuit to determine if a high or a low

level is present at the RX pin.

TABLE 14-1: BAUD RATE FORMULAS

Configuration Bits BRG/EUSART Mode Baud Rate Formula

SYNC BRG16 BRGH

000 8-bit/Asynchronous FOSC/[64 (n + 1)]

001 8-bit/Asynchronous FOSC/[16 (n + 1)]

010 16-bit/Asynchronous

011 16-bit/Asynchronous

FOSC/[4 (n + 1)]10x 8-bit/Synchronous

11x 16-bit/Synchronous

Legend: x = Don’t care, n = value of SPBRGH:SPBRG register pair

PIC18F1230/1330

EXAMPLE 14-1: CALCULATING BAUD RATE ERROR

TABLE 14-2: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR

For a device wit h F OSC of 16 MHz, desire d baud rat e of 960 0, Asynchronous mode, 8-b it BRG:

Desired B aud Rate = FOSC/(64 ([SPBRGH:SPBRG] + 1))

Solving for SPBRGH:SPBRG:

X=((FOSC/Desi red Baud Rate)/64) – 1

= ((16000000/9600) /64) – 1

= [ 25.042] = 25

Calcu lated Baud Rate = 16000000/(64 (25 + 1))

= 9615

Error = (Calculated Baud Rate – Desired Baud Rate )/D e sired Baud Rate

= (9615 – 9 600)/9600 = 0.16%

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values

on Page:

TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 42

RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 42

BAUDCON ABDOVF RCIDL —SCKP BRG16 —WUE ABDEN 42

SPBRGH EUSART Baud Rate Generator Register High Byte 42

SPBRG EUSART Baud Rate Generator Register Low Byte 42

Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the BRG.

PIC18F1230/1330

TABLE 14-3: BAUD RATES FOR ASYNCHRONOUS MODES

BAUD

RATE

(K)

SYNC = 0, BRGH = 0, BRG16 = 0

FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

0.3————————————

1.2 — — — 1.221 1.73 255 1.202 0.16 129 1.201 -0.16 103

2.4 2.441 1.73 255 2.404 0.16 129 2.404 0.16 64 2.403 -0.16 51

9.6 9.615 0.16 64 9.766 1.73 31 9.766 1.73 15 9.615 -0.16 12

19.2 19.531 1.73 31 19.531 1.73 15 19.531 1.73 7 — — —

57.6 56.818 -1.36 10 62.500 8.51 4 52.083 -9.58 2 — — —

115.2 125.000 8.51 4 104.167 -9.58 2 78.125 -32.18 1 — — —

BAUD

RATE

(K)

SYNC = 0, BRGH = 0, BRG16 = 0

FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

0.3 0.300 0.16 207 0.300 -0.16 103 0.300 -0.16 51

1.2 1.202 0.16 51 1.201 -0.16 25 1.201 -0.16 12

2.4 2.404 0.16 25 2.403 -0.16 12 — — —

9.6 8.929 -6.99 6 — — — — — —

19.2 20.833 8.51 2 — — — — — —

57.6 62.500 8.51 0 — — — — — —

115.2 62.500 -45.75 0 — — — — — —

BAUD

RATE

(K)

SYNC = 0, BRGH = 1, BRG16 = 0

FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

0.3————————————

1.2————————————

2.4 — — — — — — 2.441 1.73 255 2.403 -0.16 207

9.6 9.766 1.73 255 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51

19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25

57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8

115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 — — —

BAUD

RATE

(K)

SYNC = 0, BRGH = 1, BRG16 = 0

FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

0.3 — — — — — — 0.300 -0.16 207

1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51

2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25

9.6 9.615 0.16 25 9.615 -0.16 12 — — —

19.2 19.231 0.16 12 — — — — — —

57.6 62.500 8.51 3 — — — — — —

115.2 125.000 8.51 1 — — — — — —

PIC18F1230/1330

BAUD

RATE

(K)

SYNC = 0, BRGH = 0, BRG16 = 1

FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

0.3 0.300 0.00 8332 0.300 0.02 4165 0.300 0.02 2082 0.300 -0.04 1665

1.2 1.200 0.02 2082 1.200 -0.03 1041 1.200 -0.03 520 1.201 -0.16 415

2.4 2.402 0.06 1040 2.399 -0.03 520 2.404 0.16 259 2.403 -0.16 207

9.6 9.615 0.16 259 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51

19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25

57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8

115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 — — —

BAUD

RATE

(K)

SYNC = 0, BRGH = 0, BRG16 = 1

FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

0.3 0.300 0.04 832 0.300 -0.16 415 0.300 -0.16 207

1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51

2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25

9.6 9.615 0.16 25 9.615 -0.16 12 — — —

19.2 19.231 0.16 12 — — — — — —

57.6 62.500 8.51 3 — — — — — —

115.2 125.000 8.51 1 — — — — — —

BAUD

RATE

(K)

SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1

FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

0.3 0.300 0.00 33332 0.300 0.00 16665 0.300 0.00 8332 0.300 -0.01 6665

1.2 1.200 0.00 8332 1.200 0.02 4165 1.200 0.02 2082 1.200 -0.04 1665

2.4 2.400 0.02 4165 2.400 0.02 2082 2.402 0.06 1040 2.400 -0.04 832

9.6 9.606 0.06 1040 9.596 -0.03 520 9.615 0.16 259 9.615 -0.16 207

19.2 19.193 -0.03 520 19.231 0.16 259 19.231 0.16 129 19.230 -0.16 103

57.6 57.803 0.35 172 57.471 -0.22 86 58.140 0.94 42 57.142 0.79 34

115.2 114.943 -0.22 86 116.279 0.94 42 113.636 -1.36 21 117.647 -2.12 16

BAUD

RATE

(K)

SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1

FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

Actual

Rate

(K)

Error

SPBRG

value

(decimal)

0.3 0.300 0.01 3332 0.300 -0.04 1665 0.300 -0.04 832

1.2 1.200 0.04 832 1.201 -0.16 415 1.201 -0.16 207

2.4 2.404 0.16 415 2.403 -0.16 207 2.403 -0.16 103

9.6 9.615 0.16 103 9.615 -0.16 51 9.615 -0.16 25

19.2 19.231 0.16 51 19.230 -0.16 25 19.230 -0.16 12

57.6 58.824 2.12 16 55.555 3.55 8 — — —

115.2 111 .111 -3.55 8 — — — — — —

TABLE 14-3: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)

PIC18F1230/1330

14.1.3 AUTO-BAUD RATE DETECT

The Enhanced USART module supports the automatic

detection and calibration of baud rate. This feature is

active only in Asynchronous mode and while the WUE

bit is clear.

The automatic baud rate measurement sequence

(Figure 14-1) begins whenever a Start bit is received

and the ABDEN bit is set. The calculation is

self-averaging.

In the Auto-Baud Rate Detect (ABD) mode, the clock to

the BRG is reversed. Rather than the BRG clocking the

incoming RX signal, the RX signal is timing the BRG. In

ABD mode, the internal Baud Rate Generator is used

as a counter to time the bit period of the incoming serial

byte stream.

Once the ABDEN bit is set, the state machine will clear

the BRG and look for a Start bit. The Auto-Baud Rate

Detect must receive a byte with the value 55h (ASCII

“U”, which is also the LIN bus Sync character) in order to

calculate the proper bit rate. The measurement is taken

over both a low and a high bit time in order to minimize

any effects caused by asymmetry of the incoming signal.

After a Start bit, the SPBRG begins counting up, using

the preselected clock source on the first rising edge of

RX. After eight bits on the RX pin or the fifth rising edge,

an accumulated value totalling the proper BRG period is

left in the SPBRGH:SPBRG register pair. Once the 5th

edge is seen (this should correspond to the Stop bit), the

ABDEN bit is automatically cleared.

If a rollover of the BRG occurs (an overflow from FFFFh

to 0000h), the event is trapped by the ABDOVF status

bit (BAUDCON<7>). It is set in hardware by BRG

rollovers and can be set or cleared by the user in

software. ABD mode remains active after rollover

events and the ABDEN bit remains set (Figure 14-2).

While calibrating the baud rate period, the BRG

registers are clocked at 1/8th the preconfigured clock

rate. Note that the BRG clock will be configured by the

BRG16 and BRGH bits. Independent of the BRG16 bit

setting, both the SPBRG and SPBRGH will be used as

a 16-bit counter. This allows the user to verify that no

carry occurred for 8-bit modes by checking for 00h in

the SPBRGH register. Refer to Table 14-4 for counter

clock rates to the BRG.

While the ABD sequence takes place, the EUSART

state machine is held in Idle. The RCIF interrupt is set

once the fifth rising edge on RX is detected. The value

in the RCREG needs to be read to clear the RCIF

interrupt. The contents of RCREG should be discarded.

TABLE 14-4: BRG COUNTER

CLOCK RATES

14.1.3.1 ABD and EUSART Transmission

Since the BRG clock is reversed during ABD

acquisition, the EUSART transmitter cannot be used

during ABD. This means that whenever the ABDEN bit

is set, TXREG cannot be written to. Users should also

ensure that ABDEN does not become set during a

transmit sequence. Failing to do this may result in

unpredictable EUSART operation.

Note 1: If the WUE bit is set with the ABDEN bit,

Auto-Baud Rate Detection will occur on

the byte

following

the Break character.

2: It is up to the user to determine that the

incoming character baud rate is within the

range of the selected BRG clock source.

Some combinations of oscillator frequency

and EUSART baud rates are not possible

due to bit error rates. Overall system

timing and communication baud rates

must be taken into consideration when

using the Auto-Baud Rate Detection

feature.

BRG16 BRGH BRG Counter Clock

00 FOSC/512

01 FOSC/128

10 FOSC/128

11 FOSC/32

Note: During the ABD sequence, SPBRG and

SPBRGH are both used as a 16-bit counter,

independent of the BRG16 setting.

PIC18F1230/1330

FIGURE 14-1: AUTOMATIC BAUD RATE CALCULATION

FIGURE 14-2: BRG OVERFLOW SEQUENCE

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 Edge #5

001Ch

Note: The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0.

SPBRG XXXXh 1Ch

SPBRGH XXXXh 00h

Stop bit

Start bit 0

XXXXh 0000h 0000h

FFFFh

BRG Clock

ABDEN bit

RX pin

ABDOVF bit

BRG Value

PIC18F1230/1330

14.2 EUSART Asynchronous Mode

The Asynchronous mode of operation is selected by

clearing the SYNC bit (TXSTA<4>). In this mode, the

EUSART uses standard Non-Return-to-Zero (NRZ)

format (one Start bit, eight or nine data bits and one

Stop bit). The most common data format is 8 bits. An

on-chip dedicated 8-bit/16-bit Baud Rate Generator

can be used to derive standard baud rate frequencies

from the oscillator.

The EUSART transmits and receives the LSb first. The

EUSART’s transmitter and receiver are functionally

independent but use the same data format and baud

rate. The Baud Rate Generator produces a clock, either

x16 or x64 of the bit shift rate depending on the BRGH

and BRG16 bits (TXSTA<2> and BAUDCON<3>). Par-

ity is not supported by the hardware but can be

implemented in software and stored as the 9th data bit.

When operating in Asynchronous mode, the EUSART

module consists of the following important elements:

• Baud Rate Generator

• Sampling Circuit

• Asynchronous Transmitter

• Asynchronous Receiver

• Auto-Wake-up on Sync Break Character

• 12-Bit Break Character Transmit

• Auto-Baud Rate Detection

14.2.1 EUSART ASYNCHRONOUS

TRANSMITTER

The EUSART transmitter block diagram is shown in

Figure 14-3. The heart of the transmitter is the Transmit

(Serial) Shift Register (TSR). The Shift register obtains

its data from the Read/Write Transmit Buffer register,

TXREG. The TXREG register is loaded with data in

software. The TSR register is not loaded until the Stop

bit has been transmitted from the previous load. As

soon as the Stop bit is transmitted, the TSR is loaded

with new data from the TXREG register (if available).

Once the TXREG register transfers the data to the TSR

CY), the TXREG register is empty

and the TXIF flag bit (PIR1<4>) is set. This interrupt can

be enabled or disabled by setting or clearing the interrupt

enable bit, TXIE (PIE1<4>). TXIF will be set regardless of

the state of TXIE; it cannot be cleared in software. TXIF

is also not cleared immediately upon loading TXREG but

becomes valid in the second instruction cycle following

the load instruction. Polling TXIF immediately following a

load of TXREG will return invalid results.

While TXIF indicates the status of the TXREG register,

another bit, TRMT (TXSTA<1>), shows the status of

the TSR register. TRMT is a read-only bit which is set

when the TSR register is empty. No interrupt logic is

tied to this bit so the user has to poll this bit in order to

determine if the TSR register is empty.

To set up an Asynchronous Transmission:

1. Initialize the SPBRGH:SPBRG registers for the

appropriate baud rate. Set or clear the BRGH

and BRG16 bits, as required, to achieve the

desired baud rate.

2. Enable the asynchronous serial port by clearing

bit SYNC and setting bit SPEN.

3. If interrupts are desired, set enable bit TXIE.

4. If 9-bit transmission is desired, set transmit bit

TX9. Can be used as address/data bit.

5. Enable the transmission by setting bit TXEN

which will also set bit TXIF.

6. If 9-bit transmission is selected, the ninth bit

should be loaded in bit TX9D.

7. Load data to the TXREG register (starts

transmission).

8. If using interrupts, ensure that the GIE and PEIE

bits in the INTCON register (INTCON<7:6>) are

set.

FIGURE 14-3: EUSART TRANSMIT BLOCK DIAGRAM

Note 1: The TSR register is not mapped in data

memory so it is not available to the user.

2: Flag bit TXIF is set when enable bit TXEN

is set.

TXIF

TXIE

Interrupt

TXEN Baud Rate CLK

SPBRG

Baud Rate Generator TX9D

MSb LSb

Data Bus

TXREG Register

TSR Register

(8) 0

TX9

TRMT SPEN

TX pin

Pin Buffer

and Control

• • •

SPBRGH

BRG16

PIC18F1230/1330
DS39758C-page 152 Advance Information © 2007 Microchip Technology Inc.
FIGURE 14-4: ASYNCHRONOUS TRANSMISSION       
FIGURE 14-5: ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)        
TABLE 14-5: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION       
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values 
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
PIR1 —ADIF RCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF 43
PIE1 —ADIE RCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE 43
IPR1 —ADIP RCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP 43
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 42
TXREG EUSART Transmit Register 42
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 42
BAUDCON ABDOVF RCIDL —SCKP BRG16 —WUE ABDEN 42
SPBRGH EUSART Baud Rate Generator Register High Byte 42
SPBRG EUSART Baud Rate Generator Register Low Byte 42
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.
Word 1
Word 1
Transmit Shift Reg
Start bit bit 0 bit 1 bit 7/8
Write to TXREG
BRG Output
(Shift Clock)
TX (pin)
TXIF bit
(Transmit Buffer
Reg. Empty Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
1 TCY
Stop bit
Word 1
Transmit Shift Reg.
Write to TXREG
BRG Output
(Shift Clock)
TX (pin)
TXIF bit
(Interrupt Reg. Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Word 1 Word 2
Word 1 Word 2
Stop bit Start bit
Transmit Shift Reg.
Word 1 Word 2
bit 0 bit 1 bit 7/8 bit 0
Note: This timing diagram shows two consecutive transmissions.
1 TCY
1 TCY
Start bit

PIC18F1230/1330

14.2.2 EUSART ASYNCHRONOUS

RECEIVER

The receiver block diagram is shown in Figure 14-6.

The data is received on the RX pin and drives the data

recovery block. The data recovery block is actually a

high-speed shifter operating at x16 times the baud rate,

whereas the main receive serial shifter operates at the

bit rate or at FOSC. This mode would typically be used

in RS-232 systems.

To set up an Asynchronous Reception:

1. Initialize the SPBRGH:SPBRG registers for the

appropriate baud rate. Set or clear the BRGH

and BRG16 bits, as required, to achieve the

desired baud rate.

2. Enable the asynchronous serial port by clearing

bit SYNC and setting bit SPEN.

3. If interrupts are desired, set enable bit RCIE.

4. If 9-bit reception is desired, set bit RX9.

5. Enable the reception by setting bit CREN.

6. Flag bit, RCIF, will be set when reception is

complete and an interrupt will be generated if

enable bit, RCIE, was set.

7. Read the RCSTA register to get the 9th bit (if

enabled) and determine if any error occurred

during reception.

8. Read the 8-bit received data by reading the

RCREG register.

9. If any error occurred, clear the error by clearing

enable bit CREN.

10. If using interrupts, ensure that the GIE and PEIE

bits in the INTCON register (INTCON<7:6>) are

set.

14.2.3 SETTING UP 9-BIT MODE WITH

ADDRESS DETECT

This mode would typically be used in RS-485 systems.

To set up an Asynchronous Reception with Address

Detect Enable:

1. Initialize the SPBRGH:SPBRG registers for the

appropriate baud rate. Set or clear the BRGH

and BRG16 bits, as required, to achieve the

desired baud rate.

2. Enable the asynchronous serial port by clearing

the SYNC bit and setting the SPEN bit.

3. If interrupts are required, set the RCEN bit and

select the desired priority level with the RCIP bit.

4. Set the RX9 bit to enable 9-bit reception.

5. Set the ADDEN bit to enable address detect.

6. Enable reception by setting the CREN bit.

7. The RCIF bit will be set when reception is

complete. The interrupt will be Acknowledged if

the RCIE and GIE bits are set.

8. Read the RCSTA register to determine if any

error occurred during reception, as well as read

bit 9 of data (if applicable).

9. Read RCREG to determine if the device is being

addressed.

10. If any error occurred, clear the CREN bit.

11. If the device has been addressed, clear the

ADDEN bit to allow all received data into the

receive buffer and interrupt the CPU.

FIGURE 14-6: EUSART RECEIVE BLOCK DIAGRAM

x64 Baud Rate CLK

Baud Rate Generator

Pin Buffer

and Control

SPEN

Data

Recovery

CREN OERR FERR

RSR Register

MSb LSb

RX9D RCREG Register

FIFO

Interrupt RCIF

RCIE

Data Bus

÷ 64

÷ 16

Stop Start(8) 7 1 0

RX9

• • •

SPBRGSPBRGH

BRG16 or

÷ 4

PIC18F1230/1330
DS39758C-page 154 Advance Information © 2007 Microchip Technology Inc.
FIGURE 14-7: ASYNCHRONOUS RECEPTION          
TABLE 14-6: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
14.2.4 AUTO-WAKE-UP ON SYNC 
BREAK CHARACTER
During Sleep mode, all clocks to the EUSART are
suspended. Because of this, the Baud Rate Generator
is inactive and a proper byte reception cannot be
performed. The auto-wake-up feature allows the
controller to wake-up due to activity on the RX/DT line
while the EUSART is operating in Asynchronous mode.
The auto-wake-up feature is enabled by setting the
WUE bit (BAUDCON<1>). Once set, the typical 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.)
Following a wake-up event, the module generates an
RCIF interrupt. The interrupt is generated
synchronously to the Q clocks in normal operating
modes (Figure 14-8) and asynchronously if the device
is in Sleep mode (Figure 14-9). The interrupt condition
is cleared by reading the RCREG register.
The WUE bit is automatically cleared once a low-to-
high transition is observed on the RX line following the
wake-up event. At this point, the EUSART module is in
Idle mode and returns to normal operation. This signals
to the user that the Sync Break event is over.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values 
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
PIR1 — ADIF RCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF 43
PIE1 —ADIE RCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE 43
IPR1 —ADIP RCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP 43
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 42
RCREG EUSART Receive Register 42
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 42
BAUDCON ABDOVF RCIDL —SCKP BRG16 — WUE ABDEN 42
SPBRGH EUSART Baud Rate Generator Register High Byte 42
SPBRG EUSART Baud Rate Generator Register Low Byte 42
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.
Start
bit bit 7/8
bit 1bit 0 bit 7/8 bit 0
Stop
bit
Start
bit
Start
bit
bit 7/8 Stop
bit
RX (pin)
Rcv Buffer Reg
Rcv Shift Reg
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.

PIC18F1230/1330

14.2.4.1 Special Considerations Using

Auto-Wake-up

Since auto-wake-up functions by sensing rising edge

transitions on RX/DT, information with any state

changes before the Stop bit may signal a false End-of-

Character and cause data or framing errors. To work

properly, therefore, the initial characters in the

transmission must be all ‘0’s. This can be 00h (8 bytes)

for standard RS-232 devices or 000h (12 bits) for LIN

bus.

Oscillator start-up time must also be considered,

especially in applications using oscillators with longer

start-up intervals (i.e., XT or HS 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.

14.2.4.2 Special Considerations Using

the WUE Bit

The timing of WUE and RCIF events may cause some

confusion when it comes to determining the validity of

received data. As noted, setting the WUE bit places the

EUSART in an Idle mode. The wake-up event causes a

receive interrupt by setting the RCIF bit. The WUE bit is

cleared after this when a rising edge is seen on RX/DT.

The interrupt condition is then cleared by reading the

RCREG register. Ordinarily, the data in RCREG will be

dummy data and should be discarded.

The fact that the WUE bit has been cleared (or is still

set) and the RCIF flag is set should not be used as an

indicator of the integrity of the data in RCREG. Users

should consider implementing a parallel method in

firmware to verify received data integrity.

To assure that no actual data is lost, check the RCIDL

bit to verify that a receive operation is not in process. If

a receive operation is not occurring, the WUE bit may

then be set just prior to entering the Sleep mode.

FIGURE 14-8: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING NORMAL OPERATION

FIGURE 14-9: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

OSC1

WUE bit(1)

RX/DT Line

RCIF

Note 1: The EUSART remains in Idle while the WUE bit is set.

Bit Set by User

Cleared Due to User Read of RCREG

Auto-Cleared

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

OSC1

WUE bit(2)

RX/DT Line

RCIF

Cleared Due to User Read of RCREG

Sleep Command Executed

Note 1: If the wake-up event requires long oscillator warm-up time, the auto-clear of the WUE bit can occur before the oscillator is ready. This

sequence should not depend on the presence of Q clocks.

2: The EUSART remains in Idle while the WUE bit is set.

Sleep Ends

Note 1

Auto-Cleared

Bit Set by User

PIC18F1230/1330

14.2.5 BREAK CHARACTER SEQUENCE

The EUSART module has the capability of sending the

special Break character sequences that are required by

the LIN bus standard. The Break character transmit

consists of a Start bit, followed by twelve ‘0’ bits and a

Stop bit. The Frame Break character is sent whenever

the SENDB and TXEN bits (TXSTA<3> and

TXSTA<5>) are set while the Transmit Shift register is

loaded with data. Note that 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).

Note that the data value written to the TXREG for the

Break character is ignored. The write simply serves the

purpose of initiating the proper sequence.

The TRMT bit indicates when the transmit operation is

active or Idle, just as it does during normal

transmission. See Figure 14-10 for the timing of the

Break character sequence.

14.2.5.1 Break and Sync Transmit Sequence

The following sequence will send a message frame

header made up of a Break, followed by an Auto-Baud

Sync byte. This sequence is typical of a LIN bus master.

1. Configure the EUSART for the desired mode.

2. Set the TXEN and SENDB bits to set up the

Break character.

3. Load the 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. The Sync character now

transmits in the preconfigured mode.

When the TXREG becomes empty, as indicated by the

TXIF, the next data byte can be written to TXREG.

14.2.6 RECEIVING A BREAK CHARACTER

The Enhanced USART module can receive a Break

character in two ways.

The first method forces configuration of the baud rate

at a frequency of 9/13 the typical speed. This allows for

the Stop bit transition to be at the correct sampling

location (13 bits for Break versus Start bit and 8 data

bits for typical data).

The second method uses the auto-wake-up feature

described in Section 14.2.4 “Auto-wake-up on Sync

Break Character”. 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 Rate Detect

feature. For both methods, the user can set the ABDEN

bit once the TXIF interrupt is observed.

FIGURE 14-10: SEND BREAK CHARACTER SEQUENCE

Write to TXREG

BRG Output

(Shift Clock)

Start bit bit 0 bit 1 bit 11 Stop bit

Break

TXIF bit

(Transmit Buffer

Reg. Empty Flag)

TX (pin)

TRMT bit

(Transmit Shift

Reg. Empty Flag)

SENDB

(Transmit Shift

Reg. Empty Flag)

SENDB Sampled Here Auto-Cleared

Dummy Write

PIC18F1230/1330

14.3 EUSART Synchronous

Master Mode

The Synchronous Master mode is entered by setting

the CSRC bit (TXSTA<7>). In this mode, the data is

transmitted in a half-duplex manner (i.e., transmission

and reception do not occur at the same time). When

transmitting data, the reception is inhibited and vice

versa. Synchronous mode is entered by setting bit

SYNC (TXSTA<4>). In addition, enable bit, SPEN

(RCSTA<7>), is set in order to configure the TX and RX

pins to CK (clock) and DT (data) lines, respectively.

The Master mode indicates that the processor

transmits the master clock on the CK line. Clock

polarity is selected with the SCKP bit (BAUDCON<4>).

Setting SCKP sets the Idle state on CK as high, while

clearing the bit sets the Idle state as low. This option is

provided to support Microwire devices with this module.

14.3.1 EUSART SYNCHRONOUS MASTER

TRANSMISSION

The EUSART transmitter block diagram is shown in

Figure 14-3. The heart of the transmitter is the Transmit

(Serial) Shift Register (TSR). The Shift register obtains

its data from the Read/Write Transmit Buffer register,

TXREG. The TXREG register is loaded with data in

software. The TSR register is not loaded until the last

bit has been transmitted from the previous load. As

soon as the last bit is transmitted, the TSR is loaded

with new data from the TXREG (if available).

Once the TXREG register transfers the data to the TSR

the TXIF flag bit (PIR1<4>) is set. The interrupt can be

enabled or disabled by setting or clearing the interrupt

enable bit, TXIE (PIE1<4>). TXIF is set regardless of

the state of enable bit, TXIE; it cannot be cleared in

software. It will reset only when new data is loaded into

the TXREG register.

While flag bit TXIF indicates the status of the TXREG

status of the TSR register. TRMT is a read-only bit which

is set when the TSR is empty. No interrupt logic is tied to

this bit so the user has to poll this bit in order to

determine if the TSR register is empty. The TSR is not

mapped in data memory so it is not available to the user.

To set up a Synchronous Master Transmission:

1. Initialize the SPBRGH:SPBRG registers for the

appropriate baud rate. Set or clear the BRG16

bit, as required, to achieve the desired baud rate.

2. Enable the synchronous master serial port by

setting bits, SYNC, SPEN and CSRC.

3. If interrupts are desired, set enable bit, TXIE.

4. If 9-bit transmission is desired, set bit, TX9.

5. Enable the transmission by setting bit, TXEN.

6. If 9-bit transmission is selected, the ninth bit

should be loaded in bit, TX9D.

7. Start transmission by loading data to the TXREG

8. If using interrupts, ensure that the GIE and PEIE

bits in the INTCON register (INTCON<7:6>) are

set.

FIGURE 14-11: SYNCHRONOUS TRANSMISSION

bit 0 bit 1 bit 7

Word 1

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 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

bit 2 bit 0 bit 1 bit 7

RA3/RX/DT

RA2/TX/CK pin

Write to

TXREG Reg

TXIF bit

(Interrupt Flag)

TXEN bit

‘1’‘1’

Word 2

TRMT bit

Note: Sync Master mode, SPBRG = 0, continuous transmission of two 8-bit words.

RA2/TX/CK pin

(SCKP =

)

(SCKP =

)

Write Word 2

Write Word 1

PIC18F1230/1330
DS39758C-page 158 Advance Information © 2007 Microchip Technology Inc.
FIGURE 14-12: SYNCHRONOUS TRANSMISSION (THROUGH TXEN)       
TABLE 14-7: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION       
RA3/RX/DT pin
RA2/TX/CK pin
Write to
TXREG reg
TXIF bit
TRMT bit
bit 0 bit 1 bit 2 bit 6 bit 7
TXEN bit
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values 
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
PIR1 —ADIF RCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF 43
PIE1 —ADIE RCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE 43
IPR1 —ADIP RCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP 43
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 42
TXREG EUSART Transmit Register 42
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 42
BAUDCON ABDOVF RCIDL —SCKPBRG16—WUE ABDEN 42
SPBRGH EUSART Baud Rate Generator Register High Byte 42
SPBRG EUSART Baud Rate Generator Register Low Byte 42
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 159
14.3.2 EUSART SYNCHRONOUS 
MASTER RECEPTION
Once Synchronous mode is selected, reception is
enabled by setting either the Single Receive Enable bit,
SREN (RCSTA<5>), or the Continuous Receive
Enable bit, CREN (RCSTA<4>). Data is sampled on the
RX pin on the falling edge of the clock.
If enable bit, SREN, is set, only a single word is
received. If enable bit, CREN, is set, the reception is
continuous until CREN is cleared. If both bits are set,
then CREN takes precedence.
To set up a Synchronous Master Reception:
1. Initialize the SPBRGH:SPBRG registers for the
appropriate baud rate. Set or clear the BRG16
bit, as required, to achieve the desired baud rate.
2. Enable the synchronous master serial port by
setting bits, SYNC, SPEN and CSRC.
3. Ensure bits, CREN and SREN, are clear.
4. If interrupts are desired, set enable bit, RCIE.
5. If 9-bit reception is desired, set bit, RX9.
6. If a single reception is required, set bit, SREN.
For continuous reception, set bit, CREN.
7. Interrupt flag bit, RCIF, will be set when reception
is complete and an interrupt will be generated if
the enable bit, RCIE, was set.
8. Read the RCSTA register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
9. Read the 8-bit received data by reading the
RCREG register.
10. If any error occurred, clear the error by clearing
bit, CREN.
11. If using interrupts, ensure that the GIE and PEIE bits
in the INTCON register (INTCON<7:6>) are set.
FIGURE 14-13: SYNCHRONOUS RECEPTION (MASTER MODE, SREN)       
TABLE 14-8: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION       
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values 
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
PIR1 — ADIF RCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF 43
PIE1 — ADIE RCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE 43
IPR1 — ADIP RCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP 43
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 42
RCREG EUSART Receive Register 42
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 42
BAUDCON ABDOVF RCIDL — SCKP BRG16 —WUE ABDEN 42
SPBRGH EUSART Baud Rate Generator Register High Byte 42
SPBRG EUSART Baud Rate Generator Register Low Byte 42
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.
CREN bit
RA3/RX/DT
RA2/TX/CK pin
Write to
bit SREN
SREN bit
RCIF bit
(Interrupt)
Read
RXREG
Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q2 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
‘
0
’
bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7
‘
0
’
Q1 Q2 Q3 Q4
Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRGH = 0.
RA2/TX/CK pin
pin
(SCKP = 0)
(SCKP = 1)

PIC18F1230/1330
DS39758C-page 160 Advance Information © 2007 Microchip Technology Inc.
14.4 EUSART Synchronous 
Slave Mode
Synchronous Slave mode is entered by clearing bit,
CSRC (TXSTA<7>). This mode differs from the
Synchronous Master mode in that the shift clock is
supplied externally at the CK pin (instead of being
supplied internally in Master mode). This allows the
device to transfer or receive data while in any low-power
mode. 
14.4.1 EUSART SYNCHRONOUS 
SLAVE TRANSMISSION
The operation of the Synchronous Master and Slave
modes are identical, 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:
a) The first word will immediately transfer to the
TSR register and transmit. 
b) The second word will remain in the TXREG
register. 
c) Flag bit, TXIF, will not be set. 
d) When the first word has been shifted out of TSR,
the TXREG register will transfer the second
word to the TSR and flag bit, TXIF, will now be
set. 
e) If enable bit, TXIE, is set, the interrupt will wake
the chip from Sleep. If the global interrupt is
enabled, the program will branch to the interrupt
vector.
To set up a Synchronous Slave Transmission:
1. Enable the synchronous slave serial port by
setting bits, SYNC and SPEN, and clearing bit,
CSRC.
2. Clear bits, CREN and SREN.
3. If interrupts are desired, set enable bit, TXIE.
4. If 9-bit transmission is desired, set bit, TX9.
5. Enable the transmission by setting enable bit,
TXEN.
6. If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
7. Start transmission by loading data to the TXREG
register.
8. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
TABLE 14-9: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION       
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values 
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
PIR1 —ADIF RCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF 43
PIE1 —ADIE RCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE 43
IPR1 —ADIP RCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP 43
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 42
TXREG EUSART Transmit Register 42
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 42
BAUDCON ABDOVF RCIDL — SCKP BRG16 —WUE ABDEN 42
SPBRGH EUSART Baud Rate Generator Register High Byte 42
SPBRG EUSART Baud Rate Generator Register Low Byte 42
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission.

PIC18F1230/1330
© 2007 Microchip Technology Inc. Advance Information DS39758C-page 161
14.4.2 EUSART SYNCHRONOUS SLAVE 
RECEPTION
The operation of the Synchronous Master and Slave
modes is identical, except in the case of Sleep, or any
Idle mode and bit SREN, which is a “don’t care” in
Slave mode.
If receive is enabled by setting the CREN bit prior to
entering Sleep or any Idle mode, then a word may be
received while in this low-power mode. Once the word
is received, the RSR register will transfer the data to the
RCREG register; if the RCIE enable bit is set, the
interrupt generated will wake the chip from the low-
power mode. If the global interrupt is enabled, the
program will branch to the interrupt vector.
To set up a Synchronous Slave Reception:
1. Enable the synchronous master serial port by
setting bits, SYNC and SPEN, and clearing bit,
CSRC.
2. If interrupts are desired, set enable bit, RCIE.
3. If 9-bit reception is desired, set bit, RX9.
4. To enable reception, set enable bit, CREN.
5. Flag bit, RCIF, will be set when reception is
complete. An interrupt will be generated if
enable bit, RCIE, was set.
6. Read the RCSTA register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
7. Read the 8-bit received data by reading the
RCREG register.
8. If any error occurred, clear the error by clearing
bit, CREN.
9. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
TABLE 14-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION      
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values 
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
PIR1 —ADIF RCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF 43
PIE1 —ADIE RCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE 43
IPR1 —ADIP RCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP 43
RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 42
RCREG EUSART Receive Register 42
TXSTA CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 42
BAUDCON ABDOVF RCIDL —SCKPBRG16—WUE ABDEN 42
SPBRGH EUSART Baud Rate Generator Register High Byte 42
SPBRG EUSART Baud Rate Generator Register Low Byte 42
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.

PIC18F1230/1330

NOTES:

PIC18F1230/1330

15.0 10-BIT ANALOG-TO-DIGITAL

CONVERTER (A/D) MODULE

The Analog-to-Digital (A/D) Converter module has

4 inputs for the 18/20/28-pin devices. This module

allows conversion of an analog input signal to a

corresponding 10-bit digital number in PIC18F1230/

1330 devices.

The module has five registers:

• A/D Result Register High Byte (ADRESH)

• A/D Result Register Low Byte (ADRESL)

• A/D Control Register 0 (ADCON0)

• A/D Control Register 1 (ADCON1)

• A/D Control Register 2 (ADCON2)

The ADCON0 register, shown in Register 15-1,

controls the operation of the A/D module. The

ADCON1 register, shown in Register 15-2, configures

the functions of the port pins. The ADCON2 register,

shown in Register 15-3, configures the A/D clock

source, programmed acquisition time and justification.

R/W-0 U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0

SEVTEN — — — CHS1 CHS0 GO/DONE ADON

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 SEVTEN: Special Event Trigger Enable bit

1 = Special Event Trigger from Power Control PWM module is enabled

0 = Special Event Trigger from Power Control PWM module is disabled (default)

bit 6-4 Unimplemented: Read as ‘0’

bit 3-2 CHS1:CHS0: Analog Channel Select bits

00 = Channel 0 (AN0)

01 = Channel 1 (AN1)

10 = Channel 2 (AN2)

11 = Channel 3 (AN3)

bit 1 GO/DONE: A/D Conversion Status bit

When ADON = 1:

1 = A/D conversion in progress

0 = A/D Idle

bit 0 ADON: A/D On bit

1 = A/D Converter module is enabled

0 = A/D Converter module is disabled

PIC18F1230/1330

U-0 U-0 U-0 R/W-0 R/W-0(1,2) R/W(1) R/W(1) R/W(1)

— — — VCFG0 PCFG3 PCFG2 PCFG1 PCFG0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-5 Unimplemented: Read as ‘0’

bit 4 VCFG0: Voltage Reference Configuration bit (VREF+ source)

1 = Positive reference for the A/D is VREF+

0 = Positive reference for the A/D is AVDD

bit 3 PCFG3: A/D Port Configuration bit for RA6/AN3(1,2)

0 = Port is configured as AN3

1 = Port is configured as RA6

bit 2 PCFG2: A/D Port Configuration bit for RA4/AN2(1)

0 = Port is configured as AN2

1 = Port is configured as RA4

bit 1 PCFG1: A/D Port Configuration bit for RA1/AN1(1)

0 = Port is configured as AN1

1 = Port is configured as RA1

bit 0 PCFG0: A/D Port Configuration bit for RA0/AN0(1)

0 = Port is configured as AN0

1 = Port is configured as RA0

Note 1: These bits reset to ‘0’ to configure the port as an analog input after Reset.

2: This bit is unused and reads as ‘0’ if pin is not configured for use as RA6

PIC18F1230/1330

R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 ADFM: A/D Result Format Select bit

1 = Right justified

0 = Left justified

bit 6 Unimplemented: Read as ‘0’

bit 5-3 ACQT2:ACQT0: A/D Acquisition Time Select bits

111 = 20 T

110 = 16 TAD

101 = 12 TAD

100 = 8 TAD

011 = 6 TAD

010 = 4 TAD

001 = 2 TAD

000 = 0 TAD(1)

bit 2-0 ADCS2:ADCS0: A/D Conversion Clock Select bits

111 = FRC (clock derived from A/D RC oscillator)(1)

110 = FOSC/64

101 = FOSC/16

100 = FOSC/4

011 = FRC (clock derived from A/D RC oscillator)(1)

010 = FOSC/32

001 = FOSC/8

000 = FOSC/2

Note 1: If the A/D FRC clock source is selected, a delay of one TCY (instruction cycle) is added before the A/D

clock starts. This allows the SLEEP instruction to be executed before starting a conversion.

PIC18F1230/1330

The analog reference voltage is software selectable to

the device’s positive supply voltage (VDD), or the

voltage level on the RA4/T0CKI/AN2/VREF+ pin.

The A/D Converter has a unique feature of being able

to operate while the device is in Sleep mode. To

operate in Sleep, the A/D conversion clock must be

derived from the A/D Converter’s internal RC oscillator.

The output of the sample and hold is the input into the

A/D Converter, which generates the result via succes-

sive approximation.

A device Reset forces all registers to their Reset state.

This forces the A/D module to be turned off and any

conversion in progress is aborted.

Each port pin associated with the A/D Converter can be

configured as an analog input or as a digital I/O. The

ADRESH and ADRESL registers contain the result of

the A/D conversion. When the A/D conversion is

complete, the result is loaded into the

ADRESH:ADRESL register pair, the GO/DONE bit

(ADCON0 register) is cleared and A/D Interrupt Flag bit,

ADIF, is set. The block diagram of the A/D module is

shown in Figure 15-1.

FIGURE 15-1: A/D BLOCK DIAGRAM

(Input Voltage)

VAIN

VREF+

Reference

Voltage

AVDD

VCFG0

CHS1:CHS0

AN3

AN2

AN1

AN0

0011

0010

0001

0000

10-Bit

A/D

AVSS

Converter

PIC18F1230/1330

The value in the ADRESH:ADRESL registers is not

modified for a Power-on Reset. The ADRESH:ADRESL

registers will contain unknown data after a Power-on

Reset.

After the A/D module has been configured as desired,

the selected channel must be acquired before the

conversion is started. The analog input channels must

have their corresponding TRIS bits selected as inputs.

To determine acquisition time, see Section 15.2 “A/D

Acquisition Requirements”. After this acquisition

time has elapsed, the A/D conversion can be started.

An acquisition time can be programmed to occur

between setting the GO/DONE bit and the actual start

of the conversion.

The following steps should be followed to perform an A/

D conversion:

1. Configure the A/D module:

• Configure analog pins, voltage reference and

digital I/O (ADCON1)

• Select A/D input channel (ADCON0)

• Select A/D acquisition time (ADCON2)

• Select A/D conversion clock (ADCON2)

• Turn on A/D module (ADCON0)

2. Configure A/D interrupt (if desired):

• Clear ADIF bit

• Set ADIE bit

• Set GIE bit

3. Wait the required acquisition time (if required).

4. Start conversion:

• Set GO/DONE bit (ADCON0 register)

5. Wait for A/D conversion to complete, by either:

• Polling for the GO/DONE bit to be cleared

• Waiting for the A/D interrupt

6. Read A/D Result registers (ADRESH:ADRESL);

clear bit ADIF, if required.

7. For next conversion, go to step 1 or step 2, as

required. The A/D conversion time per bit is

defined as T

AD. A minimum wait of 2 TAD is

required before the next acquisition starts.

FIGURE 15-2: A/D TRANSFER FUNCTION

FIGURE 15-3: ANALOG INPUT MODEL

Digital Code Output

3FEh

003h

002h

001h

000h

0.5 LSB

1 LSB

1.5 LSB

2 LSB

2.5 LSB

1022 LSB

1022.5 LSB

3 LSB

Analog Input Voltage

3FFh

1023 LSB

1023.5 LSB

VAIN CPIN

Rs ANx

5 pF

VT = 0.6V

VT = 0.6V ILEAKAGE

RIC ≤ 1k

Sampling

Switch

SS RSS

CHOLD = 25 pF

VSS

VDD

±100 nA

Legend: CPIN

ILEAKAGE

RIC

CHOLD

= Input Capacitance

= Threshold Voltage

= Leakage Current at the pin due to

= Interconnect Resistance

= Sampling Switch

= Sample/Hold Capacitance (from DAC)

various junctions

= Sampling Switch ResistanceRSS

VDD

Sampling Switch (kΩ)

1234

PIC18F1230/1330

15.1 Triggering A/D Conversions

The A/D conversion can be triggered by setting the GO/

DONE bit. This bit can either be set manually by the

programmer or by setting the SEVTEN bit of ADCON0.

When the SEVTEN bit is set, the Special Event Trigger

from the Power Control PWM module triggers the A/D

conversion. For more information, see Section 13.14

“PWM Special Event Trigger”.

15.2 A/D Acquisition Requirements

For the A/D Converter to meet its specified accuracy,

the charge holding capacitor (CHOLD) must be allowed

to fully charge to the input channel voltage level. The

analog input model is shown in Figure 15-3. The

source impedance (RS) and the internal sampling

switch (RSS) impedance directly affect the time

required to charge the capacitor CHOLD. The sampling

switch (RSS) impedance varies over the device voltage

(VDD). The source impedance affects the offset voltage

at the analog input (due to pin leakage current). The

maximum recommended impedance for analog

sources is 2.5 kΩ. After the analog input channel is

selected (changed), the channel must be sampled for

at least the minimum acquisition time before starting a

conversion.

To calculate the minimum acquisition time,

Equation 15-1 may be used. This equation assumes

that 1/2 LSb error is used (1024 steps for the A/D). The

1/2 LSb error is the maximum error allowed for the A/D

to meet its specified resolution.

Example 15-3 shows the calculation of the minimum

required acquisition time, T

ACQ. This calculation is

based on the following application system

assumptions:

CHOLD =25 pF

Rs = 2.5 kΩ

Conversion Error ≤1/2 LSb

VDD =5V → RSS = 2 kΩ

Temperature = 85°C (system max.)

EQUATION 15-1: ACQUISITION TIME

EQUATION 15-2: A/D MINIMUM CHARGING TIME

EQUATION 15-3: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME

Note: When the conversion is started, the

holding capacitor is disconnected from the

input pin.

TACQ = Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient

AMP + TC + TCOFF

VHOLD = (VREF – (VREF/2048)) • (1 – e(-TC/CHOLD(RIC + RSS + RS)))

TC = -(CHOLD)(RIC + RSS + RS) ln(1/2048)

TACQ =TAMP + TC + TCOFF

TAMP =0.2 μs

TCOFF = (Temp – 25°C)(0.02 μs/°C)

(85°C – 25°C)(0.02 μs/°C)

1.2 μs

Temperature coefficient is only required for temperatures > 25°C. Below 25°C, TCOFF = 0 ms.

TC = -(CHOLD)(RIC + RSS + RS) ln(1/2047)

-(25 pF) (1 kΩ + 2 kΩ + 2.5 kΩ) ln(0.0004883)

1.05 μs

TACQ =0.2 μs + 1 μs + 1.2 μs

2.4 μs

PIC18F1230/1330

15.3 Selecting and Configuring

Acquisition Time

The ADCON2 register allows the user to select an

acquisition time that occurs each time the GO/DONE

bit is set. It also gives users the option to use an

automatically determined acquisition time.

Acquisition time may be set with the ACQT2:ACQT0 bits

(ADCON2<5:3>), which provide a range of 2 to 20 TAD.

When the GO/DONE bit is set, the A/D module

continues to sample the input for the selected acquisition

time, then automatically begins a conversion. Since the

acquisition time is programmed, there may be no need

to wait for an acquisition time between selecting a

channel and setting the GO/DONE bit.

Manual acquisition is selected when

ACQT2:ACQT0 = 000. When the GO/DONE bit is set,

sampling is stopped and a conversion begins. The user

is responsible for ensuring the required acquisition time

has passed between selecting the desired input

channel and setting the GO/DONE bit. This option is

also the default Reset state of the ACQT2:ACQT0 bits

and is compatible with devices that do not offer

programmable acquisition times.

In either case, when the conversion is completed, the

GO/DONE bit is cleared, the ADIF flag is set and the

A/D begins sampling the currently selected channel

again. If an acquisition time is programmed, there is

nothing to indicate if the acquisition time has ended or

if the conversion has begun.

15.4 Selecting the A/D Conversion

Clock

The A/D conversion time per bit is defined as TAD. The

A/D conversion requires 11 T

AD per 10-bit conversion.

The source of the A/D conversion clock is software

selectable. There are seven possible options for TAD:

•2 T

OSC

•4 TOSC

•8 TOSC

•16 TOSC

•32 TOSC

•64 T

OSC

• Internal RC Oscillator

For correct A/D conversions, the A/D conversion clock

(TAD) must be as short as possible, but greater than the

minimum TAD (see parameter 130 for more

information).

Table 15-1 shows the resultant TAD times derived from

the device operating frequencies and the A/D clock

source selected.

TABLE 15-1: TAD vs. DEVICE OPERATING FREQUENCIES

AD Clock Source (TAD) Maximum Device Frequency

Operation ADCS2:ADCS0 PIC18F1230/1330 PIC18LF1230/1330(4)

2 T

OSC 000 2.86 MHz 1.43 kHz

4 T

OSC 100 5.71 MHz 2.86 MHz

8 T

OSC 001 11.43 MHz 5.72 MHz

16 TOSC 101 22.86 MHz 11.43 MHz

32 TOSC 010 40.0 MHz 22.86 MHz

64 TOSC 110 40.0 MHz 22.86 MHz

RC(3) x11 1.00 MHz(1) 1.00 MHz(2)

Note 1: The RC source has a typical TAD time of 1.2 μs.

2: The RC source has a typical TAD time of 2.5 μs.

3: For device frequencies above 1 MHz, the device must be in Sleep for the entire conversion or the A/D

accuracy may be out of specification.

4: Low-power (PIC18LF1230/1330) devices only.

PIC18F1230/1330

15.5 Operation in Power-Managed

Modes

The selection of the automatic acquisition time and A/D

conversion clock is determined in part by the clock

source and frequency while in a power-managed mode.

If the A/D is expected to operate while the device is in

a power-managed mode, the ACQT2:ACQT0 and

ADCS2:ADCS0 bits in ADCON2 should be updated in

accordance with the clock source to be used in that

mode. After entering the mode, an A/D acquisition or

conversion may be started. Once started, the device

should continue to be clocked by the same clock

source until the conversion has been completed.

If desired, the device may be placed into the

corresponding Idle mode during the conversion. If the

device clock frequency is less than 1 MHz, the A/D RC

clock source should be selected.

Operation in Sleep mode requires the A/D FRC clock to

be selected. If bits ACQT2:ACQT0 are set to ‘000’ and

a conversion is started, the conversion will be delayed

one instruction cycle to allow execution of the SLEEP

instruction and entry to Sleep mode. The IDLEN bit

(OSCCON<7>) must have already been cleared prior

to starting the conversion.

15.6 Configuring Analog Port Pins

The ADCON1 and TRISA registers configure the A/D

port pins. The port pins needed as analog inputs must

have their corresponding TRIS bits set (input). If the

TRIS bit is cleared (output), the digital output level (VOH

or VOL) will be converted.

The A/D operation is independent of the state of the

CHS1:CHS0 bits and the TRIS bits.

Note 1: When reading the PORT register, all pins

configured as analog input channels will

read as cleared (a low level). Pins

configured as digital inputs will convert as

analog inputs. Analog levels on a digitally

configured input will be accurately

converted.

2: Analog levels on any pin defined as a

digital input may cause the digital input

buffer to consume current out of the

device’s specification limits.

PIC18F1230/1330

15.7 A/D Conversions

Figure 15-4 shows the operation of the A/D Converter

after the GO/DONE bit has been set and the

ACQT2:ACQT0 bits are cleared. A conversion is

started after the following instruction to allow entry into

Sleep mode before the conversion begins.

Figure 15-5 shows the operation of the A/D Converter

after the GO/DONE bit has been set, the ACQT2:ACQT0

bits are set to ‘010’ and a 4 TAD acquisition time is

selected before the conversion starts.

Clearing the GO/DONE bit during a conversion will abort

the current conversion. The A/D Result register pair will

NOT be updated with the partially completed A/D

conversion sample. This means that the

ADRESH:ADRESL registers will continue to contain the

value of the last completed conversion (or the last value

written to the ADRESH:ADRESL registers).

After the A/D conversion is completed or aborted, a

AD wait is required before the next acquisition can

be started. After this wait, acquisition on the selected

channel is automatically started.

15.8 Discharge

The discharge phase is used to initialize the value of

the capacitor array. The array is discharged before

every sample. This feature helps to optimize the unity-

gain amplifier, as the circuit always needs to charge the

capacitor array, rather than charge/discharge based on

previous measure values.

FIGURE 15-4: A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0)

FIGURE 15-5: A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD)

Note: The GO/DONE bit should NOT be set in

the same instruction that turns on the A/D.

TAD1TAD2TAD3 TAD4 TAD5TAD6TAD7TAD8TAD11

Set GO/DONE bit

Holding capacitor is disconnected from analog input (typically 100 ns)

TAD9 TAD10

– T

ADRESH:ADRESL are loaded, GO/DONE bit is cleared,

ADIF bit is set, holding capacitor is connected to analog input.

Conversion starts

b9 b6 b5 b4 b3 b2 b1

b8 b7

On the following cycle:

TAD1

Discharge

1 2 3456 7 811

Set GO/DONE bit

(Holding capacitor is disconnected)

910

Conversion starts

123 4

(Holding capacitor continues

acquiring input)

TACQT Cycles TAD Cycles

Automatic

Acquisition

Time

b0b9 b6 b5 b4 b3 b2 b1

b8 b7

ADRESH:ADRESL are loaded, GO/DONE bit is cleared,

ADIF bit is set, holding capacitor is connected to analog input.

On the following cycle:

TAD1

Discharge

PIC18F1230/1330
DS39758C-page 172 Advance Information © 2007 Microchip Technology Inc.
TABLE 15-2: REGISTERS ASSOCIATED WITH A/D OPERATION     
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values 
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
PIR1 —ADIFRCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF 43
PIE1 —ADIERCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE 43
IPR1 —ADIPRCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP 43
ADRESH  A/D Result Register High Byte 42
ADRESL  A/D Result Register Low Byte 42
ADCON0 SEVTEN — — — CHS1 CHS0 GO/DONE ADON 42
ADCON1 — — — VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 42
ADCON2 ADFM — ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 42
PORTA RA7(1) RA6(1) RA5(2) RA4 RA3 RA2 RA1 RA0 44
TRISA TRISA7(1) TRISA6(1) PORTA Data Direction Control Register 43
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.
Note 1: PORTA<7:6> and their direction bits are individually configured as port pins based on various primary 
oscillator modes. When disabled, these bits read as ‘0’.
2: The RA5 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0); 
otherwise, RA5 reads as ‘0’. This bit is read-only.

PIC18F1230/1330

16.0 COMPARATOR MODULE

The analog comparator module contains three

comparators. The inputs can be selected from the

analog inputs multiplexed with pins RA0, RB2 and

RB3, as well as the on-chip voltage reference (see

Section 17.0 “Comparator Voltage Reference

Module”). The digital outputs are not available at the

pin level and can only be read through the control

the comparator input.

R-0 R-0 R-0 U-0 U-0 R/W-0 R/W-0 R/W-0

C2OUT C1OUT C0OUT —— CMEN2 CMEN1 CMEN0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 C2OUT: Comparator 2 Output bit

1 = C2 VIN+ > C2 VIN- (CVREF)

0 = C2 VIN+ < C2 VIN- (CVREF)

bit 6 C1OUT: Comparator 1 Output bit

1 = C1 VIN+ > C1 VIN- (CVREF)

0 = C1 VIN+ < C1 VIN- (CVREF)-

bit 5 C0OUT: Comparator 0 Output bit

1 = C0 VIN+ > C0 VIN- (CVREF)

0 = C0 VIN+ < C0 VIN- (CVREF)

bit 4-3 Unimplemented: Read as ‘0’

bit 2 CMEN2: Comparator 2 Enable bit

1 = Comparator 2 is enabled

0 = Comparator 2 is disabled

bit 1 CMEN1: Comparator 1 Enable bit

1 = Comparator 1 is enabled

0 = Comparator 1 is disabled

bit 0 CMEN0: Comparator 0 Enable bit

1 = Comparator 0 is enabled

0 = Comparator 0 is disabled

PIC18F1230/1330

16.1 Comparator Configuration

For every analog comparator, there is a control bit

called CMENx in the CMCON register. By setting the

CMENx bit, the corresponding comparator can be

enabled. If the Comparator mode is changed, the

comparator output level may not be valid for the

specified mode change delay shown in Section 22.0

“Electrical Characteristics”.

16.2 Comparator Operation

A single comparator is shown in Figure 16-1, along with

the relationship between the analog input levels and

the digital output. When the analog input at VIN+

(CMPx) is less than the analog input VIN- (CVREF), the

output of the comparator is a digital low level. When the

analog input at VIN+ (CMPx) is greater than the analog

input VIN- (CVREF), the output of the comparator is a

digital high level. The shaded areas of the output of the

comparator in Figure 16-1 represent the uncertainty

due to input offsets and response time.

16.3 Comparator Reference

In this comparator module, an internal voltage

reference is used (see Section 17.0 “Comparator

Voltage Reference Module”).

FIGURE 16-1: SINGLE COMPARATOR

16.4 Comparator Response Time

Response time is the minimum time, after selecting a

new reference voltage or input source, before the

comparator output has a valid level. If the internal

reference is changed, the maximum delay of the

internal voltage reference must be considered when

using the comparator outputs. Otherwise, the

maximum delay of the comparators should be used

(see Section 22.0 “Electrical Characteristics”).

16.5 Comparator Outputs

The comparator outputs are read through the CxOUT

bits of the CMCON register. These bits are read-only.

The uncertainty of each of the comparators is related to

the input offset voltage and the response time given in

the specifications.

16.6 Comparator Interrupts

The comparator interrupt flag is set whenever there is

a change in the output value of the corresponding

comparator. Software will need to maintain information

about the status of the output bits, as read from

CMCON<7:5>, to determine the actual change that

occurred. The CMPxIF bit (PIR1<3:1>) is the

Comparator Interrupt Flag. The CMPxIF bit must be

reset by clearing it. Since it is also possible to write a ‘1’

to this register, a simulated interrupt may be initiated.

Both the CMPxIE bit (PIE1<3:1>) and the PEIE bit

(INTCON<6>) must be set to enable the interrupt for

the corresponding comparator. In addition, the GIE bit

(INTCON<7>) must also be set. If any of these bits are

clear, the interrupt is not enabled, though the CMPxIF

bit will still be set if an interrupt condition occurs.

The user, in the Interrupt Service Routine, can clear the

interrupt in the following manner:

a) Any read or write of CMCON will end the

mismatch condition.

b) Clear flag bit CMPxIF.

A mismatch condition will continue to set flag bit

CMPxIF. Reading CMCON will end the mismatch

condition and allow flag bit CMPxIF to be cleared.

Note: Comparator interrupts should be disabled

during a Comparator mode change;

otherwise, a false interrupt may occur.

VIN+

Output

VIN-

VIN+

VIN-

Note 1: When reading the PORT register, all pins

configured as analog inputs will read as a

‘0’. Pins configured as digital inputs will

convert an analog input according to the

Schmitt Trigger 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.

Note: If a change in the CMCON register

(C2OUT, C1OUT or C0OUT) should occur

when a read operation is being executed

(start of the Q2 cycle), then the CMPxIF

(PIR1 register) interrupt flag may not get

set.

PIC18F1230/1330

16.7 Comparator Operation

During Sleep

When a comparator is active and the device is placed

in Sleep mode, the comparator remains active and the

interrupt is functional if enabled. This interrupt will

wake-up the device from Sleep mode when enabled.

Each operational comparator will consume additional

current, as shown in the comparator specifications. To

minimize power consumption while in Sleep mode, turn

off the comparators (CMEN2:CMEN0 = 000) before

entering Sleep. If the device wakes up from Sleep, the

contents of the CMCON register are not affected.

16.8 Effects of a Reset

A device Reset forces the CMCON register to its Reset

state, causing the comparator modules to be turned off

(CMEN2:CMEN0 = 000).

16.9 Analog Input Connection

Considerations

A simplified circuit for an analog input is shown in

Figure 16-2. Since the analog pins are connected to a

digital output, they have reverse biased diodes to VDD

and VSS. The analog input, therefore, must be between

VSS and VDD. If the input voltage deviates from this

range by more than 0.6V in either direction, one of the

diodes is forward biased and a latch-up condition may

occur. A maximum source impedance of 10 kΩ is

recommended for the analog sources. Any external

component connected to an analog input pin, such as

a capacitor or Zener diode, should have very little

leakage current.

FIGURE 16-2: COMPARATOR ANALOG INPUT MODEL

RS < 10k

AIN

CPIN

5 pF

VDD

VT = 0.6V

RIC

ILEAKAGE

±500 nA

VSS

Legend: CPIN = Input Capacitance

VT= Threshold Voltage

ILEAKAGE = Leakage Current at the pin due to various junctions

RIC = Interconnect Resistance

RS= Source Impedance

VA = Analog Voltage

Comparator

Input

PIC18F1230/1330
DS39758C-page 176 Advance Information © 2007 Microchip Technology Inc.
TABLE 16-1: REGISTERS ASSOCIATED WITH COMPARATOR MODULE  
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset 
Values 
on Page:
CMCON C2OUT C1OUT C0OUT —— CMEN2 CMEN1 CMEN0 42
CVRCON CVREN —CVRRCVRSS CVR3 CVR2 CVR1 CVR0 42
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41
PIR1 —ADIF RCIF TXIF CMP2IF CMP1IF CMP0IF TMR1IF 43
PIE1 —ADIE RCIE TXIE CMP2IE CMP1IE CMP0IE TMR1IE 43
IPR1 —ADIP RCIP TXIP CMP2IP CMP1IP CMP0IP TMR1IP 43
PORTA RA7(1) RA6(1) RA5(2) RA4 RA3 RA2 RA1 RA0 44
LATA LATA7(1) LATA6(1) PORTA Data Latch Register (Read and Write to Data Latch) 43
TRISA TRISA7(1) TRISA6(1) PORTA Data Direction Control Register 43
PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 44
LATB PORTB Data Latch Register (Read and Write to Data Latch) 43
TRISB PORTB Data Direction Control Register 43
Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the comparator module.
Note 1: PORTA<7:6> and their direction and latch bits are individually configured as port pins based on various 
primary oscillator modes. When disabled, these bits read as ‘0’.
2: The RA5 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0); 
otherwise, RA5 reads as ‘0’. This bit is read-only.

PIC18F1230/1330

17.0 COMPARATOR VOLTAGE

REFERENCE MODULE

The comparator voltage reference is a 16-tap resistor

ladder network that provides a selectable reference

voltage. Its purpose is to provide a reference for the

analog comparators.

A block diagram of the module is shown in Figure 17-1.

The resistor ladder is segmented to provide two ranges

of CVREF values and has a power-down function to

conserve power when the reference is not being used.

The module’s supply reference can be provided from

either device VDD/VSS or an external voltage reference.

17.1 Configuring the Comparator

Voltage Reference

The voltage reference module is controlled through the

CVRCON register (Register 17-1). The comparator

voltage reference provides two ranges of output

voltage, each with 16 distinct levels. The range to be

used is selected by the CVRR bit (CVRCON<5>). The

primary difference between the ranges is the size of the

steps selected by the CVREF selection bits

(CVR3:CVR0), with one range offering finer resolution.

The equations used to calculate the output of the

comparator voltage reference are as follows:

If CVRR = 1:

CVREF = ((CVR3:CVR0)/24) x CVRSRC

If CVRR = 0:

CVREF = (CVRSRC x 1/4) + (((CVR3:CVR0)/32) x

CVRSRC)

The comparator reference supply voltage can come

from either AVDD or AVSS, or the external VREF+ that is

multiplexed with RA4 and AVSS. The voltage source is

selected by the CVRSS bit (CVRCON<4>).

The settling time of the comparator voltage reference

must be considered when changing the CVREF

output (see Table 22-3 in Section 22.0 “Electrical

Characteristics”).

R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0

CVREN — CVRR CVRSS CVR3 CVR2 CVR1 CVR0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7 CVREN: Comparator Voltage Reference Enable bit

1 =CV

REF circuit powered on

0 =CV

REF circuit powered down

bit 6 Unimplemented: Read as ‘0’

bit 5 CVRR: Comparator VREF Range Selection bit

1 = 0 to 0.667 CVRSRC, with CVRSRC/24 step size (low range)

0 = 0.25 CVRSRC to 0.75 CVRSRC, with CVRSRC/32 step size (high range)

bit 4 CVRSS: Comparator VREF Source Selection bit

1 = Comparator reference source, CVRSRC = (VREF+) – (AVSS)

0 = Comparator reference source, CVRSRC = AVDD – AVSS

bit 3-0 CVR3:CVR0: Comparator VREF Value Selection bits (0 ≤ (CVR3:CVR0) ≤ 15)

When CVRR = 1:

CVREF = ((CVR3:CVR0)/24) • (CVRSRC)

When CVRR = 0:

CVREF = (CVRSRC/4) + ((CVR3:CVR0)/32) • (CVRSRC)

PIC18F1230/1330

FIGURE 17-1: COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM

17.2 Voltage Reference Accuracy/Error

The full range of voltage reference cannot be realized

due to the construction of the module. The transistors

on the top and bottom of the resistor ladder network

(Figure 17-1) keep CVREF from approaching the

reference source rails. The voltage reference is derived

from the reference source; therefore, the CVREF output

changes with fluctuations in that source. The tested

absolute accuracy of the voltage reference can be

found in Section 22.0 “Electrical Characteristics”.

17.3 Operation During Sleep

When the device wakes up from Sleep through an

interrupt or a Watchdog Timer time-out, the contents of

the CVRCON register are not affected. To minimize

current consumption in Sleep mode, the voltage

reference should be disabled.

17.4 Effects of a Reset

A device Reset disables the voltage reference by clearing

bit, CVREN (CVRCON<7>). This Reset selects the high-

voltage range by clearing bit, CVRR (CVRCON<5>). The

CVR value select bits are also cleared.

TABLE 17-1: REGISTERS ASSOCIATED WITH COMPARATOR VOLTAGE REFERENCE

16-to-1 MUX

CVR3:CVR0

CVREN

CVRSS = 0

AVDD

VREF+CVRSS = 1

CVRSS = x

AVSS

16 Steps

CVRR

CVREF

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Reset

Values

on Page:

CVRCON CVREN — CVRR CVRSS CVR3 CVR2 CVR1 CVR0 42

CMCON C2OUT C1OUT C0OUT —— CMEN2 CMEN1 CMEN0 42

Legend: Shaded cells are not used with the comparator voltage reference.

PIC18F1230/1330

18.0 LOW-VOLTAGE DETECT (LVD)

PIC18F1230/1330 devices have a Low-Voltage

Detect module (LVD). This is a programmable circuit

that allows the user to specify the device voltage trip

point. If the device experiences an excursion past the

trip point, an interrupt flag is set. If the interrupt is

enabled, the program execution will branch to the

interrupt vector address and the software can then

respond to the interrupt.

The Low-Voltage Detect Control register (Register 18-1)

completely controls the operation of the LVD module.

This allows the circuitry to be “turned off” by the user

under software control, which minimizes the current

consumption for the device.

The block diagram for the LVD module is shown in

Figure 18-1.

U-0 U-0 R-0 R/W-0 R/W-0 R/W-1 R/W-0 R/W-1

—— IRVST LVDEN LVDL3(1) LVDL2(1) LVDL1(1) LVDL0(1)

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-6 Unimplemented: Read as ‘0’

bit 5 IRVST: Internal Reference Voltage Stable Flag bit

1 = Indicates that the voltage detect logic will generate the interrupt flag at the specified voltage

trip point

0 = Indicates that the voltage detect logic will not generate the interrupt flag at the specified voltage

trip point and the LVD interrupt should not be enabled

bit 4 LVDEN: Low-Voltage Detect Power Enable bit

1 = LVD enabled

0 = LVD disabled

bit 3-0 LVDL3:LVDL0: Voltage Detection Limit bits(1)

1111 = Reserved

1110 = Maximum setting

0000 = Minimum setting

Note 1: See Table 22-4 in Section 22.0 “Electrical Characteristics” for the specifications.

PIC18F1230/1330

The module is enabled by setting the LVDEN bit. Each

time that the LVD module is enabled, the circuitry

requires some time to stabilize. The IRVST bit is a

read-only bit and is used to indicate when the circuit is

stable. The module can only generate an interrupt after

the circuit is stable and IRVST is set.

18.1 Operation

When the LVD module is enabled, a comparator uses

an internally generated reference voltage as the set

point. The set point is compared with the trip point,

where each node in the resistor divider represents a

trip point voltage. The “trip point” voltage is the voltage

level at which the device detects a low-voltage event

depending on the configuration of the module. When

the supply voltage is equal to the trip point, the voltage

tapped off of the resistor array is equal to the internal

reference voltage generated by the voltage reference

module. The comparator then generates an interrupt

signal by setting the LVDIF bit.

The trip point voltage is software programmable to any 1 of

15 values. The trip point is selected by programming the

LVDL3:LVDL0 bits (LVDCON<3:0>).

FIGURE 18-1: LVD MODULE BLOCK DIAGRAM

Set

VDD

16-to-1 MUX

LVDEN

LVDCON

LVDL3:LVDL0

LVDIF

LVDEN

BORENx

Internal Voltage

Reference

PIC18F1230/1330

18.2 LVD Setup

The following steps are needed to set up the LVD

module:

1. Disable the module by clearing the LVDEN bit

(LVDCON<4>).

2. Write the value to the LVDL3:LVDL0 bits that

selects the desired LVD trip point.

3. Enable the LVD module by setting the LVDEN

bit.

4. Clear the LVD interrupt flag (PIR2<2>) which

may have been set from a previous interrupt.

5. Enable the LVD interrupt, if interrupts are

desired, by setting the LVDIE and GIE bits

(PIE2<2> and INTCON<7>). An interrupt will not

be generated until the IRVST bit is set.

18.3 Current Consumption

When the module is enabled, the LVD comparator and

voltage divider are enabled and will consume static cur-

rent. The total current consumption, when enabled, is

specified in electrical specification parameter D022B.

Depending on the application, the LVD module does

not need to be operating constantly. To decrease the

current requirements, the LVD circuitry may only need

to be enabled for short periods where the voltage is

checked. After doing the check, the LVD module may

be disabled.

18.4 LVD Start-up Time

The internal reference voltage of the LVD module,

specified in electrical specification parameter D420,

may be used by other internal circuitry, such as the

programmable Brown-out Reset. If the LVD or other

circuits using the voltage reference are disabled to

lower the device’s current consumption, the reference

voltage circuit will require time to become stable before

a low-voltage condition can be reliably detected. This

start-up time, TIRVST, is an interval that is independent

of device clock speed. It is specified in electrical

specification parameter 36.

The LVD interrupt flag is not enabled until TIRVST has

expired and a stable reference voltage is reached. For

this reason, brief excursions beyond the set point may

not be detected during this interval (refer to Figure 18-2).

FIGURE 18-2: LOW-VOLTAGE DETECT OPERATION

VLVD

VDD

LVDIF

VLVD

VDD

Enable LVD

TIRVST

LVDIF may not be set

Enable LVD

LVDIF

LVDIF cleared in software

LVDIF cleared in software,

CASE 1:

CASE 2:

LVDIF remains set since LVD condition still exists

TIRVST

Internal reference is stable

IRVST

PIC18F1230/1330

18.5 Applications

In many applications, the ability to detect a drop below

a particular threshold is desirable.

For general battery applications, Figure 18-3 shows a

possible voltage curve. Over time, the device voltage

decreases. When the device voltage reaches voltage

VA, the LVD logic generates an interrupt at time TA. The

interrupt could cause the execution of an ISR, which

would allow the application to perform “housekeeping

tasks” and perform a controlled shutdown before the

device voltage exits the valid operating range at TB.

The LVD, thus, would give the application a time win-

dow, represented by the difference between TA and TB,

to safely exit.

FIGURE 18-3: TYPICAL LOW-VOLTAGE

DETECT APPLICATION

18.6 Operation During Sleep

When enabled, the LVD circuitry continues to operate

during Sleep. If the device voltage crosses the trip

point, the LVDIF bit will be set and the device will wake-

up from Sleep. Device execution will continue from the

interrupt vector address if interrupts have been globally

enabled.

18.7 Effects of a Reset

A device Reset forces all registers to their Reset state.

This forces the LVD module to be turned off.

TABLE 18-1: REGISTERS ASSOCIATED WITH LOW-VOLTAGE DETECT MODULE

Time

Voltage

TATB

VA = LVD trip point

VB = Minimum valid device

operating voltage

Legend:

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Reset

Values

on Page:

LVDCON —— IRVST LVDEN LVDL3 LVDL2 LVDL1 LVDL0 42

INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 41

PIR2 OSCFIF — — EEIF —LVDIF——43

PIE2 OSCFIE — — EEIE —LVDIE——43

IPR2 OSCFIP — — EEIP —LVDIP——43

Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the LVD module.

PIC18F1230/1330

19.0 SPECIAL FEATURES OF

THE CPU

PIC18F1230/1330 devices include several features

intended to maximize reliability and minimize cost

through elimination of external components. These

are:

• Oscillator Selection

• Resets:

- Power-on Reset (POR)

- Power-up Timer (PWRT)

- Oscillator Start-up Timer (OST)

- Brown-out Reset (BOR)

• Interrupts

• Watchdog Timer (WDT)

• Fail-Safe Clock Monitor

• Two-Speed Start-up

• Code Protection

• ID Locations

• In-Circuit Serial Programming

The oscillator can be configured for the application

depending on frequency, power, accuracy and cost. All

of the options are discussed in detail in Section 2.0

“Oscillator Configurations”.

A complete discussion of device Resets and interrupts

is available in previous sections of this data sheet.

In addition to their Power-up and Oscillator Start-up

Timers provided for Resets, PIC18F1230/1330 devices

have a Watchdog Timer, which is either permanently

enabled via the Configuration bits or software

controlled (if configured as disabled).

The inclusion of an internal RC oscillator also provides

the additional benefits of a Fail-Safe Clock Monitor

(FSCM) and Two-Speed Start-up. FSCM provides for

background monitoring of the peripheral clock and

automatic switchover in the event of its failure. Two-

Speed Start-up enables code to be executed almost

immediately on start-up while the primary clock source

completes its start-up delays.

All of these features are enabled and configured by

setting the appropriate Configuration register bits.

19.1 Configuration Bits

The Configuration bits can be programmed (read as

‘0’) or left unprogrammed (read as ‘1’) to select various

device configurations. These bits are mapped starting

at program memory location 300000h.

The user will note that address 300000h is beyond the

user program memory space. In fact, it belongs to the

configuration memory space (300000h-3FFFFFh) which

can only be accessed using table reads and table writes.

Programming the Configuration registers is done in a

manner similar to programming the Flash memory. The

WR bit in the EECON1 register starts a self-timed write

to the Configuration register. In normal operation

mode, a TBLWT instruction with the TBLPTR pointing to

the Configuration register sets up the address and data

for the Configuration register write. Setting the WR bit

starts a long

write to the Configuration register. The

Configuration registers are written a byte at a time. To

write or erase a configuration cell, a TBLWT instruction

can write a ‘1’ or a ‘0’ into the cell. For additional details

on Flash programming, refer to Section 6.5 “Writing

to Flash Program Memory”.

TABLE 19-1: CONFIGURATION BITS AND DEVICE IDs

File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Default/

Unprogrammed

Value

300001h CONFIG1H IESO FCMEN —— FOSC3 FOSC2 FOSC1 FOSC0 00-- 0111

300002h CONFIG2L — — — BORV1 BORV0 BOREN1 BOREN0 PWRTEN ---1 1111

300003h CONFIG2H — — — WDTPS3 WDTPS2 WDTPS1 WDTPS0 WDTEN ---1 1111

300004h CONFIG3L — — — — HPOL LPOL PWMPIN —---- 111-

300005h CONFIG3H MCLRE — — —T1OSCMX——FLTAMX1--- 0--1

300006h CONFIG4L BKBUG XINST BBSIZ1 BBSIZ0 — — —STVREN1000 ---1

300008h CONFIG5L — — — — — —CP1CP0---- --11

300009h CONFIG5H CPD CPB — — — — — — 11-- ----

30000Ah CONFIG6L — — — — — — WRT1 WRT0 ---- --11

30000Bh CONFIG6H WRTD WRTB WRTC — — — — — 111- ----

30000Ch CONFIG7L — — — — — — EBTR1 EBTR0 ---- --11

30000Dh CONFIG7H —EBTRB— — — — — — -1-- ----

3FFFFEh DEVID1(1) DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 See Table 19-2

3FFFFFh DEVID2(1) DEV10 DEV9 DEV8 DEV7 DEEV6 DEV5 DEV4 DEV3 See Table 19-2

Legend: - = unimplemented, read as ‘0’.Shaded cells are unimplemented, read as ‘0’.

Note 1: DEVID registers are read-only and cannot be programmed by the user.

PIC18F1230/1330

R/P-0 R/P-0 U-0 U-0 R/P-0 R/P-1 R/P-1 R/P-1

IESO FCMEN —— FOSC3 FOSC2 FOSC1 FOSC0

bit 7 bit 0

Legend:

R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7 IESO: Internal/External Oscillator Switchover bit

1 = Oscillator Switchover mode enabled

0 = Oscillator Switchover mode disabled

bit 6 FCMEN: Fail-Safe Clock Monitor Enable bit

1 = Fail-Safe Clock Monitor enabled

0 = Fail-Safe Clock Monitor disabled

bit 5-4 Unimplemented: Read as ‘0’

bit 3-0 FOSC3:FOSC0: Oscillator Selection bits

11xx = External RC oscillator, CLKO function on RA6

101x = External RC oscillator, CLKO function on RA6

1001 = Internal oscillator block, CLKO function on RA6, port function on RA7

1000 = Internal oscillator block, port function on RA6 and RA7

0111 = External RC oscillator, port function on RA6

0110 = HS oscillator, PLL enabled (Clock Frequency = 4 x FOSC1)

0101 = EC oscillator, port function on RA6

0100 = EC oscillator, CLKO function on RA6

0011 = External RC oscillator, CLKO function on RA6

0010 = HS oscillator

0001 = XT oscillator

0000 = LP oscillator

PIC18F1230/1330

U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1

— — —BORV1

(1) BORV0(1) BOREN1(2) BOREN0(2) PWRTEN(2)

bit 7 bit 0

Legend:

R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7-5 Unimplemented: Read as ‘0’

bit 4-3 BORV1:BORV0: Brown-out Reset Voltage bits(1)

11 = Minimum setting

•

00 = Maximum setting

bit 2-1 BOREN1:BOREN0: Brown-out Reset Enable bits(2)

11 = Brown-out Reset enabled in hardware only (SBOREN is disabled)

10 = Brown-out Reset enabled in hardware only and disabled in Sleep mode (SBOREN is disabled)

01 = Brown-out Reset enabled and controlled by software (SBOREN is enabled)

00 = Brown-out Reset disabled in hardware and software

bit 0 PWRTEN: Power-up Timer Enable bit(2)

1 = PWRT disabled

0 = PWRT enabled

Note 1: See Section 22.1 “DC Characteristics” for the specifications.

2: The Power-up Timer is decoupled from Brown-out Reset, allowing these features to be independently

controlled.

PIC18F1230/1330

U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1

— — — WDTPS3 WDTPS2 WDTPS1 WDTPS0 WDTEN

bit 7 bit 0

Legend:

R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7-5 Unimplemented: Read as ‘0’

bit 4-1 WDTPS3:WDTPS0: Watchdog Timer Postscale Select bits

1111 = 1:32,768

1110 = 1:16,384

1101 = 1:8,192

1100 = 1:4,096

1011 = 1:2,048

1010 = 1:1,024

1001 = 1:512

1000 = 1:256

0111 = 1:128

0110 = 1:64

0101 = 1:32

0100 = 1:16

0011 = 1:8

0010 = 1:4

0001 = 1:2

0000 = 1:1

bit 0 WDTEN: Watchdog Timer Enable bit

1 = WDT enabled

0 = WDT disabled (control is placed on the SWDTEN bit)

PIC18F1230/1330

U-0 U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 U-0

— — — —HPOL

(1) LPOL(1) PWMPIN —

bit 7 bit 0

Legend:

R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7-4 Unimplemented: Read as ‘0’

bit 3 HPOL: High Side Transistors Polarity bit (Odd PWM Output Polarity Control bit)(1)

1 = PWM1, PWM3 and PWM5 are active-high (default)

0 = PWM1, PWM3 and PWM5 are active-low

bit 2 LPOL: Low Side Transistors Polarity bit (Even PWM Output Polarity Control bit)(1)

1 = PWM0, PWM2 and PWM4 are active-high (default)

0 = PWM0, PWM2 and PWM4 are active-low

bit 2 PWMPIN: PWM Output Pins Reset State Control bit

1 = PWM outputs disabled upon Reset

0 = PWM outputs drive active states upon Reset(2)

bit 0 Unimplemented: Read as ‘0’

Note 1: Polarity control bits, HPOL and LPOL, define PWM signal output active and inactive states, PWM states

generated by the Fault inputs or PWM manual override.

2: When PWMPIN = 0, PWMEN<2:0> = 100. PWM output polarity is defined by HPOL and LPOL.

PIC18F1230/1330

R/P-1 U-0 U-0 U-0 R/P-0 U-0 U-0 R/P-1

MCLRE — — —T1OSCMX ——FLTAMX

bit 7 bit 0

Legend:

R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7 MCLRE: MCLR Pin Enable bit

1 =MCLR

pin enabled, RA5 input pin disabled

0 = RA5 input pin enabled, MCLR pin disabled

bit 6-4 Unimplemented: Read as ‘0’

bit 3 T1OSCMX: T1OSO/T1CKI MUX bit

1 = T1OSO/T1CKI pin resides on RA6

0 = T1OSO/T1CKI pin resides on RB2

bit 2-1 Unimplemented: Read as ‘0’

bit 0 FLTAMX: FLTA MUX bit

1 = FLTA is muxed onto RA5

0 = FLTA is muxed onto RA7

PIC18F1230/1330

R/P-1 R/P-0 R/P-0 R/P-0 U-0 U-0 U-0 R/P-1

BKBUG XINST BBSIZ1 BBSIZ0 — — —STVREN

bit 7 bit 0

Legend:

R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7 BKBUG: Background Debugger Enable bit

1 = Background debugger disabled, RB6 and RB7 configured as general purpose I/O pins

0 = Background debugger enabled, RB6 and RB7 are dedicated to In-Circuit Debug

bit 6 XINST: Extended Instruction Set Enable bit

1 = Instruction set extension and Indexed Addressing mode enabled

0 = Instruction set extension and Indexed Addressing mode disabled

bit 5-4 BBSIZ<1:0>: Boot Block Size Select bits

For PIC18F1330 device:

11 = 1 kW Boot Block size

10 = 1 kW Boot Block size

01 = 512W Boot Block size

00 = 256W Boot Block size

For PIC18F1230 device:

11 = 512W Boot Block size

10 = 512W Boot Block size

01 = 512W Boot Block size

00 = 256W Boot Block size

bit 3-1 Unimplemented: Read as ‘0’

bit 0 STVREN: Stack Overflow/Underflow Reset Enable bit

1 = Reset on stack overflow/underflow enabled

0 = Reset on stack overflow/underflow disabled

PIC18F1230/1330

U-0 U-0 U-0 U-0 U-0 U-0 R/C-1 R/C-1

— — — — — —CP1CP0

bit 7 bit 0

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7-2 Unimplemented: Read as ‘0’

bit 1 CP1: Code Protection bit (Block 1 Code Memory Area)

1 = Block 1 is not code-protected

0 = Block 1 is code-protected

bit 0 CP0: Code Protection bit (Block 0 Code Memory Area)

1 = Block 0 is not code-protected

0 = Block 0 is code-protected

R/C-1 R/C-1 U-0 U-0 U-0 U-0 U-0 U-0

CPD CPB — — — — — —

bit 7 bit 0

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7 CPD: Code Protection bit (Data EEPROM)

1 = Data EEPROM is not code-protected

0 = Data EEPROM is code-protected

bit 6 CPB: Code Protection bit (Boot Block Memory Area)

1 = Boot Block is not code-protected

0 = Boot Block is code-protected

bit 5-0 Unimplemented: Read as ‘0’

PIC18F1230/1330

U-0 U-0 U-0 U-0 U-0 U-0 R/C-1 R/C-1

— — — — — —WRT1WRT0

bit 7 bit 0

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7-2 Unimplemented: Read as ‘0’

bit 1 WRT1: Write Protection bit (Block 1 Code Memory Area)

1 = Block 1 is not write-protected

0 = Block 1 is write-protected

bit 0 WRT0: Write Protection bit (Block 0 Code Memory Area)

1 = Block 0 is not write-protected

0 = Block 0 is write-protected

R/C-1 R/C-1 R-1 U-0 U-0 U-0 U-0 U-0

WRTD WRTB WRTC(1) — — — — —

bit 7 bit 0

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7 WRTD: Write Protection bit (Data EEPROM)

1 = Data EEPROM is not write-protected

0 = Data EEPROM is write-protected

bit 6 WRTB: Write Protection bit (Boot Block Memory Area)

1 = Boot Block is not write-protected

0 = Boot Block is write-protected

bit 5 WRTC: Write Protection bit (Configuration Registers)(1)

1 = Configuration registers are not write-protected

0 = Configuration registers are write-protected

bit 4-0 Unimplemented: Read as ‘0’

Note 1: This bit is read-only in normal execution mode; it can be written only in Program mode.

PIC18F1230/1330

U-0 U-0 U-0 U-0 U-0 U-0 R/C-1 R/C-1

— — — — — — EBTR1 EBTR0

bit 7 bit 0

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7-2 Unimplemented: Read as ‘0’

bit 1 EBTR1: Table Read Protection bit (Block 1 Code Memory Area)

1 = Block 1 is not protected from table reads executed in other blocks

0 = Block 1 is protected from table reads executed in other blocks

bit 0 EBTR0: Table Read Protection bit (Block 0 Code Memory Area)

1 = Block 0 is not protected from table reads executed in other blocks

0 = Block 0 is protected from table reads executed in other blocks

U-0 R/C-1 U-0 U-0 U-0 U-0 U-0 U-0

— EBTRB — — — — — —

bit 7 bit 0

Legend:

R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7 Unimplemented: Read as ‘0’

bit 6 EBTRB: Table Read Protection bit (Boot Block Memory Area)

1 = Boot Block is not protected from table reads executed in other blocks

0 = Boot Block is protected from table reads executed in other blocks

bit 5-0 Unimplemented: Read as ‘0’

PIC18F1230/1330

RRRRRRRR

DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0

bit 7 bit 0

Legend:

R = Read-only bit P = Programmable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7-5 DEV2:DEV0: Device ID bits

These bits are used with the DEV10:DEV3 bits in the DEVID2 register to identify part number.

bit 4-0 REV3:REV0: Revision ID bits

These bits are used to indicate the device revision.

RRRRRRRR

DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3

bit 7 bit 0

Legend:

R = Read-only bit P = Programmable bit U = Unimplemented bit, read as ‘0’

-n = Value when device is unprogrammed u = Unchanged from programmed state

bit 7-0 DEV10:DEV3: Device ID bits

These bits are used with the DEV2:DEV0 bits in the DEVID1 register to identify part number.

PIC18F1230/1330

19.2 Watchdog Timer (WDT)

For PIC18F1230/1330 devices, the WDT is driven by

the INTRC source. When the WDT is enabled, the

clock source is also enabled. The nominal WDT period

is 4 ms and has the same stability as the INTRC

oscillator.

The 4 ms period of the WDT is multiplied by a 16-bit

postscaler. Any output of the WDT postscaler is

selected by a multiplexer, controlled by bits in Configu-

ration Register 2H. Available periods range from 4 ms

to 131.072 seconds (2.18 minutes). The WDT and

postscaler are cleared when any of the following events

occur: a SLEEP or CLRWDT instruction is executed, the

IRCF bits (OSCCON<6:4>) are changed or a clock

failure has occurred.

19.2.1 CONTROL REGISTER

readable and writable register which contains a control

bit that allows software to override the WDT enable

Configuration bit, but only if the Configuration bit has

disabled the WDT.

FIGURE 19-1: WDT BLOCK DIAGRAM

Note 1: The CLRWDT and SLEEP instructions

clear the WDT and postscaler counts

when executed.

2: Changing the setting of the IRCF bits

(OSCCON<6:4>) clears the WDT and

postscaler counts.

3: When a CLRWDT instruction is executed,

the postscaler count will be cleared.

INTRC Source

WDT

Wake-up from

Reset

WDT Counter

Programmable Postscaler

1:1 to 1:32,768

Enable WDT

WDTPS<3:0>

SWDTEN

WDTEN

CLRWDT

Power-Managed

Reset

All Device Resets

Sleep

÷128

Change on IRCF bits

Modes

PIC18F1230/1330

TABLE 19-2: SUMMARY OF WATCHDOG TIMER REGISTERS

U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-0

— — — — — — —SWDTEN

(1)

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

bit 7-1 Unimplemented: Read as ‘0’

bit 0 SWDTEN: Software Controlled Watchdog Timer Enable bit(1)

1 = Watchdog Timer is on

0 = Watchdog Timer is off

Note 1: This bit has no effect if the Configuration bit, WDTEN, is enabled.

Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Reset

Values

on Page:

RCON IPEN SBOREN(1) —RI TO PD POR BOR 42

WDTCON — — — — — — —SWDTEN

(2) 42

Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Watchdog Timer.

Note 1: The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise, it is

disabled and reads as ‘0’. See Section 4.4 “Brown-out Reset (BOR)”.

2: This bit has no effect if the Configuration bit, WDTEN, is enabled.

PIC18F1230/1330

19.3 Two-Speed Start-up

The Two-Speed Start-up feature helps to minimize the

latency period from oscillator start-up to code execution

by allowing the microcontroller to use the INTOSC

oscillator as a clock source until the primary clock

source is available. It is enabled by setting the IESO

Configuration bit.

Two-Speed Start-up should be enabled only if the

primary oscillator mode is LP, XT, HS or HSPLL

(crystal-based modes). Other sources do not require

an OST start-up delay; for these, Two-Speed Start-up

should be disabled.

When enabled, Resets and wake-ups from Sleep mode

cause the device to configure itself to run from the

internal oscillator block as the clock source, following

the time-out of the Power-up Timer, after a Power-on

Reset is enabled. This allows almost immediate code

execution while the primary oscillator starts and the

OST is running. Once the OST times out, the device

automatically switches to PRI_RUN mode.

To use a higher clock speed on wake-up, the INTOSC

or postscaler clock sources can be selected to provide

a higher clock speed by setting bits, IRCF2:IRCF0,

immediately after Reset. For wake-ups from Sleep, the

INTOSC or postscaler clock sources can be selected

by setting the IRCF2:IRCF0 bits prior to entering Sleep

mode.

In all other power-managed modes, Two-Speed Start-up

is not used. The device will be clocked by the currently

selected clock source until the primary clock source

becomes available. The setting of the IESO bit is

ignored.

19.3.1 SPECIAL CONSIDERATIONS FOR

USING TWO-SPEED START-UP

While using the INTOSC oscillator in Two-Speed

Start-up, the device still obeys the normal command

sequences for entering power-managed modes,

including multiple SLEEP instructions (refer to

Section 3.1.4 “Multiple Sleep Commands”). In

practice, this means that user code can change the

SCS1:SCS0 bit settings or issue SLEEP instructions

before the OST times out. This would allow an applica-

tion to briefly wake-up, perform routine “housekeeping”

tasks and return to Sleep before the device starts to

operate from the primary oscillator.

User code can also check if the primary clock source is

currently providing the device clocking by checking the

status of the OSTS bit (OSCCON<3>). If the bit is set,

the primary oscillator is providing the clock. Otherwise,

the internal oscillator block is providing the clock during

wake-up from Reset or Sleep mode.

FIGURE 19-2: TIMING TRANSITION FOR TWO-SPEED START-UP (INTOSC TO HSPLL)

Q1 Q3 Q4

OSC1

Peripheral

Program PC PC + 2

INTOSC

PLL Clock

PC + 6

Output

Q3 Q4 Q1

CPU Clock

PC + 4

Clock

Counter

Q2 Q2 Q3

Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.

2: Clock transition typically occurs within 2-4 TOSC.

Wake from Interrupt Event

TPLL(1)

12 n-1n

Clock

OSTS bit Set

Transition(2)

Multiplexer

TOST(1)

PIC18F1230/1330

19.4 Fail-Safe Clock Monitor

The Fail-Safe Clock Monitor (FSCM) allows the

microcontroller to continue operation in the event of an

external oscillator failure by automatically switching the

device clock to the internal oscillator block. The FSCM

function is enabled by setting the FCMEN Configuration

bit.

When FSCM is enabled, the INTRC oscillator runs at

all times to monitor clocks to peripherals and provide a

backup clock in the event of a clock failure. Clock

monitoring (shown in Figure 19-3) is accomplished by

creating a sample clock signal, which is the INTRC

output divided by 64. This allows ample time between

FSCM sample clocks for a peripheral clock edge to

occur. The peripheral device clock and the sample

clock are presented as inputs to the Clock Monitor latch

(CM). The CM is set on the falling edge of the device

clock source, but cleared on the rising edge of the

sample clock.

FIGURE 19-3: FSCM BLOCK DIAGRAM

Clock failure is tested for on the falling edge of the

sample clock. If a sample clock falling edge occurs

while CM is still set, a clock failure has been detected

(Figure 19-4). This causes the following:

• The FSCM generates an oscillator fail interrupt by

setting bit, OSCFIF (PIR2<7>).

• The device clock source is switched to the internal

oscillator block (OSCCON is not updated to show

the current clock source – this is the fail-safe

condition).

•The WDT is reset.

During switchover, the postscaler frequency from the

internal oscillator block may not be sufficiently stable for

timing sensitive applications. In these cases, it may be

desirable to select another clock configuration and enter

an alternate power-managed mode. This can be done to

attempt a partial recovery or execute a controlled shut-

down. See Section 3.1.4 “Multiple Sleep Commands”

and Section 19.3.1 “Special Considerations for

Using Two-Speed Start-up” for more details.

To use a higher clock speed on wake-up, the INTOSC

or postscaler clock sources can be selected to provide

a higher clock speed by setting bits, IRCF2:IRCF0,

immediately after Reset. For wake-ups from Sleep, the

INTOSC or postscaler clock sources can be selected

by setting the IRCF2:IRCF0 bits prior to entering Sleep

mode.

The FSCM will detect failures of the primary or

secondary clock sources only. If the internal oscillator

block fails, no failure would be detected, nor would any

action be possible.

19.4.1 FSCM AND THE WATCHDOG TIMER

Both the FSCM and the WDT are clocked by the

INTRC oscillator. Since the WDT operates with a

separate divider and counter, disabling the WDT has

no effect on the operation of the INTRC oscillator when

the FSCM is enabled.

As already noted, the clock source is switched to the

INTOSC clock when a clock failure is detected.

Depending on the frequency selected by the

IRCF2:IRCF0 bits, this may mean a substantial change

in the speed of code execution. If the WDT is enabled

with a small prescale value, a decrease in clock speed

allows a WDT time-out to occur and a subsequent

device Reset. For this reason, fail-safe clock events

also reset the WDT and postscaler, allowing it to start

timing from when execution speed was changed and

decreasing the likelihood of an erroneous time-out.

19.4.2 EXITING FAIL-SAFE OPERATION

The fail-safe condition is terminated by either a device

Reset or by entering a power-managed mode. On

Reset, the controller starts the primary clock source

specified in Configuration Register 1H (with any

required start-up delays that are required for the

oscillator mode, such as the OST or PLL timer). The

INTOSC multiplexer provides the device clock until the

primary clock source becomes ready (similar to a Two-

Speed Start-up). The clock source is then switched to

the primary clock (indicated by the OSTS bit in the

OSCCON register becoming set). The Fail-Safe Clock

Monitor then resumes monitoring the peripheral clock.

The primary clock source may never become ready

during start-up. In this case, operation is clocked by the

INTOSC multiplexer. The OSCCON register will remain

in its Reset state until a power-managed mode is

entered.

Peripheral

INTRC ÷ 64

(32 μs) 488 Hz

(2.048 ms)

Clock Monitor

Latch (CM)

(edge-triggered)

Clock

Failure

Detected

Source

Clock

PIC18F1230/1330

FIGURE 19-4: FSCM TIMING DIAGRAM

19.4.3 FSCM INTERRUPTS IN

POWER-MANAGED MODES

By entering a power-managed mode, the clock multi-

plexer selects the clock source selected by the OSCCON

managed clock source resumes in the power-managed

mode.

If an oscillator failure occurs during power-managed

operation, the subsequent events depend on whether

or not the oscillator failure interrupt is enabled. If

enabled (OSCFIF = 1), code execution will be clocked

by the INTOSC multiplexer. An automatic transition

back to the failed clock source will not occur.

If the interrupt is disabled, subsequent interrupts while

in Idle mode will cause the CPU to begin executing

instructions while being clocked by the INTOSC

source.

19.4.4 POR OR WAKE FROM SLEEP

The FSCM is designed to detect oscillator failure at any

point after the device has exited Power-on Reset

(POR) or low-power Sleep mode. When the primary

device clock is EC, RC or INTRC modes, monitoring

can begin immediately following these events.

For oscillator modes involving a crystal or resonator

(HS, HSPLL, LP or XT), the situation is somewhat

different. Since the oscillator may require a start-up

time considerably longer than the FCSM sample clock

time, a false clock failure may be detected. To prevent

this, the internal oscillator block is automatically

configured as the device clock and functions until the

primary clock is stable (the OST and PLL timers have

timed out). This is identical to Two-Speed Start-up

mode. Once the primary clock is stable, the INTRC

returns to its role as the FSCM source.

As noted in Section 19.3.1 “Special Considerations

for Using Two-Speed Start-up”, it is also possible to

select another clock configuration and enter an

alternate power-managed mode while waiting for the

primary clock to become stable. When the new power-

managed mode is selected, the primary clock is

disabled.

OSCFIF

CM Output

Device

Clock

Output

Sample Clock

Failure

Detected

Oscillator

Failure

Note: The device clock is normally at a much higher frequency than the sample clock. The relative frequencies in

this example have been chosen for clarity.

(Q)

CM Test CM Test CM Test

Note: The same logic that prevents false oscilla-

tor failure interrupts on POR, or wake from

Sleep, will also prevent the detection of

the oscillator’s failure to start at all follow-

ing these events. This can be avoided by

monitoring the OSTS bit and using a

timing routine to determine if the oscillator

is taking too long to start. Even so, no

oscillator failure interrupt will be flagged.

PIC18F1230/1330

19.5 Program Verification and

Code Protection

The overall structure of the code protection on the

PIC18 Flash devices differs significantly from other

PIC® devices.

The user program memory is divided into three blocks.

One of these is a Boot Block of variable size (maximum

2 Kbytes). The remainder of the memory is divided into

two blocks on binary boundaries.

Each of the three blocks has three code protection bits

associated with them. They are:

• Code-Protect bit (CPx)

• Write-Protect bit (WRTx)

• External Block Table Read bit (EBTRx)

Figure 19-5 shows the program memory organization

for 4 and 8-Kbyte devices and the specific code

protection bit associated with each block. The actual

locations of the bits are summarized in Table 19-3.

FIGURE 19-5: CODE-PROTECTED PROGRAM MEMORY FOR PIC18F1230/1330

TABLE 19-3: SUMMARY OF CODE PROTECTION REGISTERS

File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

300008h CONFIG5L ——————CP1CP0

300009h CONFIG5H CPD CPB — — — — — —

30000Ah CONFIG6L ——————WRT1WRT0

30000Bh CONFIG6H WRTD WRTB WRTC — — — — —

30000Ch CONFIG7L —————— EBTR1 EBTR0

30000Dh CONFIG7H — EBTRB — — — — — —

Legend: Shaded cells are unimplemented.

MEMORY SIZE/DEVICE

Block Code Protection

Controlled By:

4Kbytes

(PIC18F1230)

8Kbytes

(PIC18F1330)

Address

Range

Boot Block

000000h

0003FFh CPB, WRTB, EBTRB

Block 0

000400h

0007FFh

CP0, WRT0, EBTR0

Block 1 Block 0

000800h

000FFFh

CP1, WRT1, EBTR1

Unimplemented

Read ‘0’s

Block 1

001000h

001FFFh

CP2, WRT2, EBTR2

Unimplemented

Read ‘0’s

Unimplemented

Read ‘0’s

002000h

1FFFFFh

(Unimplemented Memory Space)

PIC18F1230/1330

19.5.1 PROGRAM MEMORY

CODE PROTECTION

The program memory may be read to or written from

any location using the table read and table write

instructions. The Device ID may be read with table

reads. The Configuration registers may be read and

written with the table read and table write instructions.

In normal execution mode, the CPx bits have no direct

effect. CPx bits inhibit external reads and writes. A

block of user memory may be protected from table

writes if the WRTx Configuration bit is ‘0’. The EBTRx

bits control table reads. For a block of user memory

with the EBTRx bit set to ‘0’, a table read instruction

that executes from within that block is allowed to read.

A table read instruction that executes from a location

outside of that block is not allowed to read and will result

in reading ‘0’s. Figures 19-6 through 19-8 illustrate table

write and table read protection.

FIGURE 19-6: TABLE WRITE (WRTx) DISALLOWED

Note: Code protection bits may only be written to

a ‘0’ from a ‘1’ state. It is not possible to

write a ‘1’ to a bit in the ‘0’ state. Code

protection bits are only set to ‘1’ by a full

chip erase or block erase function. The full

chip erase and block erase functions can

only be initiated via ICSP operation or an

external programmer.

000000h

0007FFh

000800h

000FFFh

001000h

001FFFh

WRTB, EBTRB = 11

WRT0, EBTR0 = 01

WRT1, EBTR1 = 11

TBLWT*

TBLPTR = 0008FFh

PC = 000FFEh

PC = 001800h

Results: All table writes disabled to Blockn whenever WRTx = 0.

TBLWT*

PIC18F1230/1330

FIGURE 19-7: EXTERNAL BLOCK TABLE READ (EBTRx) DISALLOWED

FIGURE 19-8: EXTERNAL BLOCK TABLE READ (EBTRx) ALLOWED

WRTB, EBTRB = 11

WRT0, EBTR0 = 10

WRT1, EBTR1 = 11

TBLRD*

TBLPTR = 0008FFh

PC = 001100h

Results: All table reads from external blocks to Blockn are disabled whenever EBTRx = 0.

TABLAT register returns a value of ‘0’.

000000h

0007FFh

000800h

000FFFh

001000h

001FFFh

WRTB, EBTRB = 11

WRT0, EBTR0 = 10

WRT1, EBTR1 = 11

TBLRD*

TBLPTR = 0008FFh

PC = 000FFEh

Results: Table reads permitted within Blockn, even when EBTRBx = 0.

TABLAT register returns the value of the data at the location TBLPTR.

000000h

0007FFh

000800h

000FFFh

001000h

001FFFh

PIC18F1230/1330

19.5.2 DATA EEPROM

CODE PROTECTION

The entire data EEPROM is protected from external

reads and writes by two bits: CPD and WRTD. CPD

inhibits external reads and writes of data EEPROM.

WRTD inhibits internal and external writes to data

EEPROM. The CPU can always read data EEPROM

under normal operation, regardless of the protection bit

settings.

19.5.3 CONFIGURATION REGISTER

PROTECTION

The Configuration registers can be write-protected.

The WRTC bit controls protection of the Configuration

registers. In normal execution mode, the WRTC bit is

read-only. WRTC can only be written via ICSP

operation or an external programmer.

19.6 ID Locations

Eight memory locations (200000h-200007h) are

designated as ID locations, where the user can store

checksum or other code identification numbers. These

locations are both readable and writable during normal

execution through the TBLRD and TBLWT instructions

or during program/verify. The ID locations can be read

when the device is code-protected.

19.7 In-Circuit Serial Programming

PIC18F1230/1330 microcontrollers can be serially

programmed while in the end application circuit. This is

simply done with two lines for clock and data and three

other lines for power, ground and the programming

voltage. This allows customers to manufacture boards

with unprogrammed devices and then program the

microcontroller just before shipping the product. This

also allows the most recent firmware or a custom

firmware to be programmed.

19.8 In-Circuit Debugger

When the BKBUG Configuration bit is programmed to

a ‘0’, the In-Circuit Debugger functionality is enabled.

This function allows simple debugging functions when

used with MPLAB® IDE. When the microcontroller has

this feature enabled, some resources are not available

for general use. Table 19-4 shows which resources are

required by the background debugger.

TABLE 19-4: DEBUGGER RESOURCES

To use the In-Circuit Debugger function of the microcon-

troller, the design must implement In-Circuit Serial

Programming connections to MCLR/VPP/RA5/FLTA,

VDD, VSS, RB7/PWM5/PGD and RB6/PWM4/PGC. This

will interface to the In-Circuit Debugger module available

from Microchip or one of the third party development tool

companies.

19.9 Single-Supply ICSP Programming

The PIC18F1230/1330 device family does not support

Low-Voltage ICSP Programming or LVP. This device

family can only be programmed using high-voltage ICSP

programming. For more details, refer to the

“PIC18F1230/1330 Flash Microcontroller Programming

Specification”

(DS39752).

Memory that is not code-protected can be erased using

either a block erase, or erased row by row, then written

at any specified VDD. If code-protected memory is to be

erased, a block erase is required.

I/O pins: RB6, RB7

Stack: 2 levels

Program Memory: 512 bytes

Data Memory: 10 bytes

PIC18F1230/1330

20.0 DEVELOPMENT SUPPORT

The PIC® microcontrollers are supported with a full

range of hardware and software development tools:

• Integrated Development Environment

- MPLAB® IDE Software

• Assemblers/Compilers/Linkers

- MPASMTM Assembler

- MPLAB C18 and MPLAB C30 C Compilers

-MPLINK

TM Object Linker/

MPLIBTM Object Librarian

- MPLAB ASM30 Assembler/Linker/Library

• Simulators

- MPLAB SIM Software Simulator

•Emulators

- MPLAB ICE 2000 In-Circuit Emulator

- MPLAB REAL ICE™ In-Circuit Emulator

• In-Circuit Debugger

- MPLAB ICD 2

• Device Programmers

- PICSTART® Plus Development Programmer

- MPLAB PM3 Device Programmer

- PICkit™ 2 Development Programmer

• Low-Cost Demonstration and Development

Boards and Evaluation Kits

20.1 MPLAB Integrated Development

Environment Software

The MPLAB IDE software brings an ease of software

development previously unseen in the 8/16-bit micro-

controller market. The MPLAB IDE is a Windows®

operating system-based application that contains:

• A single graphical interface to all debugging tools

- Simulator

- Programmer (sold separately)

- Emulator (sold separately)

- In-Circuit Debugger (sold separately)

• A full-featured editor with color-coded context

• A multiple project manager

• Customizable data windows with direct edit of

contents

• High-level source code debugging

• Visual device initializer for easy register

initialization

• Mouse over variable inspection

• Drag and drop variables from source to watch

windows

• Extensive on-line help

• Integration of select third party tools, such as

HI-TECH Software C Compilers and IAR

C Compilers

The MPLAB IDE allows you to:

• Edit your source files (either assembly or C)

• One touch assemble (or compile) and download

to PIC MCU emulator and simulator tools

(automatically updates all project information)

• Debug using:

- Source files (assembly or C)

- Mixed assembly and C

- Machine code

MPLAB IDE supports multiple debugging tools in a

single development paradigm, from the cost-effective

simulators, through low-cost in-circuit debuggers, to

full-featured emulators. This eliminates the learning

curve when upgrading to tools with increased flexibility

and power.

PIC18F1230/1330

20.2 MPASM Assembler

The MPASM Assembler is a full-featured, universal

macro assembler for all PIC MCUs.

The MPASM Assembler generates relocatable object

files for the MPLINK Object Linker, Intel® standard HEX

files, MAP files to detail memory usage and symbol

reference, absolute LST files that contain source lines

and generated machine code and COFF files for

debugging.

The MPASM Assembler features include:

• Integration into MPLAB IDE projects

• User-defined macros to streamline

assembly code

• Conditional assembly for multi-purpose

source files

• Directives that allow complete control over the

assembly process

20.3 MPLAB C18 and MPLAB C30

C Compilers

The MPLAB C18 and MPLAB C30 Code Development

Systems are complete ANSI C compilers for

Microchip’s PIC18 and PIC24 families of microcontrol-

lers and the dsPIC30 and dsPIC33 family of digital sig-

nal controllers. These compilers provide powerful

integration capabilities, superior code optimization and

ease of use not found with other compilers.

For easy source level debugging, the compilers provide

symbol information that is optimized to the MPLAB IDE

debugger.

20.4 MPLINK Object Linker/

MPLIB Object Librarian

The MPLINK Object Linker combines relocatable

objects created by the MPASM Assembler and the

MPLAB C18 C Compiler. It can link relocatable objects

from precompiled libraries, using directives from a

linker script.

The MPLIB Object Librarian manages the creation and

modification of library files of precompiled code. When

a routine from a library is called from a source file, only

the modules that contain that routine will be linked in

with the application. This allows large libraries to be

used efficiently in many different applications.

The object linker/library features include:

• Efficient linking of single libraries instead of many

smaller files

• Enhanced code maintainability by grouping

related modules together

• Flexible creation of libraries with easy module

listing, replacement, deletion and extraction

20.5 MPLAB ASM30 Assembler, Linker

and Librarian

MPLAB ASM30 Assembler produces relocatable

machine code from symbolic assembly language for

dsPIC30F devices. MPLAB C30 C Compiler uses the

assembler to produce its object file. The assembler

generates relocatable object files that can then be

archived or linked with other relocatable object files and

archives to create an executable file. Notable features

of the assembler include:

• Support for the entire dsPIC30F instruction set

• Support for fixed-point and floating-point data

• Command line interface

• Rich directive set

• Flexible macro language

• MPLAB IDE compatibility

20.6 MPLAB SIM Software Simulator

The MPLAB SIM Software Simulator allows code

development in a PC-hosted environment by simulat-

ing the PIC MCUs and dsPIC® DSCs on an instruction

level. On any given instruction, the data areas can be

examined or modified and stimuli can be applied from

a comprehensive stimulus controller. Registers can be

logged to files for further run-time analysis. The trace

buffer and logic analyzer display extend the power of

the simulator to record and track program execution,

actions on I/O, most peripherals and internal registers.

The MPLAB SIM Software Simulator fully supports

symbolic debugging using the MPLAB C18 and

MPLAB C30 C Compilers, and the MPASM and

MPLAB ASM30 Assemblers. The software simulator

offers the flexibility to develop and debug code outside

of the hardware laboratory environment, making it an

excellent, economical software development tool.

PIC18F1230/1330

20.7 MPLAB ICE 2000

High-Performance

In-Circuit Emulator

The MPLAB ICE 2000 In-Circuit Emulator is intended

to provide the product development engineer with a

complete microcontroller design tool set for PIC

microcontrollers. Software control of the MPLAB ICE

2000 In-Circuit Emulator is advanced by the MPLAB

Integrated Development Environment, which allows

editing, building, downloading and source debugging

from a single environment.

The MPLAB ICE 2000 is a full-featured emulator

system with enhanced trace, trigger and data monitor-

ing features. Interchangeable processor modules allow

the system to be easily reconfigured for emulation of

different processors. The architecture of the MPLAB

ICE 2000 In-Circuit Emulator allows expansion to

support new PIC microcontrollers.

The MPLAB ICE 2000 In-Circuit Emulator system has

been designed as a real-time emulation system with

advanced features that are typically found on more

expensive development tools. The PC platform and

Microsoft® Windows® 32-bit operating system were

chosen to best make these features available in a

simple, unified application.

20.8 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® and dsPIC® Flash microcontrollers with

the easy-to-use, powerful graphical user interface of the

MPLAB Integrated Development Environment (IDE),

included with each kit.

The MPLAB REAL ICE probe is connected to the design

engineer’s PC using a high-speed USB 2.0 interface and

is connected to the target with either a connector

compatible with the popular MPLAB ICD 2 system

(RJ11) or with the new high speed, noise tolerant, low-

voltage differential signal (LVDS) interconnection

(CAT5).

MPLAB REAL ICE is field upgradeable through future

firmware downloads in MPLAB IDE. In upcoming

releases of MPLAB IDE, new devices will be supported,

and new features will be added, such as software break-

points and assembly code trace. MPLAB REAL ICE

offers significant advantages over competitive emulators

including low-cost, full-speed emulation, real-time

variable watches, trace analysis, complex breakpoints, a

ruggedized probe interface and long (up to three meters)

interconnection cables.

20.9 MPLAB ICD 2 In-Circuit Debugger

Microchip’s In-Circuit Debugger, MPLAB ICD 2, is a

powerful, low-cost, run-time development tool,

connecting to the host PC via an RS-232 or high-speed

USB interface. This tool is based on the Flash PIC

MCUs and can be used to develop for these and other

PIC MCUs and dsPIC DSCs. The MPLAB ICD 2 utilizes

the in-circuit debugging capability built into the Flash

devices. This feature, along with Microchip’s In-Circuit

Serial ProgrammingTM (ICSPTM) protocol, offers cost-

effective, in-circuit Flash debugging from the graphical

user interface of the MPLAB Integrated Development

Environment. This enables a designer to develop and

debug source code by setting breakpoints, single step-

ping and watching variables, and CPU status and

peripheral registers. Running at full speed enables

testing hardware and applications in real time. MPLAB

ICD 2 also serves as a development programmer for

selected PIC devices.

20.10 MPLAB PM3 Device Programmer

The MPLAB PM3 Device Programmer is a universal,

CE compliant device programmer with programmable

voltage verification at VDDMIN and VDDMAX for

maximum reliability. It features a large LCD display

(128 x 64) for menus and error messages and a modu-

lar, detachable socket assembly to support various

package types. The ICSP™ cable assembly is included

as a standard item. In Stand-Alone mode, the MPLAB

PM3 Device Programmer can read, verify and program

PIC devices without a PC connection. It can also set

code protection in this mode. The MPLAB PM3

connects to the host PC via an RS-232 or USB cable.

The MPLAB PM3 has high-speed communications and

optimized algorithms for quick programming of large

memory devices and incorporates an SD/MMC card for

file storage and secure data applications.

PIC18F1230/1330

20.11 PICSTART Plus Development

Programmer

The PICSTART Plus Development Programmer is an

easy-to-use, low-cost, prototype programmer. It

connects to the PC via a COM (RS-232) port. MPLAB

Integrated Development Environment software makes

using the programmer simple and efficient. The

PICSTART Plus Development Programmer supports

most PIC devices in DIP packages up to 40 pins.

Larger pin count devices, such as the PIC16C92X and

PIC17C76X, may be supported with an adapter socket.

The PICSTART Plus Development Programmer is CE

compliant.

20.12 PICkit 2 Development Programmer

The PICkit™ 2 Development Programmer is a low-cost

programmer and selected Flash device debugger with

an easy-to-use interface for programming many of

Microchip’s baseline, mid-range and PIC18F families of

Flash memory microcontrollers. The PICkit 2 Starter Kit

includes a prototyping development board, twelve

sequential lessons, software and HI-TECH’s PICC™

Lite C compiler, and is designed to help get up to speed

quickly using PIC® microcontrollers. The kit provides

everything needed to program, evaluate and develop

applications using Microchip’s powerful, mid-range

Flash memory family of microcontrollers.

20.13 Demonstration, Development and

Evaluation Boards

A wide variety of demonstration, development and

evaluation boards for various PIC MCUs and dsPIC

DSCs allows quick application development on fully func-

tional systems. Most boards include prototyping areas for

adding custom circuitry and provide application firmware

and source code for examination and modification.

The boards support a variety of features, including LEDs,

temperature sensors, switches, speakers, RS-232

interfaces, LCD displays, potentiometers and additional

EEPROM memory.

The demonstration and development boards can be

used in teaching environments, for prototyping custom

circuits and for learning about various microcontroller

applications.

In addition to the PICDEM™ and dsPICDEM™ demon-

stration/development board series of circuits, Microchip

has a line of evaluation kits and demonstration software

for analog filter design, KEELOQ® security ICs, CAN,

IrDA®, PowerSmart® battery management, SEEVAL®

evaluation system, Sigma-Delta ADC, flow rate

sensing, plus many more.

Check the Microchip web page (www.microchip.com)

and the latest

“Product Selector Guide”

(DS00148) for

the complete list of demonstration, development and

evaluation kits.

PIC18F1230/1330

21.0 INSTRUCTION SET SUMMARY

PIC18F1230/1330 devices incorporate the standard set

of 75 PIC18 core instructions, as well as an extended set

of 8 new instructions for the optimization of code that is

recursive or that utilizes a software stack. The extended

set is discussed later in this section.

21.1 Standard Instruction Set

The standard PIC18 instruction set adds many

enhancements to the previous PIC® MCU instruction

sets, while maintaining an easy migration from these

PIC MCU instruction sets. Most instructions are a

single program memory word (16 bits), but there are

four instructions that require two program memory

locations.

Each single-word instruction is a 16-bit word divided

into an opcode, which specifies the instruction type and

one or more operands, which further specify the

operation of the instruction.

The instruction set is highly orthogonal and is grouped

into four basic categories:

•Byte-oriented operations

•Bit-oriented operations

•Literal operations

•Control operations

The PIC18 instruction set summary in Table 21-2 lists

byte-oriented, bit-oriented, literal and control

operations. Table 21-1 shows the opcode field

descriptions.

Most byte-oriented instructions have three operands:

1. The file register (specified by ‘f’)

2. The destination of the result (specified by ‘d’)

3. The accessed memory (specified by ‘a’)

The file register designator ‘f’ specifies which file

designator ‘d’ specifies where the result of the

operation is to be placed. If ‘d’ is zero, the result is

placed in the WREG register. If ‘d’ is one, the result is

placed in the file register specified in the instruction.

All bit-oriented instructions have three operands:

1. The file register (specified by ‘f’)

2. The bit in the file register (specified by ‘b’)

3. The accessed memory (specified by ‘a’)

The bit field designator ‘b’ selects the number of the bit

affected by the operation, while the file register

designator ‘f’ represents the number of the file in which

the bit is located.

The literal instructions may use some of the following

operands:

• A literal value to be loaded into a file register

(specified by ‘k’)

• The desired FSR register to load the literal value

into (specified by ‘f’)

• No operand required

(specified by ‘—’)

The control instructions may use some of the following

operands:

• A program memory address (specified by ‘n’)

• The mode of the CALL or RETURN instructions

(specified by ‘s’)

• The mode of the table read and table write

instructions (specified by ‘m’)

• No operand required

(specified by ‘—’)

All instructions are a single word, except for four

double-word instructions. These instructions were

made double-word to contain the required information

in 32 bits. In the second word, the 4 MSbs are ‘1’s. If

this second word is executed as an instruction (by

itself), it will execute as a NOP.

All single-word instructions are executed in a single

instruction cycle, unless a conditional test is true or the

program counter is changed as a result of the

instruction. In these cases, the execution takes two

instruction cycles, with the additional instruction

cycle(s) executed as a NOP.

The double-word instructions execute in two instruction

cycles.

One instruction cycle consists of four oscillator periods.

Thus, for an oscillator frequency of 4 MHz, the normal

instruction execution time is 1 μs. If a conditional test is

true, or the program counter is changed as a result of

an instruction, the instruction execution time is 2 μs.

Two-word branch instructions (if true) would take 3 μs.

Figure 21-1 shows the general formats that the

instructions can have. All examples use the convention

‘nnh’ to represent a hexadecimal number.

The Instruction Set Summary, shown in Table 21-2,

lists the standard instructions recognized by the

Microchip MPASM™ Assembler.

Section 21.1.1 “Standard Instruction Set” provides

a description of each instruction.

PIC18F1230/1330

TABLE 21-1: OPCODE FIELD DESCRIPTIONS

Field Description

aRAM access bit

a = 0: RAM location in Access RAM (BSR register is ignored)

a = 1: RAM bank is specified by BSR register

bbb Bit address within an 8-bit file register (0 to 7).

BSR Bank Select Register. Used to select the current RAM bank.

C, DC, Z, OV, N ALU Status bits: Carry, Digit Carry, Zero, Overflow, Negative.

dDestination select bit

d = 0: store result in WREG

d = 1: store result in file register f

dest Destination: either the WREG register or the specified register file location.

f8-bit Register file address (00h to FFh) or 2-bit FSR designator (0h to 3h).

fs12-bit Register file address (000h to FFFh). This is the source address.

fd12-bit Register file address (000h to FFFh). This is the destination address.

GIE Global Interrupt Enable bit.

kLiteral field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value).

label Label name.

mm The mode of the TBLPTR register for the table read and table write instructions.

Only used with table read and table write instructions:

*No change to register (such as TBLPTR with table reads and writes)

*+ Post-Increment register (such as TBLPTR with table reads and writes)

*- Post-Decrement register (such as TBLPTR with table reads and writes)

+* Pre-Increment register (such as TBLPTR with table reads and writes)

nThe relative address (2’s complement number) for relative branch instructions or the direct address for

Call/Branch and Return instructions.

PC Program Counter.

PCL Program Counter Low Byte.

PCH Program Counter High Byte.

PCLATH Program Counter High Byte Latch.

PCLATU Program Counter Upper Byte Latch.

PD Power-Down bit.

PRODH Product of Multiply High Byte.

PRODL Product of Multiply Low Byte.

sFast Call/Return mode select bit

s = 0: do not update into/from shadow registers

s = 1: certain registers loaded into/from shadow registers (Fast mode)

TBLPTR 21-bit Table Pointer (points to a program memory location).

TABLAT 8-bit Table Latch.

TO Time-out bit.

TOS Top-of-Stack.

uUnused or unchanged.

WDT Watchdog Timer.

WREG Working register (accumulator).

xDon’t care (‘0’ or ‘1’). The assembler will generate code with x = 0. It is the recommended form of use for

compatibility with all Microchip software tools.

zs7-bit offset value for indirect addressing of register files (source).

zd7-bit offset value for indirect addressing of register files (destination).

{ } Optional argument.

[text] Indicates an indexed address.

(text) The contents of text.

[expr]<n> Specifies bit n of the register indicated by the pointer expr.

→Assigned to.

< > Register bit field.

∈In the set of.

italics User-defined term (font is Courier New).

PIC18F1230/1330

FIGURE 21-1: GENERAL FORMAT FOR INSTRUCTIONS

Byte-oriented file register operations

15 10 9 8 7 0

d = 0 for result destination to be WREG register

OPCODE d a f (FILE #)

d = 1 for result destination to be file register (f)

a = 0 to force Access Bank

Bit-oriented file register operations

15 12 11 9 8 7 0

OPCODE b (BIT #) a f (FILE #)

b = 3-bit position of bit in file register (f)

Literal operations

15 8 7 0

OPCODE k (literal)

k = 8-bit immediate value

Byte to Byte move operations (2-word)

15 12 11 0

OPCODE f (Source FILE #)

CALL, GOTO and Branch operations

15 8 7 0

OPCODE n<7:0> (literal)

n = 20-bit immediate value

a = 1 for BSR to select bank

f = 8-bit file register address

a = 0 to force Access Bank

a = 1 for BSR to select bank

f = 8-bit file register address

15 12 11 0

1111 n<19:8> (literal)

15 12 11 0

1111 f (Destination FILE #)

f = 12-bit file register address

Control operations

Example Instruction

ADDWF MYREG, W, B

MOVFF MYREG1, MYREG2

BSF MYREG, bit, B

MOVLW 7Fh

GOTO Label

15 8 7 0

OPCODE n<7:0> (literal)

15 12 11 0

1111 n<19:8> (literal)

CALL MYFUNC

15 11 10 0

OPCODE n<10:0> (literal)

S = Fast bit

BRA MYFUNC

15 8 7 0

OPCODE n<7:0> (literal) BC MYFUNC

PIC18F1230/1330

TABLE 21-2: PIC18FXXXX INSTRUCTION SET

Mnemonic,

Operands Description Cycles

16-Bit Instruction Word Status

Affected Notes

MSb LSb

BYTE-ORIENTED OPERATIONS

ADDWF

ADDWFC

ANDWF

CLRF

COMF

CPFSEQ

CPFSGT

CPFSLT

DECF

DECFSZ

DCFSNZ

INCF

INCFSZ

INFSNZ

IORWF

MOVF

MOVFF

MOVWF

MULWF

NEGF

RLCF

RLNCF

RRCF

RRNCF

SETF

SUBFWB

SUBWF

SUBWFB

SWAPF

TSTFSZ

XORWF

f, d, a

f, a

f, d, a

f, a

f, d, a

fs, fd

f, a

f, d, a

f, a

f, d, a

f, a

f, d, a

Add WREG and f

Add WREG and Carry bit to f

AND WREG with f

Clear f

Complement f

Compare f with WREG, Skip =

Compare f with WREG, Skip >

Compare f with WREG, Skip <

Decrement f

Decrement f, Skip if 0

Decrement f, Skip if Not 0

Increment f

Increment f, Skip if 0

Increment f, Skip if Not 0

Inclusive OR WREG with f

Move f

Move fs (source) to 1st word

fd (destination) 2nd word

Move WREG to f

Multiply WREG with f

Negate f

Rotate Left f through Carry

Rotate Left f (No Carry)

Rotate Right f through Carry

Rotate Right f (No Carry)

Set f

Subtract f from WREG with

Borrow

Subtract WREG from f

Subtract WREG from f with

Borrow

Swap Nibbles in f

Test f, Skip if 0

Exclusive OR WREG with f

1 (2 or 3)

0010

0001

0110

0001

0110

0000

0010

0100

0010

0011

0100

0001

0101

1100

1111

0110

0000

0110

0011

0100

0011

0100

0110

0101

0011

0110

0001

01da0

0da

01da

101a

11da

001a

010a

000a

01da

11da

10da

11da

10da

00da

ffff

111a

001a

110a

01da

00da

100a

01da

11da

10da

011a

10da

ffff

C, DC, Z, OV, N

Z, N

None

C, DC, Z, OV, N

None

C, DC, Z, OV, N

None

Z, N

None

C, DC, Z, OV, N

C, Z, N

Z, N

C, Z, N

Z, N

None

C, DC, Z, OV, N

None

Z, N

1, 2

1,2

1, 2

1, 2, 3, 4

1, 2

1, 2, 3, 4

1, 2

Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value

present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an

external device, the data will be written back with a ‘0’.

2: If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if

assigned.

3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second

cycle is executed as a NOP.

4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the

first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory

locations have a valid instruction.

PIC18F1230/1330

BIT-ORIENTED OPERATIONS

BCF

BSF

BTFSC

BTFSS

BTG

f, b, a

f, d, a

Bit Clear f

Bit Set f

Bit Test f, Skip if Clear

Bit Test f, Skip if Set

Bit Toggle f

1 (2 or 3)

1001

1000

1011

1010

0111

bbba

ffff

None

1, 2

3, 4

1, 2

CONTROL OPERATIONS

BNC

BNN

BNOV

BNZ

BOV

BRA

CALL

CLRWDT

DAW

GOTO

NOP

POP

PUSH

RCALL

RESET

RETFIE

RETLW

RETURN

SLEEP

n, s

—

Branch if Carry

Branch if Negative

Branch if Not Carry

Branch if Not Negative

Branch if Not Overflow

Branch if Not Zero

Branch if Overflow

Branch Unconditionally

Branch if Zero

Call subroutine 1st word

2nd word

Clear Watchdog Timer

Decimal Adjust WREG

Go to address 1st word

2nd word

No Operation

Pop Top of Return Stack (TOS)

Push Top of Return Stack (TOS)

Relative Call

Software Device Reset

Return from Interrupt Enable

Return with Literal in WREG

Return from Subroutine

Go into Standby mode

1 (2)

1110

1101

1110

1111

0000

1110

1111

0000

1111

0000

1101

0000

0010

0110

0011

0111

0101

0001

0100

0nnn

0000

110s

kkkk

0000

1111

kkkk

0000

xxxx

0000

1nnn

0000

1100

0000

nnnn

kkkk

0000

kkkk

0000

xxxx

0000

nnnn

1111

0001

kkkk

0001

0000

nnnn

kkkk

0100

0111

kkkk

0000

xxxx

0110

0101

nnnn

1111

000s

kkkk

001s

0011

None

TO, PD

None

All

GIE/GIEH,

PEIE/GIEL

None

TO, PD

TABLE 21-2: PIC18FXXXX INSTRUCTION SET (CONTINUED)

Mnemonic,

Operands Description Cycles

16-Bit Instruction Word Status

Affected Notes

MSb LSb

Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value

present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an

external device, the data will be written back with a ‘0’.

2: If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if

assigned.

3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second

cycle is executed as a NOP.

4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the

first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory

locations have a valid instruction.

PIC18F1230/1330

LITERAL OPERATIONS

ADDLW

ANDLW

IORLW

LFSR

MOVLB

MOVLW

MULLW

RETLW

SUBLW

XORLW

f, k

Add Literal and WREG

AND Literal with WREG

Inclusive OR Literal with WREG

Move Literal (12-bit)2nd word

to FSR(f) 1st word

Move Literal to BSR<3:0>

Move Literal to WREG

Multiply Literal with WREG

Return with Literal in WREG

Subtract WREG from Literal

Exclusive OR Literal with WREG

0000

1110

1111

0000

1111

1011

1001

1110

0000

0001

1110

1101

1100

1000

1010

kkkk

00ff

kkkk

0000

kkkk

C, DC, Z, OV, N

Z, N

None

C, DC, Z, OV, N

Z, N

DATA MEMORY ↔ PROGRAM MEMORY OPERATIONS

TBLRD*

TBLRD*+

TBLRD*-

TBLRD+*

TBLWT*

TBLWT*+

TBLWT*-

TBLWT+*

Table Read

Table Read with Post-Increment

Table Read with Post-Decrement

Table Read with Pre-Increment

Table Write

Table Write with Post-Increment

Table Write with Post-Decrement

Table Write with Pre-Increment

0000

1000

1001

1010

1011

1100

1101

1110

1111

None

TABLE 21-2: PIC18FXXXX INSTRUCTION SET (CONTINUED)

Mnemonic,

Operands Description Cycles

16-Bit Instruction Word Status

Affected Notes

MSb LSb

Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value

present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an

external device, the data will be written back with a ‘0’.

2: If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if

assigned.

3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second

cycle is executed as a NOP.

4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the

first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all program memory

locations have a valid instruction.

PIC18F1230/1330

21.1.1 STANDARD INSTRUCTION SET

ADDLW ADD Literal to W

Syntax: ADDLW k

Operands: 0 ≤ k ≤ 255

Operation: (W) + k → W

Status Affected: N, OV, C, DC, Z

Encoding: 0000 1111 kkkk kkkk

Description: The contents of W are added to the

8-bit literal ‘k’ and the result is placed in

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal ‘k’

Process

Data

Write to W

Example: ADDLW 15h

Before Instruction

W = 10h

After Instruction

W = 25h

ADDWF ADD W to f

Syntax: ADDWF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) + (f) → dest

Status Affected: N, OV, C, DC, Z

Encoding: 0010 01da ffff ffff

Description: Add W to register ‘f’. If ‘d’ is ‘0’, the

result is stored in W. If ‘d’ is ‘1’, the

result is stored back in register ‘f’

(default).

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: ADDWF REG, 0, 0

Before Instruction

W = 17h

REG = 0C2h

After Instruction

W = 0D9h

REG = 0C2h

Note: All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in

symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s).

PIC18F1230/1330

ADDWFC ADD W and Carry bit to f

Syntax: ADDWFC f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) + (f) + (C) → dest

Status Affected: N,OV, C, DC, Z

Encoding: 0010 00da ffff ffff

Description: Add W, the Carry flag and data memory

location ‘f’. If ‘d’ is ‘0’, the result is

placed in W. If ‘d’ is ‘1’, the result is

placed in data memory location ‘f’.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: ADDWFC REG, 0, 1

Before Instruction

Carry bit = 1

REG = 02h

W=4Dh

After Instruction

Carry bit = 0

REG = 02h

W = 50h

ANDLW AND Literal with W

Syntax: ANDLW k

Operands: 0 ≤ k ≤ 255

Operation: (W) .AND. k → W

Status Affected: N, Z

Encoding: 0000 1011 kkkk kkkk

Description: The contents of W are ANDed with the

8-bit literal ‘k’. The result is placed in W.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

‘k’

Process

Data

Write to W

Example: ANDLW 05Fh

Before Instruction

W=A3h

After Instruction

W = 03h

PIC18F1230/1330

ANDWF AND W with f

Syntax: ANDWF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) .AND. (f) → dest

Status Affected: N, Z

Encoding: 0001 01da ffff ffff

Description: The contents of W are ANDed with

in W. If ‘d’ is ‘1’, the result is stored back

in register ‘f’ (default).

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: ANDWF REG, 0, 0

Before Instruction

W = 17h

REG = C2h

After Instruction

W = 02h

REG = C2h

BC Branch if Carry

Syntax: BC n

Operands: -128 ≤ n ≤ 127

Operation: if Carry bit is ‘1’,

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0010 nnnn nnnn

Description: If the Carry bit is ‘1’, then the program

will branch.

The 2’s complement number ‘2n’ is

added to the PC. Since the PC will have

incremented to fetch the next

instruction, the new address will be

PC + 2 + 2n. This instruction is then a

two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

Write to

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

operation

Example: HERE BC 5

Before Instruction

PC = address (HERE)

After Instruction

If Carry = 1;

PC = address (HERE + 12)

If Carry = 0;

PC = address (HERE + 2)

PIC18F1230/1330

BCF Bit Clear f

Syntax: BCF f, b {,a}

Operands: 0 ≤ f ≤ 255

0 ≤ b ≤ 7

a ∈ [0,1]

Operation: 0 → f

Status Affected: None

Encoding: 1001 bbba ffff ffff

Description: Bit ‘b’ in register ‘f’ is cleared.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example: BCF FLAG_REG, 7, 0

Before Instruction

FLAG_REG = C7h

After Instruction

FLAG_REG = 47h

BN Branch if Negative

Syntax: BN n

Operands: -128 ≤ n ≤ 127

Operation: if Negative bit is ‘1’,

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0110 nnnn nnnn

Description: If the Negative bit is ‘1’, then the

program will branch.

The 2’s complement number ‘2n’ is

added to the PC. Since the PC will have

incremented to fetch the next

instruction, the new address will be

PC + 2 + 2n. This instruction is then a

two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

Write to

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

operation

Example: HERE BN Jump

Before Instruction

PC = address (HERE)

After Instruction

If Negative = 1;

PC = address (Jump)

If Negative = 0;

PC = address (HERE + 2)

PIC18F1230/1330

BNC Branch if Not Carry

Syntax: BNC n

Operands: -128 ≤ n ≤ 127

Operation: if Carry bit is ‘0’,

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0011 nnnn nnnn

Description: If the Carry bit is ‘0’, then the program

will branch.

The 2’s complement number ‘2n’ is

added to the PC. Since the PC will have

incremented to fetch the next

instruction, the new address will be

PC + 2 + 2n. This instruction is then a

two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

Write to

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

operation

Example: HERE BNC Jump

Before Instruction

PC = address (HERE)

After Instruction

If Carry = 0;

PC = address (Jump)

If Carry = 1;

PC = address (HERE + 2)

BNN Branch if Not Negative

Syntax: BNN n

Operands: -128 ≤ n ≤ 127

Operation: if Negative bit is ‘0’,

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0111 nnnn nnnn

Description: If the Negative bit is ‘0’, then the

program will branch.

The 2’s complement number ‘2n’ is

added to the PC. Since the PC will have

incremented to fetch the next

instruction, the new address will be

PC + 2 + 2n. This instruction is then a

two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

Write to

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

operation

Example: HERE BNN Jump

Before Instruction

PC = address (HERE)

After Instruction

If Negative = 0;

PC = address (Jump)

If Negative = 1;

PC = address (HERE + 2)

PIC18F1230/1330

BNOV Branch if Not Overflow

Syntax: BNOV n

Operands: -128 ≤ n ≤ 127

Operation: if Overflow bit is ‘0’,

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0101 nnnn nnnn

Description: If the Overflow bit is ‘0’, then the

program will branch.

The 2’s complement number ‘2n’ is

added to the PC. Since the PC will have

incremented to fetch the next

instruction, the new address will be

PC + 2 + 2n. This instruction is then a

two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

Write to

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

operation

Example: HERE BNOV Jump

Before Instruction

PC = address (HERE)

After Instruction

If Overflow = 0;

PC = address (Jump)

If Overflow = 1;

PC = address (HERE + 2)

BNZ Branch if Not Zero

Syntax: BNZ n

Operands: -128 ≤ n ≤ 127

Operation: if Zero bit is ‘0’,

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0001 nnnn nnnn

Description: If the Zero bit is ‘0’, then the program

will branch.

The 2’s complement number ‘2n’ is

added to the PC. Since the PC will have

incremented to fetch the next

instruction, the new address will be

PC + 2 + 2n. This instruction is then a

two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

Write to

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

operation

Example: HERE BNZ Jump

Before Instruction

PC = address (HERE)

After Instruction

If Zero = 0;

PC = address (Jump)

If Zero = 1;

PC = address (HERE + 2)

PIC18F1230/1330

BRA Unconditional Branch

Syntax: BRA n

Operands: -1024 ≤ n ≤ 1023

Operation: (PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1101 0nnn nnnn nnnn

Description: Add the 2’s complement number ‘2n’ to

the PC. Since the PC will have

incremented to fetch the next instruction,

the new address will be PC + 2 + 2n. This

instruction is a two-cycle instruction.

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

Write to

operation

Example: HERE BRA Jump

Before Instruction

PC = address (HERE)

After Instruction

PC = address (Jump)

BSF Bit Set f

Syntax: BSF f, b {,a}

Operands: 0 ≤ f ≤ 255

0 ≤ b ≤ 7

a ∈ [0,1]

Operation: 1 → f

Status Affected: None

Encoding: 1000 bbba ffff ffff

Description: Bit ‘b’ in register ‘f’ is set.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example: BSF FLAG_REG, 7, 1

Before Instruction

FLAG_REG = 0Ah

After Instruction

FLAG_REG = 8Ah

PIC18F1230/1330

BTFSC Bit Test File, Skip if Clear

Syntax: BTFSC f, b {,a}

Operands: 0 ≤ f ≤ 255

0 ≤ b ≤ 7

a ∈ [0,1]

Operation: skip if (f) = 0

Status Affected: None

Encoding: 1011 bbba ffff ffff

Description: If bit ‘b’ in register ‘f’ is ‘0’, then the next

instruction is skipped. If bit ‘b’ is ‘0’, then

the next instruction fetched during the

current instruction execution is discarded

and a NOP is executed instead, making

this a two-cycle instruction.

If ‘a’ is ‘0’, the Access Bank is selected. If

‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates in

Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh).

See Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example: HERE

FALSE

TRUE

BTFSC

FLAG, 1, 0

Before Instruction

PC = address (HERE)

After Instruction

If FLAG<1> = 0;

PC = address (TRUE)

If FLAG<1> = 1;

PC = address (FALSE)

BTFSS Bit Test File, Skip if Set

Syntax: BTFSS f, b {,a}

Operands: 0 ≤ f ≤ 255

0 ≤ b < 7

a ∈ [0,1]

Operation: skip if (f) = 1

Status Affected: None

Encoding: 1010 bbba ffff ffff

Description: If bit ‘b’ in register ‘f’ is ‘1’, then the next

instruction is skipped. If bit ‘b’ is ‘1’, then

the next instruction fetched during the

current instruction execution is discarded

and a NOP is executed instead, making

this a two-cycle instruction.

If ‘a’ is ‘0’, the Access Bank is selected. If

‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh).

See Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example: HERE

FALSE

TRUE

BTFSS

FLAG, 1, 0

Before Instruction

PC = address (HERE)

After Instruction

If FLAG<1> = 0;

PC = address (FALSE)

If FLAG<1> = 1;

PC = address (TRUE)

PIC18F1230/1330

BTG Bit Toggle f

Syntax: BTG f, b {,a}

Operands: 0 ≤ f ≤ 255

0 ≤ b < 7

a ∈ [0,1]

Operation: (f) → f

Status Affected: None

Encoding: 0111 bbba ffff ffff

Description: Bit ‘b’ in data memory location ‘f’ is

inverted.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example: BTG PORTC, 4, 0

Before Instruction:

PORTC = 0111 0101 [75h]

After Instruction:

PORTC = 0110 0101 [65h]

BOV Branch if Overflow

Syntax: BOV n

Operands: -128 ≤ n ≤ 127

Operation: if Overflow bit is ‘1’,

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0100 nnnn nnnn

Description: If the Overflow bit is ‘1’, then the

program will branch.

The 2’s complement number ‘2n’ is

added to the PC. Since the PC will have

incremented to fetch the next

instruction, the new address will be

PC + 2 + 2n. This instruction is then a

two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

Write to

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

operation

Example: HERE BOV Jump

Before Instruction

PC = address (HERE)

After Instruction

If Overflow = 1;

PC = address (Jump)

If Overflow = 0;

PC = address (HERE + 2)

PIC18F1230/1330

BZ Branch if Zero

Syntax: BZ n

Operands: -128 ≤ n ≤ 127

Operation: if Zero bit is ‘1’,

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1110 0000 nnnn nnnn

Description: If the Zero bit is ‘1’, then the program

will branch.

The 2’s complement number ‘2n’ is

added to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC + 2 + 2n. This instruction is then a

two-cycle instruction.

Words: 1

Cycles: 1(2)

Q Cycle Activity:

If Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

Write to

operation

If No Jump:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

Process

Data

operation

Example: HERE BZ Jump

Before Instruction

PC = address (HERE)

After Instruction

If Zero = 1;

PC = address (Jump)

If Zero = 0;

PC = address (HERE + 2)

CALL Subroutine Call

Syntax: CALL k {,s}

Operands: 0 ≤ k ≤ 1048575

s ∈ [0,1]

Operation: (PC) + 4 → TOS,

k → PC<20:1>;

if s = 1,

(W) → WS,

(STATUS) → STATUSS,

(BSR) → BSRS

Status Affected: None

Encoding:

1st word (k<7:0>)

2nd word(k<19:8>)

1110

1111

110s

k19kkk

k7kkk

kkkk

kkkk0

kkkk8

Description: Subroutine call of entire 2-Mbyte

memory range. First, return address

(PC + 4) is pushed onto the return

stack. If ‘s’ = 1, the W, STATUS and

BSR registers are also pushed into their

respective shadow registers, WS,

STATUSS and BSRS. If ‘s’ = 0, no

update occurs (default). Then, the

20-bit value ‘k’ is loaded into PC<20:1>.

CALL is a two-cycle instruction.

Words: 2

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

‘k’<7:0>,

PUSH PC to

stack

Read literal

‘k’<19:8>,

Write to PC

operation

Example: HERE CALL THERE, 1

Before Instruction

PC = address (HERE)

After Instruction

PC = address (THERE)

TOS = address (HERE + 4)

WS = W

BSRS = BSR

STATUSS = STATUS

PIC18F1230/1330

CLRF Clear f

Syntax: CLRF f {,a}

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: 000h → f,

1 → Z

Status Affected: Z

Encoding: 0110 101a ffff ffff

Description: Clears the contents of the specified

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example: CLRF FLAG_REG, 1

Before Instruction

FLAG_REG = 5Ah

After Instruction

FLAG_REG = 00h

CLRWDT Clear Watchdog Timer

Syntax: CLRWDT

Operands: None

Operation: 000h → WDT,

000h → WDT postscaler,

1 → TO,

1 → PD

Status Affected: TO, PD

Encoding: 0000 0000 0000 0100

Description: CLRWDT instruction resets the

Watchdog Timer. It also resets the

postscaler of the WDT. Status bits, TO

and PD, are set.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

Process

Data

operation

Example: CLRWDT

Before Instruction

WDT Counter = ?

After Instruction

WDT Counter = 00h

WDT Postscaler = 0

TO =1

PD =1

PIC18F1230/1330

COMF Complement f

Syntax: COMF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) → dest

Status Affected: N, Z

Encoding: 0001 11da ffff ffff

Description: The contents of register ‘f’ are

complemented. If ‘d’ is ‘0’, the result is

stored in W. If ‘d’ is ‘1’, the result is

stored back in register ‘f’ (default).

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: COMF REG, 0, 0

Before Instruction

REG = 13h

After Instruction

REG = 13h

W=ECh

CPFSEQ Compare f with W, Skip if f = W

Syntax: CPFSEQ f {,a}

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (f) – (W),

skip if (f) = (W)

(unsigned comparison)

Status Affected: None

Encoding: 0110 001a ffff ffff

Description: Compares the contents of data memory

location ‘f’ to the contents of W by

performing an unsigned subtraction.

If ‘f’ = W, then the fetched instruction is

discarded and a NOP is executed

instead, making this a two-cycle

instruction.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example: HERE CPFSEQ REG, 0

NEQUAL :

EQUAL :

Before Instruction

PC Address = HERE

W=?

REG = ?

After Instruction

If REG = W;

PC = Address (EQUAL)

If REG ≠ W;

PC = Address (NEQUAL)

PIC18F1230/1330

CPFSGT Compare f with W, Skip if f > W

Syntax: CPFSGT f {,a}

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (f) – (W),

skip if (f) > (W)

(unsigned comparison)

Status Affected: None

Encoding: 0110 010a ffff ffff

Description: Compares the contents of data memory

location ‘f’ to the contents of the W by

performing an unsigned subtraction.

If the contents of ‘f’ are greater than the

contents of WREG, then the fetched

instruction is discarded and a NOP is

executed instead, making this a

two-cycle instruction.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example: HERE CPFSGT REG, 0

NGREATER :

GREATER :

Before Instruction

PC = Address (HERE)

W= ?

After Instruction

If REG > W;

PC = Address (GREATER)

If REG ≤ W;

PC = Address (NGREATER)

CPFSLT Compare f with W, Skip if f < W

Syntax: CPFSLT f {,a}

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (f) – (W),

skip if (f) < (W)

(unsigned comparison)

Status Affected: None

Encoding: 0110 000a ffff ffff

Description: Compares the contents of data memory

location ‘f’ to the contents of W by

performing an unsigned subtraction.

If the contents of ‘f’ are less than the

contents of W, then the fetched

instruction is discarded and a NOP is

executed instead, making this a

two-cycle instruction.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example: HERE CPFSLT REG, 1

NLESS :

LESS :

Before Instruction

PC = Address (HERE)

W= ?

After Instruction

If REG < W;

PC = Address (LESS)

If REG ≥ W;

PC = Address (NLESS)

PIC18F1230/1330

DAW Decimal Adjust W Register

Syntax: DAW

Operands: None

Operation: If [W<3:0> > 9] or [DC = 1] then,

(W<3:0>) + 6 → W<3:0>;

else,

(W<3:0>) → W<3:0>

If [W<7:4> + DC > 9] or [C = 1] then,

(W<7:4>) + 6 + DC → W<7:4> ;

else,

(W<7:4>) + DC → W<7:4>

Status Affected: C

Encoding: 0000 0000 0000 0111

Description: DAW adjusts the eight-bit value in W

resulting from the earlier addition of two

variables (each in packed BCD format)

and produces a correct packed BCD

result.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example 1:

DAW

Before Instruction

W=A5h

C=0

DC = 0

After Instruction

W = 05h

C=1

DC = 0

Example 2:

Before Instruction

W=CEh

C=0

DC = 0

After Instruction

W = 34h

C=1

DC = 0

DECF Decrement f

Syntax: DECF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) – 1 → dest

Status Affected: C, DC, N, OV, Z

Encoding: 0000 01da ffff ffff

Description: Decrement register ‘f’. If ‘d’ is ‘0’, the

result is stored in W. If ‘d’ is ‘1’, the

result is stored back in register ‘f’

(default).

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: DECF CNT, 1, 0

Before Instruction

CNT = 01h

Z=0

After Instruction

CNT = 00h

Z=1

PIC18F1230/1330

DECFSZ Decrement f, Skip if 0

Syntax: DECFSZ f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) – 1 → dest,

skip if result = 0

Status Affected: None

Encoding: 0010 11da ffff ffff

Description: The contents of register ‘f’ are

decremented. If ‘d’ is ‘0’, the result is

placed in W. If ‘d’ is ‘1’, the result is

placed back in register ‘f’ (default).

If the result is ‘0’, the next instruction,

which is already fetched, is discarded

and a NOP is executed instead, making

it a two-cycle instruction.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example: HERE DECFSZ CNT, 1, 1

GOTO LOOP

CONTINUE

Before Instruction

PC = Address (HERE)

After Instruction

CNT = CNT – 1

If CNT = 0;

PC = Address (CONTINUE)

If CNT ≠0;

PC = Address (HERE + 2)

DCFSNZ Decrement f, Skip if Not 0

Syntax: DCFSNZ f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) – 1 → dest,

skip if result ≠ 0

Status Affected: None

Encoding: 0100 11da ffff ffff

Description: The contents of register ‘f’ are

decremented. If ‘d’ is ‘0’, the result is

placed in W. If ‘d’ is ‘1’, the result is

placed back in register ‘f’ (default).

If the result is not ‘0’, the next

instruction, which is already fetched, is

discarded and a NOP is executed

instead, making it a two-cycle

instruction.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example: HERE DCFSNZ TEMP, 1, 0

ZERO :

NZERO :

Before Instruction

TEMP = ?

After Instruction

TEMP = TEMP – 1

If TEMP = 0;

PC = Address (ZERO)

If TEMP ≠0;

PC = Address (NZERO)

PIC18F1230/1330

GOTO Unconditional Branch

Syntax: GOTO k

Operands: 0 ≤ k ≤ 1048575

Operation: k → PC<20:1>

Status Affected: None

Encoding:

1st word (k<7:0>)

2nd word(k<19:8>)

1110

1111

k19kkk

k7kkk

kkkk

kkkk0

kkkk8

Description: GOTO allows an unconditional branch

anywhere within entire

2-Mbyte memory range. The 20-bit

value ‘k’ is loaded into PC<20:1>.

GOTO is always a two-cycle

instruction.

Words: 2

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

‘k’<7:0>,

operation

Read literal

‘k’<19:8>,

Write to PC

operation

Example: GOTO THERE

After Instruction

PC = Address (THERE)

INCF Increment f

Syntax: INCF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) + 1 → dest

Status Affected: C, DC, N, OV, Z

Encoding: 0010 10da ffff ffff

Description: The contents of register ‘f’ are

incremented. If ‘d’ is ‘0’, the result is

placed in W. If ‘d’ is ‘1’, the result is

placed back in register ‘f’ (default).

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: INCF CNT, 1, 0

Before Instruction

CNT = FFh

Z=0

C=?

DC = ?

After Instruction

CNT = 00h

Z=1

C=1

DC = 1

PIC18F1230/1330

INCFSZ Increment f, Skip if 0

Syntax: INCFSZ f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) + 1 → dest,

skip if result = 0

Status Affected: None

Encoding: 0011 11da ffff ffff

Description: The contents of register ‘f’ are

incremented. If ‘d’ is ‘0’, the result is

placed in W. If ‘d’ is ‘1’, the result is

placed back in register ‘f’ (default).

If the result is ‘0’, the next instruction,

which is already fetched, is discarded

and a NOP is executed instead, making

it a two-cycle instruction.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example: HERE INCFSZ CNT, 1, 0

NZERO :

ZERO :

Before Instruction

PC = Address (HERE)

After Instruction

CNT = CNT + 1

If CNT = 0;

PC = Address (ZERO)

If CNT ≠0;

PC = Address (NZERO)

INFSNZ Increment f, Skip if Not 0

Syntax: INFSNZ f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) + 1 → dest,

skip if result ≠ 0

Status Affected: None

Encoding: 0100 10da ffff ffff

Description: The contents of register ‘f’ are

incremented. If ‘d’ is ‘0’, the result is

placed in W. If ‘d’ is ‘1’, the result is

placed back in register ‘f’ (default).

If the result is not ‘0’, the next

instruction, which is already fetched, is

discarded and a NOP is executed

instead, making it a two-cycle

instruction.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example: HERE INFSNZ REG, 1, 0

ZERO

NZERO

Before Instruction

PC = Address (HERE)

After Instruction

REG = REG + 1

If REG ≠0;

PC = Address (NZERO)

If REG = 0;

PC = Address (ZERO)

PIC18F1230/1330

IORLW Inclusive OR Literal with W

Syntax: IORLW k

Operands: 0 ≤ k ≤ 255

Operation: (W) .OR. k → W

Status Affected: N, Z

Encoding: 0000 1001 kkkk kkkk

Description: The contents of W are ORed with the

eight-bit literal ‘k’. The result is placed in

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal ‘k’

Process

Data

Write to W

Example: IORLW 35h

Before Instruction

W=9Ah

After Instruction

W=BFh

IORWF Inclusive OR W with f

Syntax: IORWF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) .OR. (f) → dest

Status Affected: N, Z

Encoding: 0001 00da ffff ffff

Description: Inclusive OR W with register ‘f’. If ‘d’ is

‘0’, the result is placed in W. If ‘d’ is ‘1’,

the result is placed back in register ‘f’

(default).

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: IORWF RESULT, 0, 1

Before Instruction

RESULT = 13h

W = 91h

After Instruction

RESULT = 13h

W = 93h

PIC18F1230/1330

LFSR Load FSR

Syntax: LFSR f, k

Operands: 0 ≤ f ≤ 2

0 ≤ k ≤ 4095

Operation: k → FSRf

Status Affected: None

Encoding: 1110

1111

1110

0000

00ff

k7kkk

k11kkk

kkkk

Description: The 12-bit literal ‘k’ is loaded into the

File Select Register pointed to by ‘f’.

Words: 2

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

‘k’ MSB

Process

Data

Write

literal ‘k’

MSB to

FSRfH

Decode Read literal

‘k’ LSB

Process

Data

Write literal

‘k’ to FSRfL

Example: LFSR 2, 3ABh

After Instruction

FSR2H = 03h

FSR2L = ABh

MOVF Move f

Syntax: MOVF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: f → dest

Status Affected: N, Z

Encoding: 0101 00da ffff ffff

Description: The contents of register ‘f’ are moved to

a destination dependent upon the

status of ‘d’. If ‘d’ is ‘0’, the result is

placed in W. If ‘d’ is ‘1’, the result is

placed back in register ‘f’ (default).

Location ‘f’ can be anywhere in the

256-byte bank.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write W

Example: MOVF REG, 0, 0

Before Instruction

REG = 22h

W=FFh

After Instruction

REG = 22h

W = 22h

PIC18F1230/1330

MOVFF Move f to f

Syntax: MOVFF fs,fd

Operands: 0 ≤ fs ≤ 4095

0 ≤ fd ≤ 4095

Operation: (fs) → fd

Status Affected: None

Encoding:

1st word (source)

2nd word (destin.)

1100

1111

ffff

ffffs

ffffd

Description: The contents of source register ‘fs’ are

moved to destination register ‘fd’.

Location of source ‘fs’ can be anywhere

in the 4096-byte data space (000h to

FFFh) and location of destination ‘fd’

can also be anywhere from 000h to

FFFh.

Either source or destination can be W

(a useful special situation).

MOVFF is particularly useful for

transferring a data memory location to a

peripheral register (such as the transmit

buffer or an I/O port).

The MOVFF instruction cannot use the

PCL, TOSU, TOSH or TOSL as the

destination register.

Words: 2

Cycles: 2 (3)

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

(src)

Process

Data

operation

Decode No

operation

No dummy

read

operation

Write

(dest)

Example: MOVFF REG1, REG2

Before Instruction

REG1 = 33h

REG2 = 11h

After Instruction

REG1 = 33h

REG2 = 33h

MOVLB Move Literal to Low Nibble in BSR

Syntax: MOVLW k

Operands: 0 ≤ k ≤ 255

Operation: k → BSR

Status Affected: None

Encoding: 0000 0001 kkkk kkkk

Description: The eight-bit literal ‘k’ is loaded into the

Bank Select Register (BSR). The value of

BSR<7:4> always remains ‘0’, regardless

of the value of k7:k4.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal ‘k’

Process

Data

Write literal

‘k’ to BSR

Example: MOVLB 5

Before Instruction

BSR Register = 02h

After Instruction

BSR Register = 05h

PIC18F1230/1330

MOVLW Move Literal to W

Syntax: MOVLW k

Operands: 0 ≤ k ≤ 255

Operation: k → W

Status Affected: None

Encoding: 0000 1110 kkkk kkkk

Description: The eight-bit literal ‘k’ is loaded into W.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal ‘k’

Process

Data

Write to W

Example: MOVLW 5Ah

After Instruction

W=5Ah

MOVWF Move W to f

Syntax: MOVWF f {,a}

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (W) → f

Status Affected: None

Encoding: 0110 111a ffff ffff

Description: Move data from W to register ‘f’.

Location ‘f’ can be anywhere in the

256-byte bank.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example: MOVWF REG, 0

Before Instruction

W=4Fh

REG = FFh

After Instruction

W=4Fh

REG = 4Fh

PIC18F1230/1330

MULLW Multiply Literal with W

Syntax: MULLW k

Operands: 0 ≤ k ≤ 255

Operation: (W) x k → PRODH:PRODL

Status Affected: None

Encoding: 0000 1101 kkkk kkkk

Description: An unsigned multiplication is carried

out between the contents of W and the

8-bit literal ‘k’. The 16-bit result is

placed in the PRODH:PRODL register

pair. PRODH contains the high byte.

W is unchanged.

None of the Status flags are affected.

Note that neither Overflow nor Carry is

possible in this operation. A Zero result

is possible but not detected.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal ‘k’

Process

Data

Write

registers

PRODH:

PRODL

Example: MULLW 0C4h

Before Instruction

W=E2h

PRODH = ?

PRODL = ?

After Instruction

W=E2h

PRODH = ADh

PRODL = 08h

MULWF Multiply W with f

Syntax: MULWF f {,a}

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (W) x (f) → PRODH:PRODL

Status Affected: None

Encoding: 0000 001a ffff ffff

Description: An unsigned multiplication is carried

out between the contents of W and the

result is stored in the PRODH:PRODL

high byte. Both W and ‘f’ are

unchanged.

None of the Status flags are affected.

Note that neither Overflow nor Carry is

possible in this operation. A Zero

result is possible but not detected.

If ‘a’ is ‘0’, the Access Bank is

selected. If ‘a’ is ‘1’, the BSR is used

to select the GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction

operates in Indexed Literal Offset

Addressing mode whenever

f ≤ 95 (5Fh). See Section 21.2.3

“Byte-Oriented and Bit-Oriented

Instructions in Indexed Literal Offset

Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

registers

PRODH:

PRODL

Example: MULWF REG, 1

Before Instruction

W=C4h

REG = B5h

PRODH = ?

PRODL = ?

After Instruction

W=C4h

REG = B5h

PRODH = 8Ah

PRODL = 94h

PIC18F1230/1330

NEGF Negate f

Syntax: NEGF f {,a}

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: (f) + 1 → f

Status Affected: N, OV, C, DC, Z

Encoding: 0110 110a ffff ffff

Description: Location ‘f’ is negated using two’s

complement. The result is placed in the

data memory location ‘f’.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example: NEGF REG, 1

Before Instruction

REG = 0011 1010 [3Ah]

After Instruction

REG = 1100 0110 [C6h]

NOP No Operation

Syntax: NOP

Operands: None

Operation: No operation

Status Affected: None

Encoding: 0000

1111

0000

xxxx

0000

xxxx

0000

xxxx

Description: No operation.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

Example:

None.

PIC18F1230/1330

POP Pop Top of Return Stack

Syntax: POP

Operands: None

Operation: (TOS) → bit bucket

Status Affected: None

Encoding: 0000 0000 0000 0110

Description: The TOS value is pulled off the return

stack and is discarded. The TOS value

then becomes the previous value that

was pushed onto the return stack.

This instruction is provided to enable

the user to properly manage the return

stack to incorporate a software stack.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

POP TOS

value

operation

Example: POP

GOTO NEW

Before Instruction

TOS = 0031A2h

Stack (1 level down) = 014332h

After Instruction

TOS = 014332h

PC = NEW

PUSH Push Top of Return Stack

Syntax: PUSH

Operands: None

Operation: (PC + 2) → TOS

Status Affected: None

Encoding: 0000 0000 0000 0101

Description: The PC + 2 is pushed onto the top of

the return stack. The previous TOS

value is pushed down on the stack.

This instruction allows implementing a

software stack by modifying TOS and

then pushing it onto the return stack.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode PUSH

PC + 2 onto

return stack

operation

Example: PUSH

Before Instruction

TOS = 345Ah

PC = 0124h

After Instruction

PC = 0126h

TOS = 0126h

Stack (1 level down) = 345Ah

PIC18F1230/1330

RCALL Relative Call

Syntax: RCALL n

Operands: -1024 ≤ n ≤ 1023

Operation: (PC) + 2 → TOS,

(PC) + 2 + 2n → PC

Status Affected: None

Encoding: 1101 1nnn nnnn nnnn

Description: Subroutine call with a jump up to 1K

from the current location. First, return

address (PC + 2) is pushed onto the

stack. Then, add the 2’s complement

number ‘2n’ to the PC. Since the PC will

have incremented to fetch the next

instruction, the new address will be

PC + 2 + 2n. This instruction is a

two-cycle instruction.

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read literal

‘n’

PUSH PC

to stack

Process

Data

Write to

operation

Example: HERE RCALL Jump

Before Instruction

PC = Address (HERE)

After Instruction

PC = Address (Jump)

TOS = Address (HERE + 2)

RESET Reset

Syntax: RESET

Operands: None

Operation: Reset all registers and flags that are

affected by a MCLR Reset.

Status Affected: All

Encoding: 0000 0000 1111 1111

Description: This instruction provides a way to

execute a MCLR Reset in software.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Start

Reset

operation

Example: RESET

After Instruction

Registers = Reset Value

Flags* = Reset Value

PIC18F1230/1330

RETFIE Return from Interrupt

Syntax: RETFIE {s}

Operands: s ∈ [0,1]

Operation: (TOS) → PC,

1 → GIE/GIEH or PEIE/GIEL;

if s = 1,

(WS) → W,

(STATUSS) → STATUS,

(BSRS) → BSR,

PCLATU, PCLATH are unchanged

Status Affected: GIE/GIEH, PEIE/GIEL

Encoding: 0000 0000 0001 000s

Description: Return from interrupt. Stack is popped

and Top-of-Stack (TOS) is loaded into

the PC. Interrupts are enabled by

setting either the high or low-priority

global interrupt enable bit. If ‘s’ = 1, the

contents of the shadow registers, WS,

STATUSS and BSRS, are loaded into

their corresponding registers, W,

STATUS and BSR. If ‘s’ = 0, no update

of these registers occurs (default).

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

POP PC

from stack

Set GIEH or

GIEL

operation

Example: RETFIE 1

After Interrupt

PC = TOS

W=WS

BSR = BSRS

STATUS = STATUSS

GIE/GIEH, PEIE/GIEL = 1

RETLW Return Literal to W

Syntax: RETLW k

Operands: 0 ≤ k ≤ 255

Operation: k → W,

(TOS) → PC,

PCLATU, PCLATH are unchanged

Status Affected: None

Encoding: 0000 1100 kkkk kkkk

Description: W is loaded with the eight-bit literal ‘k’.

The program counter is loaded from the

top of the stack (the return address).

The high address latch (PCLATH)

remains unchanged.

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal ‘k’

Process

Data

POP PC

from stack,

Write to W

operation

Example:

CALL TABLE ; W contains table

; offset value

; W now has

; table value

TABLE

ADDWF PCL ; W = offset

RETLW k0 ; Begin table

RETLW k1 ;

RETLW kn ; End of table

Before Instruction

W = 07h

After Instruction

W = value of kn

PIC18F1230/1330

RETURN Return from Subroutine

Syntax: RETURN {s}

Operands: s ∈ [0,1]

Operation: (TOS) → PC;

if s = 1,

(WS) → W,

(STATUSS) → STATUS,

(BSRS) → BSR,

PCLATU, PCLATH are unchanged

Status Affected: None

Encoding: 0000 0000 0001 001s

Description: Return from subroutine. The stack is

popped and the top of the stack (TOS)

is loaded into the program counter. If

‘s’= 1, the contents of the shadow

registers, WS, STATUSS and BSRS,

are loaded into their corresponding

registers, W, STATUS and BSR. If

‘s’ = 0, no update of these registers

occurs (default).

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

Process

Data

POP PC

from stack

operation

Example: RETURN

After Instruction:

PC = TOS

RLCF Rotate Left f through Carry

Syntax: RLCF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f<n>) → dest<n + 1>,

(f<7>) → C,

Status Affected: C, N, Z

Encoding: 0011 01da ffff ffff

Description: The contents of register ‘f’ are rotated

one bit to the left through the Carry

flag. If ‘d’ is ‘0’, the result is placed in

W. If ‘d’ is ‘1’, the result is stored back

in register ‘f’ (default).

If ‘a’ is ‘0’, the Access Bank is

selected. If ‘a’ is ‘1’, the BSR is used to

select the GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction

operates in Indexed Literal Offset

Addressing mode whenever

f ≤ 95 (5Fh). See Section 21.2.3

“Byte-Oriented and Bit-Oriented

Instructions in Indexed Literal Offset

Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: RLCF REG, 0, 0

Before Instruction

REG = 1110 0110

C=0

After Instruction

REG = 1110 0110

W=1100 1100

C=1

Cregister f

PIC18F1230/1330

RLNCF Rotate Left f (No Carry)

Syntax: RLNCF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f<n>) → dest<n + 1>,

(f<7>) → dest<0>

Status Affected: N, Z

Encoding: 0100 01da ffff ffff

Description: The contents of register ‘f’ are rotated

one bit to the left. If ‘d’ is ‘0’, the result

is placed in W. If ‘d’ is ‘1’, the result is

stored back in register ‘f’ (default).

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: RLNCF REG, 1, 0

Before Instruction

REG = 1010 1011

After Instruction

REG = 0101 0111

RRCF Rotate Right f through Carry

Syntax: RRCF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f<n>) → dest<n – 1>,

(f<0>) → C,

Status Affected: C, N, Z

Encoding: 0011 00da ffff ffff

Description: The contents of register ‘f’ are rotated

one bit to the right through the Carry

flag. If ‘d’ is ‘0’, the result is placed in W.

If ‘d’ is ‘1’, the result is placed back in

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: RRCF REG, 0, 0

Before Instruction

REG = 1110 0110

C=0

After Instruction

REG = 1110 0110

W=0111 0011

C=0

Cregister f

PIC18F1230/1330

RRNCF Rotate Right f (No Carry)

Syntax: RRNCF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f<n>) → dest<n – 1>,

(f<0>) → dest<7>

Status Affected: N, Z

Encoding: 0100 00da ffff ffff

Description: The contents of register ‘f’ are rotated

one bit to the right. If ‘d’ is ‘0’, the result

is placed in W. If ‘d’ is ‘1’, the result is

placed back in register ‘f’ (default).

If ‘a’ is ‘0’, the Access Bank will be

selected, overriding the BSR value. If ‘a’

is ‘1’, then the bank will be selected as

per the BSR value (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example 1: RRNCF REG, 1, 0

Before Instruction

REG = 1101 0111

After Instruction

REG = 1110 1011

Example 2: RRNCF REG, 0, 0

Before Instruction

W=?

REG = 1101 0111

After Instruction

W=1110 1011

REG = 1101 0111

SETF Set f

Syntax: SETF f {,a}

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: FFh → f

Status Affected: None

Encoding: 0110 100a ffff ffff

Description: The contents of the specified register

are set to FFh.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write

Example: SETF REG, 1

Before Instruction

REG = 5Ah

After Instruction

REG = FFh

PIC18F1230/1330

SLEEP Enter Sleep mode

Syntax: SLEEP

Operands: None

Operation: 00h → WDT,

0 → WDT postscaler,

1 → TO,

0 → PD

Status Affected: TO, PD

Encoding: 0000 0000 0000 0011

Description: The Power-Down status bit (PD) is

cleared. The Time-out status bit (TO)

is set. Watchdog Timer and its

postscaler are cleared.

The processor is put into Sleep mode

with the oscillator stopped.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

Process

Data

Go to

Sleep

Example: SLEEP

Before Instruction

TO =?

PD =?

After Instruction

TO =1†

PD =0

† If WDT causes wake-up, this bit is cleared.

SUBFWB Subtract f from W with Borrow

Syntax: SUBFWB f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) – (f) – (C) → dest

Status Affected: N, OV, C, DC, Z

Encoding: 0101 01da ffff ffff

Description: Subtract register ‘f’ and Carry flag

(borrow) from W (2’s complement

method). If ‘d’ is ‘0’, the result is stored

in W. If ‘d’ is ‘1’, the result is stored in

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example 1: SUBFWB REG, 1, 0

Before Instruction

REG = 3

W=2

C=1

After Instruction

REG = FF

W=2

C=0

Z=0

N = 1 ; result is negative

Example 2: SUBFWB REG, 0, 0

Before Instruction

REG = 2

W=5

C=1

After Instruction

REG = 2

W=3

C=1

Z=0

N = 0 ; result is positive

Example 3: SUBFWB REG, 1, 0

Before Instruction

REG = 1

W=2

C=0

After Instruction

REG = 0

W=2

C=1

Z = 1 ; result is zero

N=0

PIC18F1230/1330

SUBLW Subtract W from Literal

Syntax: SUBLW k

Operands: 0 ≤ k ≤ 255

Operation: k – (W) → W

Status Affected: N, OV, C, DC, Z

Encoding: 0000 1000 kkkk kkkk

Description W is subtracted from the eight-bit

literal ‘k’. The result is placed in W.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal ‘k’

Process

Data

Write to W

Example 1: SUBLW 02h

Before Instruction

W = 01h

C=?

After Instruction

W = 01h

C = 1 ; result is positive

Z=0

N=0

Example 2: SUBLW 02h

Before Instruction

W = 02h

C=?

After Instruction

W = 00h

C = 1 ; result is zero

Z=1

N=0

Example 3: SUBLW 02h

Before Instruction

W = 03h

C=?

After Instruction

W = FFh ; (2’s complement)

C = 0 ; result is negative

Z=0

N=1

SUBWF Subtract W from f

Syntax: SUBWF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) – (W) → dest

Status Affected: N, OV, C, DC, Z

Encoding: 0101 11da ffff ffff

Description: Subtract W from register ‘f’ (2’s

complement method). If ‘d’ is ‘0’, the

result is stored in W. If ‘d’ is ‘1’, the

result is stored back in register ‘f’

(default).

If ‘a’ is ‘0’, the Access Bank is

selected. If ‘a’ is ‘1’, the BSR is used

to select the GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction

operates in Indexed Literal Offset

Addressing mode whenever

f ≤ 95 (5Fh). See Section 21.2.3

“Byte-Oriented and Bit-Oriented

Instructions in Indexed Literal Offset

Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example 1: SUBWF REG, 1, 0

Before Instruction

REG = 3

W=2

C=?

After Instruction

REG = 1

W=2

C = 1 ; result is positive

Z=0

N=0

Example 2: SUBWF REG, 0, 0

Before Instruction

REG = 2

W=2

C=?

After Instruction

REG = 2

W=0

C = 1 ; result is zero

Z=1

N=0

Example 3: SUBWF REG, 1, 0

Before Instruction

REG = 1

W=2

C=?

After Instruction

REG = FFh ;(2’s complement)

W=2

C = 0 ; result is negative

Z=0

N=1

PIC18F1230/1330

SUBWFB Subtract W from f with Borrow

Syntax: SUBWFB f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f) – (W) – (C) → dest

Status Affected: N, OV, C, DC, Z

Encoding: 0101 10da ffff ffff

Description: Subtract W and the Carry flag (borrow)

from register ‘f’ (2’s complement

method). If ‘d’ is ‘0’, the result is stored

in W. If ‘d’ is ‘1’, the result is stored back

in register ‘f’ (default).

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example 1: SUBWFB REG, 1, 0

Before Instruction

REG = 19h (0001 1001)

W=0Dh (0000 1101)

C=1

After Instruction

REG = 0Ch (0000 1011)

W=0Dh (0000 1101)

C=1

Z=0

N = 0 ; result is positive

Example 2: SUBWFB REG, 0, 0

Before Instruction

REG = 1Bh (0001 1011)

W=1Ah (0001 1010)

C=0

After Instruction

REG = 1Bh (0001 1011)

W = 00h

C=1

Z = 1 ; result is zero

N=0

Example 3: SUBWFB REG, 1, 0

Before Instruction

REG = 03h (0000 0011)

W=0Eh (0000 1101)

C=1

After Instruction

REG = F5h (1111 0100)

; [2’s comp]

W=0Eh (0000 1101)

C=0

Z=0

N = 1 ; result is negative

SWAPF Swap f

Syntax: SWAPF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (f<3:0>) → dest<7:4>,

(f<7:4>) → dest<3:0>

Status Affected: None

Encoding: 0011 10da ffff ffff

Description: The upper and lower nibbles of register

‘f’ are exchanged. If ‘d’ is ‘0’, the result

is placed in W. If ‘d’ is ‘1’, the result is

placed in register ‘f’ (default).

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: SWAPF REG, 1, 0

Before Instruction

REG = 53h

After Instruction

REG = 35h

PIC18F1230/1330

TBLRD Table Read

Syntax: TBLRD ( *; *+; *-; +*)

Operands: None

Operation: if TBLRD *,

(Prog Mem (TBLPTR)) → TABLAT,

TBLPTR – No Change;

if TBLRD *+,

(Prog Mem (TBLPTR)) → TABLAT,

(TBLPTR) + 1 → TBLPTR;

if TBLRD *-,

(Prog Mem (TBLPTR)) → TABLAT,

(TBLPTR) – 1 → TBLPTR;

if TBLRD +*,

(TBLPTR) + 1 → TBLPTR,

(Prog Mem (TBLPTR)) → TABLAT

Status Affected: None

Encoding: 0000 0000 0000 10nn

nn=0 *

=1 *+

=2 *-

=3 +*

Description: This instruction is used to read the contents

of Program Memory (P.M.). To address the

program memory, a pointer called Table

Pointer (TBLPTR) is used.

The TBLPTR (a 21-bit pointer) points to

each byte in the program memory. TBLPTR

has a 2-Mbyte address range.

TBLPTR[0] = 0: Least Significant Byte of

Program Memory Word

TBLPTR[0] = 1: Most Significant Byte of

Program Memory Word

The TBLRD instruction can modify the value

of TBLPTR as follows:

• no change

• post-increment

• post-decrement

• pre-increment

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

No operation

(Read Program

Memory)

operation

No operation

(Write

TABLAT)

TBLRD Table Read (Continued)

Example 1: TBLRD *+ ;

Before Instruction

TABLAT = 55h

TBLPTR = 00A356h

MEMORY (00A356h) = 34h

After Instruction

TABLAT = 34h

TBLPTR = 00A357h

Example 2: TBLRD +* ;

Before Instruction

TABLAT = AAh

TBLPTR = 01A357h

MEMORY (01A357h) = 12h

MEMORY (01A358h) = 34h

After Instruction

TABLAT = 34h

TBLPTR = 01A358h

PIC18F1230/1330

TBLWT Table Write

Syntax: TBLWT ( *; *+; *-; +*)

Operands: None

Operation: if TBLWT*,

(TABLAT) → Holding Register,

TBLPTR – No Change;

if TBLWT*+,

(TABLAT) → Holding Register,

(TBLPTR) + 1 → TBLPTR;

if TBLWT*-,

(TABLAT) → Holding Register,

(TBLPTR) – 1 → TBLPTR;

if TBLWT+*,

(TBLPTR) + 1 → TBLPTR,

(TABLAT) → Holding Register

Status Affected: None

Encoding: 0000 0000 0000 11nn

nn=0 *

=1 *+

=2 *-

=3 +*

Description: This instruction uses the 3 LSBs of

TBLPTR to determine which of the

8 holding registers the TABLAT is written

to. The holding registers are used to

program the contents of Program

Memory (P.M.). (Refer to Section 6.0

“Flash Program Memory” for additional

details on programming Flash memory.)

The TBLPTR (a 21-bit pointer) points to

each byte in the program memory.

TBLPTR has a 2-Mbyte address range.

The LSb of the TBLPTR selects which

byte of the program memory location to

access.

TBLPTR[0] = 0: Least Significant Byte

of Program Memory

Word

TBLPTR[0] = 1: Most Significant Byte

of Program Memory

Word

The TBLWT instruction can modify the

value of TBLPTR as follows:

• no change

• post-increment

• post-decrement

• pre-increment

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode No

operation

(Read

TABLAT)

operation

(Write to

Holding

TBLWT Table Write (Continued)

Example 1: TBLWT *+;

Before Instruction

TABLAT = 55h

TBLPTR = 00A356h

HOLDING REGISTER

(00A356h) = FFh

After Instructions (table write completion)

TABLAT = 55h

TBLPTR = 00A357h

HOLDING REGISTER

(00A356h) = 55h

Example 2: TBLWT +*;

Before Instruction

TABLAT = 34h

TBLPTR = 01389Ah

HOLDING REGISTER

(01389Ah) = FFh

HOLDING REGISTER

(01389Bh) = FFh

After Instruction (table write completion)

TABLAT = 34h

TBLPTR = 01389Bh

HOLDING REGISTER

(01389Ah) = FFh

HOLDING REGISTER

(01389Bh) = 34h

PIC18F1230/1330

TSTFSZ Test f, Skip if 0

Syntax: TSTFSZ f {,a}

Operands: 0 ≤ f ≤ 255

a ∈ [0,1]

Operation: skip if f = 0

Status Affected: None

Encoding: 0110 011a ffff ffff

Description: If ‘f’ = 0, the next instruction fetched

during the current instruction execution

is discarded and a NOP is executed,

making this a two-cycle instruction.

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1(2)

Note: 3 cycles if skip and followed

by a 2-word instruction.

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

operation

If skip:

Q1 Q2 Q3 Q4

operation

If skip and followed by 2-word instruction:

Q1 Q2 Q3 Q4

operation

Example: HERE TSTFSZ CNT, 1

NZERO :

ZERO :

Before Instruction

PC = Address (HERE)

After Instruction

If CNT = 00h,

PC = Address (ZERO)

If CNT ≠00h,

PC = Address (NZERO)

XORLW Exclusive OR Literal with W

Syntax: XORLW k

Operands: 0 ≤ k ≤ 255

Operation: (W) .XOR. k → W

Status Affected: N, Z

Encoding: 0000 1010 kkkk kkkk

Description: The contents of W are XORed with

the 8-bit literal ‘k’. The result is placed

in W.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal ‘k’

Process

Data

Write to W

Example: XORLW 0AFh

Before Instruction

W=B5h

After Instruction

W=1Ah

PIC18F1230/1330

XORWF Exclusive OR W with f

Syntax: XORWF f {,d {,a}}

Operands: 0 ≤ f ≤ 255

d ∈ [0,1]

a ∈ [0,1]

Operation: (W) .XOR. (f) → dest

Status Affected: N, Z

Encoding: 0001 10da ffff ffff

Description: Exclusive OR the contents of W with

in W. If ‘d’ is ‘1’, the result is stored back

in the register ‘f’ (default).

If ‘a’ is ‘0’, the Access Bank is selected.

If ‘a’ is ‘1’, the BSR is used to select the

GPR bank (default).

If ‘a’ is ‘0’ and the extended instruction

set is enabled, this instruction operates

in Indexed Literal Offset Addressing

mode whenever f ≤ 95 (5Fh). See

Section 21.2.3 “Byte-Oriented and

Bit-Oriented Instructions in Indexed

Literal Offset Mode” for details.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: XORWF REG, 1, 0

Before Instruction

REG = AFh

W=B5h

After Instruction

REG = 1Ah

W=B5h

PIC18F1230/1330

21.2 Extended Instruction Set

In addition to the standard 75 instructions of the PIC18

instruction set, PIC18F1230/1330 devices also provide

an optional extension to the core CPU functionality.

The added features include eight additional instruc-

tions that augment indirect and indexed addressing

operations and the implementation of Indexed Literal

Offset Addressing mode for many of the standard

PIC18 instructions.

The additional features of the extended instruction set

are disabled by default. To enable them, users must set

the XINST Configuration bit.

The instructions in the extended set (with the exception

of CALLW, MOVSF and MOVSS) can all be classified as

literal operations, which either manipulate the File

Select Registers, or use them for indexed addressing.

Two of the instructions, ADDFSR and SUBFSR, each

have an additional special instantiation for using FSR2.

These versions (ADDULNK and SUBULNK) allow for

automatic return after execution.

The extended instructions are specifically implemented

to optimize re-entrant program code (that is, code that

is recursive or that uses a software stack) written in

high-level languages, particularly C. Among other

things, they allow users working in high-level

languages to perform certain operations on data

structures more efficiently. These include:

• Dynamic allocation and deallocation of software

stack space when entering and leaving

subroutines

• Function Pointer invocation

• Software Stack Pointer manipulation

• Manipulation of variables located in a software

stack

A summary of the instructions in the extended instruction

set is provided in Table 21-3. Detailed descriptions are

provided in Section 21.2.2 “Extended Instruction

Set”. The opcode field descriptions in Table 21-1

(page 208) apply to both the standard and extended

PIC18 instruction sets.

21.2.1 EXTENDED INSTRUCTION SYNTAX

Most of the extended instructions use indexed

arguments, using one of the File Select Registers and

some offset to specify a source or destination register.

When an argument for an instruction serves as part of

indexed addressing, it is enclosed in square brackets

(“[ ]”). This is done to indicate that the argument is used

as an index or offset. The MPASM™ Assembler will

flag an error if it determines that an index or offset value

is not bracketed.

When the extended instruction set is enabled, brackets

are also used to indicate index arguments in byte-

oriented and bit-oriented instructions. This is in addition

to other changes in their syntax. For more details, see

Section 21.2.3.1 “Extended Instruction Syntax with

Standard PIC18 Commands”.

TABLE 21-3: EXTENSIONS TO THE PIC18 INSTRUCTION SET

Note: The instruction set extension and the

Indexed Literal Offset Addressing mode

were designed for optimizing applications

written in C; the user may likely never use

these instructions directly in the assem-

bler. The syntax for these commands is

provided as a reference for users who may

be reviewing code that has been

generated by a compiler.

Note: In the past, square brackets have been

used to denote optional arguments in the

PIC18 and earlier instruction sets. In this

text and going forward, optional

arguments are denoted by braces (“{ }”).

Mnemonic,

Operands Description Cycles

16-Bit Instruction Word Status

Affected

MSb LSb

ADDFSR

ADDULNK

CALLW

MOVSF

MOVSS

PUSHL

SUBFSR

SUBULNK

f, k

zs, fd

zs, zd

f, k

Add Literal to FSR

Add Literal to FSR2 and Return

Call Subroutine using WREG

Move zs (source) to 1st word

fd (destination) 2nd word

Move zs (source) to 1st word

zd (destination) 2nd word

Store Literal at FSR2,

Decrement FSR2

Subtract Literal from FSR

Subtract Literal from FSR2 and

Return

1110

0000

1110

1111

1110

1111

1110

1000

0000

1011

ffff

1011

xxxx

1010

1001

ffkk

11kk

0001

0zzz

ffff

1zzz

xzzz

kkkk

ffkk

11kk

kkkk

0100

zzzz

ffff

zzzz

kkkk

None

PIC18F1230/1330

21.2.2 EXTENDED INSTRUCTION SET

ADDFSR Add Literal to FSR

Syntax: ADDFSR f, k

Operands: 0 ≤ k ≤ 63

f ∈ [ 0, 1, 2 ]

Operation: FSR(f) + k → FSR(f)

Status Affected: None

Encoding: 1110 1000 ffkk kkkk

Description: The 6-bit literal ‘k’ is added to the

contents of the FSR specified by ‘f’.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal ‘k’

Process

Data

Write to

FSR

Example: ADDFSR 2, 23h

Before Instruction

FSR2 = 03FFh

After Instruction

FSR2 = 0422h

ADDULNK Add Literal to FSR2 and Return

Syntax: ADDULNK k

Operands: 0 ≤ k ≤ 63

Operation: FSR2 + k → FSR2,

(TOS) → PC

Status Affected: None

Encoding: 1110 1000 11kk kkkk

Description: The 6-bit literal ‘k’ is added to the

contents of FSR2. A RETURN is then

executed by loading the PC with the

TOS.

The instruction takes two cycles to

execute; a NOP is performed during the

second cycle.

This may be thought of as a special

case of the ADDFSR instruction, where

f = 3 (binary ‘11’); it operates only on

FSR2.

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

literal ‘k’

Process

Data

Write to

FSR

Operation

Example: ADDULNK 23h

Before Instruction

FSR2 = 03FFh

PC = 0100h

After Instruction

FSR2 = 0422h

PC = (TOS)

Note: All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in

symbolic addressing. If a label is used, the instruction syntax then becomes: {label} instruction argument(s).

PIC18F1230/1330

CALLW Subroutine Call Using WREG

Syntax: CALLW

Operands: None

Operation: (PC + 2) → TOS,

(W) → PCL,

(PCLATH) → PCH,

(PCLATU) → PCU

Status Affected: None

Encoding: 0000 0000 0001 0100

Description First, the return address (PC + 2) is

pushed onto the return stack. Next, the

contents of W are written to PCL; the

existing value is discarded. Then, the

contents of PCLATH and PCLATU are

latched into PCH and PCU,

respectively. The second cycle is

executed as a NOP instruction while the

new next instruction is fetched.

Unlike CALL, there is no option to

update W, STATUS or BSR.

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

WREG

PUSH PC to

stack

operation

Example: HERE CALLW

Before Instruction

PC = address (HERE)

PCLATH = 10h

PCLATU = 00h

W = 06h

After Instruction

PC = 001006h

TOS = address (HERE + 2)

PCLATH = 10h

PCLATU = 00h

W = 06h

MOVSF Move Indexed to f

Syntax: MOVSF [zs], fd

Operands: 0 ≤ zs ≤ 127

0 ≤ fd ≤ 4095

Operation: ((FSR2) + zs) → fd

Status Affected: None

Encoding:

1st word (source)

2nd word (destin.)

1110

1111

1011

ffff

0zzz

ffff

zzzzs

ffffd

Description: The contents of the source register are

moved to destination register ‘fd’. The

actual address of the source register is

determined by adding the 7-bit literal

offset ‘zs’ in the first word to the value of

FSR2. The address of the destination

‘fd’ in the second word. Both addresses

can be anywhere in the 4096-byte data

space (000h to FFFh).

The MOVSF instruction cannot use the

PCL, TOSU, TOSH or TOSL as the

destination register.

If the resultant source address points to

an indirect addressing register, the

value returned will be 00h.

Words: 2

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Determine

source addr

Determine

source addr

Read

source reg

Decode No

operation

No dummy

read

operation

Write

(dest)

Example: MOVSF [05h], REG2

Before Instruction

FSR2 = 80h

Contents

of 85h = 33h

REG2 = 11h

After Instruction

FSR2 = 80h

Contents

of 85h = 33h

REG2 = 33h

PIC18F1230/1330

MOVSS Move Indexed to Indexed

Syntax: MOVSS [zs], [zd]

Operands: 0 ≤ zs ≤ 127

0 ≤ zd ≤ 127

Operation: ((FSR2) + zs) → ((FSR2) + zd)

Status Affected: None

Encoding:

1st word (source)

2nd word (dest.)

1110

1111

1011

xxxx

1zzz

xzzz

zzzzs

zzzzd

Description The contents of the source register are

moved to the destination register. The

addresses of the source and destination

registers are determined by adding the

7-bit literal offsets ‘zs’ or ‘zd’,

respectively, to the value of FSR2. Both

registers can be located anywhere in

the 4096-byte data memory space

(000h to FFFh).

The MOVSS instruction cannot use the

PCL, TOSU, TOSH or TOSL as the

destination register.

If the resultant source address points to

an indirect addressing register, the

value returned will be 00h. If the

resultant destination address points to

an indirect addressing register, the

instruction will execute as a NOP.

Words: 2

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Determine

source addr

Determine

source addr

Read

source reg

Decode Determine

dest addr

Determine

dest addr

Write

to dest reg

Example: MOVSS [05h], [06h]

Before Instruction

FSR2 = 80h

Contents

of 85h = 33h

Contents

of 86h = 11h

After Instruction

FSR2 = 80h

Contents

of 85h = 33h

Contents

of 86h = 33h

PUSHL

Store Literal at FSR2, Decrement FSR2

Syntax: PUSHL k

Operands: 0 ≤ k ≤ 255

Operation: k → (FSR2),

FSR2 – 1 → FSR2

Status Affected: None

Encoding: 1111 1010 kkkk kkkk

Description: The 8-bit literal ‘k’ is written to the data

memory address specified by FSR2. FSR2

is decremented by 1 after the operation.

This instruction allows users to push values

onto a software stack.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read ‘k’ Process

data

Write to

destination

Example: PUSHL 08h

Before Instruction

FSR2H:FSR2L = 01ECh

Memory (01ECh) = 00h

After Instruction

FSR2H:FSR2L = 01EBh

Memory (01ECh) = 08h

PIC18F1230/1330

SUBFSR Subtract Literal from FSR

Syntax: SUBFSR f, k

Operands: 0 ≤ k ≤ 63

f ∈ [ 0, 1, 2 ]

Operation: FSR(f – k) → FSR(f)

Status Affected: None

Encoding: 1110 1001 ffkk kkkk

Description: The 6-bit literal ‘k’ is subtracted from

the contents of the FSR specified

by ‘f’.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: SUBFSR 2, 23h

Before Instruction

FSR2 = 03FFh

After Instruction

FSR2 = 03DCh

SUBULNK

Subtract Literal from FSR2 and Return

Syntax: SUBULNK k

Operands: 0 ≤ k ≤ 63

Operation: FSR2 – k → FSR2,

(TOS) → PC

Status

Affected:

None

Encoding: 1110 1001 11kk kkkk

Description: The 6-bit literal ‘k’ is subtracted from the

contents of the FSR2. A RETURN is then

executed by loading the PC with the TOS.

The instruction takes two cycles to

execute; a NOP is performed during the

second cycle.

This may be thought of as a special case of

the SUBFSR instruction, where f = 3 (binary

‘11’); it operates only on FSR2.

Words: 1

Cycles: 2

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Operation

Example: SUBULNK 23h

Before Instruction

FSR2 = 03FFh

PC = 0100h

After Instruction

FSR2 = 03DCh

PC = (TOS)

PIC18F1230/1330

21.2.3 BYTE-ORIENTED AND

BIT-ORIENTED INSTRUCTIONS IN

INDEXED LITERAL OFFSET MODE

In addition to eight new commands in the extended set,

enabling the extended instruction set also enables

Indexed Literal Offset Addressing mode (Section 5.5.1

“Indexed Addressing with Literal Offset”). This has

a significant impact on the way that many commands of

the standard PIC18 instruction set are interpreted.

When the extended set is disabled, addresses embed-

ded in opcodes are treated as literal memory locations:

either as a location in the Access Bank (‘a’ = 0) or in a

GPR bank designated by the BSR (‘a’ = 1). When the

extended instruction set is enabled and ‘a’ = 0,

however, a file register argument of 5Fh or less is

interpreted as an offset from the pointer value in FSR2

and not as a literal address. For practical purposes, this

means that all instructions that use the Access RAM bit

as an argument – that is, all byte-oriented and bit-

oriented instructions, or almost half of the core PIC18

instructions – may behave differently when the

extended instruction set is enabled.

When the content of FSR2 is 00h, the boundaries of the

Access RAM are essentially remapped to their original

values. This may be useful in creating backward

compatible code. If this technique is used, it may be

necessary to save the value of FSR2 and restore it

when moving back and forth between C and assembly

routines in order to preserve the Stack Pointer. Users

must also keep in mind the syntax requirements of the

extended instruction set (see Section 21.2.3.1

“Extended Instruction Syntax with Standard PIC18

Commands”).

Although the Indexed Literal Offset Addressing mode

can be very useful for dynamic stack and pointer

manipulation, it can also be very annoying if a simple

arithmetic operation is carried out on the wrong

programming must keep in mind that, when the

extended instruction set is enabled, register addresses

of 5Fh or less are used for Indexed Literal Offset

Addressing mode.

Representative examples of typical byte-oriented and

bit-oriented instructions in the Indexed Literal Offset

Addressing mode are provided on the following page to

show how execution is affected. The operand

conditions shown in the examples are applicable to all

instructions of these types.

21.2.3.1 Extended Instruction Syntax with

Standard PIC18 Commands

When the extended instruction set is enabled, the file

bit-oriented commands is replaced with the literal offset

value, ‘k’. As already noted, this occurs only when ‘f’ is

less than or equal to 5Fh. When an offset value is used,

it must be indicated by square brackets (“[ ]”). As with

the extended instructions, the use of brackets indicates

to the compiler that the value is to be interpreted as an

index or an offset. Omitting the brackets, or using a

value greater than 5Fh within brackets, will generate an

error in the MPASM Assembler.

If the index argument is properly bracketed for Indexed

Literal Offset Addressing mode, the Access RAM

argument is never specified; it will automatically be

assumed to be ‘0’. This is in contrast to standard

operation (extended instruction set disabled) when ‘a’

is set on the basis of the target address. Declaring the

Access RAM bit in this mode will also generate an error

in the MPASM Assembler.

The destination argument, ‘d’, functions as before.

In the latest versions of the MPASM Assembler,

language support for the extended instruction set must

be explicitly invoked. This is done with either the

command line option, /y, or the PE directive in the

source listing.

21.2.4 CONSIDERATIONS WHEN

ENABLING THE EXTENDED

INSTRUCTION SET

It is important to note that the extensions to the instruc-

tion set may not be beneficial to all users. In particular,

users who are not writing code that uses a software

stack may not benefit from using the extensions to the

instruction set.

Additionally, the Indexed Literal Offset Addressing

mode may create issues with legacy applications

written to the PIC18 assembler. This is because

instructions in the legacy code may attempt to address

registers in the Access Bank below 5Fh. Since these

addresses are interpreted as literal offsets to FSR2

when the instruction set extension is enabled, the

application may read or write to the wrong data

addresses.

When porting an application to the PIC18F1230/1330,

it is very important to consider the type of code. A large,

re-entrant application that is written in ‘C’ and would

benefit from efficient compilation will do well when

using the instruction set extensions. Legacy

applications that heavily use the Access Bank will most

likely not benefit from using the extended instruction

set.

Note: Enabling the PIC18 instruction set

extension may cause legacy applications

to behave erratically or fail entirely.

PIC18F1230/1330

ADDWF ADD W to Indexed

(Indexed Literal Offset mode)

Syntax: ADDWF [k] {,d}

Operands: 0 ≤ k ≤ 95

d ∈ [0,1]

Operation: (W) + ((FSR2) + k) → dest

Status Affected: N, OV, C, DC, Z

Encoding: 0010 01d0 kkkk kkkk

Description: The contents of W are added to the

contents of the register indicated by

FSR2, offset by the value ‘k’.

If ‘d’ is ‘0’, the result is stored in W. If ‘d’

is ‘1’, the result is stored back in

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read ‘k’ Process

Data

Write to

destination

Example: ADDWF [OFST] , 0

Before Instruction

W = 17h

OFST = 2Ch

FSR2 = 0A00h

Contents

of 0A2Ch = 20h

After Instruction

W = 37h

Contents

of 0A2Ch = 20h

BSF Bit Set Indexed

(Indexed Literal Offset mode)

Syntax: BSF [k], b

Operands: 0 ≤ f ≤ 95

0 ≤ b ≤ 7

Operation: 1 → ((FSR2) + k)

Status Affected: None

Encoding: 1000 bbb0 kkkk kkkk

Description: Bit ‘b’ of the register indicated by FSR2,

offset by the value ‘k’, is set.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read

Process

Data

Write to

destination

Example: BSF [FLAG_OFST], 7

Before Instruction

FLAG_OFST = 0Ah

FSR2 = 0A00h

Contents

of 0A0Ah = 55h

After Instruction

Contents

of 0A0Ah = D5h

SETF Set Indexed

(Indexed Literal Offset mode)

Syntax: SETF [k]

Operands: 0 ≤ k ≤ 95

Operation: FFh → ((FSR2) + k)

Status Affected: None

Encoding: 0110 1000 kkkk kkkk

Description: The contents of the register indicated

by FSR2, offset by ‘k’, are set to FFh.

Words: 1

Cycles: 1

Q Cycle Activity:

Q1 Q2 Q3 Q4

Decode Read ‘k’ Process

Data

Write

Example: SETF [OFST]

Before Instruction

OFST = 2Ch

FSR2 = 0A00h

Contents

of 0A2Ch = 00h

After Instruction

Contents

of 0A2Ch = FFh

PIC18F1230/1330

21.2.5 SPECIAL CONSIDERATIONS WITH

MICROCHIP MPLAB® IDE TOOLS

The latest versions of Microchip’s software tools have

been designed to fully support the extended instruction

set of the PIC18F1230/1330 family of devices. This

includes the MPLAB C18 C Compiler, MPASM Assem-

bly language and MPLAB Integrated Development

Environment (IDE).

When selecting a target device for software

development, MPLAB IDE will automatically set default

Configuration bits for that device. The default setting for

the XINST Configuration bit is ‘0’, disabling the

extended instruction set and Indexed Literal Offset

Addressing mode. For proper execution of applications

developed to take advantage of the extended

instruction set, XINST must be set during

programming.

To develop software for the extended instruction set,

the user must enable support for the instructions and

the Indexed Addressing mode in their language tool(s).

Depending on the environment being used, this may be

done in several ways:

• A menu option, or dialog box within the

environment, that allows the user to configure the

language tool and its settings for the project

• A command line option

• A directive in the source code

These options vary between different compilers,

assemblers and development environments. Users are

encouraged to review the documentation accompany-

ing their development systems for the appropriate

information.

PIC18F1230/1330

22.0 ELECTRICAL CHARACTERISTICS

Absolute Maximum Ratings(†)

Ambient temperature under bias.............................................................................................................-40°C to +125°C

Storage temperature .............................................................................................................................. -65°C to +150°C

Voltage on any pin with respect to VSS (except VDD and MCLR) ................................................... -0.3V to (VDD + 0.3V)

Voltage on VDD with respect to VSS ......................................................................................................... -0.3V to +7.5V

Voltage on MCLR with respect to VSS (Note 2) ......................................................................................... 0V to +13.25V

Total power dissipation (Note 1) ...............................................................................................................................1.0W

Maximum current out of VSS pin ...........................................................................................................................300 mA

Maximum current into VDD pin ..............................................................................................................................250 mA

Input clamp current, IIK (VI < 0 or VI > VDD)...................................................................................................................... ±20 mA

Output clamp current, IOK (VO < 0 or VO > 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

Maximum current sunk by all ports .......................................................................................................................200 mA

Maximum current sourced by all ports ..................................................................................................................200 mA

Note 1: Power dissipation is calculated as follows:

Pdis = VDD x {IDD – ∑ IOH} + ∑ {(VDD – VOH) x IOH} + ∑(VOL x IOL)

2: Voltage spikes below VSS at the MCLR/VPP/RA5/FLTA pin, inducing currents greater than 80 mA, may

cause latch-up. Thus, a series resistor of 50-100Ω should be used when applying a “low” level to the MCLR/

VPP/RA5/FLTA pin, rather than pulling this pin directly to VSS.

† NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the

device. This is a stress rating only and functional operation of the device at those or any other conditions above those

indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for

extended periods may affect device reliability.

PIC18F1230/1330

FIGURE 22-1: PIC18F1230/1330 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)

FIGURE 22-2: PIC18F1230/1330 VOLTAGE-FREQUENCY GRAPH (EXTENDED)

Frequency

Voltage

6.0V

5.5V

4.5V

4.0V

2.0V

40 MHz

5.0V

3.5V

3.0V

2.5V

PIC18F1230/1330

4.2V

Frequency

Voltage

6.0V

5.5V

4.5V

4.0V

2.0V

25 MHz

5.0V

3.5V

3.0V

2.5V

PIC18F1230/1330

4.2V

PIC18F1230/1330

FIGURE 22-3: PIC18LF1230/1330 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)

Frequency

Voltage

6.0V

5.5V

4.5V

4.0V

2.0V

40 MHz

5.0V

3.5V

3.0V

2.5V

PIC18LF1230/1330

FMAX = (16.36 MHz/V) (VDDAPPMIN – 2.0V) + 4 MHz

Note: VDDAPPMIN is the minimum voltage of the PIC® device in the application.

4 MHz

4.2V

PIC18F1230/1330

22.1 DC Characteristics: Supply Voltage

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

-40°C ≤ TA ≤ +125°C for extended

Param

No. Symbol Characteristic Min Typ Max Units Conditions

D001 VDD Supply Voltage

PIC18LF1230/1330 2.0 — 5.5 V HS, XT, RC and LP Oscillator modes

PIC18F1230/1330 4.2 —5.5 V

D002 VDR RAM Data Retention

Voltage(1)

1.5 — — V

D003 VPOR VDD Start Voltage

to ensure internal

Power-on Reset signal

— — 0.7 V See section on Power-on Reset for details

D004 SVDD VDD Rise Rate

to ensure internal

Power-on Reset signal

0.05 — — V/ms See section on Power-on Reset for details

VBOR Brown-out Reset Voltage

D005 PIC18LF1230/1330

BORV1:BORV0 = 11 2.00 2.05 2.16 V

BORV1:BORV0 = 10 2.65 2.79 2.93 V

D005 All devices

BORV1:BORV0 = 01 4.11 4.33 4.55 V

BORV1:BORV0 = 00 4.36 4.59 4.82 V

Legend: Shading of rows is to assist in readability of the table.

Note 1: This is the limit to which VDD can be lowered in Sleep mode, or during a device Reset, without losing RAM data.

PIC18F1230/1330

22.2 DC Characteristics: Power-Down and Supply Current

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

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 Typ Max Units Conditions

Power-Down Current (IPD)(1)

PIC18LF1230/1330 100 742 nA -40°C

VDD = 2.0V

(Sleep mode)

0.1 0.742 μA+25°C

0.2 4.792 μA+85°C

PIC18LF1230/1330 0.1 1.192 μA-40°C

VDD = 3.0V

(Sleep mode)

0.1 1.192 μA+25°C

0.3 7.792 μA+85°C

All devices 0.1 7.79 μA-40°C

VDD = 5.0V

(Sleep mode)

0.1 7.79 μA+25°C

0.4 14.79 μA+85°C

Extended devices only 10 TBD μA +125°C

Legend: TBD = To Be Determined. Shading of rows is to assist in readability of the table.

Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured

with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that

add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.).

2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin

loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have

an impact on the current consumption.

The test conditions for all IDD measurements in active operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS;

MCLR = VDD; WDT enabled/disabled as specified.

3: Low-power Timer1 oscillator selected.

4: BOR and LVD enable internal band gap reference. With both modules enabled, current consumption will be less

than the sum of both specifications.

PIC18F1230/1330

Supply Current (IDD)(2)

PIC18LF1230/1330 15 28.1 μA -40°C

VDD = 2.0V

FOSC = 31 kHz

(RC_RUN mode,

INTRC source)

15 28.1 μA+25°C

15 28.1 μA+85°C

PIC18LF1230/1330 40 54 μA -40°C

VDD = 3.0V35 54 μA+25°C

30 54 μA+85°C

All devices 105 149 μA -40°C

VDD = 5.0V

90 149 μA+25°C

80 149 μA+85°C

Extended devices only 80 TBD μA +125°C

PIC18LF1230/1330 0.32 0.93 mA -40°C

VDD = 2.0V

FOSC = 1 MHz

(RC_RUN mode,

INTOSC source)

0.33 0.93 mA +25°C

0.33 0.93 mA +85°C

PIC18LF1230/1330 0.6 1.03 mA -40°C

VDD = 3.0V0.55 1.03 mA +25°C

0.6 1.03 mA +85°C

All devices 1.1 2.03 mA -40°C

VDD = 5.0V

1.1 2.03 mA +25°C

1.0 2.03 mA +85°C

Extended devices only 1 TBD mA +125°C

22.2 DC Characteristics: Power-Down and Supply Current

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial) (Continued)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

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 Typ Max Units Conditions

Legend: TBD = To Be Determined. Shading of rows is to assist in readability of the table.

Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured

with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that

add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.).

2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin

loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have

an impact on the current consumption.

The test conditions for all IDD measurements in active operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS;

MCLR = VDD; WDT enabled/disabled as specified.

3: Low-power Timer1 oscillator selected.

4: BOR and LVD enable internal band gap reference. With both modules enabled, current consumption will be less

than the sum of both specifications.

PIC18F1230/1330

Supply Current (IDD)(2)

PIC18LF1230/1330 0.8 1.83 mA -40°C

VDD = 2.0V

FOSC = 4 MHz

(RC_RUN mode,

INTOSC source)

0.8 1.83 mA +25°C

0.8 1.83 mA +85°C

PIC18LF1230/1330 1.3 2.93 mA -40°C

VDD = 3.0V1.3 2.93 mA +25°C

1.3 2.93 mA +85°C

All devices 2.5 4.73 mA -40°C

VDD = 5.0V

2.5 4.73 mA +25°C

2.5 4.73 mA +85°C

Extended devices only 2.5 TBD mA +125°C

PIC18LF1230/1330 2.9 7.6 μA -40°C

VDD = 2.0V

FOSC = 31 kHz

(RC_IDLE mode,

INTRC source)

3.1 7.6 μA+25°C

3.6 10.6 μA+85°C

PIC18LF1230/1330 4.5 10.6 μA -40°C

VDD = 3.0V4.8 10.6 μA+25°C

5.8 14.6 μA+85°C

All devices 9.2 15.6 μA -40°C

VDD = 5.0V

9.8 15.6 μA+25°C

11.4 35.6 μA+85°C

Extended devices only 21 TBD μA +125°C

22.2 DC Characteristics: Power-Down and Supply Current

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial) (Continued)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

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 Typ Max Units Conditions

Legend: TBD = To Be Determined. Shading of rows is to assist in readability of the table.

Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured

with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that

add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.).

2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin

loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have

an impact on the current consumption.

The test conditions for all IDD measurements in active operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS;

MCLR = VDD; WDT enabled/disabled as specified.

3: Low-power Timer1 oscillator selected.

4: BOR and LVD enable internal band gap reference. With both modules enabled, current consumption will be less

than the sum of both specifications.

PIC18F1230/1330

Supply Current (IDD)(2)

PIC18LF1230/1330 165 347 μA -40°C

VDD = 2.0V

FOSC = 1 MHz

(RC_IDLE mode,

INTOSC source)

175 347 μA+25°C

190 347 μA+85°C

PIC18LF1230/1330 250 497 μA -40°C

VDD = 3.0V270 497 μA+25°C

290 497 μA+85°C

All devices 500 930 mA -40°C

VDD = 5.0V

520 930 mA +25°C

550 930 mA +85°C

Extended devices only 0.6 TBD mA +125°C

PIC18LF1230/1330 340 497 μA -40°C

VDD = 2.0V

FOSC = 4 MHz

(RC_IDLE mode,

INTOSC source)

350 497 μA+25°C

360 497 μA+85°C

PIC18LF1230/1330 520 830 μA -40°C

VDD = 3.0V540 830 μA+25°C

580 830 μA+85°C

All devices 1.0 1.33 mA -40°C

VDD = 5.0V

1.1 1.33 mA +25°C

1.1 1.33 mA +85°C

Extended devices only 1.1 TBD mA +125°C

22.2 DC Characteristics: Power-Down and Supply Current

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial) (Continued)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

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 Typ Max Units Conditions

Legend: TBD = To Be Determined. Shading of rows is to assist in readability of the table.

Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured

with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that

add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.).

2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin

loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have

an impact on the current consumption.

The test conditions for all IDD measurements in active operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS;

MCLR = VDD; WDT enabled/disabled as specified.

3: Low-power Timer1 oscillator selected.

4: BOR and LVD enable internal band gap reference. With both modules enabled, current consumption will be less

than the sum of both specifications.

PIC18F1230/1330

Supply Current (IDD)(2)

PIC18LF1230/1330 250 497 μA -40°C

VDD = 2.0V

FOSC = 1 MHz

(PRI_RUN,

EC oscillator)

260 497 μA+25°C

250 497 μA+85°C

PIC18LF1230/1330 550 750 μA -40°C

VDD = 3.0V480 750 μA+25°C

460 750 μA+85°C

All devices 1.2 3 mA -40°C

VDD = 5.0V

1.1 3 mA +25°C

1.0 3 mA +85°C

Extended devices only 1.0 TBD mA +125°C

PIC18LF1230/1330 0.72 1.93 mA -40°C

VDD = 2.0V

FOSC = 4 MHz

(PRI_RUN,

EC oscillator)

0.74 1.93 mA +25°C

0.74 1.93 mA +85°C

PIC18LF1230/1330 1.3 2.93 mA -40°C

VDD = 3.0V1.3 2.93 mA +25°C

1.3 2.93 mA +85°C

All devices 2.7 5.93 mA -40°C

VDD = 5.0V

2.6 5.93 mA +25°C

2.5 5.93 mA +85°C

Extended devices only 2.6 TBD mA +125°C

Extended devices only 8.4 TBD mA +125°C VDD = 4.2V FOSC = 25 MHz

(PRI_RUN,

EC oscillator)

11 TBD mA +125°C VDD = 5.0V

All devices 15 26 mA -40°C

VDD = 4.2V

FOSC = 40 MHz

(PRI_RUN,

EC oscillator)

16 25 mA +25°C

16 24 mA +85°C

All devices 21 39.3 mA -40°C

VDD = 5.0V21 39.3 mA +25°C

21 39.3 mA +85°C

22.2 DC Characteristics: Power-Down and Supply Current

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial) (Continued)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

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 Typ Max Units Conditions

Legend: TBD = To Be Determined. Shading of rows is to assist in readability of the table.

Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured

with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that

add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.).

2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin

loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have

an impact on the current consumption.

The test conditions for all IDD measurements in active operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS;

MCLR = VDD; WDT enabled/disabled as specified.

3: Low-power Timer1 oscillator selected.

4: BOR and LVD enable internal band gap reference. With both modules enabled, current consumption will be less

than the sum of both specifications.

PIC18F1230/1330

Supply Current (IDD)(2)

All devices 7.5 20.3 mA -40°C

VDD = 4.2V

FOSC = 4 MHz,

16 MHz internal

(PRI_RUN HS+PLL)

7.4 20.3 mA +25°C

7.3 20.3 mA +85°C

Extended devices only 8.0 TBD mA +125°C

All devices 10 20.3 mA -40°C

VDD = 5.0V

FOSC = 4 MHz,

16 MHz internal

(PRI_RUN HS+PLL)

10 20.3 mA +25°C

9.7 20.3 mA +85°C

Extended devices only 10 TBD mA +125°C

All devices 17 39.3 mA -40°C

VDD = 4.2V

FOSC = 10 MHz,

40 MHz internal

(PRI_RUN HS+PLL)

17 39.3 mA +25°C

17 39.3 mA +85°C

All devices 23 39.3 mA -40°C

VDD = 5.0V

FOSC = 10 MHz,

40 MHz internal

(PRI_RUN HS+PLL)

23 39.3 mA +25°C

23 39.3 mA +85°C

22.2 DC Characteristics: Power-Down and Supply Current

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial) (Continued)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

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 Typ Max Units Conditions

Legend: TBD = To Be Determined. Shading of rows is to assist in readability of the table.

Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured

with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that

add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.).

2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin

loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have

an impact on the current consumption.

The test conditions for all IDD measurements in active operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS;

MCLR = VDD; WDT enabled/disabled as specified.

3: Low-power Timer1 oscillator selected.

4: BOR and LVD enable internal band gap reference. With both modules enabled, current consumption will be less

than the sum of both specifications.

PIC18F1230/1330

Supply Current (IDD)(2)

PIC18LF1230/1330 65 112 μA -40°C

VDD = 2.0V

FOSC = 1 MHz

(PRI_IDLE mode,

EC oscillator)

65 112 μA+25°C

70 112 μA+85°C

PIC18LF1230/1330 120 237 μA -40°C

VDD = 3.0V120 237 μA+25°C

130 237 μA+85°C

All devices 300 360 μA -40°C

VDD = 5.0V

240 360 μA+25°C

300 360 μA+85°C

Extended devices only 320 TBD μA +125°C

PIC18LF1230/1330 260 427 μA -40°C

VDD = 2.0V

FOSC = 4 MHz

(PRI_IDLE mode,

EC oscillator)

255 427 μA+25°C

270 427 μA+85°C

PIC18LF1230/1330 420 740 μA -40°C

VDD = 3.0V430 740 μA+25°C

450 740 μA+85°C

All devices 0.9 1.23 mA -40°C

VDD = 5.0V

0.9 1.23 mA +25°C

0.9 1.23 mA +85°C

Extended devices only 1 TBD mA +125°C

Extended devices only 2.8 TBD mA +125°C VDD = 4.2V FOSC = 25 MHz

(PRI_IDLE mode,

EC oscillator)

4.3 TBD mA +125°C VDD = 5.0V

All devices 6.0 9.5 mA -40°C

VDD = 4.2V

FOSC = 40 MHz

(PRI_IDLE mode,

EC oscillator)

6.2 9.0 mA +25°C

6.6 8.6 mA +85°C

All devices 8.1 17.3 mA -40°C

VDD = 5.0V9.1 17.3 mA +25°C

8.3 17.3 mA +85°C

22.2 DC Characteristics: Power-Down and Supply Current

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial) (Continued)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

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 Typ Max Units Conditions

Legend: TBD = To Be Determined. Shading of rows is to assist in readability of the table.

Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured

with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that

add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.).

2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin

loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have

an impact on the current consumption.

The test conditions for all IDD measurements in active operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS;

MCLR = VDD; WDT enabled/disabled as specified.

3: Low-power Timer1 oscillator selected.

4: BOR and LVD enable internal band gap reference. With both modules enabled, current consumption will be less

than the sum of both specifications.

PIC18F1230/1330

Supply Current (IDD)(2)

PIC18LF1230/1330 14 39.6 μA -40°C

VDD = 2.0V

FOSC = 32 kHz(4)

(SEC_RUN mode,

Timer1 as clock)

15 39.6 μA+25°C

16 39.6 μA+85°C

PIC18LF1230/1330 40 64 μA -40°C

VDD = 3.0V35 64 μA+25°C

31 64 μA+85°C

All devices 99 147 μA -40°C

VDD = 5.0V81 147 μA+25°C

75 147 μA+85°C

PIC18LF1230/1330 2.5 11.6 μA -40°C

VDD = 2.0V

FOSC = 32 kHz(4)

(SEC_IDLE mode,

Timer1 as clock)

3.7 11.6 μA+25°C

4.5 11.6 μA+85°C

PIC18LF1230/1330 5.0 14.6 μA -40°C

VDD = 3.0V5.4 14.6 μA+25°C

6.3 14.6 μA+85°C

All devices 8.5 24.6 μA -40°C

VDD = 5.0V9.0 24.6 μA+25°C

10.5 24.6 μA+85°C

22.2 DC Characteristics: Power-Down and Supply Current

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial) (Continued)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

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 Typ Max Units Conditions

Legend: TBD = To Be Determined. Shading of rows is to assist in readability of the table.

Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured

with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that

add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.).

2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin

loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have

an impact on the current consumption.

The test conditions for all IDD measurements in active operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS;

MCLR = VDD; WDT enabled/disabled as specified.

3: Low-power Timer1 oscillator selected.

4: BOR and LVD enable internal band gap reference. With both modules enabled, current consumption will be less

than the sum of both specifications.

PIC18F1230/1330

Module Differential Currents (ΔIWDT, ΔIBOR, ΔILVD, ΔIOSCB, ΔIAD)

D022

(ΔIWDT)

Watchdog Timer 1.3 4.8 μA -40°C

VDD = 2.0V1.4 5.4 μA+25°C

2.0 5.4 μA+85°C

1.9 5.6 μA -40°C

VDD = 3.0V2.0 6.2 μA+25°C

2.8 6.2 μA+85°C

4.0 9.6 μA -40°C

VDD = 5.0V

5.5 9.6 μA+25°C

5.6 9.6 μA+85°C

13 13 μA +125°C

D022A

(ΔIBOR)

Brown-out Reset(4) 35 54.6 μA -40°C to +85°C VDD = 3.0V

40 64.6 μA -40°C to +85°C

VDD = 5.0V

55 44 μA -40°C to +125°C

044μA -40°C to +85°C Sleep mode,

BOREN1:BOREN0 = 10

044μA -40°C to +125°C

D022B

(ΔILVD)

Low-Voltage Detect(4) 22 37.6 μA -40°C to +85°C VDD = 2.0V

25 39.6 μA -40°C to +85°C VDD = 3.0V

29 44.6 μA -40°C to +85°C VDD = 5.0V

30 54.6 μA -40°C to +125°C

D025

(ΔIOSCB)

Timer1 Oscillator 2.1 5.5 μA -40°C

VDD = 2.0V 32 kHz on Timer1(3)

1.8 6.1 μA+25°C

2.1 6.1 μA+85°C

2.2 7 μA -40°C

VDD = 3.0V 32 kHz on Timer1(3)

2.6 7.6 μA+25°C

2.9 7.6 μA+85°C

3.0 7.6 μA -40°C

VDD = 5.0V 32 kHz on Timer1(3)

3.2 7.6 μA+25°C

3.4 7.6 μA+85°C

22.2 DC Characteristics: Power-Down and Supply Current

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial) (Continued)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

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 Typ Max Units Conditions

Legend: TBD = To Be Determined. Shading of rows is to assist in readability of the table.

Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured

with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that

add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.).

2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin

loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have

an impact on the current consumption.

The test conditions for all IDD measurements in active operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS;

MCLR = VDD; WDT enabled/disabled as specified.

3: Low-power Timer1 oscillator selected.

4: BOR and LVD enable internal band gap reference. With both modules enabled, current consumption will be less

than the sum of both specifications.

PIC18F1230/1330

Module Differential Currents (ΔIWDT, ΔIBOR, ΔILVD, ΔIOSCB, ΔIAD)

D026

(ΔIAD)

A/D Converter 1.0 1.6 μA -40°C to +85°C VDD = 2.0V

A/D on, not converting

1.0 1.6 μA -40°C to +85°C VDD = 3.0V

1.0 1.6 μA -40°C to +85°C VDD = 5.0V

2.0 7.6 μA -40°C to +125°C

22.2 DC Characteristics: Power-Down and Supply Current

PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial) (Continued)

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial, Extended)

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 Typ Max Units Conditions

Legend: TBD = To Be Determined. Shading of rows is to assist in readability of the table.

Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured

with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that

add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.).

2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin

loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have

an impact on the current consumption.

The test conditions for all IDD measurements in active operation mode are:

OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD or VSS;

MCLR = VDD; WDT enabled/disabled as specified.

3: Low-power Timer1 oscillator selected.

4: BOR and LVD enable internal band gap reference. With both modules enabled, current consumption will be less

than the sum of both specifications.

PIC18F1230/1330

22.3 DC Characteristics: PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial)

DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param

No. Symbol Characteristic Min Max Units Conditions

VIL Input Low Voltage

I/O ports:

D030 with TTL buffer VSS 0.15 VDD VVDD < 4.5V

D030A — 0.8 V 4.5V ≤ VDD ≤ 5.5V

D031 with Schmitt Trigger buffer VSS 0.2 VDD V

D032 MCLR VSS 0.2 VDD V

D033 OSC1 VSS 0.3 VDD V HS, HSPLL modes

D033A

D033B

D034

OSC1

T1CKI

VSS

0.2 VDD

0.3

RC, EC modes(1)

XT, LP modes

VIH Input High Voltage

I/O ports:

D040 with TTL buffer 0.25 VDD + 0.8V VDD VVDD < 4.5V

D040A 2.0 VDD V4.5V ≤ VDD ≤ 5.5V

D041 with Schmitt Trigger buffer 0.8 VDD VDD V

D042 MCLR 0.8 VDD VDD V

D043 OSC1 0.7 VDD VDD V HS, HSPLL modes

D043A

D043B

D043C

D044

OSC1

T1CKI

0.8 VDD

0.9 VDD

1.6

VDD

EC mode

RC mode(1)

XT, LP modes

IIL Input Leakage Current(2,3)

D060 I/O ports — ±1μAVSS ≤ VPIN ≤ VDD,

Pin at high-impedance

D061 MCLR —±5μAVss ≤ VPIN ≤ VDD

D063 OSC1 — ±5μAVss ≤ VPIN ≤ VDD

IPU Weak Pull-up Current

D070 IPURB PORTB weak pull-up current 50 400 μAVDD = 5V, VPIN = VSS

Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the

PIC® device be driven with an external clock while in RC mode.

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: Negative current is defined as current sourced by the pin.

4: Parameter is characterized but not tested.

PIC18F1230/1330

VOL Output Low Voltage

D080 I/O ports — 0.6 V IOL = 8.5 mA, VDD = 4.5V,

-40°C to +85°C

D083 OSC2/CLKO

(RC, RCIO, EC, ECIO modes)

—0.6VI

OL = 1.6 mA, VDD = 4.5V,

-40°C to +85°C

VOH Output High Voltage(3)

D090 I/O ports VDD – 0.7 — V IOH = -3.0 mA, VDD =

4.5V,

-40°C to +85°C

D092 OSC2/CLKO

(RC, RCIO, EC, ECIO modes)

VDD – 0.7 — V IOH = -1.3 mA, VDD =

4.5V,

-40°C to +85°C

Capacitive Loading Specs

on Output Pins

D100(4) COSC2 OSC2 pin — 15 pF In XT, HS and LP modes

when external clock is

used to drive OSC1

D101 CIO All I/O pins and OSC2

(in RC mode)

— 50 pF To meet the AC Timing

Specifications

22.3 DC Characteristics: PIC18F1230/1330 (Industrial)

PIC18LF1230/1330 (Industrial) (Continued)

DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param

No. Symbol Characteristic Min Max Units Conditions

Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the

PIC® device be driven with an external clock while in RC mode.

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: Negative current is defined as current sourced by the pin.

4: Parameter is characterized but not tested.

PIC18F1230/1330

TABLE 22-1: MEMORY PROGRAMMING REQUIREMENTS

DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ T

A ≤ +85°C for industrial

Param

No. Sym Characteristic Min Typ† Max Units Conditions

Data EEPROM Memory

D120 EDByte Endurance 100K 1M — E/W -40°C to +85°C

D121 VDRW VDD for Read/Write VMIN — 5.5 V Using EECON to read/write

VMIN = Minimum operating

voltage

D122 TDEW Erase/Write Cycle Time — 4 — ms

D123 TRETD Characteristic Retention 40 — — Year Provided no other

specifications are violated

D124 TREF Number of Total Erase/Write

Cycles before Refresh(1)

1M 10M — E/W -40°C to +85°C

D125 IDDP Supply Current during

Programming

—10—mA

Program Flash Memory

D130 EPCell Endurance 10K 100K — E/W -40°C to +85°C

D131 VPR VDD for Read VMIN —5.5VVMIN = Minimum operating

voltage

D132B VPEW VDD for Self-Timed Write VMIN —5.5VVMIN = Minimum operating

voltage

D133A TIW Self-Timed Write Cycle Time — 2 — ms

D134 TRETD Characteristic Retention 40 100 — Year Provided no other

specifications are violated

D135 IDDP Supply Current during

Programming

—10—mA

† Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance

only and are not tested.

Note 1: Refer to Section 7.8 “Using the Data EEPROM” for a more detailed discussion on data EEPROM

endurance.

PIC18F1230/1330

TABLE 22-2: COMPARATOR SPECIFICATIONS

TABLE 22-3: VOLTAGE REFERENCE SPECIFICATIONS

Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +85°C (unless otherwise stated).

Param

No. Sym Characteristics Min Typ Max Units Comments

D300 VIOFF Input Offset Voltage — ±5.0 ±10 mV

D301 VICM Input Common Mode Voltage 0 — VDD – 1.5 V

D302 CMRR Common Mode Rejection Ratio 55 — — dB

300 TRESP Response Time(1) — 150 400 ns PIC18FXXXX

300A — 150 600 ns PIC18LFXXXX,

VDD = 2.0V

301 TMC2OV Comparator Mode Change to

Output Valid

—— 10 μs

Note 1: Response time measured with one comparator input at (VDD – 1.5)/2, while the other input transitions

from VSS to VDD.

Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +85°C (unless otherwise stated).

Param

No. Sym Characteristics Min Typ Max Units Comments

D310 VRES Resolution VDD/24 — VDD/32 LSb

D311 VRAA Absolute Accuracy — — 1/2 LSb

D312 VRUR Unit Resistor Value (R) — 2k — Ω

310 TSET Settling Time(1) — — 10 μs

Note 1: Settling time measured while CVRR = 1 and CVR3:CVR0 transitions from ‘0000’ to ‘1111’.

PIC18F1230/1330

FIGURE 22-4: LOW-VOLTAGE DETECT CHARACTERISTICS

TABLE 22-4: LOW-VOLTAGE DETECT CHARACTERISTICS

VLVD

LVDIF

VDD

(LVDIF set by hardware)

(LVDIF can be

cleared in software)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param

No. Sym Characteristic Min Typ Max Units Conditions

D420 LVD Voltage on VDD

Transition High-to-Low

LVDL<3:0> = 0000 2.06 2.17 2.28 V

LVDL<3:0> = 0001 2.12 2.23 2.34 V

LVDL<3:0> = 0010 2.24 2.36 2.48 V

LVDL<3:0> = 0011 2.32 2.44 2.56 V

LVDL<3:0> = 0100 2.47 2.60 2.73 V

LVDL<3:0> = 0101 2.65 2.79 2.93 V

LVDL<3:0> = 0110 2.74 2.89 3.04 V

LVDL<3:0> = 0111 2.96 3.12 3.28 V

LVDL<3:0> = 1000 3.22 3.39 3.56 V

LVDL<3:0> = 1001 3.37 3.55 3.73 V

LVDL<3:0> = 1010 3.52 3.71 3.90 V

LVDL<3:0> = 1011 3.70 3.90 4.10 V

LVDL<3:0> = 1100 3.90 4.11 4.32 V

LVDL<3:0> = 1101 4.11 4.33 4.55 V

LVDL<3:0> = 1110 4.36 4.59 4.82 V

PIC18F1230/1330

22.4 AC (Timing) Characteristics

22.4.1 TIMING PARAMETER SYMBOLOGY

The timing parameter symbols have been created

using one of the following formats:

1. TppS2ppS 3. TCC:ST (I2C specifications only)

2. TppS 4. Ts (I2C specifications only)

F Frequency T Time

Lowercase letters (pp) and their meanings:

cc CCP1 osc OSC1

ck CLKO rd RD

cs CS rw RD or WR

di SDI sc SCK

do SDO ss SS

dt Data in t0 T0CKI

io I/O port t1 T13CKI

mc MCLR wr WR

Uppercase letters and their meanings:

F Fall P Period

HHigh RRise

I Invalid (High-impedance) V Valid

L Low Z High-impedance

I2C only

AA output access High High

BUF Bus free Low Low

TCC:ST (I2C specifications only)

HD Hold SU Setup

DAT DATA input hold STO Stop condition

STA Start condition

PIC18F1230/1330

22.4.2 TIMING CONDITIONS

The temperature and voltages specified in Table 22-5

apply to all timing specifications unless otherwise

noted. Figure 22-5 specifies the load conditions for the

timing specifications.

TABLE 22-5: TEMPERATURE AND VOLTAGE SPECIFICATIONS – AC

FIGURE 22-5: LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS

Note: Because of space limitations, the generic

terms “PIC18FXXXX” and “PIC18LFXXXX”

are used throughout this section to refer to

the PIC18F1230/1330 and PIC18LF1230/

1330 families of devices specifically and

only those devices.

AC CHARACTERISTICS

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Operating voltage VDD range as described in DC spec Section 22.1 and

Section 22.3.

LF parts operate for industrial temperatures only.

VDD/2

VSS

RL=464Ω

CL= 50 pF for all pins except OSC2/CLKO and including D and E outputs as ports

Load Condition 1 Load Condition 2

PIC18F1230/1330

22.4.3 TIMING DIAGRAMS AND SPECIFICATIONS

FIGURE 22-6: EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL)

TABLE 22-6: EXTERNAL CLOCK TIMING REQUIREMENTS

Param.

No. Symbol Characteristic Min Max Units Conditions

1A FOSC External CLKI Frequency(1) DC 1 MHz XT, RC Oscillator modes

DC 20 MHz HS Oscillator mode

DC 31.25 kHz LP Oscillator mode

Oscillator Frequency(1) DC 4 MHz RC Oscillator mode

0.1 4 MHz XT Oscillator mode

4 20 MHz HS Oscillator mode

5 200 kHz LP Oscillator mode

OSC External CLKI Period(1) 1000 — ns XT, RC Oscillator modes

50 — ns HS Oscillator mode

32 — μs LP Oscillator mode

Oscillator Period(1) 250 — ns RC Oscillator mode

250 1 μs XT Oscillator mode

100 250 ns HS Oscillator mode

50 250 ns HS Oscillator mode

5—μs LP Oscillator mode

CY Instruction Cycle Time(1) 100 — ns TCY = 4/FOSC, Industrial

160 — ns T

CY = 4/FOSC, Extended

3TOSL,

TOSH

External Clock in (OSC1)

High or Low Time

30 — ns XT Oscillator mode

2.5 — μs LP Oscillator mode

10 — ns HS Oscillator mode

OSR,

TOSF

External Clock in (OSC1)

Rise or Fall Time

— 20 ns XT Oscillator mode

— 50 ns LP Oscillator mode

— 7.5 ns HS Oscillator mode

Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period for all configurations

except PLL. All specified values are based on characterization data for that particular oscillator type under

standard operating conditions with the device executing code. Exceeding these specified limits may result

in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested

to operate at “min.” values with an external clock applied to the OSC1/CLKI pin. When an external clock

input is used, the “max.” cycle time limit is “DC” (no clock) for all devices.

OSC1

CLKO

Q4 Q1 Q2 Q3 Q4 Q1

33 44

PIC18F1230/1330

TABLE 22-7: PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2V TO 5.5V)

TABLE 22-8: AC CHARACTERISTICS: INTERNAL RC ACCURACY

PIC18F1230/1330 (INDUSTRIAL)

PIC18LF1230/1330 (INDUSTRIAL)

Param

No. Sym Characteristic Min Typ† Max Units Conditions

F10 FOSC Oscillator Frequency Range 4 — 10 MHz HS mode only

F11 FSYS On-Chip VCO System Frequency 16 — 40 MHz HS mode only

F12 trc PLL Start-up Time (Lock Time) — — 2 ms

F13 ΔCLK CLKO Stability (Jitter) -2 — +2 %

† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance

only and are not tested.

PIC18LF1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC18F1230/1330

(Industrial)

Standard Operating Conditions (unless otherwise stated)

Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param

No. Device Min Typ Max Units Conditions

INTOSC Accuracy @ Freq = 8 MHz, 4 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz, 125 kHz, 31 kHz(1)

PIC18LF1230/1330 -2 +/-1 2 % +25°C VDD = 2.7-3.3V

-5 — 5 % -10°C to +85°C VDD = 2.7-3.3V

-10 +/-1 10 % -40°C to +85°C VDD = 2.7-3.3V

PIC18F1230/1330 -2 +/-1 2 % +25°C VDD = 4.5-5.5V

-5 — 5 % -10°C to +85°C VDD = 4.5-5.5V

-10 +/-1 10 %-40°C to +85°C VDD = 4.5-5.5V

INTRC Accuracy @ Freq = 31 kHz(2,3)

PIC18LF1230/1330 26.562 — 35.938 kHz -40°C to +85°C VDD = 2.7-3.3V

PIC18F1230/1330 26.562 —35.938 kHz -40°C to +85°C VDD = 4.5-5.5V

Legend: Shading of rows is to assist in readability of the table.

Note 1: Frequency calibrated at 25°C. OSCTUNE register can be used to compensate for temperature drift.

2: INTRC frequency after calibration.

3: Change of INTRC frequency as VDD changes.

PIC18F1230/1330

FIGURE 22-7: CLKO AND I/O TIMING

TABLE 22-9: CLKO AND I/O TIMING REQUIREMENTS

Param

No. Symbol Characteristic Min Typ Max Units Conditions

10 TosH2ckL OSC1 ↑ to CLKO ↓ — 75 200 ns (Note 1)

11 TosH2ckH OSC1 ↑ to CLKO ↑ — 75 200 ns (Note 1)

12 TckR CLKO Rise Time — 35 100 ns (Note 1)

13 TckF CLKO Fall Time — 35 100 ns (Note 1)

14 TckL2ioV CLKO ↓ to Port Out Valid — — 0.5 TCY + 20 ns (Note 1)

15 TioV2ckH Port In Valid before CLKO ↑ 0.25 TCY + 25 — — ns (Note 1)

16 TckH2ioI Port In Hold after CLKO ↑ 0——ns(Note 1)

17 TosH2ioV OSC1 ↑ (Q1 cycle) to Port Out Valid — 50 150 ns

18 TosH2ioI OSC1 ↑ (Q2 cycle) to Port

Input Invalid (I/O in hold time)

PIC18FXXXX 100 — — ns

18A PIC18LFXXXX 200 — — ns VDD = 2.0V

19 TioV2osH Port Input Valid to OSC1 ↑ (I/O in setup time) 0 — — ns

20 TioR Port Output Rise Time PIC18FXXXX — 10 25 ns

20A PIC18LFXXXX — — 60 ns VDD = 2.0V

21 TioF Port Output Fall Time PIC18FXXXX — 10 25 ns

21A PIC18LFXXXX — — 60 ns VDD = 2.0V

22† TINP INTx Pin High or Low Time TCY ——ns

23† TRBP RB7:RB4 Change INTx High or Low Time TCY ——ns

† These parameters are asynchronous events not related to any internal clock edges.

Note 1: Measurements are taken in RC mode, where CLKO output is 4 x TOSC.

Note: Refer to Figure 22-5 for load conditions.

OSC1

CLKO

I/O pin

(Input)

I/O pin

(Output)

Q4 Q1 Q2 Q3

13 14

20, 21

19 18

Old Value New Value

PIC18F1230/1330

FIGURE 22-8: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND

POWER-UP TIMER TIMING

FIGURE 22-9: BROWN-OUT RESET TIMING

TABLE 22-10: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER

AND BROWN-OUT RESET REQUIREMENTS

Param.

No. Symbol Characteristic Min Typ Max Units Conditions

30 TmcL MCLR Pulse Width (low) 2 — — μs

31 TWDT Watchdog Timer Time-out Period

(no postscaler)

3.4 4.0 4.6 ms

32 TOST Oscillation Start-up Timer Period 1024 TOSC — 1024 TOSC —TOSC = OSC1 period

33 TPWRT Power-up Timer Period 55.6 65.5 75 ms

34 TIOZ I/O High-Impedance from MCLR

Low or Watchdog Timer Reset

—2—μs

35 TBOR Brown-out Reset Pulse Width 200 — — μsVDD ≤ BVDD (see D005)

36 TIRVST Time for Internal Reference

Voltage to become Stable

—2050 μs

37 TLVD Low-Voltage Detect Pulse Width 200 — — μsVDD ≤ VLVD

38 TCSD CPU Start-up Time — 10 — μs

39 TIOBST Time for INTOSC to Stabilize — 1 — μs

VDD

MCLR

Internal

POR

PWRT

Time-out

Oscillator

Time-out

Internal

Reset

Watchdog

Timer

Reset

I/O pins

Note: Refer to Figure 22-5 for load conditions.

VDD BVDD

VIRVST

Enable Internal

Internal Reference 36

Reference Voltage

Voltage Stable

PIC18F1230/1330

FIGURE 22-10: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS

TABLE 22-11: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS

Param

No. Symbol Characteristic Min Max Units Conditions

40 Tt0H T0CKI High Pulse Width No prescaler 0.5 TCY + 20 — ns

With prescaler 10 — ns

41 Tt0L T0CKI Low Pulse Width No prescaler 0.5 TCY + 20 — ns

With prescaler 10 — ns

42 Tt0P T0CKI Period No prescaler TCY + 10 — ns

With prescaler Greater of:

20 ns or

CY + 40)/N

— ns N = prescale

value

(1, 2, 4,..., 256)

45 Tt1H T1CKI High

Time

Synchronous, no prescaler 0.5 TCY + 20 — ns

Synchronous,

with prescaler

PIC18FXXXX 10 — ns

PIC18LFXXXX 25 — ns VDD = 2.0V

Asynchronous PIC18FXXXX 30 — ns

PIC18LFXXXX 50 — ns VDD = 2.0V

46 Tt1L T1CKI Low

Time

Synchronous, no prescaler 0.5 TCY + 5 — ns

Synchronous,

with prescaler

PIC18FXXXX 10 — ns

PIC18LFXXXX 25 — ns VDD = 2.0V

Asynchronous PIC18FXXXX 30 — ns

PIC18LFXXXX 50 — ns VDD = 2.0V

47 Tt1P T1CKI Input

Period

Synchronous Greater of:

20 ns or

(TCY + 40)/N

— ns N = prescale

value (1, 2, 4, 8)

Asynchronous 60 — ns

Ft1 T1CKI Oscillator Input Frequency Range DC 50 kHz

48 Tcke2tmrI Delay from External T1CKI Clock Edge to Timer

Increment

2 TOSC 7 TOSC —

Note: Refer to Figure 22-5 for load conditions.

T0CKI

T1OSO/T1CKI

TMR0 or TMR1

PIC18F1230/1330

FIGURE 22-11: EUSART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING

TABLE 22-12: EUSART SYNCHRONOUS TRANSMISSION REQUIREMENTS

FIGURE 22-12: EUSART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING

TABLE 22-13: EUSART SYNCHRONOUS RECEIVE REQUIREMENTS

Param

No. Symbol Characteristic Min Max Units Conditions

120 TckH2dtV SYNC XMIT (MASTER & SLAVE)

Clock High to Data Out Valid PIC18FXXXX — 40 ns

PIC18LFXXXX — 100 ns VDD = 2.0V

121 Tckrf Clock Out Rise Time and Fall Time

(Master mode)

PIC18FXXXX — 20 ns

PIC18LFXXXX — 50 ns VDD = 2.0V

122 Tdtrf Data Out Rise Time and Fall Time PIC18FXXXX — 20 ns

PIC18LFXXXX — 50 ns VDD = 2.0V

Param.

No. Symbol Characteristic Min Max Units Conditions

125 TdtV2ckl SYNC RCV (MASTER & SLAVE)

Data Hold before CK ↓ (DT hold time) 10 — ns

126 TckL2dtl Data Hold after CK ↓ (DT hold time) 15 — ns

121 121

120 122

RA2/TX/CK

RA3/RX/DT

Note: Refer to Figure 22-5 for load conditions.

125

126

RA2/TX/CK

RA3/RX/DT

Note: Refer to Figure 22-5 for load conditions.

PIC18F1230/1330

TABLE 22-14: A/D CONVERTER CHARACTERISTICS: PIC18F1230/1330 (INDUSTRIAL)

PIC18LF1230/1330 (INDUSTRIAL)

Param

No. Symbol Characteristic Min Typ Max Units Conditions

A01 NRResolution — — 10 bit ΔVREF ≥ 3.0V

A03 EIL Integral Linearity Error — — < ±1 LSb ΔVREF ≥ 3.0V

A04 EDL Differential Linearity Error — — < ±1 LSb ΔVREF ≥ 3.0V

A06 EOFF Offset Error — — < ±2 LSb ΔVREF ≥ 3.0V

A07 EGN Gain Error — — < ±1 LSb ΔVREF ≥ 3.0V

A10 — Monotonicity Guaranteed(1) —VSS ≤ VAIN ≤ VREF

A20 ΔVREF Reference Voltage Range

(VREF+ – VSS)

1.8

—

VDD < 3.0V

VDD ≥ 3.0V

A21 VREF+ Positive Reference Voltage VSS —VREF+V

A25 VAIN Analog Input Voltage VSS —VREF+V

A30 ZAIN Recommended Impedance of

Analog Voltage Source

—— 2.5kΩ

A50 IREF VREF+ Input Current(2) —

—

150

μA

During VAIN acquisition.

During A/D conversion

cycle.

Note 1: The A/D conversion result never decreases with an increase in the input voltage and has no missing codes.

2: VREF+ current is from RA4/T0CKI/AN2/VREF+ pin or VDD, whichever is selected as the VREF+ source.

PIC18F1230/1330

FIGURE 22-13: A/D CONVERSION TIMING

TABLE 22-15: A/D CONVERSION REQUIREMENTS

Param

No. Symbol Characteristic Min Max Units Conditions

130 TAD A/D Clock Period PIC18FXXXX 0.7 25.0(1) μsTOSC based, VREF ≥ 3.0V

PIC18LFXXXX 1.4 25.0(1) μsVDD = 2.0V,

TOSC based, VREF full range

PIC18FXXXX TBD 1 μs A/D RC mode

PIC18LFXXXX TBD 3 μsV

DD = 2.0V, A/D RC mode

131 TCNV Conversion Time

(not including acquisition time)(2)

11 12 TAD

132 TACQ Acquisition Time(3) 1.4

TBD

—

μs

-40°C to +85°C

0°C ≤ to ≤ +85°C

135 TSWC Switching Time from Convert → Sample — (Note 4)

TBD TDIS Discharge Time 0.2 — μs

Legend: TBD = To Be Determined

Note 1: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider.

2: ADRES register may be read on the following TCY cycle.

3: The time for the holding capacitor to acquire the “New” input voltage when the voltage changes full scale

after the conversion (VDD to VSS or VSS to VDD). The source impedance (RS) on the input channels is 50Ω.

4: On the following cycle of the device clock.

131

130

132

BSF ADCON0, GO

A/D CLK(1)

A/D DATA

ADRES

ADIF

SAMPLE

OLD_DATA

SAMPLING STOPPED

DONE

NEW_DATA

(Note 2)

98 7 2 1 0

Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction

to be executed.

2: This is a minimal RC delay (typically 100 ns), which also disconnects the holding capacitor from the analog input.

. . . . . .

TCY

PIC18F1230/1330

NOTES:

PIC18F1230/1330

23.0 DC AND AC

CHARACTERISTICS GRAPHS

AND TABLES

Graphs and tables are not available at this time.

PIC18F1230/1330

NOTES:

PIC18F1230/1330

24.0 PACKAGING INFORMATION

24.1 Package Marking Information

18-Lead PDIP

XXXXXXXXXXXXXXXXX

YYWWNNN

Example

PIC18F1330-I/P

0710017

18-Lead SOIC

XXXXXXXXXXXX

YYWWNNN

Example

PIC18F1230-

E/SO

0710017

20-Lead SSOP

XXXXXXXXXXX

YYWWNNN

Example

PIC18F1230-

E/SS

0710017

28-Lead QFN

XXXXXXXX

YYWWNNN

Example

18F1330

-I/ML

0710017

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.

PIC18F1230/1330

24.2 Package Details

The following sections give the technical details of the packages.

18-Lead Plastic Dual In-Line (P) – 300 mil Body [PDIP]

Notes:

1. Pin 1 visual index feature may vary, but must be located within the hatched area.

2. § Significant Characteristic.

3. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" per side.

4. Dimensioning and tolerancing per ASME Y14.5M.

BSC: Basic Dimension. Theoretically exact value shown without tolerances.

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

Units INCHES

Dimension Limits MIN NOM MAX

Number of Pins N 18

Pitch e .100 BSC

Top to Seating Plane A – – .210

Molded Package Thickness A2 .115 .130 .195

Base to Seating Plane A1 .015 – –

Shoulder to Shoulder Width E .300 .310 .325

Molded Package Width E1 .240 .250 .280

Overall Length D .880 .900 .920

Tip to Seating Plane L .115 .130 .150

Lead Thickness c .008 .010 .014

Upper Lead Width b1 .045 .060 .070

Lower Lead Width b .014 .018 .022

Overall Row Spacing § eB – – .430

NOTE 1

123

Microchip Technology Drawing C04-007B

PIC18F1230/1330

18-Lead Plastic Small Outline (SO) – Wide, 7.50 mm Body [SOIC]

Notes:

1. Pin 1 visual index feature may vary, but must be located within the hatched area.

2. § Significant Characteristic.

3. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.15 mm per side.

4. Dimensioning and tolerancing per ASME Y14.5M.

BSC: Basic Dimension. Theoretically exact value shown without tolerances.

REF: Reference Dimension, usually without tolerance, for information purposes only.

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

Units MILLIMETERS

Dimension Limits MIN NOM MAX

Number of Pins N 18

Pitch e 1.27 BSC

Overall Height A – – 2.65

Molded Package Thickness A2 2.05 – –

Standoff § A1 0.10 – 0.30

Overall Width E 10.30 BSC

Molded Package Width E1 7.50 BSC

Overall Length D 11.55 BSC

Chamfer (optional) h 0.25 – 0.75

Foot Length L 0.40 – 1.27

Footprint L1 1.40 REF

Foot Angle φ0° – 8°

Lead Thickness c 0.20 – 0.33

Lead Width b 0.31 – 0.51

Mold Draft Angle Top α5° – 15°

Mold Draft Angle Bottom β5° – 15°

NOTE 1

123

Microchip Technology Drawing C04-051B

PIC18F1230/1330

20-Lead Plastic Shrink Small Outline (SS) – 5.30 mm Body [SSOP]

Notes:

1. Pin 1 visual index feature may vary, but must be located within the hatched area.

2. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.20 mm per side.

3. Dimensioning and tolerancing per ASME Y14.5M.

BSC: Basic Dimension. Theoretically exact value shown without tolerances.

REF: Reference Dimension, usually without tolerance, for information purposes only.

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

Units MILLIMETERS

Dimension Limits MIN NOM MAX

Number of Pins N 20

Pitch e 0.65 BSC

Overall Height A – – 2.00

Molded Package Thickness A2 1.65 1.75 1.85

Standoff A1 0.05 – –

Overall Width E 7.40 7.80 8.20

Molded Package Width E1 5.00 5.30 5.60

Overall Length D 6.90 7.20 7.50

Foot Length L 0.55 0.75 0.95

Footprint L1 1.25 REF

Lead Thickness c 0.09 – 0.25

Foot Angle φ0° 4° 8°

Lead Width b 0.22 – 0.38

NOTE 1

Microchip Technology Drawing C04-072B

PIC18F1230/1330

28-Lead Plastic Quad Flat, No Lead Package (ML) – 6x6 mm Body [QFN]

with 0.55 mm Contact Length

Notes:

1. Pin 1 visual index feature may vary, but must be located within the hatched area.

2. Package is saw singulated.

3. Dimensioning and tolerancing per ASME Y14.5M.

BSC: Basic Dimension. Theoretically exact value shown without tolerances.

REF: Reference Dimension, usually without tolerance, for information purposes only.

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

Units MILLIMETERS

Dimension Limits MIN NOM MAX

Number of Pins N 28

Pitch e 0.65 BSC

Overall Height A 0.80 0.90 1.00

Standoff A1 0.00 0.02 0.05

Contact Thickness A3 0.20 REF

Overall Width E 6.00 BSC

Exposed Pad Width E2 3.65 3.70 4.20

Overall Length D 6.00 BSC

Exposed Pad Length D2 3.65 3.70 4.20

Contact Width b 0.23 0.30 0.35

Contact Length L 0.50 0.55 0.70

Contact-to-Exposed Pad K 0.20 – –

DEXPOSED D2

NOTE 1

TOP VIEW BOTTOM VIEW

PAD

Microchip Technology Drawing C04-105B

PIC18F1230/1330

NOTES:

PIC18F1230/1330

APPENDIX A: REVISION HISTORY

Revision A (November 2005)

Original data sheet for PIC18F1230/1330 devices.

Revision B (February 2006)

Data bank information was updated and a note was

added for calculating the PCPWM duty cycle.

Revision C (March 2007)

Updated Section 22.0 “Electrical Characteristics”

and Section 24.0 “Packaging Information”.

APPENDIX B: DEVICE

DIFFERENCES

The differences between the devices listed in this data

sheet are shown in Table B-1.

TABLE B-1: DEVICE DIFFERENCES

Features PIC18F1230 PIC18F1330

Program Memory (Bytes) 4096 8192

Program Memory (Instructions) 2048 4096

Packages 18-Pin PDIP

18-Pin SOIC

20-Pin SSOP

28-Pin QFN

18-Pin PDIP

18-Pin SOIC

20-Pin SSOP

28-Pin QFN

PIC18F1230/1330

APPENDIX C: CONVERSION

CONSIDERATIONS

This appendix discusses the considerations for

converting from previous versions of a device to the

ones listed in this data sheet. Typically, these changes

are due to the differences in the process technology

used. An example of this type of conversion is from a

PIC16C74A to a PIC16C74B.

Not Applicable

APPENDIX D: MIGRATION FROM

BASELINE TO

ENHANCED DEVICES

This section discusses how to migrate from a Baseline

device (i.e., PIC16C5X) to an Enhanced MCU device

(i.e., PIC18FXXX).

The following are the list of modifications over the

PIC16C5X microcontroller family:

Not Currently Available

PIC18F1230/1330

APPENDIX E: MIGRATION FROM

MID-RANGE TO

ENHANCED DEVICES

A detailed discussion of the differences between the

mid-range MCU devices (i.e., PIC16CXXX) and the

Enhanced devices (i.e., PIC18FXXX) is provided in

AN716, “Migrating Designs from PIC16C74A/74B to

PIC18C442”

. The changes discussed, while device

specific, are generally applicable to all mid-range to

Enhanced device migrations.

This Application Note is available as Literature Number

DS00716.

APPENDIX F: MIGRATION FROM

HIGH-END TO

ENHANCED DEVICES

A detailed discussion of the migration pathway and

differences between the high-end MCU devices (i.e.,

PIC17CXXX) and the Enhanced devices (i.e.,

PIC18FXXX) is provided in

AN726, “PIC17CXXX to

PIC18CXXX Migration”

This Application Note is available as Literature Number

DS00726.

PIC18F1230/1330

NOTES:

© 2007 Microchip Technology Inc. Advance Information DS39758C-page 299
PIC18F1230/1330
INDEX
A
A/D ................................................................................... 163
A/D Converter Interrupt, Configuring  ....................... 167
Acquisition Requirements  ........................................ 168
ADCON0 Register .................................................... 163
ADCON1 Register .................................................... 163
ADCON2 Register .................................................... 163
ADRESH Register ............................................ 163, 166
ADRESL Register  .................................................... 163
Analog Port Pins, Configuring .................................. 170
Associated Registers  ............................................... 172
Configuring the Module ............................................ 167
Conversion Clock (TAD) ........................................... 169
Conversion Requirements  ....................................... 285
Conversion Status (GO/DONE Bit)  .......................... 166
Conversions ............................................................. 171
Converter Characteristics  ........................................ 284
Discharge ................................................................. 171
Operation in Power-Managed Modes  ...................... 170
Selecting and Configuring Acquisition Time  ............ 169
Triggering Conversions ............................................ 168
Absolute Maximum Ratings  ............................................. 257
AC (Timing) Characteristics  ............................................. 276
Conditions ................................................................ 277
Load Conditions for Device 
Timing Specifications  ....................................... 277
Parameter Symbology  ............................................. 276
Temperature and Voltage Specifications ................. 277
AC Characteristics
Internal RC Accuracy  ............................................... 279
Access Bank
Mapping with Indexed Literal Offset 
Addressing Mode ............................................... 63
Remapping with Indexed Literal Offset 
Addressing Mode ............................................... 63
ADCON0 Register ............................................................ 163
GO/DONE Bit ........................................................... 166
ADCON1 Register ............................................................ 163
ADCON2 Register ............................................................ 163
ADDFSR .......................................................................... 250
ADDLW ............................................................................ 213
ADDULNK ........................................................................ 250
ADDWF ............................................................................ 213
ADDWFC ......................................................................... 214
ADRESH Register ............................................................ 163
ADRESL Register  .................................................... 163, 166
Analog-to-Digital Converter. 
See
 A/D.
ANDLW ............................................................................ 214
ANDWF ............................................................................ 215
Assembler
MPASM Assembler .................................................. 204
B
BC .................................................................................... 215
BCF .................................................................................. 216
Block Diagrams
A/D ........................................................................... 166
Analog Input Model .................................................. 167
Comparator Analog Input Model  .............................. 175
Comparator Voltage Reference  ............................... 178
Dead-Time Control Unit for One 
PWM Output Pair  ............................................. 129
Device Clock  .............................................................. 20
EUSART Receive  .................................................... 153
EUSART Transmit ................................................... 151
External Power-on Reset Circuit 
(Slow VDD Power-up)  ........................................ 35
Fail-Safe Clock Monitor  ........................................... 197
Generic I/O Port ......................................................... 81
Interrupt Logic ............................................................ 88
Low-Voltage Detect  ................................................. 180
On-Chip Reset Circuit ................................................ 33
PIC18F1230/1330 ..................................................... 10
PLL (HS Mode) .......................................................... 17
Power Control PWM  ................................................ 112
PWM (One Output Pair, 
Complementary Mode)  .................................... 113
PWM (One Output Pair, Independent Mode)  .......... 113
PWM I/O Pin ............................................................ 136
PWM Time Base ...................................................... 115
Reads From Flash Program Memory  ........................ 69
Single Comparator ................................................... 174
Table Read Operation  ............................................... 65
Table Write Operation  ............................................... 66
Table Writes to Flash Program Memory .................... 71
Timer0 in 16-Bit Mode  ............................................. 102
Timer0 in 8-Bit Mode  ............................................... 102
Timer1 ..................................................................... 106
Timer1 (16-Bit Read/Write Mode) ............................ 106
Watchdog Timer  ...................................................... 194
BN .................................................................................... 216
BNC ................................................................................. 217
BNN ................................................................................. 217
BNOV .............................................................................. 218
BNZ ................................................................................. 218
BOR. 
See
 Brown-out Reset.
BOV ................................................................................. 221
BRA ................................................................................. 219
Brown-out Reset (BOR) ..................................................... 36
Detecting ................................................................... 36
Disabling in Sleep Mode ............................................ 36
Software Enabled  ...................................................... 36
BSF .................................................................................. 219
BTFSC ............................................................................. 220
BTFSS ............................................................................. 220
BTG ................................................................................. 221
BZ .................................................................................... 222
C
C Compilers
MPLAB C18 ............................................................. 204
MPLAB C30 ............................................................. 204
CALL ................................................................................ 222
CALLW ............................................................................ 251
Clock Sources .................................................................... 20
Selecting the 31 kHz Source  ..................................... 21
Selection Using OSCCON Register  .......................... 21
CLRF ............................................................................... 223
CLRWDT ......................................................................... 223
Code Examples
16 x 16 Signed Multiply Routine  ................................ 80
16 x 16 Unsigned Multiply Routine  ............................ 80
8 x 8 Signed Multiply Routine  .................................... 79
8 x 8 Unsigned Multiply Routine  ................................ 79
Computed GOTO Using an Offset Value  .................. 48
Data EEPROM Read ................................................. 77
Data EEPROM Refresh Routine  ............................... 78

PIC18F1230/1330
DS39758C-page 300 Advance Information © 2007 Microchip Technology Inc.
Data EEPROM Write  .................................................77
Erasing a Flash Program Memory Row  ..................... 70
Fast Register Stack .................................................... 48
How to Clear RAM (Bank 0) Using 
Indirect Addressing  ............................................ 59
Implementing a Real-Time Clock Using 
a Timer1 Interrupt Service  ...............................109
Initializing PORTA ...................................................... 81
Initializing PORTB ...................................................... 84
Reading a Flash Program Memory Word  .................. 69
Saving STATUS, WREG and BSR 
Registers in RAM  ............................................... 99
Writing to Flash Program Memory  ....................... 72–73
Code Protection  ....................................................... 183, 199
Associated Registers  ...............................................199
Configuration Register Protection  ............................202
Data EEPROM ......................................................... 202
Program Memory  ..................................................... 200
COMF ............................................................................... 224
Comparator ...................................................................... 173
Analog Input Connection 
Considerations .................................................175
Associated Registers  ...............................................176
Configuration ............................................................ 174
Effects of a Reset .....................................................175
Interrupts .................................................................. 174
Operation .................................................................174
Operation During Sleep  ........................................... 175
Outputs ....................................................................174
Reference ................................................................ 174
Response Time  ........................................................ 174
Comparator Specifications  ...............................................274
Comparator Voltage Reference  ....................................... 177
Accuracy and Error  .................................................. 178
Associated Registers  ...............................................178
Configuring ...............................................................177
Effects of a Reset .....................................................178
Operation During Sleep  ........................................... 178
Computed GOTO ............................................................... 48
Configuration Bits ............................................................. 183
Context Saving During Interrupts .......................................99
Conversion Considerations  .............................................. 296
CPFSEQ .......................................................................... 224
CPFSGT ...........................................................................225
CPFSLT ...........................................................................225
Crystal Oscillator/Ceramic Resonator  ................................ 15
Customer Change Notification Service  ............................ 306
Customer Notification Service .......................................... 306
Customer Support  ............................................................ 306
D
Data Addressing Modes ..................................................... 59
Comparing Options with the Extended 
Instruction Set Enabled ...................................... 62
Direct ..........................................................................59
Indexed Literal Offset  .................................................61
Instructions Affected  ..........................................61
Indirect .......................................................................59
Inherent and Literal  ....................................................59
Data EEPROM Memory ..................................................... 75
Associated Registers  ................................................. 78
EEADR Register ........................................................ 75
EECON1 and EECON2 Registers  ............................. 75
Operation During Code-Protect  ................................. 78
Protection Against Spurious Write  ............................. 77
Reading ..................................................................... 77
Using ......................................................................... 78
Write Verify  ................................................................ 77
Writing ....................................................................... 77
Data Memory  ..................................................................... 51
Access Bank  .............................................................. 53
and the Extended Instruction Set  .............................. 61
Bank Select Register (BSR)  ...................................... 51
General Purpose Registers  ....................................... 53
Map for PIC18F1230/1330  ........................................ 52
Special Function Registers  ........................................ 54
DAW ................................................................................ 226
DC and AC Characteristics
Graphs and Tables  .................................................. 287
DC Characteristics ........................................................... 271
Power-Down and Supply Current  ............................ 261
Supply Voltage  ........................................................ 260
DCFSNZ .......................................................................... 227
DECF ............................................................................... 226
DECFSZ .......................................................................... 227
Development Support  ...................................................... 203
Device Differences ........................................................... 295
Device Overview .................................................................. 7
Details on Individual Family Members ......................... 8
Features (table)  ........................................................... 9
New Core Features ...................................................... 7
Other Special Features ................................................ 8
Device Reset Timers  ......................................................... 37
Oscillator Start-up Timer (OST) ................................. 37
PLL Lock Time-out ..................................................... 37
Power-up Timer (PWRT)  ........................................... 37
Time-out Sequence  ................................................... 37
Direct Addressing  .............................................................. 60
E
Effect on Standard PIC MCU Instructions  ....................... 254
Effects of Power-Managed Modes on 
Various Clock Sources  .............................................. 23
Electrical Characteristics  ................................................. 257
Enhanced Universal Synchronous Asynchronous 
Receiver Transmitter (EUSART).
 See 
EUSART.
Equations
A/D Acquisition Time  ............................................... 168
A/D Minimum Charging Time ................................... 168
Calculating the Minimum Required 
Acquisition Time  .............................................. 168
PWM Frequency  ...................................................... 123
PWM Period for Continuous Up/Down 
Count Mode  ..................................................... 123
PWM Period for Free-Running Mode  ...................... 123
PWM Resolution  ...................................................... 123
Errata ................................................................................... 5

© 2007 Microchip Technology Inc. Advance Information DS39758C-page 301
PIC18F1230/1330
EUSART
Asynchronous Mode  ................................................ 151
12-Bit Break Character Sequence  ................... 156
Associated Registers, Receive  ........................ 154
Associated Registers, Transmit  ....................... 152
Auto-Wake-up on Sync Break Character ......... 154
Receiver ........................................................... 153
Receiving a Break Character ........................... 156
Setting Up 9-Bit Mode with 
Address Detect  ........................................ 153
Transmitter ....................................................... 151
Baud Rate Generator
Operation in Power-Managed Modes  .............. 145
Baud Rate Generator (BRG) .................................... 145
Associated Registers  ....................................... 146
Auto-Baud Rate Detect .................................... 149
Baud Rate Error, Calculating  ........................... 146
Baud Rates, Asynchronous Modes  ................. 147
High Baud Rate Select (BRGH Bit)  ................. 145
Sampling .......................................................... 145
Synchronous Master Mode  ...................................... 157
Associated Registers, Receive  ........................ 159
Associated Registers, Transmit  ....................... 158
Reception ......................................................... 159
Transmission ................................................... 157
Synchronous Slave Mode  ........................................ 160
Associated Registers, Receive  ........................ 161
Associated Registers, Transmit  ....................... 160
Reception ......................................................... 161
Transmission ................................................... 160
Extended Instruction Set
ADDFSR .................................................................. 250
ADDULNK ................................................................ 250
and Using MPLAB Tools .......................................... 256
CALLW ..................................................................... 251
Considerations for Use  ............................................ 254
MOVSF .................................................................... 251
MOVSS .................................................................... 252
PUSHL ..................................................................... 252
SUBFSR .................................................................. 253
SUBULNK ................................................................ 253
Syntax ...................................................................... 249
External Clock Input ........................................................... 16
F
Fail-Safe Clock Monitor ............................................ 183, 197
Exiting Operation  ..................................................... 197
Interrupts in Power-Managed Modes ....................... 198
POR or Wake From Sleep  ....................................... 198
WDT During Oscillator Failure  ................................. 197
Fast Register Stack ............................................................ 48
Firmware Instructions ....................................................... 207
Flash Program Memory  ..................................................... 65
Associated Registers  ................................................. 73
Control Registers  ....................................................... 66
EECON1 and EECON2  ..................................... 66
TABLAT (Table Latch) Register ......................... 68
TBLPTR (Table Pointer) Register ...................... 68
Erase Sequence  ........................................................ 70
Erasing ....................................................................... 70
Operation During Code-Protect  ................................. 73
Reading ...................................................................... 69
Table Pointer
Boundaries Based on Operation ........................ 68
Operations with TBLRD and TBLWT (table) ...... 68
Table Pointer Boundaries  .......................................... 68
Table Reads and Table Writes  .................................. 65
Write Sequence  ......................................................... 71
Writing ....................................................................... 71
Protection Against Spurious Writes  ................... 73
Unexpected Termination  ................................... 73
Write Verify ........................................................ 73
FSCM. 
See
 Fail-Safe Clock Monitor.
G
GOTO .............................................................................. 228
H
Hardware Multiplier ............................................................ 79
Introduction ................................................................ 79
Operation ................................................................... 79
Performance Comparison .......................................... 79
I
I/O Ports  ............................................................................ 81
ID Locations ............................................................. 183, 202
INCF ................................................................................ 228
INCFSZ ............................................................................ 229
In-Circuit Debugger .......................................................... 202
In-Circuit Serial Programming (ICSP) ...................... 183, 202
Independent PWM Mode
Duty Cycle Assignment  ........................................... 131
Output ...................................................................... 131
Output, Channel Override ........................................ 132
Indexed Literal Offset Addressing
and Standard PIC18 Instructions ............................. 254
Indexed Literal Offset Mode ............................................. 254
Indirect Addressing ............................................................ 60
INFSNZ ............................................................................ 229
Initialization Conditions for all Registers  ...................... 41–44
Instruction Cycle  ................................................................ 49
Clocking Scheme ....................................................... 49
Flow/Pipelining .......................................................... 49
Instruction Set .................................................................. 207
ADDLW .................................................................... 213
ADDWF ................................................................... 213
ADDWF (Indexed Literal Offset Mode) .................... 255
ADDWFC ................................................................. 214
ANDLW .................................................................... 214
ANDWF ................................................................... 215
BC ............................................................................ 215
BCF ......................................................................... 216
BN ............................................................................ 216
BNC ......................................................................... 217
BNN ......................................................................... 217
BNOV ...................................................................... 218
BNZ ......................................................................... 218
BOV ......................................................................... 221
BRA ......................................................................... 219
BSF .......................................................................... 219
BSF (Indexed Literal Offset Mode)  .......................... 255
BTFSC ..................................................................... 220
BTFSS ..................................................................... 220
BTG ......................................................................... 221
BZ ............................................................................ 222
CALL ........................................................................ 222
CLRF ....................................................................... 223
CLRWDT ................................................................. 223
COMF ...................................................................... 224
CPFSEQ .................................................................. 224
CPFSGT .................................................................. 225
CPFSLT ................................................................... 225

PIC18F1230/1330
DS39758C-page 302 Advance Information © 2007 Microchip Technology Inc.
DAW ......................................................................... 226
DCFSNZ .................................................................. 227
DECF .......................................................................226
DECFSZ ................................................................... 227
Extended Instruction Set .......................................... 249
General Format  ........................................................ 209
GOTO ......................................................................228
INCF ......................................................................... 228
INCFSZ ....................................................................229
INFSNZ ....................................................................229
IORLW .....................................................................230
IORWF .....................................................................230
LFSR ........................................................................ 231
MOVF ....................................................................... 231
MOVFF ....................................................................232
MOVLB ....................................................................232
MOVLW ................................................................... 233
MOVWF ................................................................... 233
MULLW ....................................................................234
MULWF ....................................................................234
NEGF .......................................................................235
NOP ......................................................................... 235
Opcode Field Descriptions ....................................... 208
POP ......................................................................... 236
PUSH ....................................................................... 236
RCALL ..................................................................... 237
RESET .....................................................................237
RETFIE ....................................................................238
RETLW .................................................................... 238
RETURN .................................................................. 239
RLCF ........................................................................239
RLNCF ..................................................................... 240
RRCF ....................................................................... 240
RRNCF .................................................................... 241
SETF ........................................................................ 241
SETF (Indexed Literal Offset Mode)  ........................ 255
SLEEP ..................................................................... 242
Standard Instructions  ............................................... 207
SUBFWB ..................................................................242
SUBLW ....................................................................243
SUBWF ....................................................................243
SUBWFB ..................................................................244
SWAPF ....................................................................244
TBLRD ..................................................................... 245
TBLWT .....................................................................246
TSTFSZ ................................................................... 247
XORLW .................................................................... 247
XORWF .................................................................... 248
INTCON Registers  ....................................................... 89–91
Internal Oscillator Block  .....................................................18
Adjustment .................................................................18
INTIO Modes .............................................................. 18
INTOSC Frequency Drift  ............................................ 18
INTOSC Output Frequency ........................................ 18
OSCTUNE Register  ...................................................18
PLL in INTOSC Modes  ..............................................18
Internal RC Oscillator
Use with WDT  .......................................................... 194
Internet Address ............................................................... 306
Interrupt Sources .............................................................. 183
A/D Conversion Complete  ....................................... 167
INTx Pin  ..................................................................... 99
PORTB, Interrupt-on-Change  .................................... 99
TMR0 ......................................................................... 99
TMR1 Overflow  ........................................................105
Interrupts ............................................................................ 87
Interrupts, Flag Bits
Interrupt-on-Change Flag (RBIF Bit) .......................... 84
INTOSC, INTRC. 
See 
Internal Oscillator Block.
IORLW ............................................................................. 230
IORWF ............................................................................. 230
IPR Registers ..................................................................... 96
L
LFSR ................................................................................ 231
Low-Voltage Detect  ......................................................... 179
Applications ............................................................. 182
Associated Registers  ............................................... 182
Characteristics ......................................................... 275
Current Consumption ............................................... 181
Effects of a Reset  .................................................... 182
Operation ................................................................. 180
During Sleep .................................................... 182
Setup ....................................................................... 181
Start-up Time  ........................................................... 181
Typical Application ................................................... 182
Low-Voltage ICSP Programming. 
See
 Single-Supply 
ICSP Programming
LVD. 
See
 Low-Voltage Detect.  ........................................ 179
M
Master Clear (MCLR) ......................................................... 35
Memory Organization  ........................................................ 45
Data Memory  ............................................................. 51
Program Memory ....................................................... 45
Memory Programming Requirements .............................. 273
Microchip Internet Web Site ............................................. 306
Migration from Baseline to 
Enhanced Devices ................................................... 296
Migration from High-End to 
Enhanced Devices ................................................... 297
Migration from Mid-Range to 
Enhanced Devices ................................................... 297
MOVF .............................................................................. 231
MOVFF ............................................................................ 232
MOVLB ............................................................................ 232
MOVLW ........................................................................... 233
MOVSF ............................................................................ 251
MOVSS ............................................................................ 252
MOVWF ........................................................................... 233
MPLAB ASM30 Assembler, Linker, Librarian  .................. 204
MPLAB ICD 2 In-Circuit Debugger  .................................. 205
MPLAB ICE 2000 High-Performance 
Universal In-Circuit Emulator  ................................... 205
MPLAB Integrated Development 
Environment Software  ............................................. 203
MPLAB PM3 Device Programmer  ................................... 205
MPLAB REAL ICE In-Circuit 
Emulator System  ..................................................... 205
MPLINK Object Linker/MPLIB 
Object Librarian  ....................................................... 204
MULLW ............................................................................ 234
MULWF ............................................................................ 234
N
NEGF ............................................................................... 235
NOP ................................................................................. 235

 2007 Microchip Technology Inc. Advance Information DS39758C-page 303
PIC18F1230/1330
O
Oscillator Configuration ...................................................... 15
EC .............................................................................. 15
ECIO .......................................................................... 15
HS .............................................................................. 15
HSPLL ........................................................................ 15
Internal Oscillator Block  ............................................. 18
INTIO1 ....................................................................... 15
INTIO2 ....................................................................... 15
LP ............................................................................... 15
RC .............................................................................. 15
RCIO .......................................................................... 15
XT .............................................................................. 15
Oscillator Selection  .......................................................... 183
Oscillator Start-up Timer (OST)  ................................... 23, 37
Oscillator Switching ............................................................ 20
Oscillator Transitions  ......................................................... 21
Oscillator, Timer1  ............................................................. 105
P
Packaging ........................................................................ 289
Details ...................................................................... 290
Marking Information  ................................................. 289
PICSTART Plus Development 
Programmer ............................................................. 206
PIE Registers  ..................................................................... 94
Pin Functions
AVDD .......................................................................... 14
AVSS .......................................................................... 14
MCLR/VPP/RA5/FLTA ................................................ 11
NC .............................................................................. 14
RA0/AN0/INT0/KBI0/CMP0 ....................................... 12
RA1/AN1/INT1/KBI1 .................................................. 12
RA2/TX/CK ................................................................ 12
RA3/RX/DT ................................................................ 12
RA4/T0CKI/AN2//VREF+ ............................................. 12
RA6/OSC2/CLKO/T1OSO/T1CKI/AN3 ...................... 11
RA7/OSC1/CLKI/T1OSI/FLTA ................................... 11
RB0/PWM0 ................................................................ 13
RB1/PWM1 ................................................................ 13
RB2/INT2/KBI2/CMP2/T1OSO/T1CKI ....................... 13
RB3/INT3/KBI3/CMP1/T1OSI .................................... 13
RB4/PWM2 ................................................................ 13
RB5/PWM3 ................................................................ 13
RB6/PWM4/PGC ....................................................... 13
RB7/PWM5/PGD ....................................................... 13
VDD ............................................................................ 14
VSS ............................................................................. 14
Pinout I/O Descriptions
PIC18F1230/1330 ...................................................... 11
PIR Registers ..................................................................... 92
PLL Frequency Multiplier  ................................................... 17
HSPLL Oscillator Mode .............................................. 17
Use with INTOSC ....................................................... 17
POP ................................................................................. 236
POR. 
See
 Power-on Reset.
PORTA
Associated Registers  ................................................. 83
LATA Register ............................................................ 81
PORTA Register  ........................................................ 81
TRISA Register .......................................................... 81
PORTB
Associated Registers ................................................. 86
Interrupt-on-Change Flag (RBIF Bit)  ......................... 84
LATB Register  ........................................................... 84
PORTB Register ........................................................ 84
TRISB Register .......................................................... 84
Power Control PWM  ........................................................ 111
Associated Registers ............................................... 139
Control Registers ..................................................... 114
Functionality ............................................................ 114
Power-Managed Modes ..................................................... 25
and A/D Operation ................................................... 170
Clock Sources  ........................................................... 25
Clock Transitions and Status Indicators  .................... 26
Effects on Clock Sources  .......................................... 23
Entering ..................................................................... 25
Exiting Idle and Sleep Modes  .................................... 31
By Interrupt ........................................................ 31
By Reset ............................................................ 31
By WDT Time-out  .............................................. 31
Without an Oscillator Start-up Delay  ................. 32
Idle Modes  ................................................................. 29
PRI_IDLE .......................................................... 30
RC_IDLE ........................................................... 31
SEC_IDLE ......................................................... 30
Multiple Sleep Commands ......................................... 26
Run Modes  ................................................................ 26
PRI_RUN ........................................................... 26
RC_RUN ............................................................ 27
SEC_RUN ......................................................... 26
Selecting .................................................................... 25
Sleep Mode  ............................................................... 29
Summary (table)  ........................................................ 25
Power-on Reset (POR) ...................................................... 35
Time-out Sequence  ................................................... 37
Power-up Delays  ............................................................... 23
Power-up Timer (PWRT)  ................................................... 23
Prescaler, Timer0  ............................................................ 103
PRI_IDLE Mode ................................................................. 30
PRI_RUN Mode ................................................................. 26
Program Counter  ............................................................... 46
PCL, PCH and PCU Registers  .................................. 46
PCLATH and PCLATU Registers  .............................. 46
Program Memory
and Extended Instruction Set  .................................... 63
Instructions ................................................................ 50
Two-Word .......................................................... 50
Interrupt Vector .......................................................... 45
Look-up Tables .......................................................... 48
Map and Stack (diagram)  .......................................... 45
Reset Vector .............................................................. 45
Program Verification  ........................................................ 199
Programming, Device Instructions ................................... 207
PUSH ............................................................................... 236
PUSH and POP Instructions .............................................. 47
PUSHL ............................................................................. 252
PWM
Fault Input ................................................................ 136
Output and Polarity Control  ..................................... 135
Single-Pulse Operation ............................................ 132
Special Event Trigger  .............................................. 138
Update Lockout  ....................................................... 138

PIC18F1230/1330
DS39758C-page 304 Advance Information © 2007 Microchip Technology Inc.
PWM Dead-Time
Decrementing the Counter .......................................130
Distortion ..................................................................131
Generators ............................................................... 129
Insertion ................................................................... 129
Ranges ..................................................................... 130
PWM Duty Cycle  .............................................................. 125
Center-Aligned ......................................................... 127
Complementary Operation .......................................128
Edge-Aligned ........................................................... 126
Register Buffers  ....................................................... 126
Registers .................................................................. 125
PWM Output Override ...................................................... 132
Complementary Mode .............................................. 132
Examples .................................................................134
Synchronization .......................................................132
PWM Period  ..................................................................... 123
PWM Time Base  ..............................................................114
Continuous Up/Down Count Modes ......................... 119
Free-Running Mode  ................................................. 119
Interrupts .................................................................. 119
In Continuous Up/Down Count Mode  .............. 120
In Double Update Mode ................................... 122
In Free-Running Mode  ..................................... 119
In Single-Shot Mode  ........................................ 120
Postscaler ................................................................119
Prescaler ..................................................................119
Single-Shot Mode  .................................................... 119
R
RAM. 
See
 Data Memory.
RBIF Bit .............................................................................. 84
RC Oscillator  ......................................................................17
RCIO Oscillator Mode  ................................................ 17
RC_IDLE Mode  .................................................................. 31
RC_RUN Mode  .................................................................. 27
RCALL .............................................................................. 237
RCON Register
Bit Status During Initialization  .................................... 40
Reader Response  ............................................................ 307
Register File Summary ................................................. 55–57
Registers
ADCON0 (A/D Control 0)  ......................................... 163
ADCON1 (A/D Control 1)  ......................................... 164
ADCON2 (A/D Control 2)  ......................................... 165
BAUDCON (Baud Rate Control)  .............................. 144
CMCON (Comparator Control)  ................................ 173
CONFIG1H (Configuration 1 High)  ..........................184
CONFIG2H (Configuration 2 High)  ..........................186
CONFIG2L (Configuration 2 Low) ............................ 185
CONFIG3H (Configuration 3 High)  ..........................188
CONFIG3L (Configuration 3 Low) ............................ 187
CONFIG4L (Configuration 4 Low) ............................ 189
CONFIG5H (Configuration 5 High)  ..........................190
CONFIG5L (Configuration 5 Low) ............................ 190
CONFIG6H (Configuration 6 High)  ..........................191
CONFIG6L (Configuration 6 Low) ............................ 191
CONFIG7H (Configuration 7 High)  ..........................192
CONFIG7L (Configuration 7 Low) ............................ 192
CVRCON (Comparator Voltage 
Reference Control) ........................................... 177
DEVID1 (Device ID 1)  .............................................. 193
DEVID2 (Device ID 2)  .............................................. 193
DTCON (Dead-Time Control)  .................................. 130
EECON1 (EEPROM Control 1) ............................ 67, 76
FLTCONFIG (Fault Configuration) ........................... 137
INTCON (Interrupt Control) ........................................ 89
INTCON2 (Interrupt Control 2) ................................... 90
INTCON3 (Interrupt Control 3) ................................... 91
IPR1 (Peripheral Interrupt Priority 1)  ......................... 96
IPR2 (Peripheral Interrupt Priority 2)  ......................... 97
IPR3 (Peripheral Interrupt Priority 3)  ......................... 97
LVDCON (Low-Voltage Detect Control)  .................. 179
OSCCON (Oscillator Control) .................................... 22
OSCTUNE (Oscillator Tuning) ................................... 19
OVDCOND (Output Override Control) ..................... 134
OVDCONS (Output State) ....................................... 134
PIE1 (Peripheral Interrupt Enable 1) .......................... 94
PIE2 (Peripheral Interrupt Enable 2) .......................... 95
PIE3 (Peripheral Interrupt Enable 3) .......................... 95
PIR1 (Peripheral Interrupt Request (Flag) 1) ............. 92
PIR2 (Peripheral Interrupt Request (Flag) 2) ............. 93
PIR3 (Peripheral Interrupt Request (Flag) 3) ............. 93
PTCON0 (PWM Timer Control 0)  ............................ 116
PTCON1 (PWM Timer Control 1)  ............................ 116
PWMCON0 (PWM Control 0)  .................................. 117
PWMCON1 (PWM Control 1)  .................................. 118
RCON (Reset Control) ......................................... 34, 98
RCSTA (Receive Status and Control)  ..................... 143
STATUS .................................................................... 58
STKPTR (Stack Pointer) ............................................ 47
T0CON (Timer0 Control)  ......................................... 101
T1CON (Timer1 Control)  ......................................... 105
TXSTA (Transmit Status and Control) ..................... 142
WDTCON (Watchdog Timer Control)  ...................... 195
RESET ............................................................................. 237
Reset State of Registers .................................................... 40
Resets ........................................................................ 33, 183
Brown-out Reset (BOR) ........................................... 183
Oscillator Start-up Timer (OST) ............................... 183
Power-on Reset (POR) ............................................ 183
Power-up Timer (PWRT)  ......................................... 183
RETFIE ............................................................................ 238
RETLW ............................................................................ 238
RETURN .......................................................................... 239
Return Address Stack ........................................................ 46
Associated Registers  ................................................. 46
Return Stack Pointer (STKPTR)  ........................................ 47
Revision History ............................................................... 295
RLCF ............................................................................... 239
RLNCF ............................................................................. 240
RRCF ............................................................................... 240
RRNCF ............................................................................ 241
S
SEC_IDLE Mode  ............................................................... 30
SEC_RUN Mode ................................................................ 26
SETF ................................................................................ 241
Single-Supply ICSP Programming ................................... 202
Single-Supply ICSP Programming.
SLEEP ............................................................................. 242
Sleep
OSC1 and OSC2 Pin States ...................................... 23
Software Simulator (MPLAB SIM)  ................................... 204
Special Features of the CPU  ........................................... 183
Special Function Registers
Map ............................................................................ 54
Stack Full/Underflow Resets .............................................. 48
SUBFSR .......................................................................... 253
SUBFWB ......................................................................... 242
SUBLW ............................................................................ 243
SUBULNK ........................................................................ 253

© 2007 Microchip Technology Inc. Advance Information DS39758C-page 305
PIC18F1230/1330
SUBWF ............................................................................ 243
SUBWFB .......................................................................... 244
SWAPF ............................................................................ 244
T
Table Reads/Table Writes  ................................................. 48
TBLRD ............................................................................. 245
TBLWT ............................................................................. 246
Time-out in Various Situations (table)  ................................ 37
Timer0 .............................................................................. 101
16-Bit Mode Timer Reads and Writes ...................... 103
Associated Registers  ............................................... 103
Clock Source Edge Select (T0SE Bit) ...................... 103
Clock Source Select (T0CS Bit) ............................... 103
Interrupt .................................................................... 103
Operation ................................................................. 103
Prescaler .................................................................. 103
Switching the Assignment ................................ 103
Prescaler Assignment (PSA Bit)  .............................. 103
Prescaler Select (T0PS2:T0PS0 Bits)  ..................... 103
Prescaler. 
See
 Prescaler, Timer0.
Timer1 .............................................................................. 105
16-Bit Read/Write Mode ........................................... 108
Associated Registers  ............................................... 109
Interrupt .................................................................... 108
Operation ................................................................. 106
Oscillator .......................................................... 105, 107
Oscillator Layout Considerations  ............................. 107
Overflow Interrupt  .................................................... 105
TMR1H Register  ...................................................... 105
TMR1L Register ....................................................... 105
Use as a Clock Source  ............................................ 107
Use as a Real-Time Clock  ....................................... 108
Timing Diagrams
A/D Conversion ........................................................ 285
Asynchronous Reception  ......................................... 154
Asynchronous Transmission .................................... 152
Asynchronous Transmission 
(Back-to-Back) ................................................. 152
Automatic Baud Rate Calculation  ............................ 150
Auto-Wake-up Bit (WUE) During 
Normal Operation  ............................................ 155
Auto-Wake-up Bit (WUE) During Sleep  ................... 155
BRG Overflow Sequence ......................................... 150
Brown-out Reset (BOR)  ........................................... 281
CLKO and I/O  .......................................................... 280
Clock/Instruction Cycle  .............................................. 49
Dead-Time Insertion for 
Complementary PWM ...................................... 129
Duty Cycle Update Times in Continuous 
Up/Down Count Mode  ..................................... 126
Duty Cycle Update Times in Continuous 
Up/Down Count Mode with Double Updates  ... 127
Edge-Aligned PWM .................................................. 126
EUSART Synchronous Receive 
(Master/Slave) ................................................. 283
EUSART Synchronous Transmission 
(Master/Slave) ................................................. 283
External Clock (All Modes Except PLL)  ................... 278
Fail-Safe Clock Monitor ............................................ 198
Low-Voltage Detect Characteristics ......................... 275
Low-Voltage Detect Operation ................................. 181
Override Bits in Complementary Mode  .................... 133
PWM Output Override Example #1 .......................... 135
PWM Output Override Example #2 .......................... 135
PWM Period Buffer Updates in Continuous 
Up/Down Count Modes  ................................... 124
PWM Period Buffer Updates in 
Free-Running Mode ......................................... 124
PWM Time Base Interrupt 
(Free-Running Mode)  ...................................... 120
PWM Time Base Interrupt (Single-Shot Mode)  ....... 121
PWM Time Base Interrupts (Continuous 
Up/Down Count Mode with Double Updates) .. 122
PWM Time Base Interrupts (Continuous 
Up/Down Count Mode)  .................................... 121
Reset, Watchdog Timer (WDT), Oscillator Start-up 
Timer (OST), Power-up Timer (PWRT)  ........... 281
Send Break Character Sequence ............................ 156
Slow Rise Time (MCLR Tied to VDD, 
VDD Rise > TPWRT) ............................................ 39
Start of Center-Aligned PWM  .................................. 127
Synchronous Reception 
(Master Mode, SREN)  ..................................... 159
Synchronous Transmission  ..................................... 157
Synchronous Transmission (Through TXEN) .......... 158
Time-out Sequence on POR w/PLL Enabled 
(MCLR Tied to VDD) .......................................... 39
Time-out Sequence on Power-up 
(MCLR Not Tied to VDD, Case 1)  ...................... 38
Time-out Sequence on Power-up 
(MCLR Not Tied to VDD, Case 2)  ...................... 38
Time-out Sequence on Power-up 
(MCLR Tied to VDD, VDD Rise < TPWRT) ........... 38
Timer0 and Timer1 External Clock  .......................... 282
Transition for Entry to Idle Mode  ............................... 30
Transition for Entry to SEC_RUN Mode  .................... 27
Transition for Entry to Sleep Mode  ............................ 29
Transition for Two-Speed Start-up 
(INTOSC to HSPLL)  ........................................ 196
Transition for Wake From Idle to Run Mode .............. 30
Transition for Wake From Sleep (HSPLL)  ................. 29
Transition from RC_RUN Mode to 
PRI_RUN Mode ................................................. 28
Transition from SEC_RUN Mode to 
PRI_RUN Mode (HSPLL) .................................. 27
Transition to RC_RUN Mode ..................................... 28
Timing Diagrams and Specifications  ............................... 278
CLKO and I/O Requirements ................................... 280
EUSART Synchronous Receive 
Requirements .................................................. 283
EUSART Synchronous Transmission 
Requirements .................................................. 283
External Clock Requirements  .................................. 278
PLL Clock  ................................................................ 279
Reset, Watchdog Timer, Oscillator Start-up 
Timer, Power-up Timer and Brown-out 
Reset Requirements ........................................ 281
Timer0 and Timer1 External Clock 
Requirements .................................................. 282
Top-of-Stack Access .......................................................... 46
TSTFSZ ........................................................................... 247
Two-Speed Start-up ................................................. 183, 196
Two-Word Instructions
Example Cases  ......................................................... 50
TXSTA Register
BRGH Bit ................................................................. 145

PIC18F1230/1330
DS39758C-page 306 Advance Information © 2007 Microchip Technology Inc.
V
Voltage Reference Specifications  .................................... 274
W
Watchdog Timer (WDT)  ........................................... 183, 194
Associated Registers  ...............................................195
Control Register  ....................................................... 194
During Oscillator Failure  ..........................................197
Programming Considerations  ..................................194
WWW Address .................................................................306
WWW, On-Line Support ....................................................... 5
X
XORLW ............................................................................ 247
XORWF ............................................................................ 248

PIC18F1230/1330

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

software

•General Technical Support – Frequently Asked

Questions (FAQ), technical support requests,

online discussion groups, Microchip consultant

program member listing

•Business of Microchip – Product selector and

ordering guides, latest Microchip press releases,

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

www.microchip.com, click on Customer Change

Notification and follow the registration instructions.

CUSTOMER SUPPORT

Users of Microchip products can receive assistance

through several channels:

• Distributor or Representative

• Local Sales Office

• Field Application Engineer (FAE)

• Technical Support

• Development Systems Information Line

Customers should contact their distributor,

representative or field application engineer (FAE) for

support. Local sales offices are also available to help

customers. A listing of sales offices and locations is

included in the back of this document.

Technical support is available through the web site

at: http://support.microchip.com

PIC18F1230/1330

READER RESPONSE

It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip prod-

uct. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation

can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150.

Please list the following information, and use this outline to provide us with your comments about this document.

To: Technical Publications Manager

RE: Reader Response

Total Pages Sent ________

From: Name

Company

Address

City / State / ZIP / Country

Telephone: (_______) _________ - _________

Application (optional):

Would you like a reply? Y N

Device: Literature Number:

Questions:

FAX: (______) _________ - _________

DS39758CPIC18F1230/1330

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?

PIC18F1230/1330

PIC18F1230/1330 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 PIC18F1230/1330(1)

PIC18F1230/1330T(2)

VDD range 4.2V to 5.5V

PIC18LF1230/1330(1)

PIC18LF1230/1330T(2)

VDD range 2.0V to 5.5V

Temperature Range I = -40°C to +85°C (Industrial)

E= -40°C to +125°C (Extended)

Package(3) SO = Plastic Small Outline (SOIC)

SS = Plastic Shrink Small Outline (SSOP)

P = Plastic Dual In-line (PDIP)

ML = Plastic Quad Flat No Lead (QFN)

Pattern QTP, SQTP, Code or Special Requirements

(blank otherwise)

Examples:

a) PIC18LF1330-I/P 301 = Industrial temp.,

PDIP package, Extended VDD limits,

QTP pattern #301.

b) PIC18LF1230-I/SO = Industrial temp., SOIC

package, Extended VDD limits.

Note 1: F = Standard Voltage Range

LF = Wide Voltage Range

2: T = in tape and reel QFN packages only

AMERICAS

Corporate Office

2355 West Chandler Blvd.

Chandler, AZ 85224-6199

Tel: 480-792-7200

Fax: 480-792-7277

Technical Support:

http://support.microchip.com

Web Address:

www.microchip.com

Atlanta

Duluth, GA

Tel: 678-957-9614

Fax: 678-957-1455

Boston

Westborough, MA

Tel: 774-760-0087

Fax: 774-760-0088

Chicago

Itasca, IL

Tel: 630-285-0071

Fax: 630-285-0075

Dallas

Addison, TX

Tel: 972-818-7423

Fax: 972-818-2924

Detroit

Farmington Hills, MI

Tel: 248-538-2250

Fax: 248-538-2260

Kokomo

Kokomo, IN

Tel: 765-864-8360

Fax: 765-864-8387

Los Angeles

Mission Viejo, CA

Tel: 949-462-9523

Fax: 949-462-9608

Santa Clara

Santa Clara, CA

Tel: 408-961-6444

Fax: 408-961-6445

Toronto

Mississauga, Ontario,

Canada

Tel: 905-673-0699

Fax: 905-673-6509

ASIA/PACIFIC

Asia Pacific Office

Suites 3707-14, 37th Floor

Tower 6, The Gateway

Habour City, Kowloon

Hong Kong

Tel: 852-2401-1200

Fax: 852-2401-3431

Australia - Sydney

Tel: 61-2-9868-6733

Fax: 61-2-9868-6755

China - Beijing

Tel: 86-10-8528-2100

Fax: 86-10-8528-2104

China - Chengdu

Tel: 86-28-8665-5511

Fax: 86-28-8665-7889

China - Fuzhou

Tel: 86-591-8750-3506

Fax: 86-591-8750-3521

China - Hong Kong SAR

Tel: 852-2401-1200

Fax: 852-2401-3431

China - Qingdao

Tel: 86-532-8502-7355

Fax: 86-532-8502-7205

China - Shanghai

Tel: 86-21-5407-5533

Fax: 86-21-5407-5066

China - Shenyang

Tel: 86-24-2334-2829

Fax: 86-24-2334-2393

China - Shenzhen

Tel: 86-755-8203-2660

Fax: 86-755-8203-1760

China - Shunde

Tel: 86-757-2839-5507

Fax: 86-757-2839-5571

China - Wuhan

Tel: 86-27-5980-5300

Fax: 86-27-5980-5118

China - Xian

Tel: 86-29-8833-7250

Fax: 86-29-8833-7256

ASIA/PACIFIC

India - Bangalore

Tel: 91-80-4182-8400

Fax: 91-80-4182-8422

India - New Delhi

Tel: 91-11-4160-8631

Fax: 91-11-4160-8632

India - Pune

Tel: 91-20-2566-1512

Fax: 91-20-2566-1513

Japan - Yokohama

Tel: 81-45-471- 6166

Fax: 81-45-471-6122

Korea - Gumi

Tel: 82-54-473-4301

Fax: 82-54-473-4302

Korea - Seoul

Tel: 82-2-554-7200

Fax: 82-2-558-5932 or

82-2-558-5934

Malaysia - Penang

Tel: 60-4-646-8870

Fax: 60-4-646-5086

Philippines - Manila

Tel: 63-2-634-9065

Fax: 63-2-634-9069

Singapore

Tel: 65-6334-8870

Fax: 65-6334-8850

Taiwan - Hsin Chu

Tel: 886-3-572-9526

Fax: 886-3-572-6459

Taiwan - Kaohsiung

Tel: 886-7-536-4818

Fax: 886-7-536-4803

Taiwan - Taipei

Tel: 886-2-2500-6610

Fax: 886-2-2508-0102

Thailand - Bangkok

Tel: 66-2-694-1351

Fax: 66-2-694-1350

EUROPE

Austria - Wels

Tel: 43-7242-2244-39

Fax: 43-7242-2244-393

Denmark - Copenhagen

Tel: 45-4450-2828

Fax: 45-4485-2829

France - Paris

Tel: 33-1-69-53-63-20

Fax: 33-1-69-30-90-79

Germany - Munich

Tel: 49-89-627-144-0

Fax: 49-89-627-144-44

Italy - Milan

Tel: 39-0331-742611

Fax: 39-0331-466781

Netherlands - Drunen

Tel: 31-416-690399

Fax: 31-416-690340

Spain - Madrid

Tel: 34-91-708-08-90

Fax: 34-91-708-08-91

UK - Wokingham

Tel: 44-118-921-5869

Fax: 44-118-921-5820

WORLDWIDE SALES AND SERVICE

12/08/06