PIC18(L)F1XK22
20-Pin Flash Microcontrollers with XLP Technology
High-Performance RISC CPU
Analog Features
• C Compiler Optimized Architecture:
- Optional extended instruction set designed to
optimize re-entrant code
• 256 bytes Data EEPROM
• Up to 16 Kbytes Linear Program Memory
Addressing
• Up to 512 bytes Linear Data Memory Addressing
• Up to 16 MIPS Operation
• 16-bit Wide Instructions, 8-bit Wide Data Path
• Priority Levels for Interrupts
• 31-Level, Software Accessible Hardware Stack
• 8 x 8 Single-Cycle Hardware Multiplier
• Analog-to-Digital Converter (ADC) module
- 10-bit resolution, 12 channels
- Auto-acquisition capability
- Conversion available during Sleep
• Analog Comparator module:
- Two rail-to-rail analog comparators
- Independent input multiplexing
- Inputs and outputs externally accessible
• Voltage Reference module:
- Fixed Voltage Reference (FVR) with 1.024V,
2.048V and 4.096V output levels
- 5-bit rail-to-rail resistive Digital-to-Analog
Converter (DAC) with positive and negative
reference selection
Flexible Oscillator Structure
• Precision 16 MHz Internal Oscillator Block:
- Factory calibrated to ± 1%
- Software selectable frequencies range of
31 kHz to 16 MHz
- 64 MHz performance available using PLL –
no external components required
• Four Crystal modes up to 64 MHz
• Two External Clock modes up to 64 MHz
• 4X Phase Lock Loop (PLL)
• Secondary Oscillator using Timer1 @ 32 kHz
• Fail-Safe Clock Monitor
- Allows for safe shutdown if peripheral clock
stops
• Two-Speed Oscillator Start-up
Special Microcontroller Features
•
•
•
•
•
•
•
•
•
2.3V - 5.5V Operation – PIC18F1XK22
1.8V-3.6V Operation – PIC18LF1XK22
Self-reprogrammable under Software Control
Power-on Reset (POR), Power-up Timer (PWRT)
and Oscillator Start-up Timer (OST)
Programmable Brown-out Reset (BOR)
Extended Watchdog Timer (WDT):
- Programmable period from 4 ms to 131s
Programmable Code Protection
In-Circuit Serial Programming™ (ICSP™) via
two pins
In-Circuit Debug via Two Pins
Extreme Low-Power Management
PIC18LF1XK22 with XLP Technology
• Sleep mode: 34 nA
• Watchdog Timer: 460 nA
• Timer1 Oscillator: 650 nA @ 32 kHz
2009-2016 Microchip Technology Inc.
Peripheral Highlights
• 17 I/O Pins and 1 Input-only Pin:
- High current sink/source 25 mA/25 mA
- Programmable weak pull-ups
- Programmable interrupt-on- change
- Three external interrupt pins
• Four Timer modules:
- Three 16-bit timers/counters with prescaler
- One 8-bit timer/counter with 8-bit period
register, prescaler and postscaler
- Dedicated, low-power Timer1 oscillator
• Enhanced Capture/Compare/PWM (ECCP)
module:
- One, two or four PWM outputs
- Selectable polarity
- Programmable dead time
- Auto-shutdown and Auto-restart
- PWM output steering control
• Master Synchronous Serial Port (MSSP) module
- 3-wire SPI (supports all four SPI modes)
- I2C Master and Slave modes (Slave mode
address masking)
• Enhanced Universal Synchronous Asynchronous
Receiver Transmitter module (EUSART)
- Supports RS-232, RS-485 and LIN 2.0
- Auto-Baud Detect
- Auto Wake-up on Break
• SR Latch (555 Timer) module with:
- Configurable inputs and outputs
- Supports mTouch® capacitive sensing
applications
DS40001365F-page 1
PIC18(L)F1XK22
SR Latch
Pins I/O(1)
EUSART
Data
EEPROM
(bytes)
MSSP
SRAM
(bytes)
ECCP
Words
Timers
8-bit/16-bit
Bytes
Data Memory
Comparators
Device
Program Memory
10-bit A/D
Channels
Data Sheet Index
PIC18(L)F1XK22 Family Types
PIC18(L)F13K22
(1)
8K
4K
256
256
20
18
12-ch
2
1/3
1
1
1
Yes
PIC18(L)F14K22
(1)
16K
8K
512
256
20
18
12-ch
2
1/3
1
1
1
Yes
Note 1: One pin is input-only.
Data Sheet Index: (Unshaded devices are described in this document)
1. DS40001365
PIC18(L)F1XK22 20-Pin Flash Microcontrollers with XLP Technology
Note:
For other small form-factor package availability and marking information, please visit
http://www.microchip.com/packaging or contact your local sales office.
Pin Diagrams
VDD
RA5
RA4
RA3/MCLR/VPP
RC5
RC4
RC3/PGM
RC6
RC7
RB7
Note:
20
19
18
17
16
15
14
13
12
11
VSS
RA0/PGD
RA1/PGC
RA2
RC0
RC1
RC2
RB4
RB5
RB6
See Table 1 for location of all peripheral functions.
20-PIN QFN (4x4)
RA4
RA5
VDD
VSS
RA0/PGD
FIGURE 2:
1
2
3
4
5
6
7
8
9
10
PIC18(L)F14K22
20-PIN PDIP, SSOP, SOIC
PIC18(L)F13K22
FIGURE 1:
20 19 18 17 16
RA3/MCLR/VPP
RC5
RC4
RC3/PGM
RC6
1
15 RA1/PGC
2 PIC18(L)F13K22 14 RA2
3
PIC18(L)F14K22 13 RC0
4
12 RC1
5
11 RC2
RC7
RB7
RB6
RB5
RB4
6 7 8 9 10
Note:
See Table 1 for location of all peripheral functions.
DS40001365F-page 2
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
18
15
AN1
C12IN0-
VREF+
—
—
—
RA2
17
14
AN2
C1OUT
—
—
—
—
RA3
4
1
—
—
—
—
—
—
RA4
3
20
AN3
—
—
—
—
RA5
2
19
—
—
—
—
RB4
13
10
AN10
—
—
RB5
12
9
AN11
—
—
—
—
—
—
IOC/INT0
Basic
RA1
—
Pull-up
VREF-/
CVREF(DAC1OUT)
Interrupts
C1IN+
Timers
Reference
AN0
SR Latch
Comparator
16
MSSP
Analog
19
EUSART
20-Pin QFN
RA0
ECCP
20-Pin PDIP/SSOP/SOIC
20-PIN ALLOCATION TABLE (PIC18(L)F1XK22)
I/O
TABLE 1:
Y
PGD
IOC/INT1
Y
PGC
IOC/INT2
Y
—
—
IOC
Y
MCLR/VPP
—
—
IOC
Y
OSC2/CLKOUT
—
—
T13CKI
IOC
Y
OSC1/CLKIN
—
SDI/SDA
—
—
IOC
Y
—
RX/DT
—
—
—
IOC
Y
—
—
—
SRQ
T0CKI
—
—
—
—
—
RB6
11
8
—
—
—
—
—
SCL/SCK
—
—
IOC
Y
—
RB7
10
7
—
—
—
—
TX/CK
—
—
—
IOC
Y
—
RC0
16
13
AN4
C2IN+
—
—
—
—
—
—
—
—
—
RC1
15
12
AN5
C12IN1-
—
—
—
—
—
—
—
—
—
RC2
14
11
AN6
C12IN2-
—
P1D
—
—
—
—
—
—
—
RC3
7
4
AN7
C12IN3-
—
P1C
—
—
—
—
—
—
PGM
RC4
6
3
—
C2OUT
—
P1B
—
—
SRNQ
—
—
—
—
RC5
5
2
—
—
—
CCP1/P1A
—
—
—
—
—
—
—
RC6
8
5
AN8
—
—
—
—
SS
—
—
—
—
—
RC7
9
6
AN9
—
—
—
—
SDO
—
—
—
—
—
—
1
18
—
—
—
—
—
—
—
—
—
—
VDD
—
20
17
—
—
—
—
—
—
—
—
—
—
VSS
2009-2016 Microchip Technology Inc.
DS40001365F-page 3
PIC18(L)F1XK22
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 6
2.0 Oscillator Module........................................................................................................................................................................ 12
3.0 Memory Organization ................................................................................................................................................................. 24
4.0 Flash Program Memory .............................................................................................................................................................. 45
5.0 Data EEPROM Memory ............................................................................................................................................................. 54
6.0 8 x 8 Hardware Multiplier............................................................................................................................................................ 58
7.0 Interrupts .................................................................................................................................................................................... 60
8.0 I/O Ports ..................................................................................................................................................................................... 73
9.0 Timer0 Module ........................................................................................................................................................................... 91
10.0 Timer1 Module ........................................................................................................................................................................... 94
11.0 Timer2 Module ......................................................................................................................................................................... 100
12.0 Timer3 Module ......................................................................................................................................................................... 102
13.0 Enhanced Capture/Compare/PWM (ECCP) Module................................................................................................................ 106
14.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 127
15.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................................... 170
16.0 Analog-to-Digital Converter (ADC) Module .............................................................................................................................. 197
17.0 Comparator Module.................................................................................................................................................................. 210
18.0 Power-Managed Modes ........................................................................................................................................................... 222
19.0 SR Latch................................................................................................................................................................................... 228
20.0 Fixed Voltage Reference (FVR)................................................................................................................................................ 231
21.0 Digital-to-Analog Converter (DAC) Module .............................................................................................................................. 233
22.0 Reset ........................................................................................................................................................................................ 237
23.0 Special Features of the CPU .................................................................................................................................................... 249
24.0 Instruction Set Summary .......................................................................................................................................................... 265
25.0 Development Support............................................................................................................................................................... 315
26.0 Electrical Specifications............................................................................................................................................................ 319
27.0 DC and AC Characteristics Graphs and Charts ....................................................................................................................... 356
28.0 Packaging Information.............................................................................................................................................................. 372
Appendix A: Revision History............................................................................................................................................................. 382
Appendix B: Device Differences......................................................................................................................................................... 383
The Microchip WebSite ...................................................................................................................................................................... 384
Customer Change Notification Service .............................................................................................................................................. 384
Customer Support .............................................................................................................................................................................. 384
Product Identification System............................................................................................................................................................. 385
Worldwide Sales and Service ............................................................................................................................................................ 387
DS40001365F-page 4
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
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
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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
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Most Current Data Sheet
To obtain the most up-to-date version of this data sheet, please register at our Worldwide Website 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., DS30000000A is version A of document DS30000000).
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:
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When contacting a sales office, please specify which device, revision of silicon and data sheet (include literature number) you are
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2009-2016 Microchip Technology Inc.
DS40001365F-page 5
PIC18(L)F1XK22
1.0
DEVICE OVERVIEW
This family offers the advantages of all PIC18
microcontrollers – namely, high computational
performance with the addition of high-endurance,
Flash program memory. On top of these features, the
PIC18(L)F1XK22
family
introduces
design
enhancements that make these microcontrollers a
logical choice for many high-performance, power
sensitive applications.
1.1
1.1.1
New Core Features
XLP TECHNOLOGY
All of the devices in the PIC18(L)F1XK22 family
incorporate a range of features that can significantly
reduce power consumption during operation. Key
items include:
• 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 26.0 “Electrical Specifications”
for values.
1.1.2
MULTIPLE OSCILLATOR OPTIONS
AND FEATURES
All of the devices in the PIC18(L)F1XK22 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
• 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)
• External RC Oscillator modes with the same pin
options as the External Clock modes
• An internal oscillator block which contains a
16 MHz HFINTOSC oscillator and a 31 kHz
LFINTOSC oscillator which together provide eight
user selectable clock frequencies, from 31 kHz to
16 MHz. This option frees the two oscillator pins
for use as additional general purpose I/O.
• 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 64 MHz. Used with the internal
oscillator, the PLL gives users a complete
selection of clock speeds, from 31 kHz to 64 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 LFINTOSC. If a
clock failure occurs, the controller is switched to
the internal oscillator block, allowing for continued
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.
DS40001365F-page 6
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
1.2
Other Special Features
• Memory Endurance: The Flash cells for both
program memory and data EEPROM are rated to
last for many thousands of erase/write cycles – up to
10K for program memory and 100K 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. Using a bootloader
routine located in the code protected Boot Block,
it is possible to create an application that can
update itself in the field.
• Extended Instruction Set: The PIC18(L)F1XK22
family introduces an optional extension to the
PIC18 instruction set, which adds eight new
instructions and an Indexed Addressing mode.
This extension has been specifically designed to
optimize re-entrant application code originally
developed in high-level languages, such as C.
• Enhanced CCP module: In PWM mode, this
module provides one, two or four modulated
outputs for controlling half-bridge and full-bridge
drivers. Other features include:
- Auto-Shutdown, for disabling PWM outputs
on interrupt or other select conditions
- Auto-Restart, to reactivate outputs once the
condition has cleared
- Output steering to selectively enable one or
more of four outputs to provide the PWM
signal.
• 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.
• 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, reduce code overhead.
• Extended Watchdog Timer (WDT): This
enhanced version incorporates a 16-bit
postscaler, allowing an extended time-out range
that is stable across operating voltage and
temperature. See Section 26.0 “Electrical
Specifications” for time-out periods.
2009-2016 Microchip Technology Inc.
1.3
Details on Individual Family
Members
Devices in the PIC18(L)F1XK22 family are available in
20-pin packages. Block diagrams for the two groups
are shown in Figure 1-1.
The devices are differentiated from each other in the
following ways:
1.
Flash program memory:
• 8 Kbytes for PIC18(L)F13K22
• 16 Kbytes for PIC18(L)F14K22
All other features for devices in this family are identical.
These are summarized in Table 1-1.
The pinouts for all devices are listed in Table 1 and I/O
description are in Table 1-2.
DS40001365F-page 7
PIC18(L)F1XK22
TABLE 1-1:
DEVICE FEATURES FOR THE PIC18(L)F1XK22 (20-PIN DEVICES)
Features
Voltage Range (1.8 - 5.5V)
Program Memory (Bytes)
PIC18F13K22
PIC18LF13K22
PIC18F14K22
PIC18LF14K22
2.3-5.5V
1.8V-3.6V
2.3-5.5V
1.8V-3.6V
8K
16K
Program Memory (Instructions)
4096
8192
Data Memory (Bytes)
256
512
Operating Frequency
Interrupt Sources
I/O Ports
Timers
Enhanced Capture/ Compare/PWM Modules
Serial Communications
10-Bit Analog-to-Digital Module
Resets (and Delays)
Instruction Set
Packages
DS40001365F-page 8
DC – 64 MHz
30
Ports A, B, C
4
1
MSSP, Enhanced USART
12 Input Channels
POR, BOR, RESET Instruction, Stack Full, Stack Underflow, MCLR, WDT
(PWRT, OST)
75 Instructions, 83 with Extended Instruction Set Enabled
20-Pin PDIP, SSOP, SOIC
QFN (4x4x0.9mm)
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 1-1:
PIC18(L)F1XK22 BLOCK DIAGRAM
Data Bus
Table Pointer
Data Latch
8
8
inc/dec logic
PCLATU PCLATH
21
PORTA
Data Memory
(512/768 bytes)
Address Latch
20
PCU PCH PCL
Program Counter
12
Data Address
31-Level Stack
4
BSR
Address Latch
STKPTR
Program Memory
12
FSR0
FSR1
FSR2
Data Latch
4
Access
Bank
12
PORTB
8
inc/dec
logic
Table Latch
RA0
RA1
RA1
RA3
RA4
RA5
RB4
RB5
RB6
RB7
Address
Decode
ROM Latch
Instruction Bus
IR
Instruction
Decode and
Control
8
State machine
control signals
PRODH PRODL
PORTC
8 x 8 Multiply
3
Internal
Oscillator
Block
OSC1(2)
LFINTOSC
Oscillator
(2)
OSC2
16 MHz
Oscillator
MCLR(1)
Single-Supply
Programming
VDD, VSS
8
W
BITOP
8
Power-up
Timer
8
8
8
8
Oscillator
Start-up Timer
RC0
RC1
RC2
RC3
RC4
RC5
RC6
RC7
ALU
Power-on
Reset
8
Watchdog
Timer
Fail-Safe
Clock Monitor
Precision
Band Gap
Reference
FVR
DAC
BOR
Data
EEPROM
Timer0
Timer1
Timer2
Comparator
ECCP1
MSSP
EUSART
ADC
10-bit
FVR
CVREF/DAC1
Note
Timer3
FVR
CVREF/DAC1
1:
RA3 is only available when MCLR functionality is disabled.
2:
OSC1/CLKIN and OSC2/CLKOUT 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 Module” for additional information.
2009-2016 Microchip Technology Inc.
DS40001365F-page 9
PIC18(L)F1XK22
TABLE 1-2:
PIC18(L)F1XK22 PIN SUMMARY
PDIP/SSOP/
SOIC
QFN
Pin
Number
RA0/AN0/CVREF/VREF-/C1IN+/INT0/PGD
RA0
AN0
CVREF/DAC1OUT
VREFC1IN+
INT0
PGD
19
16
RA1/AN1/C12IN0-/VREF+/INT1/PGC
RA1
AN1
C12IN0VREF+
INT1
PGC
18
RA2/AN2/C1OUT/T0CKI/INT2/SRQ
RA2
AN2
C1OUT
T0CKI
INT2
SRQ
17
RA3/MCLR/VPP
RA3
MCLR
VPP
4
RA4/AN3/OSC2/CLKOUT
RA4
AN3
OSC2
3
Pin
Type
Buffer
Type
I/O
I
O
I
I
I
I/O
TTL
Analog
Analog
Analog
Analog
ST
ST
Digital I/O
ADC channel 0
DAC reference voltage output
ADC and DAC reference voltage (low) input
Comparator C1 noninverting input
External interrupt 0
ICSP™ programming data pin
I/O
I
1
I
I
I/O
TTL
Analog
Analog
Analog
ST
ST
Digital I/O
ADC channel 1
Comparator C1 and C2 inverting input
ADC and DAC reference voltage (high) input
External interrupt 1
ICSP programming clock pin
I/O
I
—
I
I
O
ST
Analog
CMOS
ST
ST
CMOS
Digital I/O
ADC channel 2
Comparator C1 output
Timer0 external clock input
External interrupt 2
SR latch output
I
I
P
ST
ST
—
I/O
I
O
TTL
Analog
XTAL
O
CMOS
I/O
I
TTL
XTAL
CLKIN
I
CMOS
T13CKI
I
ST
I/O
I
I
I/O
TTL
Analog
ST
ST
Pin Name
15
14
1
RB4/AN10/SDI/SDA
RB4
AN10
SDI
SDA
Legend:
TTL =
ST =
O =
XTAL=
TTL compatible input
Schmitt Trigger input
Output
Crystal Oscillator
DS40001365F-page 10
2
13
Digital input
Active-low Master Clear with internal pull-up
High voltage programming input
20
CLKOUT
RA5/OSC1/CLKIN/T13CKI
RA5
OSC1
Description
Digital I/O
ADC channel 3
Oscillator crystal output. Connect to crystal or resonator
in Crystal Oscillator mode
In RC mode, OSC2 pin outputs CLKOUT which
has 1/4 the frequency of OSC1 and denotes
the instruction cycle rate
19
Digital I/O
Oscillator crystal input or external clock input
ST buffer when configured in RC mode; analog other
wise
External clock source input. Always associated with the
pin function OSC1 (See related OSC1/CLKIN, OSC2,
CLKOUT pins
Timer0 and Timer3 external clock input
10
Digital I/O
ADC channel 10
SPI data in
I2C data I/O
CMOS = CMOS compatible input or output
I
= Input
P
= Power
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 1-2:
PIC18(L)F1XK22 PIN SUMMARY (CONTINUED)
PDIP/SSOP/
SOIC
QFN
Pin
Number
RB5/AN11/RX/DT
RB5
AN11
RX
DT
12
9
RB6/SCK/SCL
RB6
SCK
SCL
11
RB7/TX/CK
RB7
TX
CK
10
RC0/AN4/C2IN+
RC0
AN4
C2IN+
16
RC1/AN5/C12INRC1
AN5
C12IN-
15
RC2/AN6/C12IN2-/P1D
RC2
AN6
C12IN2P1D
14
RC3/AN7/C12IN3-/P1C/PGM
RC3
AN7
C12IN3P1C
PGM
7
RC4/C2OUT/P1B/SRNQ
RC4
C2OUT
P1B
SRNQ
6
RC5/CCP1/P1A
RC5
CCP1
P1A
5
RC6/AN8/SS
RC6
AN8
SS
8
RC7/AN9/SDO
RC7
AN9
SDO
9
VSS
20
17
P
—
VDD
1
18
P
—
Pin Name
Legend:
TTL =
ST =
O =
XTAL=
TTL compatible input
Schmitt Trigger input
Output
Crystal Oscillator
2009-2016 Microchip Technology Inc.
Pin
Type
Buffer
Type
I/O
I
I
I/O
TLL
Analog
ST
ST
I/O
I/O
I/O
TLL
ST
ST
I/O
O
I/O
TLL
CMOS
ST
Digital I/O
EUSART asynchronous transmit
EUSART synchronous clock (see related RX/DT)
I/O
I
I
ST
Analog
Analog
Digital I/O
ADC channel 4
Comparator C2 noninverting input
I/O
I
I
ST
Analog
Analog
Digital I/O
ADC channel 5
Comparator C1 and C2 inverting input
I/O
I
I
O
ST
Analog
Analog
CMOS
Digital I/O
ADC channel 6
Comparator C1 and C2 inverting input
Enhanced CCP1 PWM output
I/O
I
I
O
I/O
ST
Analog
Analog
CMOS
ST
Digital I/O
ADC channel 7
Comparator C1 and C2 inverting input
Enhanced CCP1 PWM output
Low-Voltage ICSP Programming enable pin
I/O
O
O
O
ST
CMOS
CMOS
CMOS
Digital I/O
Comparator C2 output
Enhanced CCP1 PWM output
SR latch inverted output
I/O
I/O
O
ST
ST
CMOS
Digital I/O
Capture 1 input/Compare 1 output/PWM 1 output
Enhanced CCP1 PWM output
I/O
I
I
ST
Analog
TTL
Digital I/O
ADC channel 8
SPI slave select input
I/O
I
O
ST
Analog
CMOS
Digital I/O
ADC channel 9
SPI data out
Description
Digital I/O
ADC channel 11
EUSART asynchronous receive
EUSART synchronous data (see related RX/TX)
8
Digital I/O
Synchronous serial clock input/output for SPI mode
Synchronous serial clock input/output for I2C mode
7
13
12
11
4
3
2
5
6
Ground reference for logic and I/O pins
Positive supply for logic and I/O pins
CMOS = CMOS compatible input or output
I
= Input
P
= Power
DS40001365F-page 11
PIC18(L)F1XK22
2.0
OSCILLATOR MODULE
2.3
2.1
Overview
The SCS bits of the OSCCON register select between
the following clock sources:
The oscillator module has a variety of clock sources
and features that allow it to be used in a wide range of
applications, maximizing performance and minimizing
power consumption. Figure 2-1 illustrates a block
diagram of the oscillator module.
• Primary External Oscillator
• Secondary External Oscillator
• Internal Oscillator
Note:
Key features of the oscillator module include:
• System Clocks
• System Clock Selection
- Primary External Oscillator
- Secondary External Oscillator
- Internal Oscillator
• Oscillator Start-up Timer
• System Clock Selection
• Clock Switching
• 4x Phase Lock Loop Frequency Multiplier
• CPU Clock Divider
• Two-Speed Start-up Mode
• Fail-Safe Clock Monitoring
2.2
System Clocks
The PIC18(L)F1XK22 can be operated in 13 different
oscillator modes. The user can program these using
the available Configuration bits. In addition, clock
support functions such as Fail-Safe and two Start-up
can also be configured.
The available Primary oscillator options include:
•
•
•
•
•
•
•
•
•
•
•
•
•
External Clock, low power (ECL)
External Clock, medium power (ECM)
External Clock, high power (ECH)
External Clock, low power, CLKOUT function on
RA4/OSC2 (ECCLKOUTL)
External Clock, medium power, CLKOUT function
on RA4/OSC2 (ECCLKOUTM)
External Clock, high power, CLKOUT function on
RA4/OSC2 (ECCLKOUTH)
External Crystal (XT)
High-speed Crystal (HS)
Low-power crystal (LP)
External Resistor/Capacitor (EXTRC)
External RC, CLKOUT function on RA4/OSC2
31.25 kHz – 16 MHz internal oscillator (INTOSC)
31.25 kHz – 16 MHz internal oscillator, CLKOUT
function on RA4/OSC2
System Clock Selection
The frequency of the system clock will be
referred to as FOSC throughout this
document.
TABLE 2-1:
SYSTEM CLOCK SELECTION
Configuration
Selection
SCS
System Clock
1x
Internal Oscillator
01
Secondary External Oscillator
00
(Default after Reset)
Oscillator defined by
FOSC
The default state of the SCS bits sets the system clock
to be the oscillator defined by the FOSC bits of the
CONFIG1H Configuration register. The system clock
will always be defined by the FOSC bits until the SCS
bits are modified in software.
When the Internal Oscillator is selected as the system
clock, the IRCF bits of the OSCCON register and the
INTSRC bit of the OSCTUNE register will select either
the LFINTOSC or the HFINTOSC. The LFINTOSC is
selected when the IRCF = 000 and the INTSRC
bit is clear. All other combinations of the IRCF bits and
the INTSRC bit will select the HFINTOSC as the
system clock.
2.4
Primary External Oscillator
The Primary External Oscillator’s mode of operation is
selected by setting the FOSC bits of the
CONFIG1H Configuration register. The oscillator can
be set to the following modes:
•
•
•
•
•
LP: Low-Power Crystal
XT: Crystal/Ceramic Resonator
HS: High-Speed Crystal Resonator
RC: External RC Oscillator
EC: External Clock
Additionally, the Primary External Oscillator may be
shut down under firmware control to save power.
Additionally, the 4x PLL may be enabled in hardware or
software (under certain conditions) for increased
oscillator speed.
DS40001365F-page 12
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 2-1:
OSC1/T13CKI
PIC® MCU CLOCK SOURCE BLOCK DIAGRAM
Primary
Oscillator,
External
and
Secondary
Oscillator
PIC18(L)F1XK22
Timer1/Timer3
Sleep
OSC2
PCLKEN
PRI_SD
LP, XT, HS, RC, EC,
1 Secondary Osc.
4 x PLL
IDLEN
Sleep
0x
0
FOSC
Peripherals
PLL_EN
PLLEN
Internal Osc.
1x
MUX
T1OSCEN
System
Clock
IRCF
CPU
Sleep
16 MHz
31 kHz
LFINTOSC
4 MHz
2 MHz
1 MHz
500 kHz
110
101
100
011
MUX
8 MHz
Postscaler
Internal
Oscillator
Block
16 MHz
HFINTOSC
Clock
Control
FOSC
SCS
010
250 kHz
001
1 31 kHz
000
0
INTSRC
Fail-Safe
Clock
Watchdog
Timer
Note:
Two-Speed
Start-up
If using a low-frequency external oscillator
and want to multiple it by 4 via PLL, the
ideal input frequency is from 4 MHz to
16 MHz.
2009-2016 Microchip Technology Inc.
DS40001365F-page 13
PIC18(L)F1XK22
2.4.1
PRIMARY EXTERNAL OSCILLATOR
SHUTDOWN
The Primary External Oscillator can be enabled or
disabled via software. To enable software control of the
Primary External Oscillator, the PCLKEN bit of the
CONFIG1H Configuration register must be set. With
the PCLKEN bit set, the Primary External Oscillator is
controlled by the PRI_SD bit of the OSCCON2 register.
The Primary External Oscillator will be enabled when
the PRI_SD bit is set, and disabled when the PRI_SD
bit is clear.
Note:
2.4.2
The Primary External Oscillator cannot be
shut down when it is selected as the
System Clock. To shut down the oscillator,
the system clock source must be either
the Secondary Oscillator or the Internal
Oscillator.
LP, XT AND HS OSCILLATOR
MODES
FIGURE 2-2:
QUARTZ CRYSTAL
OPERATION (LP, XT OR
HS MODE)
PIC® MCU
OSC1/CLKIN
C1
To Internal
Logic
Quartz
Crystal
C2
RS(1)
RF(2)
Sleep
OSC2/CLKOUT
Note 1:
A series resistor (RS) may be required for
quartz crystals with low drive level.
2:
The value of RF varies with the Oscillator mode
selected (typically between 2 M to 10 M.
The LP, XT and HS modes support the use of quartz
crystal resonators or ceramic resonators connected to
OSC1 and OSC2 (Figure 2-2). The mode selects a low,
medium or high gain setting of the internal inverteramplifier to support various resonator types and speed.
Note 1: Quartz
crystal
characteristics
vary
according to type, package and
manufacturer. The user should consult the
manufacturer data sheets for specifications
and recommended application.
LP Oscillator mode selects the lowest gain setting of the
internal inverter-amplifier. LP mode current consumption
is the least of the three modes. This mode is best suited
to drive resonators with a low drive level specification, for
example, tuning fork type crystals.
2: Always verify oscillator performance over
the VDD and temperature range that is
expected for the application.
XT Oscillator mode selects the intermediate gain
setting of the internal inverter-amplifier. XT mode
current consumption is the medium of the three modes.
This mode is best suited to drive resonators with a
medium drive level specification.
• AN826, Crystal Oscillator Basics and
Crystal Selection for rfPIC® and
PICmicro® Devices (DS00826)
• AN849, Basic PICmicro® Oscillator
Design (DS00849)
• AN943, Practical PICmicro® Oscillator
Analysis and Design (DS00943)
• AN949, Making Your Oscillator Work
(DS00949)
HS Oscillator mode selects the highest gain setting of the
internal inverter-amplifier. HS mode current consumption
is the highest of the three modes. This mode is best
suited for resonators that require a high drive setting.
3: For oscillator design assistance, reference
the following Microchip Applications Notes:
Figure 2-2 and Figure 2-3 show typical circuits for
quartz crystal and ceramic resonators, respectively.
DS40001365F-page 14
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 2-3:
CERAMIC RESONATOR
OPERATION
(XT OR HS MODE)
PIC® MCU
OSC1/CLKIN
C1
To Internal
Logic
RP(3)
RF(2)
C2 Ceramic
RS(1)
Resonator
Sleep
OSC2/CLKOUT
Note 1: A series resistor (RS) may be required for
ceramic resonators with low drive level.
2: The value of RF varies with the Oscillator mode
selected (typically between 2 M to 10 M.
3: An additional parallel feedback resistor (RP)
may be required for proper ceramic resonator
operation.
2.4.3
EXTERNAL RC
The External Resistor-Capacitor (RC) mode supports
the use of an external RC circuit. This allows the
designer maximum flexibility in frequency choice while
keeping costs to a minimum when clock accuracy is not
required. In RC mode, the RC circuit connects to OSC1,
allowing OSC2 to be configured as an I/O or as
CLKOUT. The CLKOUT function is selected by the
FOSC bits of the CONFIG1H Configuration register.
When OSC2 is configured as CLKOUT, the frequency
at the pin is the frequency of the RC oscillator divided by
4. Figure 2-4 shows the external RC mode connections.
FIGURE 2-4:
VDD
The RC oscillator frequency is a function of the supply
voltage, the resistor REXT, the capacitor CEXT and the
operating temperature. Other factors affecting the
oscillator frequency are:
• Input threshold voltage variation
• Component tolerances
• Variation in capacitance due to packaging
2.4.4
EXTERNAL CLOCK
The External Clock (EC) mode allows an externally
generated logic level clock to be used as the system’s
clock source. When operating in this mode, the
external clock source is connected to the OSC1
allowing OSC2 to be configured as an I/O or as
CLKOUT. The CLKOUT function is selected by the
FOSC bits of the CONFIG1H Configuration register.
When OSC2 is configured as CLKOUT, the frequency
at the pin is the frequency of the EC oscillator divided
by 4.
Three different power settings are available for EC
mode. The power settings allow for a reduced IDD of the
device, if the EC clock is known to be in a specific
range. If there is an expected range of frequencies for
the EC clock, select the power mode for the highest
frequency.
EC
Low power
0 – 250 kHz
EC
Medium power
250 kHz – 4 MHz
EC
High power
4 – 64 MHz
2.5
Secondary External Oscillator
The Secondary External Oscillator is designed to drive
an external 32.768 kHz crystal. This oscillator is
enabled or disabled by the T1OSCEN bit of the T1CON
register. See Section 10.0 “Timer1 Module” for more
information.
EXTERNAL RC MODES
PIC® MCU
REXT
OSC1/CLKIN
Internal
Clock
CEXT
VSS
FOSC/4 or
I/O(2)
OSC2/CLKOUT(1)
Recommended values: 10 k REXT 100 k
CEXT > 20 pF
Note 1:
2:
Alternate pin functions are listed in
Section 1.0 “Device Overview”.
Output depends upon RC or RCIO clock mode.
2009-2016 Microchip Technology Inc.
DS40001365F-page 15
PIC18(L)F1XK22
2.6
Internal Oscillator
The internal oscillator module contains two independent
oscillators which are:
• LFINTOSC: Low-Frequency Internal Oscillator
• HFINTOSC: High-Frequency Internal Oscillator
When operating with either oscillator, OSC1 will be an
I/O and OSC2 will be either an I/O or CLKOUT. The
CLKOUT function is selected by the FOSC bits of the
CONFIG1H Configuration register. When OSC2 is
configured as CLKOUT, the frequency at the pin is the
frequency of the Internal Oscillator divided by 4.
2.6.1
LFINTOSC
The Low-Frequency Internal Oscillator (LFINTOSC) is
a 31 kHz internal clock source. The LFINTOSC
oscillator is the clock source for:
• Power-up Timer
• Watchdog Timer
• Fail-Safe Clock Monitor
The LFINTOSC is enabled when any of the following
conditions are true:
• Power-up Timer is enabled (PWRTEN = 0)
• Watchdog Timer is enabled (WDTEN = 1)
• Watchdog Timer is enabled by software
(WDTEN = 0 and SWDTEN = 1)
• Fail-Safe Clock Monitor is enabled (FCMEM = 1)
• SCS1 = 1 and IRCF = 000 and INTSRC = 0
• FOSC selects the internal oscillator as the
primary clock and IRCF = 000 and
INTSRC = 0
• IESO = 1 (Two-Speed Start-up) and
IRCF = 000 and INTSRC = 0
DS40001365F-page 16
2.6.2
HFINTOSC
The High-Frequency Internal Oscillator (HFINTOSC) is
a precision oscillator that is factory-calibrated to
operate at 16 MHz. The output of the HFINTOSC
connects to a postscaler and a multiplexer (see
Figure 2-1). One of eight frequencies can be selected
using the IRCF bits of the OSCCON register. The
following frequencies are available from the
HFINTOSC:
•
•
•
•
•
•
•
•
16 MHZ
8 MHZ
4 MHZ
2 MHZ
1 MHZ (Default after Reset)
500 kHz
250 kHz
31 kHz
The HFIOFS bit of the OSCCON register indicates
whether the HFINTOSC is stable.
Note 1: Selecting 31 kHz from the HFINTOSC
oscillator requires IRCF = 000 and
the INTSRC bit of the OSCTUNE register
to be set. If the INTSRC bit is clear, the
system clock will come from the
LFINTOSC.
2: Additional adjustments to the frequency
of the HFINTOSC can made via the
OSCTUNE registers. See Register 2-3
for more details.
The HFINTOSC is enabled if any of the following
conditions are true:
• SCS1 = 1 and IRCF 000
• SCS1 = 1 and IRCF = 000 and INTSRC = 1
• FOSC selects the internal oscillator as the
primary clock and
- IRCF 000 or
- IRCF = 000 and INTSRC = 1
• IESO = 1 (Two-Speed Start-up) and
- IRCF 000 or
- IRCF = 000 and INTSRC = 1
• FCMEM = 1 (Fail-Safe Clock Monitoring) and
- IRCF 000 or
- IRCF = 000 and INTSRC = 1
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
2.7
Oscillator Control
The Oscillator Control (OSCCON) (Register 2-1) and the
Oscillator Control 2 (OSCCON2) (Register 2-2) registers
control the system clock and frequency selection
options.
REGISTER 2-1:
OSCCON: OSCILLATOR CONTROL REGISTER
R/W-0
R/W-0
R/W-1
R/W-1
R-q
R-0
R/W-0
R/W-0
IDLEN
IRCF2
IRCF1
IRCF0
OSTS(1)
HFIOFS
SCS1
SCS0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
q = depends on condition
-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
IRCF: Internal Oscillator Frequency Select bits
111 = 16 MHz
110 = 8 MHz
101 = 4 MHz
100 = 2 MHz
011 = 1 MHz(3)
010 = 500 kHz
001 = 250 kHz
000 = 31 kHz(2)
bit 3
OSTS: Oscillator Start-up Time-out Status bit(1)
1 = Device is running from the clock defined by FOSC of the CONFIG1 register
0 = Device is running from the internal oscillator (HFINTOSC or LFINTOSC)
bit 2
HFIOFS: HFINTOSC Frequency Stable bit
1 = HFINTOSC frequency is stable
0 = HFINTOSC frequency is not stable
bit 1-0
SCS: System Clock Select bits
1x = Internal oscillator block
01 = Secondary (Timer1) oscillator
00 = Primary clock (determined by CONFIG1H[FOSC]).
Note 1:
2:
3:
Reset state depends on state of the IESO Configuration bit.
Source selected by the INTSRC bit of the OSCTUNE register, see text.
Default output frequency of HFINTOSC on Reset.
2009-2016 Microchip Technology Inc.
DS40001365F-page 17
PIC18(L)F1XK22
REGISTER 2-2:
OSCCON2: OSCILLATOR CONTROL REGISTER 2
U-0
U-0
U-0
U-0
U-0
R/W-1
R/W-0
R-x
—
—
—
—
—
PRI_SD
HFIOFL
LFIOFS
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
q = depends on condition
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-3
Unimplemented: Read as ‘0’
bit 2
PRI_SD: Primary Oscillator Drive Circuit shutdown bit
1 = Oscillator drive circuit on
0 = Oscillator drive circuit off (zero power)
bit 1
HFIOFL: HFINTOSC Frequency Locked bit
1 = HFINTOSC is in lock
0 = HFINTOSC has not yet locked
bit 0
LFIOFS: LFINTOSC Frequency Stable bit
1 = LFINTOSC is stable
0 = LFINTOSC is not stable
DS40001365F-page 18
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
2.7.1
OSCTUNE REGISTER
The HFINTOSC is factory-calibrated, but can be
adjusted in software by writing to the TUN bits of
the OSCTUNE register (Register 2-3).
The default value of the TUN is ‘000000’. The
value is a 6-bit two’s complement number.
When the OSCTUNE register is modified, the
HFINTOSC frequency will begin shifting to the new
frequency. Code execution continues during this shift,
while giving no indication that the shift has occurred.
OSCTUNE does not affect the LFINTOSC frequency.
The operation of features that depend on the LFINTOSC
clock source frequency, such as the Power-up Timer
REGISTER 2-3:
(PWRT), Watchdog Timer (WDT), Fail-Safe Clock
Monitor (FSCM) and peripherals, are not affected by the
change in frequency.
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 2.6.1 “LFINTOSC”.
The PLLEN bit controls the operation of the frequency
multiplier. For more details about the function of the
PLLEN bit see Section 2.10 “4x Phase Lock Loop
Frequency Multiplier”.
OSCTUNE: OSCILLATOR TUNING REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
INTSRC
PLLEN
TUN5
TUN4
TUN3
TUN2
TUN1
TUN0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
INTSRC: Internal Oscillator Low-Frequency Source Select bit
1 = 31.25 kHz device clock derived from 16 MHz HFINTOSC source (divide-by-512 enabled)
0 = 31 kHz device clock derived directly from LFINTOSC internal oscillator
bit 6
PLLEN: Frequency Multiplier PLL bit
1 = PLL enabled (for HFINTOSC 8 MHz and 16 MHz only)
0 = PLL disabled
bit 5-0
TUN: Frequency Tuning bits
011111 = Maximum frequency
011110 =
•••
000001 =
000000 = Oscillator module is running at the factory-calibrated frequency.
111111 =
•••
100000 = Minimum frequency
2009-2016 Microchip Technology Inc.
DS40001365F-page 19
PIC18(L)F1XK22
2.8
Oscillator Start-up Timer
The Primary External Oscillator, when configured for
LP, XT or HS modes, incorporates an Oscillator Start-up
Timer (OST). The OST ensures that the oscillator starts
and provides a stable clock to the oscillator module.
The OST times out when 1024 oscillations on OSC1
have occurred. During the OST period, with the system
clock set to the Primary External Oscillator, the program
counter does not increment suspending program
execution. The OST period will occur following:
•
•
•
•
•
Power-on Reset (POR)
Brown-out Reset (BOR)
Wake-up from Sleep
Oscillator being enabled
Expiration of Power-up Timer (PWRT)
In order to minimize latency between external oscillator
start-up and code execution, the Two-Speed Start-up
mode can be selected. See Section 2.11 “Two-Speed
Start-up Mode” for more information.
2.9
Clock Switching
The device contains circuitry to prevent clock “glitches”
due to a change of the system clock source. To
accomplish this, a short pause in the system clock
occurs during the clock switch. If the new clock source
is not stable (e.g., OST is active), the device will
continue to execute from the old clock source until the
new clock source becomes stable. The timing of a
clock switch is as follows:
1.
2.
3.
4.
5.
6.
7.
SCS bits of the OSCCON register are
modified.
The system clock will continue to operate from
the old clock until the new clock is ready.
Clock switch circuitry waits for two consecutive
rising edges of the old clock after the new clock
is ready.
The system clock is held low, starting at the next
falling edge of the old clock.
Clock switch circuitry waits for an additional two
rising edges of the new clock.
On the next falling edge of the new clock, the
low hold on the system clock is release and the
new clock is switched in as the system clock.
Clock switch is complete.
Refer to Figure 2-5 for more details.
FIGURE 2-5:
High Speed
CLOCK SWITCH TIMING
Low Speed
Old Clock
Start-up Time(1)
Clock Sync
Running
New Clock
New Clk Ready
IRCF Select Old
Select New
System Clock
Low Speed
High Speed
Old Clock
Start-up Time(1)
Clock Sync
Running
New Clock
New Clk Ready
IRCF Select Old
Select New
System Clock
Note 1: Start-up time includes TOST (1024 TOSC) for external clocks, plus TPLL (approx. 2 ms) for HSPLL mode.
DS40001365F-page 20
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 2-2:
EXAMPLES OF DELAYS DUE TO CLOCK SWITCHING
Switch From
Switch To
Oscillator Delay
Sleep/POR
LFINTOSC
HFINTOSC
Oscillator Warm-up Delay (TWARM)
Sleep/POR
LP, XT, HS
1024 clock cycles
Sleep/POR
EC, RC
8 Clock Cycles
2.10
4x Phase Lock Loop Frequency
Multiplier
A Phase Locked Loop (PLL) circuit is provided as an
option for users who wish to use a lower-frequency
external oscillator or to operate at 32 MHz or 64 MHz
with the HFINTOSC. The PLL is designed for an input
frequency from 4 MHz to 16 MHz. The PLL multiplies
its input frequency by a factor of four when the PLL is
enabled. This may be useful for customers who are
concerned with EMI, due to high-frequency crystals.
Two bits control the PLL: the PLL_EN bit of the
CONFIG1H Configuration register and the PLLEN bit of
the OSCTUNE register. The PLL is enabled when the
PLL_EN bit is set and it is under software control when
the PLL_EN bit is cleared. Refer to Table 2-3 and
Table 2-4 for more information.
2.11
Two-Speed Start-up Mode
Two-Speed Start-up mode provides additional power
savings by minimizing the latency between external
Oscillator Start-up Timer (OST) and code execution. In
applications that make heavy use of the Sleep mode,
Two-Speed Start-up will remove the OST period, which
can reduce the overall power consumption of the
device.
Two-Speed Start-up mode is enabled by setting the
IESO bit of the CONFIG1H Configuration register. With
Two-Speed Start-up enabled, the device will execute
instructions using the internal oscillator during the
Primary External Oscillator OST period.
PLL_EN
PLLEN
PLL Status
1
x
PLL enabled
0
1
PLL enabled
When the system clock is set to the Primary External
Oscillator and the oscillator is configured for LP, XT or
HS modes, the device will not execute code during the
OST period. The OST will suspend program execution
until 1024 oscillations are counted. Two-Speed Start-up
mode minimizes the delay in code execution by
operating from the internal oscillator while the OST is
active. The system clock will switch back to the Primary
External Oscillator after the OST period has expired.
0
0
PLL disabled
Two-speed Start-up will become active after:
TABLE 2-3:
TABLE 2-4:
PLL CONFIGURATION
PLL CONFIG1H/SOFTWARE
ENABLE CLOCK SOURCE
RESTRICTIONS
Mode
PLL CONFIG1H
Enable (PLL_EN)
PLL Software
Enable (PLLEN)
LP
Yes
No
XT
Yes
No
HS
Yes
No
EC
Yes
No
EXTRC
Yes
No
LF INTOSC
No
No
HF INTOSC
8/16 MHz
8/16 MHz
2009-2016 Microchip Technology Inc.
• Power-on Reset (POR)
• Power-up Timer (PWRT), if enabled
• Wake-up from Sleep
The OSTS bit of the OSCCON register reports which
oscillator the device is currently using for operation.
The device is running from the oscillator defined by the
FOSC bits of the CONFIG1H Configuration register
when the OSTS bit is set. The device is running from
the internal oscillator when the OSTS bit is clear.
DS40001365F-page 21
PIC18(L)F1XK22
2.12
2.12.3
Fail-Safe Clock Monitor
The Fail-Safe Clock Monitor (FSCM) allows the device
to continue operating should the external oscillator fail.
The FSCM can detect oscillator failure any time after
the Oscillator Start-up Timer (OST) has expired. The
FSCM is enabled by setting the FCMEN bit in the
CONFIG1H Configuration register. The FSCM is
applicable to all external oscillator modes (LP, XT, HS,
EC and RC).
FIGURE 2-6:
FSCM BLOCK DIAGRAM
Clock Monitor
Latch
External
Clock
S
LFINTOSC
Oscillator
÷ 64
31 kHz
(~32 s)
488 Hz
(~2 ms)
R
Q
Sample Clock
2.12.1
Clock
Failure
Detected
FAIL-SAFE DETECTION
The FSCM module detects a failed oscillator by
comparing the external oscillator to the FSCM sample
clock. The sample clock is generated by dividing the
LFINTOSC by 64. See Figure 2-6. Inside the fail
detector block is a latch. The external clock sets the
latch on each falling edge of the external clock. The
sample clock clears the latch on each rising edge of the
sample clock. A failure is detected when an entire halfcycle of the sample clock elapses before the primary
clock goes low.
2.12.2
The Fail-Safe condition is cleared by either one of the
following:
• Any Reset
• By toggling the SCS1 bit of the OSCCON register
Both of these conditions restart the OST. While the
OST is running, the device continues to operate from
the INTOSC selected in OSCCON. When the OST
times out, the Fail-Safe condition is cleared and the
device automatically switches over to the external clock
source. The Fail-Safe condition need not be cleared
before the OSCFIF flag is cleared.
2.12.4
Q
FAIL-SAFE CONDITION CLEARING
RESET OR WAKE-UP FROM SLEEP
The FSCM is designed to detect an oscillator failure
after the Oscillator Start-up Timer (OST) has expired.
The OST is used after waking up from Sleep and after
any type of Reset. The OST is not used with the EC or
RC Clock modes so that the FSCM will be active as
soon as the Reset or wake-up has completed. When
the FSCM is enabled, the Two-Speed Start-up is also
enabled. Therefore, the device will always be executing
code while the OST is operating.
Note:
Due to the wide range of oscillator start-up
times, the Fail-Safe circuit is not active
during oscillator start-up (i.e., after exiting
Reset or Sleep). After an appropriate
amount of time, the user should check the
OSTS bit of the OSCCON register to verify
the oscillator start-up and that the system
clock
switchover
has
successfully
completed.
FAIL-SAFE OPERATION
When the external clock fails, the FSCM switches the
device clock to an internal clock source and sets the bit
flag OSCFIF of the PIR2 register. The OSCFIF flag will
generate an interrupt if the OSCFIE bit of the PIE2
register is also set. The device firmware can then take
steps to mitigate the problems that may arise from a
failed clock. The system clock will continue to be
sourced from the internal clock source until the device
firmware successfully restarts the external oscillator
and switches back to external operation. An automatic
transition back to the failed clock source will not occur.
The internal clock source chosen by the FSCM is
determined by the IRCF bits of the OSCCON
register. This allows the internal oscillator to be
configured before a failure occurs.
DS40001365F-page 22
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 2-7:
FSCM TIMING DIAGRAM
Sample Clock
Oscillator
Failure
System
Clock
Output
Clock Monitor Output
(Q)
Failure
Detected
OSCFIF
Test
Note:
TABLE 2-5:
Name
CONFIG1H
Test
Test
The system clock is normally at a much higher frequency than the sample clock. The relative frequencies in
this example have been chosen for clarity.
SUMMARY OF REGISTERS ASSOCIATED WITH CLOCK SOURCES
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values on
page
IESO
FCMEN
PCLKEN
PLL_EN
FOSC3
FOSC2
FOSC1
FOSC0
251
INTCON
GIE/GIEH
PEIE/GIEL
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
OSCCON
IDLEN
IRCF2
IRCF1
IRCF0
OSTS
HFIOFS
SCS1
SCS0
246
OSCCON2
—
—
—
—
—
PRI_SD
HFIOFL
LFIOFS
246
OSCTUNE
INTSRC
PLLEN
TUN5
TUN4
TUN3
TUN2
TUN1
TUN0
248
IPR2
OSCFIP
C1IP
C2IP
EEIP
BCLIP
—
TMR3IP
—
248
PIE2
OSCFIE
C1IE
C2IE
EEIE
BCLIE
—
TMR3IE
—
248
PIR2
OSCFIF
C1IF
C2IF
EEIF
BCLIF
—
TMR3IF
—
248
RD16
T1RUN
T1CKPS1
T1CKPS0
T1OSCEN
T1SYNC
TMR1CS
TMR1ON
246
T1CON
Legend:
Note 1:
x = unknown, u = unchanged, – = unimplemented locations read as ‘0’. Shaded cells are not used by oscillators.
Other (non Power-up) Resets include MCLR Reset and Watchdog Timer Reset during normal operation.
2009-2016 Microchip Technology Inc.
DS40001365F-page 23
PIC18(L)F1XK22
3.0
MEMORY ORGANIZATION
3.1
There are three types of memory in PIC18 Enhanced
microcontroller devices:
• Program Memory
• Data RAM
• Data EEPROM
Program Memory Organization
PIC18 microcontrollers implement a 21-bit program
counter, which is capable of addressing a 2-Mbyte
Program Memory (PC) 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).
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.
This family of devices contain the following:
Additional detailed information on the operation of the
Flash program memory is provided in Section 4.0
“Flash Program Memory”. Data EEPROM is
discussed separately in Section 5.0 “Data EEPROM
Memory”.
PIC18 devices have two interrupt vectors and one
Reset vector. The Reset vector address is at 0000h
and the interrupt vector addresses are at 0008h and
0018h.
FIGURE 3-1:
• PIC18(L)F13K22: 8 Kbytes of Flash Memory, up to
4,096 single-word instructions
• PIC18(L)F14K22: 16 Kbytes of Flash Memory, up
to 8,192 single-word instructions
The program memory map for PIC18(L)F1XK22
devices is shown in Figure 3-1. Memory block details
are shown in Figure 3-2.
PROGRAM MEMORY MAP AND STACK FOR PIC18(L)F1XK22 DEVICES
PC
21
CALL,RCALL,RETURN
RETFIE,RETLW
Stack Level 1
Stack Level 31
2000h
0000h
High Priority Interrupt Vector
0008h
Low Priority Interrupt Vector
0018h
On-Chip
Program Memory
3FFFh
4000h
PIC18(L)F13K22
User Memory Space
On-Chip
Program Memory
1FFFh
Reset Vector
PIC18(L)F14K22
Read ‘0’
Read ‘0’
1FFFFFh
200000h
DS40001365F-page 24
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
3.1.1
PROGRAM COUNTER
The Program Counter (PC) specifies the address of the
instruction to fetch for execution. The PC is 21-bit 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 bits; it is not directly readable or writable.
Updates to the PCH register are performed through the
PCLATH register. The upper byte is called PCU. This
register contains the PC bits; it is also not
directly readable or writable. Updates to the PCU
register are performed through the PCLATU register.
The contents of PCLATH and PCLATU are transferred
to the program counter by any operation that writes
PCL. Similarly, the upper two bytes of the program
counter are transferred to PCLATH and PCLATU by an
operation that reads PCL. This is useful for computed
offsets to the PC (see Section 3.1.4.1 “Computed
GOTO”).
The PC addresses bytes in the program memory. To
prevent the PC from becoming misaligned with word
instructions, the Least Significant bit (LSb) 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.
3.1.2
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.
FIGURE 3-2:
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-ofStack (TOS) Special File 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 or has overflowed or has underflowed.
3.1.2.1
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 3-2). 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.
RETURN ADDRESS STACK AND ASSOCIATED REGISTERS
Return Address Stack
11111
11110
11101
Top-of-Stack Registers
TOSU
00h
TOSH
1Ah
2009-2016 Microchip Technology Inc.
STKPTR
00010
TOSL
34h
Top-of-Stack
Stack Pointer
001A34h
000D58h
00011
00010
00001
00000
DS40001365F-page 25
PIC18(L)F1XK22
3.1.2.2
Return Stack Pointer (STKPTR)
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.
The STKPTR register (Figure 3-1) contains the Stack
Pointer value, the STKFUL (Stack Full) bit and the
STKUNF (Stack Underflow) 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.
Note:
After the PC is pushed onto the stack 31 times (without
popping any values off the stack), the STKFUL bit is
set. The STKOVF bit is cleared by software or by a
POR.
3.1.2.3
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 execution
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 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 23.1 “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 STKOVF bit and reset the
device. The STKOVF bit will remain set and the Stack
Pointer will be set to zero.
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.
If STVREN is cleared, the STKOVF 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.
REGISTER 3-1:
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.
The POP instruction discards the current TOS by
decrementing the Stack Pointer. The previous value
pushed onto the stack then becomes the TOS value.
STKPTR: STACK POINTER REGISTER
R/C-0
R/C-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
STKOVF(1)
STKUNF(1)
—
SP4
SP3
SP2
SP1
SP0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented
C = Clearable only bit
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
STKOVF: Stack Overflow 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
SP: Stack Pointer Location bits
Note 1:
Bit 7 and bit 6 are cleared by user software or by a POR.
DS40001365F-page 26
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
3.1.2.4
Stack Overflow 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 STKOVF or
STKUNF bit and then cause a device Reset. When
STVREN is cleared, a full or underflow condition will set
the appropriate STKOVF or STKUNF bit but not cause
a device Reset. The STKOVF or STKUNF bits are
cleared by the user software or a Power-on Reset.
3.1.3
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
register when the processor vectors for an interrupt. All
interrupt sources will push values into the stack
registers. The values in the registers are then loaded
back into 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 register
values stored by the low priority interrupt will be
overwritten. In these cases, users must save the key
registers by software during a low priority interrupt.
If interrupt priority is not used, all interrupts may use the
fast register stack for returns from interrupt. If no
interrupts are used, the fast register stack can be used
to restore the STATUS, WREG and BSR registers at
the end of a subroutine call. To use the fast register
stack for a subroutine call, a CALL label, FAST
instruction must be executed to save the STATUS,
WREG and BSR registers to the fast register stack. A
RETURN, FAST instruction is then executed to restore
these registers from the fast register stack.
Example 3-1 shows a source code example that uses
the fast register stack during a subroutine call and
return.
EXAMPLE 3-1:
CALL SUB1, FAST
FAST REGISTER STACK
CODE EXAMPLE
;STATUS, WREG, BSR
;SAVED IN FAST REGISTER
;STACK
RETURN, FAST
SUB1
;RESTORE VALUES SAVED
;IN FAST REGISTER STACK
2009-2016 Microchip Technology Inc.
3.1.4
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
3.1.4.1
Computed GOTO
A computed GOTO is accomplished by adding an offset
to the program counter. An example is shown in
Example 3-2.
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 3-2:
ORG
TABLE
3.1.4.2
MOVF
CALL
nn00h
ADDWF
RETLW
RETLW
RETLW
.
.
.
COMPUTED GOTO USING
AN OFFSET VALUE
OFFSET, W
TABLE
PCL
nnh
nnh
nnh
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 4.1 “Table Reads and Table
Writes”.
DS40001365F-page 27
PIC18(L)F1XK22
3.2
3.2.2
PIC18 Instruction Cycle
3.2.1
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 3-3).
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
instruction register during Q4. The instruction is
decoded and executed during the following Q1 through
Q4. The clocks and instruction execution flow are
shown in Figure 3-3.
FIGURE 3-3:
INSTRUCTION FLOW/PIPELINING
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).
CLOCK/INSTRUCTION CYCLE
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
OSC1
Q1
Q2
Internal
Phase
Clock
Q3
Q4
PC
PC
PC + 2
PC + 4
OSC2/CLKOUT
(RC mode)
Execute INST (PC – 2)
Fetch INST (PC)
EXAMPLE 3-3:
1. MOVLW 55h
4. BSF
Execute INST (PC + 2)
Fetch INST (PC + 4)
INSTRUCTION PIPELINE FLOW
TCY0
TCY1
Fetch 1
Execute 1
2. MOVWF PORTB
3. BRA
Execute INST (PC)
Fetch INST (PC + 2)
SUB_1
PORTA, BIT3 (Forced NOP)
5. Instruction @ address SUB_1
Fetch 2
TCY2
TCY3
TCY4
TCY5
Execute 2
Fetch 3
Execute 3
Fetch 4
Flush (NOP)
Fetch SUB_1 Execute SUB_1
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.
DS40001365F-page 28
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
3.2.3
INSTRUCTIONS IN PROGRAM
MEMORY
The program memory is addressed in bytes.
Instructions are stored as either two bytes or four bytes
in program memory. The Least Significant Byte (LSB)
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 3.1.1 “Program Counter”).
Figure 3-4 shows an example of how instruction words
are stored in the program memory.
FIGURE 3-4:
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,
which accesses the desired byte address in program
memory. Instruction #2 in Figure 3-4 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 24.0 “Instruction Set Summary”
provides further details of the instruction set.
INSTRUCTIONS IN PROGRAM MEMORY
LSB = 1
LSB = 0
0Fh
EFh
F0h
C1h
F4h
55h
03h
00h
23h
56h
Program Memory
Byte Locations
3.2.4
Instruction 1:
Instruction 2:
MOVLW
GOTO
055h
0006h
Instruction 3:
MOVFF
123h, 456h
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 instruction always has
‘1111’ as its four Most Significant bits (MSb); 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
EXAMPLE 3-4:
Word Address
000000h
000002h
000004h
000006h
000008h
00000Ah
00000Ch
00000Eh
000010h
000012h
000014h
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 3-4 shows how this works.
Note:
See Section 3.6 “PIC18 Instruction
Execution and the Extended Instruction Set” for information on two-word
instructions in the extended instruction set.
TWO-WORD INSTRUCTIONS
CASE 1:
Object Code
0110 0110 0000
1100 0001 0010
1111 0100 0101
0010 0100 0000
0000
0011
0110
0000
Source Code
TSTFSZ
REG1
; is RAM location 0?
MOVFF
REG1, REG2 ; No, skip this word
; Execute this word as a NOP
ADDWF
REG3
; continue code
0000
0011
0110
0000
Source Code
TSTFSZ
REG1
; is RAM location 0?
MOVFF
REG1, REG2 ; Yes, execute this word
; 2nd word of instruction
ADDWF
REG3
; continue code
CASE 2:
Object Code
0110 0110 0000
1100 0001 0010
1111 0100 0101
0010 0100 0000
2009-2016 Microchip Technology Inc.
DS40001365F-page 29
PIC18(L)F1XK22
3.3
Note:
Data Memory Organization
The operation of some aspects of data
memory are changed when the PIC18
extended instruction set is enabled. See
Section 3.5 “Data Memory and the
Extended Instruction Set” for more
information.
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. Figure 3-5 and
Figure 3-6 show the data memory organization for the
PIC18(L)F1XK22 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 Bank
Select Register (BSR). Section 3.3.2 “Access Bank”
provides a detailed description of the Access RAM.
3.3.1
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 4 Most Significant bits of a
location’s address; the instruction itself includes the
8 Least Significant bits. Only the four lower bits of the
BSR are implemented (BSR). The upper four bits
are unused; they will always read ‘0’ and cannot be
written to. The BSR can be loaded directly by using the
MOVLB instruction.
The value of the BSR indicates the bank in data
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 3-5 and Figure 3-6.
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 maps in
Figure 3-5 and Figure 3-6 indicate 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.
DS40001365F-page 30
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 3-5:
DATA MEMORY MAP FOR PIC18(L)F13K22 DEVICES
BSR
= 0000
= 0001
= 0010
= 0011
= 0100
= 0101
= 0110
= 0111
= 1000
= 1001
= 1010
= 1011
= 1100
= 1101
= 1110
00h
Access RAM
FFh
00h
GPR
Bank 0
000h
05Fh
060h
0FFh
100h
Bank 1
Bank 2
Bank 3
Bank 4
Bank 5
Bank 6
Bank 7
Bank 8
FFh
00h
1FFh
200h
FFh
00h
2FFh
300h
FFh
00h
3FFh
400h
FFh
00h
4FFh
500h
FFh
00h
5FFh
600h
FFh
00h
6FFh
700h
FFh
00h
Unused
Read 00h
8FFh
900h
FFh
00h
9FFh
A00h
FFh
00h
AFFh
B00h
FFh
00h
BFFh
C00h
FFh
Bank 13 00h
CFFh
D00h
FFh
00h
DFFh
E00h
Bank 9
Bank 10
Bank 11
Bank 12
Bank 14
Unused
SFR(1)
Bank 15
FFh
SFR
The BSR is ignored and the
Access Bank is used.
The first 96 bytes are
general purpose RAM
(from Bank 0).
The second 160 bytes are
Special Function Registers
(from Bank 15).
When ‘a’ = 1:
The BSR specifies the Bank
used by the instruction.
7FFh
800h
FFh
00h
FFh
00h
= 1111
When ‘a’ = 0:
Data Memory Map
Access Bank
Access RAM Low
00h
5Fh
Access RAM High 60h
(SFRs)
FFh
EFFh
F00h
F53h
F5Fh
F60h
FFFh
Note 1: SFRs occupying F53h to F5Fh address space are not in the virtual bank.
2009-2016 Microchip Technology Inc.
DS40001365F-page 31
PIC18(L)F1XK22
FIGURE 3-6:
DATA MEMORY MAP FOR PIC18(L)F14K22 DEVICES
BSR
= 0000
= 0001
= 0010
= 0011
= 0100
= 0101
= 0110
= 0111
= 1000
= 1001
= 1010
= 1011
= 1100
= 1101
= 1110
00h
Access RAM
FFh
00h
GPR
Bank 0
Bank 2
Bank 3
Bank 4
Bank 5
Bank 6
Bank 7
Bank 8
Bank 9
000h
05Fh
060h
0FFh
100h
GPR
Bank 1
FFh
00h
1FFh
200h
FFh
00h
2FFh
300h
FFh
00h
3FFh
400h
FFh
00h
4FFh
500h
FFh
00h
5FFh
600h
FFh
00h
6FFh
700h
FFh
00h
Unused
Read 00h
9FFh
A00h
FFh
00h
AFFh
B00h
FFh
00h
BFFh
C00h
FFh
Bank 13 00h
CFFh
D00h
FFh
00h
DFFh
E00h
Bank 11
Bank 12
Bank 14
Unused
SFR(1)
Bank 15
FFh
The first 96 bytes are
general purpose RAM
(from Bank 0).
The second 160 bytes are
Special Function Registers
(from Bank 15).
When ‘a’ = 1:
The BSR specifies the Bank
used by the instruction.
Access Bank
Access RAM Low
SFR
00h
5Fh
Access RAM High 60h
(SFRs)
FFh
8FFh
900h
FFh
00h
Bank 10
The BSR is ignored and the
Access Bank is used.
7FFh
800h
FFh
00h
FFh
00h
= 1111
When ‘a’ = 0:
Data Memory Map
EFFh
F00h
F53h
F5Fh
F60h
FFFh
Note 1: SFRs occupying F53h to F5Fh address space are not in the virtual bank.
DS40001365F-page 32
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 3-7:
USE OF THE BANK SELECT REGISTER (DIRECT ADDRESSING)
0
Data Memory
BSR(1)
7
0
0
0
0
0
0
1
000h
Bank 0
0
100h
Bank Select(2)
200h
Bank 1
Bank 2
300h
00h
7
FFh
00h
1
From Opcode(2)
1
1
1
1
1
0
1
1
FFh
00h
FFh
00h
Bank 3
through
Bank 13
E00h
F00h
FFFh
Note 1:
2:
Bank 14
Bank 15
FFh
00h
FFh
00h
FFh
The Access RAM bit of the instruction can be used to force an override of the selected bank (BSR) to
the registers of the Access Bank.
The MOVFF instruction embeds the entire 12-bit address in the instruction.
2009-2016 Microchip Technology Inc.
DS40001365F-page 33
PIC18(L)F1XK22
3.3.2
ACCESS BANK
While the use of the BSR with an embedded 8-bit
address allows users to address the entire range of
data memory, it also means that the user must always
ensure that the correct bank is selected. Otherwise,
data may be read from or written to the wrong location.
This can be disastrous if a GPR is the intended target
of an operation, but an SFR is written to instead.
Verifying and/or changing the BSR for each read or
write to data memory can become very inefficient.
To streamline access for the most commonly used data
memory locations, the data memory is configured with
an Access Bank, which allows users to access a
mapped block of memory without specifying a BSR.
The Access Bank consists of the first 96 bytes of
memory (00h-5Fh) in Bank 0 and the last 160 bytes of
memory (60h-FFh) in Block 15. The lower half is known
as the “Access RAM” and is composed of GPRs. This
upper half is also 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 3-5 and Figure 3-6).
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.
3.3.3
GENERAL PURPOSE REGISTER
FILE
PIC18 devices may have banked memory in the GPR
area. This is data RAM, which is available for use by all
instructions. GPRs start at the bottom of Bank 0
(address 000h) and grow upwards towards the bottom of
the SFR area. GPRs are not initialized by a Power-on
Reset and are unchanged on all other Resets.
3.3.4
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 portion of Bank 15 (F60h to FFFh). A list of
these registers is given in Table 3-1 and Table 3-2.
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.
Using this “forced” addressing allows the instruction to
operate on a data address in a single cycle, without
updating the BSR first. For 8-bit addresses of 60h and
above, this means that users can evaluate and operate
on SFRs more efficiently. The Access RAM below 60h
is a good place for data values that the user might need
to access rapidly, such as immediate computational
results or common program variables. Access RAM
also allows for faster and more code efficient context
saving and switching of variables.
The mapping of the Access Bank is slightly different
when the extended instruction set is enabled (XINST
Configuration bit = 1). This is discussed in more detail
in Section 3.5.3 “Mapping the Access Bank in
Indexed Literal Offset Mode”.
DS40001365F-page 34
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 3-1:
Address
FFFh
SPECIAL FUNCTION REGISTER MAP FOR PIC18(L)F1XK22 DEVICES
Name
Address
TOSU
FD7h
Name
TMR0H
Address
FAFh
Name
Address
SPBRG
Name
Address
Name
F87h
—
(2)
F5Fh
—(2)
F5Eh
—(2)
FFEh
TOSH
FD6h
TMR0L
FAEh
RCREG
F86h
—(2)
FFDh
TOSL
FD5h
T0CON
FADh
TXREG
F85h
—(2)
F5Dh
—(2)
F84h
—
(2)
F5Ch
—(2)
F83h
—(2)
F5Bh
—(2)
F82h
PORTC
F5Ah
—(2)
FFCh
FFBh
STKPTR
FD4h
PCLATU
FD3h
(2)
—
OSCCON
FACh
FABh
TXSTA
RCSTA
(2)
FFAh
PCLATH
FD2h
OSCCON2
FAAh
—
FF9h
PCL
FD1h
WDTCON
FA9h
EEADR
F81h
PORTB
F59h
—(2)
FF8h
TBLPTRU
FD0h
RCON
FA8h
EEDATA
F80h
PORTA
F58h
—(2)
F7Fh
ANSELH
F57h
—(2)
FF7h
TBLPTRH
FCFh
TMR1H
FA7h
FF6h
TBLPTRL
FCEh
TMR1L
FA6h
EECON1
F7Eh
ANSEL
F56h
—(2)
FF5h
TABLAT
FCDh
T1CON
FA5h
—(2)
F7Dh
—(2)
F55h
—(2)
FA4h
(2)
F7Ch
—
(2)
F54h
—(2)
—
(2)
F53h
—(2)
FF4h
FF3h
PRODH
FCCh
TMR2
PR2
FA3h
EECON2
(1)
—
(2)
—
F7Bh
PRODL
FCBh
FF2h
INTCON
FCAh
T2CON
FA2h
IPR2
F7Ah
IOCB
FF1h
INTCON2
FC9h
SSPBUF
FA1h
PIR2
F79h
IOCA
FF0h
INTCON3
FC8h
SSPADD
FA0h
PIE2
F78h
WPUB
FEFh
INDF0(1)
FC7h
SSPSTAT
F9Fh
IPR1
F77h
WPUA
FEEh POSTINC0(1)
FC6h
SSPCON1
F9Eh
PIR1
F76h
SLRCON
FEDh POSTDEC0(1)
FC5h
SSPCON2
F9Dh
PIE1
F75h
—(2)
F74h
—(2)
FECh
PREINC0(1)
FC4h
ADRESH
F9Ch
—(2)
FEBh
(1)
FC3h
ADRESL
F9Bh
OSCTUNE
PLUSW0
F73h
—(2)
(2)
FEAh
FSR0H
FC2h
ADCON0
F9Ah
—
F72h
—(2)
FE9h
FSR0L
FC1h
ADCON1
F99h
—(2)
F71h
—(2)
F98h
(2)
FE8h
FE7h
WREG
INDF1
FC0h
(1)
ADCON2
F70h
—(2)
(2)
—
FBFh
CCPR1H
F97h
—
F6Fh
SSPMASK
FE6h POSTINC1(1)
FBEh
CCPR1L
F96h
—(2)
F6Eh
—(2)
FE5h POSTDEC1(1)
FBDh
CCP1CON
F95h
—(2)
F6Dh
CM1CON0
FE4h
PREINC1
(1)
FBCh VREFCON2
F94h
TRISC
F6Ch
CM2CON1
FE3h
PLUSW1(1)
FBBh VREFCON1
F93h
TRISB
F6Bh
CM2CON0
FE2h
FSR1H
FBAh VREFCON0
F92h
TRISA
F6Ah
—(2)
FE1h
FSR1L
FB9h
F91h
—(2)
F69h
SRCON1
PSTRCON
FE0h
BSR
FB8h
BAUDCON
F90h
—(2)
F68h
SRCON0
FDFh
INDF2(1)
FB7h
PWM1CON
F8Fh
—(2)
F67h
—(2)
(2)
(1)
FB6h
ECCP1AS
F8Eh
—
F66h
—(2)
FDDh POSTDEC2(1)
F8Dh
—(2)
F65h
—(2)
F8Ch
(2)
—
F64h
—(2)
FDEh POSTINC2
FDCh
FB5h
—(2)
(1)
FB4h
(2)
(1)
FB3h
TMR3H
F8Bh
LATC
F63h
—(2)
PREINC2
—
FDBh
PLUSW2
FDAh
FSR2H
FB2h
TMR3L
F8Ah
LATB
F62h
—(2)
FD9h
FSR2L
FB1h
T3CON
F89h
LATA
F61h
—(2)
F88h
—(2)
F60h
—(2)
FD8h
Legend:
Note 1:
2:
STATUS
FB0h
SPBRGH
= Unimplemented data memory locations, read as ‘0’,
This is not a physical register.
Unimplemented registers are read as ‘0’.
2009-2016 Microchip Technology Inc.
DS40001365F-page 35
PIC18(L)F1XK22
TABLE 3-2:
File Name
TOSU
REGISTER FILE SUMMARY (PIC18(L)F1XK22)
Bit 7
Bit 6
Bit 5
—
—
—
TOSH
Top-of-Stack, High Byte (TOS)
TOSL
Top-of-Stack, Low Byte (TOS)
STKPTR
PCLATU
STKOVF
STKUNF
—
—
—
—
PCLATH
Holding Register for PC
PCL
PC, Low Byte (PC)
TBLPTRU
—
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Top-of-Stack Upper Byte (TOS)
Value on
POR, BOR
Details
on
page:
---0 0000 245, 25
0000 0000 245, 25
0000 0000 245, 25
SP4
SP3
SP2
SP1
SP0
Holding Register for PC
00-0 0000 245, 26
---0 0000 245, 25
0000 0000 245, 25
0000 0000 245, 25
—
—
Program Memory Table Pointer Upper Byte (TBLPTR)
---0 0000 245, 48
TBLPTRH
Program Memory Table Pointer, High Byte (TBLPTR)
0000 0000 245, 48
TBLPTRL
Program Memory Table Pointer, Low Byte (TBLPTR)
0000 0000 245, 48
TABLAT
Program Memory Table Latch
0000 0000 245, 48
PRODH
Product Register, High Byte
xxxx xxxx 245, 58
PRODL
Product Register, Low Byte
xxxx xxxx 245, 58
INTCON
GIE/GIEH
PEIE/GIEL
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
0000 000x 245, 62
INTCON2
RABPU
INTEDG0
INTEDG1
INTEDG2
—
TMR0IP
—
RABIP
1111 -1-1 245, 63
INT2IP
INT1IP
—
INT2IE
INT1IE
—
INT2IF
INT1IF
11-0 0-00 245, 64
INTCON3
INDF0
Uses contents of FSR0 to address data memory – value of FSR0 not changed (not a physical register)
N/A
245, 41
POSTINC0
Uses contents of FSR0 to address data memory – value of FSR0 post-incremented (not a physical register)
N/A
245, 41
POSTDEC0 Uses contents of FSR0 to address data memory – value of FSR0 post-decremented (not a physical register)
N/A
245, 41
PREINC0
Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register)
N/A
245, 41
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
245, 41
FSR0H
—
—
—
—
Indirect Data Memory Address Pointer 0, High Byte
---- 0000 245, 41
FSR0L
Indirect Data Memory Address Pointer 0, Low Byte
xxxx xxxx 245, 41
WREG
Working Register
xxxx xxxx 245
INDF1
Uses contents of FSR1 to address data memory – value of FSR1 not changed (not a physical register)
N/A
245, 41
POSTINC1
Uses contents of FSR1 to address data memory – value of FSR1 post-incremented (not a physical register)
N/A
245, 41
POSTDEC1 Uses contents of FSR1 to address data memory – value of FSR1 post-decremented (not a physical register)
N/A
245, 41
PREINC1
Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register)
N/A
245, 41
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
245, 41
FSR1H
—
FSR1L
—
—
—
Indirect Data Memory Address Pointer 1, High Byte
---- 0000 246, 41
Bank Select Register
---- 0000 246, 30
Indirect Data Memory Address Pointer 1, Low Byte
BSR
—
—
—
—
xxxx xxxx 246, 41
INDF2
Uses contents of FSR2 to address data memory – value of FSR2 not changed (not a physical register)
N/A
246, 41
POSTINC2
Uses contents of FSR2 to address data memory – value of FSR2 post-incremented (not a physical register)
N/A
246, 41
POSTDEC2 Uses contents of FSR2 to address data memory – value of FSR2 post-decremented (not a physical register)
N/A
246, 41
PREINC2
Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register)
N/A
246, 41
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
246, 41
FSR2H
—
FSR2L
—
—
—
Indirect Data Memory Address Pointer 2, High Byte
---- 0000 246, 41
Indirect Data Memory Address Pointer 2, Low Byte
STATUS
Legend:
Note 1:
2:
3:
—
—
—
N
xxxx xxxx 246, 41
OV
Z
DC
C
---x xxxx 246, 39
x = unknown, u = unchanged, — = unimplemented, q = value depends on condition
The SBOREN bit is only available when the BOREN Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See
Section 22.4 “Brown-out Reset (BOR)”.
The RA3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0). Otherwise, RA3 reads as ‘0’. This bit is
read-only.
Unimplemented, read as ‘1’.
DS40001365F-page 36
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 3-2:
File Name
REGISTER FILE SUMMARY (PIC18(L)F1XK22) (CONTINUED)
Bit 7
Bit 6
TMR0H
Timer0 Register, High Byte
TMR0L
Timer0 Register, Low Byte
T0CON
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Details
on
page:
0000 0000 246, 92
xxxx xxxx 246, 92
TMR0ON
T08BIT
T0CS
T0SE
PSA
T0PS2
T0PS1
T0PS0
OSCCON
IDLEN
IRCF2
IRCF1
IRCF0
OSTS
HFIOFS
SCS1
SCS0
0011 qq00 246, 17
OSCCON2
—
—
—
—
—
PRI_SD
HFIOFL
LFIOFS
---- -10x 246, 18
WDTCON
—
—
—
—
—
—
—
SWDTEN
IPEN
SBOREN(1)
—
RI
TO
PD
POR
BOR
RCON
1111 1111 246, 91
--- ---0 246, 260
0q-1 11q0
237,
246, 71
TMR1H
Timer1 Register, High Byte
xxxx xxxx 246, 94
TMR1L
Timer1 Register, Low Bytes
xxxx xxxx 246, 94
T1CON
RD16
T1RUN
TMR2
Timer2 Register
PR2
Timer2 Period Register
T2CON
—
T1CKPS1
T1CKPS0
T1OSCEN
T1SYNC
TMR1CS
TMR1ON
0000 0000 246, 94
0000 0000 246, 100
T2OUTPS3
1111 1111 246, 100
T2OUTPS2
T2OUTPS1
T2OUTPS0
TMR2ON
T2CKPS1
T2CKPS0
-000 0000 246, 100
246,
128, 130
SSPBUF
SSP Receive Buffer/Transmit Register
xxxx xxxx
SSPADD
SSP Address Register in I2C Slave Mode. SSP Baud Rate Reload Register in I2C Master Mode.
0000 0000 246, 147
246,
128, 137
SSPSTAT
SMP
CKE
D/A
P
S
R/W
UA
BF
SSPCON1
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
0000 0000 246,
128, 138
GCEN
ACKSTAT
ACKDT
ACKEN
RCEN
PEN
RSEN
SEN
0000 0000 246, 139
SSPCON2
ADRESH
A/D Result Register, High Byte
ADRESL
A/D Result Register, Low Byte
—
—
ADCON1
—
—
ADCON2
ADFM
—
ADCON0
xxxx xxxx 247, 197
xxxx xxxx 247, 197
CHS3
CHS2
CHS1
CHS0
GO/DONE
ADON
—
—
PVCFG1
PVCFG0
NVCFG1
NVCFG0
---- 0000 247, 204
ACQT2
ACQT1
ACQT0
ADCS2
ADCS1
ADCS0
0-00 0000 247, 205
CCPR1H
Capture/Compare/PWM Register 1, High Byte
CCPR1L
Capture/Compare/PWM Register 1, Low Byte
CCP1CON
P1M1
P1M0
DC1B1
VREFCON2
—
—
—
DAC1OE
VREFCON1
D1EN
D1LPS
VREFCON0
FVR1EN
FVR1ST
0000 0000
--00 0000 247, 203
xxxx xxxx 247, 126
xxxx xxxx 247, 126
DC1B0
CCP1M3
CCP1M2
CCP1M1
CCP1M0
DAC1R
---
FVR1S
0000 0000 247, 106
---0 0000 247, 236
—
D1NSS
000- 00-0 247, 235
—
—
—
—
0001 ---- 247, 232
D1PSS
PSTRCON
—
—
—
STRSYNC
STRD
STRC
STRB
STRA
---0 0001 247, 123
BAUDCON
ABDOVF
RCIDL
DTRXP
CKTXP
BRG16
—
WUE
ABDEN
0100 0-00 247, 181
PWM1CON
PRSEN
PDC6
PDC5
PDC4
PDC3
PDC2
PDC1
PDC0
0000 0000 247, 122
ECCP1AS
ECCPASE
ECCPAS2
ECCPAS1
ECCPAS0
PSSAC1
PSSAC0
PSSBD1
PSSBD0
0000 0000 247, 118
TMR3H
Timer3 Register, High Byte
xxxx xxxx 247, 102
TMR3L
Timer3 Register, Low Byte
xxxx xxxx 247, 102
RD16
T3CON
Legend:
Note 1:
2:
3:
—
T3CKPS1
T3CKPS0
T3CCP1
T3SYNC
TMR3CS
TMR3ON
0-00 0000 247, 102
x = unknown, u = unchanged, — = unimplemented, q = value depends on condition
The SBOREN bit is only available when the BOREN Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See
Section 22.4 “Brown-out Reset (BOR)”.
The RA3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0). Otherwise, RA3 reads as ‘0’. This bit is
read-only.
Unimplemented, read as ‘1’.
2009-2016 Microchip Technology Inc.
DS40001365F-page 37
PIC18(L)F1XK22
TABLE 3-2:
File Name
REGISTER FILE SUMMARY (PIC18(L)F1XK22) (CONTINUED)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Details
on
page:
SPBRGH
EUSART Baud Rate Generator Register, High Byte
0000 0000 247, 182
SPBRG
EUSART Baud Rate Generator Register, Low Byte
0000 0000 247, 182
RCREG
EUSART Receive Register
0000 0000 247, 175
TXREG
EUSART Transmit Register
0000 0000 247, 172
TXSTA
CSRC
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
0000 0010 247, 179
RCSTA
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
0000 000x 247, 180
EEADR
EEADR7
EEADR6
EEADR5
EEADR4
EEADR3
EEADR2
EEADR1
EEADR0
0000 0000
247, 45,
54
EEDATA
EEPROM Data Register
0000 0000
247, 45,
54
EECON2
EEPROM Control Register 2 (not a physical register)
0000 0000
247, 45,
54
247, 45,
54
EECON1
EEPGD
CFGS
—
FREE
WRERR
WREN
WR
RD
xx-0 x000
IPR2
OSCFIP
C1IP
C2IP
EEIP
BCLIP
—
TMR3IP
—
1111 1-1- 248, 70
PIR2
OSCFIF
C1IF
C2IF
EEIF
BCLIF
—
TMR3IF
—
0000 0-0- 248, 66
PIE2
OSCFIE
C1IE
C2IE
EEIE
BCLIE
—
TMR3IE
—
0000 0-0- 248, 68
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
-111 1111 248, 69
PIR1
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
-000 0000 248, 65
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
-000 0000 248, 67
OSCTUNE
INTSRC
PLLEN
TUN5
TUN4
TUN3
TUN2
TUN1
TUN0
0000 0000 248, 19
TRISC
TRISC7
TRISC6
TRISC5
TRISC4
TRISC3
TRISC2
TRISC1
TRISC0
1111 1111 248, 84
TRISB
TRISB7
TRISB6
TRISB5
TRISB4
—
—
—
—
1111 ---- 248, 80
TRISA
—
—
TRISA5
TRISA4
—(3)
TRISA2
TRISA1
TRISA0
--11 1111 248, 75
LATC
LATC7
LATC6
LATC5
LATC4
LATC3
LATC2
LATC1
LATC0
xxxx xxxx 248, 85
LATB
LATB7
LATB6
LATB5
LATB4
—
—
—
—
xxxx ---- 248, 80
LATA
—
—
LATA5
LATA4
—
LATA2
LATA1
LATA0
--xx -xxx 248, 76
PORTC
RC7
RC6
RC5
RC4
RC3
RC2
RC1
RC0
xxxx xxxx 248, 84
PORTB
RB7
RB6
RB5
RB4
—
—
—
—
xxxx ---- 248, 80
PORTA
—
—
RA5
RA4
RA3(2)
RA2
RA1
RA0
--xx xxxx 248, 75
ANSELH
—
—
—
—
ANS11
ANS10
ANS9
ANS8
---- 1111 248, 89
ANSEL
ANS7
ANS6
ANS5
ANS4
ANS3
ANS2
ANS1
ANS0
1111 1111 248, 88
IOCB
IOCB7
IOCB6
IOCB5
IOCB4
—
—
—
—
0000 ---- 248, 81
IOCA
—
—
IOCA5
IOCA4
IOCA3
IOCA2
IOCA1
IOCA0
--00 0000 248, 76
WPUB
WPUB7
WPUB6
WPUB5
WPUB4
—
—
—
—
1111 ---- 248, 81
WPUA
—
—
WPUA5
WPUA4
WPUA3
WPUA2
WPUA1
WPUA0
--11 1111 245, 76
SLRCON
—
—
—
—
—
SLRC
SLRB
SLRA
---- -111 248, 90
SSPMSK
MSK7
MSK6
MSK5
MSK4
MSK3
MSK2
MSK1
MSK0
1111 1111 248, 146
CM1CON0
C1ON
C1OUT
C1OE
C1POL
C1SP
C1R
C1CH1
C1CH0
0000 0000 248, 216
CM2CON1
MC1OUT
MC2OUT
C1RSEL
C2RSEL
C1HYS
C2HYS
C1SYNC
C2SYNC
0000 0000 248, 220
CM2CON0
C2ON
C2OUT
C2OE
C2POL
C2SP
C2R
C2CH1
C2CH0
0000 0000 248, 217
SRCON1
SRSPE
SRSCKE
SRSC2E
SRSC1E
SRRPE
SRRCKE
SRRC2E
SRRC1E
0000 0000 248, 230
SRCON0
SRLEN
SRCLK2
SRCLK1
SRCLK0
SRQEN
SRNQEN
SRPS
SRPR
0000 0000 248, 229
Legend:
Note 1:
2:
3:
x = unknown, u = unchanged, — = unimplemented, q = value depends on condition
The SBOREN bit is only available when the BOREN Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See
Section 22.4 “Brown-out Reset (BOR)”.
The RA3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0). Otherwise, RA3 reads as ‘0’. This bit is
read-only.
Unimplemented, read as ‘1’.
DS40001365F-page 38
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
3.3.5
STATUS REGISTER
The STATUS register, shown in Register 3-2, 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
instruction that affects the Z, DC, C, OV or N bits, the
results of the instruction are not written; instead, the
STATUS register is updated according to the
instruction 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’).
REGISTER 3-2:
It is recommended that only BCF, BSF, SWAPF, MOVFF
and MOVWF instructions are used to alter the STATUS
register, because these instructions do not affect the Z,
C, DC, OV or N bits in the STATUS register.
For other instructions that do not affect Status bits, see
the instruction set summaries in Table 24-2 and
Table 24-3.
Note:
The C and DC bits operate as the borrow
and digit borrow bits, respectively, in
subtraction.
STATUS: STATUS REGISTER
U-0
U-0
U-0
—
—
—
R/W-x
N
R/W-x
OV
R/W-x
R/W-x
R/W-x
(1)
Z
DC
bit 7
C(1)
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 (two’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 (two’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 (ADDWF, ADDLW,SUBLW,SUBWF instructions)(1)
1 = A carry-out from the 4th low-order bit of the result occurred
0 = No carry-out from the 4th low-order bit of the result
bit 0
C: Carry/Borrow bit (ADDWF, ADDLW, SUBLW, SUBWF instructions)(1)
1 = A carry-out from the Most Significant bit of the result occurred
0 = No carry-out from the Most Significant bit of the result occurred
Note 1:
For Borrow, the polarity is reversed. A subtraction is executed by adding the two’s complement of the
second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high-order or low-order
bit of the source register.
2009-2016 Microchip Technology Inc.
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PIC18(L)F1XK22
3.4
Data Addressing Modes
Note:
The execution of some instructions in the
core PIC18 instruction set are changed
when the PIC18 extended instruction set is
enabled. See Section 3.5 “Data Memory
and the Extended Instruction Set” for
more information.
While the program memory can be addressed in only
one way – through the program counter – information
in the data memory space can be addressed in several
ways. For most instructions, the addressing mode is
fixed. Other instructions may use up to three modes,
depending on which operands are used and whether or
not the extended instruction set is enabled.
The addressing modes are:
•
•
•
•
Inherent
Literal
Direct
Indirect
An additional addressing mode, Indexed Literal Offset,
is available when the extended instruction set is
enabled (XINST Configuration bit = 1). Its operation is
discussed in greater detail in Section 3.5.1 “Indexed
Addressing with Literal Offset”.
3.4.1
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.
3.4.2
Purpose Register File”) or a location in the Access
Bank (Section 3.3.2 “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 3.3.1 “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.
3.4.3
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 which are to be read
or written. Since the FSRs are themselves located in
RAM as Special File 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 3-5.
EXAMPLE 3-5:
DIRECT ADDRESSING
LFSR
CLRF
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.
NEXT
In the core PIC18 instruction set, bit-oriented and byteoriented 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 3.3.3 “General
BRA
CONTINUE
DS40001365F-page 40
BTFSS
HOW TO CLEAR RAM
(BANK 1) USING
INDIRECT ADDRESSING
FSR0, 100h ;
POSTINC0
; Clear INDF
; register then
; inc pointer
FSR0H, 1
; All done with
; Bank1?
NEXT
; NO, clear next
; YES, continue
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
3.4.3.1
FSR Registers and the INDF
Operand
3.4.3.2
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. Each FSR
pair holds a 12-bit value, therefore the four upper bits
of the FSRnH register are not used. The 12-bit FSR
value 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.
In addition to the INDF operand, each FSR register pair
also has four additional indirect operands. Like INDF,
these are “virtual” registers which cannot be directly
read or written. Accessing these registers actually
accesses the location to which the associated FSR
register pair points, and also performs a specific action
on the FSR value. They are:
• POSTDEC: accesses the location to which the
FSR points, then automatically decrements the
FSR by 1 afterwards
• POSTINC: accesses the location to which the
FSR points, then automatically increments the
FSR by 1 afterwards
• PREINC: automatically increments the FSR by 1,
then uses the location to which the FSR points 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 location to which the result points in the
operation.
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
register actually accesses its corresponding FSR
register pair. A read from INDF1, for example, reads
the data at the address indicated by FSR1H:FSR1L.
Instructions that use the INDF registers as operands
actually use the contents of their corresponding FSR as
a pointer to the 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.
FIGURE 3-8:
FSR Registers and POSTINC,
POSTDEC, PREINC and PLUSW
In this context, accessing an INDF register uses the
value in the associated FSR register without changing
it. Similarly, accessing a PLUSW register gives the
FSR value an offset by that in the W register; however,
neither W nor the FSR is actually changed in the
operation. Accessing the other virtual registers
changes the value of the FSR register.
INDIRECT ADDRESSING
000h
Using an instruction with one of the
indirect addressing registers as the
operand....
Bank 0
ADDWF, INDF1, 1
100h
Bank 1
200h
...uses the 12-bit address stored in
the FSR pair associated with that
register....
300h
FSR1H:FSR1L
7
0
x x x x 1 1 1 0
7
0
Bank 2
Bank 3
through
Bank 13
1 1 0 0 1 1 0 0
...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.
E00h
Bank 14
F00h
FFFh
Bank 15
Data Memory
2009-2016 Microchip Technology Inc.
DS40001365F-page 41
PIC18(L)F1XK22
Operations on the FSRs with POSTDEC, POSTINC
and PREINC affect the entire register pair; that is,
rollovers of the FSRnL register from FFh to 00h carry
over to the FSRnH register. On the other hand, results
of these operations do not change the value of any
flags in the STATUS register (e.g., Z, N, OV, etc.).
The PLUSW register can be used to implement a form
of indexed addressing in the data memory space. By
manipulating the value in the W register, users can
reach addresses that are fixed offsets from pointer
addresses. In some applications, this can be used to
implement some powerful program control structure,
such as software stacks, inside of data memory.
3.4.3.3
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 either
the INDF2 or POSTDEC2 register 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 generally
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.
3.5
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.
3.5.1
INDEXED ADDRESSING WITH
LITERAL OFFSET
Enabling the PIC18 extended instruction set changes
the behavior of indirect addressing using the FSR2
register pair within Access RAM. Under the proper
conditions, instructions that use the Access Bank – that
is, most bit-oriented and byte-oriented instructions –
can invoke a form of indexed addressing using an
offset specified in the instruction. This special
addressing mode is known as Indexed Addressing with
Literal Offset, or Indexed Literal Offset mode.
When using the extended instruction set, this
addressing mode requires the following:
• The use of the Access Bank is forced (‘a’ = 0) and
• The file address argument is less than or equal to
5Fh.
Under these conditions, the file address of the
instruction is not interpreted as the lower byte of an
address (used with the BSR in direct addressing), or as
an 8-bit address in the Access Bank. Instead, the value
is interpreted as an offset value to an Address Pointer,
specified by FSR2. The offset and the contents of
FSR2 are added to obtain the target address of the
operation.
3.5.2
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 3-9.
Those who desire to use byte-oriented or bit-oriented
instructions in the Indexed Literal Offset mode should
note the changes to assembler syntax for this mode.
This is described in more detail in Section 24.2.1
“Extended Instruction Syntax”.
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 remain unchanged.
DS40001365F-page 42
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 3-9:
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 F60h to FFFh
(Bank 15) of data memory.
Locations below 60h are not
available in this addressing
mode.
000h
060h
Bank 0
100h
00h
Bank 1
through
Bank 14
F00h
60h
Valid range
for ‘f’
Access RAM
FFh
Bank 15
F60h
SFRs
FFFh
Data Memory
When ‘a’ = 0 and f5Fh:
The instruction executes in
Indexed Literal Offset mode. ‘f’
is interpreted as an offset to the
address value in FSR2. The
two are added together to
obtain the address of the target
register for the instruction. The
address can be anywhere in
the data memory space.
Note that in this mode, the
correct syntax is now:
ADDWF [k], d
where ‘k’ is the same as ‘f’.
000h
060h
Bank 0
100h
001001da ffffffff
Bank 1
through
Bank 14
FSR2H
FSR2L
F00h
Bank 15
F60h
SFRs
FFFh
Data Memory
When ‘a’ = 1 (all values of f):
The instruction executes in
Direct mode (also known as
Direct Long mode). ‘f’ is
interpreted as a location in
one of the 16 banks of the data
memory space. The bank is
designated by the Bank Select
Register (BSR). The address
can be in any implemented
bank in the data memory
space.
BSR
00000000
000h
060h
Bank 0
100h
Bank 1
through
Bank 14
001001da ffffffff
F00h
Bank 15
F60h
SFRs
FFFh
Data Memory
2009-2016 Microchip Technology Inc.
DS40001365F-page 43
PIC18(L)F1XK22
3.5.3
MAPPING THE ACCESS BANK IN
INDEXED LITERAL OFFSET 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 section of Bank 0, this
mode maps the contents from 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 3.3.2
“Access Bank”). An example of Access Bank
remapping in this addressing mode is shown in
Figure 3-10.
FIGURE 3-10:
Remapping of the Access Bank applies only to
operations using the Indexed Literal Offset mode.
Operations that use the BSR (Access RAM bit is ‘1’) will
continue to use direct addressing as before.
3.6
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 24.2 “Extended Instruction Set”.
REMAPPING THE ACCESS BANK WITH INDEXED LITERAL OFFSET
ADDRESSING
Example Situation:
ADDWF f, d, a
FSR2H:FSR2L = 120h
Locations in the region
from the FSR2 pointer
(120h) to the pointer plus
05Fh (17Fh) are mapped
to the bottom of the
Access RAM (000h-05Fh).
000h
Bank 0
100h
120h
17Fh
200h
Bank 1
Window
Bank 1
00h
Bank 1 “Window”
5Fh
60h
Special File Registers at
F60h through FFFh are
mapped to 60h through
FFh, as usual.
Bank 2
through
Bank 14
Bank 0 addresses below
5Fh can still be addressed
by using the BSR.
SFRs
FFh
Access Bank
F00h
Bank 15
F60h
FFFh
SFRs
Data Memory
DS40001365F-page 44
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
4.0
FLASH PROGRAM MEMORY
4.1
Table Reads and Table Writes
The Flash program memory is readable, writable and
erasable during normal operation over the entire VDD
range.
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:
A read from program memory is executed one byte at
a time. A write to program memory is executed on
blocks of 16 or 8 bytes at a time depending on the
specific device (See Table 4-1). Program memory is
erased in blocks of 64 bytes at a time. The difference
between the write and erase block sizes requires from
4 to 8 block writes to restore the contents of a single
block erase. A Bulk Erase operation can not be issued
from user code.
• Table Read (TBLRD)
• Table Write (TBLWT)
TABLE 4-1:
WRITE/ERASE BLOCK SIZES
Write Block
Size (bytes)
Erase Block
Size (bytes)
PIC18(L)F13K22
8
64
PIC18(L)F14K22
16
64
Device
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.
FIGURE 4-1:
The program memory space is 16-bit wide, while the
data RAM space is 8-bit wide. Table reads and table
writes move data between these two memory spaces
through an 8-bit register (TABLAT).
The table read operation retrieves one byte of data
directly from program memory and places it into the
TABLAT register. Figure 4-1 shows the operation of a
table read.
The table write operation stores one byte of data from the
TABLAT register into a write block holding register. The
procedure to write the contents of the holding registers
into program memory is detailed in Section 4.5 “Writing
to Flash Program Memory”. Figure 4-2 shows the
operation of a table write with program memory and data
RAM.
Table operations work with byte entities. Tables
containing data, rather than program instructions, are
not required to be word-aligned. Therefore, a table 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.
TABLE READ OPERATION
Instruction: TBLRD*
Program Memory
Table Pointer(1)
TBLPTRU
TBLPTRH
Table Latch (8-bit)
TBLPTRL
TABLAT
Program Memory
(TBLPTR)
Note 1: Table Pointer register points to a byte in program memory.
2009-2016 Microchip Technology Inc.
DS40001365F-page 45
PIC18(L)F1XK22
FIGURE 4-2:
TABLE WRITE OPERATION
Instruction: TBLWT*
Program Memory
Table Pointer(1)
TBLPTRU
TBLPTRH
Holding Registers
Table Latch (8-bit)
TBLPTRL
TABLAT
Program Memory
(TBLPTR)
Note 1: During table writes the Table Pointer does not point directly to Program Memory. The LSBs of TBLPRTL
actually point to an address within the write block holding registers. The MSBs of the Table Pointer
determine where the write block will eventually be written. The process for writing the holding registers
to the program memory array is discussed in Section 4.5 “Writing to Flash Program Memory”.
4.2
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
4.2.1
EECON1 AND EECON2 REGISTERS
The EECON1 register (Register 4-1) is the control
register for memory accesses. The EECON2 register is
not a physical register; it is used exclusively in the
memory write and erase sequences. Reading
EECON2 will read all ‘0’s.
The EEPGD control bit determines if the access will be
a program or data EEPROM memory access. When
EEPGD is clear, any subsequent operations will
operate on the data EEPROM memory. When EEPGD
is 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 CFGS is set,
subsequent operations will operate on Configuration
registers regardless of EEPGD (see Section 23.0
“Special Features of the CPU”). When CFGS is clear,
memory selection access is determined by EEPGD.
DS40001365F-page 46
The FREE bit allows the program memory erase
operation. When FREE is set, an 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.
The WREN bit is clear on power-up.
The WRERR bit is set by hardware when the WR bit is
set and cleared when the internal programming timer
expires and the write operation is complete.
Note:
During normal operation, the WRERR is
read as ‘1’. This can indicate that a write
operation was prematurely terminated by
a Reset, or a write operation was
attempted improperly.
The WR control bit initiates write operations. The WR
bit cannot be cleared, only set, by firmware. Then WR
bit is cleared by hardware at the completion of the write
operation.
Note:
The EEIF interrupt flag bit of the PIR2
register is set when the write is complete.
The EEIF flag stays set until cleared by
firmware.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 4-1:
EECON1: DATA EEPROM CONTROL 1 REGISTER
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
WREN
WR
RD
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
S = Bit can be set by software, but not cleared
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘0’ = Bit is cleared
‘1’ = Bit is set
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 (Block) Erase Enable bit
1 = Erase the program memory block 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) by 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 by hardware. The RD bit can only
be set (not cleared) by 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.
2009-2016 Microchip Technology Inc.
DS40001365F-page 47
PIC18(L)F1XK22
4.2.2
TABLAT – TABLE LATCH REGISTER
4.2.4
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.
4.2.3
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
directly into the TABLAT register.
TBLPTR – TABLE POINTER
REGISTER
When a TBLWT is executed the byte in the TABLAT
register is written, not to Flash memory but, to a holding
register in preparation for a program memory write. The
holding registers constitute a write block which varies
depending on the device (See Table 4-1).The 3, 4, or 5
LSbs of the TBLPTRL register determine which specific
address within the holding register block is written to.
The MSBs of the Table Pointer have no effect during
TBLWT operations.
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 loworder 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.
When a program memory write is executed the entire
holding register block is written to the Flash memory at
the address determined by the MSbs of the TBLPTR.
The 3, 4, or 5 LSBs are ignored during Flash memory
writes. For more detail, see Section 4.5 “Writing to
Flash Program Memory”.
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 4-2. These operations on the TBLPTR affect only
the low-order 21 bits.
When an erase of program memory is executed, the
16 MSbs of the Table Pointer register (TBLPTR)
point to the 64-byte block that will be erased. The Least
Significant bits (TBLPTR) are ignored.
Figure 4-3 describes the relevant boundaries of
TBLPTR based on Flash program memory operations.
TABLE 4-2:
TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS
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
FIGURE 4-3:
21
TABLE POINTER BOUNDARIES BASED ON OPERATION
TBLPTRU
16
15
TBLPTRH
8
TBLPTRL
7
0
TABLE WRITE
TBLPTR(1)
TABLE ERASE/WRITE
TBLPTR(1)
TABLE READ – TBLPTR
Note 1: n = 3, 4, 5, or 6 for block sizes of 8, 16, 32 or 64 bytes, respectively.
DS40001365F-page 48
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
4.3
Reading the Flash Program
Memory
The TBLRD instruction retrieves data from program
memory and places it into data RAM. Table reads from
program memory are performed one byte at a time.
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 4-4
shows the interface between the internal program
memory and the TABLAT.
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.
FIGURE 4-4:
READS FROM FLASH PROGRAM MEMORY
Program Memory
(Even Byte Address)
(Odd Byte Address)
TBLPTR = xxxxx1
Instruction Register
(IR)
EXAMPLE 4-1:
FETCH
TBLRD
TBLPTR = xxxxx0
TABLAT
Read Register
READING A FLASH PROGRAM MEMORY WORD
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
; Load TBLPTR with the base
; address of the word
READ_WORD
TBLRD*+
MOVF
MOVWF
TBLRD*+
MOVFW
MOVF
TABLAT, W
WORD_EVEN
TABLAT, W
WORD_ODD
2009-2016 Microchip Technology Inc.
; read into TABLAT and increment
; get data
; read into TABLAT and increment
; get data
DS40001365F-page 49
PIC18(L)F1XK22
4.4
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
Microcontroller itself, a block of 64 bytes of program
memory is erased. The Most Significant 16 bits of the
TBLPTR point to the block being erased. The
TBLPTR bits 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.
The write initiate sequence for EECON2, shown as
steps 4 through 6 in Section 4.4.1 “Flash Program
Memory Erase Sequence”, is used to guard against
accidental writes. This is sometimes referred to as a
long write.
4.4.1
FLASH PROGRAM MEMORY
ERASE SEQUENCE
The sequence of events for erasing a block of internal
program memory is:
1.
2.
3.
4.
5.
6.
7.
8.
Load Table Pointer register with address of
block being erased.
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.
Disable interrupts.
Write 55h to EECON2.
Write 0AAh to EECON2.
Set the WR bit. This will begin the block erase
cycle.
The CPU will stall for duration of the erase
(about 2 ms using internal timer).
Re-enable interrupts.
A long write is necessary for erasing the internal
Flash. Instruction execution is halted during the long
write cycle. The long write is terminated by the internal
programming timer.
EXAMPLE 4-2:
ERASING A FLASH PROGRAM MEMORY BLOCK
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
; load TBLPTR with the base
; address of the memory block
BSF
BCF
BSF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BSF
EECON1,
EECON1,
EECON1,
EECON1,
INTCON,
55h
EECON2
0AAh
EECON2
EECON1,
INTCON,
;
;
;
;
;
ERASE_BLOCK
Required
Sequence
DS40001365F-page 50
EEPGD
CFGS
WREN
FREE
GIE
point to Flash program memory
access Flash program memory
enable write to memory
enable block Erase operation
disable interrupts
; write 55h
WR
GIE
; write 0AAh
; start erase (CPU stall)
; re-enable interrupts
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
4.5
Writing to Flash Program Memory
The programming block size is 8 or 16 bytes,
depending on the device (See Table 4-1). 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 only as many holding registers as there are bytes
in a write block (See Table 4-1).
Since the Table Latch (TABLAT) is only a single byte,
the TBLWT instruction may need to be executed 8, or 16
times, depending on the device, for each programming
operation. All of the table write operations will
essentially be short writes because only the holding
registers are written. After all the holding registers have
been written, the programming operation of that block
of memory is started by configuring the EECON1
register for a program memory write and performing the
long write sequence.
FIGURE 4-5:
The long write is necessary for programming the
internal Flash. Instruction execution is halted during 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.
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 holding registers
before executing a long write operation.
TABLE WRITES TO FLASH PROGRAM MEMORY
TABLAT
Write Register
8
8
TBLPTR = xxxx00
TBLPTR = xxxx01
Holding Register
8
TBLPTR = xxxxYY(1)
TBLPTR = xxxx02
Holding Register
8
Holding Register
Holding Register
Program Memory
Note 1: YY = x7 or xF for 8 or 16 byte write blocks, respectively.
4.5.1
FLASH PROGRAM MEMORY WRITE
SEQUENCE
The sequence of events for programming an internal
program memory location should be:
1.
2.
3.
4.
5.
6.
7.
Read 64 bytes into RAM.
Update data values in RAM as necessary.
Load Table Pointer register with address being
erased.
Execute the block erase procedure.
Load Table Pointer register with address of first
byte being written.
Write the 8 or 16 byte block into the holding
registers with auto-increment.
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.
2009-2016 Microchip Technology Inc.
8.
9.
10.
11.
12.
Disable interrupts.
Write 55h to EECON2.
Write 0AAh to EECON2.
Set the WR bit. This will begin the write cycle.
The CPU will stall for duration of the write (about
2 ms using internal timer).
13. Re-enable interrupts.
14. Repeat steps 6 to 13 for each block until all 64
bytes are written.
15. Verify the memory (table read).
This procedure will require about 6 ms to update each
write block of memory. An example of the required code
is given in Example 4-3.
Note:
Before setting the WR bit, the Table
Pointer address needs to be within the
intended address range of the bytes in the
holding registers.
DS40001365F-page 51
PIC18(L)F1XK22
EXAMPLE 4-3:
WRITING TO FLASH PROGRAM MEMORY
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
D'64’
COUNTER
BUFFER_ADDR_HIGH
FSR0H
BUFFER_ADDR_LOW
FSR0L
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
; number of bytes in erase block
TBLRD*+
MOVF
MOVWF
DECFSZ
BRA
TABLAT, W
POSTINC0
COUNTER
READ_BLOCK
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
BUFFER_ADDR_HIGH
FSR0H
BUFFER_ADDR_LOW
FSR0L
NEW_DATA_LOW
POSTINC0
NEW_DATA_HIGH
INDF0
; point to buffer
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BCF
BSF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BSF
TBLRD*MOVLW
MOVWF
MOVLW
MOVWF
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
EECON1, EEPGD
EECON1, CFGS
EECON1, WREN
EECON1, FREE
INTCON, GIE
55h
EECON2
0AAh
EECON2
EECON1, WR
INTCON, GIE
; load TBLPTR with the base
; address of the memory block
MOVLW
MOVWF
MOVLW
MOVWF
BlockSize
COUNTER
D’64’/BlockSize
COUNTER2
MOVF
MOVWF
TBLWT+*
POSTINC0, W
TABLAT
; point to buffer
; Load TBLPTR with the base
; address of the memory block
READ_BLOCK
;
;
;
;
;
read into TABLAT, and inc
get data
store data
done?
repeat
MODIFY_WORD
; update buffer word
ERASE_BLOCK
Required
Sequence
BUFFER_ADDR_HIGH
FSR0H
BUFFER_ADDR_LOW
FSR0L
;
;
;
;
;
point to Flash program memory
access Flash program memory
enable write to memory
enable Erase operation
disable interrupts
; write 55h
;
;
;
;
;
write 0AAh
start erase (CPU stall)
re-enable interrupts
dummy read decrement
point to buffer
WRITE_BUFFER_BACK
; number of bytes in holding register
; number of write blocks in 64 bytes
WRITE_BYTE_TO_HREGS
DS40001365F-page 52
;
;
;
;
get low byte of buffer data
present data to table latch
write data, perform a short write
to internal TBLWT holding register.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
EXAMPLE 4-3:
WRITING TO FLASH PROGRAM MEMORY (CONTINUED)
DECFSZ
BRA
COUNTER
WRITE_WORD_TO_HREGS
; loop until holding registers are full
BSF
BCF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
DCFSZ
BRA
BSF
BCF
EECON1, EEPGD
EECON1, CFGS
EECON1, WREN
INTCON, GIE
55h
EECON2
0AAh
EECON2
EECON1, WR
COUNTER2
WRITE_BYTE_TO_HREGS
INTCON, GIE
EECON1, WREN
;
;
;
;
PROGRAM_MEMORY
Required
Sequence
4.5.2
WRITE VERIFY
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 WRERR bit will be set
which the user can check to decide whether a rewrite
of the location(s) is needed.
TABLE 4-3:
Name
EECON1
; write 55h
;
;
;
;
;
;
write 0AAh
start program (CPU stall)
repeat for remaining write blocks
re-enable interrupts
disable write to memory
4.5.4
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.
4.5.3
point to Flash program memory
access Flash program memory
enable write to memory
disable interrupts
PROTECTION AGAINST
SPURIOUS WRITES
To protect against spurious writes to Flash program
memory, the write initiate sequence must also be
followed. See Section 23.0 “Special Features of the
CPU” for more detail.
4.6
Flash Program Operation During
Code Protection
See Section 23.3 “Program Verification and Code
Protection” for details on code protection of Flash
program memory.
REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values on
page
EEPGD
CFGS
—
FREE
WRERR
WREN
WR
RD
247
EECON2
EEPROM Control Register 2 (not a physical register)
INTCON
GIE/GIEH PEIE/GIEL TMR0IE
247
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR2
OSCFIP
C1IP
C2IP
EEIP
BCLIP
—
TMR3IP
—
248
PIE2
OSCFIE
C1IE
C2IE
EEIE
BCLIE
—
TMR3IE
—
248
OSCFIF
C1IF
C2IF
EEIF
BCLIF
—
TMR3IF
—
248
PIR2
TABLAT
Program Memory Table Latch
245
TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR)
TBLPTRU
—
—
bit 21
245
Program Memory Table Pointer Upper Byte (TBLPTR)
TBPLTRH Program Memory Table Pointer High Byte (TBLPTR)
245
245
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.
2009-2016 Microchip Technology Inc.
DS40001365F-page 53
PIC18(L)F1XK22
5.0
DATA EEPROM MEMORY
The data EEPROM is a nonvolatile memory array,
separate from the data RAM and program memory,
which is used for long-term storage of program data. It
is not directly mapped in either the register file or
program memory space but is indirectly addressed
through the Special Function Registers (SFRs). The
EEPROM is readable and writable during normal
operation over the entire VDD range.
Four SFRs are used to read and write to the data
EEPROM as well as the program memory. They are:
•
•
•
•
EECON1
EECON2
EEDATA
EEADR
The data EEPROM allows byte read and write. When
interfacing to the data memory block, EEDATA holds
the 8-bit data for read/write and the EEADR register
holds the address of the EEPROM location being
accessed.
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; it will
vary with voltage and temperature as well as from chipto-chip. Please refer to parameter US122 (Table 26-24)
for exact limits.
5.1
5.2
Access to the data EEPROM is controlled by two
registers: EECON1 and EECON2. These are the same
registers which control access to the program memory
and are used in a similar manner for the data
EEPROM.
The EECON1 register (Register 5-1) is the control
register for data and program memory access. Control
bit EEPGD determines if the access will be to program
or data EEPROM memory. When the EEPGD bit is
clear, operations will access the data EEPROM
memory. When the EEPGD bit is 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 the CFGS bit is set,
subsequent operations access Configuration registers.
When the CFGS bit is clear, the EEPGD bit selects
either program Flash or data EEPROM memory.
The WREN bit, when set, will allow a write operation.
On power-up, the WREN bit is clear.
The WRERR bit is set by hardware when the WR bit is
set and cleared when the internal programming timer
expires and the write operation is complete.
Note:
EEADR Register
The EEADR register is used to address the data
EEPROM for read and write operations. The 8-bit
range of the register can address a memory range of
256 bytes (00h to FFh).
EECON1 and EECON2 Registers
During normal operation, the WRERR
may read as ‘1’. This can indicate that a
write
operation
was
prematurely
terminated by a Reset, or a write
operation was attempted improperly.
The WR control bit initiates write operations. The bit
can be set but not cleared by software. It is cleared only
by hardware at the completion of the write operation.
Note:
The EEIF interrupt flag bit of the PIR2
register is set when the write is complete.
It must be cleared by software.
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 4.1 “Table Reads
and Table Writes” regarding table reads.
The EECON2 register is not a physical register. It is
used exclusively in the memory write and erase
sequences. Reading EECON2 will read all ‘0’s.
DS40001365F-page 54
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 5-1:
EECON1: DATA EEPROM CONTROL 1 REGISTER
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
WREN
WR
RD
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
S = Bit can be set by software, but not cleared
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘0’ = Bit is cleared
‘1’ = Bit is set
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 (Block) Erase Enable bit
1 = Erase the program memory block 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) by 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 by hardware. The RD bit can only
be set (not cleared) by 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.
2009-2016 Microchip Technology Inc.
DS40001365F-page 55
PIC18(L)F1XK22
5.3
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 of the EECON1 register and then set control
bit, RD. The data is available on 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).
The basic process is shown in Example 5-1.
5.4
Writing to the Data EEPROM
Memory
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. Both WR and WREN cannot be set with the same
instruction.
At the completion of the write cycle, the WR bit is
cleared by 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.
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 5-2 must be followed to initiate the write cycle.
5.5
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.
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.
EXAMPLE 5-1:
MOVLW
MOVWF
BCF
BCF
BSF
MOVF
DATA EEPROM READ
DATA_EE_ADDR
EEADR
EECON1, EEPGD
EECON1, CFGS
EECON1, RD
EEDATA, W
EXAMPLE 5-2:
Required
Sequence
Write Verify
;
;
;
;
;
;
Data Memory Address to read
Point to DATA memory
Access EEPROM
EEPROM Read
W = EEDATA
DATA EEPROM WRITE
MOVLW
MOVWF
MOVLW
MOVWF
BCF
BCF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BSF
DATA_EE_ADDR_LOW
EEADR
DATA_EE_DATA
EEDATA
EECON1, EEPGD
EECON1, CFGS
EECON1, WREN
INTCON, GIE
55h
EECON2
0AAh
EECON2
EECON1, WR
INTCON, GIE
;
;
;
;
;
;
;
;
;
;
;
;
;
;
BCF
EECON1, WREN
; User code execution
; Disable writes on write complete (EEIF set)
DS40001365F-page 56
Data Memory Address to write
Data Memory Value to write
Point to DATA memory
Access EEPROM
Enable writes
Disable Interrupts
Write 55h
Write 0AAh
Set WR bit to begin write
Enable Interrupts
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
5.6
Operation During Code-Protect
5.8
Data EEPROM memory has its own code-protect bits in
Configuration Words. External read and write
operations are disabled if code protection is 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 23.0
“Special Features of the CPU” for additional
information.
5.7
Protection Against Spurious Write
There are conditions when the user may not want to
write to the data EEPROM memory. To protect against
spurious EEPROM writes, various mechanisms have
been implemented. On power-up, the WREN bit is
cleared. In addition, writes to the EEPROM are blocked
during the Power-up Timer period (TPWRT,
parameter 33).
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).
When variables in one section change frequently, while
variables in another section do not change, it is possible
to exceed the total number of write cycles to the
EEPROM without exceeding the total number of write
cycles to a single byte. If this is the case, then 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 5-3.
Note:
The write initiate sequence and the WREN bit together
help prevent an accidental write during brown-out,
power glitch or software malfunction.
EXAMPLE 5-3:
EEADR
EECON1,
EECON1,
INTCON,
EECON1,
BSF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BTFSC
BRA
INCFSZ
BRA
EECON1, RD
55h
EECON2
0AAh
EECON2
EECON1, WR
EECON1, WR
$-2
EEADR, F
LOOP
BCF
BSF
EECON1, WREN
INTCON, GIE
;
;
;
;
;
;
;
;
;
;
;
;
;
CFGS
EEPGD
GIE
WREN
Loop
Name
EEADR
EECON1
Start at address 0
Set for memory
Set for Data EEPROM
Disable interrupts
Enable writes
Loop to refresh array
Read current address
Write 55h
Write 0AAh
Set WR bit to begin write
Wait for write to complete
; Increment address
; Not zero, do it again
; Disable writes
; Enable interrupts
REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY
Bit 7
Bit 6
EEADR7
EEADR6
EEPGD
CFGS
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
EEADR5 EEADR4 EEADR3 EEADR2 EEADR1 EEADR0
—
FREE
WRERR
EECON2
EEPROM Control Register 2 (not a physical register)
EEDATA
EEPROM Data Register
INTCON
If data EEPROM is only used to store
constants and/or data that changes rarely,
an array refresh is likely not required. See
specification.
DATA EEPROM REFRESH ROUTINE
CLRF
BCF
BCF
BCF
BSF
TABLE 5-1:
Using the Data EEPROM
WREN
WR
RD
Reset
Values
on page
247
247
247
247
GIE/GIEH
PEIE/GIEL
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR2
OSCFIP
C1IP
C2IP
EEIP
BCLIP
—
TMR3IP
—
248
PIE2
OSCFIE
C1IE
C2IE
EEIE
BCLIE
—
TMR3IE
—
248
PIR2
OSCFIF
C1IF
C2IF
EEIF
BCLIF
—
TMR3IF
—
248
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.
2009-2016 Microchip Technology Inc.
DS40001365F-page 57
PIC18(L)F1XK22
6.0
8 x 8 HARDWARE MULTIPLIER
6.1
Introduction
EXAMPLE 6-1:
MOVF
MULWF
All PIC18 devices include an 8 x 8 hardware multiplier
as part of the ALU. The multiplier performs an unsigned
operation and yields a 16-bit result that is stored in the
product register pair, PRODH:PRODL. The multiplier’s
operation does not affect any flags in the STATUS
register.
ARG1, W
ARG2
;
; ARG1 * ARG2 ->
; PRODH:PRODL
EXAMPLE 6-2:
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 6-1.
6.2
8 x 8 UNSIGNED
MULTIPLY ROUTINE
8 x 8 SIGNED MULTIPLY
ROUTINE
MOVF
MULWF
ARG1, W
ARG2
BTFSC
SUBWF
ARG2, SB
PRODH, F
MOVF
BTFSC
SUBWF
ARG2, W
ARG1, SB
PRODH, F
;
;
;
;
;
ARG1 * ARG2 ->
PRODH:PRODL
Test Sign Bit
PRODH = PRODH
- ARG1
; Test Sign Bit
; PRODH = PRODH
;
- ARG2
Operation
Example 6-1 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 6-2 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.
TABLE 6-1:
PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS
Routine
8 x 8 unsigned
8 x 8 signed
16 x 16 unsigned
16 x 16 signed
DS40001365F-page 58
Multiply Method
Program
Memory
(Words)
Cycles
(Max)
Time
@ 40 MHz
@ 10 MHz
@ 4 MHz
Without hardware multiply
13
69
6.9 s
27.6 s
69 s
Hardware multiply
1
1
100 ns
400 ns
1 s
Without hardware multiply
33
91
9.1 s
36.4 s
91 s
Hardware multiply
6
6
600 ns
2.4 s
6 s
Without hardware multiply
21
242
24.2 s
96.8 s
242 s
Hardware multiply
28
28
2.8 s
11.2 s
28 s
Without hardware multiply
52
254
25.4 s
102.6 s
254 s
Hardware multiply
35
40
4.0 s
16.0 s
40 s
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
Example 6-3 shows the sequence to do a 16 x 16
unsigned multiplication. Equation 6-1 shows the
algorithm that is used. The 32-bit result is stored in four
registers (RES).
EQUATION 6-1:
RES3:RES0
=
=
EXAMPLE 6-3:
16 x 16 UNSIGNED
MULTIPLICATION
ALGORITHM
ARG1H:ARG1L ARG2H:ARG2L
(ARG1H ARG2H 216) +
(ARG1H ARG2L 28) +
(ARG1L ARG2H 28) +
(ARG1L ARG2L)
EQUATION 6-2:
RES3:RES0 = ARG1H:ARG1L ARG2H:ARG2L
= (ARG1H ARG2H 216) +
(ARG1H ARG2L 28) +
(ARG1L ARG2H 28) +
(ARG1L ARG2L) +
(-1 ARG2H ARG1H:ARG1L 216) +
(-1 ARG1H ARG2H:ARG2L 216)
EXAMPLE 6-4:
16 x 16 UNSIGNED
MULTIPLY ROUTINE
MOVF
MULWF
ARG1L, W
ARG2L
MOVFF
MOVFF
PRODH, RES1
PRODL, RES0
MOVF
MULWF
ARG1H, W
ARG2H
MOVFF
MOVFF
PRODH, RES3
PRODL, RES2
MOVF
MULWF
ARG1L, W
ARG2H
MOVF
ADDWF
MOVF
ADDWFC
CLRF
ADDWFC
PRODL, W
RES1, F
PRODH, W
RES2, F
WREG
RES3, F
MOVF
MULWF
ARG1H, W
ARG2L
MOVF
ADDWF
MOVF
ADDWFC
CLRF
ADDWFC
PRODL, W
RES1, F
PRODH, W
RES2, F
WREG
RES3, F
; ARG1L * ARG2L->
; PRODH:PRODL
;
;
ARG1L * ARG2H->
PRODH:PRODL
Add cross
products
ARG1H * ARG2L->
PRODH:PRODL
Add cross
products
Example 6-4 shows the sequence to do a 16 x 16
signed multiply. Equation 6-2 shows the algorithm
used. The 32-bit result is stored in four registers
(RES). To account for the sign bits of the
arguments, the MSb for each argument pair is tested
and the appropriate subtractions are done.
2009-2016 Microchip Technology Inc.
ARG1L, W
ARG2L
MOVFF
MOVFF
PRODH, RES1
PRODL, RES0
MOVF
MULWF
ARG1H, W
ARG2H
MOVFF
MOVFF
PRODH, RES3
PRODL, RES2
MOVF
MULWF
ARG1L, W
ARG2H
MOVF
ADDWF
MOVF
ADDWFC
CLRF
ADDWFC
PRODL, W
RES1, F
PRODH, W
RES2, F
WREG
RES3, F
MOVF
MULWF
ARG1H, W
ARG2L
MOVF
ADDWF
MOVF
ADDWFC
CLRF
ADDWFC
PRODL, W
RES1, F
PRODH, W
RES2, F
WREG
RES3, F
BTFSS
BRA
MOVF
SUBWF
MOVF
SUBWFB
ARG2H, 7
SIGN_ARG1
ARG1L, W
RES2
ARG1H, W
RES3
; ARG2H:ARG2L neg?
; no, check ARG1
;
;
;
ARG1H, 7
CONT_CODE
ARG2L, W
RES2
ARG2H, W
RES3
; ARG1H:ARG1L neg?
; no, done
;
;
;
; ARG1L * ARG2L ->
; PRODH:PRODL
;
;
; ARG1H * ARG2H ->
; PRODH:PRODL
;
;
;
;
;
;
;
;
;
;
ARG1L * ARG2H ->
PRODH:PRODL
Add cross
products
;
;
;
;
;
;
;
;
;
;
;
MOVF
MULWF
;
;
;
;
;
;
;
;
;
;
16 x 16 SIGNED
MULTIPLY ROUTINE
;
;
; ARG1H * ARG2H->
; PRODH:PRODL
;
;
16 x 16 SIGNED
MULTIPLICATION
ALGORITHM
;
;
;
;
;
;
;
;
;
ARG1H * ARG2L ->
PRODH:PRODL
Add cross
products
;
;
SIGN_ARG1
BTFSS
BRA
MOVF
SUBWF
MOVF
SUBWFB
;
CONT_CODE
:
DS40001365F-page 59
PIC18(L)F1XK22
7.0
INTERRUPTS
The PIC18(L)F1XK22 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. A high priority interrupt event will interrupt a
low priority interrupt that may be in progress.
There are twelve registers which are used to control
interrupt operation. These registers are:
•
•
•
•
•
•
•
RCON
INTCON
INTCON2
INTCON3
PIR1, PIR2
PIE1, PIE2
IPR1, IPR2
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
7.1
Mid-Range Compatibility
When the IPEN bit is cleared (default state), the interrupt
priority feature is disabled and interrupts are compatible
with PIC® microcontroller mid-range devices. In
Compatibility mode, the interrupt priority bits of the IPRx
registers have no effect. The PEIE bit of the INTCON
register is the global interrupt enable for the peripherals.
The PEIE bit disables only the peripheral interrupt
sources and enables the peripheral interrupt sources
when the GIE bit is also set. The GIE bit of the INTCON
register is the global interrupt enable which enables all
non-peripheral interrupt sources and disables all
interrupt sources, including the peripherals. All interrupts
branch to address 0008h in Compatibility mode.
DS40001365F-page 60
7.2
Interrupt Priority
The interrupt priority feature is enabled by setting the
IPEN bit of the RCON register. When interrupt priority
is enabled the GIE and PEIE global interrupt enable
bits of Compatibility mode are replaced by the GIEH
high priority, and GIEL low priority, global interrupt
enables. When set, the GIEH bit of the INTCON
register enables all interrupts that have their associated
IPRx register or INTCONx register priority bit set (high
priority). When clear, the GIEL bit disables all interrupt
sources including those selected as low priority. When
clear, the GIEL bit of the INTCON register disables only
the interrupts that have their associated priority bit
cleared (low priority). When set, the GIEL bit enables
the low priority sources when the GIEH bit is also set.
When the interrupt flag, enable bit and appropriate
global interrupt enable bit are all set, the interrupt will
vector immediately to address 0008h for high priority,
or 0018h for low priority, depending on level of the
interrupting source’s priority bit. Individual interrupts
can be disabled through their corresponding interrupt
enable bits.
7.3
Interrupt Response
When an interrupt is responded to, the global interrupt
enable bit is cleared to disable further interrupts. The
GIE bit is the global interrupt enable when the IPEN bit
is cleared. When the IPEN bit is set, enabling interrupt
priority levels, the GIEH bit is the high priority global
interrupt enable and the GIEL bit is the low priority
global interrupt enable. 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 in the INTCONx and PIRx
registers. The interrupt flag bits must be cleared by
software before re-enabling interrupts to avoid
repeating the same interrupt.
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 interrupt-on-change, the interrupt latency
will be three to four instruction cycles. The exact
latency is the same for one-cycle or two-cycle
instructions. Individual interrupt flag bits are set,
regardless of the status of their corresponding enable
bits or the global interrupt enable bit.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
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.
FIGURE 7-1:
PIC18 INTERRUPT LOGIC
TMR0IF
TMR0IE
TMR0IP
RABIF
RABIE
RABIP
INT0IF
INT0IE
Wake-up if in
Idle or Sleep modes
(1)
Interrupt to CPU
Vector to Location
0008h
INT1IF
INT1IE
INT1IP
INT2IF
INT2IE
INT2IP
SSPIF
SSPIE
SSPIP
GIEH/GIE
ADIF
ADIE
ADIP
IPEN
IPEN
GIEL/PEIE
RCIF
RCIE
RCIP
IPEN
Additional Peripheral Interrupts
High Priority Interrupt Generation
Low Priority Interrupt Generation
SSPIF
SSPIE
SSPIP
ADIF
ADIE
ADIP
RCIF
RCIE
RCIP
Interrupt to CPU
Vector to Location
0018h
TMR0IF
TMR0IE
TMR0IP
RABIF
RABIE
RABIP
(1)
GIEH/GIE
GIEL/PEIE
INT1IF
INT1IE
INT1IP
Additional Peripheral Interrupts
INT2IF
INT2IE
INT2IP
Note
1:
The RABIF interrupt also requires the individual pin IOCA and IOCB enable.
2009-2016 Microchip Technology Inc.
DS40001365F-page 61
PIC18(L)F1XK22
7.4
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
enable bit. User software should ensure
the appropriate interrupt flag bits are clear
prior to enabling an interrupt. This feature
allows for software polling.
REGISTER 7-1:
INTCON: INTERRUPT CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-x
GIE/GIEH
PEIE/GIEL
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
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 including peripherals
When IPEN = 1:
1 = Enables all high priority interrupts
0 = Disables all interrupts including low priority
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 interrupts
0 = Disables all low priority 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
RABIE: RA and RB Port Change Interrupt Enable bit(2)
1 = Enables the RA and RB port change interrupt
0 = Disables the RA and RB port change interrupt
bit 2
TMR0IF: TMR0 Overflow Interrupt Flag bit
1 = TMR0 register has overflowed (must be cleared by software)
0 = TMR0 register did not overflow
bit 1
INT0IF: INT0 External Interrupt Flag bit
1 = The INT0 external interrupt occurred (must be cleared by software)
0 = The INT0 external interrupt did not occur
bit 0
RABIF: RA and RB Port Change Interrupt Flag bit(1)
1 = At least one of the RA or RB pins changed state (must be cleared by software)
0 = None of the RA or RB pins have changed state
Note
1:
2:
A mismatch condition will continue to set the RABIF bit. Reading PORTA and PORTB will end the mismatch condition and allow the bit to
be cleared.
RA and RB port change interrupts also require the individual pin IOCA and IOCB enable.
DS40001365F-page 62
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PIC18(L)F1XK22
REGISTER 7-2:
INTCON2: INTERRUPT CONTROL 2 REGISTER
R/W-1
R/W-1
R/W-1
R/W-1
U-0
R/W-1
U-0
R/W-1
RABPU
INTEDG0
INTEDG1
INTEDG2
—
TMR0IP
—
RABIP
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
RABPU: PORTA and PORTB Pull-up Enable bit
1 = PORTA and PORTB pull-ups are disabled
0 = PORTA and PORTB pull-ups are enabled provided that the pin is an input and the corresponding
WPUA and WPUB bits are set.
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
Unimplemented: Read as ‘0’
bit 2
TMR0IP: TMR0 Overflow Interrupt Priority bit
1 = High priority
0 = Low priority
bit 1
Unimplemented: Read as ‘0’
bit 0
RABIP: RA and 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
enable bit. User software might ensure the
appropriate interrupt flag bits are clear
prior to enabling an interrupt. This feature
allows for software polling.
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DS40001365F-page 63
PIC18(L)F1XK22
REGISTER 7-3:
INTCON3: INTERRUPT CONTROL 3 REGISTER
R/W-1
R/W-1
U-0
R/W-0
R/W-0
U-0
R/W-0
R/W-0
INT2IP
INT1IP
—
INT2IE
INT1IE
—
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
Unimplemented: Read as ‘0’
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
Unimplemented: Read as ‘0’
bit 1
INT2IF: INT2 External Interrupt Flag bit
1 = The INT2 external interrupt occurred (must be cleared by 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 by 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
enable bit. User software might ensure the
appropriate interrupt flag bits are clear
prior to enabling an interrupt. This feature
allows for software polling.
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PIC18(L)F1XK22
7.5
PIR Registers
The PIR registers contain the individual flag bits for the
peripheral interrupts. Due to the number of peripheral
interrupt sources, there are two Peripheral Interrupt
Request Flag registers (PIR1 and PIR2).
Note 1: Interrupt flag bits are set when an
interrupt condition occurs, regardless of
the state of its corresponding enable bit or
the Global Interrupt Enable bit, GIE of the
INTCON register.
2: User software might ensure the
appropriate interrupt flag bits are cleared
prior to enabling an interrupt and after
servicing that interrupt.
REGISTER 7-4:
PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1
U-0
R/W-0
R-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
Unimplemented: Read as ‘0’
bit 6
ADIF: A/D Converter Interrupt Flag bit
1 = An A/D conversion completed (must be cleared by software)
0 = The A/D conversion is not complete or has not been started
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
SSPIF: Master Synchronous Serial Port Interrupt Flag bit
1 = The transmission/reception is complete (must be cleared by software)
0 = Waiting to transmit/receive
bit 2
CCP1IF: CCP1 Interrupt Flag bit
Capture mode:
1 = A TMR1 register capture occurred (must be cleared by software)
0 = No TMR1 register capture occurred
Compare mode:
1 = A TMR1 register compare match occurred (must be cleared by software)
0 = No TMR1 register compare match occurred
PWM mode:
Unused in this mode
bit 1
TMR2IF: TMR2 to PR2 Match Interrupt Flag bit
1 = TMR2 to PR2 match occurred (must be cleared by software)
0 = No TMR2 to PR2 match occurred
bit 0
TMR1IF: TMR1 Overflow Interrupt Flag bit
1 = TMR1 register overflowed (must be cleared by software)
0 = TMR1 register did not overflow
Note 1: The PSPIF bit is unimplemented on 28-pin devices and will read as ‘0’.
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DS40001365F-page 65
PIC18(L)F1XK22
REGISTER 7-5:
PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
U-0
R/W-0
U-0
OSCFIF
C1IF
C2IF
EEIF
BCLIF
—
TMR3IF
—
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 HFINTOSC (must be cleared by software)
0 = Device clock operating
bit 6
C1IF: Comparator C1 Interrupt Flag bit
1 = Comparator C1 output has changed (must be cleared by software)
0 = Comparator C1 output has not changed
bit 5
C2IF: Comparator C2 Interrupt Flag bit
1 = Comparator C2 output has changed (must be cleared by software)
0 = Comparator C2 output has not changed
bit 4
EEIF: Data EEPROM/Flash Write Operation Interrupt Flag bit
1 = The write operation is complete (must be cleared by software)
0 = The write operation is not complete or has not been started
bit 3
BCLIF: Bus Collision Interrupt Flag bit
1 = A bus collision occurred (must be cleared by software)
0 = No bus collision occurred
bit 2
Unimplemented: Read as ‘0’
bit 1
TMR3IF: TMR3 Overflow Interrupt Flag bit
1 = TMR3 register overflowed (must be cleared by software)
0 = TMR3 register did not overflow
bit 0
Unimplemented: Read as ‘0’
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PIC18(L)F1XK22
7.6
PIE Registers
The PIE registers contain the individual enable bits for
the peripheral interrupts. Due to the number of
peripheral interrupt sources, there are two Peripheral
Interrupt Enable registers (PIE1 and PIE2). When IPEN
= 0, the PEIE bit must be set to enable any of these
peripheral interrupts.
REGISTER 7-6:
PIE1: PERIPHERAL INTERRUPT ENABLE (FLAG) REGISTER 1
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
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
SSPIE: Master Synchronous Serial Port Interrupt Enable bit
1 = Enables the MSSP interrupt
0 = Disables the MSSP interrupt
bit 2
CCP1IE: CCP1 Interrupt Enable bit
1 = Enables the CCP1 interrupt
0 = Disables the CCP1 interrupt
bit 1
TMR2IE: TMR2 to PR2 Match Interrupt Enable bit
1 = Enables the TMR2 to PR2 match interrupt
0 = Disables the TMR2 to PR2 match interrupt
bit 0
TMR1IE: TMR1 Overflow Interrupt Enable bit
1 = Enables the TMR1 overflow interrupt
0 = Disables the TMR1 overflow interrupt
2009-2016 Microchip Technology Inc.
x = Bit is unknown
DS40001365F-page 67
PIC18(L)F1XK22
REGISTER 7-7:
PIE2: PERIPHERAL INTERRUPT ENABLE (FLAG) REGISTER 2
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
U-0
R/W-0
U-0
OSCFIE
C1IE
C2IE
EEIE
BCLIE
—
TMR3IE
—
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
bit 7
OSCFIE: Oscillator Fail Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 6
C1IE: Comparator C1 Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 5
C2IE: Comparator C2 Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 4
EEIE: Data EEPROM/Flash Write Operation Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 3
BCLIE: Bus Collision Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 2
Unimplemented: Read as ‘0’
bit 1
TMR3IE: TMR3 Overflow Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 0
Unimplemented: Read as ‘0’
DS40001365F-page 68
x = Bit is unknown
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PIC18(L)F1XK22
7.7
IPR Registers
The IPR registers contain the individual priority bits for the
peripheral interrupts. Due to the number of peripheral
interrupt sources, there are two Peripheral Interrupt
Priority registers (IPR1 and IPR2). Using the priority bits
requires that the Interrupt Priority Enable (IPEN) bit be
set.
REGISTER 7-8:
IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1
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
SSPIP
CCP1IP
TMR2IP
TMR1IP
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
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
x = Bit is unknown
1 = High priority
0 = Low priority
bit 3
SSPIP: Master Synchronous Serial Port Interrupt Priority bit
1 = High priority
0 = Low priority
bit 2
CCP1IP: CCP1 Interrupt Priority bit
1 = High priority
0 = Low priority
bit 1
TMR2IP: TMR2 to PR2 Match Interrupt Priority bit
1 = High priority
0 = Low priority
bit 0
TMR1IP: TMR1 Overflow Interrupt Priority bit
1 = High priority
0 = Low priority
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PIC18(L)F1XK22
REGISTER 7-9:
IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
U-0
R/W-1
U-0
OSCFIP
C1IP
C2IP
EEIP
BCLIP
—
TMR3IP
—
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
bit 7
OSCFIP: Oscillator Fail Interrupt Priority bit
1 = High priority
0 = Low priority
bit 6
C1IP: Comparator C1 Interrupt Priority bit
1 = High priority
0 = Low priority
bit 5
C2IP: Comparator C2 Interrupt Priority bit
1 = High priority
0 = Low priority
bit 4
EEIP: Data EEPROM/Flash Write Operation Interrupt Priority bit
1 = High priority
0 = Low priority
bit 3
BCLIP: Bus Collision Interrupt Priority bit
1 = High priority
0 = Low priority
bit 2
Unimplemented: Read as ‘0’
bit 1
TMR3IP: TMR3 Overflow Interrupt Priority bit
1 = High priority
0 = Low priority
bit 0
Unimplemented: Read as ‘0’
DS40001365F-page 70
x = Bit is unknown
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PIC18(L)F1XK22
7.8
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 22.1 “RCON
Register”.
REGISTER 7-10:
R/W-0
IPEN
RCON: RESET CONTROL REGISTER
R/W-1
SBOREN
U-0
(1)
—
R/W-1
RI
R-1
TO
R-1
R/W-0
R/W-0
PD
(2)
BOR(3)
POR
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 BOREN = 01:
1 = BOR is enabled
0 = BOR is disabled
If BOREN = 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 or Power-on Reset)
0 = The RESET instruction was executed causing a device Reset (must be set in firmware after a
code-executed 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 = No Power-on Reset occurred
0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)
bit 0
BOR: Brown-out Reset Status bit(3)
1 = A Brown-out Reset has not occurred (set by firmware only)
0 = A Brown-out Reset occurred (must be set by firmware after a POR or Brown-out Reset occurs)
Note 1:
2:
3:
If SBOREN is enabled, its Reset state is ‘1’; otherwise, it is ‘0’.
The actual Reset value of POR is determined by the type of device Reset. See the notes following this
register and Section 22.6 “Reset State of Registers” for additional information.
See Table 22-3.
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PIC18(L)F1XK22
7.9
INTx Pin Interrupts
7.10
External interrupts on the INT0, INT1 and INT2 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 INTx
pin, the corresponding flag bit, INTxF, is set. This
interrupt can be disabled by clearing the corresponding
enable bit, INTxE. Flag bit, INTxF, must be cleared by
software in the Interrupt Service Routine before reenabling the interrupt.
All external interrupts (INT0, INT1 and INT2) can wakeup the processor from Idle or Sleep modes if bit INTxE
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 and INT2 is determined by
the value contained in the interrupt priority bits,
INT1IP and INT2IP of the INTCON3 register. There is
no priority bit associated with INT0. It is always a highpriority interrupt source.
TMR0 Interrupt
In 8-bit mode (which is the default), an overflow in the
TMR0 register (FFh 00h) will set flag bit, TMR0IF. In
16-bit mode, an overflow in the TMR0H:TMR0L
register pair (FFFFh 0000h) will set TMR0IF. The
interrupt can be enabled/disabled by setting/clearing
enable bit, TMR0IE of the INTCON register. Interrupt
priority for Timer0 is determined by the value contained
in the interrupt priority bit, TMR0IP of the INTCON2
register. See Section 9.0 “Timer0 Module” for further
details on the Timer0 module.
7.11
PORTA and PORTB Interrupt-onChange
An input change on PORTA or PORTB sets flag bit,
RABIF of the INTCON register. The interrupt can be
enabled/disabled by setting/clearing enable bit, RABIE
of the INTCON register. Pins must also be individually
enabled with the IOCA and IOCB register. Interrupt
priority for PORTA and PORTB interrupt-on-change is
determined by the value contained in the interrupt
priority bit, RABIP of the INTCON2 register.
7.12
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 3.3
“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 7-1 saves and restores the WREG,
STATUS and BSR registers during an Interrupt Service
Routine.
EXAMPLE 7-1:
SAVING STATUS, WREG AND BSR REGISTERS IN RAM
MOVWF
W_TEMP
MOVFF
STATUS, STATUS_TEMP
MOVFF
BSR, BSR_TEMP
;
; USER ISR CODE
;
MOVFF
BSR_TEMP, BSR
MOVF
W_TEMP, W
MOVFF
STATUS_TEMP, STATUS
DS40001365F-page 72
; W_TEMP is in virtual bank
; STATUS_TEMP located anywhere
; BSR_TMEP located anywhere
; Restore BSR
; Restore WREG
; Restore STATUS
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
8.0
I/O PORTS
8.1
There are up to three 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)
The PORTA Data Latch (LATA 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 8-1.
FIGURE 8-1:
GENERIC I/O PORT
OPERATION
WR LAT
or Port
D
Q
(1)
I/O pin
CK
WR TRIS
Reading the PORTA register reads the status of the
pins, whereas writing to it, will write to the PORT latch.
The PORTA Data Latch (LATA) register is also memory
mapped. Read-modify-write operations on the LATA
register read and write the latched output value for
PORTA.
All of the PORTA pins are individually configurable as
interrupt-on-change pins. Control bits in the IOCA
register enable (when set) or disable (when clear) the
interrupt function for each pin.
Only pins configured as inputs can cause this interrupt
to occur (i.e., any pin configured as an output is
excluded from the interrupt-on-change comparison).
For enabled interrupt-on-change pins, the values are
compared with the old value latched on the last read of
PORTA. The ‘mismatch’ outputs of the last read are
OR’d together to set the PORTA Change Interrupt flag
bit (RABIF) in the INTCON register.
Data Latch
D
PORTA is a 6-bit wide, bidirectional port, with the
exception of RA3, which is input-only and its TRIS bit
will always read as ‘1’. The corresponding data
direction register is TRISA. Setting a TRISA bit (= 1)
will make the corresponding PORTA pin an input (i.e.,
disable the output driver). Clearing a TRISA bit (= 0)
will make the corresponding PORTA pin an output (i.e.,
enable the output driver and put the contents of the
output latch on the selected pin).
When set, the RABIE bit of the INTCON register
enables interrupts on all pins which also have their
corresponding IOCA bit set. When clear, the RABIE
bit disables all interrupt-on-changes.
RD LAT
Data
Bus
PORTA, TRISA and LATA Registers
Q
CK
TRIS Latch
Input
Buffer
RD TRIS
Q
D
ENEN
RD Port
Note 1:
I/O pins have diode protection to VDD and VSS.
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PIC18(L)F1XK22
This interrupt can wake the device from the Sleep mode,
or any of the Idle modes. The user, in the Interrupt
Service Routine, can clear the interrupt in the following
manner:
a)
b)
Any read or write of PORTA to clear the
mismatch condition (except when PORTA is the
source or destination of a MOVFF instruction).
Clear the flag bit, RABIF.
A mismatch condition will continue to set the RABIF flag
bit. Reading or writing PORTA will end the mismatch
condition and allow the RABIF bit to be cleared. The latch
holding the last read value is not affected by a MCLR nor
Brown-out Reset. After either one of these Resets, the
RABIF flag will continue to be set if a mismatch is present.
Note 1: If a change on the I/O pin should occur
when the read operation is being
executed (start of the Q2 cycle), then the
RABIF interrupt flag may not get set.
Furthermore, since a read or write on a
port affects all bits of that port, care must
be taken when using multiple pins in
Interrupt-on-Change mode. Changes on
one pin may not be seen while servicing
changes on another pin.
Pins RA4 and RA5 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
Configuration
register
(see
Section 23.1
“Configuration Bits” for details). When they are not
used as port pins, RA4 and RA5 and their associated
TRIS and LAT bits read as ‘0’.
RA are pins multiplexed with analog inputs. The
operation of pins RA as analog are selected by
setting the ANS bits in the ANSEL register, which
is the default setting after a Power-on Reset.
EXAMPLE 8-1:
CLRF
PORTA
CLRF
LATA
MOVLW
030h
MOVWF
TRISA
INITIALIZING PORTA
;
;
;
;
;
;
;
;
;
;
Initialize PORTA by
clearing output
data latches
Alternate method
to clear output
data latches
Value used to
initialize data
direction
Set RA as output
The interrupt-on-change feature is recommended for
wake-up on key depression operation and operations
where PORTA is only used for the interrupt-on-change
feature. Polling of PORTA is not recommended while
using the interrupt-on-change feature.
Each of the PORTA pins has an individually controlled
weak internal pull-up. When set, each bit of the WPUA
register enables the corresponding pin pull-up. When
cleared, the RABPU bit of the INTCON2 register
enables pull-ups on all pins which also have their
corresponding WPUA bit set. When set, the RABPU bit
disables all weak pull-ups. 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.
RA3 is an input only pin. Its operation is controlled by
the MCLRE bit of the CONFIG3H register. When
selected as a port pin (MCLRE = 0), it functions as a
digital input only pin; as such, it does not have TRIS or
LAT bits associated with its operation.
Note:
On a Power-on Reset, RA3 is enabled as
a digital input only if Master Clear
functionality is disabled.
DS40001365F-page 74
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 8-1:
PORTA: PORTA REGISTER
U-0
U-0
R/W-x
R/W-x
R-x
R/W-x
R/W-x
R/W-x
—
—
RA5
RA4
RA3
RA2
RA1
RA0
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
bit 7-6
Unimplemented: Read as ‘0’
bit 5-0
RA: PORTA I/O Pin bit(1)
1 = Port pin is > VIH
0 = Port pin is < VIL
Note 1:
x = Bit is unknown
The RA3 bit is only available when Master Clear Reset is disabled (MCLRE Configuration bit = 0).
Otherwise, RA3 reads as ‘0’. This bit is read-only.
REGISTER 8-2:
TRISA: PORTA TRI-STATE REGISTER
U-0
U-0
R/W-1
R/W-1
U-1
R/W-1
R/W-1
R/W-1
—
—
TRISA5
TRISA4
—
TRISA2
TRISA1
TRISA0
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
bit 7-6
Unimplemented: Read as ‘0’
bit 5-4
TRISA: PORTA Tri-State Control bit(1)
1 = PORTA pin configured as an input (tri-stated)
0 = PORTA pin configured as an output
bit 3
Unimplemented: Read as ‘1’
bit 2-0
TRISA: PORTA Tri-State Control bit(1)
1 = PORTA pin configured as an input (tri-stated)
0 = PORTA pin configured as an output
Note 1:
x = Bit is unknown
TRISA always reads ‘1’ in XT, HS and LP Oscillator modes.
2009-2016 Microchip Technology Inc.
DS40001365F-page 75
PIC18(L)F1XK22
REGISTER 8-3:
LATA: PORTA DATA LATCH REGISTER
U-0
U-0
R/W-x
R/W-x
U-0
R/W-x
R/W-x
R/W-x
—
—
LATA5
LATA4
—
LATA2
LATA1
LATA0
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
bit 7-6
Unimplemented: Read as ‘0’
bit 5-4
LATA: RA Port I/O Output Latch Register bits
bit 3
Unimplemented: Read as ‘0’
bit 2-0
LATA: RA Port I/O Output Latch Register bits
REGISTER 8-4:
x = Bit is unknown
WPUA: WEAK PULL-UP PORTA REGISTER
U-0
U-0
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
—
—
WPUA5
WPUA4
WPUA3(1)
WPUA2
WPUA1
WPUA0
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
bit 7-6
Unimplemented: Read as ‘0’
bit 5-0
WPUA: Weak Pull-up Enable bit
1 = Pull-up enabled
0 = Pull-up disabled
Note 1:
x = Bit is unknown
For the WPUA3 bit, when MCLRE = 1, weak pull-up is internally enabled, but not reported here.
REGISTER 8-5:
IOCA: INTERRUPT-ON-CHANGE PORTA REGISTER
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
IOCA5
IOCA4
IOCA3
IOCA2
IOCA1
IOCA0
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
bit 7-6
Unimplemented: Read as ‘0’
bit 5-0
IOCA: PORTA I/O Pin bit
1 = Interrupt-on-change enabled
0 = Interrupt-on-change disabled
DS40001365F-page 76
x = Bit is unknown
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 8-1:
Pin
RA0/AN0/CVREF/
DAC1OUT/VREF-/
C1IN+/INT0/PGD
PORTA I/O SUMMARY
Function
TRIS
Setting
I/O
I/O
Type
RA0
0
O
DIG
RA2/AN2/C1OUT/
T0CKI/INT2/SRQ
RA3/MCLR/VPP
RA4/AN3/OSC2/
CLKOUT
RA5/OSC1/CLKIN/
T13CKI
Legend:
Note 1:
LATA data output.
1
I
TTL
PORTA data input; Programmable weak pull-up.
AN0
1
I
ANA
ADC channel 0 input.
CVREF/
DAC1OUT
x
O
ANA
DAC reference voltage output.
VREF-
1
I
ANA
ADC and DAC reference voltage (low) input.
C1IN+
1
I
DIG
Comparator C1 noninverting input.
INT0
1
I
ST
External interrupt 0.
PGD
RA1/AN1/C12IN0-/
VREF+/INT1/PGC
Description
x
O
DIG
Serial execution data output for ICSP™.
x
I
ST
Serial execution data input for ICSP.
0
O
DIG
LATA data output.
1
I
TTL
PORTA data input; Programmable weak pull-up.
AN1
1
I
ANA
ADC channel 1.
C12IN0-
1
I
ANA
Comparator C1 and C2 inverting input channel 0.
VREF+
1
I
ANA
ADC and DAC reference voltage (high) input
INT1
1
ST
External interrupt 1.
PGC
x
O
DIG
Serial execution clock output for ICSP™.
x
I
ST
Serial execution clock input for ICSP.
RA2
0
O
DIG
LATA data output.
1
I
TTL
PORTA data input; Programmable weak pull-up.
RA1
AN2
1
I
ANA
ADC channel 2.
C1OUT
0
O
DIG
Comparator C1 output.
T0CKI
1
I
ST
Timer0 external clock input.
INT2
1
I
ST
External interrupt 2.
SRQ
0
O
DIG
SR latch output.
RA3
—(1)
I
ST
PORTA data input; Programmable weak pull-up.
MCLR
—
I
ST
Active-low Master Clear with internal pull-up.
VPP
—
I
ANA
High-voltage programming input.
RA4
0
O
DIG
LATA data output.
1
I
TTL
PORTA data input; Programmable weak pull-up.
AN3
1
I
ANA
A/D input channel 3.
OSC2
x
O
ANA
Main oscillator feedback output connection (XT, HS and LP modes).
CLKOUT
x
O
DIG
System instruction cycle clock output.
RA5
0
O
DIG
LATA data output.
1
I
TTL
PORTA data input; Programmable weak pull-up.
OSC1
x
I
ANA
Main oscillator input connection.
CLKIN
x
I
ANA
Main clock input connection.
T13CKI
1
I
ST
Timer1 and Timer3 external clock input.
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).
RA3 does not have a corresponding TRISA bit. This pin is always an input regardless of mode.
2009-2016 Microchip Technology Inc.
DS40001365F-page 77
PIC18(L)F1XK22
TABLE 8-2:
Name
ANSEL
INTCON
INTCON2
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Bit 7
Bit 6
ANS7
ANS6
GIE/GIEH PEIE/GIEL
RABPU
INTEDG0
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values on
page
ANS5
ANS4
ANS3
ANS2
ANS1
ANS0
247
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
244
—
TMR0IP
—
RABIP
244
IOCA2
IOCA1
IOCA0
247
LATA2
LATA1
LATA0
247
INTEDG1 INTEDG2
(2)
IOCA
—
—
IOCA5
IOCA4
LATA
—
—
LATA5(1)
LATA4(1)
—
PORTA
—
—
RA5(1)
RA4(1)
RA3(2)
RA2
RA1
RA0
247
SLRCON
—
—
—
—
—
SLRC
SLRB
SLRA
247
TRISA2
TRISA1
TRISA0
247
WPUA2
WPUA1
WPUA0
244
TRISA
WPUA
—
—
—
—
TRISA5
(1)
WPUA5
(1)
TRISA4
WPUA4
IOCA3
(3)
—
(2)
WPUA3
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTA.
Note 1: RA and their associated latch and data direction bits are enabled as I/O pins based on oscillator
configuration; otherwise, they are read as ‘0’.
2: Implemented only when Master Clear functionality is disabled (MCLRE Configuration bit = 0).
3: Unimplemented, read as ‘1’.
DS40001365F-page 78
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
8.2
PORTB, TRISB and LATB
Registers
PORTB is an 4-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., disable the output driver). Clearing a
TRISB bit (= 0) will make the corresponding PORTB
pin an output (i.e., enable the output driver and put the
contents of the output latch on the selected pin).
A mismatch condition will continue to set the RABIF flag
bit. Reading or writing PORTB will end the mismatch
condition and allow the RABIF bit to be cleared. The latch
holding the last read value is not affected by a MCLR nor
Brown-out Reset. After either one of these Resets, the
RABIF flag will continue to be set if a mismatch is present.
Note:
The PORTB Data Latch register (LATB) is also memory
mapped. Read-modify-write operations on the LATB
register read and write the latched output value for
PORTB.
EXAMPLE 8-2:
CLRF
PORTB
CLRF
LATB
MOVLW
0F0h
MOVWF
TRISB
INITIALIZING PORTB
;
;
;
;
;
;
;
;
;
;
Initialize PORTB by
clearing output
data latches
Alternate method
to clear output
data latches
Value used to
initialize data
direction
Set RB as outputs
All PORTB pins are individually configurable as
interrupt-on-change pins. Control bits in the IOCB
register enable (when set) or disable (when clear) the
interrupt function for each pin.
When set, the RABIE bit of the INTCON register
enables interrupts on all pins which also have their
corresponding IOCB bit set. When clear, the RABIE
bit disables all interrupt-on-changes.
Only pins configured as inputs can cause this interrupt
to occur (i.e., any pin configured as an output is
excluded from the interrupt-on-change comparison).
If a change on the I/O pin should occur
when the read operation is being executed
(start of the Q2 cycle), then the RABIF
interrupt flag may not get set. Furthermore,
since a read or write on a port affects all
bits of that port, care must be taken when
using multiple pins in Interrupt-on-Change
mode. Changes on one pin may not be
seen while servicing changes on another
pin.
The interrupt-on-change feature is recommended for
wake-up on key depression operation and operations
where PORTB is only used for the interrupt-on-change
feature. Polling of PORTB is not recommended while
using the interrupt-on-change feature.
All PORTB pins have individually controlled weak
internal pull-up. When set, each bit of the WPUB
register enables the corresponding pin pull-up. When
cleared, the RABPU bit of the INTCON2 register
enables pull-ups on all pins which also have their
corresponding WPUB bit set. When set, the RABPU bit
disables all weak pull-ups. 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.
Note:
On a Power-on Reset, RB are
configured as analog inputs by default and
read as ‘0’.
For enabled interrupt-on-change pins, the values are
compared with the old value latched on the last read of
PORTB. The ‘mismatch’ outputs of the last read are
OR’d together to set the PORTB Change Interrupt flag
bit (RABIF) in the INTCON register.
This interrupt can wake the device from the Sleep
mode, or any of the Idle modes. The user, in the
Interrupt Service Routine, can clear the interrupt in the
following manner:
a)
b)
Any read or write of PORTB to clear the
mismatch condition (except when PORTB is the
source or destination of a MOVFF instruction).
Clear the flag bit, RABIF.
2009-2016 Microchip Technology Inc.
DS40001365F-page 79
PIC18(L)F1XK22
REGISTER 8-6:
PORTB: PORTB REGISTER
R/W-x
R/W-x
R/W-x
R/W-x
U-0
U-0
U-0
U-0
RB7
RB6
RB5
RB4
—
—
—
—
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7-4
RB: PORTB I/O Pin bit
1 = Port pin is >VIH
0 = Port pin is VIH
0 = Port pin is < VIL
REGISTER 8-12:
TRISC: PORTC TRI-STATE REGISTER
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
TRISC7
TRISC6
TRISC5
TRISC4
TRISC3
TRISC2
TRISC1
TRISC0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7-0
x = Bit is unknown
TRISC: PORTC Tri-State Control bits
1 = PORTC pin configured as an input (tri-stated)
0 = PORTC pin configured as an output
DS40001365F-page 84
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 8-13:
LATC: PORTC DATA LATCH REGISTER
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
LATC7
LATC6
LATC5
LATC4
LATC3
LATC2
LATC1
LATC0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7-0
x = Bit is unknown
LATC: RB Port I/O Output Latch Register bits
2009-2016 Microchip Technology Inc.
DS40001365F-page 85
PIC18(L)F1XK22
TABLE 8-5:
Pin
RC0/AN4/C2IN+
RC1/AN5/
C12IN1-
RC2/AN6/
C12IN2-/P1D
RC3/AN7/
C12IN3-/P1C/
PGM
RC4/C2OUT/P1B/
SRNQ
PORTC I/O SUMMARY
Function
TRIS
Setting
I/O
I/O
Type
RC0
0
O
DIG
1
I
ST
AN4
1
I
ANA
A/D input channel 4.
C2IN+
1
I
ANA
Comparators C2 noninverting input.
RC1
0
O
DIG
LATC data output.
1
I
ST
AN5
1
I
ANA
A/D input channel 5.
C12IN1-
1
I
ANA
Comparators C1 and C2 inverting input, channel 1.
RC2
0
O
DIG
LATC data output.
1
I
ST
AN6
1
I
ANA
A/D input channel 6.
C12IN2-
1
I
ANA
Comparators C1 and C2 inverting input, channel 2.
RC7/AN9/SDO
Legend:
PORTC data input.
PORTC data input.
PORTC data input.
P1D
0
O
DIG
ECCP1 Enhanced PWM output, channel D.
0
O
DIG
LATC data output.
1
I
ST
AN7
1
I
ANA
A/D input channel 7.
PORTC data input.
C12IN3-
1
I
ANA
Comparators C1 and C2 inverting input, channel 3.
P1C
0
O
DIG
ECCP1 Enhanced PWM output, channel C.
PGM
x
I
ST
Single-Supply Programming mode entry (ICSP™). Enabled by LVP
Configuration bit; all other pin functions disabled.
RC4
0
O
DIG
LATC data output.
1
I
ST
PORTC data input.
0
O
DIG
Comparator 2 output.
P1B
0
O
DIG
ECCP1 Enhanced PWM output, channel B.
SRNQ
0
O
DIG
SR Latch inverted output
RC5
0
O
DIG
LATC data output.
1
I
ST
PORTC data input.
0
O
DIG
ECCP1 compare or PWM output.
1
I
ST
ECCP1 capture input.
P1A
0
0
DIG
ECCP1 Enhanced PWM output, channel A.
RC6
0
O
DIG
LATC data output.
1
I
ST
AN8
1
I
ANA
A/D input channel 8.
SS
1
I
TTL
Slave select input for SSP (MSSP module)
RC7
0
O
DIG
LATC data output.
1
I
ST
AN9
1
I
ANA
A/D input channel 9.
SDO
0
O
DIG
SPI data output (MSSP module).
CCP1
RC6/AN8/SS
LATC data output.
RC3
C2OUT
RC5/CCP1/P1A
Description
PORTC data input.
PORTC data input.
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).
DS40001365F-page 86
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 8-6:
Name
ANSEL
ANSELH
CCP1CON
SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
ANS7
ANS6
ANS5
ANS4
ANS3
ANS2
ANS1
ANS0
247
—
—
—
—
ANS11
ANS10
ANS9
ANS8
247
P1M1
P1M0
DC1B1
DC1B0
CCP1M3 CCP1M2 CCP1M1 CCP1M0
ECCP1AS
ECCPASE ECCPAS2 ECCPAS1 ECCPAS0 PSSAC1 PSSAC0 PSSBD1
INTCON
GIE/GIEH PEIE/GIEL
246
PSSBD0
246
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
244
INTEDG1
INTEDG2
—
TMR0IP
—
RABIP
244
INTCON2
RABPU
INTEDG0
INTCON3
INT2IP
INT1IP
—
INT2IE
INT1IE
—
INT2IF
INT1IF
244
LATC
LATC7
LATC6
LATC5
LATC4
LATC3
LATC2
LATC1
LATC0
247
RC7
RC6
RC5
RC4
RC3
RC2
RC1
RC0
247
PSTRCON
—
—
—
STRSYNC
STRD
STRC
STRB
STRA
246
VREFCON1
D1EN
D1LPS
DAC1OE
---
---
D1NSS
246
—
—
—
—
—
SLRC
SLRB
SLRA
247
SSPCON1
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
245
TRISC
TRISC7
TRISC6
TRISC5
TRISC4
TRISC3
TRISC2
TRISC1
TRISC0
247
T1CON
RD16
T1RUN
T3CON
RD16
—
PORTC
SLRCON
2009-2016 Microchip Technology Inc.
D1PSS1 D1PSS0
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON
245
T3CKPS1 T3CKPS0
246
T3CCP1 T3SYNC TMR3CS TMR3ON
DS40001365F-page 87
PIC18(L)F1XK22
8.4
Port Analog Control
Some port pins are multiplexed with analog functions
such as the Analog-to-Digital Converter and
comparators. When these I/O pins are to be used as
analog inputs it is necessary to disable the digital input
buffer to avoid excessive current caused by improper
biasing of the digital input. Individual control of the
digital input buffers on pins which share analog
functions is provided by the ANSEL and ANSELH
REGISTER 8-14:
registers. Setting an ANSx bit high will disable the
associated digital input buffer and cause all reads of
that pin to return ‘0’ while allowing analog functions of
that pin to operate correctly.
The state of the ANSx bits has no affect on digital
output functions. A pin with the associated TRISx bit
clear and ANSx bit set will still operate as a digital
output but the Input mode will be analog.
ANSEL: ANALOG SELECT REGISTER
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
ANS7
ANS6
ANS5
ANS4
ANS3
ANS2
ANS1
ANS0
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
bit 7
ANS7: RC3 Analog Select Control bit
1 = Digital input buffer of RC3 is disabled
0 = Digital input buffer of RC3 is enabled
bit 6
ANS6: RC2 Analog Select Control bit
1 = Digital input buffer of RC2 is disabled
0 = Digital input buffer of RC2 is enabled
bit 5
ANS5: RC1 Analog Select Control bit
1 = Digital input buffer of RC1 is disabled
0 = Digital input buffer of RC1 is enabled
bit 4
ANS4: RC0 Analog Select Control bit
1 = Digital input buffer of RC0 is disabled
0 = Digital input buffer of RC0 is enabled
bit 3
ANS3: RA4 Analog Select Control bit
1 = Digital input buffer of RA4 is disabled
0 = Digital input buffer of RA4 is enabled
bit 2
ANS2: RA2 Analog Select Control bit
1 = Digital input buffer of RA2 is disabled
0 = Digital input buffer of RA2 is enabled
bit 1
ANS1: RA1 Analog Select Control bit
1 = Digital input buffer of RA1 is disabled
0 = Digital input buffer of RA1 is enabled
bit 0
ANS0: RA0 Analog Select Control bit
1 = Digital input buffer of RA0 is disabled
0 = Digital input buffer of RA0 is enabled
DS40001365F-page 88
x = Bit is unknown
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 8-15:
ANSELH: ANALOG SELECT HIGH REGISTER
U-0
U-0
U-0
U-0
R/W-1
R/W-1
R/W-1
R/W-1
—
—
—
—
ANS11
ANS10
ANS9
ANS8
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
bit 7-4
Unimplemented: Read as ‘0’
bit 3
ANS11: RB5 Analog Select Control bit
1 = Digital input buffer of RB5 is disabled
0 = Digital input buffer of RB5 is enabled
bit 2
ANS10: RB4 Analog Select Control bit
1 = Digital input buffer of RB4 is disabled
0 = Digital input buffer of RB4 is enabled
bit 1
ANS9: RC7 Analog Select Control bit
1 = Digital input buffer of RC7 is disabled
0 = Digital input buffer of RC7 is enabled
bit 0
ANS8: RC6 Analog Select Control bit
1 = Digital input buffer of RC6 is disabled
0 = Digital input buffer of RC6 is enabled
2009-2016 Microchip Technology Inc.
x = Bit is unknown
DS40001365F-page 89
PIC18(L)F1XK22
8.5
Port Slew Rate Control
The output slew rate of each port is programmable to
select either the standard transition rate or a reduced
transition rate of 0.1 times the standard to minimize
EMI. The reduced transition time is the default slew
rate for all ports.
REGISTER 8-16:
SLRCON: SLEW RATE CONTROL REGISTER
U-0
U-0
U-0
U-0
U-0
R/W-1
R/W-1
R/W-1
—
—
—
—
—
SLRC
SLRB
SLRA
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
bit 7-3
Unimplemented: Read as ‘0’
bit 2
SLRC: PORTC Slew Rate Control bit
1 = All outputs on PORTC slew at 0.1 times the standard rate
0 = All outputs on PORTC slew at the standard rate
bit 1
SLRB: PORTB Slew Rate Control bit
1 = All outputs on PORTB slew at 0.1 times the standard rate
0 = All outputs on PORTB slew at the standard rate
bit 0
SLRA: PORTA Slew Rate Control bit
1 = All outputs on PORTA slew at 0.1 times the standard rate(1)
0 = All outputs on PORTA slew at the standard rate
x = Bit is unknown
Note 1: The slew rate of RA4 defaults to standard rate when the pin is used as CLKOUT.
DS40001365F-page 90
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
9.0
The T0CON register (Register 9-1) controls all aspects
of the module’s operation, including the prescale
selection. It is both readable and writable.
TIMER0 MODULE
The Timer0 module incorporates the following features:
• Software selectable operation as a timer or
counter in both 8-bit or 16-bit modes
• Readable and writable registers
• Dedicated 8-bit, software programmable
prescaler
• Selectable clock source (internal or external)
• Edge select for external clock
• Interrupt-on-overflow
REGISTER 9-1:
A simplified block diagram of the Timer0 module in 8-bit
mode is shown in Figure 9-1. Figure 9-2 shows a
simplified block diagram of the Timer0 module in 16-bit
mode.
T0CON: TIMER0 CONTROL REGISTER
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
TMR0ON
T08BIT
T0CS
T0SE
PSA
T0PS2
T0PS1
T0PS0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
TMR0ON: Timer0 On/Off Control bit
1 = Enables Timer0
0 = Stops Timer0
bit 6
T08BIT: Timer0 8-bit/16-bit Control bit
1 = Timer0 is configured as an 8-bit timer/counter
0 = Timer0 is configured as a 16-bit timer/counter
bit 5
T0CS: Timer0 Clock Source Select bit
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock (CLKOUT)
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
T0PS: 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
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DS40001365F-page 91
PIC18(L)F1XK22
9.1
Timer0 Operation
9.2
Timer0 can operate as either a timer or a counter; the
mode is selected with the T0CS bit of the T0CON
register. In Timer mode (T0CS = 0), the module
increments on every clock by default unless a different
prescaler value is selected (see Section 9.3
“Prescaler”). Timer0 incrementing is inhibited for two
instruction cycles following a TMR0 register write. The
user can work around this by adjusting the value written
to the TMR0 register to compensate for the anticipated
missing increments.
The Counter mode is selected by setting the T0CS bit
(= 1). In this mode, Timer0 increments either on every
rising or falling edge of the T0CKI pin. The
incrementing edge is determined by the Timer0 Source
Edge Select bit, T0SE of the T0CON register; clearing
this bit selects the rising edge. Restrictions on the
external clock input are discussed below.
Timer0 Reads and Writes in
16-Bit Mode
TMR0H is not the actual high byte of Timer0 in 16-bit
mode; it is actually a buffered version of the real high
byte of Timer0 which is neither directly readable nor
writable (refer to Figure 9-2). TMR0H is updated with
the contents of the high byte of Timer0 during a read of
TMR0L. This provides the ability to read all 16 bits of
Timer0 without the need to verify that the read of the
high and low byte were valid. Invalid reads could
otherwise occur due to a rollover between successive
reads of the high and low byte.
Similarly, a write to the high byte of Timer0 must also
take place through the TMR0H Buffer register. Writing
to TMR0H does not directly affect Timer0. Instead, the
high byte of Timer0 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.
An external clock source can be used to drive Timer0;
however, it must meet certain requirements (see
Table 26-17) to ensure that the external clock can be
synchronized with the internal phase clock (TOSC).
There is a delay between synchronization and the
onset of incrementing the timer/counter.
FIGURE 9-1:
TIMER0 BLOCK DIAGRAM (8-BIT MODE)
FOSC/4
0
1
1
T0CKI pin
T0SE
T0CS
T0PS
PSA
Note:
Programmable
Prescaler
0
Sync with
Internal
Clocks
TMR0L
Set
TMR0IF
on Overflow
(2 TCY Delay)
8
3
8
Internal Data Bus
Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI. TMR0 Prescaler is set to maximum (1:256),
but on Reset is not assigned to the timer.
DS40001365F-page 92
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 9-2:
TIMER0 BLOCK DIAGRAM (16-BIT MODE)
FOSC/4
0
1
Sync with
Internal
Clocks
1
Programmable
Prescaler
T0CKI pin
T0SE
T0CS
0
TMR0
High Byte
TMR0L
8
Set
TMR0IF
on Overflow
(2 TCY Delay)
3
Read TMR0L
T0PS
Write TMR0L
PSA
8
8
TMR0H
8
8
Internal Data Bus
Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI. TMR0 Prescaler is set to maximum (1:256), but on Reset
is not assigned to the timer.
Note:
9.3
9.3.1
Prescaler
An 8-bit counter is available as a prescaler for the Timer0
module. The prescaler is not directly readable or writable;
its value is set by the PSA and T0PS bits of the
T0CON register which determine the prescaler
assignment and prescale ratio.
Clearing the PSA bit assigns the prescaler to the
Timer0 module. When the prescaler is assigned,
prescale values from 1:2 through 1:256 in integer
power-of-2 increments are selectable.
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (e.g., CLRF TMR0, MOVWF
TMR0, BSF TMR0, etc.) clear the prescaler count.
Note:
Writing to TMR0 when the prescaler is
assigned to Timer0 will clear the prescaler
count but will not change the prescaler
assignment.
TABLE 9-1:
Name
INTCON
PORTA
SWITCHING PRESCALER
ASSIGNMENT
The prescaler assignment is fully under software
control and can be changed “on-the-fly” during program
execution.
9.4
Timer0 Interrupt
The TMR0 interrupt is generated when the TMR0
register overflows from FFh to 00h in 8-bit mode, or
from FFFFh to 0000h in 16-bit mode. This overflow sets
the TMR0IF flag bit. The interrupt can be masked by
clearing the TMR0IE bit of the INTCON register. Before
re-enabling the interrupt, the TMR0IF bit must be
cleared by software in the Interrupt Service Routine.
Since Timer0 is shut down in Sleep mode, the TMR0
interrupt cannot awaken the processor from Sleep.
REGISTERS ASSOCIATED WITH TIMER0
Bit 7
Bit 6
Bit 5
GIE/GIEH PEIE/GIEL TMR0IE
RA7
RA6
RA5
TMR0H
Timer0 Register, High Byte
TMR0L
Timer0 Register, Low Byte
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
RA4
RA3
RA2
RA1
RA0
248
246
246
TRISA
—
—
TRISA5
TRISA4
—(1)
TRISA2
TRISA1
TRISA0
248
T0CON
TMR0ON
T08BIT
T0CS
T0SE
PSA
T0PS2
T0PS1
T0PS0
246
Legend: Shaded cells are not used by Timer0.
Note:
Unimplemented, read as’1’.
2009-2016 Microchip Technology Inc.
DS40001365F-page 93
PIC18(L)F1XK22
10.0
TIMER1 MODULE
The Timer1 timer/counter module incorporates the
following features:
• Software selectable operation as a 16-bit timer or
counter
• Readable and writable 8-bit registers (TMR1H
and TMR1L)
• Selectable internal or external clock source and
Timer1 oscillator options
• Interrupt-on-overflow
• Reset on CCP Special Event Trigger
• Device clock status flag (T1RUN)
REGISTER 10-1:
A simplified block diagram of the Timer1 module is
shown in Figure 10-1. A block diagram of the module’s
operation in Read/Write mode is shown in Figure 10-2.
Timer1 can also be used to provide Real-Time Clock
(RTC) functionality to applications with only a minimal
addition of external components and code overhead.
Timer1 is controlled through the T1CON Control
register (Register 10-1). It also contains the Timer1
Oscillator Enable bit (T1OSCEN). Timer1 can be
enabled or disabled by setting or clearing control bit,
TMR1ON of the T1CON register.
T1CON: TIMER1 CONTROL REGISTER
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 = Main system clock is derived from Timer1 oscillator
0 = Main system clock is derived from another source
bit 5-4
T1CKPS: 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 the T13CKI pin (on the rising edge)
0 = Internal clock (FOSC/4)
bit 0
TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1
DS40001365F-page 94
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
10.1
Timer1 Operation
Timer1 can operate in one of the following modes:
• Timer
• Synchronous Counter
• Asynchronous Counter
The operating mode is determined by the clock select
bit, TMR1CS of the T1CON register. When TMR1CS is
cleared (= 0), Timer1 increments on every internal
instruction cycle (FOSC/4). When the bit is set, Timer1
increments on every rising edge of either the Timer1
external clock input or the Timer1 oscillator, if enabled.
When the Timer1 oscillator is enabled, the digital
circuitry associated with the OSC1 and OSC2 pins is
disabled. This means the values of TRISA are
ignored and the pins are read as ‘0’.
FIGURE 10-1:
TIMER1 BLOCK DIAGRAM
Timer1 Oscillator
Timer1 Clock Input
On/Off
OSC1/T13CKI
1
1
FOSC/4
Internal
Clock
OSC2
Synchronize
Prescaler
1, 2, 4, 8
Detect
0
0
2
INTOSC
Without CLKOUT
Sleep Input
TMR1CS
Timer1
On/Off
T1OSCEN(1)
T1CKPS
T1SYNC
TMR1ON
Clear TMR1
(CCP Special Event Trigger)
TMR1L
TMR1
High Byte
Set
TMR1IF
on Overflow
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
2009-2016 Microchip Technology Inc.
DS40001365F-page 95
PIC18(L)F1XK22
FIGURE 10-2:
TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
Timer1 Clock Input
Timer1 Oscillator
1
OSC1/T13CKI
1
FOSC/4
Internal
Clock
OSC2
Synchronize
Prescaler
1, 2, 4, 8
0
Detect
0
2
INTOSC
Without CLKOUT
Sleep Input
TMR1CS
T1OSCEN(1)
Timer1
On/Off
T1CKPS
T1SYNC
TMR1ON
Clear TMR1
(CCP Special Event Trigger)
TMR1
High Byte
TMR1L
8
Set
TMR1IF
on Overflow
Read TMR1L
Write TMR1L
8
8
TMR1H
8
8
Internal Data Bus
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
DS40001365F-page 96
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
10.2
Timer1 16-Bit Read/Write Mode
Timer1 can be configured for 16-bit reads and writes
(see Figure 10-2). When the RD16 control bit of the
T1CON register 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. This
provides the user with the ability to accurately read all
16 bits of Timer1 without the need to determine
whether a read of the high byte, followed by a read of
the low byte, has become invalid due to a rollover or
carry between reads.
Writing to TMR1H does not directly affect Timer1.
Instead, the high byte of Timer1 is updated with the
contents of TMR1H when a write occurs to TMR1L.
This allows all 16 bits of Timer1 to be updated 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.
10.3
Clock Source Selection
The TMR1CS bit of the T1CON register is used to select
the clock source. When TMR1CS = 0, the clock source
is FOSC/4. When TMR1CS = 1, the clock source is
supplied externally.
Clock
Source
T1OSCEN
FOSC
Mode
TMR1CS
FOSC/4
x
xxx
0
T1CKI pin
0
xxx
1
T1LPOSC
1
LP or
INTOSCIO
1
10.3.1
If an external clock oscillator is needed (and the
microcontroller is using the INTOSC without CLKOUT),
Timer1 can use the LP oscillator as a clock source.
Note:
•
•
•
•
Note:
10.4
Timer1 enabled after POR
Write to TMR1H or TMR1L
Timer1 is disabled
Timer1 is disabled (TMR1ON 0)
when T1CKI is high then Timer1 is
enabled (TMR1ON= 1) when T1CKI
is low.
See Figure 9-2.
Timer1 Oscillator
An on-chip crystal oscillator circuit is incorporated
between pins OSC1 (input) and OSC2 (amplifier output).
It is enabled by setting the Timer1 Oscillator Enable bit,
T1OSCEN of the T1CON register. The oscillator is a
low-power circuit rated for 32 kHz crystals. It will
continue to run during all power-managed modes. The
circuit for a typical LP oscillator is shown in Figure 10-3.
Table 10-1 shows the capacitor selection for the Timer1
oscillator.
The Timer1 oscillator is shared with the system LP
oscillator. Thus, Timer1 can use this mode only when
the primary system clock is derived from the internal
oscillator or when the oscillator is in the LP mode. The
user must provide a software time delay to ensure
proper oscillator start-up.
FIGURE 10-3:
INTERNAL CLOCK SOURCE
XTAL
32.768 kHz
When the external clock source is selected, the Timer1
module may work as a timer or a counter.
2009-2016 Microchip Technology Inc.
PIC® MCU
OSC1
EXTERNAL CLOCK SOURCE
When counting, Timer1 is incremented on the rising
edge of the external clock input T1CKI. In addition, the
Counter mode clock can be synchronized to the
microcontroller system clock or run asynchronously.
EXTERNAL
COMPONENTS FOR THE
TIMER1 LP OSCILLATOR
C1
27 pF
When the internal clock source is selected the
TMR1H:TMR1L register pair will increment on multiples
of FOSC as determined by the Timer1 prescaler.
10.3.2
In Counter mode, a falling edge must be
registered by the counter prior to the first
incrementing rising edge after any one or
more of the following conditions:
OSC2
C2
27 pF
Note:
See the Notes with Table 10-1 for additional
information about capacitor selection.
DS40001365F-page 97
PIC18(L)F1XK22
TABLE 10-1:
CAPACITOR SELECTION FOR
THE TIMER OSCILLATOR
Osc Type
Freq.
C1
C2
LP
32 kHz
27 pF(1)
27 pF(1)
Note 1: Microchip suggests these values only 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.
10.5
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 the TMR1IF interrupt flag bit of the
PIR1 register. This interrupt can be enabled or disabled
by setting or clearing the TMR1IE Interrupt Enable bit
of the PIE1 register.
10.6
Resetting Timer1 Using the CCP
Special Event Trigger
If either of the CCP modules is configured to use Timer1
and generate a Special Event Trigger in Compare mode
(CCP1M or CCP2M = 1011), this signal will
reset Timer1. The trigger from CCP2 will also start an
A/D conversion if the A/D module is enabled (see
Section 13.3.4 “Special Event Trigger” for more
information).
10.7
Using Timer1 as a Real-Time Clock
Adding an external LP oscillator to Timer1 (such as the
one described in Section 10.4 “Timer1 Oscillator”
above) gives users the option to include RTC
functionality to their applications. This is accomplished
with an inexpensive watch crystal to provide an
accurate time base and several lines of application
code to calculate the time. When operating in Sleep
mode and using a battery or supercapacitor as a power
source, it can completely eliminate the need for a
separate RTC device and battery backup.
The application code routine, RTCisr, shown in
Example 10-1, demonstrates a simple method to
increment a counter at one-second intervals using an
Interrupt Service Routine. Incrementing the TMR1
register pair to overflow triggers the interrupt and calls
the routine, which increments the seconds counter by
one; additional counters for minutes and hours are
incremented on overflows of the less significant
counters.
Since the register pair is 16-bit wide, a 32.768 kHz
clock source will take two seconds to count up to
overflow. To force the overflow at the required
one-second intervals, it is necessary to pre-load it; the
simplest method is to set the MSb of TMR1H with a
BSF instruction. Note that the TMR1L register is never
preloaded or altered; doing so may introduce
cumulative error over many cycles.
For this method to be accurate, Timer1 must operate in
Asynchronous mode and the Timer1 overflow interrupt
must be enabled (PIE1 = 1), as shown in the
routine, RTCinit. The Timer1 oscillator must also be
enabled and running at all times.
The module must be configured as either a timer or a
synchronous counter to take advantage of this feature.
When used this way, the CCPRH:CCPRL register pair
effectively becomes a period register for Timer1.
If Timer1 is running in Asynchronous Counter mode,
this Reset operation may not work.
In the event that a write to Timer1 coincides with a
special Event Trigger, the write operation will take
precedence.
Note:
The Special Event Triggers from the
CCP2 module will not set the TMR1IF
interrupt flag bit of the PIR1 register.
DS40001365F-page 98
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
EXAMPLE 10-1:
IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE
RTCinit
MOVLW
MOVWF
CLRF
MOVLW
MOVWF
CLRF
CLRF
MOVLW
MOVWF
BSF
RETURN
80h
TMR1H
TMR1L
b’00001111’
T1CON
secs
mins
.12
hours
PIE1, TMR1IE
BSF
BCF
INCF
MOVLW
CPFSGT
RETURN
CLRF
INCF
MOVLW
CPFSGT
RETURN
CLRF
INCF
MOVLW
CPFSGT
RETURN
CLRF
RETURN
TMR1H, 7
PIR1, TMR1IF
secs, F
.59
secs
; Preload TMR1 register pair
; for 1 second overflow
; Configure for external clock,
; Asynchronous operation, external oscillator
; Initialize timekeeping registers
;
; Enable Timer1 interrupt
RTCisr
TABLE 10-2:
Name
INTCON
secs
mins, F
.59
mins
mins
hours, F
.23
hours
;
;
;
;
Preload for 1 sec overflow
Clear interrupt flag
Increment seconds
60 seconds elapsed?
;
;
;
;
No, done
Clear seconds
Increment minutes
60 minutes elapsed?
;
;
;
;
No, done
clear minutes
Increment hours
24 hours elapsed?
; No, done
; Reset hours
; Done
hours
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Bit 7
Bit 6
GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
PIR1
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
TMR1H
Timer1 Register, High Byte
TMR1L
246
Timer1 Register, Low Byte
TRISA
—
—
T1CON
RD16
T1RUN
TRISA5
TRISA4
—(1)
246
TRISA2
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC
TRISA1
TRISA0
248
TMR1CS
TMR1ON
246
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer1 module.
Note 1: Unimplemented, read as’1’.
2009-2016 Microchip Technology Inc.
DS40001365F-page 99
PIC18(L)F1XK22
11.0
TIMER2 MODULE
11.1
The Timer2 module timer incorporates the following
features:
• 8-bit timer and period registers (TMR2 and PR2,
respectively)
• Readable and writable (both registers)
• Software programmable prescaler (1:1, 1:4 and
1:16)
• Software programmable postscaler (1:1 through
1:16)
• Interrupt on TMR2-to-PR2 match
• Optional use as the shift clock for the MSSP
module
The module is controlled through the T2CON register
(Register 11-1), which enables or disables the timer
and configures the prescaler and postscaler. Timer2
can be shut off by clearing control bit, TMR2ON of the
T2CON register, to minimize power consumption.
A simplified block diagram of the module is shown in
Figure 11-1.
Timer2 Operation
In normal operation, TMR2 is incremented from 00h on
each clock (FOSC/4). A 4-bit counter/prescaler on the
clock input gives direct input, divide-by-4 and
divide-by-16 prescale options; these are selected by
the prescaler control bits, T2CKPS of the T2CON
register. The value of TMR2 is compared to that of the
period register, PR2, on each clock cycle. When the
two values match, the comparator generates a match
signal as the timer output. This signal also resets the
value of TMR2 to 00h on the next cycle and drives the
output counter/postscaler (see Section 11.2 “Timer2
Interrupt”).
The TMR2 and PR2 registers are both directly readable
and writable. The TMR2 register is cleared on any
device Reset, whereas the PR2 register initializes to
FFh. Both the prescaler and postscaler counters are
cleared on the following events:
• a write to the TMR2 register
• a write to the T2CON register
• any device Reset (Power-on Reset, MCLR Reset,
Watchdog Timer Reset or Brown-out Reset)
TMR2 is not cleared when T2CON is written.
REGISTER 11-1:
T2CON: TIMER2 CONTROL REGISTER
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
T2OUTPS3
T2OUTPS2
T2OUTPS1
T2OUTPS0
TMR2ON
T2CKPS1
T2CKPS0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
Unimplemented: Read as ‘0’
bit 6-3
T2OUTPS: Timer2 Output Postscale Select bits
0000 = 1:1 Postscale
0001 = 1:2 Postscale
•
•
•
1111 = 1:16 Postscale
bit 2
TMR2ON: Timer2 On bit
1 = Timer2 is on
0 = Timer2 is off
bit 1-0
T2CKPS: Timer2 Clock Prescale Select bits
00 = Prescaler is 1
01 = Prescaler is 4
1x = Prescaler is 16
DS40001365F-page 100
x = Bit is unknown
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
11.2
Timer2 Interrupt
11.3
Timer2 can also generate an optional device interrupt.
The Timer2 output signal (TMR2-to-PR2 match)
provides
the
input
for
the
4-bit
output
counter/postscaler. This counter generates the TMR2
match interrupt flag which is latched in TMR2IF of the
PIR1 register. The interrupt is enabled by setting the
TMR2 Match Interrupt Enable bit, TMR2IE of the PIE1
register.
Timer2 Output
The unscaled output of TMR2 is available primarily to
the CCP modules, where it is used as a time base for
operations in PWM mode.
Timer2 can be optionally used as the shift clock source
for the MSSP module operating in SPI mode.
Additional information is provided in Section 14.0
“Master Synchronous Serial Port (MSSP) Module”.
A range of 16 postscale options (from 1:1 through 1:16
inclusive) can be selected with the postscaler control
bits, T2OUTPS of the T2CON register.
FIGURE 11-1:
TIMER2 BLOCK DIAGRAM
4
T2OUTPS
1:1 to 1:16
Postscaler
Set TMR2IF
2
T2CKPS
TMR2/PR2
Match
Reset
1:1, 1:4, 1:16
Prescaler
FOSC/4
TMR2
TMR2 Output
(to PWM or MSSP)
Comparator
8
PR2
8
8
Internal Data Bus
TABLE 11-1:
Name
REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER
Bit 7
Bit 6
INTCON GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
PIR1
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
PR2
Timer2 Period Register
TMR2
T2CON
246
Timer2 Register
—
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON
246
T2CKPS1 T2CKPS0
246
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer2 module.
2009-2016 Microchip Technology Inc.
DS40001365F-page 101
PIC18(L)F1XK22
12.0
TIMER3 MODULE
The Timer3 module timer/counter incorporates these
features:
• Software selectable operation as a 16-bit timer or
counter
• Readable and writable 8-bit registers (TMR3H
and TMR3L)
• Selectable clock source (internal or external) with
device clock or Timer1 oscillator internal options
• Interrupt-on-overflow
• Module Reset on CCP Special Event Trigger
REGISTER 12-1:
A simplified block diagram of the Timer3 module is
shown in Figure 12-1. A block diagram of the module’s
operation in Read/Write mode is shown in Figure 12-2.
The Timer3 module is controlled through the T3CON
register (Register 12-1). It also selects the clock source
options for the CCP modules (see Section 13.1.1
“CCP Module and Timer Resources” for more
information).
T3CON: TIMER3 CONTROL REGISTER
R/W-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
RD16
—
T3CKPS1
T3CKPS0
T3CCP1
T3SYNC
TMR3CS
TMR3ON
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
RD16: 16-bit Read/Write Mode Enable bit
1 = Enables register read/write of Timer3 in one 16-bit operation
0 = Enables register read/write of Timer3 in two 8-bit operations
bit 6
Unimplemented: Read as ‘0’
bit 5-4
T3CKPS: Timer3 Input Clock Prescale Select bits
11 = 1:8 Prescale value
10 = 1:4 Prescale value
01 = 1:2 Prescale value
00 = 1:1 Prescale value
bit 3
T3CCP1: Timer3 and Timer1 to CCP1 Enable bits
1 = Timer3 is the clock source for compare/capture of ECCP1
0 = Timer1 is the clock source for compare/capture of ECCP1
bit 2
T3SYNC: Timer3 External Clock Input Synchronization Control bit
(Not usable if the device clock comes from Timer1/Timer3.)
When TMR3CS = 1:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
When TMR3CS = 0:
This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0.
bit 1
TMR3CS: Timer3 Clock Source Select bit
1 = External clock input from Timer1 oscillator or T13CKI (on the rising edge after the first
falling edge)
0 = Internal clock (FOSC/4)
bit 0
TMR3ON: Timer3 On bit
1 = Enables Timer3
0 = Stops Timer3
DS40001365F-page 102
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
12.1
Timer3 Operation
Timer3 can operate in one of three modes:
• Timer
• Synchronous Counter
• Asynchronous Counter
The operating mode is determined by the clock select
bit, TMR3CS of the T3CON register. When TMR3CS is
cleared (= 0), Timer3 increments on every internal
instruction cycle (FOSC/4). When the bit is set, Timer3
increments on every rising edge of the Timer1 external
clock input or the Timer1 oscillator, if enabled.
As with Timer1, the digital circuitry associated with the
OSC1 and OSC2 pins is disabled when the Timer1
oscillator is enabled. This means the values of
TRISA are ignored and the pins are read as ‘0’.
FIGURE 12-1:
TIMER3 BLOCK DIAGRAM
Timer1 Oscillator
Timer1 Clock Input
1
OSC1/T13CKI
1
FOSC/4
Internal
Clock
OSC2
Synchronize
Prescaler
1, 2, 4, 8
Detect
0
0
2
INTOSC
Without CLKOUT
Sleep Input
TMR3CS
Timer3
On/Off
T1OSCEN(1)
T3CKPS
T3SYNC
TMR3ON
CCP1 Special Event Trigger
CCP1 Select from T3CON
Clear TMR3
TMR3L
Set
TMR3IF
on Overflow
TMR3
High Byte
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
2009-2016 Microchip Technology Inc.
DS40001365F-page 103
PIC18(L)F1XK22
FIGURE 12-2:
TIMER3 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
Timer1 Clock Input
Timer1 Oscillator
1
OSC1/T1OSI
1
FOSC/4
Internal
Clock
OSC2
Synchronize
Prescaler
1, 2, 4, 8
Detect
0
0
2
INTOSC
Without CLKOUT
Sleep Input
TMR3CS
Timer3
On/Off
T1OSCEN(1)
T3CKPS
T3SYNC
TMR3ON
CCP1 Special Event Trigger
CCP1 Select from T3CON
Clear TMR3
Set
TMR3IF
on Overflow
TMR3
High Byte
TMR3L
8
Read TMR1L
Write TMR1L
8
8
TMR3H
8
8
Internal Data Bus
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
DS40001365F-page 104
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
12.2
Timer3 16-Bit Read/Write Mode
12.4
Timer3 Interrupt
Timer3 can be configured for 16-bit reads and writes
(see Figure 12-2). When the RD16 control bit of the
T3CON register is set, the address for TMR3H is
mapped to a buffer register for the high byte of Timer3.
A read from TMR3L will load the contents of the high
byte of Timer3 into the Timer3 High Byte Buffer register.
This provides the user with the ability to accurately read
all 16 bits of Timer1 without having to determine
whether a read of the high byte, followed by a read of
the low byte, has become invalid due to a rollover
between reads.
The TMR3 register pair (TMR3H:TMR3L) increments
from 0000h to FFFFh and overflows to 0000h. The
Timer3 interrupt, if enabled, is generated on overflow
and is latched in interrupt flag bit, TMR3IF of the PIR2
register. This interrupt can be enabled or disabled by
setting or clearing the Timer3 Interrupt Enable bit,
TMR3IE of the PIE2 register.
A write to the high byte of Timer3 must also take place
through the TMR3H Buffer register. The Timer3 high
byte is updated with the contents of TMR3H when a
write occurs to TMR3L. This allows a user to write all
16 bits to both the high and low bytes of Timer3 at once.
If CCP1 module is configured to use Timer3 and to
generate a Special Event Trigger in Compare mode
(CCP1M), this signal will reset Timer3. It will also
start an A/D conversion if the A/D module is enabled
(see Section 16.2.8 “Special Event Trigger” for more
information).
The high byte of Timer3 is not directly readable or
writable in this mode. All reads and writes must take
place through the Timer3 High Byte Buffer register.
Writes to TMR3H do not clear the Timer3 prescaler.
The prescaler is only cleared on writes to TMR3L.
12.3
Using the Timer1 Oscillator as the
Timer3 Clock Source
The Timer1 internal oscillator may be used as the clock
source for Timer3. The Timer1 oscillator is enabled by
setting the T1OSCEN bit of the T1CON register. To use
it as the Timer3 clock source, the TMR3CS bit must
also be set. As previously noted, this also configures
Timer3 to increment on every rising edge of the
oscillator source.
12.5
Resetting Timer3 Using the CCP
Special Event Trigger
The module must be configured as either a timer or
synchronous counter to take advantage of this feature.
When used this way, the CCPR1H:CCPR1L register
pair effectively becomes a period register for Timer3.
If Timer3 is running in Asynchronous Counter mode,
the Reset operation may not work.
In the event that a write to Timer3 coincides with a
Special Event Trigger from a CCP module, the write will
take precedence.
The Timer1 oscillator is described in Section 10.0
“Timer1 Module”.
TABLE 12-1:
Name
INTCON
REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER
Bit 7
Bit 6
GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR2
OSCFIP
C1IP
C2IP
EEIP
BCLIP
—
TMR3IP
—
248
PIE2
OSCFIE
C1IE
C2IE
EEIE
BCLIE
—
TMR3IE
—
248
PIR2
OSCFIF
C1IF
C2IF
EEIF
BCLIF
—
TMR3IF
—
248
TMR3H
Timer3 Register, High Byte
TMR3L
247
Timer3 Register, Low Byte
TRISA
—
—
T1CON
RD16
T1RUN
T3CON
RD16
—
TRISA5
TRISA4
—(1)
247
TRISA1
TRISA0
248
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC
TMR1CS
TMR1ON
246
T3CKPS1 T3CKPS0
TMR3CS
TMR3ON
247
T3CCP1
TRISA2
T3SYNC
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer3 module.
Note 1: Unimplemented, read as ‘1’.
2009-2016 Microchip Technology Inc.
DS40001365F-page 105
PIC18(L)F1XK22
13.0
CCP1 is implemented as a standard CCP module with
enhanced PWM capabilities. These include:
ENHANCED
CAPTURE/COMPARE/PWM
(ECCP) MODULE
PIC18(L)F1XK22
devices
have
one
ECCP
(Capture/Compare/PWM) module. The module
contains a 16-bit register which can operate as a 16-bit
Capture register, a 16-bit Compare register or a PWM
Master/Slave Duty Cycle register.
REGISTER 13-1:
•
•
•
•
•
Provision for two or four output channels
Output steering
Programmable polarity
Programmable dead-band control
Automatic shutdown and restart
The enhanced features are discussed in detail in
Section 13.4 “PWM (Enhanced Mode)”.
CCP1CON: ENHANCED CAPTURE/COMPARE/PWM CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
P1M1
P1M0
DC1B1
DC1B0
CCP1M3
CCP1M2
CCP1M1
CCP1M0
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
P1M: Enhanced PWM Output Configuration bits
If CCP1M = 00, 01, 10:
xx = P1A assigned as Capture/Compare input/output; P1B, P1C, P1D assigned as port pins
If CCP1M = 11:
00 = Single output: P1A, P1B, P1C and P1D controlled by steering (See Section 13.4.7 “Pulse Steering
Mode”).
01 = Full-bridge output forward: P1D modulated; P1A active; P1B, P1C inactive
10 = Half-bridge output: P1A, P1B modulated with dead-band control; P1C, P1D assigned as port pins
11 = Full-bridge output reverse: P1B modulated; P1C active; P1A, P1D inactive
bit 5-4
DC1B: PWM Duty Cycle bit 1 and bit 0
Capture mode:
Unused.
Compare mode:
Unused.
PWM mode:
These bits are the two LSbs of the 10-bit PWM duty cycle. The eight MSbs of the duty cycle are found in
CCPR1L.
bit 3-0
CCP1M: Enhanced CCP Mode Select bits
0000 = Capture/Compare/PWM off (resets ECCP module)
0001 = Reserved
0010 = Compare mode, toggle output on match
0011 = Reserved
0100 = Capture mode, every falling edge
0101 = Capture mode, every rising edge
0110 = Capture mode, every 4th rising edge
0111 = Capture mode, every 16th rising edge
1000 = Compare mode, initialize CCP1 pin low, set output on compare match (set CCP1IF)
1001 = Compare mode, initialize CCP1 pin high, clear output on compare match (set CCP1IF)
1010 = Compare mode, generate software interrupt only, CCP1 pin reverts to I/O state
1011 = Compare mode, trigger special event (ECCP resets TMR1 or TMR3, start A/D conversion, sets
CC1IF bit)
1100 = PWM mode; P1A, P1C active-high; P1B, P1D active-high
1101 = PWM mode; P1A, P1C active-high; P1B, P1D active-low
1110 = PWM mode; P1A, P1C active-low; P1B, P1D active-high
1111 = PWM mode; P1A, P1C active-low; P1B, P1D active-low
DS40001365F-page 106
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
In addition to the expanded range of modes available
through the CCP1CON register and ECCP1AS
register, the ECCP module has two additional registers
associated with Enhanced PWM operation and
auto-shutdown features. They are:
• PWM1CON (Dead-band delay)
• PSTRCON (Output steering)
13.1
ECCP Outputs and Configuration
The enhanced CCP module may have up to four PWM
outputs, depending on the selected operating mode.
These outputs, designated P1A through P1D, are
multiplexed with I/O pins on PORTC. The outputs that
are active depend on the CCP operating mode
selected. The pin assignments are summarized in
Table 13-2.
To configure the I/O pins as PWM outputs, the proper
PWM mode must be selected by setting the P1M
and CCP1M bits. The appropriate TRISC
direction bits for the port pins must also be set as
outputs.
13.1.1
CCP MODULE AND TIMER
RESOURCES
The CCP modules utilize Timers 1, 2 or 3, depending
on the mode selected. Timer1 and Timer3 are available
to modules in Capture or Compare modes, while
Timer2 is available for modules in PWM mode.
13.2
Capture Mode
In Capture mode, the CCPR1H:CCPR1L register pair
captures the 16-bit value of the TMR1 or TMR3
registers when an event occurs on the corresponding
CCP1 pin. An event is defined as one of the following:
•
•
•
•
Every falling edge
Every rising edge
Every 4th rising edge
Every 16th rising edge
The event is selected by the mode select bits,
CCP1M of the CCP1CON register. When a
capture is made, the interrupt request flag bit, CCP1IF,
is set; it must be cleared by software. If another capture
occurs before the value in register CCPR1 is read, the
old captured value is overwritten by the new captured
value.
13.2.1
CCP PIN CONFIGURATION
In Capture mode, the appropriate CCP1 pin should be
configured as an input by setting the corresponding
TRIS direction bit.
Note:
13.2.2
If the CCP1 pin is configured as an output,
a write to the port can cause a capture
condition.
TIMER1/TIMER3 MODE SELECTION
CCP/ECCP Mode
Timer Resource
Capture
Timer1 or Timer3
The timers that are to be used with the capture feature
(Timer1 and/or Timer3) must be running in Timer mode or
Synchronized Counter mode. In Asynchronous Counter
mode, the capture operation may not work. The timer to
be used with each CCP module is selected in the T3CON
register (see Section 13.1.1 “CCP Module and Timer
Resources”).
Compare
Timer1 or Timer3
13.2.3
PWM
Timer2
TABLE 13-1:
CCP MODE – TIMER
RESOURCE
The assignment of a particular timer to a module is
determined by the Timer-to-CCP enable bits in the
T3CON register (Register 12-1). The interactions
between the two modules are summarized in
Figure 13-1. In Asynchronous Counter mode, the
capture operation will not work reliably.
2009-2016 Microchip Technology Inc.
SOFTWARE INTERRUPT
When the Capture mode is changed, a false capture
interrupt may be generated. The user should keep the
CCP1IE interrupt enable bit clear to avoid false
interrupts. The interrupt flag bit, CCP1IF, should also
be cleared following any such change in operating
mode.
DS40001365F-page 107
PIC18(L)F1XK22
13.2.4
CCP PRESCALER
There are four prescaler settings in Capture mode; they
are specified as part of the operating mode selected by
the mode select bits (CCP1M). Whenever the
CCP module is turned off or Capture mode is disabled,
the prescaler counter is cleared. This means that any
Reset will clear the prescaler counter.
Switching from one capture prescaler to another may
generate an interrupt. Also, the prescaler counter will
not be cleared; therefore, the first capture may be from
a non-zero prescaler. Example 13-1 shows the
recommended method for switching between capture
prescalers. This example also clears the prescaler
counter and will not generate the “false” interrupt.
EXAMPLE 13-1:
CLRF
MOVLW
MOVWF
CHANGING BETWEEN
CAPTURE PRESCALERS
CCP1CON
; Turn CCP module off
NEW_CAPT_PS ; Load WREG with the
; new prescaler mode
; value and CCP ON
CCP1CON
; Load CCP1CON with
; this value
FIGURE 13-1:
CAPTURE MODE OPERATION BLOCK DIAGRAM
TMR3H
Set CCP1IF
T3CCP1
CCP1 pin
Prescaler
1, 4, 16
and
Edge Detect
CCP1CON
Q1:Q4
DS40001365F-page 108
4
TMR3
Enable
CCPR1H
T3CCP1
TMR3L
CCPR1L
TMR1
Enable
TMR1H
TMR1L
4
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
13.3
13.3.2
Compare Mode
TIMER1/TIMER3 MODE SELECTION
In Compare mode, the 16-bit CCPR1 register value is
constantly compared against either the TMR1 or TMR3
register pair value. When a match occurs, the CCP1
pin can be:
Timer1 and/or Timer3 must be running in Timer mode
or Synchronized Counter mode if the CCP module is
using the compare feature. In Asynchronous Counter
mode, the compare operation will not work reliably.
•
•
•
•
13.3.3
Driven high
Driven low
Toggled (high-to-low or low-to-high)
Remain unchanged (that is, reflects the state of
the I/O latch)
The action on the pin is based on the value of the mode
select bits (CCP1M). At the same time, the
interrupt flag bit, CCP1IF, is set.
13.3.1
CCP PIN CONFIGURATION
The user must configure the CCP1 pin as an output by
clearing the appropriate TRIS bit.
Note:
Clearing the CCP1CON register will force
the CCP1 compare output latch
(depending on device configuration) to the
default low level. This is not the PORTC
I/O DATA latch.
FIGURE 13-2:
SOFTWARE INTERRUPT MODE
When the Generate Software Interrupt mode is chosen
(CCP1M = 1010), the CCP1 pin is not affected.
Only the CCP1IF interrupt flag is affected.
13.3.4
SPECIAL EVENT TRIGGER
The CCP module is equipped with a Special Event
Trigger. This is an internal hardware signal generated
in Compare mode to trigger actions by other modules.
The Special Event Trigger is enabled by selecting
the Compare Special Event Trigger mode
(CCP1M = 1011).
The Special Event Trigger resets the timer register pair
for whichever timer resource is currently assigned as the
module’s time base. This allows the CCPR1 registers to
serve as a programmable period register for either timer.
The Special Event Trigger can also start an A/D
conversion. In order to do this, the A/D converter must
already be enabled.
COMPARE MODE OPERATION BLOCK DIAGRAM
0
TMR1H
TMR1L
1
TMR3H
TMR3L
Special Event Trigger
(Timer1/Timer3 Reset, A/D Trigger)
T3CCP1
Set CCP1IF
Comparator
CCPR1H
CCPR1L
Compare
Match
CCP1 pin
Output
Logic
4
S
Q
R
TRIS
Output Enable
CCP1CON
2009-2016 Microchip Technology Inc.
DS40001365F-page 109
PIC18(L)F1XK22
13.4
The PWM outputs are multiplexed with I/O pins and are
designated P1A, P1B, P1C and P1D. The polarity of the
PWM pins is configurable and is selected by setting the
CCP1M bits in the CCP1CON register appropriately.
PWM (Enhanced Mode)
The Enhanced PWM mode can generate a PWM signal
on up to four different output pins with up to 10-bits of
resolution. It can do this through four different PWM
output modes:
•
•
•
•
Table 13-1 shows the pin assignments for each
Enhanced PWM mode.
Single PWM
Half-Bridge PWM
Full-Bridge PWM, Forward mode
Full-Bridge PWM, Reverse mode
Figure 13-3 shows an example of a simplified block
diagram of the Enhanced PWM module.
To prevent the generation of an
incomplete waveform when the PWM is
first enabled, the ECCP module waits until
the start of a new PWM period before
generating a PWM signal.
Note:
To select an Enhanced PWM mode, the P1M bits of the
CCP1CON register must be set appropriately.
FIGURE 13-3:
EXAMPLE SIMPLIFIED BLOCK DIAGRAM OF THE ENHANCED PWM MODE
Duty Cycle Registers
DC1B
CCP1M
4
P1M
2
CCPR1L
CCP1/P1A
CCP1/P1A
TRIS
CCPR1H (Slave)
P1B
R
Comparator
Output
Controller
Q
P1B
TRIS
P1C
TMR2
(1)
Clear Timer2,
toggle PWM pin and
latch duty cycle
PR2
1:
S
P1D
Comparator
Note
P1C
TRIS
P1D
TRIS
PWM1CON
The 8-bit timer TMR2 register is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler to create the 10-bit
time base.
Note 1: The TRIS register value for each PWM
output must be configured appropriately.
2: Any pin not used by an Enhanced PWM
mode is available for alternate pin
functions.
TABLE 13-2:
EXAMPLE PIN ASSIGNMENTS FOR VARIOUS PWM ENHANCED MODES
ECCP Mode
P1M
Single
00
Half-Bridge
10
CCP1/P1A
Yes
(1)
Yes
P1B
Yes
P1C
(1)
Yes
Yes
(1)
No
P1D
Yes(1)
No
Full-Bridge, Forward
01
Yes
Yes
Yes
Yes
Full-Bridge, Reverse
11
Yes
Yes
Yes
Yes
Note 1:
Outputs are enabled by pulse steering in Single mode. See Register 13-4.
DS40001365F-page 110
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 13-4:
EXAMPLE PWM (ENHANCED MODE) OUTPUT RELATIONSHIPS (ACTIVE-HIGH
STATE)
P1M
Signal
PR2+1
Pulse
Width
0
Period
00
(Single Output)
P1A Modulated
Delay(1)
Delay(1)
P1A Modulated
10
(Half-Bridge)
P1B Modulated
P1A Active
01
(Full-Bridge,
Forward)
P1B Inactive
P1C Inactive
P1D Modulated
P1A Inactive
11
(Full-Bridge,
Reverse)
P1B Modulated
P1C Active
P1D Inactive
Relationships:
• Period = 4 * TOSC * (PR2 + 1) * (TMR2 Prescale Value)
• Pulse Width = TOSC * (CCPR1L:CCP1CON) * (TMR2 Prescale Value)
• Delay = 4 * TOSC * (PWM1CON)
Note 1: Dead-band delay is programmed using the PWM1CON register (Section 13.4.6 “Programmable Dead-Band Delay
Mode”).
2009-2016 Microchip Technology Inc.
DS40001365F-page 111
PIC18(L)F1XK22
FIGURE 13-5:
EXAMPLE ENHANCED PWM OUTPUT RELATIONSHIPS (ACTIVE-LOW STATE)
Signal
P1M
PR2+1
Pulse
Width
0
Period
00
(Single Output)
P1A Modulated
P1A Modulated
10
(Half-Bridge)
Delay(1)
Delay(1)
P1B Modulated
P1A Active
01
(Full-Bridge,
Forward)
P1B Inactive
P1C Inactive
P1D Modulated
P1A Inactive
11
(Full-Bridge,
Reverse)
P1B Modulated
P1C Active
P1D Inactive
Relationships:
• Period = 4 * TOSC * (PR2 + 1) * (TMR2 Prescale Value)
• Pulse Width = TOSC * (CCPR1L:CCP1CON) * (TMR2 Prescale Value)
• Delay = 4 * TOSC * (PWM1CON)
Note
1:
Dead-band delay is programmed using the PWM1CON register (Section 13.4.6 “Programmable Dead-Band Delay
Mode”).
DS40001365F-page 112
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
13.4.1
HALF-BRIDGE MODE
In Half-Bridge mode, two pins are used as outputs to
drive push-pull loads. The PWM output signal is output
on the CCP1/P1A pin, while the complementary PWM
output signal is output on the P1B pin (see
Figure 13-6). This mode can be used for half-bridge
applications, as shown in Figure 13-7, or for full-bridge
applications, where four power switches are being
modulated with two PWM signals.
In Half-Bridge mode, the programmable dead-band delay
can be used to prevent shoot-through current in
half-bridge power devices. The value of the PDC
bits of the PWM1CON register sets the number of
instruction cycles before the output is driven active. If the
value is greater than the duty cycle, the corresponding
output remains inactive during the entire cycle. See
Section 13.4.6 “Programmable Dead-Band Delay
Mode” for more details of the dead-band delay
operations.
Since the P1A and P1B outputs are multiplexed with
the PORT data latches, the associated TRIS bits must
be cleared to configure P1A and P1B as outputs.
FIGURE 13-6:
Period
Period
Pulse Width
P1A(2)
td
td
P1B(2)
(1)
(1)
(1)
td = Dead-Band Delay
Note 1:
2:
FIGURE 13-7:
EXAMPLE OF
HALF-BRIDGE PWM
OUTPUT
At this time, the TMR2 register is equal to the
PR2 register.
Output signals are shown as active-high.
EXAMPLE OF HALF-BRIDGE APPLICATIONS
Standard Half-Bridge Circuit (“Push-Pull”)
FET
Driver
+
P1A
Load
FET
Driver
+
P1B
-
Half-Bridge Output Driving a Full-Bridge Circuit
V+
FET
Driver
FET
Driver
P1A
FET
Driver
Load
FET
Driver
P1B
2009-2016 Microchip Technology Inc.
DS40001365F-page 113
PIC18(L)F1XK22
13.4.2
FULL-BRIDGE MODE
In Full-Bridge mode, all four pins are used as outputs.
An example of Full-Bridge application is shown in
Figure 13-8.
In the Forward mode, pin CCP1/P1A is driven to its
active state, pin P1D is modulated, while P1B and P1C
will be driven to their inactive state as shown in
Figure 13-9.
In the Reverse mode, P1C is driven to its active state,
pin P1B is modulated, while P1A and P1D will be driven
to their inactive state as shown Figure 13-9.
P1A, P1B, P1C and P1D outputs are multiplexed with
the PORT data latches. The associated TRIS bits must
be cleared to configure the P1A, P1B, P1C and P1D
pins as outputs.
FIGURE 13-8:
EXAMPLE OF FULL-BRIDGE APPLICATION
V+
FET
Driver
QC
QA
FET
Driver
P1A
Load
P1B
FET
Driver
P1C
FET
Driver
QD
QB
VP1D
DS40001365F-page 114
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 13-9:
EXAMPLE OF FULL-BRIDGE PWM OUTPUT
Forward Mode
Period
P1A
(2)
Pulse Width
P1B(2)
P1C(2)
P1D(2)
(1)
(1)
Reverse Mode
Period
Pulse Width
P1A(2)
P1B(2)
P1C(2)
P1D(2)
(1)
Note 1:
2:
(1)
At this time, the TMR2 register is equal to the PR2 register.
Output signal is shown as active-high.
2009-2016 Microchip Technology Inc.
DS40001365F-page 115
PIC18(L)F1XK22
13.4.2.1
Direction Change in Full-Bridge
Mode
In the Full-Bridge mode, the P1M1 bit in the CCP1CON
register allows users to control the forward/reverse
direction. When the application firmware changes this
direction control bit, the module will change to the new
direction on the next PWM cycle.
A direction change is initiated in software by changing
the P1M1 bit of the CCP1CON register. The following
sequence occurs prior to the end of the current PWM
period:
• The modulated outputs (P1B and P1D) are placed
in their inactive state.
• The associated unmodulated outputs (P1A and
P1C) are switched to drive in the opposite
direction.
• PWM modulation resumes at the beginning of the
next period.
See Figure 13-10 for an illustration of this sequence.
The Full-Bridge mode does not provide dead-band
delay. As one output is modulated at a time, dead-band
delay is generally not required. There is a situation
where dead-band delay is required. This situation
occurs when both of the following conditions are true:
1.
2.
The direction of the PWM output changes when
the duty cycle of the output is at or near 100%.
The turn off time of the power switch, including
the power device and driver circuit, is greater
than the turn on time.
Figure 13-11 shows an example of the PWM direction
changing from forward to reverse, at a near 100% duty
cycle. In this example, at time t1, the output P1A and
P1D become inactive, while output P1C becomes
active. Since the turn off time of the power devices is
longer than the turn on time, a shoot-through current
will flow through power devices QC and QD (see
Figure 13-8) for the duration of ‘t’. The same
phenomenon will occur to power devices QA and QB
for PWM direction change from reverse to forward.
If changing PWM direction at high duty cycle is required
for an application, two possible solutions for eliminating
the shoot-through current are:
1.
2.
Reduce PWM duty cycle for one PWM period
before changing directions.
Use switch drivers that can drive the switches off
faster than they can drive them on.
Other options to prevent shoot-through current may
exist.
FIGURE 13-10:
EXAMPLE OF PWM DIRECTION CHANGE
Period(1)
Signal
Period
P1A (Active-High)
P1B (Active-High)
Pulse Width
P1C (Active-High)
(2)
P1D (Active-High)
Pulse Width
Note 1:
2:
The direction bit P1M1 of the CCP1CON register is written any time during the PWM cycle.
When changing directions, the P1A and P1C signals switch before the end of the current PWM cycle. The
modulated P1B and P1D signals are inactive at this time. The length of this time is (1/FOSC) TMR2 prescale
value.
DS40001365F-page 116
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 13-11:
EXAMPLE OF PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE
Forward Period
t1
Reverse Period
P1A
P1B
PW
P1C
P1D
PW
TON
External Switch C
TOFF
External Switch D
Potential
Shoot-Through Current
Note 1:
13.4.3
All signals are shown as active-high.
2:
TON is the turn on delay of power switch QC and its driver.
3:
TOFF is the turn off delay of power switch QD and its driver.
START-UP CONSIDERATIONS
When any PWM mode is used, the application
hardware must use the proper external pull-up and/or
pull-down resistors on the PWM output pins.
Note:
T = TOFF – TON
When the microcontroller is released from
Reset, all of the I/O pins are in the
high-impedance state. The external
circuits must keep the power switch
devices in the Off state until the
microcontroller drives the I/O pins with the
proper signal levels or activates the PWM
output(s).
The P1A, P1B, P1C and P1D output latches may not be
in the proper states when the PWM module is
initialized. Enabling the PWM pin output drivers at the
same time as the Enhanced PWM modes may cause
damage to the application circuit. The Enhanced PWM
modes must be enabled in the proper Output mode and
complete a full PWM cycle before enabling the PWM
pin output drivers. The completion of a full PWM cycle
is indicated by the TMR2IF bit of the PIR1 register
being set as the second PWM period begins.
The CCP1M bits of the CCP1CON register allow
the user to choose whether the PWM output signals are
active-high or active-low for each pair of PWM output pins
(P1A/P1C and P1B/P1D). The PWM output polarities
must be selected before the PWM pin output drivers are
enabled. Changing the polarity configuration while the
PWM pin output drivers are enable is not recommended
since it may result in damage to the application circuits.
2009-2016 Microchip Technology Inc.
DS40001365F-page 117
PIC18(L)F1XK22
13.4.4
ENHANCED PWM
AUTO-SHUTDOWN MODE
When a shutdown event occurs, two things happen:
The PWM mode supports an Auto-Shutdown mode that
will disable the PWM outputs when an external
shutdown event occurs. Auto-Shutdown mode places
the PWM output pins into a predetermined state. This
mode is used to help prevent the PWM from damaging
the application.
The auto-shutdown sources are selected using the
ECCPAS bits of the ECCPAS register. A shutdown
event may be generated by:
• A logic ‘0’ on the INT0 pin
• A logic ‘1’ on a comparator (Cx) output
The ECCPASE bit is set to ‘1’. The ECCPASE will
remain set until cleared in firmware or an auto-restart
occurs (see Section 13.4.5 “Auto-Restart Mode”).
The enabled PWM pins are asynchronously placed in
their shutdown states. The PWM output pins are
grouped into pairs [P1A/P1C] and [P1B/P1D]. The state
of each pin pair is determined by the PSSAC and
PSSBD bits of the ECCPAS register. Each pin pair may
be placed into one of three states:
• Drive logic ‘1’
• Drive logic ‘0’
• Tri-state (high-impedance)
A shutdown condition is indicated by the ECCPASE
(Auto-Shutdown Event Status) bit of the ECCPAS
register. If the bit is a ‘0’, the PWM pins are operating
normally. If the bit is a ‘1’, the PWM outputs are in the
shutdown state.
REGISTER 13-2:
ECCP1AS: ENHANCED CAPTURE/COMPARE/PWM AUTO-SHUTDOWN
CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
ECCPASE
ECCPAS2
ECCPAS1
ECCPAS0
PSSAC1
PSSAC0
PSSBD1
PSSBD0
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
ECCPASE: ECCP Auto-Shutdown Event Status bit
1 = A shutdown event has occurred; ECCP outputs are in shutdown state
0 = ECCP outputs are operating
bit 6-4
ECCPAS: ECCP Auto-shutdown Source Select bits
000 = Auto-Shutdown is disabled
001 = Comparator C1OUT output is high
010 = Comparator C2OUT output is high
011 = Either Comparator C1OUT or C2OUT is high
100 = VIL on INT0 pin
101 = VIL on INT0 pin or Comparator C1OUT output is high
110 = VIL on INT0 pin or Comparator C2OUT output is high
111 = VIL on INT0 pin or Comparator C1OUT or Comparator C2OUT is high
bit 3-2
PSSACn: Pins P1A and P1C Shutdown State Control bits
00 = Drive pins P1A and P1C to ‘0’
01 = Drive pins P1A and P1C to ‘1’
10 = Pins 1A and P1C tri-state
11 = Reserved, do not use
bit 1-0
PSSBDn: Pins P1B and P1D Shutdown State Control bits
00 = Drive pins P1B and P1D to ‘0’
01 = Drive pins P1B and P1D to ‘1’
10 = Pins P1B and P1D tri-state
11 = Reserved, do not use
DS40001365F-page 118
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
Note 1: The auto-shutdown condition is a
level-based signal, not an edge-based
signal. As long as the level is present, the
auto-shutdown will persist.
2: Writing to the ECCPASE bit is disabled
while an auto-shutdown condition
persists.
3: Once the auto-shutdown condition has
been removed and the PWM restarted
(either through firmware or auto-restart)
the PWM signal will always restart at the
beginning of the next PWM period.
4: Prior to an auto-shutdown event caused
by a comparator output or INT pin event,
a software shutdown can be triggered in
firmware by setting the CCPxASE bit to a
‘1’. The Auto-Restart feature tracks the
active status of a shutdown caused by a
comparator output or INT pin event only,
so if it is enabled at this time, it will
immediately clear this bit and restart the
ECCP module at the beginning of the
next PWM period.
FIGURE 13-12:
PWM AUTO-SHUTDOWN WITH FIRMWARE RESTART (PRSEN = 0)
PWM Period
Shutdown Event
ECCPASE bit
PWM Activity
Normal PWM
Start of
PWM Period
2009-2016 Microchip Technology Inc.
ECCPASE
Cleared by
Shutdown
Shutdown Firmware PWM
Event Occurs Event Clears
Resumes
DS40001365F-page 119
PIC18(L)F1XK22
13.4.5
AUTO-RESTART MODE
The Enhanced PWM can be configured to
automatically restart the PWM signal once the
auto-shutdown condition has been removed.
Auto-restart is enabled by setting the PRSEN bit in the
PWM1CON register.
If auto-restart is enabled, the ECCPASE bit will remain
set as long as the auto-shutdown condition is active.
When the auto-shutdown condition is removed, the
ECCPASE bit will be cleared via hardware and normal
operation will resume.
FIGURE 13-13:
PWM AUTO-SHUTDOWN WITH AUTO-RESTART ENABLED (PRSEN = 1)
PWM Period
Shutdown Event
ECCPASE bit
PWM Activity
Normal PWM
Start of
PWM Period
DS40001365F-page 120
Shutdown
Shutdown
Event Occurs Event Clears
PWM
Resumes
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
13.4.6
PROGRAMMABLE DEAD-BAND
DELAY MODE
FIGURE 13-14:
In half-bridge applications where all power switches are
modulated at the PWM frequency, the power switches
normally require more time to turn off than to turn on. If
both the upper and lower power switches are switched
at the same time (one turned on, and the other turned
off), both switches may be on for a short period of time
until one switch completely turns off. During this brief
interval, a very high current (shoot-through current) will
flow through both power switches, shorting the bridge
supply. To avoid this potentially destructive
shoot-through current from flowing during switching,
turning on either of the power switches is normally
delayed to allow the other switch to completely turn off.
In Half-Bridge mode, a digitally programmable
dead-band delay is available to avoid shoot-through
current from destroying the bridge power switches. The
delay occurs at the signal transition from the non-active
state to the active state. See Figure 13-14 for
illustration. The lower seven bits of the associated
PWM1CON register (Register 13-3) sets the delay
period in terms of microcontroller instruction cycles
(TCY or 4 TOSC).
FIGURE 13-15:
EXAMPLE OF
HALF-BRIDGE PWM
OUTPUT
Period
Period
Pulse Width
P1A(2)
td
td
P1B(2)
(1)
(1)
(1)
td = Dead-Band Delay
Note 1:
2:
At this time, the TMR2 register is equal to the
PR2 register.
Output signals are shown as active-high.
EXAMPLE OF HALF-BRIDGE APPLICATIONS
V+
Standard Half-Bridge Circuit (“Push-Pull”)
FET
Driver
+
V
-
P1A
Load
FET
Driver
+
V
-
P1B
V-
2009-2016 Microchip Technology Inc.
DS40001365F-page 121
PIC18(L)F1XK22
REGISTER 13-3:
PWM1CON: ENHANCED PWM CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
PRSEN
PDC6
PDC5
PDC4
PDC3
PDC2
PDC1
PDC0
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
PRSEN: PWM Restart Enable bit
1 = Upon auto-shutdown, the ECCPASE bit clears automatically once the shutdown event goes
away; the PWM restarts automatically
0 = Upon auto-shutdown, ECCPASE must be cleared by software to restart the PWM
bit 6-0
PDC: PWM Delay Count bits
PDCn = Number of FOSC/4 (4 * TOSC) cycles between the scheduled time when a PWM signal
should transition active and the actual time it transitions active
DS40001365F-page 122
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
13.4.7
PULSE STEERING MODE
In Single Output mode, pulse steering allows any of the
PWM pins to be the modulated signal. Additionally, the
same PWM signal can be simultaneously available on
multiple pins.
Once the Single Output mode is selected
(CCP1M = 11 and P1M = 00 of the
CCP1CON register), the user firmware can bring out
the same PWM signal to one, two, three or four output
pins by setting the appropriate STR bits of the
PSTRCON register, as shown in Table 13-2.
REGISTER 13-4:
Note:
The associated TRIS bits must be set to
output (‘0’) to enable the pin output driver
in order to see the PWM signal on the pin.
While the PWM Steering mode is active, CCP1M
bits of the CCP1CON register select the PWM output
polarity for the P1 pins.
The PWM auto-shutdown operation also applies to
PWM Steering mode as described in Section 13.4.4
“Enhanced PWM Auto-shutdown mode”. An
auto-shutdown event will only affect pins that have
PWM outputs enabled.
PSTRCON: PULSE STEERING CONTROL REGISTER(1)
U-0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-1
—
—
—
STRSYNC
STRD
STRC
STRB
STRA
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
STRSYNC: Steering Sync bit
1 = Output steering update occurs on next PWM period
0 = Output steering update occurs at the beginning of the instruction cycle boundary
bit 3
STRD: Steering Enable bit D
1 = P1D pin has the PWM waveform with polarity control from CCP1M
0 = P1D pin is assigned to port pin
bit 2
STRC: Steering Enable bit C
1 = P1C pin has the PWM waveform with polarity control from CCP1M
0 = P1C pin is assigned to port pin
bit 1
STRB: Steering Enable bit B
1 = P1B pin has the PWM waveform with polarity control from CCP1M
0 = P1B pin is assigned to port pin
bit 0
STRA: Steering Enable bit A
1 = P1A pin has the PWM waveform with polarity control from CCP1M
0 = P1A pin is assigned to port pin
Note 1:
The PWM Steering mode is available only when the CCP1CON register bits CCP1M = 11 and
P1M = 00.
2009-2016 Microchip Technology Inc.
DS40001365F-page 123
PIC18(L)F1XK22
FIGURE 13-16:
SIMPLIFIED STEERING
BLOCK DIAGRAM
STRA
P1A Signal
CCP1M1
1
PORT Data
0
P1A pin
STRB
CCP1M0
1
PORT Data
0
STRC
CCP1M1
1
PORT Data
0
PORT Data
P1B pin
TRIS
P1C pin
TRIS
STRD
CCP1M0
TRIS
P1D pin
1
0
TRIS
Note 1:
Port outputs are configured as shown when
the CCP1CON register bits P1M = 00
and CCP1M = 11.
2:
Single PWM output requires setting at least
one of the STRx bits.
DS40001365F-page 124
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
13.4.7.1
Steering Synchronization
The STRSYNC bit of the PSTRCON register gives the
user two selections of when the steering event will
happen. When the STRSYNC bit is ‘0’, the steering
event will happen at the end of the instruction that
writes to the PSTRCON register. In this case, the
output signal at the P1 pins may be an
incomplete PWM waveform. This operation is useful
when the user firmware needs to immediately remove
a PWM signal from the pin.
FIGURE 13-17:
When the STRSYNC bit is ‘1’, the effective steering
update will happen at the beginning of the next PWM
period. In this case, steering on/off the PWM output will
always produce a complete PWM waveform.
Figures 13-17 and 13-18 illustrate the timing diagrams
of the PWM steering depending on the STRSYNC
setting.
EXAMPLE OF STEERING EVENT AT END OF INSTRUCTION (STRSYNC = 0)
PWM Period
PWM
STRn
P1
PORT Data
PORT Data
P1n = PWM
FIGURE 13-18:
EXAMPLE OF STEERING EVENT AT BEGINNING OF INSTRUCTION
(STRSYNC = 1)
PWM
STRn
P1
PORT Data
PORT Data
P1n = PWM
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PIC18(L)F1XK22
13.4.8
OPERATION IN POWER-MANAGED
MODES
13.4.8.1
Operation with Fail-Safe
Clock Monitor
In Sleep mode, all clock sources are disabled. Timer2
will not increment and the state of the module will not
change. If the ECCP pin is driving a value, it will
continue to drive that value. When the device wakes
up, it will continue from this state. If Two-Speed
Start-ups are enabled, the initial start-up frequency
from HFINTOSC and the postscaler may not be stable
immediately.
If the Fail-Safe Clock Monitor is enabled, a clock failure
will force the device into the RC_RUN Power-Managed
mode and the OSCFIF bit of the PIR2 register will be
set. The ECCP will then be clocked from the internal
oscillator clock source, which may have a different
clock frequency than the primary clock.
In PRI_IDLE mode, the primary clock will continue to
clock the ECCP module without change. In all other
power-managed modes, the selected power-managed
mode clock will clock Timer2. Other power-managed
mode clocks will most likely be different than the
primary clock frequency.
13.4.9
TABLE 13-3:
Name
See the previous section for additional details.
Both Power-on Reset and subsequent Resets will force
all ports to Input mode and the CCP registers to their
Reset states.
This forces the enhanced CCP module to reset to a
state compatible with the standard CCP module.
REGISTERS ASSOCIATED WITH ECCP1 MODULE AND TIMER1 TO TIMER3
Bit 7
Bit 6
Bit 5
Bit 4
CCPR1H
Capture/Compare/PWM Register 1, High Byte
CCPR1L
Capture/Compare/PWM Register 1, Low Byte
CCP1CON
EFFECTS OF A RESET
P1M1
P1M0
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
247
247
DC1B1
DC1B0
CCP1M3
CCP1M2
CCP1M1
CCP1M0
247
247
ECCP1AS
ECCPASE ECCPAS2
ECCPAS1
ECCPAS0
PSSAC1
PSSAC0
PSSBD1
PSSBD0
INTCON
GIE/GIEH PEIE/GIEL
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
EEIP
BCLIP
—
TMR3IP
—
248
IPR1
—
ADIP
IPR2
OSCFIP
C1IP
C2IP
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
PIE2
OSCFIE
C1IE
C2IE
EEIE
BCLIE
—
TMR3IE
—
248
PIR1
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
OSCFIF
C1IF
C2IF
EEIF
BCLIF
—
TMR3IF
—
248
PIR2
PR2
PWM1CON
RCON
Timer2 Period Register
246
PRSEN
PDC6
PDC5
PDC4
PDC3
PDC2
PDC1
PDC0
247
IPEN
SBOREN
—
RI
TO
PD
POR
BOR
246
TMR1H
Timer1 Register, High Byte
246
TMR1L
Timer1 Register, Low Byte
246
TMR2
Timer2 Register
246
TMR3H
Timer3 Register, High Byte
247
TMR3L
Timer3 Register, Low Byte
TRISC
TRISC7
T1CON
RD16
T2CON
—
T3CON
Legend:
RD16
247
TRISC6
TRISC5
TRISC4
TRISC3
TRISC2
TRISC1
TRISC0
248
T1RUN
T1CKPS1
T1CKPS0
T1OSCEN
T1SYNC
TMR1CS
TMR1ON
246
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0
246
—
T3CKPS1
T3CKPS0
T3CCP1
T3SYNC
TMR3CS
TMR3ON
247
— = unimplemented, read as ‘0’. Shaded cells are not used during ECCP operation.
DS40001365F-page 126
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
14.0
14.1
MASTER SYNCHRONOUS
SERIAL PORT (MSSP)
MODULE
Master SSP (MSSP) Module
Overview
The Master Synchronous Serial Port (MSSP) module is
a serial interface, useful for communicating with other
peripheral or microcontroller devices. These peripheral
devices may be serial EEPROMs, shift registers,
display drivers, A/D converters, etc. The MSSP module
can operate in one of two modes:
• Serial Peripheral Interface (SPI)
• Inter-Integrated Circuit (I2C)
- Full Master mode
- Slave mode (with general address call)
14.2
SPI Mode
The SPI mode allows eight bits of data to be
synchronously
transmitted
and
received
simultaneously. All four modes of SPI are supported. To
accomplish communication, typically three pins are
used:
• Serial Data Out – SDO
• Serial Data In – SDI
• Serial Clock – SCK
Additionally, a fourth pin may be used when in a Slave
mode of operation:
• Slave Select – SS
Figure 14-1 shows the block diagram of the MSSP
module when operating in SPI mode.
FIGURE 14-1:
I2 C
The
interface supports the following modes in
hardware:
MSSP BLOCK DIAGRAM
(SPI MODE)
Internal
Data Bus
• Master mode
• Multi-Master mode
• Slave mode
Read
Write
SSPBUF Reg
SDI/SDA
SSPSR Reg
Shift
Clock
SDO
bit 0
SS
SS Control
Enable
Edge
Select
2
Clock Select
SSPM
4
SCK/SCL
Edge
Select
(TMR22Output)
Prescaler TOSC
4, 16, 64
TRIS bit
2009-2016 Microchip Technology Inc.
DS40001365F-page 127
PIC18(L)F1XK22
14.2.1
REGISTERS
SSPSR is the shift register used for shifting data in and
out. SSPBUF provides indirect access to the SSPSR
register. SSPBUF is the buffer register to which data
bytes are written, and from which data bytes are read.
The MSSP module has four registers for SPI mode
operation. These are:
•
•
•
•
SSPCON1 – Control Register
SSPSTAT – STATUS register
SSPBUF – Serial Receive/Transmit Buffer
SSPSR – Shift Register (Not directly accessible)
In receive operations, SSPSR and SSPBUF together
create a double-buffered receiver. When SSPSR
receives a complete byte, it is transferred to SSPBUF
and the SSPIF interrupt is set.
SSPCON1 and SSPSTAT are the control and STATUS
registers in SPI mode operation. The SSPCON1
register is readable and writable. The lower six bits of
the SSPSTAT are read-only. The upper two bits of the
SSPSTAT are read/write.
REGISTER 14-1:
During
transmission,
the
SSPBUF
is
not
double-buffered. A write to SSPBUF will write to both
SSPBUF and SSPSR.
SSPSTAT: MSSP STATUS REGISTER (SPI MODE)
R/W-0
R/W-0
R-0
R-0
R-0
R-0
R-0
R-0
SMP
CKE
D/A
P
S
R/W
UA
BF
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
SMP: Sample bit
SPI Master mode:
1 = Input data sampled at end of data output time
0 = Input data sampled at middle of data output time
SPI Slave mode:
SMP must be cleared when SPI is used in Slave mode.
bit 6
CKE: SPI Clock Select bit(1)
1 = Transmit occurs on transition from active to Idle clock state
0 = Transmit occurs on transition from Idle to active clock state
bit 5
D/A: Data/Address bit
Used in I2C mode only.
bit 4
P: Stop bit
Used in I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is cleared.
bit 3
S: Start bit
Used in I2C mode only.
bit 2
R/W: Read/Write Information bit
Used in I2C mode only.
bit 1
UA: Update Address bit
Used in I2C mode only.
bit 0
BF: Buffer Full Status bit (Receive mode only)
1 = Receive complete, SSPBUF is full
0 = Receive not complete, SSPBUF is empty
Note 1:
Polarity of clock state is set by the CKP bit of the SSPCON1 register.
DS40001365F-page 128
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 14-2:
SSPCON1: MSSP CONTROL 1 REGISTER (SPI MODE)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
WCOL: Write Collision Detect bit (Transmit mode only)
1 = The SSPBUF register is written while it is still transmitting the previous word
(must be cleared by software)
0 = No collision
bit 6
SSPOV: Receive Overflow Indicator bit(1)
SPI Slave mode:
1 = A new byte is received while the SSPBUF register is still holding the previous data. In case of
overflow, the data in SSPSR is lost. Overflow can only occur in Slave mode. The user must read
the SSPBUF, even if only transmitting data, to avoid setting overflow (must be cleared by
software).
0 = No overflow
bit 5
SSPEN: Synchronous Serial Port Enable bit(2)
1 = Enables serial port and configures SCK, SDO, SDI and SS as serial port pins
0 = Disables serial port and configures these pins as I/O port pins
bit 4
CKP: Clock Polarity Select bit
1 = Idle state for clock is a high level
0 = Idle state for clock is a low level
bit 3-0
SSPM: Synchronous Serial Port Mode Select bits(3)
0101 = SPI Slave mode, clock = SCK pin, SS pin control disabled, SS can be used as I/O pin
0100 = SPI Slave mode, clock = SCK pin, SS pin control enabled
0011 = SPI Master mode, clock = TMR2 output/2
0010 = SPI Master mode, clock = FOSC/64
0001 = SPI Master mode, clock = FOSC/16
0000 = SPI Master mode, clock = FOSC/4
Note 1:
2:
3:
In Master mode, the overflow bit is not set since each new reception (and transmission) is initiated by
writing to the SSPBUF register.
When enabled, these pins must be properly configured as input or output.
Bit combinations not specifically listed here are either reserved or implemented in I2C mode only.
2009-2016 Microchip Technology Inc.
DS40001365F-page 129
PIC18(L)F1XK22
14.2.2
OPERATION
When initializing the SPI, several options need to be
specified. This is done by programming the appropriate
control bits (SSPCON1 and SSPSTAT).
These control bits allow the following to be specified:
•
•
•
•
Master mode (SCK is the clock output)
Slave mode (SCK is the clock input)
Clock Polarity (Idle state of SCK)
Data Input Sample Phase (middle or end of data
output time)
• Clock Edge (output data on rising/falling edge of
SCK)
• Clock Rate (Master mode only)
• Slave Select mode (Slave mode only)
The MSSP consists of a transmit/receive shift register
(SSPSR) and a buffer register (SSPBUF). The SSPSR
shifts the data in and out of the device, MSb first. The
SSPBUF holds the data that was written to the SSPSR
until the received data is ready. Once the 8 bits of data
have been received, that byte is moved to the SSPBUF
register. Then, the Buffer Full detect bit, BF of the
SSPSTAT register, and the interrupt flag bit, SSPIF, are
set. This double-buffering of the received data
(SSPBUF) allows the next byte to start reception before
reading the data that was just received. Any write to the
SSPBUF register during transmission/reception of data
will be ignored and the write collision detect bit WCOL
of the SSPCON1 register, will be set. User software
must clear the WCOL bit to allow the following write(s)
to the SSPBUF register to complete successfully.
EXAMPLE 14-1:
LOOP
When the application software is expecting to receive
valid data, the SSPBUF should be read before the next
byte of data to transfer is written to the SSPBUF. The
Buffer Full bit, BF of the SSPSTAT register, indicates
when SSPBUF has been loaded with the received data
(transmission is complete). When the SSPBUF is read,
the BF bit is cleared. This data may be irrelevant if the
SPI is only a transmitter. Generally, the MSSP interrupt
is used to determine when the transmission/reception
has completed. If the interrupt method is not going to
be used, then software polling can be done to ensure
that a write collision does not occur. Example 14-1
shows the loading of the SSPBUF (SSPSR) for data
transmission.
The SSPSR is not directly readable or writable and can
only be accessed by addressing the SSPBUF register.
Additionally, the MSSP STATUS register (SSPSTAT)
indicates the various status conditions.
LOADING THE SSPBUF (SSPSR) REGISTER
BTFSS
BRA
MOVF
SSPSTAT, BF
LOOP
SSPBUF, W
;Has data been received (transmit complete)?
;No
;WREG reg = contents of SSPBUF
MOVWF
RXDATA
;Save in user RAM, if data is meaningful
MOVF
MOVWF
TXDATA, W
SSPBUF
;W reg = contents of TXDATA
;New data to xmit
DS40001365F-page 130
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
14.2.3
ENABLING SPI I/O
14.2.4
To enable the serial port, SSP Enable bit, SSPEN of the
SSPCON1 register, must be set. To reset or
reconfigure SPI mode, clear the SSPEN bit, reinitialize
the SSPCON registers and then set the SSPEN bit.
This configures the SDI, SDO, SCK and SS pins as
serial port pins. For the pins to behave as the serial port
function, some must have their data direction bits (in
the TRIS register) appropriately programmed as
follows:
• SDI is automatically controlled by the SPI module
• SDO must have corresponding TRIS bit cleared
• SCK (Master mode) must have corresponding
TRIS bit cleared
• SCK (Slave mode) must have corresponding
TRIS bit set
• SS must have corresponding TRIS bit set
TYPICAL CONNECTION
Figure 14-2 shows a typical connection between two
microcontrollers. The master controller (Processor 1)
initiates the data transfer by sending the SCK signal.
Data is shifted out of both shift registers on their
programmed clock edge and latched on the opposite
edge of the clock. Both processors should be
programmed to the same Clock Polarity (CKP), then
both controllers would send and receive data at the
same time. Whether the data is meaningful (or dummy
data) depends on the application software. This leads
to three scenarios for data transmission:
• Master sends data–Slave sends dummy data
• Master sends data–Slave sends data
• Master sends dummy data–Slave sends data
Any serial port function that is not desired may be
overridden by programming the corresponding data
direction (TRIS) register to the opposite value.
FIGURE 14-2:
TYPICAL SPI MASTER/SLAVE CONNECTION
SPI Slave SSPM = 010x
SPI Master SSPM = 00xx
SDO
SDI
Serial Input Buffer
(SSPBUF)
SDI
Shift Register
(SSPSR)
MSb
Serial Input Buffer
(SSPBUF)
LSb
SCK
General I/O
Processor 1
2009-2016 Microchip Technology Inc.
SDO
Serial Clock
Slave Select
(optional)
Shift Register
(SSPSR)
MSb
LSb
SCK
SS
Processor 2
DS40001365F-page 131
PIC18(L)F1XK22
14.2.5
MASTER MODE
The master can initiate the data transfer at any time
because it controls the SCK. The master determines
when the slave (Processor 2, Figure 14-2) is to
broadcast data by the software protocol.
In Master mode, the data is transmitted/received as
soon as the SSPBUF register is written to. If the SPI is
only going to receive, the SDO output could be
disabled (programmed as an input). The SSPSR
register will continue to shift in the signal present on the
SDI pin at the programmed clock rate. As each byte is
received, it will be loaded into the SSPBUF register as
if a normal received byte (interrupts and Status bits
appropriately set).
FIGURE 14-3:
The clock polarity is selected by appropriately
programming the CKP bit of the SSPCON1 register.
This then, would give waveforms for SPI
communication as shown in Figure 14-3, Figure 14-5
and Figure 14-6, where the MSB is transmitted first. In
Master mode, the SPI clock rate (bit rate) is user
programmable to be one of the following:
•
•
•
•
FOSC/4 (or TCY)
FOSC/16 (or 4 • TCY)
FOSC/64 (or 16 • TCY)
Timer2 output/2
This allows a maximum data rate (at 64 MHz) of
16.00 Mbps.
Figure 14-3 shows the waveforms for Master mode.
When the CKE bit is set, the SDO data is valid before
there is a clock edge on SCK. The change of the input
sample is shown based on the state of the SMP bit. The
time when the SSPBUF is loaded with the received
data is shown.
SPI MODE WAVEFORM (MASTER MODE)
Write to
SSPBUF
SCK
(CKP = 0
CKE = 0)
SCK
(CKP = 1
CKE = 0)
4 Clock
Modes
SCK
(CKP = 0
CKE = 1)
SCK
(CKP = 1
CKE = 1)
SDO
(CKE = 0)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
SDO
(CKE = 1)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
SDI
(SMP = 0)
bit 0
bit 7
Input
Sample
(SMP = 0)
SDI
(SMP = 1)
bit 7
bit 0
Input
Sample
(SMP = 1)
SSPIF
SSPSR to
SSPBUF
DS40001365F-page 132
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
14.2.6
SLAVE MODE
14.2.7
In Slave mode, the data is transmitted and received as
external clock pulses appear on SCK. When the last bit
is latched, the SSPIF interrupt flag bit is set.
Before enabling the module in SPI Slave mode, the clock
line must match the proper Idle state. The clock line can
be observed by reading the SCK pin. The Idle state is
determined by the CKP bit of the SSPCON1 register.
While in Slave mode, the external clock is supplied by
the external clock source on the SCK pin. This external
clock must meet the minimum high and low times as
specified in the electrical specifications.
While in Sleep mode, the slave can transmit/receive
data. When a byte is received, the device will wake-up
from Sleep.
SLAVE SELECT
SYNCHRONIZATION
The SS pin allows a Synchronous Slave mode. The
SPI must be in Slave mode with SS pin control enabled
(SSPCON1 = 0100). When the SS pin is low,
transmission and reception are enabled and the SDO
pin is driven. When the SS pin goes high, the SDO pin
is no longer driven, even if in the middle of a transmitted
byte and becomes a floating output. External
pull-up/pull-down resistors may be desirable
depending on the application.
Note 1: When the SPI is in Slave mode with SS pin
control enabled (SSPCON = 0100),
the SPI module will reset if the SS pin is
set to VDD.
2: When the SPI is used in Slave mode with
CKE set the SS pin control must also be
enabled.
When the SPI module resets, the bit counter is forced
to ‘0’. This can be done by either forcing the SS pin to
a high level or clearing the SSPEN bit.
FIGURE 14-4:
SLAVE SYNCHRONIZATION WAVEFORM
SS
SCK
(CKP = 0
CKE = 0)
SCK
(CKP = 1
CKE = 0)
Write to
SSPBUF
SDO
SDI
(SMP = 0)
bit 7
bit 6
bit 7
bit 0
bit 0
bit 7
bit 7
Input
Sample
(SMP = 0)
SSPIF
Interrupt
Flag
SSPSR to
SSPBUF
2009-2016 Microchip Technology Inc.
DS40001365F-page 133
PIC18(L)F1XK22
FIGURE 14-5:
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)
SS
Optional
SCK
(CKP = 0
CKE = 0)
SCK
(CKP = 1
CKE = 0)
Write to
SSPBUF
SDO
SDI
(SMP = 0)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
bit 0
bit 7
Input
Sample
(SMP = 0)
SSPIF
Interrupt
Flag
SSPSR to
SSPBUF
FIGURE 14-6:
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)
SS
Not Optional
SCK
(CKP = 0
CKE = 1)
SCK
(CKP = 1
CKE = 1)
Write to
SSPBUF
SDO
bit 7
SDI
(SMP = 0)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
bit 0
Input
Sample
(SMP = 0)
SSPIF
Interrupt
Flag
SSPSR to
SSPBUF
DS40001365F-page 134
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
14.2.8
OPERATION IN POWER-MANAGED
MODES
Transmit/Receive Shift register. When all eight bits
have been received, the MSSP interrupt flag bit will be
set and if enabled, will wake the device.
In SPI Master mode, module clocks may be operating
at a different speed than when in Full Power mode; in
the case of the Sleep mode, all clocks are halted.
14.2.9
In all Idle modes, a clock is provided to the peripherals.
That clock could be from the primary clock source, the
secondary clock (Timer1 oscillator at 32.768 kHz) or
the INTOSC source. See Section 18.0 “Power-Managed Modes” for additional information.
14.2.10
In most cases, the speed that the master clocks SPI
data is not important; however, this should be
evaluated for each system.
EFFECTS OF A RESET
A Reset disables the MSSP module and terminates the
current transfer.
BUS MODE COMPATIBILITY
Table 14-1 shows the compatibility between the
standard SPI modes and the states of the CKP and
CKE control bits.
TABLE 14-1:
When MSSP interrupts are enabled, after the master
completes sending data, an MSSP interrupt will wake
the controller:
SPI BUS MODES
Control Bits State
Standard SPI Mode
Terminology
CKP
CKE
• From Sleep, in Slave mode
• From Idle, in Slave or Master mode
0, 0
0
1
0, 1
0
0
If an exit from Sleep or Idle mode is not desired, MSSP
interrupts should be disabled.
1, 0
1
1
1, 1
1
0
In SPI Master mode, when the Sleep mode is selected,
all
module
clocks
are
halted
and
the
transmission/reception will remain in that state until the
device wakes. After the device returns to Run mode,
the module will resume transmitting and receiving data.
There is also an SMP bit which controls when the data
is sampled.
In SPI Slave mode, the SPI Transmit/Receive Shift
register operates asynchronously to the device. This
allows the device to be placed in any Power-Managed
mode and data to be shifted into the SPI
TABLE 14-2:
REGISTERS ASSOCIATED WITH SPI OPERATION
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
PIR1
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
TRISB
TRISB7
TRISB6
TRISB5
TRISB4
—
—
—
—
248
TRISC
TRISC7
TRISC6
TRISC5
TRISC4
TRISC3
TRISC2
TRISC1
TRISC0
248
Name
INTCON
SSPBUF
Bit 7
Bit 6
Bit 5
SSP Receive Buffer/Transmit Register
246
SSPCON1
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
246
SSPSTAT
SMP
CKE
D/A
P
S
R/W
UA
BF
246
Legend: Shaded cells are not used by the MSSP in SPI mode.
2009-2016 Microchip Technology Inc.
DS40001365F-page 135
PIC18(L)F1XK22
14.3
I2C Mode
14.3.1
The MSSP module in I 2C mode fully implements all
master and slave functions (including general call
support) and provides interrupts on Start and Stop bits
in hardware to determine a free bus (multi-master
function). The MSSP module implements the standard
mode specifications as well as 7-bit and 10-bit
addressing.
Two pins are used for data transfer:
• Serial clock – SCL
• Serial data – SDA
Note:
The user must configure these pins as
inputs with the corresponding TRIS bits.
FIGURE 14-7:
MSSP BLOCK DIAGRAM
(I2C MODE)
Internal
Data Bus
Read
Write
SSPBUF Reg
SCK/SCL
SSPSR Reg
LSb
MSb
SSPMSK Reg
Match Detect
Addr Match
SSPADD Reg
Start and
Stop bit Detect
DS40001365F-page 136
The MSSP module has seven registers for I2C
operation. These are:
•
•
•
•
MSSP Control Register 1 (SSPCON1)
MSSP Control Register 2 (SSPCON2)
MSSP Status register (SSPSTAT)
Serial Receive/Transmit Buffer Register
(SSPBUF)
• MSSP Shift Register (SSPSR) – Not directly
accessible
• MSSP Address Register (SSPADD)
• MSSP Address Mask (SSPMSK)
SSPCON1, SSPCON2 and SSPSTAT are the control
and STATUS registers in I2C mode operation. The
SSPCON1 and SSPCON2 registers are readable and
writable. The lower six bits of the SSPSTAT are
read-only. The upper two bits of the SSPSTAT are
read/write.
SSPSR is the shift register used for shifting data in or
out. SSPBUF is the buffer register to which data bytes
are written to or read from.
When the MSSP is configured in Master mode, the
SSPADD register acts as the Baud Rate Generator
reload value. When the MSSP is configured for I2C
Slave mode the SSPADD register holds the slave
device address. The MSSP can be configured to
respond to a range of addresses by qualifying selected
bits of the address register with the SSPMSK register.
Shift
Clock
SDI/SDA
REGISTERS
Set, Reset
S, P bits
(SSPSTAT Reg)
In receive operations, SSPSR and SSPBUF together
create a double-buffered receiver. When SSPSR
receives a complete byte, it is transferred to SSPBUF
and the SSPIF interrupt is set.
During
transmission,
the
SSPBUF
is
not
double-buffered. A write to SSPBUF will write to both
SSPBUF and SSPSR.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 14-3:
R/W-0
SSPSTAT: MSSP STATUS REGISTER (I2C MODE)
R/W-0
SMP
CKE
R-0
R-0
R-0
D/A
(1)
(1)
P
S
R-0
R/W
(2, 3)
R-0
R-0
UA
BF
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
SMP: Slew Rate Control bit
In Master or Slave mode:
1 = Slew rate control disabled for standard Speed mode (100 kHz and 1 MHz)
0 = Slew rate control enabled for High-Speed mode (400 kHz)
bit 6
CKE: SMBus Select bit
In Master or Slave mode:
1 = Enable SMBus specific inputs
0 = Disable SMBus specific inputs
bit 5
D/A: Data/Address bit
In Master mode:
Reserved.
In Slave mode:
1 = Indicates that the last byte received or transmitted was data
0 = Indicates that the last byte received was an address
bit 4
P: Stop bit(1)
1 = Indicates that a Stop bit has been detected last
0 = Stop bit was not detected last
bit 3
S: Start bit(1)
1 = Indicates that a Start bit has been detected last
0 = Start bit was not detected last
bit 2
R/W: Read/Write Information bit (I2C mode only)(2, 3)
In Slave mode:
1 = Read
0 = Write
In Master mode:
1 = Transmit is in progress
0 = Transmit is not in progress
bit 1
UA: Update Address bit (10-bit Slave mode only)
1 = Indicates that the user needs to update the address in the SSPADD register
0 = Address does not need to be updated
bit 0
BF: Buffer Full Status bit
In Transmit mode:
1 = SSPBUF is full
0 = SSPBUF is empty
In Receive mode:
1 = SSPBUF is full (does not include the ACK and Stop bits)
0 = SSPBUF is empty (does not include the ACK and Stop bits)
Note 1:
2:
3:
This bit is cleared on Reset and when SSPEN is cleared.
This bit holds the R/W bit information following the last address match. This bit is only valid from the
address match to the next Start bit, Stop bit or not ACK bit.
ORing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the Master mode is active.
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DS40001365F-page 137
PIC18(L)F1XK22
SSPCON1: MSSP CONTROL 1 REGISTER (I2C MODE)
REGISTER 14-4:
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
WCOL: Write Collision Detect bit
In Master Transmit mode:
1 = A write to the SSPBUF register was attempted while the I2C conditions were not valid for a
transmission to be started (must be cleared by software)
0 = No collision
In Slave Transmit mode:
1 = The SSPBUF register is written while it is still transmitting the previous word (must be cleared by
software)
0 = No collision
In Receive mode (Master or Slave modes):
This is a “don’t care” bit.
bit 6
SSPOV: Receive Overflow Indicator bit
In Receive mode:
1 = A byte is received while the SSPBUF register is still holding the previous byte (must be cleared
by software)
0 = No overflow
In Transmit mode:
This is a “don’t care” bit in Transmit mode.
bit 5
SSPEN: Synchronous Serial Port Enable bit
1 = Enables the serial port and configures the SDA and SCL pins as the serial port pins
0 = Disables serial port and configures these pins as I/O port pins
When enabled, the SDA and SCL pins must be properly configured as inputs.
bit 4
CKP: SCK Release Control bit
In Slave mode:
1 = Release clock
0 = Holds clock low (clock stretch), used to ensure data setup time
In Master mode:
Unused in this mode.
bit 3-0
SSPM: Synchronous Serial Port Mode Select bits
1111 = I2C Slave mode, 10-bit address with Start and Stop bit interrupts enabled
1110 = I2C Slave mode, 7-bit address with Start and Stop bit interrupts enabled
1011 = I2C Firmware Controlled Master mode (Slave Idle)
1000 = I2C Master mode, clock = FOSC/(4 * (SSPADD + 1))
0111 = I2C Slave mode, 10-bit address
0110 = I2C Slave mode, 7-bit address
Bit combinations not specifically listed here are either reserved or implemented in SPI mode only.
DS40001365F-page 138
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 14-5:
R/W-0
GCEN
SSPCON2: MSSP CONTROL REGISTER (I2C MODE)
R/W-0
R/W-0
ACKSTAT
ACKDT(2)
R/W-0
(1)
ACKEN
R/W-0
(1)
RCEN
R/W-0
(1)
PEN
R/W-0
(1)
RSEN
R/W-0
SEN(1)
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
GCEN: General Call Enable bit (Slave mode only)
1 = Generate interrupt when a general call address 0x00 or 00h is received in the SSPSR
0 = General call address disabled
bit 6
ACKSTAT: Acknowledge Status bit (Master Transmit mode only)
1 = Acknowledge was not received from slave
0 = Acknowledge was received from slave
bit 5
ACKDT: Acknowledge Data bit (Master Receive mode only)(2)
1 = Not Acknowledge
0 = Acknowledge
bit 4
ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only)(1)
1 = Initiate Acknowledge sequence on SDA and SCL pins and transmit ACKDT data bit.
Automatically cleared by hardware.
0 = Acknowledge sequence Idle
bit 3
RCEN: Receive Enable bit (Master mode only)(1)
1 = Enables Receive mode for I2C
0 = Receive Idle
bit 2
PEN: Stop Condition Enable bit (Master mode only)(1)
1 = Initiate Stop condition on SDA and SCL pins. Automatically cleared by hardware.
0 = Stop condition Idle
bit 1
RSEN: Repeated Start Condition Enable bit (Master mode only)(1)
1 = Initiate Repeated Start condition on SDA and SCL pins. Automatically cleared by hardware.
0 = Repeated Start condition Idle
bit 0
SEN: Start Condition Enable/Stretch Enable bit(1)
In Master mode:
1 = Initiate Start condition on SDA and SCL pins. Automatically cleared by hardware.
0 = Start condition Idle
In Slave mode:
1 = Clock stretching is enabled for both slave transmit and slave receive (stretch enabled)
0 = Clock stretching is disabled
Note 1:
2:
For bits ACKEN, RCEN, PEN, RSEN, SEN: If the I2C module is not in the Idle mode, these bits may not
be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled).
Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive.
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DS40001365F-page 139
PIC18(L)F1XK22
14.3.2
OPERATION
The MSSP module functions are enabled by setting
SSPEN bit of the SSPCON1 register.
The SSPCON1 register allows control of the I 2C
operation. Four mode selection bits of the SSPCON1
register allow one of the following I 2C modes to be
selected:
I2C Master mode, clock = (FOSC/(4*(SSPADD + 1))
I 2C Slave mode (7-bit address)
I 2C Slave mode (10-bit address)
I 2C Slave mode (7-bit address) with Start and
Stop bit interrupts enabled
• I 2C Slave mode (10-bit address) with Start and
Stop bit interrupts enabled
• I 2C Firmware Controlled Master mode, slave is
Idle
•
•
•
•
Selection of any I 2C mode with the SSPEN bit set,
forces the SCL and SDA pins to be open-drain,
provided these pins are programmed to inputs by
setting the appropriate TRIS bits
Note:
14.3.3
To ensure proper operation of the module,
pull-up resistors must be provided
externally to the SCL and SDA pins.
SLAVE MODE
In Slave mode, the SCL and SDA pins must be
configured as inputs. The MSSP module will override
the input state with the output data when required
(slave-transmitter).
The I 2C Slave mode hardware will always generate an
interrupt on an address match. Through the mode
select bits, the user can also choose to interrupt on
Start and Stop bits
When an address is matched, or the data transfer after
an address match is received, the hardware
automatically will generate the Acknowledge (ACK)
pulse and load the SSPBUF register with the received
value currently in the SSPSR register.
Any combination of the following conditions will cause
the MSSP module not to give this ACK pulse:
• The Buffer Full bit, BF bit of the SSPSTAT
register, is set before the transfer is received.
• The overflow bit, SSPOV bit of the SSPCON1
register, is set before the transfer is received.
In this case, the SSPSR register value is not loaded
into the SSPBUF, but bit SSPIF of the PIR1 register is
set. The BF bit is cleared by reading the SSPBUF
register, while bit SSPOV is cleared through software.
The SCL clock input must have a minimum high and
low for proper operation. The high and low times of the
I2C specification, as well as the requirement of the
MSSP module, are shown in Section 26.0 “Electrical
Specifications”.
DS40001365F-page 140
14.3.3.1
Addressing
Once the MSSP module has been enabled, it waits for
a Start condition to occur. Following the Start condition,
the eight bits are shifted into the SSPSR register. All
incoming bits are sampled with the rising edge of the
clock (SCL) line. The value of register SSPSR is
compared to the value of the SSPADD register. The
address is compared on the falling edge of the eighth
clock (SCL) pulse. If the addresses match and the BF
and SSPOV bits are clear, the following events occur:
1.
2.
3.
4.
The SSPSR register value is loaded into the
SSPBUF register.
The Buffer Full bit, BF, is set.
An ACK pulse is generated.
MSSP Interrupt Flag bit, SSPIF of the PIR1
register, is set (interrupt is generated, if enabled)
on the falling edge of the ninth SCL pulse.
In 10-bit Address mode, two address bytes need to be
received by the slave. The five Most Significant bits
(MSbs) of the first address byte specify if this is a 10-bit
address. Bit R/W of the SSPSTAT register must specify
a write so the slave device will receive the second
address byte. For a 10-bit address, the first byte would
equal ‘11110 A9 A8 0’, where ‘A9’ and ‘A8’ are the two
MSbs of the address. The sequence of events for 10-bit
address is as follows, with steps 7 through 9 for the
slave-transmitter:
1.
Receive first (high) byte of address (bits SSPIF,
BF and UA of the SSPSTAT register are set).
2. Read the SSPBUF register (clears bit BF) and
clear flag bit, SSPIF.
3. Update the SSPADD register with second (low)
byte of address (clears bit UA and releases the
SCL line).
4. Receive second (low) byte of address (bits
SSPIF, BF and UA are set). If the address
matches then the SCL is held until the next step.
Otherwise the SCL line is not held.
5. Read the SSPBUF register (clears bit BF) and
clear flag bit, SSPIF.
6. Update the SSPADD register with the first (high)
byte of address. (This will clear bit UA and
release a held SCL line.)
7. Receive Repeated Start condition.
8. Receive first (high) byte of address with R/W bit
set (bits SSPIF, BF, R/W are set).
9. Read the SSPBUF register (clears bit BF) and
clear flag bit, SSPIF.
10. Load SSPBUF with byte the slave is to transmit,
sets the BF bit.
11. Set the CKP bit to release SCL.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
14.3.3.2
Reception
When the R/W bit of the address byte is clear and an
address match occurs, the R/W bit of the SSPSTAT
register is cleared. The received address is loaded into
the SSPBUF register and the SDA line is held low
(ACK).
When the address byte overflow condition exists, then
the no Acknowledge (ACK) pulse is given. An overflow
condition is defined as either bit BF bit of the SSPSTAT
register is set, or bit SSPOV bit of the SSPCON1
register is set.
An MSSP interrupt is generated for each data transfer
byte. Flag bit, SSPIF of the PIR1 register, must be
cleared by software.
When the SEN bit of the SSPCON2 register is set, SCL
will be held low (clock stretch) following each data
transfer. The clock must be released by setting the
CKP bit of the SSPCON1 register. See Section 14.3.4
“Clock Stretching” for more detail.
14.3.3.3
Transmission
When the R/W bit of the incoming address byte is set
and an address match occurs, the R/W bit of the
SSPSTAT register is set. The received address is
loaded into the SSPBUF register. The ACK pulse will
be sent on the ninth bit and pin SCK/SCL is held low
regardless of SEN (see Section 14.3.4 “Clock
Stretching” for more detail). By stretching the clock,
the master will be unable to assert another clock pulse
until the slave is done preparing the transmit data. The
transmit data must be loaded into the SSPBUF register
which also loads the SSPSR register. Then pin
SCK/SCL should be released by setting the CKP bit of
the SSPCON1 register. The eight data bits are shifted
out on the falling edge of the SCL input. This ensures
that the SDA signal is valid during the SCL high time
(Figure 14-9).
The ACK pulse from the master-receiver is latched on
the rising edge of the ninth SCL input pulse. If the SDA
line is high (not ACK), then the data transfer is complete.
In this case, when the ACK is latched by the slave, the
slave logic is reset (resets SSPSTAT register) and the
slave monitors for another occurrence of the Start bit. If
the SDA line was low (ACK), the next transmit data must
be loaded into the SSPBUF register. Again, pin
SCK/SCL must be released by setting bit CKP.
An MSSP interrupt is generated for each data transfer
byte. The SSPIF bit must be cleared by software and
the SSPSTAT register is used to determine the status
of the byte. The SSPIF bit is set on the falling edge of
the ninth clock pulse.
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DS40001365F-page 141
DS40001365F-page 142
CKP
2
A6
3
A5
4
A4
5
A3
6
A2
(CKP does not reset to ‘0’ when SEN = 0)
SSPOV (SSPCON1)
BF (SSPSTAT)
(PIR1)
SSPIF
1
SCL
S
A7
7
A1
8
9
ACK
R/W = 0
1
D7
3
4
D4
5
D3
Receiving Data
D5
Cleared by software
SSPBUF is read
2
D6
6
D2
7
D1
8
D0
9
ACK
1
D7
2
D6
3
4
D4
5
D3
Receiving Data
D5
6
D2
7
D1
8
D0
Bus master
terminates
transfer
P
SSPOV is set
because SSPBUF is
still full. ACK is not sent.
9
ACK
FIGURE 14-8:
SDA
Receiving Address
PIC18(L)F1XK22
I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS)
2009-2016 Microchip Technology Inc.
2009-2016 Microchip Technology Inc.
CKP
2
A6
Data in
sampled
1
BF (SSPSTAT)
SSPIF (PIR1)
S
A7
3
4
A4
5
A3
6
A2
Receiving Address
A5
8
R/W = 0
9
ACK
1
D7
SCL held low
while CPU
responds to SSPIF
SSPBUF is read by software
7
A1
3
D5
4
5
D3
CKP is set by software
SSPBUF is written by software
6
D2
Transmitting Data
D4
Cleared by software
2
D6
7
8
D0
9
ACK
From SSPIF ISR
D1
1
D7
4
D4
5
D3
6
D2
CKP is set by software
7
8
D0
9
ACK
From SSPIF ISR
D1
Transmitting Data
Cleared by software
3
D5
SSPBUF is written by software
2
D6
Bus master
terminates software
P
FIGURE 14-9:
SCL
SDA
PIC18(L)F1XK22
I2C SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)
DS40001365F-page 143
DS40001365F-page 144
2
1
4
1
5
0
7
A8
UA is set indicating that
the SSPADD needs to be
updated
SSPBUF is written with
contents of SSPSR
6
A9
8
9
(CKP does not reset to ‘0’ when SEN = 0)
UA (SSPSTAT)
SSPOV (SSPCON1)
CKP
3
1
Cleared by software
BF (SSPSTAT)
(PIR1)
SSPIF
1
SCL
S
1
ACK
R/W = 0
A7
2
4
A4
5
A3
6
A2
8
9
A0 ACK
UA is set indicating that
SSPADD needs to be
updated
Cleared by hardware
when SSPADD is updated
with low byte of address
7
A1
Cleared by software
3
A5
Dummy read of SSPBUF
to clear BF flag
1
A6
Receive Second Byte of Address
1
D7
4
5
6
7
Cleared by software
3
8
9
1
2
4
5
6
7
8
D1 D0
Cleared by software
3
D3 D2
Receive Data Byte
D1 D0 ACK D7 D6 D5 D4
Cleared by hardware when
SSPADD is updated with high
byte of address
2
D3 D2
Receive Data Byte
D6 D5 D4
Clock is held low until
update of SSPADD has
taken place
9
P
Bus master
terminates
transfer
SSPOV is set
because SSPBUF is
still full. ACK is not sent.
ACK
FIGURE 14-10:
SDA
Receive First Byte of Address
Clock is held low until
update of SSPADD has
taken place
PIC18(L)F1XK22
I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS)
2009-2016 Microchip Technology Inc.
2009-2016 Microchip Technology Inc.
CKP
UA
BF
SSPIF
1
SCL
S
1
2
1
4
1
5
0
6
7
A9 A8
UA is set indicating that
the SSPADD needs to be
updated
SSPBUF is written with
contents of SSPSR
3
1
8
9
ACK
R/W = 0
1
3
4
5
Cleared in software
2
7
UA is set indicating that
SSPADD needs to be
updated
Cleared by hardware when
SSPADD is updated with low
byte of address.
6
A6 A5 A4 A3 A2 A1
8
A0
Receive Second Byte of Address
Dummy read of SSPBUF
to clear BF flag
A7
9
ACK
Clock is held low until
update of SSPADD has
taken place
2
3
1
4
1
Cleared in software
1
1
5
0
6
7
A9 A8
Cleared by hardware when
SSPADD is updated with high
byte of address.
Dummy read of SSPBUF
to clear BF flag
Sr
1
Receive First Byte of Address
Bus Master
sends Restarts
condition
8
9
ACK
R/W=1
4
5
6
Cleared in software
3
Write of SSPBUF
2
9
P
Completion of
data transmission
clears BF flag
8
ACK
CKP is automatically cleared in hardware holding SCL low
CKP is set in software, initiates transmission
7
D4 D3 D2 D1 D0
Dummy read of SSPBUF
to clear BF flag
1
D7 D6 D5
Transmitting Data Byte
Clock is held low until
CKP is set to ‘1’
Bus Master
sends Stop
condition
FIGURE 14-11:
SDA
Receive First Byte of Address
Clock is held low until
update of SSPADD has
taken place
PIC18(L)F1XK22
I2C SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)
DS40001365F-page 145
PIC18(L)F1XK22
14.3.3.4
SSP Mask Register
This register must be initiated prior to setting
SSPM bits to select the I2C Slave mode (7-bit or
10-bit address).
2
An SSP Mask (SSPMSK) register is available in I C
Slave mode as a mask for the value held in the
SSPSR register during an address comparison
operation. A zero (‘0’) bit in the SSPMSK register has
the effect of making the corresponding bit in the
SSPSR register a “don’t care”.
The SSP Mask register is active during:
• 7-bit Address mode: address compare of A.
• 10-bit Address mode: address compare of A
only. The SSP mask has no effect during the
reception of the first (high) byte of the address.
This register is reset to all ‘1’s upon any Reset
condition and, therefore, has no effect on standard
SSP operation until written with a mask value.
REGISTER 14-6:
SSPMSK: SSP MASK REGISTER
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
MSK7
MSK6
MSK5
MSK4
MSK3
MSK2
MSK1
MSK0(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
MSK: Mask bits
1 = The received address bit n is compared to SSPADD to detect I2C address match
0 = The received address bit n is not used to detect I2C address match
bit 0
MSK: Mask bit for I2C Slave mode, 10-bit Address(1)
I2C Slave mode, 10-bit Address (SSPM = 0111):
1 = The received address bit 0 is compared to SSPADD to detect I2C address match
0 = The received address bit 0 is not used to detect I2C address match
Note 1: The MSK0 bit is used only in 10-bit Slave mode. In all other modes, this bit has no effect.
DS40001365F-page 146
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PIC18(L)F1XK22
SSPADD: MSSP ADDRESS AND BAUD RATE REGISTER (I2C MODE)
REGISTER 14-7:
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
ADD7
ADD6
ADD5
ADD4
ADD3
ADD2
ADD1
ADD0
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
Master mode:
bit 7-0
ADD: Baud Rate Clock Divider bits
SCL pin clock period = ((ADD + 1) *4)/FOSC
10-Bit Slave mode — Most Significant Address Byte:
bit 7-3
Not used: Unused for Most Significant Address Byte. Bit state of this register is a “don’t care.” Bit
pattern sent by master is fixed by I2C specification and must be equal to ‘11110’. However, those bits
are compared by hardware and are not affected by the value in this register.
bit 2-1
ADD: Two Most Significant bits of 10-bit address
bit 0
Not used: Unused in this mode. Bit state is a “don’t care.”
10-Bit Slave mode — Least Significant Address Byte:
bit 7-0
ADD: Eight Least Significant bits of 10-bit address
7-Bit Slave mode:
bit 7-1
ADD: 7-bit address
bit 0
Not used: Unused in this mode. Bit state is a “don’t care.”
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DS40001365F-page 147
PIC18(L)F1XK22
14.3.4
CLOCK STRETCHING
Both 7-bit and 10-bit Slave modes implement
automatic clock stretching during a transmit sequence.
The SEN bit of the SSPCON2 register allows clock
stretching to be enabled during receives. Setting SEN
will cause the SCL pin to be held low at the end of
each data receive sequence.
14.3.4.1
Clock Stretching for 7-bit Slave
Receive Mode (SEN = 1)
In 7-bit Slave Receive mode, on the falling edge of the
ninth clock at the end of the ACK sequence if the BF
bit is set, the CKP bit of the SSPCON1 register is
automatically cleared, forcing the SCL output to be
held low. The CKP being cleared to ‘0’ will assert the
SCL line low. The CKP bit must be set in the user’s
ISR before reception is allowed to continue. By holding
the SCL line low, the user has time to service the ISR
and read the contents of the SSPBUF before the
master device can initiate another data transfer
sequence. This will prevent buffer overruns from
occurring (see Figure 14-13).
Note 1: If the user reads the contents of the
SSPBUF before the falling edge of the
ninth clock, thus clearing the BF bit, the
CKP bit will not be cleared and clock
stretching will not occur.
2: The CKP bit can be set by software
regardless of the state of the BF bit. The
user should be careful to clear the BF bit
in the ISR before the next receive
sequence in order to prevent an overflow
condition.
14.3.4.2
14.3.4.3
Clock Stretching for 7-bit Slave
Transmit Mode
7-bit Slave Transmit mode implements clock stretching
by clearing the CKP bit after the falling edge of the
ninth clock. This occurs regardless of the state of the
SEN bit.
The user’s ISR must set the CKP bit before
transmission is allowed to continue. By holding the
SCL line low, the user has time to service the ISR and
load the contents of the SSPBUF before the master
device can initiate another data transfer sequence
(see Figure 14-9).
Note 1: If the user loads the contents of SSPBUF,
setting the BF bit before the falling edge
of the ninth clock, the CKP bit will not be
cleared and clock stretching will not
occur.
2: The CKP bit can be set by software
regardless of the state of the BF bit.
14.3.4.4
Clock Stretching for 10-bit Slave
Transmit Mode
In 10-bit Slave Transmit mode, clock stretching is
controlled during the first two address sequences by
the state of the UA bit, just as it is in 10-bit Slave
Receive mode. The first two addresses are followed
by a third address sequence which contains the
high-order bits of the 10-bit address and the R/W bit
set to ‘1’. After the third address sequence is
performed, the UA bit is not set, the module is now
configured in Transmit mode and clock stretching is
automatic with the hardware clearing CKP, as in 7-bit
Slave Transmit mode (see Figure 14-11).
Clock Stretching for 10-bit Slave
Receive Mode (SEN = 1)
In 10-bit Slave Receive mode during the address
sequence, clock stretching automatically takes place
but CKP is not cleared. During this time, if the UA bit is
set after the ninth clock, clock stretching is initiated.
The UA bit is set after receiving the upper byte of the
10-bit address and following the receive of the second
byte of the 10-bit address with the R/W bit cleared to
‘0’. The release of the clock line occurs upon updating
SSPADD. Clock stretching will occur on each data
receive sequence as described in 7-bit mode.
DS40001365F-page 148
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
14.3.4.5
Clock Synchronization and
the CKP bit
When the CKP bit is cleared, the SCL output is forced
to ‘0’. However, clearing the CKP bit will not assert the
SCL output low until the SCL output is already
sampled low. Therefore, the CKP bit will not assert the
SCL line until an external I2C master device has
already asserted the SCL line. The SCL output will
remain low until the CKP bit is set and all other
devices on the I2C bus have deasserted SCL. This
ensures that a write to the CKP bit will not violate the
minimum high time requirement for SCL (see
Figure 14-12).
FIGURE 14-12:
CLOCK SYNCHRONIZATION TIMING
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
SDA
DX
DX – 1
SCL
CKP
Master device
asserts clock
Master device
deasserts clock
WR
SSPCON1
2009-2016 Microchip Technology Inc.
DS40001365F-page 149
DS40001365F-page 150
CKP
SSPOV (SSPCON1)
BF (SSPSTAT)
(PIR1)
SSPIF
1
SCL
S
A7
2
A6
3
4
A4
5
A3
6
A2
Receiving Address
A5
7
A1
8
9
ACK
R/W = 0
3
4
D4
5
D3
Receiving Data
D5
Cleared by software
2
D6
If BF is cleared
prior to the falling
edge of the 9th clock,
CKP will not be reset
to ‘0’ and no clock
stretching will occur
SSPBUF is read
1
D7
6
D2
7
D1
9
ACK
1
D7
BF is set after falling
edge of the 9th clock,
CKP is reset to ‘0’ and
clock stretching occurs
8
D0
3
4
D4
5
D3
Receiving Data
D5
CKP
written
to ‘1’ in
software
2
D6
Clock is held low until
CKP is set to ‘1’
6
D2
7
D1
8
D0
Bus master
terminates
transfer
P
SSPOV is set
because SSPBUF is
still full. ACK is not sent.
9
ACK
Clock is not held low
because ACK = 1
FIGURE 14-13:
SDA
Clock is not held low
because buffer full bit is
clear prior to falling edge
of 9th clock
PIC18(L)F1XK22
I2C SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS)
2009-2016 Microchip Technology Inc.
2009-2016 Microchip Technology Inc.
2
1
UA (SSPSTAT)
SSPOV (SSPCON1)
CKP
3
1
4
1
5
0
6
7
A9 A8
8
UA is set indicating that
the SSPADD needs to be
updated
SSPBUF is written with
contents of SSPSR
Cleared by software
BF (SSPSTAT)
(PIR1)
SSPIF
1
SCL
S
1
9
ACK
R/W = 0
A7
2
4
A4
5
A3
6
A2
Cleared by software
3
A5
7
A1
8
A0
Note: An update of the SSPADD
register before the falling
edge of the ninth clock will
have no effect on UA and
UA will remain set.
UA is set indicating that
SSPADD needs to be
updated
Cleared by hardware when
SSPADD is updated with low
byte of address after falling edge
of ninth clock
Dummy read of SSPBUF
to clear BF flag
1
A6
Receive Second Byte of Address
9
ACK
2
4
5
6
7
9
Note: An update of the SSPADD register before
the falling edge of the ninth clock will have
no effect on UA and UA will remain set.
Cleared by hardware when
SSPADD is updated with high
byte of address after falling edge
of ninth clock
8
ACK
1
4
5
6
7
8
9
ACK
Bus master
terminates
transfer
P
Clock is not held low
because ACK = 1
SSPOV is set
because SSPBUF is
still full. ACK is not sent.
D1 D0
Cleared by software
3
CKP written to ‘1’
by software
2
D3 D2
Receive Data Byte
D7 D6 D5 D4
Clock is held low until
CKP is set to ‘1’
D1 D0
Cleared by software
3
D3 D2
Dummy read of SSPBUF
to clear BF flag
1
D7 D6 D5 D4
Receive Data Byte
Clock is held low until
update of SSPADD has
taken place
FIGURE 14-14:
SDA
Receive First Byte of Address
Clock is held low until
update of SSPADD has
taken place
PIC18(L)F1XK22
I2C SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 10-BIT ADDRESS)
DS40001365F-page 151
PIC18(L)F1XK22
14.3.5
GENERAL CALL ADDRESS
SUPPORT
If the general call address matches, the SSPSR is
transferred to the SSPBUF, the BF flag bit is set (eighth
bit) and on the falling edge of the ninth bit (ACK bit), the
SSPIF interrupt flag bit is set.
The addressing procedure for the I2C bus is such that
the first byte after the Start condition usually
determines which device will be the slave addressed by
the master. The exception is the general call address
which can address all devices. When this address is
used, all devices should, in theory, respond with an
Acknowledge.
When the interrupt is serviced, the source for the
interrupt can be checked by reading the contents of the
SSPBUF. The value can be used to determine if the
address was device specific or a general call address.
In 10-bit mode, the SSPADD is required to be updated
for the second half of the address to match and the UA
bit of the SSPSTAT register is set. If the general call
address is sampled when the GCEN bit is set, while the
slave is configured in 10-bit Address mode, then the
second half of the address is not necessary, the UA bit
will not be set and the slave will begin receiving data
after the Acknowledge (Figure 14-15).
The general call address is one of eight addresses
reserved for specific purposes by the I2C protocol. It
consists of all ‘0’s with R/W = 0.
The general call address is recognized when the
GCEN bit of the SSPCON2 is set. Following a Start bit
detect, eight bits are shifted into the SSPSR and the
address is compared against the SSPADD. It is also
compared to the general call address and fixed in
hardware.
FIGURE 14-15:
SLAVE MODE GENERAL CALL ADDRESS SEQUENCE
(7 OR 10-BIT ADDRESS MODE)
Address is compared to General Call Address
after ACK, set interrupt
SCL
S
1
2
3
4
5
Receiving Data
R/W = 0
General Call Address
SDA
ACK D7
6
7
8
9
1
ACK
D6
D5
D4
D3
D2
D1
D0
2
3
4
5
6
7
8
9
SSPIF
BF (SSPSTAT)
Cleared by software
SSPBUF is read
SSPOV (SSPCON1)
‘0’
GCEN (SSPCON2)
‘1’
DS40001365F-page 152
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
MASTER MODE
Note:
Master mode is enabled by setting and clearing the
appropriate SSPM bits in SSPCON1 and by setting the
SSPEN bit. In Master mode, the SCL and SDA lines
are manipulated by the MSSP hardware.
Master mode of operation is supported by interrupt
generation on the detection of the Start and Stop
conditions. The Stop (P) and Start (S) bits are cleared
from a Reset or when the MSSP module is disabled.
Control of the I 2C bus may be taken when the P bit is
set, or the bus is Idle, with both the S and P bits clear.
The following events will cause the SSP Interrupt Flag
bit, SSPIF, to be set (SSP interrupt, if enabled):
In Firmware Controlled Master mode, user code
conducts all I 2C bus operations based on Start and
Stop bit conditions.
•
•
•
•
•
Once Master mode is enabled, the user has six
options.
1.
2.
3.
4.
5.
6.
Assert a Start condition on SDA and SCL.
Assert a Repeated Start condition on SDA and
SCL.
Write to the SSPBUF register initiating
transmission of data/address.
Configure the I2C port to receive data.
Generate an Acknowledge condition at the end
of a received byte of data.
Generate a Stop condition on SDA and SCL.
FIGURE 14-16:
The MSSP module, when configured in
I2C Master mode, does not allow queueing
of events. For instance, the user is not
allowed to initiate a Start condition and
immediately write the SSPBUF register to
initiate transmission before the Start
condition is complete. In this case, the
SSPBUF will not be written to and the
WCOL bit will be set, indicating that a write
to the SSPBUF did not occur.
Start condition
Stop condition
Data transfer byte transmitted/received
Acknowledge transmit
Repeated Start
MSSP BLOCK DIAGRAM (I2C MASTER MODE)
Internal
Data Bus
Read
SSPM
SSPADD
Write
SSPBUF
SDA
Baud
Rate
Generator
Shift
Clock
SDA In
SCL In
Bus Collision
2009-2016 Microchip Technology Inc.
LSb
Start bit, Stop bit,
Acknowledge
Generate
Start bit Detect
Stop bit Detect
Write Collision Detect
Clock Arbitration
State Counter for
end of XMIT/RCV
Clock Cntl
SCL
Receive Enable
SSPSR
MSb
Clock Arbitrate/WCOL Detect
(hold off clock source)
14.3.6
Set/Reset, S, P, WCOL
Set SSPIF, BCLIF
Reset ACKSTAT, PEN
DS40001365F-page 153
PIC18(L)F1XK22
14.3.6.1
I2C Master Mode Operation
The master device generates all of the serial clock
pulses and the Start and Stop conditions. A transfer is
ended with a Stop condition or with a Repeated Start
condition. Since the Repeated Start condition is also
the beginning of the next serial transfer, the I2C bus will
not be released.
In Master Transmitter mode, serial data is output
through SDA, while SCL outputs the serial clock. The
first byte transmitted contains the slave address of the
receiving device (seven bits) and the Read/Write (R/W)
bit. In this case, the R/W bit will be logic ‘0’. Serial data
is transmitted eight bits at a time. After each byte is
transmitted, an Acknowledge bit is received. Start and
Stop conditions are output to indicate the beginning
and the end of a serial transfer.
In Master Receive mode, the first byte transmitted
contains the slave address of the transmitting device
(7 bits) and the R/W bit. In this case, the R/W bit will be
logic ‘1’. Thus, the first byte transmitted is a 7-bit slave
address followed by a ‘1’ to indicate the receive bit.
Serial data is received via SDA, while SCL outputs the
serial clock. Serial data is received 8 bits at a time. After
each byte is received, an Acknowledge bit is
transmitted. Start and Stop conditions indicate the
beginning and end of transmission.
A Baud Rate Generator is used to set the clock
frequency output on SCL. See Section 14.3.7 “Baud
Rate” for more detail.
DS40001365F-page 154
A typical transmit sequence would go as follows:
1.
The user generates a Start condition by setting
the SEN bit of the SSPCON2 register.
2. SSPIF is set. The MSSP module will wait the
required start time before any other operation
takes place.
3. The user loads the SSPBUF with the slave
address to transmit.
4. Address is shifted out the SDA pin until all 8 bits
are transmitted.
5. The MSSP module shifts in the ACK bit from the
slave device and writes its value into the
ACKSTAT bit of the SSPCON2 register.
6. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the SSPIF
bit.
7. The user loads the SSPBUF with eight bits of
data.
8. Data is shifted out the SDA pin until all 8 bits are
transmitted.
9. The MSSP module shifts in the ACK bit from the
slave device and writes its value into the
ACKSTAT bit of the SSPCON2 register.
10. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the SSPIF
bit.
11. The user generates a Stop condition by setting
the PEN bit of the SSPCON2 register.
12. Interrupt is generated once the Stop condition is
complete.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
14.3.7
BAUD RATE
2
In I C Master mode, the Baud Rate Generator (BRG)
reload value is placed in the SSPADD register
(Figure 14-17). When a write occurs to SSPBUF, the
Baud Rate Generator will automatically begin counting.
Table 14-3 demonstrates clock rates based on
instruction cycles and the BRG value loaded into
SSPADD.
EQUATION 14-1:
Once the given operation is complete (i.e.,
transmission of the last data bit is followed by ACK), the
internal clock will automatically stop counting and the
SCL pin will remain in its last state.
FIGURE 14-17:
FOSC
FSCL = --------------------------------------------- SSPADD + 1 4
BAUD RATE GENERATOR BLOCK DIAGRAM
SSPM
SSPM
Reload
SCL
Control
CLKOUT
SSPADD
Reload
BRG Down Counter
FOSC/2
I2C CLOCK RATE W/BRG
TABLE 14-3:
Note 1:
CLOCK RATES
FOSC
FCY
BRG Value
FSCL
(2 Rollovers of BRG)
48 MHz
12 MHz
0Bh
1 MHz(1)
48 MHz
12 MHz
1Dh
400 kHz
48 MHz
12 MHz
77h
100 kHz
40 MHz
10 MHz
18h
400 kHz(1)
40 MHz
10 MHz
1Fh
312.5 kHz
40 MHz
10 MHz
63h
100 kHz
16 MHz
4 MHz
09h
400 kHz(1)
16 MHz
4 MHz
0Ch
308 kHz
16 MHz
4 MHz
27h
100 kHz
4 MHz
1 MHz
02h
333 kHz(1)
4 MHz
1 MHz
09h
100 kHz
4 MHz
1 MHz
00h
1 MHz(1)
2
2
The I C interface does not conform to the 400 kHz I C specification (which applies to rates greater than
100 kHz) in all details, but may be used with care where higher rates are required by the application.
2009-2016 Microchip Technology Inc.
DS40001365F-page 155
PIC18(L)F1XK22
14.3.7.1
Clock Arbitration
Clock arbitration occurs when the master, during any
receive, transmit or Repeated Start/Stop condition,
deasserts the SCL pin (SCL allowed to float high).
When the SCL pin is allowed to float high, the Baud
Rate Generator (BRG) is suspended from counting
until the SCL pin is actually sampled high. When the
SCL pin is sampled high, the Baud Rate Generator is
reloaded with the contents of SSPADD and
begins counting. This ensures that the SCL high time
will always be at least one BRG rollover count in the
event that the clock is held low by an external device
(Figure 14-18).
FIGURE 14-18:
BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
SDA
DX
DX – 1
SCL deasserted but slave holds
SCL low (clock arbitration)
SCL allowed to transition high
SCL
BRG decrements on
Q2 and Q4 cycles
BRG
Value
03h
02h
01h
00h (hold off)
03h
02h
SCL is sampled high, reload takes
place and BRG starts its count
BRG
Reload
DS40001365F-page 156
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PIC18(L)F1XK22
14.3.8
I2C MASTER MODE START
CONDITION TIMING
Note:
To initiate a Start condition, the user sets the Start
Enable bit, SEN bit of the SSPCON2 register. If the
SDA and SCL pins are sampled high, the Baud Rate
Generator is reloaded with the contents of
SSPADD and starts its count. If SCL and SDA are
both sampled high when the Baud Rate Generator
times out (TBRG), the SDA pin is driven low. The action
of the SDA being driven low while SCL is high is the
Start condition and causes the S bit of the SSPSTAT1
register to be set. Following this, the Baud Rate
Generator is reloaded with the contents of
SSPADD and resumes its count. When the Baud
Rate Generator times out (TBRG), the SEN bit of the
SSPCON2 register will be automatically cleared by
hardware; the Baud Rate Generator is suspended,
leaving the SDA line held low and the Start condition is
complete.
FIGURE 14-19:
14.3.8.1
If at the beginning of the Start condition,
the SDA and SCL pins are already
sampled low, or if during the Start
condition, the SCL line is sampled low
before the SDA line is driven low, a bus
collision occurs, the Bus Collision Interrupt
Flag, BCLIF, is set, the Start condition is
aborted and the I2C module is reset into its
Idle state.
WCOL Status Flag
If the user writes the SSPBUF when a Start sequence
is in progress, the WCOL is set and the contents of the
buffer are unchanged (the write doesn’t occur).
Note:
Because queuing of events is not allowed,
writing to the lower five bits of SSPCON2
is disabled until the Start condition is
complete.
FIRST START BIT TIMING
Write to SEN bit occurs here
Set S bit (SSPSTAT)
SDA = 1,
SCL = 1
TBRG
At completion of Start bit,
hardware clears SEN bit
and sets SSPIF bit
TBRG
Write to SSPBUF occurs here
1st bit
SDA
2nd bit
TBRG
SCL
TBRG
S
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DS40001365F-page 157
PIC18(L)F1XK22
14.3.9
I2C MASTER MODE REPEATED
START CONDITION TIMING
Note 1: If RSEN is programmed while any other
event is in progress, it will not take effect.
A Repeated Start condition occurs when the RSEN bit
of the SSPCON2 register is programmed high and the
I2C logic module is in the Idle state. When the RSEN bit
is set, the SCL pin is asserted low. When the SCL pin
is sampled low, the Baud Rate Generator is loaded and
begins counting. The SDA pin is released (brought
high) for one Baud Rate Generator count (TBRG). When
the Baud Rate Generator times out, if SDA is sampled
high, the SCL pin will be deasserted (brought high).
When SCL is sampled high, the Baud Rate Generator
is reloaded and begins counting. SDA and SCL must
be sampled high for one TBRG. This action is then
followed by assertion of the SDA pin (SDA = 0) for one
TBRG while SCL is high. Following this, the RSEN bit of
the SSPCON2 register will be automatically cleared
and the Baud Rate Generator will not be reloaded,
leaving the SDA pin held low. As soon as a Start
condition is detected on the SDA and SCL pins, the S
bit of the SSPSTAT register will be set. The SSPIF bit
will not be set until the Baud Rate Generator has timed
out.
2: A bus collision during the Repeated Start
condition occurs if:
• SDA is sampled low when SCL goes
from low-to-high.
• SCL goes low before SDA is
asserted low. This may indicate that
another master is attempting to
transmit a data ‘1’.
Immediately following the SSPIF bit getting set, the user
may write the SSPBUF with the 7-bit address in 7-bit
mode or the default first address in 10-bit mode. After the
first eight bits are transmitted and an ACK is received,
the user may then transmit an additional eight bits of
address (10-bit mode) or eight bits of data (7-bit mode).
14.3.9.1
If the user writes the SSPBUF when a Repeated Start
sequence is in progress, the WCOL is set and the
contents of the buffer are unchanged (the write doesn’t
occur).
Note:
FIGURE 14-20:
WCOL Status Flag
Because queueing of events is not
allowed, writing of the lower 5 bits of SSPCON2 is disabled until the Repeated Start
condition is complete.
REPEAT START CONDITION WAVEFORM
Write to SSPCON2
occurs here.
SDA = 1,
SCL (no change).
S bit set by hardware
SDA = 1,
SCL = 1
TBRG
TBRG
At completion of Start bit,
hardware clears RSEN bit
and sets SSPIF
TBRG
1st bit
SDA
RSEN bit set by hardware
on falling edge of ninth clock,
end of Xmit
Write to SSPBUF occurs here
TBRG
SCL
TBRG
Sr = Repeated Start
DS40001365F-page 158
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
14.3.10
I2C MASTER MODE
TRANSMISSION
Transmission of a data byte, a 7-bit address or the
other half of a 10-bit address is accomplished by simply
writing a value to the SSPBUF register. This action will
set the Buffer Full flag bit, BF, and allow the Baud Rate
Generator to begin counting and start the next
transmission. Each bit of address/data will be shifted
out onto the SDA pin after the falling edge of SCL is
asserted (see data hold time specification
parameter SP106). SCL is held low for one Baud Rate
Generator rollover count (TBRG). Data should be valid
before SCL is released high (see data setup time
specification parameter SP107). When the SCL pin is
released high, it is held that way for TBRG. The data on
the SDA pin must remain stable for that duration and
some hold time after the next falling edge of SCL. After
the eighth bit is shifted out (the falling edge of the eighth
clock), the BF flag is cleared and the master releases
SDA. This allows the slave device being addressed to
respond with an ACK bit during the ninth bit time if an
address match occurred, or if data was received
properly. The status of ACK is written into the ACKDT
bit on the falling edge of the ninth clock. If the master
receives an Acknowledge, the Acknowledge Status bit,
ACKSTAT, is cleared. If not, the bit is set. After the ninth
clock, the SSPIF bit is set and the master clock (Baud
Rate Generator) is suspended until the next data byte
is loaded into the SSPBUF, leaving SCL low and SDA
unchanged (Figure 14-21).
After the write to the SSPBUF, each bit of the address
will be shifted out on the falling edge of SCL until all
seven address bits and the R/W bit are completed. On
the falling edge of the eighth clock, the master will
deassert the SDA pin, allowing the slave to respond
with an Acknowledge. On the falling edge of the ninth
clock, the master will sample the SDA pin to see if the
address was recognized by a slave. The status of the
ACK bit is loaded into the ACKSTAT Status bit of the
SSPCON2 register. Following the falling edge of the
ninth clock transmission of the address, the SSPIF is
set, the BF flag is cleared and the Baud Rate Generator
is turned off until another write to the SSPBUF takes
place, holding SCL low and allowing SDA to float.
14.3.10.1
BF Status Flag
In Transmit mode, the BF bit of the SSPSTAT register
is set when the CPU writes to SSPBUF and is cleared
when all 8 bits are shifted out.
14.3.10.2
14.3.10.3
ACKSTAT Status Flag
In Transmit mode, the ACKSTAT bit of the SSPCON2
register is cleared when the slave has sent an
Acknowledge (ACK = 0) and is set when the slave
does not Acknowledge (ACK = 1). A slave sends an
Acknowledge when it has recognized its address
(including a general call), or when the slave has
properly received its data.
14.3.11
I2C MASTER MODE RECEPTION
Master mode reception is enabled by programming the
Receive Enable bit, RCEN bit of the SSPCON2
register.
Note:
The MSSP module must be in an Idle
state before the RCEN bit is set or the
RCEN bit will be disregarded.
The Baud Rate Generator begins counting and on each
rollover, the state of the SCL pin changes
(high-to-low/low-to-high) and data is shifted into the
SSPSR. After the falling edge of the eighth clock, the
receive enable flag is automatically cleared, the
contents of the SSPSR are loaded into the SSPBUF,
the BF flag bit is set, the SSPIF flag bit is set and the
Baud Rate Generator is suspended from counting,
holding SCL low. The MSSP is now in Idle state
awaiting the next command. When the buffer is read by
the CPU, the BF flag bit is automatically cleared. The
user can then send an Acknowledge bit at the end of
reception by setting the Acknowledge Sequence
Enable, ACKEN bit of the SSPCON2 register.
14.3.11.1
BF Status Flag
In receive operation, the BF bit is set when an address
or data byte is loaded into SSPBUF from SSPSR. It is
cleared when the SSPBUF register is read.
14.3.11.2
SSPOV Status Flag
In receive operation, the SSPOV bit is set when 8 bits
are received into the SSPSR and the BF flag bit is
already set from a previous reception.
14.3.11.3
WCOL Status Flag
If the user writes the SSPBUF when a receive is
already in progress (i.e., SSPSR is still shifting in a data
byte), the WCOL bit is set and the contents of the buffer
are unchanged (the write doesn’t occur).
WCOL Status Flag
If the user writes the SSPBUF when a transmit is
already in progress (i.e., SSPSR is still shifting out a
data byte), the WCOL is set and the contents of the
buffer are unchanged (the write doesn’t occur).
WCOL must be cleared by software before the next
transmission.
2009-2016 Microchip Technology Inc.
DS40001365F-page 159
DS40001365F-page 160
S
R/W
PEN
SEN
BF (SSPSTAT)
SSPIF
SCL
SDA
A6
A5
A4
A3
A2
A1
3
4
5
Cleared by software
2
6
7
8
9
After Start condition, SEN cleared by hardware
SSPBUF written
1
D7
1
SCL held low
while CPU
responds to SSPIF
ACK = 0
R/W = 0
SSPBUF written with 7-bit address and R/W
start transmit
A7
Transmit Address to Slave
3
D5
4
D4
5
D3
6
D2
7
D1
8
D0
SSPBUF is written by software
Cleared by software service routine
from SSP interrupt
2
D6
Transmitting Data or Second Half
of 10-bit Address
From slave, clear ACKSTAT bit SSPCON2
P
Cleared by software
9
ACK
ACKSTAT in
SSPCON2 = 1
FIGURE 14-21:
SEN = 0
Write SSPCON2 SEN = 1
Start condition begins
PIC18(L)F1XK22
I 2C MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS)
2009-2016 Microchip Technology Inc.
2009-2016 Microchip Technology Inc.
RCEN
ACKEN
SSPOV
BF
(SSPSTAT)
SDA = 0, SCL = 1
while CPU
responds to SSPIF
SSPIF
S
1
A7
2
4
5
6
Cleared by software
3
A6 A5 A4 A3 A2
Transmit Address to Slave
7
A1
8
ACK
2
3
5
6
7
8
D0
9
ACK
2
3
4
RCEN cleared
automatically
5
6
7
Cleared by software
Set SSPIF interrupt
at end of Acknowledge
sequence
Data shifted in on falling edge of CLK
1
ACK from Master
SDA = ACKDT = 0
Cleared in
software
Set SSPIF at end
of receive
9
ACK is not sent
ACK
P
Set SSPIF interrupt
at end of Acknowledge sequence
Bus master
terminates
transfer
Set P bit
(SSPSTAT)
and SSPIF
PEN bit = 1
written here
SSPOV is set because
SSPBUF is still full
8
D0
RCEN cleared
automatically
D7 D6 D5 D4 D3 D2 D1
RCEN cleared
automatically
Set ACKEN, start Acknowledge sequence
SDA = ACKDT = 1
Receiving Data from Slave
RCEN = 1, start
next receive
ACK from Master
SDA = ACKDT = 0
Last bit is shifted into SSPSR and
contents are unloaded into SSPBUF
Cleared by software
Set SSPIF interrupt
at end of receive
4
Cleared by software
1
D7 D6 D5 D4 D3 D2 D1
Receiving Data from Slave
RCEN cleared
automatically
Master configured as a receiver
by programming SSPCON2 (RCEN = 1)
9
R/W = 0
ACK from Slave
Master configured as a receiver
by programming SSPCON2 (RCEN = 1)
FIGURE 14-22:
SCL
SDA
SEN = 0
Write to SSPBUF occurs here,
start XMIT
Write to SSPCON2 (SEN = 1),
begin Start condition
Write to SSPCON2
to start Acknowledge sequence
SDA = ACKDT (SSPCON2) = 0
PIC18(L)F1XK22
I 2C MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)
DS40001365F-page 161
PIC18(L)F1XK22
14.3.12
ACKNOWLEDGE SEQUENCE
TIMING
14.3.13
A Stop bit is asserted on the SDA pin at the end of a
receive/transmit by setting the Stop Sequence Enable
bit, PEN bit of the SSPCON2 register. At the end of a
receive/transmit, the SCL line is held low after the
falling edge of the ninth clock. When the PEN bit is set,
the master will assert the SDA line low. When the SDA
line is sampled low, the Baud Rate Generator is
reloaded and counts down to ‘0’. When the Baud Rate
Generator times out, the SCL pin will be brought high
and one TBRG (Baud Rate Generator rollover count)
later, the SDA pin will be deasserted. When the SDA
pin is sampled high while SCL is high, the P bit of the
SSPSTAT register is set. A TBRG later, the PEN bit is
cleared and the SSPIF bit is set (Figure 14-24).
An Acknowledge sequence is enabled by setting the
Acknowledge Sequence Enable bit, ACKEN bit of the
SSPCON2 register. When this bit is set, the SCL pin is
pulled low and the contents of the Acknowledge data bit
are presented on the SDA pin. If the user wishes to
generate an Acknowledge, then the ACKDT bit should
be cleared. If not, the user should set the ACKDT bit
before starting an Acknowledge sequence. The Baud
Rate Generator then counts for one rollover period
(TBRG) and the SCL pin is deasserted (pulled high).
When the SCL pin is sampled high (clock arbitration),
the Baud Rate Generator counts for TBRG. The SCL pin
is then pulled low. Following this, the ACKEN bit is
automatically cleared, the Baud Rate Generator is
turned off and the MSSP module then goes into Idle
mode (Figure 14-23).
14.3.12.1
14.3.13.1
WCOL Status Flag
If the user writes the SSPBUF when a Stop sequence
is in progress, then the WCOL bit is set and the
contents of the buffer are unchanged (the write doesn’t
occur).
WCOL Status Flag
If the user writes the SSPBUF when an Acknowledge
sequence is in progress, then WCOL is set and the
contents of the buffer are unchanged (the write doesn’t
occur).
FIGURE 14-23:
STOP CONDITION TIMING
ACKNOWLEDGE SEQUENCE WAVEFORM
Acknowledge sequence starts here,
write to SSPCON2
ACKEN = 1, ACKDT = 0
ACKEN automatically cleared
TBRG
TBRG
SDA
SCL
D0
ACK
8
9
SSPIF
SSPIF set at
the end of receive
Cleared in
software
Cleared in
software
SSPIF set at the end
of Acknowledge sequence
Note: TBRG = one Baud Rate Generator period.
DS40001365F-page 162
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 14-24:
STOP CONDITION RECEIVE OR TRANSMIT MODE
SCL = 1 for TBRG, followed by SDA = 1 for TBRG
after SDA sampled high. P bit (SSPSTAT) is set.
Write to SSPCON2,
set PEN
PEN bit (SSPCON2) is cleared by
hardware and the SSPIF bit is set
Falling edge of
9th clock
TBRG
SCL
SDA
ACK
P
TBRG
TBRG
TBRG
SCL brought high after TBRG
SDA asserted low before rising edge of clock
to setup Stop condition
Note: TBRG = one Baud Rate Generator period.
14.3.14
SLEEP OPERATION
2
While in Sleep mode, the I C Slave module can receive
addresses or data and when an address match or
complete byte transfer occurs, wake the processor
from Sleep (if the MSSP interrupt is enabled).
14.3.15
EFFECTS OF A RESET
A Reset disables the MSSP module and terminates the
current transfer.
14.3.16
MULTI-MASTER MODE
In Multi-Master mode, the interrupt generation on the
detection of the Start and Stop conditions allows the
determination of when the bus is free. The Stop (P) and
Start (S) bits are cleared from a Reset or when the
MSSP module is disabled. Control of the I 2C bus may
be taken when the P bit of the SSPSTAT register is set,
or the bus is Idle, with both the S and P bits clear. When
the bus is busy, enabling the SSP interrupt will
generate the interrupt when the Stop condition occurs.
In multi-master operation, the SDA line must be
monitored for arbitration to see if the signal level is the
expected output level. This check is performed by
hardware with the result placed in the BCLIF bit.
The states where arbitration can be lost are:
•
•
•
•
•
Address Transfer
Data Transfer
A Start Condition
A Repeated Start Condition
An Acknowledge Condition
14.3.17
MULTI -MASTER COMMUNICATION,
BUS COLLISION AND BUS
ARBITRATION
Multi-Master mode support is achieved by bus
arbitration. When the master outputs address/data bits
onto the SDA pin, arbitration takes place when the
master outputs a ‘1’ on SDA, by letting SDA float high
and another master asserts a ‘0’. When the SCL pin
floats high, data should be stable. If the expected data
on SDA is a ‘1’ and the data sampled on the SDA pin =
0, then a bus collision has taken place. The master will
set the Bus Collision Interrupt Flag, BCLIF and reset
the I2C port to its Idle state (Figure 14-25).
If a transmit was in progress when the bus collision
occurred, the transmission is halted, the BF flag is
cleared, the SDA and SCL lines are deasserted and the
SSPBUF can be written to. When the user services the
bus collision Interrupt Service Routine and if the I2C
bus is free, the user can resume communication by
asserting a Start condition.
If a Start, Repeated Start, Stop or Acknowledge
condition was in progress when the bus collision
occurred, the condition is aborted, the SDA and SCL
lines are deasserted and the respective control bits in
the SSPCON2 register are cleared. When the user
services the bus collision Interrupt Service Routine and
if the I2C bus is free, the user can resume
communication by asserting a Start condition.
The master will continue to monitor the SDA and SCL
pins. If a Stop condition occurs, the SSPIF bit will be set.
A write to the SSPBUF will start the transmission of
data at the first data bit, regardless of where the
transmitter left off when the bus collision occurred.
In Multi-Master mode, the interrupt generation on the
detection of Start and Stop conditions allows the
determination of when the bus is free. Control of the I2C
bus can be taken when the P bit is set in the SSPSTAT
register, or the bus is Idle and the S and P bits are
cleared.
2009-2016 Microchip Technology Inc.
DS40001365F-page 163
PIC18(L)F1XK22
FIGURE 14-25:
BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE
Data changes
while SCL = 0
SDA line pulled low
by another source
SDA released
by master
Sample SDA. While SCL is high,
data doesn’t match what is driven
by the master.
Bus collision has occurred.
SDA
SCL
Set bus collision
interrupt (BCLIF)
BCLIF
DS40001365F-page 164
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
14.3.17.1
Bus Collision During a Start
Condition
During a Start condition, a bus collision occurs if:
a)
b)
SDA or SCL are sampled low at the beginning of
the Start condition (Figure 14-26).
SCL is sampled low before SDA is asserted low
(Figure 14-27).
During a Start condition, both the SDA and the SCL
pins are monitored.
If the SDA pin is sampled low during this count, the
BRG is reset and the SDA line is asserted early
(Figure 14-28). If, however, a ‘1’ is sampled on the SDA
pin, the SDA pin is asserted low at the end of the BRG
count. The Baud Rate Generator is then reloaded and
counts down to 0; if the SCL pin is sampled as ‘0’
during this time, a bus collision does not occur. At the
end of the BRG count, the SCL pin is asserted low.
Note:
If the SDA pin is already low, or the SCL pin is already
low, then all of the following occur:
• the Start condition is aborted,
• the BCLIF flag is set and
• the MSSP module is reset to its Idle state
(Figure 14-26).
The Start condition begins with the SDA and SCL pins
deasserted. When the SDA pin is sampled high, the
Baud Rate Generator is loaded and counts down. If the
SCL pin is sampled low while SDA is high, a bus
collision occurs because it is assumed that another
master is attempting to drive a data ‘1’ during the Start
condition.
FIGURE 14-26:
The reason that bus collision is not a
factor during a Start condition is that no
two bus masters can assert a Start
condition at the exact same time.
Therefore, one master will always assert
SDA before the other. This condition does
not cause a bus collision because the two
masters must be allowed to arbitrate the
first address following the Start condition.
If the address is the same, arbitration
must be allowed to continue into the data
portion, Repeated Start or Stop
conditions.
BUS COLLISION DURING START CONDITION (SDA ONLY)
SDA goes low before the SEN bit is set.
Set BCLIF,
S bit and SSPIF set because
SDA = 0, SCL = 1.
SDA
SCL
Set SEN, enable Start
condition if SDA = 1, SCL = 1
SEN cleared automatically because of bus collision.
SSP module reset into Idle state.
SEN
BCLIF
SDA sampled low before
Start condition. Set BCLIF.
S bit and SSPIF set because
SDA = 0, SCL = 1.
SSPIF and BCLIF are
cleared by software
S
SSPIF
SSPIF and BCLIF are
cleared by software
2009-2016 Microchip Technology Inc.
DS40001365F-page 165
PIC18(L)F1XK22
FIGURE 14-27:
BUS COLLISION DURING START CONDITION (SCL = 0)
SDA = 0, SCL = 1
TBRG
TBRG
SDA
Set SEN, enable Start
sequence if SDA = 1, SCL = 1
SCL
SCL = 0 before SDA = 0,
bus collision occurs. Set BCLIF.
SEN
SCL = 0 before BRG time-out,
bus collision occurs. Set BCLIF.
BCLIF
Interrupt cleared
by software
S
‘0’
‘0’
SSPIF
‘0’
‘0’
FIGURE 14-28:
BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION
SDA = 0, SCL = 1
Set S
Less than TBRG
SDA
SCL
TBRG
SDA pulled low by other master.
Reset BRG and assert SDA.
S
SCL pulled low after BRG
time-out
SEN
BCLIF
Set SSPIF
Set SEN, enable START
sequence if SDA = 1, SCL = 1
‘0’
S
SSPIF
SDA = 0, SCL = 1,
set SSPIF
DS40001365F-page 166
Interrupts cleared
by software
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
14.3.17.2
Bus Collision During a Repeated
Start Condition
If SDA is low, a bus collision has occurred (i.e., another
master is attempting to transmit a data ‘0’, Figure 14-29).
If SDA is sampled high, the BRG is reloaded and begins
counting. If SDA goes from high-to-low before the BRG
times out, no bus collision occurs because no two
masters can assert SDA at exactly the same time.
During a Repeated Start condition, a bus collision
occurs if:
a)
b)
A low level is sampled on SDA when SCL goes
from low level to high level.
SCL goes low before SDA is asserted low,
indicating that another master is attempting to
transmit a data ‘1’.
If SCL goes from high-to-low before the BRG times out
and SDA has not already been asserted, a bus collision
occurs. In this case, another master is attempting to
transmit a data ‘1’ during the Repeated Start condition,
see Figure 14-30.
When the user deasserts SDA and the pin is allowed to
float high, the BRG is loaded with SSPADD and counts
down to 0. The SCL pin is then deasserted and when
sampled high, the SDA pin is sampled.
FIGURE 14-29:
If, at the end of the BRG time-out, both SCL and SDA
are still high, the SDA pin is driven low and the BRG is
reloaded and begins counting. At the end of the count,
regardless of the status of the SCL pin, the SCL pin is
driven low and the Repeated Start condition is
complete.
BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)
SDA
SCL
Sample SDA when SCL goes high.
If SDA = 0, set BCLIF and release SDA and SCL.
RSEN
BCLIF
Cleared by software
‘0’
S
‘0’
SSPIF
FIGURE 14-30:
BUS COLLISION DURING REPEATED START CONDITION (CASE 2)
TBRG
TBRG
SDA
SCL
BCLIF
SCL goes low before SDA,
set BCLIF. Release SDA and SCL.
Interrupt cleared
by software
RSEN
S
‘0’
SSPIF
2009-2016 Microchip Technology Inc.
DS40001365F-page 167
PIC18(L)F1XK22
14.3.17.3
Bus Collision During a Stop
Condition
The Stop condition begins with SDA asserted low.
When SDA is sampled low, the SCL pin is allowed to
float. When the pin is sampled high (clock arbitration),
the Baud Rate Generator is loaded with SSPADD and
counts down to 0. After the BRG times out, SDA is
sampled. If SDA is sampled low, a bus collision has
occurred. This is due to another master attempting to
drive a data ‘0’ (Figure 14-31). If the SCL pin is
sampled low before SDA is allowed to float high, a bus
collision occurs. This is another case of another master
attempting to drive a data ‘0’ (Figure 14-32).
Bus collision occurs during a Stop condition if:
a)
b)
After the SDA pin has been deasserted and
allowed to float high, SDA is sampled low after
the BRG has timed out.
After the SCL pin is deasserted, SCL is sampled
low before SDA goes high.
FIGURE 14-31:
BUS COLLISION DURING A STOP CONDITION (CASE 1)
TBRG
TBRG
TBRG
SDA
SDA sampled
low after TBRG,
set BCLIF
SDA asserted low
SCL
PEN
BCLIF
P
‘0’
SSPIF
‘0’
FIGURE 14-32:
BUS COLLISION DURING A STOP CONDITION (CASE 2)
TBRG
TBRG
TBRG
SDA
Assert SDA
SCL
SCL goes low before SDA goes high,
set BCLIF
PEN
BCLIF
P
‘0’
SSPIF
‘0’
DS40001365F-page 168
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 14-4:
Name
SUMMARY OF REGISTERS ASSOCIATED WITH I2C
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
248
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
IPR2
OSCFIP
C1IP
C2IP
EEIP
BCLIP
—
TMR3IP
—
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
PIE2
OSCFIE
C1IE
C2IE
EEIE
BCLIE
—
TMR3IE
—
248
PIR1
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
OSCFIF
C1IF
C2IF
EEIF
BCLIF
—
TMR3IF
—
248
PIR2
SSPADD
SSP Address Register in I2C Slave Mode. SSP Baud Rate Reload Register in I2C Master Mode.
246
SSPBUF
SSP Receive Buffer/Transmit Register
246
SSPCON1
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
246
SSPCON2
GCEN
ACKSTAT
ACKDT
ACKEN
RCEN
PEN
RSEN
SEN
246
SSPMSK
MSK7
MSK6
MSK5
MSK4
MSK3
MSK2
MSK1
MSK0
248
SSPSTAT
SMP
CKE
D/A
P
S
R/W
UA
BF
246
TRISB7
TRISB6
TRISB5
TRISB4
—
—
—
—
248
TRISB
Legend:
— = unimplemented, read as ‘0’. Shaded cells are not used by I2C.
2009-2016 Microchip Technology Inc.
DS40001365F-page 169
PIC18(L)F1XK22
15.0
The EUSART module includes the following capabilities:
ENHANCED UNIVERSAL
SYNCHRONOUS
ASYNCHRONOUS RECEIVER
TRANSMITTER (EUSART)
•
•
•
•
•
•
•
•
•
•
The Enhanced Universal Synchronous Asynchronous
Receiver Transmitter (EUSART) module is a serial I/O
communications peripheral. It contains all the clock
generators, shift registers and data buffers necessary
to perform an input or output serial data transfer
independent of device program execution. The
EUSART, also known as a Serial Communications
Interface (SCI), can be configured as a full-duplex
asynchronous system or half-duplex synchronous
system.
Full-Duplex
mode
is
useful
for
communications with peripheral systems, such as CRT
terminals and personal computers. Half-Duplex
Synchronous mode is intended for communications
with peripheral devices, such as A/D or D/A integrated
circuits, serial EEPROMs or other microcontrollers.
These devices typically do not have internal clocks for
baud rate generation and require the external clock
signal provided by a master synchronous device.
FIGURE 15-1:
Full-duplex asynchronous transmit and receive
Two-character input buffer
One-character output buffer
Programmable 8-bit or 9-bit character length
Address detection in 9-bit mode
Input buffer overrun error detection
Received character framing error detection
Half-duplex synchronous master
Half-duplex synchronous slave
Programmable clock and data polarity
The EUSART module implements the following
additional features, making it ideally suited for use in
Local Interconnect Network (LIN) bus systems:
• Automatic detection and calibration of the baud rate
• Wake-up on Break reception
• 13-bit Break character transmit
Block diagrams of the EUSART transmitter and
receiver are shown in Figure 15-1 and Figure 15-2.
EUSART TRANSMIT BLOCK DIAGRAM
Data Bus
TXIE
Interrupt
TXIF
TXREG Register
8
TX/CK pin
MSb
LSb
(8)
0
Pin Buffer
and Control
TRMT
SPEN
• • •
Transmit Shift Register (TSR)
TXEN
Baud Rate Generator
FOSC
TX9
n
BRG16
+1
SPBRGH
÷n
SPBRG
DS40001365F-page 170
Multiplier
x4
x16 x64
SYNC
1 X 0 0
0
BRGH
X 1 1 0
0
BRG16
X 1 0 1
0
TX9D
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 15-2:
EUSART RECEIVE BLOCK DIAGRAM
SPEN
CREN
RX/DT pin
Baud Rate Generator
Data
Recovery
FOSC
BRG16
SPBRGH
SPBRG
Multiplier
x4
x16 x64
SYNC
1 X 0 0
0
BRGH
X 1 1 0
0
BRG16
X 1 0 1
0
Stop
RCIDL
RSR Register
MSb
Pin Buffer
and Control
+1
OERR
(8)
•••
7
1
LSb
0 START
RX9
÷n
n
FERR
RX9D
RCREG Register
8
FIFO
Data Bus
RCIF
RCIE
Interrupt
The operation of the EUSART module is controlled
through three registers:
• Transmit Status and Control (TXSTA)
• Receive Status and Control (RCSTA)
• Baud Rate Control (BAUDCTL)
These registers are detailed in Register 15-1,
Register 15-2 and Register 15-3, respectively.
For all modes of EUSART operation, the TRIS control
bits corresponding to the RX/DT and TX/CK pins should
be set to ‘1’. The EUSART control will automatically
reconfigure the pin from input to output, as needed.
2009-2016 Microchip Technology Inc.
DS40001365F-page 171
PIC18(L)F1XK22
15.1
EUSART Asynchronous Mode
The EUSART transmits and receives data using the
standard non-return-to-zero (NRZ) format. NRZ is
implemented with two levels: a VOH Mark state which
represents a ‘1’ data bit, and a VOL Space state which
represents a ‘0’ data bit. NRZ refers to the fact that
consecutively transmitted data bits of the same value
stay at the output level of that bit without returning to a
neutral level between each bit transmission. An NRZ
transmission port idles in the Mark state. Each character
transmission consists of one Start bit followed by eight
or nine data bits and is always terminated by one or
more Stop bits. The Start bit is always a space and the
Stop bits are always marks. The most common data
format is 8 bits. Each transmitted bit persists for a period
of 1/(Baud Rate). An on-chip dedicated 8-bit/16-bit Baud
Rate Generator is used to derive standard baud rate
frequencies from the system oscillator. See Table 15-5
for examples of baud rate configurations.
The EUSART transmits and receives the LSb first. The
EUSART’s transmitter and receiver are functionally
independent, but share the same data format and baud
rate. Parity is not supported by the hardware, but can
be implemented in software and stored as the ninth
data bit.
15.1.1
EUSART ASYNCHRONOUS
TRANSMITTER
The EUSART transmitter block diagram is shown in
Figure 15-1. The heart of the transmitter is the serial
Transmit Shift Register (TSR), which is not directly
accessible by software. The TSR obtains its data from
the transmit buffer, which is the TXREG register.
15.1.1.1
Enabling the Transmitter
The EUSART transmitter is enabled for asynchronous
operations by configuring the following three control
bits:
• TXEN = 1
• SYNC = 0
• SPEN = 1
All other EUSART control bits are assumed to be in
their default state.
Setting the TXEN bit of the TXSTA register enables the
transmitter circuitry of the EUSART. Clearing the SYNC
bit of the TXSTA register configures the EUSART for
asynchronous operation. Setting the SPEN bit of the
RCSTA register enables the EUSART and automatically
configures the TX/CK I/O pin as an output. If the TX/CK
pin is shared with an analog peripheral the analog I/O
function must be disabled by clearing the corresponding
ANSEL bit.
Note 1: When the SPEN bit is set the RX/DT I/O
pin is automatically configured as an input,
regardless of the state of the
corresponding TRIS bit and whether or not
the EUSART receiver is enabled. The
RX/DT pin data can be read via a normal
PORT read but PORT latch data output is
precluded.
2: The TXIF transmitter interrupt flag is set
when the TXEN enable bit is set.
15.1.1.2
Transmitting Data
A transmission is initiated by writing a character to the
TXREG register. If this is the first character, or the
previous character has been completely flushed from
the TSR, the data in the TXREG is immediately
transferred to the TSR register. If the TSR still contains
all or part of a previous character, the new character
data is held in the TXREG until the Stop bit of the
previous character has been transmitted. The pending
character in the TXREG is then transferred to the TSR
in one TCY immediately following the Stop bit
transmission. The transmission of the Start bit, data bits
and Stop bit sequence commences immediately
following the transfer of the data to the TSR from the
TXREG.
15.1.1.3
Transmit Data Polarity
The polarity of the transmit data can be controlled with
the CKTXP bit of the BAUDCON register. The default
state of this bit is ‘0’ which selects high true transmit
idle and data bits. Setting the CKTXP bit to ‘1’ will invert
the transmit data resulting in low true idle and data bits.
The CKTXP bit controls transmit data polarity only in
Asynchronous mode. In Synchronous mode the
CKTXP bit has a different function.
15.1.1.4
Transmit Interrupt Flag
The TXIF interrupt flag bit of the PIR1 register is set
whenever the EUSART transmitter is enabled and no
character is being held for transmission in the TXREG.
In other words, the TXIF bit is only clear when the TSR
is busy with a character and a new character has been
queued for transmission in the TXREG. The TXIF flag bit
is not cleared immediately upon writing TXREG. TXIF
becomes valid in the second instruction cycle following
the write execution. Polling TXIF immediately following
the TXREG write will return invalid results. The TXIF bit
is read-only, it cannot be set or cleared by software.
The TXIF interrupt can be enabled by setting the TXIE
interrupt enable bit of the PIE1 register. However, the
TXIF flag bit will be set whenever the TXREG is empty,
regardless of the state of TXIE enable bit.
To use interrupts when transmitting data, set the TXIE
bit only when there is more data to send. Clear the
TXIE interrupt enable bit upon writing the last character
of the transmission to the TXREG.
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PIC18(L)F1XK22
15.1.1.5
TSR Status
15.1.1.7
The TRMT bit of the TXSTA register indicates the
status of the TSR register. This is a read-only bit. The
TRMT bit is set when the TSR register is empty and is
cleared when a character is transferred to the TSR
register from the TXREG. The TRMT bit remains clear
until all bits have been shifted out of the TSR register.
No interrupt logic is tied to this bit, so the user needs to
poll this bit to determine the TSR status.
1.
2.
3.
The TSR register is not mapped in data
memory, so it is not available to the user.
Note:
15.1.1.6
4.
Transmitting 9-Bit Characters
The EUSART supports 9-bit character transmissions.
When the TX9 bit of the TXSTA register is set, the
EUSART will shift 9 bits out for each character
transmitted. The TX9D bit of the TXSTA register is the
ninth, and Most Significant, data bit. When transmitting
9-bit data, the TX9D data bit must be written before
writing the 8 Least Significant bits into the TXREG. All
nine bits of data will be transferred to the TSR shift
register immediately after the TXREG is written.
5.
A special 9-bit Address mode is available for use with
multiple receivers. See Section 15.1.2.8 “Address
Detection” for more information on the Address mode.
8.
FIGURE 15-3:
Write to TXREG
BRG Output
(Shift Clock)
RB7/TX/CK
pin
TXIF bit
(Transmit Buffer
Reg. Empty Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
6.
7.
Asynchronous Transmission Set-up
Initialize the SPBRGH:SPBRG register pair and
the BRGH and BRG16 bits to achieve the desired
baud rate (see Section 15.3 “EUSART Baud
Rate Generator (BRG)”).
Enable the asynchronous serial port by clearing
the SYNC bit and setting the SPEN bit.
If 9-bit transmission is desired, set the TX9
control bit. A set ninth data bit will indicate that
the 8 Least Significant data bits are an address
when the receiver is set for address detection.
Set the CKTXP control bit if inverted transmit
data polarity is desired.
Enable the transmission by setting the TXEN
control bit. This will cause the TXIF interrupt bit
to be set.
If interrupts are desired, set the TXIE interrupt
enable bit. An interrupt will occur immediately
provided that the GIE and PEIE bits of the
INTCON register are also set.
If 9-bit transmission is selected, the ninth bit
should be loaded into the TX9D data bit.
Load 8-bit data into the TXREG register. This
will start the transmission.
ASYNCHRONOUS TRANSMISSION
Word 1
Start bit
bit 0
bit 1
bit 7/8
Stop bit
Word 1
1 TCY
Word 1
Transmit Shift Reg
2009-2016 Microchip Technology Inc.
DS40001365F-page 173
PIC18(L)F1XK22
FIGURE 15-4:
ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)
Write to TXREG
Word 1
BRG Output
(Shift Clock)
RB7/TX/CK
pin
Start bit
bit 1
Word 1
bit 7/8
Stop bit
Start bit
bit 0
Word 2
1 TCY
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Word 1
Transmit Shift Reg
Word 2
Transmit Shift Reg
This timing diagram shows two consecutive transmissions.
TABLE 15-1:
Name
bit 0
1 TCY
TXIF bit
(Interrupt Reg. Flag)
Note:
Word 2
REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Bit 7
Bit 6
BAUDCON
ABDOVF
RCIDL
INTCON
GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
DTRXP
CKTXP
BRG16
—
WUE
ABDEN
247
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
247
PIR1
RCSTA
SPBRG
EUSART Baud Rate Generator Register, Low Byte
247
SPBRGH
EUSART Baud Rate Generator Register, High Byte
247
TXREG
EUSART Transmit Register
TXSTA
CSRC
TX9
TXEN
247
SYNC
SENDB
BRGH
TRMT
TX9D
247
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.
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2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
15.1.2
EUSART ASYNCHRONOUS
RECEIVER
The Asynchronous mode would typically be used in
RS-232 systems. The receiver block diagram is shown
in Figure 15-2. The data is received on the RX/DT pin
and drives the data recovery block. The data recovery
block is actually a high-speed shifter operating at 16
times the baud rate, whereas the serial Receive Shift
Register (RSR) operates at the bit rate. When all 8 or 9
bits of the character have been shifted in, they are
immediately transferred to a two character
First-In-First-Out (FIFO) memory. The FIFO buffering
allows reception of two complete characters and the
start of a third character before software must start
servicing the EUSART receiver. The FIFO and RSR
registers are not directly accessible by software.
Access to the received data is via the RCREG register.
15.1.2.1
Enabling the Receiver
The EUSART receiver is enabled for asynchronous
operation by configuring the following three control bits:
• CREN = 1
• SYNC = 0
• SPEN = 1
All other EUSART control bits are assumed to be in
their default state.
Setting the CREN bit of the RCSTA register enables the
receiver circuitry of the EUSART. Clearing the SYNC bit
of the TXSTA register configures the EUSART for
asynchronous operation. Setting the SPEN bit of the
RCSTA register enables the EUSART. The RX/DT I/O
pin must be configured as an input by setting the
corresponding TRIS control bit. If the RX/DT pin is
shared with an analog peripheral the analog I/O function
must be disabled by clearing the corresponding ANSEL
bit.
Note:
When the SPEN bit is set the TX/CK I/O
pin is automatically configured as an
output, regardless of the state of the
corresponding TRIS bit and whether or
not the EUSART transmitter is enabled.
The PORT latch is disconnected from the
output driver so it is not possible to use the
TX/CK pin as a general purpose output.
2009-2016 Microchip Technology Inc.
15.1.2.2
Receiving Data
The receiver data recovery circuit initiates character
reception on the falling edge of the first bit. The first bit,
also known as the Start bit, is always a zero. The data
recovery circuit counts one-half bit time to the center of
the Start bit and verifies that the bit is still a zero. If it is
not a zero then the data recovery circuit aborts
character reception, without generating an error, and
resumes looking for the falling edge of the Start bit. If
the Start bit zero verification succeeds then the data
recovery circuit counts a full bit time to the center of the
next bit. The bit is then sampled by a majority detect
circuit and the resulting ‘0’ or ‘1’ is shifted into the RSR.
This repeats until all data bits have been sampled and
shifted into the RSR. One final bit time is measured and
the level sampled. This is the Stop bit, which is always
a ‘1’. If the data recovery circuit samples a ‘0’ in the
Stop bit position then a framing error is set for this
character, otherwise the framing error is cleared for this
character. See Section 15.1.2.5 “Receive Framing
Error” for more information on framing errors.
Immediately after all data bits and the Stop bit have
been received, the character in the RSR is transferred
to the EUSART receive FIFO and the RCIF interrupt
flag bit of the PIR1 register is set. The top character in
the FIFO is transferred out of the FIFO by reading the
RCREG register.
Note:
15.1.2.3
If the receive FIFO is overrun, no additional
characters will be received until the overrun
condition is cleared. See Section 15.1.2.6
“Receive Overrun Error” for more
information on overrun errors.
Receive Data Polarity
The polarity of the receive data can be controlled with
the DTRXP bit of the BAUDCON register. The default
state of this bit is ‘0’ which selects high true receive idle
and data bits. Setting the DTRXP bit to ‘1’ will invert the
receive data resulting in low true idle and data bits. The
DTRXP bit controls receive data polarity only in
Asynchronous mode. In Synchronous mode the
DTRXP bit has a different function.
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PIC18(L)F1XK22
15.1.2.4
Receive Interrupts
The RCIF interrupt flag bit of the PIR1 register is set
whenever the EUSART receiver is enabled and there is
an unread character in the receive FIFO. The RCIF
interrupt flag bit is read-only, it cannot be set or cleared
by software.
RCIF interrupts are enabled by setting the following
bits:
• RCIE interrupt enable bit of the PIE1 register
• PEIE peripheral interrupt enable bit of the
INTCON register
• GIE global interrupt enable bit of the INTCON
register
The RCIF interrupt flag bit will be set when there is an
unread character in the FIFO, regardless of the state of
interrupt enable bits.
15.1.2.5
Receive Framing Error
Each character in the receive FIFO buffer has a
corresponding framing error Status bit. A framing error
indicates that a Stop bit was not seen at the expected
time. The framing error status is accessed via the
FERR bit of the RCSTA register. The FERR bit
represents the status of the top unread character in the
receive FIFO. Therefore, the FERR bit must be read
before reading the RCREG.
The FERR bit is read-only and only applies to the top
unread character in the receive FIFO. A framing error
(FERR = 1) does not preclude reception of additional
characters. It is not necessary to clear the FERR bit.
Reading the next character from the FIFO buffer will
advance the FIFO to the next character and the next
corresponding framing error.
15.1.2.7
Receiving 9-bit Characters
The EUSART supports 9-bit character reception. When
the RX9 bit of the RCSTA register is set, the EUSART
will shift nine bits into the RSR for each character
received. The RX9D bit of the RCSTA register is the
ninth and Most Significant data bit of the top unread
character in the receive FIFO. When reading 9-bit data
from the receive FIFO buffer, the RX9D data bit must
be read before reading the eight Least Significant bits
from the RCREG.
15.1.2.8
Address Detection
A special Address Detection mode is available for use
when multiple receivers share the same transmission
line, such as in RS-485 systems. Address detection is
enabled by setting the ADDEN bit of the RCSTA
register.
Address detection requires 9-bit character reception.
When address detection is enabled, only characters
with the ninth data bit set will be transferred to the
receive FIFO buffer, thereby setting the RCIF interrupt
bit. All other characters will be ignored.
Upon receiving an address character, user software
determines if the address matches its own. Upon
address match, user software must disable address
detection by clearing the ADDEN bit before the next
Stop bit occurs. When user software detects the end of
the message, determined by the message protocol
used, software places the receiver back into the
Address Detection mode by setting the ADDEN bit.
The FERR bit can be forced clear by clearing the SPEN
bit of the RCSTA register which resets the EUSART.
Clearing the CREN bit of the RCSTA register does not
affect the FERR bit. A framing error by itself does not
generate an interrupt.
Note:
15.1.2.6
If all receive characters in the receive
FIFO have framing errors, repeated reads
of the RCREG will not clear the FERR bit.
Receive Overrun Error
The receive FIFO buffer can hold two characters. An
overrun error will be generated If a third character, in its
entirety, is received before the FIFO is accessed. When
this happens the OERR bit of the RCSTA register is set.
The characters already in the FIFO buffer can be read
but no additional characters will be received until the
error is cleared. The error must be cleared by either
clearing the CREN bit of the RCSTA register or by
resetting the EUSART by clearing the SPEN bit of the
RCSTA register.
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PIC18(L)F1XK22
15.1.2.9
Asynchronous Reception Set-up
15.1.2.10
1.
Initialize the SPBRGH:SPBRG register pair and
the BRGH and BRG16 bits to achieve the
desired baud rate (see Section 15.3 “EUSART
Baud Rate Generator (BRG)”).
2. Enable the serial port by setting the SPEN bit
and the RX/DT pin TRIS bit. The SYNC bit must
be clear for asynchronous operation.
3. If interrupts are desired, set the RCIE interrupt
enable bit and set the GIE and PEIE bits of the
INTCON register.
4. If 9-bit reception is desired, set the RX9 bit.
5. Set the DTRXP if inverted receive polarity is
desired.
6. Enable reception by setting the CREN bit.
7. The RCIF interrupt flag bit will be set when a
character is transferred from the RSR to the
receive buffer. An interrupt will be generated if
the RCIE interrupt enable bit was also set.
8. Read the RCSTA register to get the error flags
and, if 9-bit data reception is enabled, the ninth
data bit.
9. Get the received 8 Least Significant data bits
from the receive buffer by reading the RCREG
register.
10. If an overrun occurred, clear the OERR flag by
clearing the CREN receiver enable bit.
FIGURE 15-5:
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 register pair and
the BRGH and BRG16 bits to achieve the
desired baud rate (see Section 15.3 “EUSART
Baud Rate Generator (BRG)”).
2. Enable the serial port by setting the SPEN bit.
The SYNC bit must be clear for asynchronous
operation.
3. If interrupts are desired, set the RCIE interrupt
enable bit and set the GIE and PEIE bits of the
INTCON register.
4. Enable 9-bit reception by setting the RX9 bit.
5. Enable address detection by setting the ADDEN
bit.
6. Set the DTRXP if inverted receive polarity is
desired.
7. Enable reception by setting the CREN bit.
8. The RCIF interrupt flag bit will be set when a
character with the ninth bit set is transferred
from the RSR to the receive buffer. An interrupt
will be generated if the RCIE interrupt enable bit
was also set.
9. Read the RCSTA register to get the error flags.
The ninth data bit will always be set.
10. Get the received 8 Least Significant data bits
from the receive buffer by reading the RCREG
register. Software determines if this is the
device’s address.
11. If an overrun occurred, clear the OERR flag by
clearing the CREN receiver enable bit.
12. If the device has been addressed, clear the
ADDEN bit to allow all received data into the
receive buffer and generate interrupts.
ASYNCHRONOUS RECEPTION
Start
bit
bit 0
RX/DT pin
9-bit Address Detection Mode Set-up
bit 1
Rcv Shift
Reg
Rcv Buffer Reg
RCIDL
bit 7/8 Stop
bit
Start
bit
Word 1
RCREG
bit 0
bit 7/8 Stop
bit
Start
bit
bit 7/8 Stop
bit
Word 2
RCREG
Read Rcv
Buffer Reg
RCREG
RCIF
(Interrupt Flag)
OERR bit
CREN
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.
2009-2016 Microchip Technology Inc.
DS40001365F-page 177
PIC18(L)F1XK22
TABLE 15-2:
REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
BAUDCON
ABDOVF
RCIDL
DTRXP
CKTXP
BRG16
—
WUE
ABDEN
247
INTCON
GIE/GIEH PEIE/GIEL
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
PIR1
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
CREN
ADDEN
FERR
OERR
RX9D
RCREG
EUSART Receive Register
RCSTA
SPEN
RX9
SREN
247
247
SPBRG
EUSART Baud Rate Generator Register, Low Byte
247
SPBRGH
EUSART Baud Rate Generator Register, High Byte
247
TRISC
TRISC7
TRISC6
TRISC5
TRISC4
TRISC3
TRISC2
TRISC1
TRISC0
248
TXSTA
CSRC
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
247
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.
DS40001365F-page 178
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
15.2
Clock Accuracy with
Asynchronous Operation
The factory calibrates the internal oscillator block
output (HFINTOSC). However, the HFINTOSC
frequency may drift as VDD or temperature changes,
and this directly affects the asynchronous baud rate.
Two methods may be used to adjust the baud rate
clock, but both require a reference clock source of
some kind.
REGISTER 15-1:
The first (preferred) method uses the OSCTUNE
register to adjust the HFINTOSC output. Adjusting the
value in the OSCTUNE register allows for fine resolution
changes to the system clock source. See Section 2.7.1
“OSCTUNE Register” for more information.
The other method adjusts the value in the Baud Rate
Generator. This can be done automatically with the
Auto-Baud Detect feature (see Section 15.3.1
“Auto-Baud Detect”). There may not be fine enough
resolution when adjusting the Baud Rate Generator to
compensate for a gradual change in the peripheral
clock frequency.
TXSTA: TRANSMIT STATUS AND CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R-1
R/W-0
CSRC
TX9
TXEN(1)
SYNC
SENDB
BRGH
TRMT
TX9D
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
CSRC: Clock Source Select bit
Asynchronous mode:
Don’t care
Synchronous mode:
1 = Master mode (clock generated internally from BRG)
0 = Slave mode (clock from external source)
bit 6
TX9: 9-bit Transmit Enable bit
1 = Selects 9-bit transmission
0 = Selects 8-bit transmission
bit 5
TXEN: Transmit Enable bit(1)
1 = Transmit enabled
0 = Transmit disabled
bit 4
SYNC: EUSART Mode Select bit
1 = Synchronous mode
0 = Asynchronous mode
bit 3
SENDB: Send Break Character bit
Asynchronous mode:
1 = Send Sync Break on next transmission (cleared by hardware upon completion)
0 = Sync Break transmission completed
Synchronous mode:
Don’t care
bit 2
BRGH: High Baud Rate Select bit
Asynchronous mode:
1 = High speed
0 = Low speed
Synchronous mode:
Unused in this mode
bit 1
TRMT: Transmit Shift Register Status bit
1 = TSR empty
0 = TSR full
bit 0
TX9D: Ninth bit of Transmit Data
Can be address/data bit or a parity bit.
Note 1:
SREN/CREN overrides TXEN in Sync mode.
2009-2016 Microchip Technology Inc.
DS40001365F-page 179
PIC18(L)F1XK22
REGISTER 15-2:
RCSTA: RECEIVE STATUS AND CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R-0
R-0
R-x
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
SPEN: Serial Port Enable bit
1 = Serial port enabled (configures RX/DT and TX/CK pins as serial port pins)
0 = Serial port disabled (held in Reset)
bit 6
RX9: 9-bit Receive Enable bit
1 = Selects 9-bit reception
0 = Selects 8-bit reception
bit 5
SREN: Single Receive Enable bit
Asynchronous mode:
Don’t care
Synchronous mode – Master:
1 = Enables single receive
0 = Disables single receive
This bit is cleared after reception is complete.
Synchronous mode – Slave
Don’t care
bit 4
CREN: Continuous Receive Enable bit
Asynchronous mode:
1 = Enables receiver
0 = Disables receiver
Synchronous mode:
1 = Enables continuous receive until enable bit CREN is cleared (CREN overrides SREN)
0 = Disables continuous receive
bit 3
ADDEN: Address Detect Enable bit
Asynchronous mode 9-bit (RX9 = 1):
1 = Enables address detection, enable interrupt and load the receive buffer when RSR is set
0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit
Asynchronous mode 8-bit (RX9 = 0):
Don’t care
bit 2
FERR: Framing Error bit
1 = Framing error (can be updated by reading RCREG register and receive next valid byte)
0 = No framing error
bit 1
OERR: Overrun Error bit
1 = Overrun error (can be cleared by clearing bit CREN)
0 = No overrun error
bit 0
RX9D: Ninth bit of Received Data
This can be address/data bit or a parity bit and must be calculated by user firmware.
DS40001365F-page 180
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 15-3:
BAUDCON: BAUD RATE CONTROL REGISTER
R-0
R-1
R/W-0
R/W-0
R/W-0
U-0
R/W-0
R/W-0
ABDOVF
RCIDL
DTRXP
CKTXP
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 Detect Overflow bit
Asynchronous mode:
1 = Auto-baud timer overflowed
0 = Auto-baud timer did not overflow
Synchronous mode:
Don’t care
bit 6
RCIDL: Receive Idle Flag bit
Asynchronous mode:
1 = Receiver is Idle
0 = Start bit has been detected and the receiver is active
Synchronous mode:
Don’t care
bit 5
DTRXP: Data/Receive Polarity Select bit
Asynchronous mode:
1 = Receive data (RX) is inverted (active-low)
0 = Receive data (RX) is not inverted (active-high)
Synchronous mode:
1 = Data (DT) is inverted (active-low)
0 = Data (DT) is not inverted (active-high)
bit 4
CKTXP: Clock/Transmit Polarity Select bit
Asynchronous mode:
1 = Idle state for transmit (TX) is low
0 = Idle state for transmit (TX) is high
Synchronous mode:
1 = Data changes on the falling edge of the clock and is sampled on the rising edge of the clock
0 = Data changes on the rising edge of the clock and is sampled on the falling edge of the clock
bit 3
BRG16: 16-bit Baud Rate Generator bit
1 = 16-bit Baud Rate Generator is used (SPBRGH:SPBRG)
0 = 8-bit Baud Rate Generator is used (SPBRG)
bit 2
Unimplemented: Read as ‘0’
bit 1
WUE: Wake-up Enable bit
Asynchronous mode:
1 = Receiver is waiting for a falling edge. No character will be received but RCIF will be set on the falling
edge. WUE will automatically clear on the rising edge.
0 = Receiver is operating normally
Synchronous mode:
Don’t care
bit 0
ABDEN: Auto-Baud Detect Enable bit
Asynchronous mode:
1 = Auto-Baud Detect mode is enabled (clears when auto-baud is complete)
0 = Auto-Baud Detect mode is disabled
Synchronous mode:
Don’t care
2009-2016 Microchip Technology Inc.
DS40001365F-page 181
PIC18(L)F1XK22
15.3
EUSART Baud Rate Generator
(BRG)
The Baud Rate Generator (BRG) is an 8-bit or 16-bit
timer that is dedicated to the support of both the
asynchronous and synchronous EUSART operation.
By default, the BRG operates in 8-bit mode. Setting the
BRG16 bit of the BAUDCON register selects 16-bit
mode.
If the system clock is changed during an active receive
operation, a receive error or data loss may result. To
avoid this problem, check the status of the RCIDL bit to
make sure that the receive operation is Idle before
changing the system clock.
EXAMPLE 15-1:
For a device with FOSC of 16 MHz, desired baud rate
of 9600, Asynchronous mode, 8-bit BRG:
The SPBRGH:SPBRG register pair determines the
period of the free running baud rate timer. In
Asynchronous mode the multiplier of the baud rate
period is determined by both the BRGH bit of the TXSTA
register and the BRG16 bit of the BAUDCON register. In
Synchronous mode, the BRGH bit is ignored.
F OS C
Desired Baud Rate = --------------------------------------------------------------------64 [SPBRGH:SPBRG] + 1
Solving for SPBRGH:SPBRG:
Table 15-3 contains the formulas for determining the
baud rate. Example 15-1 provides a sample calculation
for determining the baud rate and baud rate error.
Typical baud rates and error values for various
asynchronous modes have been computed for your
convenience and are shown in Table 15-5. It may be
advantageous to use the high baud rate (BRGH = 1),
or the 16-bit BRG (BRG16 = 1) to reduce the baud rate
error. The 16-bit BRG mode is used to achieve slow
baud rates for fast oscillator frequencies.
X=
(
FOSC
-1
64* (Desired Baud Rate)
=
(
16,000,000
64* 9600
)
)-1
= 25.042 = 25
16000000
Calculated Baud Rate = --------------------------64 25 + 1
= 9615
Writing a new value to the SPBRGH, SPBRG register
pair causes the BRG timer to be reset (or cleared). This
ensures that the BRG does not wait for a timer overflow
before outputting the new baud rate.
TABLE 15-3:
CALCULATING BAUD
RATE ERROR
Calc. Baud Rate – Desired Baud Rate
Error = -------------------------------------------------------------------------------------------Desired Baud Rate
9615 – 9600
= ---------------------------------- = 0.16%
9600
BAUD RATE FORMULAS
Configuration Bits
BRG/EUSART Mode
Baud Rate Formula
0
8-bit/Asynchronous
FOSC/[64 (n+1)]
0
1
8-bit/Asynchronous
0
1
0
16-bit/Asynchronous
0
1
1
16-bit/Asynchronous
1
0
x
8-bit/Synchronous
1
x
16-bit/Synchronous
SYNC
BRG16
BRGH
0
0
0
1
Legend:
REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR
Bit 7
BAUDCON ABDOVF
RCSTA
FOSC/[4 (n+1)]
x = Don’t care, n = value of SPBRGH, SPBRG register pair
TABLE 15-4:
Name
FOSC/[16 (n+1)]
SPEN
Bit 6
Bit 5
Bit 4
Bit 3
RCIDL
DTRXP
CKTXP
BRG16
RX9
SREN
CREN
ADDEN
Bit 1
Bit 0
Reset Values
on page
—
WUE
ABDEN
247
FERR
OERR
RX9D
247
Bit 2
SPBRG
EUSART Baud Rate Generator Register, Low Byte
247
SPBRGH
EUSART Baud Rate Generator Register, High Byte
247
TXSTA
CSRC
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
247
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the BRG.
DS40001365F-page 182
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 15-5:
BAUD RATES FOR ASYNCHRONOUS MODES
SYNC = 0, BRGH = 0, BRG16 = 0
BAUD
RATE
FOSC = 48.000 MHz
FOSC = 18.432 MHz
FOSC = 12.000 MHz
FOSC = 11.0592 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
300
—
—
—
—
—
—
—
—
—
—
—
—
1200
—
—
—
1200
0.00
239
1202
0.16
155
1200
0.00
143
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
2400
—
—
—
2400
0.00
119
2404
0.16
77
2400
0.00
71
9600
9615
0.16
77
9600
0.00
29
9375
-2.34
19
9600
0.00
17
10417
10417
0.00
71
10286
-1.26
27
10417
0.00
17
10165
-2.42
16
19.2k
19.23k
0.16
38
19.20k
0.00
14
18.75k
-2.34
9
19.20k
0.00
8
57.6k
57.69k
0.16
12
57.60k
0.00
7
—
—
—
57.60k
0.00
2
115.2k
—
—
—
—
—
—
—
—
—
—
—
—
SYNC = 0, BRGH = 0, BRG16 = 0
BAUD
RATE
FOSC = 8.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
FOSC = 4.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
FOSC = 3.6864 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
FOSC = 1.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
300
—
—
—
300
0.16
207
300
0.00
191
300
0.16
51
1200
1202
0.16
103
1202
0.16
51
1200
0.00
47
1202
0.16
12
2400
2404
0.16
51
2404
0.16
25
2400
0.00
23
—
—
—
9600
9615
0.16
12
—
—
—
9600
0.00
5
—
—
—
10417
10417
0.00
11
10417
0.00
5
—
—
—
—
—
—
19.2k
—
—
—
—
—
—
19.20k
0.00
2
—
—
—
57.6k
—
—
—
—
—
—
57.60k
0.00
0
—
—
—
115.2k
—
—
—
—
—
—
—
—
—
—
—
—
SYNC = 0, BRGH = 1, BRG16 = 0
BAUD
RATE
FOSC = 48.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
FOSC = 18.432 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
FOSC = 12.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
FOSC = 11.0592 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
300
—
—
—
—
—
—
—
—
—
—
—
—
1200
—
—
—
—
—
—
—
—
—
—
—
—
2400
—
—
—
—
—
—
—
—
—
—
—
—
9600
—
—
—
9600
0.00
119
9615
0.16
77
9600
0.00
71
10417
—
—
—
10378
-0.37
110
10417
0.00
71
10473
0.53
65
19.2k
19.23k
0.16
155
19.20k
0.00
59
19.23k
0.16
38
19.20k
0.00
35
57.6k
57.69k
0.16
51
57.60k
0.00
19
57.69k
0.16
12
57.60k
0.00
11
115.2k
115.38k
0.16
25
115.2k
0.00
9
—
—
—
115.2k
0.00
5
2009-2016 Microchip Technology Inc.
DS40001365F-page 183
PIC18(L)F1XK22
TABLE 15-5:
BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)
SYNC = 0, BRGH = 1, BRG16 = 0
BAUD
RATE
FOSC = 8.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
FOSC = 4.000 MHz
Actual
Rate
%
Error
SPBRG
value
(decimal)
FOSC = 3.6864 MHz
Actual
Rate
FOSC = 1.000 MHz
%
Error
SPBRG
value
(decimal)
Actual
Rate
%
Error
SPBRG
value
(decimal)
300
1200
—
—
—
—
—
—
—
1202
—
0.16
—
207
—
1200
—
0.00
—
191
300
1202
0.16
0.16
207
51
2400
2404
0.16
207
2404
0.16
103
2400
0.00
95
2404
0.16
25
—
9600
9615
0.16
51
9615
0.16
25
9600
0.00
23
—
—
10417
10417
0.00
47
10417
0.00
23
10473
0.53
21
10417
0.00
5
19.2k
19231
0.16
25
19.23k
0.16
12
19.2k
0.00
11
—
—
—
57.6k
55556
-3.55
8
—
—
—
57.60k
0.00
3
—
—
—
115.2k
—
—
—
—
—
—
115.2k
0.00
1
—
—
—
SYNC = 0, BRGH = 0, BRG16 = 1
BAUD
RATE
FOSC = 48.000 MHz
Actual
Rate
%
Error
FOSC = 18.432 MHz
SPBRGH
:SPBRG
(decimal)
Actual
Rate
%
Error
SPBRGH
:SPBRG
(decimal)
FOSC = 12.000 MHz
Actual
Rate
FOSC = 11.0592 MHz
%
Error
SPBRGH
:SPBRG
(decimal)
Actual
Rate
%
Error
SPBRGH
:SPBRG
(decimal)
300
300.0
0.00
9999
300.0
0.00
3839
300
0.00
2499
300.0
0.00
2303
1200
1200.1
0.00
2499
1200
0.00
959
1200
0.00
624
1200
0.00
575
2400
2400
0.00
1249
2400
0.00
479
2404
0.16
311
2400
0.00
287
71
9600
9615
0.16
311
9600
0.00
119
9615
0.16
77
9600
0.00
10417
10417
0.00
287
10378
-0.37
110
10417
0.00
71
10473
0.53
65
19.2k
19.23k
0.16
155
19.20k
0.00
59
19.23k
0.16
38
19.20k
0.00
35
57.6k
57.69k
0.16
51
57.60k
0.00
19
57.69k
0.16
12
57.60k
0.00
11
115.2k
115.38k
0.16
25
115.2k
0.00
9
—
—
—
115.2k
0.00
5
SYNC = 0, BRGH = 0, BRG16 = 1
BAUD
RATE
FOSC = 8.000 MHz
Actual
Rate
%
Error
SPBRGH
:SPBRG
(decimal)
FOSC = 4.000 MHz
Actual
Rate
FOSC = 3.6864 MHz
%
Error
SPBRGH
:SPBRG
(decimal)
Actual
Rate
FOSC = 1.000 MHz
%
Error
SPBRGH
:SPBRG
(decimal)
Actual
Rate
%
Error
SPBRGH
:SPBRG
(decimal)
300
299.9
-0.02
1666
300.1
0.04
832
300.0
0.00
767
300.5
0.16
207
1200
1199
-0.08
416
1202
0.16
207
1200
0.00
191
1202
0.16
51
2400
2404
0.16
207
2404
0.16
103
2400
0.00
95
2404
0.16
25
9600
9615
0.16
51
9615
0.16
25
9600
0.00
23
—
—
—
10417
10417
0.00
47
10417
0.00
23
10473
0.53
21
10417
0.00
5
19.2k
19.23k
0.16
25
19.23k
0.16
12
19.20k
0.00
11
—
—
—
57.6k
55556
-3.55
8
—
—
—
57.60k
0.00
3
—
—
—
115.2k
—
—
—
—
—
—
115.2k
0.00
1
—
—
—
DS40001365F-page 184
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 15-5:
BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
BAUD
RATE
FOSC = 48.000 MHz
FOSC = 18.432 MHz
FOSC = 12.000 MHz
FOSC = 11.0592 MHz
Actual
Rate
%
Error
SPBRGH
:SPBRG
(decimal)
300
1200
300
1200
0.00
0.00
39999
9999
300.0
1200
0.00
0.00
15359
3839
300
1200
0.00
0.00
9999
2499
300.0
1200
0.00
0.00
9215
2303
2400
2400
0.00
4999
2400
0.00
1919
2400
0.00
1249
2400
0.00
1151
Actual
Rate
%
Error
SPBRGH
:SPBRG
(decimal)
Actual
Rate
%
Error
SPBRGH
:SPBRG
(decimal)
Actual
Rate
%
Error
SPBRGH
:SPBRG
(decimal)
9600
9600
0.00
1249
9600
0.00
479
9615
0.16
311
9600
0.00
287
10417
10417
0.00
1151
10425
0.08
441
10417
0.00
287
10433
0.16
264
19.2k
19.20k
0.00
624
19.20k
0.00
239
19.23k
0.16
155
19.20k
0.00
143
57.6k
57.69k
0.16
207
57.60k
0.00
79
57.69k
0.16
51
57.60k
0.00
47
115.2k
115.38k
0.16
103
115.2k
0.00
39
115.38k
0.16
25
115.2k
0.00
23
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
BAUD
RATE
FOSC = 8.000 MHz
Actual
Rate
FOSC = 4.000 MHz
%
Error
SPBRGH
:SPBRG
(decimal)
Actual
Rate
FOSC = 3.6864 MHz
%
Error
SPBRGH
:SPBRG
(decimal)
Actual
Rate
FOSC = 1.000 MHz
%
Error
SPBRGH
:SPBRG
(decimal)
Actual
Rate
%
Error
SPBRGH
:SPBRG
(decimal)
832
300
300.0
0.00
6666
300.0
0.01
3332
300.0
0.00
3071
300.1
0.04
1200
1200
-0.02
1666
1200
0.04
832
1200
0.00
767
1202
0.16
207
2400
2401
0.04
832
2398
0.08
416
2400
0.00
383
2404
0.16
103
9600
9615
0.16
207
9615
0.16
103
9600
0.00
95
9615
0.16
25
10417
10417
0.00
191
10417
0.00
95
10473
0.53
87
10417
0.00
23
19.2k
19.23k
0.16
103
19.23k
0.16
51
19.20k
0.00
47
19.23k
0.16
12
57.6k
57.14k
-0.79
34
58.82k
2.12
16
57.60k
0.00
15
—
—
—
115.2k
117.6k
2.12
16
111.1k
-3.55
8
115.2k
0.00
7
—
—
—
2009-2016 Microchip Technology Inc.
DS40001365F-page 185
PIC18(L)F1XK22
15.3.1
AUTO-BAUD DETECT
The EUSART module supports automatic detection
and calibration of the baud rate.
In the Auto-Baud Detect (ABD) mode, the clock to the
BRG is reversed. Rather than the BRG clocking the
incoming RX signal, the RX signal is timing the BRG.
The Baud Rate Generator is used to time the period of
a received 55h (ASCII “U”), which is the Sync character
for the LIN bus. The unique feature of this character is
that it has five rising edges including the Stop bit edge.
Setting the ABDEN bit of the BAUDCON register starts
the auto-baud calibration sequence (Figure 15-6).
While the ABD sequence takes place, the EUSART
state machine is held in Idle. On the first rising edge of
the receive line, after the Start bit, the SPBRG begins
counting up using the BRG counter clock as shown in
Table 15-6. The fifth rising edge will occur on the RX pin
at the end of the eighth bit period. At that time, an
accumulated value totaling the proper BRG period is
left in the SPBRGH:SPBRG register pair, the ABDEN
bit is automatically cleared, and the RCIF interrupt flag
is set. A read operation on the RCREG needs to be
performed to clear the RCIF interrupt. RCREG content
should be discarded. When calibrating for modes that
do not use the SPBRGH register the user can verify
that the SPBRG register did not overflow by checking
for 00h in the SPBRGH register.
The BRG auto-baud clock is determined by the BRG16
and BRGH bits as shown in Table 15-6. During ABD,
both the SPBRGH and SPBRG registers are used as a
16-bit counter, independent of the BRG16 bit setting.
While calibrating the baud rate period, the SPBRGH
FIGURE 15-6:
Note 1: If the WUE bit is set with the ABDEN bit,
auto-baud detection will occur on the byte
following the Break character (see
Section 15.3.3 “Auto-Wake-up on
Break”).
2: It is up to the user to determine that the
incoming character baud rate is within the
range of the selected BRG clock source.
Some combinations of oscillator frequency
and EUSART baud rates are not possible.
3: During the auto-baud process, the
auto-baud counter starts counting at 1.
Upon completion of the auto-baud
sequence, to achieve maximum accuracy,
subtract 1 from the SPBRGH:SPBRG
register pair.
TABLE 15-6:
BRG COUNTER CLOCK RATES
BRG16
BRGH
BRG Base
Clock
BRG ABD
Clock
0
0
FOSC/64
FOSC/512
0
1
FOSC/16
FOSC/128
1
0
FOSC/16
FOSC/128
1
1
FOSC/4
FOSC/32
Note:
During the ABD sequence, SPBRG and
SPBRGH registers are both used as a 16-bit
counter, independent of BRG16 setting.
AUTOMATIC BAUD RATE CALIBRATION
XXXXh
BRG Value
and SPBRG registers are clocked at 1/8th the BRG
base clock rate. The resulting byte measurement is the
average bit time when clocked at full speed.
RX pin
0000h
001Ch
Start
Edge #1
bit 1
bit 0
Edge #2
bit 3
bit 2
Edge #3
bit 5
bit 4
Edge #4
bit 7
bit 6
Edge #5
Stop bit
BRG Clock
Auto Cleared
Set by User
ABDEN bit
RCIDL
RCIF bit
(Interrupt)
Read
RCREG
SPBRG
XXh
1Ch
SPBRGH
XXh
00h
Note 1:
The ABD sequence requires the EUSART module to be configured in Asynchronous mode.
DS40001365F-page 186
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
15.3.2
AUTO-BAUD OVERFLOW
During the course of automatic baud detection, the
ABDOVF bit of the BAUDCON register will be set if the
baud rate counter overflows before the fifth rising edge
is detected on the RX pin. The ABDOVF bit indicates
that the counter has exceeded the maximum count that
can fit in the 16 bits of the SPBRGH:SPBRG register
pair. After the ABDOVF has been set, the counter
continues to count until the fifth rising edge is detected
on the RX pin. Upon detecting the fifth RX edge, the
hardware will set the RCIF Interrupt Flag and clear the
ABDEN bit of the BAUDCON register. The RCIF flag
can be subsequently cleared by reading the RCREG
register. The ABDOVF flag of the BAUDCON register
can be cleared by software directly.
To terminate the auto-baud process before the RCIF
flag is set, clear the ABDEN bit then clear the ABDOVF
bit of the BAUDCON register. The ABDOVF bit will
remain set if the ABDEN bit is not cleared first.
15.3.3
AUTO-WAKE-UP ON BREAK
During Sleep mode, all clocks to the EUSART are
suspended. Because of this, the Baud Rate Generator
is inactive and a proper character reception cannot be
performed. The Auto-Wake-up feature allows the
controller to wake-up due to activity on the RX/DT line.
This feature is available only in Asynchronous mode.
The Auto-Wake-up feature is enabled by setting the
WUE bit of the BAUDCON register. Once set, the normal
receive sequence on RX/DT is disabled, and the
EUSART remains in an Idle state, monitoring for a
wake-up event independent of the CPU mode. A
wake-up event consists of a high-to-low transition on the
RX/DT line. (This coincides with the start of a Sync Break
or a wake-up signal character for the LIN protocol.)
The EUSART module generates an RCIF interrupt
coincident with the wake-up event. The interrupt is
generated synchronously to the Q clocks in normal CPU
operating modes (Figure 15-7), and asynchronously if
the device is in Sleep mode (Figure 15-8). The interrupt
condition is cleared by reading the RCREG register.
15.3.3.1
Special Considerations
Break Character
To avoid character errors or character fragments during
a wake-up event, the wake-up character must be all
zeros.
When the wake-up is enabled the function works
independent of the low time on the data stream. If the
WUE bit is set and a valid non-zero character is
received, the low time from the Start bit to the first rising
edge will be interpreted as the wake-up event. The
remaining bits in the character will be received as a
fragmented character and subsequent characters can
result in framing or overrun errors.
Therefore, the initial character in the transmission must
be all ‘0’s. This must be 10 or more bit times, 13-bit
times recommended for LIN bus, or any number of bit
times for standard RS-232 devices.
Oscillator Start-up Time
Oscillator start-up time must be considered, especially
in applications using oscillators with longer start-up
intervals (i.e., LP, XT or HS/PLL mode). The Sync
Break (or wake-up signal) character must be of
sufficient length, and be followed by a sufficient
interval, to allow enough time for the selected oscillator
to start and provide proper initialization of the EUSART.
WUE Bit
The wake-up event causes a receive interrupt by
setting the RCIF bit. The WUE bit is cleared by
hardware by a rising edge on RX/DT. The interrupt
condition is then cleared by software by reading the
RCREG register and discarding its contents.
To ensure that no actual data is lost, check the RCIDL
bit to verify that a receive operation is not in process
before setting the WUE bit. If a receive operation is not
occurring, the WUE bit may then be set just prior to
entering the Sleep mode.
The WUE bit is automatically cleared by the low-to-high
transition on the RX line at the end of the Break. This
signals to the user that the Break event is over. At this
point, the EUSART module is in Idle mode waiting to
receive the next character.
2009-2016 Microchip Technology Inc.
DS40001365F-page 187
PIC18(L)F1XK22
FIGURE 15-7:
AUTO-WAKE-UP BIT (WUE) TIMING DURING NORMAL OPERATION
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
Auto Cleared
Bit set by user
WUE bit
RX/DT Line
RCIF
Note 1:
Cleared due to User Read of RCREG
The EUSART remains in Idle while the WUE bit is set.
FIGURE 15-8:
AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP
Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4
Q1
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4
OSC1
Auto Cleared
Bit Set by User
WUE bit
RX/DT Line
Note 1
RCIF
Sleep Command Executed
Note 1:
2:
Sleep Ends
Cleared due to User Read of RCREG
If the wake-up event requires long oscillator warm-up time, the automatic clearing of the WUE bit can occur while the stposc signal is
still active. This sequence should not depend on the presence of Q clocks.
The EUSART remains in Idle while the WUE bit is set.
DS40001365F-page 188
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
15.3.4
BREAK CHARACTER SEQUENCE
The EUSART module has the capability of sending the
special Break character sequences that are required by
the LIN bus standard. A Break character consists of a
Start bit, followed by 12 ‘0’ bits and a Stop bit.
To send a Break character, set the SENDB and TXEN
bits of the TXSTA register. The Break character
transmission is then initiated by a write to the TXREG.
The value of data written to TXREG will be ignored and
all ‘0’s will be transmitted.
The SENDB bit is automatically reset by hardware after
the corresponding Stop bit is sent. This allows the user
to preload the transmit FIFO with the next transmit byte
following the Break character (typically, the Sync
character in the LIN specification).
The TRMT bit of the TXSTA register indicates when the
transmit operation is active or Idle, just as it does during
normal transmission. See Figure 15-9 for the timing of
the Break character sequence.
15.3.4.1
Break and Sync Transmit Sequence
The following sequence will start a message frame
header made up of a Break, followed by an auto-baud
Sync byte. This sequence is typical of a LIN bus
master.
1.
2.
3.
4.
5.
15.3.5
RECEIVING A BREAK CHARACTER
The Enhanced EUSART module can receive a Break
character in two ways.
The first method to detect a Break character uses the
FERR bit of the RCSTA register and the Received data
as indicated by RCREG. The Baud Rate Generator is
assumed to have been initialized to the expected baud
rate.
A Break character has been received when;
• RCIF bit is set
• FERR bit is set
• RCREG = 00h
The second method uses the Auto-Wake-up feature
described in Section 15.3.3 “Auto-Wake-up on
Break”. By enabling this feature, the EUSART will
sample the next two transitions on RX/DT, cause an
RCIF interrupt, and receive the next data byte followed
by another interrupt.
Note that following a Break character, the user will
typically want to enable the Auto-Baud Detect feature.
For both methods, the user can set the ABDEN bit of
the BAUDCON register before placing the EUSART in
Sleep mode.
Configure the EUSART for the desired mode.
Set the TXEN and SENDB bits to enable the
Break sequence.
Load the TXREG with a dummy character to
initiate transmission (the value is ignored).
Write ‘55h’ to TXREG to load the Sync character
into the transmit FIFO buffer.
After the Break has been sent, the SENDB bit is
reset by hardware and the Sync character is
then transmitted.
When the TXREG becomes empty, as indicated by the
TXIF, the next data byte can be written to TXREG.
FIGURE 15-9:
Write to TXREG
SEND BREAK CHARACTER SEQUENCE
Dummy Write
BRG Output
(Shift Clock)
TX (pin)
Start bit
bit 0
bit 1
bit 11
Stop bit
Break
TXIF bit
(Transmit
interrupt Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
SENDB
(send Break
control bit)
2009-2016 Microchip Technology Inc.
SENDB Sampled Here
Auto Cleared
DS40001365F-page 189
PIC18(L)F1XK22
15.4
EUSART Synchronous Mode
Synchronous serial communications are typically used
in systems with a single master and one or more
slaves. The master device contains the necessary
circuitry for baud rate generation and supplies the clock
for all devices in the system. Slave devices can take
advantage of the master clock by eliminating the
internal clock generation circuitry.
There are two signal lines in Synchronous mode: a
bidirectional data line and a clock line. Slaves use the
external clock supplied by the master to shift the serial
data into and out of their respective receive and
transmit shift registers. Since the data line is
bidirectional, synchronous operation is half-duplex
only. Half-duplex refers to the fact that master and
slave devices can receive and transmit data but not
both simultaneously. The EUSART can operate as
either a master or slave device.
Start and Stop bits are not used in synchronous
transmissions.
15.4.1
SYNCHRONOUS MASTER MODE
The following bits are used to configure the EUSART
for synchronous master operation:
•
•
•
•
•
SYNC = 1
CSRC = 1
SREN = 0 (for transmit); SREN = 1 (for receive)
CREN = 0 (for transmit); CREN = 1 (for receive)
SPEN = 1
Setting the SYNC bit of the TXSTA register configures
the device for synchronous operation. Setting the CSRC
bit of the TXSTA register configures the device as a
master. Clearing the SREN and CREN bits of the RCSTA
register ensures that the device is in the Transmit mode,
otherwise the device will be configured to receive. Setting
the SPEN bit of the RCSTA register enables the
EUSART. If the RX/DT or TX/CK pins are shared with an
analog peripheral the analog I/O functions must be
disabled by clearing the corresponding ANSEL bits.
15.4.1.2
Clock Polarity
A clock polarity option is provided for Microwire
compatibility. Clock polarity is selected with the CKTXP
bit of the BAUDCON register. Setting the CKTXP bit
sets the clock Idle state as high. When the CKTXP bit
is set, the data changes on the falling edge of each
clock and is sampled on the rising edge of each clock.
Clearing the CKTXP bit sets the Idle state as low. When
the CKTXP bit is cleared, the data changes on the
rising edge of each clock and is sampled on the falling
edge of each clock.
15.4.1.3
Synchronous Master Transmission
Data is transferred out of the device on the RX/DT pin.
The RX/DT and TX/CK pin output drivers are
automatically enabled when the EUSART is configured
for synchronous master transmit operation.
A transmission is initiated by writing a character to the
TXREG register. If the TSR still contains all or part of a
previous character the new character data is held in the
TXREG until the last bit of the previous character has
been transmitted. If this is the first character, or the
previous character has been completely flushed from
the TSR, the data in the TXREG is immediately
transferred to the TSR. The transmission of the
character commences immediately following the
transfer of the data to the TSR from the TXREG.
Each data bit changes on the leading edge of the
master clock and remains valid until the subsequent
leading clock edge.
Note:
15.4.1.4
The TSR register is not mapped in data
memory, so it is not available to the user.
Data Polarity
The polarity of the transmit and receive data can be
controlled with the DTRXP bit of the BAUDCON
register. The default state of this bit is ‘0’ which selects
high true transmit and receive data. Setting the DTRXP
bit to ‘1’ will invert the data resulting in low true transmit
and receive data.
The TRIS bits corresponding to the RX/DT and TX/CK
pins should be set.
15.4.1.1
Master Clock
Synchronous data transfers use a separate clock line,
which is synchronous with the data. A device configured
as a master transmits the clock on the TX/CK line. The
TX/CK pin output driver is automatically enabled when
the EUSART is configured for synchronous transmit or
receive operation. Serial data bits change on the leading
edge to ensure they are valid at the trailing edge of each
clock. One clock cycle is generated for each data bit.
Only as many clock cycles are generated as there are
data bits.
DS40001365F-page 190
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
15.4.1.5
1.
2.
Synchronous Master Transmission
Set-up
3.
Initialize the SPBRGH, SPBRG register pair and
the BRGH and BRG16 bits to achieve the
desired baud rate (see Section 15.3 “EUSART
Baud Rate Generator (BRG)”).
Enable the synchronous master serial port by
setting bits SYNC, SPEN and CSRC. Set the
TRIS bits corresponding to the RX/DT and
TX/CK I/O pins.
4.
5.
6.
FIGURE 15-10:
7.
8.
Disable Receive mode by clearing bits SREN
and CREN.
Enable Transmit mode by setting the TXEN bit.
If 9-bit transmission is desired, set the TX9 bit.
If interrupts are desired, set the TXIE, GIE and
PEIE interrupt enable bits.
If 9-bit transmission is selected, the ninth bit
should be loaded in the TX9D bit.
Start transmission by loading data to the TXREG
register.
SYNCHRONOUS TRANSMISSION
RX/DT
pin
bit 0
bit 1
Word 1
bit 2
bit 7
bit 0
bit 1
Word 2
bit 7
TX/CK pin
(SCKP = 0)
TX/CK pin
(SCKP = 1)
Write to
TXREG Reg
Write Word 1
Write Word 2
TXIF bit
(Interrupt Flag)
TRMT bit
TXEN bit
Note:
‘1’
‘1’
Sync Master mode, SPBRG = 0, continuous transmission of two 8-bit words.
FIGURE 15-11:
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
RX/DT pin
bit 0
bit 1
bit 2
bit 6
bit 7
TX/CK pin
Write to
TXREG reg
TXIF bit
TRMT bit
TXEN bit
2009-2016 Microchip Technology Inc.
DS40001365F-page 191
PIC18(L)F1XK22
TABLE 15-7:
Name
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
BAUDCON
ABDOVF
RCIDL
DTRXP
CKTXP
BRG16
INTCON
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
RABIE
Bit 1
Bit 0
Reset
Values
on page
—
WUE
ABDEN
247
TMR0IF
INT0IF
RABIF
245
Bit 2
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
247
PIR1
RCSTA
SPBRG
EUSART Baud Rate Generator Register, Low Byte
247
SPBRGH
EUSART Baud Rate Generator Register, High Byte
247
TRISC
TXREG
TXSTA
TRISC7
TRISC6
TRISC5
TRISC4
TRISC3
TRISC2
TRISC1
TRISC0
EUSART Transmit Register
CSRC
TX9
TXEN
248
247
SYNC
SENDB
BRGH
TRMT
TX9D
247
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.
15.4.1.6
Synchronous Master Reception
Data is received at the RX/DT pin. The RX/DT pin
output driver must be disabled by setting the
corresponding TRIS bits when the EUSART is
configured for synchronous master receive operation.
In Synchronous mode, reception is enabled by setting
either the Single Receive Enable bit (SREN of the
RCSTA register) or the Continuous Receive Enable bit
(CREN of the RCSTA register).
When SREN is set and CREN is clear, only as many
clock cycles are generated as there are data bits in a
single character. The SREN bit is automatically cleared
at the completion of one character. When CREN is set,
clocks are continuously generated until CREN is
cleared. If CREN is cleared in the middle of a character
the CK clock stops immediately and the partial
character is discarded. If SREN and CREN are both
set, then SREN is cleared at the completion of the first
character and CREN takes precedence.
To initiate reception, set either SREN or CREN. Data is
sampled at the RX/DT pin on the trailing edge of the
TX/CK clock pin and is shifted into the Receive Shift
Register (RSR). When a complete character is
received into the RSR, the RCIF bit is set and the
character is automatically transferred to the two
character receive FIFO. The Least Significant eight bits
of the top character in the receive FIFO are available in
RCREG. The RCIF bit remains set as long as there are
unread characters in the receive FIFO.
DS40001365F-page 192
15.4.1.7
Slave Clock
Synchronous data transfers use a separate clock line,
which is synchronous with the data. A device configured
as a slave receives the clock on the TX/CK line. The
TX/CK pin output driver must be disabled by setting the
associated TRIS bit when the device is configured for
synchronous slave transmit or receive operation. Serial
data bits change on the leading edge to ensure they are
valid at the trailing edge of each clock. One data bit is
transferred for each clock cycle. Only as many clock
cycles should be received as there are data bits.
15.4.1.8
Receive Overrun Error
The receive FIFO buffer can hold two characters. An
overrun error will be generated if a third character, in its
entirety, is received before RCREG is read to access
the FIFO. When this happens the OERR bit of the
RCSTA register is set. Previous data in the FIFO will
not be overwritten. The two characters in the FIFO
buffer can be read, however, no additional characters
will be received until the error is cleared. The OERR bit
can only be cleared by clearing the overrun condition.
If the overrun error occurred when the SREN bit is set
and CREN is clear then the error is cleared by reading
RCREG. If the overrun occurred when the CREN bit is
set then the error condition is cleared by either clearing
the CREN bit of the RCSTA register or by clearing the
SPEN bit which resets the EUSART.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
15.4.1.9
Receiving 9-bit Characters
3.
4.
Ensure bits CREN and SREN are clear.
If using interrupts, set the GIE and PEIE bits of
the INTCON register and set RCIE.
5. If 9-bit reception is desired, set bit RX9.
6. Start reception by setting the SREN bit or for
continuous reception, set the CREN bit.
7. Interrupt flag bit RCIF will be set when reception
of a character is complete. An interrupt will be
generated if the enable bit RCIE was set.
8. Read the RCSTA register to get the ninth 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 an overrun error occurs, clear the error by
either clearing the CREN bit of the RCSTA
register or by clearing the SPEN bit which resets
the EUSART.
The EUSART supports 9-bit character reception. When
the RX9 bit of the RCSTA register is set the EUSART
will shift 9-bits into the RSR for each character
received. The RX9D bit of the RCSTA register is the
ninth, and Most Significant, data bit of the top unread
character in the receive FIFO. When reading 9-bit data
from the receive FIFO buffer, the RX9D data bit must
be read before reading the eight Least Significant bits
from the RCREG.
15.4.1.10
1.
2.
Synchronous Master Reception
Set-up
Initialize the SPBRGH, SPBRG register pair for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
Enable the synchronous master serial port by
setting bits SYNC, SPEN and CSRC. Disable
RX/DT and TX/CK output drivers by setting the
corresponding TRIS bits.
FIGURE 15-12:
RX/DT
pin
SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
bit 0
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
TX/CK pin
(SCKP = 0)
TX/CK pin
(SCKP = 1)
Write to
bit SREN
SREN bit
CREN bit ‘0’
‘0’
RCIF bit
(Interrupt)
Read
RXREG
Note:
Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRGH = 0.
2009-2016 Microchip Technology Inc.
DS40001365F-page 193
PIC18(L)F1XK22
TABLE 15-8:
Name
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Bit 7
BAUDCON ABDOVF
INTCON
Bit 6
RCIDL
GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
DTRXP
CKTXP
BRG16
—
WUE
ABDEN
247
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
PIR1
RCREG
RCSTA
EUSART Receive Register
SPEN
RX9
SREN
247
CREN
ADDEN
SPBRG
EUSART Baud Rate Generator Register, Low Byte
SPBRGH
EUSART Baud Rate Generator Register, High Byte
TXSTA
CSRC
TX9
TXEN
SYNC
SENDB
FERR
OERR
RX9D
247
247
247
BRGH
TRMT
TX9D
247
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.
DS40001365F-page 194
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
15.4.2
SYNCHRONOUS SLAVE MODE
The following bits are used to configure the EUSART
for synchronous slave operation:
•
•
•
•
•
SYNC = 1
CSRC = 0
SREN = 0 (for transmit); SREN = 1 (for receive)
CREN = 0 (for transmit); CREN = 1 (for receive)
SPEN = 1
1.
2.
3.
4.
Setting the SYNC bit of the TXSTA register configures the
device for synchronous operation. Clearing the CSRC bit
of the TXSTA register configures the device as a slave.
Clearing the SREN and CREN bits of the RCSTA register
ensures that the device is in the Transmit mode,
otherwise the device will be configured to receive. Setting
the SPEN bit of the RCSTA register enables the
EUSART. If the RX/DT or TX/CK pins are shared with an
analog peripheral the analog I/O functions must be
disabled by clearing the corresponding ANSEL bits.
RX/DT and TX/CK pin output drivers must be disabled
by setting the corresponding TRIS bits.
15.4.2.1
If two words are written to the TXREG and then the
SLEEP instruction is executed, the following will occur:
EUSART Synchronous Slave
Transmit
The operation of the Synchronous Master and Slave
modes
are
identical
(see
Section 15.4.1.3
“Synchronous Master Transmission”), except in the
case of the Sleep mode.
5.
15.4.2.2
1.
2.
3.
4.
5.
6.
7.
TABLE 15-9:
The first character will immediately transfer to
the TSR register and transmit.
The second word will remain in TXREG register.
The TXIF bit will not be set.
After the first character has been shifted out of
TSR, the TXREG register will transfer the second
character to the TSR and the TXIF bit will now be
set.
If the PEIE and TXIE bits are set, the interrupt
will wake the device from Sleep and execute the
next instruction. If the GIE bit is also set, the
program will call the Interrupt Service Routine.
Synchronous Slave Transmission
Set-up
Set the SYNC and SPEN bits and clear the
CSRC bit. Set the TRIS bits corresponding to
the RX/DT and TX/CK I/O pins.
Clear the CREN and SREN bits.
If using interrupts, ensure that the GIE and PEIE
bits of the INTCON register are set and set the
TXIE bit.
If 9-bit transmission is desired, set the TX9 bit.
Enable transmission by setting the TXEN bit.
If 9-bit transmission is selected, insert the Most
Significant bit into the TX9D bit.
Start transmission by writing the Least
Significant eight bits to the TXREG register.
REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
BAUDCON
ABDOVF
RCIDL
DTRXP
CKTXP
BRG16
—
WUE
ABDEN
247
INTCON
GIE/GIEH PEIE/GIEL TMR0IE
Name
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
PIR1
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
247
RCSTA
SPBRG
EUSART Baud Rate Generator Register, Low Byte
SPBRGH
EUSART Baud Rate Generator Register, High Byte
TRISC
TXREG
TXSTA
TRISC7
TRISC6
TRISC5
247
247
TRISC4
TRISC3
TRISC2
TRISC1
TRISC0
248
SYNC
SENDB
BRGH
TRMT
TX9D
247
EUSART Transmit Register
CSRC
TX9
TXEN
247
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.
2009-2016 Microchip Technology Inc.
DS40001365F-page 195
PIC18(L)F1XK22
15.4.2.3
EUSART Synchronous Slave
Reception
15.4.2.4
The operation of the Synchronous Master and Slave
modes is identical (Section 15.4.1.6 “Synchronous
Master Reception”), with the following exceptions:
1.
• Sleep
• CREN bit is always set, therefore the receiver is
never Idle
• SREN bit, which is a “don't care” in Slave mode
2.
A character may be received while in Sleep mode by
setting the CREN bit prior to entering Sleep. Once the
word is received, the RSR register will transfer the data
to the RCREG register. If the RCIE enable bit is set, the
interrupt generated will wake the device from Sleep
and execute the next instruction. If the GIE bit is also
set, the program will branch to the interrupt vector.
3.
4.
5.
6.
7.
8.
Synchronous Slave Reception
Set-up
Set the SYNC and SPEN bits and clear the
CSRC bit. Set the TRIS bits corresponding to
the RX/DT and TX/CK I/O pins.
If using interrupts, ensure that the GIE and PEIE
bits of the INTCON register are set and set the
RCIE bit.
If 9-bit reception is desired, set the RX9 bit.
Set the CREN bit to enable reception.
The RCIF bit will be set when reception is
complete. An interrupt will be generated if the
RCIE bit was set.
If 9-bit mode is enabled, retrieve the Most
Significant bit from the RX9D bit of the RCSTA
register.
Retrieve the eight Least Significant bits from the
receive FIFO by reading the RCREG register.
If an overrun error occurs, clear the error by
either clearing the CREN bit of the RCSTA
register or by clearing the SPEN bit which resets
the EUSART.
TABLE 15-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
BAUDCON
ABDOVF
RCIDL
DTRXP
CKTXP
BRG16
—
WUE
ABDEN
247
INTCON
GIE/GIEH PEIE/GIEL TMR0IE
Name
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR1
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
PIR1
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
CREN
ADDEN
FERR
OERR
RX9D
247
RCREG
RCSTA
EUSART Receive Register
SPEN
RX9
SREN
247
SPBRG
EUSART Baud Rate Generator Register, Low Byte
247
SPBRGH
EUSART Baud Rate Generator Register, High Byte
247
TXSTA
CSRC
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
247
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.
DS40001365F-page 196
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
16.0
ANALOG-TO-DIGITAL
CONVERTER (ADC) MODULE
The Analog-to-Digital Converter (ADC) allows
conversion of an analog input signal to a 10-bit binary
representation of that signal. This device uses analog
inputs, which are multiplexed into a single sample and
hold circuit. The output of the sample and hold is
connected to the input of the converter. The converter
generates a 10-bit binary result via successive
approximation and stores the conversion result into the
ADC result registers (ADRESL and ADRESH).
The ADC voltage reference is software selectable to
either VDD, or a voltage applied to the external reference
pins.
The ADC can generate an interrupt upon completion of
a conversion. This interrupt can be used to wake-up the
device from Sleep.
Figure 16-1 shows the block diagram of the ADC.
FIGURE 16-1:
ADC BLOCK DIAGRAM
NVCFG[1:0] = 00
AVSS
NVCFG[1:0] = 01
VREF-
AVDD
PVCFG[1:0] = 00
VREF+
PVCFG[1:0] = 01
FVR
AN0
0000
AN1
0001
AN2
0010
AN3
0011
AN4
0100
AN5
0101
AN6
0110
AN7
0111
AN8
1000
AN9
1001
AN10
1010
AN11
1011
Unused
1100
Unused
1101
DAC
1110
FVR
1111
PVCFG[1:0] = 10
ADC
10
GO/DONE
ADFM
0 = Left Justify
1 = Right Justify
ADON
10
VSS
ADRESH
ADRESL
CHS
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DS40001365F-page 197
PIC18(L)F1XK22
16.1
ADC Configuration
When configuring and using the ADC the following
functions must be considered:
•
•
•
•
•
•
Port configuration
Channel selection
ADC voltage reference selection
ADC conversion clock source
Interrupt control
Results formatting
16.1.1
PORT CONFIGURATION
The ANSEL, ANSELH, TRISA, TRISB and TRISE
registers all configure the A/D port pins. Any port pin
needed as an analog input should have its
corresponding ANSx bit set to disable the digital input
buffer and TRISx bit set to disable the digital output
driver. If the TRISx bit is cleared, the digital output level
(VOH or VOL) will be converted.
The A/D operation is independent of the state of the
ANSx bits and the TRIS bits.
Note 1: When reading the PORT register, all pins
with their corresponding ANSx bit set
read as cleared (a low level). However,
analog conversion of pins configured as
digital inputs (ANSx bit cleared and
TRISx bit set) will be accurately
converted.
2: Analog levels on any pin with the
corresponding ANSx bit cleared may
cause the digital input buffer to consume
current out of the device’s specification
limits.
16.1.2
CHANNEL SELECTION
The CHS bits of the ADCON0 register determine which
channel is connected to the sample and hold circuit.
When changing channels, a delay is required before
starting the next conversion. Refer to Section 16.2
“ADC Operation” for more information.
16.1.3
ADC VOLTAGE REFERENCE
The PVCFG and NVCFG bits of the ADCON1 register
provide independent control of the positive and
negative voltage references, respectively. The positive
voltage reference can be either VDD, FVR or an
external voltage source. The negative voltage
reference can be either VSS or an external voltage
source.
DS40001365F-page 198
16.1.4
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.
Acquisition time is set with the ACQT bits of the
ADCON2 register. Acquisition delays cover 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 is no need to wait for an acquisition time between
selecting a channel and setting the GO/DONE bit.
Manual
acquisition
is
selected
when
ACQT = 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 ACQT 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. When an acquisition time is programmed, there
is no indication of when the acquisition time ends and
the conversion begins.
16.1.5
CONVERSION CLOCK
The source of the conversion clock is software
selectable via the ADCS bits of the ADCON2 register.
There are seven possible clock options:
•
•
•
•
•
•
•
FOSC/2
FOSC/4
FOSC/8
FOSC/16
FOSC/32
FOSC/64
FRC (dedicated internal oscillator)
The time to complete one bit conversion is defined as
TAD. One full 10-bit conversion requires 11 TAD periods
as shown in Figure 16-3.
For correct conversion, the appropriate TAD specification
must be met. See A/D conversion requirements in
Table 26-20 for more information. Table 16-1 gives
examples of appropriate ADC clock selections.
Note:
Unless using the FRC, any changes in the
system clock frequency will change the
ADC clock frequency, which may
adversely affect the ADC result.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
16.1.6
INTERRUPTS
This interrupt can be generated while the device is
operating or while in Sleep. If the device is in Sleep, the
interrupt will wake-up the device. Upon waking from
Sleep, the next instruction following the SLEEP
instruction is always executed. If the user is attempting
to wake-up from Sleep and resume in-line code
execution, the global interrupt must be disabled. If the
global interrupt is enabled, execution will switch to the
Interrupt Service Routine. Please see Section 16.1.6
“Interrupts” for more information.
The ADC module allows for the ability to generate an
interrupt upon completion of an Analog-to-Digital
Conversion. The ADC interrupt flag is the ADIF bit in
the PIR1 register. The ADC interrupt enable is the ADIE
bit in the PIE1 register. The ADIF bit must be cleared by
software.
The ADIF bit is set at the completion of
every conversion, regardless of whether
or not the ADC interrupt is enabled.
Note:
TABLE 16-1:
ADC CLOCK PERIOD (TAD) vs. DEVICE OPERATING FREQUENCIES
ADC Clock Period (TAD)
ADC Clock Source
ADCS
48 MHz
16 MHz
ns(2)
4 MHz
ns(2)
1 MHz
2.0 s
ns(2)
FOSC/2
000
41.67
FOSC/4
100
83.33 ns(2)
250 ns(2)
1.0 s
4.0 s
FOSC/8
001
167 ns(2)
500 ns(2)
2.0 s
8.0 s(3)
FOSC/16
101
333 ns(2)
1.0 s
4.0 s
16.0 s(3)
FOSC/32
010
667 ns(2)
2.0 s
8.0 s(3)
32.0 s(3)
s(3)
64.0 s(3)
1-4 s(1,4)
1-4 s(1,4)
125
500
FOSC/64
110
1.33 s
4.0 s
FRC
x11
1-4 s(1,4)
1-4 s(1,4)
Legend:
Note 1:
2:
3:
4:
16.1.7
Device Frequency (FOSC)
16.0
Shaded cells are outside of recommended range.
The FRC source has a typical TAD time of 1.7 s.
These values violate the minimum required TAD time.
For faster conversion times, the selection of another clock source is recommended.
When the device frequency is greater than 1 MHz, the FRC clock source is only recommended if the
conversion will be performed during Sleep.
RESULT FORMATTING
The 10-bit A/D conversion result can be supplied in two
formats, left justified or right justified. The ADFM bit of
the ADCON2 register controls the output format.
Figure 16-2 shows the two output formats.
FIGURE 16-2:
10-BIT A/D CONVERSION RESULT FORMAT
ADRESH
(ADFM = 0)
ADRESL
MSB
LSB
bit 7
bit 0
bit 7
10-bit A/D Result
bit 0
Unimplemented: Read as ‘0’
MSB
(ADFM = 1)
bit 7
Unimplemented: Read as ‘0’
2009-2016 Microchip Technology Inc.
LSB
bit 0
bit 7
bit 0
10-bit A/D Result
DS40001365F-page 199
PIC18(L)F1XK22
16.2
Figure 16-3 shows the operation of the A/D converter
after the GO bit has been set and the ACQT bits
are cleared. A conversion is started after the following
instruction to allow entry into SLEEP mode before the
conversion begins.
ADC Operation
16.2.1
STARTING A CONVERSION
To enable the ADC module, the ADON bit of the
ADCON0 register must be set to a ‘1’. Setting the GO/
DONE bit of the ADCON0 register to a ‘1’ will,
depending on the ACQT bits of the ADCON2 register,
either immediately start the Analog-to-Digital
conversion or start an acquisition delay followed by the
Analog-to-Digital conversion.
FIGURE 16-3:
Figure 16-4 shows the operation of the A/D converter
after the GO bit has been set and the ACQT bits
are set to ‘010’ which selects a 4 TAD acquisition time
before the conversion starts.
The GO/DONE bit should not be set in the
same instruction that turns on the ADC.
Refer to Section 16.2.9 “A/D Conversion Procedure”.
Note:
A/D CONVERSION TAD CYCLES (ACQT = 000, TACQ = 0)
TCY - TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11 2 TAD
b4
b1
b0
b6
b7
b2
b9
b8
b3
b5
Conversion starts
Discharge
Holding capacitor is disconnected from analog input (typically 100 ns)
Set GO bit
On the following cycle:
ADRESH:ADRESL is loaded, GO bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
FIGURE 16-4:
A/D CONVERSION TAD CYCLES (ACQT = 010, TACQ = 4 TAD)
TAD Cycles
TACQT Cycles
1
2
3
Automatic
Acquisition
Time
4
1
3
4
5
6
7
8
9
10
11
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
Conversion starts
(Holding capacitor is disconnected from analog input)
Set GO bit
(Holding capacitor continues
acquiring input)
DS40001365F-page 200
2
2 TAD
Discharge
On the following cycle:
ADRESH:ADRESL is loaded, GO bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
16.2.2
COMPLETION OF A CONVERSION
When the conversion is complete, the ADC module will:
• Clear the GO/DONE bit
• Set the ADIF flag bit
• Update the ADRESH:ADRESL registers with new
conversion result
16.2.3
DISCHARGE
The discharge phase is used to initialize the value of
the capacitor array. The array is discharged after 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.
16.2.4
TERMINATING A CONVERSION
If a conversion must be terminated before completion,
the GO/DONE bit can be cleared by software. The
ADRESH:ADRESL registers will be updated with the
partially complete Analog-to-Digital conversion
sample. Unconverted bits will match the last bit
converted.
Note:
16.2.5
A device Reset forces all registers to their
Reset state. Thus, the ADC module is
turned off and any pending conversion is
terminated.
16.2.7
ADC OPERATION DURING SLEEP
The ADC module can operate during Sleep. This
requires the ADC clock source to be set to the FRC
option. When the FRC clock source is selected, the
ADC waits one additional instruction before starting the
conversion. This allows the SLEEP instruction to be
executed, which can reduce system noise during the
conversion. If the ADC interrupt is enabled, the device
will wake-up from Sleep when the conversion
completes. If the ADC interrupt is disabled, the ADC
module is turned off after the conversion completes,
although the ADON bit remains set.
When the ADC clock source is something other than
FRC, a SLEEP instruction causes the present
conversion to be aborted and the ADC module is
turned off, although the ADON bit remains set.
16.2.8
SPECIAL EVENT TRIGGER
The CCP1 Special Event Trigger allows periodic ADC
measurements without software intervention. When
this trigger occurs, the GO/DONE bit is set by hardware
and the Timer1 or Timer3 counter resets to zero.
Using the Special Event Trigger does not assure proper
ADC timing. It is the user’s responsibility to ensure that
the ADC timing requirements are met.
See Section 13.3.4 “Special Event Trigger” for more
information.
DELAY BETWEEN CONVERSIONS
After the A/D conversion is completed or aborted, a
2 TAD wait is required before the next acquisition can
be started. After this wait, the currently selected
channel is reconnected to the charge holding capacitor
commencing the next acquisition.
16.2.6
ADC OPERATION IN POWERMANAGED 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 ACQT and
ADCS 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 FRC
clock source should be selected.
2009-2016 Microchip Technology Inc.
DS40001365F-page 201
PIC18(L)F1XK22
16.2.9
A/D CONVERSION PROCEDURE
This is an example procedure for using the ADC to
perform an Analog-to-Digital conversion:
1.
2.
3.
4.
5.
6.
7.
8.
Configure Port:
• Disable pin output driver (See TRIS register)
• Configure pin as analog
Configure the ADC module:
• Select ADC conversion clock
• Configure voltage reference
• Select ADC input channel
• Select result format
• Select acquisition delay
• Turn on ADC module
Configure ADC interrupt (optional):
• Clear ADC interrupt flag
• Enable ADC interrupt
• Enable peripheral interrupt
• Enable global interrupt(1)
Wait the required acquisition time(2).
Start conversion by setting the GO/DONE bit.
Wait for ADC conversion to complete by one of
the following:
• Polling the GO/DONE bit
• Waiting for the ADC interrupt (interrupts
enabled)
Read ADC Result
Clear the ADC interrupt flag (required if interrupt
is enabled).
EXAMPLE 16-1:
A/D CONVERSION
;This code block configures the ADC
;for polling, Vdd and Vss as reference, Frc
clock and AN4 input.
;
;Conversion start & polling for completion
; are included.
;
MOVLW
B’10101111’ ;right justify, Frc,
MOVWF
ADCON2
; & 12 TAD ACQ time
MOVLW
B’00000000’ ;ADC ref = Vdd,Vss
MOVWF
ADCON1
;
BSF
TRISC,0
;Set RC0 to input
BSF
ANSEL,4
;Set RC0 to analog
MOVLW
B’00010001’ ;AN4, ADC on
MOVWF
ADCON0
;
BSF
ADCON0,GO
;Start conversion
ADCPoll:
BTFSC
ADCON0,GO
;Is conversion done?
BRA
ADCPoll
;No, test again
; Result is complete - store 2 MSbits in
; RESULTHI and 8 LSbits in RESULTLO
MOVFF
ADRESH,RESULTHI
MOVFF
ADRESL,RESULTLO
Note 1: The global interrupt can be disabled if the
user is attempting to wake-up from Sleep
and resume in-line code execution.
2: Software delay required if ACQT bits are
set to zero delay. See Section 16.3 “A/D
Acquisition Requirements”.
DS40001365F-page 202
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
16.2.10
ADC REGISTER DEFINITIONS
The following registers are used to control the
operation of the ADC.
Note:
Analog pin control is performed by the
ANSEL and ANSELH registers. For
ANSEL and ANSELH registers, see
Register 8-14
and
Register 8-15,
respectively.
REGISTER 16-1:
ADCON0: A/D CONTROL REGISTER 0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
CHS3
CHS2
CHS1
CHS0
GO/DONE
ADON
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-6
Unimplemented: Read as ‘0’
bit 5-2
CHS: Analog Channel Select bits
0000 = AN0
0001 = AN1
0010 = AN2
0011 = AN3
0100 = AN4
0101 = AN5
0110 = AN6
0111 = AN7
1000 = AN8
1001 = AN9
1010 = AN10
1011 = AN11
1100 = Reserved
1101 = Reserved
1110 = DAC(2)
1111 = FVR(2)
bit 1
GO/DONE: A/D Conversion Status bit
1 = A/D conversion cycle in progress. Setting this bit starts an A/D conversion cycle.
This bit is automatically cleared by hardware when the A/D conversion has completed.
0 = A/D conversion completed/not in progress
bit 0
ADON: ADC Enable bit
1 = ADC is enabled
0 = ADC is disabled and consumes no operating current
Note 1:
2:
Selecting reserved channels will yield unpredictable results as unimplemented input channels are left
floating.
See Section 20.0 “Fixed Voltage Reference (FVR)” for more information.
2009-2016 Microchip Technology Inc.
DS40001365F-page 203
PIC18(L)F1XK22
REGISTER 16-2:
ADCON1: A/D CONTROL REGISTER 1
U-0
U-0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
—
—
PVCFG1
PVCFG0
NVCFG1
NVCFG0
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
Unimplemented: Read as ‘0’
bit 3-2
PVCFG: Positive Voltage Reference select bit
00 = Positive voltage reference supplied internally by VDD.
01 = Positive voltage reference supplied externally through VREF+ pin.
10 = Positive voltage reference supplied internally through FVR.
11 = Reserved.
bit 1-0
NVCFG: Negative Voltage Reference select bit
00 = Negative voltage reference supplied internally by VSS.
01 = Negative voltage reference supplied externally through VREF- pin.
10 = Reserved.
11 = Reserved.
DS40001365F-page 204
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 16-3:
ADCON2: A/D CONTROL REGISTER 2
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
bit 7
x = Bit is unknown
ADFM: A/D Conversion Result Format Select bit
1 = Right justified
0 = Left justified
bit 6
Unimplemented: Read as ‘0’
bit 5-3
ACQT: A/D Acquisition Time Select bits. Acquisition time is the duration that the A/D charge
holding capacitor remains connected to A/D channel from the instant the GO/DONE bit is set until
conversions begins.
000 = 0(1)
001 = 2 TAD
010 = 4 TAD
011 = 6 TAD
100 = 8 TAD
101 = 12 TAD
110 = 16 TAD
111 = 20 TAD
bit 2-0
ADCS: A/D Conversion Clock Select bits
000 = FOSC/2
001 = FOSC/8
010 = FOSC/32
011 = FRC(1) (clock derived from a dedicated internal oscillator = 600 kHz nominal)
100 = FOSC/4
101 = FOSC/16
110 = FOSC/64
111 = FRC(1) (clock derived from a dedicated internal oscillator = 600 kHz nominal)
Note 1:
When the A/D clock source is selected as FRC then the start of conversion is delayed by one instruction
cycle after the GO/DONE bit is set to allow the SLEEP instruction to be executed.
2009-2016 Microchip Technology Inc.
DS40001365F-page 205
PIC18(L)F1XK22
REGISTER 16-4:
ADRESH: ADC RESULT REGISTER HIGH (ADRESH) ADFM = 0
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
ADRES9
ADRES8
ADRES7
ADRES6
ADRES5
ADRES4
ADRES3
ADRES2
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
bit 7-0
x = Bit is unknown
ADRES: ADC Result Register bits
Upper 8 bits of 10-bit conversion result
REGISTER 16-5:
ADRESL: ADC RESULT REGISTER LOW (ADRESL) ADFM = 0
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
ADRES1
ADRES0
—
—
—
—
—
—
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
bit 7-6
ADRES: ADC Result Register bits
Lower 2 bits of 10-bit conversion result
bit 5-0
Reserved: Do not use.
REGISTER 16-6:
x = Bit is unknown
ADRESH: ADC RESULT REGISTER HIGH (ADRESH) ADFM = 1
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
—
—
—
—
—
—
ADRES9
ADRES8
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
bit 7-2
Reserved: Do not use.
bit 1-0
ADRES: ADC Result Register bits
Upper 2 bits of 10-bit conversion result
REGISTER 16-7:
x = Bit is unknown
ADRESL: ADC RESULT REGISTER LOW (ADRESL) ADFM = 1
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
ADRES7
ADRES6
ADRES5
ADRES4
ADRES3
ADRES2
ADRES1
ADRES0
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
bit 7-0
x = Bit is unknown
ADRES: ADC Result Register bits
Lower 8 bits of 10-bit conversion result
DS40001365F-page 206
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
16.3
A/D Acquisition Requirements
For the ADC to meet its specified accuracy, the charge
holding capacitor (CHOLD) must be allowed to fully
charge to the input channel voltage level. The Analog
Input model is shown in Figure 16-5. 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), see Figure 16-5.
The maximum recommended impedance for analog
EQUATION 16-1:
sources is 10 k.. As the source impedance is
decreased, the acquisition time may be decreased.
After the analog input channel is selected (or changed),
an A/D acquisition must be done before the conversion
can be started. To calculate the minimum acquisition
time, Equation 16-1 may be used. This equation
assumes that 1/2 LSb error is used (1024 steps for the
ADC). The 1/2 LSb error is the maximum error allowed
for the ADC to meet its specified resolution.
ACQUISITION TIME EXAMPLE
Temperature = 50°C and external impedance of 10k 3.0V V DD
Assumptions:
T ACQ = Amplifier Settling Time + Hold Capacitor Charging Time + Temperature Coefficient
= T AMP + T C + T COFF
= 5µs + T C + Temperature - 25°C 0.05µs/°C
The value for TC can be approximated with the following equations:
1
V AP PLIE D 1 – ------------ = V CHOLD
2047
;[1] VCHOLD charged to within 1/2 lsb
–TC
----------
RC
V AP P LI ED 1 – e = V CHOLD
;[2] VCHOLD charge response to VAPPLIED
– Tc
---------
1
RC
V AP P LIED 1 – e = V A P PLIE D 1 – ------------
2047
;combining [1] and [2]
Solving for TC:
T C = – C HOLD R IC + R SS + R S ln(1/2047)
= – 13.5pF 1k + 700 + 10k ln(0.0004885)
= 1.20 µs
Therefore:
T ACQ = 5µs + 1.20µs + 50°C- 25°C 0.05µs/°C
= 7.45µs
Note 1: The reference voltage (VREF) has no
effect on the equation, since it cancels
itself out.
2: The charge holding capacitor (CHOLD) is
discharged after each conversion.
3: The maximum recommended impedance
for analog sources is 10 k. This is
required to meet the pin
leakage specification.
2009-2016 Microchip Technology Inc.
DS40001365F-page 207
PIC18(L)F1XK22
FIGURE 16-5:
ANALOG INPUT MODEL
VDD
ANx
Rs
CPIN
5 pF
VA
VT = 0.6V
VT = 0.6V
RIC 1k
Sampling
Switch
SS Rss
CHOLD = 13.5 pF
I LEAKAGE(1)
Legend: CPIN
= Input Capacitance
= Threshold Voltage
VT
I LEAKAGE = Leakage current at the pin due to
various junctions
RIC
= Interconnect Resistance
SS
= Sampling Switch
CHOLD
= Sample/Hold Capacitance
Note 1:
VDD
Discharge
Switch
VSS/VREF-
3.5V
3.0V
2.5V
2.0V
1.5V
.1
1
10
Rss (k)
100
See Section 26.0 “Electrical Specifications”.
FIGURE 16-6:
ADC TRANSFER FUNCTION
Full-Scale Range
3FFh
3FEh
ADC Output Code
3FDh
3FCh
1/2 LSB ideal
3FBh
Full-Scale
Transition
004h
003h
002h
001h
000h
Analog Input Voltage
1/2 LSB ideal
VSS/VREF-
DS40001365F-page 208
Zero-Scale
Transition
VDD/VREF+
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 16-2:
Name
REGISTERS ASSOCIATED WITH A/D OPERATION
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
ADRESH
A/D Result Register, High Byte
247
ADRESL
A/D Result Register, Low Byte
247
ADCON0
—
—
CHS3
CHS2
CHS1
CHS0
GO/DONE
ADON
247
ADCON1
—
—
—
—
PVCFG1
PVCFG0
NVCFG1
NVCFG0
247
ADCON2
ADFM
—
ACQT2
ACQT1
ACQT0
ADCS2
ADCS1
ADCS0
247
ANSEL
ANS7
ANS6
ANS5
ANS4
ANS3
ANS2
ANS1
ANS0
248
—
—
—
—
ANS11
ANS10
ANS9
ANS8
248
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
ANSELH
INTCON
GIE/GIEH PEIE/GIEL
—
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
248
PIE1
—
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
248
PIR1
—
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
248
TRISA2
TRISA1
TRISA0
248
IPR1
TRISA
—
—
TRISA5
TRISA4
—(1)
TRISB
TRISB7
TRISB6
TRISB5
TRISB4
—
—
—
—
248
TRISC
TRISC7
TRISC6
TRISC5
TRISC4
TRISC3
TRISC2
TRISC1
TRISC0
248
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.
Note 1: Unimplemented, read as ‘1’.
2009-2016 Microchip Technology Inc.
DS40001365F-page 209
PIC18(L)F1XK22
17.0
COMPARATOR MODULE
Comparators are used to interface analog circuits to a
digital circuit by comparing two analog voltages and
providing a digital indication of their relative magnitudes.
The comparators are very useful mixed signal building
blocks because they provide analog functionality
independent of the program execution. The Analog
Comparator module includes the following features:
•
•
•
•
•
•
•
•
•
Independent comparator control
Programmable input selection
Comparator output is available internally/externally
Programmable output polarity
Interrupt-on-Change
Wake-up from Sleep
Programmable Speed/Power optimization
PWM shutdown
Programmable and fixed voltage reference
17.1
Comparator Overview
FIGURE 17-1:
SINGLE COMPARATOR
VIN+
+
VIN-
–
Output
VINVIN+
Output
Note:
The black areas of the output of the
comparator represents the uncertainty
due to input offsets and response time.
A single comparator is shown in Figure 17-1 along with
the relationship between the analog input levels and
the digital output. When the analog voltage at VIN+ is
less than the analog voltage at VIN-, the output of the
comparator is a digital low level. When the analog
voltage at VIN+ is greater than the analog voltage at
VIN-, the output of the comparator is a digital high level.
DS40001365F-page 210
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 17-2:
COMPARATOR C1 SIMPLIFIED BLOCK DIAGRAM
C1CH
2
D
Q1
C12IN0-
0
C12IN1C12IN2-
1
MUX
2
C12IN3-
3
To
Data Bus
Q
EN
RD_CM1CON0
D
Q3*RD_CM1CON0
Q
Set C1IF
EN
CL
NReset
C1ON(1)
C1R
C1VINC1IN+
DAC Output
FVR
0
MUX
1
C1VIN+
0
MUX
C1VREF
1
-
C1SP
To PWM Logic
C1OUT
C1
+
C1POL
C1SYNC
C1OE
0
C1RSEL
D
From TMR1L[0]
Q
1
C1OUT
(4)
SYNCC1OUT
Note 1:
2:
3:
4:
2009-2016 Microchip Technology Inc.
When C1ON = 0, the C1 comparator will produce a ‘0’ output to the XOR Gate.
Q1 and Q3 are phases of the four-phase system clock (FOSC).
Q1 is held high during Sleep mode.
Positive going pulse generated on both falling and rising edges of the bit.
DS40001365F-page 211
PIC18(L)F1XK22
FIGURE 17-3:
COMPARATOR C2 SIMPLIFIED BLOCK DIAGRAM
D
Q1
To
Data Bus
Q
EN
RD_CM2CON0
C2CH
2
D
Set C2IF
Q
Q3*RD_CM2CON0
C12IN0-
0
C12IN1C12IN2-
1
MUX
2
C12IN3-
3
C2R
EN
CL
NRESET
C2ON(1)
C2VINC2VIN+
To PWM Logic
C2OUT
C2
C2SP
C2SYNC
C2POL
0
C2IN+
DAC Output
FVR
0
MUX
1
0
MUX
C2VREF
1
D
From TMR1L[0]
(4)
Q
C20E
C2OUT pin
1
SYNCC2OUT
C2RSEL
Note 1:
2:
3:
4:
DS40001365F-page 212
When C2ON = 0, the C2 comparator will produce a ‘0’ output to the XOR Gate.
Q1 and Q3 are phases of the four-phase system clock (FOSC).
Q1 is held high during Sleep mode.
Positive going pulse generated on both falling and rising edges of the bit.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
17.2
Comparator Control
Each comparator has a separate control and
Configuration register: CM1CON0 for Comparator C1
and CM2CON0 for Comparator C2. In addition,
Comparator C2 has a second control register,
CM2CON1, for controlling the interaction with Timer1 and
simultaneous reading of both comparator outputs.
The CM1CON0 and CM2CON0 registers (see Registers
17-1 and 17-2, respectively) contain the control and
status bits for the following:
•
•
•
•
•
•
Enable
Input selection
Reference selection
Output selection
Output polarity
Speed selection
17.2.1
COMPARATOR ENABLE
Setting the CxON bit of the CMxCON0 register enables
the comparator for operation. Clearing the CxON bit
disables the comparator resulting in minimum current
consumption.
17.2.2
COMPARATOR INPUT SELECTION
The CxCH bits of the CMxCON0 register direct
one of four analog input pins to the comparator
inverting input.
Note:
17.2.3
To use CxIN+ and C12INx- pins as analog
inputs, the appropriate bits must be set in
the
ANSEL
register
and
the
corresponding TRIS bits must also be set
to disable the output drivers.
COMPARATOR REFERENCE
SELECTION
Setting the CxR bit of the CMxCON0 register directs an
internal voltage reference or an analog input pin to the
noninverting input of the comparator. See Section 20.0
“Fixed Voltage Reference (FVR)” for more
information on the Internal Voltage Reference module.
17.2.4
COMPARATOR OUTPUT
SELECTION
The output of the comparator can be monitored by
reading either the CxOUT bit of the CMxCON0 register
or the MCxOUT bit of the CM2CON1 register. In order
to make the output available for an external connection,
the following conditions must be true:
Note 1: The CxOE bit overrides the PORT data
latch. Setting the CxON has no impact on
the port override.
2: The internal output of the comparator is
latched with each instruction cycle.
Unless otherwise specified, external
outputs are not latched.
17.2.5
COMPARATOR OUTPUT POLARITY
Inverting the output of the comparator is functionally
equivalent to swapping the comparator inputs. The
polarity of the comparator output can be inverted by
setting the CxPOL bit of the CMxCON0 register.
Clearing the CxPOL bit results in a non-inverted output.
Table 17-1 shows the output state versus input
conditions, including polarity control.
TABLE 17-1:
COMPARATOR OUTPUT
STATE vs. INPUT
CONDITIONS
Input Condition
CxPOL
CxOUT
CxVIN- > CxVIN+
0
0
CxVIN- < CxVIN+
0
1
CxVIN- > CxVIN+
1
1
CxVIN- < CxVIN+
1
0
17.2.6
COMPARATOR SPEED SELECTION
The trade-off between speed or power can be
optimized during program execution with the CxSP
control bit. The default state for this bit is ‘1’ which
selects the normal speed mode. Device power
consumption can be optimized at the cost of slower
comparator propagation delay by clearing the CxSP bit
to ‘0’.
17.3
Comparator Response Time
The comparator output is indeterminate for a period of
time after the change of an input source or the selection
of a new reference voltage. This period is referred to as
the response time. The response time of the
comparator differs from the settling time of the voltage
reference. Therefore, both of these times must be
considered when determining the total response time
to a comparator input change. See the Comparator and
Voltage Reference Specifications in Section 26.0
“Electrical Specifications” for more details.
• CxOE bit of the CMxCON0 register must be set
• Corresponding TRIS bit must be cleared
• CxON bit of the CMxCON0 register must be set
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17.4
Comparator Interrupt Operation
The comparator interrupt flag can be set whenever
there is a change in the output value of the comparator.
Changes are recognized by means of a mismatch
circuit which consists of two latches and an exclusiveor gate (see Figure 17-2 and Figure 17-3). One latch is
updated with the comparator output level when the
CMxCON0 register is read. This latch retains the value
until the next read of the CMxCON0 register or the
occurrence of a Reset. The other latch of the mismatch
circuit is updated on every Q1 system clock. A
mismatch condition will occur when a comparator
output change is clocked through the second latch on
the Q1 clock cycle. At this point the two mismatch
latches have opposite output levels which is detected
by the exclusive-or gate and fed to the interrupt
circuitry. The mismatch condition persists until either
the CMxCON0 register is read or the comparator
output returns to the previous state.
Note 1: A write operation to the CMxCON0
register will also clear the mismatch
condition because all writes include a read
operation at the beginning of the write
cycle.
17.4.1
PRESETTING THE MISMATCH
LATCHES
The comparator mismatch latches can be preset to the
desired state before the comparators are enabled.
When the comparator is off the CxPOL bit controls the
CxOUT level. Set the CxPOL bit to the desired CxOUT
non-interrupt level while the CxON bit is cleared. Then,
configure the desired CxPOL level in the same
instruction that the CxON bit is set. Since all register
writes are performed as a Read-Modify-Write, the
mismatch latches will be cleared during the instruction
Read phase and the actual configuration of the CxON
and CxPOL bits will be occur in the final Write phase.
FIGURE 17-4:
COMPARATOR
INTERRUPT TIMING W/O
CMxCON0 READ
Q1
Q3
CxIN+
TRT
CxIN
Set CxIF (edge)
CxIF
Reset by Software
2: Comparator interrupts will operate
correctly regardless of the state of CxOE.
The comparator interrupt is set by the mismatch edge
and not the mismatch level. This means that the
interrupt flag can be reset without the additional step of
reading or writing the CMxCON0 register to clear the
mismatch registers. When the mismatch registers are
cleared, an interrupt will occur upon the comparator’s
return to the previous state, otherwise no interrupt will
be generated.
FIGURE 17-5:
Software will need to maintain information about the
status of the comparator output, as read from the
CMxCON0 register, or CM2CON1 register, to determine
the actual change that has occurred. See Figures 17-4
and 17-5.
Set CxIF (edge)
The CxIF bit of the PIR2 register is the comparator
interrupt flag. This bit must be reset by software by
clearing it to ‘0’. Since it is also possible to write a ‘1’ to
this register, an interrupt can be generated.
In mid-range Compatibility mode the CxIE bit of the
PIE2 register and the PEIE and GIE bits of the INTCON
register must all be set to enable comparator interrupts.
If any of these bits are cleared, the interrupt is not
enabled, although the CxIF bit of the PIR2 register will
still be set if an interrupt condition occurs.
DS40001365F-page 214
COMPARATOR
INTERRUPT TIMING WITH
CMxCON0 READ
Q1
Q3
CxIN+
TRT
CxOUT
CxIF
Cleared by CMxCON0 Read
Reset by Software
Note 1: If a change in the CMxCON0 register
(CxOUT) should occur when a read
operation is being executed (start of the
Q2 cycle), then the CxIF interrupt flag of
the PIR2 register may not get set.
2: When either comparator is first enabled,
bias circuitry in the comparator module
may cause an invalid output from the
comparator until the bias circuitry is
stable. Allow about 1 s for bias settling
then clear the mismatch condition and
interrupt flags before enabling comparator
interrupts.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
17.5
Operation During Sleep
The comparator, if enabled before entering Sleep mode,
remains active during Sleep. The additional current
consumed by the comparator is shown separately in
Section 26.0 “Electrical Specifications”. If the
comparator is not used to wake the device, power
consumption can be minimized while in Sleep mode by
turning off the comparator. Each comparator is turned off
by clearing the CxON bit of the CMxCON0 register.
A change to the comparator output can wake-up the
device from Sleep. To enable the comparator to wake
the device from Sleep, the CxIE bit of the PIE2 register
and the PEIE bit of the INTCON register must be set.
The instruction following the SLEEP instruction always
executes following a wake from Sleep. If the GIE bit of
the INTCON register is also set, the device will then
execute the Interrupt Service Routine.
17.6
Effects of a Reset
A device Reset forces the CMxCON0 and CM2CON1
registers to their Reset states. This forces both
comparators and the voltage references to their Off
states.
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DS40001365F-page 215
PIC18(L)F1XK22
REGISTER 17-1:
CM1CON0: COMPARATOR 1 CONTROL REGISTER 0
R/W-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
C1ON
C1OUT
C1OE
C1POL
C1SP
C1R
C1CH1
C1CH0
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
bit 7
C1ON: Comparator C1 Enable bit
1 = Comparator C1 is enabled
0 = Comparator C1 is disabled
bit 6
C1OUT: Comparator C1 Output bit
If C1POL = 1 (inverted polarity):
C1OUT = 0 when C1VIN+ > C1VINC1OUT = 1 when C1VIN+ < C1VINIf C1POL = 0 (non-inverted polarity):
C1OUT = 1 when C1VIN+ > C1VINC1OUT = 0 when C1VIN+ < C1VIN-
bit 5
C1OE: Comparator C1 Output Enable bit
1 = C1OUT is present on the C1OUT pin(1)
0 = C1OUT is internal only
bit 4
C1POL: Comparator C1 Output Polarity Select bit
1 = C1OUT logic is inverted
0 = C1OUT logic is not inverted
bit 3
C1SP: Comparator C1 Speed/Power Select bit
1 = C1 operates in normal power, higher speed mode
0 = C1 operates in low-power, low-speed mode
bit 2
C1R: Comparator C1 Reference Select bit (noninverting input)
1 = C1VIN+ connects to C1VREF output
0 = C1VIN+ connects to C12IN+ pin
bit 1-0
C1CH: Comparator C1 Channel Select bit
00 = C12IN0- pin of C1 connects to C1VIN01 = C12IN1- pin of C1 connects to C1VIN10 = C12IN2- pin of C1 connects to C1VIN11 = C12IN3- pin of C1 connects to C1VIN-
Note 1:
x = Bit is unknown
Comparator output requires the following three conditions: C1OE = 1, C1ON = 1 and corresponding port
TRIS bit = 0.
DS40001365F-page 216
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 17-2:
CM2CON0: COMPARATOR 2 CONTROL REGISTER 0
R/W-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
C2ON
C2OUT
C2OE
C2POL
C2SP
C2R
C2CH1
C2CH0
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
bit 7
C2ON: Comparator C2 Enable bit
1 = Comparator C2 is enabled
0 = Comparator C2 is disabled
bit 6
C2OUT: Comparator C2 Output bit
If C2POL = 1 (inverted polarity):
C2OUT = 0 when C2VIN+ > C2VINC2OUT = 1 when C2VIN+ < C2VINIf C2POL = 0 (non-inverted polarity):
C2OUT = 1 when C2VIN+ > C2VINC2OUT = 0 when C2VIN+ < C2VIN-
bit 5
C2OE: Comparator C2 Output Enable bit
1 = C2OUT is present on C2OUT pin(1)
0 = C2OUT is internal only
bit 4
C2POL: Comparator C2 Output Polarity Select bit
1 = C2OUT logic is inverted
0 = C2OUT logic is not inverted
bit 3
C2SP: Comparator C2 Speed/Power Select bit
1 = C2 operates in normal power, higher speed mode
0 = C2 operates in low-power, low-speed mode
bit 2
C2R: Comparator C2 Reference Select bits (noninverting input)
1 = C2VIN+ connects to C2VREF
0 = C2VIN+ connects to C2IN+ pin
bit 1-0
C2CH: Comparator C2 Channel Select bits
00 = C12IN0- pin of C2 connects to C2VIN01 = C12IN1- pin of C2 connects to C2VIN10 = C12IN2- pin of C2 connects to C2VIN11 = C12IN3- pin of C2 connects to C2VIN-
Note 1:
x = Bit is unknown
Comparator output requires the following three conditions: C2OE = 1, C2ON = 1 and corresponding port
TRIS bit = 0.
2009-2016 Microchip Technology Inc.
DS40001365F-page 217
PIC18(L)F1XK22
17.7
Analog Input Connection
Considerations
A simplified circuit for an analog input is shown in
Figure 17-6. Since the analog input pins share their
connection with a digital input, they have reverse
biased ESD protection diodes to VDD and VSS. The
analog input, therefore, must be between VSS and VDD.
If the input voltage deviates from this range by more
than 0.6V in either direction, one of the diodes is
forward biased and a latch-up may occur.
Note 1: When reading a PORT register, all pins
configured as analog inputs will read as a
‘0’. Pins configured as digital inputs will
convert as an analog input, according to
the input specification.
2: Analog levels on any pin defined as a
digital input, may cause the input buffer to
consume more current than is specified.
A maximum source impedance of 10 k is recommended
for the analog sources. Also, any external component
connected to an analog input pin, such as a capacitor or
a Zener diode, should have very little leakage current to
minimize inaccuracies introduced.
FIGURE 17-6:
ANALOG INPUT MODEL
VDD
VT 0.6V
Rs < 10K
AIN
VA
CPIN
5 pF
VT 0.6V
RIC
ILEAKAGE(1)
Vss
Legend: CPIN
= Input Capacitance
ILEAKAGE = Leakage Current at the pin due to various junctions
RIC
= Interconnect Resistance
= Source Impedance
RS
= Analog Voltage
VA
VT
= Threshold Voltage
Note 1: See Section 26.0 “Electrical Specifications”.
DS40001365F-page 218
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
17.8
Additional Comparator Features
There are four additional comparator features:
•
•
•
•
Simultaneous read of comparator outputs
Internal reference selection
Hysteresis selection
Output Synchronization
17.8.1
SIMULTANEOUS COMPARATOR
OUTPUT READ
The MC1OUT and MC2OUT bits of the CM2CON1
register are mirror copies of both comparator outputs.
The ability to read both outputs simultaneously from a
single register eliminates the timing skew of reading
separate registers.
Note 1: Obtaining the status of C1OUT or
C2OUT by reading CM2CON1 does not
affect the comparator interrupt mismatch
registers.
17.8.2
17.8.3
COMPARATOR HYSTERESIS
The Comparator Cx have selectable hysteresis. The
hysteresis can be enabled by setting the CxHYS bit of
the CM2CON1 register. See Section 26.0 “Electrical
Specifications” for more details.
17.8.4
SYNCHRONIZING COMPARATOR
OUTPUT TO TIMER 1
The Comparator Cx output can be synchronized with
Timer1 by setting the CxSYNC bit of the CM2CON1
register. When enabled, the Cx output is latched on
the rising edge of the Timer1 source clock. If a
prescaler is used with Timer1, the comparator output
is latched after the prescaling function. To prevent a
race condition, the comparator output is latched on
the rising edge of the Timer1 clock source and Timer1
increments on the rising edge of its clock source. See
the Comparator Block Diagram (Figure 17-2 and
Figure 17-3) and the Timer1 Block Diagram
(Figure 17-2) for more information.
INTERNAL REFERENCE
SELECTION
There are two internal voltage references available to
the noninverting input of each comparator. One of
these is the Fixed Voltage Reference (FVR) and the
other is the variable Digital-to-Analog Converter
(CVREF/DAC). The CxRSEL bit of the CM2CON
register determines which of these references is routed
to
the
Digital-to-Analog
Converter
output
(CVREF/DAC). Further routing to the comparator is
accomplished by the CxR bit of the CMxCON0 register.
See 20.0 “Fixed Voltage Reference (FVR)” and
Figure 17-2 and Figure 17-3 for more detail.
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PIC18(L)F1XK22
REGISTER 17-3:
CMCON0: COMPARATOR 2 CONTROL REGISTER 1
R-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
MC1OUT
MC2OUT
C1RSEL
C2RSEL
C1HYS
C2HYS
C1SYNC
C2SYNC
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
bit 7
MC1OUT: Mirror Copy of C1OUT bit
bit 6
MC2OUT: Mirror Copy of C2OUT bit
bit 5
C1RSEL: Comparator C1 Reference Select bit
1 = FVR routed to C1VREF input
0 = CVREF/DAC1OUT routed to C1VREF input
bit 4
C2RSEL: Comparator C2 Reference Select bit
1 = FVR routed to C2VREF input
0 = CVREF/DAC1OUT routed to C2VREF input
bit 3
C1HYS: Comparator C1 Hysteresis Enable bit
1 = Comparator C1 hysteresis enabled
0 = Comparator C1 hysteresis disabled
bit 2
C2HYS: Comparator C2 Hysteresis Enable bit
1 = Comparator C2 hysteresis enabled
0 = Comparator C2 hysteresis disabled
bit 1
C1SYNC: C1 Output Synchronous Mode bit
1 = C1 output is synchronous to rising edge to TMR1 clock
0 = C1 output is asynchronous
bit 0
C2SYNC: C2 Output Synchronous Mode bit
1 = C2 output is synchronous to rising edge to TMR1 clock
0 = C2 output is asynchronous
DS40001365F-page 220
x = Bit is unknown
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 17-2:
Name
REGISTERS ASSOCIATED WITH COMPARATOR MODULE
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
ANSEL
ANS7
ANS6
ANS5
ANS4
ANS3
ANS2
ANS1
ANS0
248
CM1CON0
C1ON
C1OUT
C1OE
C1POL
C1SP
C1R
C1CH1
C1CH0
248
CM2CON0
C2ON
C2OUT
C2OE
C2POL
C2SP
C2R
C2CH1
C2CH0
248
CM2CON1
MC1OUT
MC2OUT
C1RSEL
C2RSEL
C1HYS
C2HYS
C1SYNC
C2SYNC
248
INTCON
GIE/GIEH
PEIE/GIEL
TMR0IE
INT0IE
RABIE
TMR0IF
INT0IF
RABIF
245
IPR2
OSCFIP
C1IP
C2IP
EEIP
BCLIP
—
TMR3IP
—
248
LATC
LATC7
LATC6
LATC5
LATC4
LATC3
LATC2
LATC1
LATC0
248
PIE2
OSCFIE
C1IE
C2IE
EEIE
BCLIE
—
TMR3IE
—
248
PIR2
OSCFIF
C1IF
C2IF
EEIF
BCLIF
—
TMR3IF
—
248
RC5
RC4
RC3
RC2
RC1
RC0
248
—
—
—
—
247
—
D1NSS
247
PORTC
RC7
RC6
VREFCON0
FVR1EN
FVR1ST
VREFCON1
D1EN
D1LPS
FVR1S
DAC1OE
---
TRISA
—
—
TRISA5
TRISA4
TRISC
TRISC7
TRISC6
TRISC5
TRISC4
Legend:
Note 1:
D1PSS
—
(1)
TRISC3
TRISA2
TRISA1
TRISA0
248
TRISC2
TRISC1
TRISC0
248
— = unimplemented, read as ‘0’. Shaded cells are unused by the comparator module.
Unimplemented, read as ‘1’.
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PIC18(L)F1XK22
18.0
18.1.1
POWER-MANAGED MODES
The SCS bits allow the selection of one of three
clock sources for power-managed modes. They are:
PIC18(L)F1XK22 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).
• The primary clock, as defined by the FOSC
Configuration bits
• The secondary clock (the Timer1 oscillator)
• The internal oscillator block
There are three categories of power-managed modes:
18.1.2
• Run modes
• Idle modes
• Sleep mode
ENTERING POWER-MANAGED
MODES
Switching from one power-managed mode to another
begins by loading the OSCCON register. The
SCS 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. Refer to
Section 2.9 “Clock Switching” for more information.
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 powersaving features offered on previous PIC® microcontroller
devices. One is the clock switching feature which allows
the controller to use the Timer1 oscillator in place of the
primary oscillator. Also included is the Sleep mode,
offered by all PIC microcontroller devices, where all
device clocks are stopped.
18.1
CLOCK SOURCES
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 of the OSCCON register.
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.
Selecting Power-Managed Modes
Selecting a power-managed mode requires two
decisions:
• Whether or not the CPU is to be clocked
• The selection of a clock source
The IDLEN bit of the OSCCON register controls CPU
clocking, while the SCS bits of the OSCCON
register select the clock source. The individual modes,
bit settings, clock sources and affected modules are
summarized in Table 18-1.
TABLE 18-1:
POWER-MANAGED MODES
OSCCON Bits
Mode
Module Clocking
Available Clock and Oscillator Source
IDLEN(1)
SCS
CPU
Peripherals
0
N/A
Off
Off
PRI_RUN
N/A
00
Clocked
Clocked
SEC_RUN
N/A
01
Clocked
Clocked
Secondary – Timer1 Oscillator
RC_RUN
N/A
1x
Clocked
Clocked
Internal Oscillator Block(2)
PRI_IDLE
1
00
Off
Clocked
Primary – LP, XT, HS, HSPLL, RC, EC
SEC_IDLE
1
01
Off
Clocked
Secondary – Timer1 Oscillator
RC_IDLE
1
1x
Off
Clocked
Internal Oscillator Block(2)
Sleep
Note 1:
2:
None – All clocks are disabled
Primary – LP, XT, HS, RC, EC and Internal
Oscillator Block(2).
This is the normal full power execution mode.
IDLEN reflects its value when the SLEEP instruction is executed.
Includes HFINTOSC and HFINTOSC postscaler, as well as the LFINTOSC source.
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PIC18(L)F1XK22
18.1.3
MULTIPLE FUNCTIONS OF THE
SLEEP COMMAND
The power-managed mode that is invoked with the
SLEEP instruction is determined by the setting of the
IDLEN bit of the OSCCON register at the time the
instruction is executed. All clocks stop and minimum
power is consumed when SLEEP is executed with the
IDLEN bit cleared. The system clock continues to
supply a clock to the peripherals but is disconnected
from the CPU when SLEEP is executed with the IDLEN
bit set.
18.2
18.2.3
RC_RUN MODE
In RC_RUN mode, the CPU and peripherals are
clocked from the internal oscillator. In this mode, the
primary external oscillator is shut down. RC_RUN
mode provides the best power conservation of all the
Run modes when the LFINTOSC is the system clock.
RC_RUN mode is entered by setting the SCS1 bit.
When the clock source is switched from the primary
oscillator to the internal oscillator, 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.
Run Modes
In the Run modes, clocks to both the core and
peripherals are active. The difference between these
modes is the clock source.
18.2.1
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 2.11 “Two-Speed Start-up
Mode” for details). In this mode, the device operated
off the oscillator defined by the FOSC bits of the
CONFIGH Configuration register.
18.2.2
SEC_RUN MODE
In SEC_RUN mode, the CPU and peripherals are
clocked from the secondary external 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 SCS
bits of the OSCCON register to ‘01’. When SEC_RUN
mode is active all of the following are true:
• The main clock source is switched to the
secondary external oscillator
• Primary external oscillator is shut down
• T1RUN bit of the T1CON register is set
• OSTS bit is cleared.
Note:
The secondary external oscillator should
already be running prior to entering
SEC_RUN mode. If the T1OSCEN bit is
not set when the SCS bits are set to
‘01’, entry to SEC_RUN mode will not
occur until T1OSCEN bit is set and
secondary external oscillator is ready.
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PIC18(L)F1XK22
18.3
Sleep Mode
18.4
The
Power-Managed
Sleep
mode
in
the
PIC18(L)F1XK22 devices is identical to the legacy
Sleep mode offered in all other PIC microcontroller
devices. It is entered by clearing the IDLEN bit of the
OSCCON register and executing the SLEEP instruction.
This shuts down the selected oscillator (Figure 18-1)
and all clock source status bits are cleared.
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 by the SCS 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.
Entering the Sleep mode from either Run or Idle 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 LFINTOSC source
will continue to operate. If the Timer1 oscillator is
enabled, it will also continue to run.
If the WDT is selected, the LFINTOSC 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 SCS bits
becomes ready (see Figure 18-2), 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 23.0 “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.
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 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 SCS bits.
FIGURE 18-1:
TRANSITION TIMING FOR ENTRY TO SLEEP MODE
Q1 Q2 Q3 Q4 Q1
OSC1
CPU
Clock
Peripheral
Clock
Sleep
Program
Counter
PC
PC + 2
FIGURE 18-2:
TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL)
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1
OSC1
TOST(1)
PLL Clock
Output
TPLL(1)
CPU Clock
Peripheral
Clock
Program
Counter
PC
Wake Event
PC + 2
PC + 4
PC + 6
OSTS bit set
Note1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
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18.4.1
PRI_IDLE MODE
18.4.2
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
instruction. 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 FOSC Configuration bits. The
OSTS bit remains set (see Figure 18-3).
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 wakeup, the OSTS bit remains set. The IDLEN and SCS bits
are not affected by the wake-up (see Figure 18-4).
FIGURE 18-3:
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 SCS 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 TCSD 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 18-4).
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
main system clock will continue to operate
in the previously selected mode and the
corresponding IDLE mode will be entered
(i.e., PRI_IDLE or RC_IDLE).
TRANSITION TIMING FOR ENTRY TO IDLE MODE
Q1
Q3
Q2
Q4
Q1
OSC1
CPU Clock
Peripheral
Clock
Program
Counter
PC
FIGURE 18-4:
PC + 2
TRANSITION TIMING FOR WAKE FROM IDLE TO RUN MODE
Q1
Q2
Q3
Q4
OSC1
TCSD
CPU Clock
Peripheral
Clock
Program
Counter
PC
Wake Event
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18.4.3
RC_IDLE MODE
In RC_IDLE mode, the CPU is disabled but the
peripherals continue to be clocked from the internal
oscillator block from the HFINTOSC multiplexer output.
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. It is recommended
that SCS0 also be cleared, although its value is
ignored, to maintain software compatibility with future
devices. The HFINTOSC 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 HFINTOSC 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 HFINTOSC output is enabled.
The IOSF bit becomes set, after the HFINTOSC output
becomes stable, after an interval of TIOBST. Clocks to
the peripherals continue while the HFINTOSC source
stabilizes. If the IRCF bits were previously at a nonzero value, or INTSRC was set before the SLEEP
instruction was executed and the HFINTOSC source
was already stable, the IOSF bit will remain set. If the
IRCF bits and INTSRC are all clear, the HFINTOSC
output will not be enabled, the IOSF 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 HFINTOSC multiplexer output.
After a delay of TCSD following the wake event, the CPU
begins executing code being clocked by the
HFINTOSC multiplexer. The IDLEN and SCS bits are
not affected by the wake-up. The LFINTOSC source
will continue to run if either the WDT or the Fail-Safe
Clock Monitor is enabled.
18.5
Exiting Idle and Sleep Modes
An exit from Sleep mode or any of the Idle modes is
triggered by any one of the following:
• An interrupt
• A Reset
• A Watchdog 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 18.2
“Run
Modes”,
Section 18.3 “Sleep Mode” and Section 18.4 “Idle
Modes”).
18.5.1
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 PEIE bit must also
be set If the desired interrupt enable bit is in a PIE
register. The exit sequence is initiated when the
corresponding interrupt flag bit is set.
The instruction immediately following the SLEEP
instruction is executed on all exits by interrupt from Idle
or Sleep modes. Code execution then branches to the
interrupt vector if the GIE/GIEH bit of the INTCON
register is set, otherwise code execution continues
without branching (see Section 7.0 “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.
18.5.2
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 18.2 “Run
Modes” and Section 18.3 “Sleep Mode”). If the
device is executing code (all Run modes), the time-out
will result in a WDT Reset (see Section 23.2
“Watchdog Timer (WDT)”).
The WDT timer and postscaler are cleared by any one
of the following:
• Executing a SLEEP instruction
• Executing a CLRWDT instruction
• The loss of the currently selected clock source
when the Fail-Safe Clock Monitor is enabled
• Modifying the IRCF bits in the OSCCON register
when the internal oscillator block is the device
clock source
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18.5.3
EXIT BY RESET
18.5.4
EXIT WITHOUT AN OSCILLATOR
START-UP DELAY
Exiting Sleep and Idle modes by Reset causes code
execution to restart at address 0. See Section 22.0
“Reset” for more details.
Certain exits from power-managed modes do not
invoke the OST at all. There are two cases:
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. Exit
delays are summarized in Table 18-2.
• 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, INTOSC,
and INTOSCIO 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 18-2:
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)
LP, XT, HS
Primary Device Clock
(PRI_IDLE mode)
HSPLL
EC, RC
TCSD(1)
HFINTOSC(2)
T1OSC or LFINTOSC(1)
HFINTOSC(2)
None
(Sleep mode)
2:
3:
4:
IOSF
LP, XT, HS
TOST(3)
HSPLL
TOST + tPLL(3)
EC, RC
TCSD(1)
HFINTOSC(1)
TIOBST(4)
LP, XT, HS
TOST(4)
HSPLL
TOST + tPLL(3)
EC, RC
TCSD(1)
OSTS
IOSF
OSTS
HFINTOSC(1)
None
LP, XT, HS
TOST(3)
HSPLL
TOST + tPLL(3)
OSTS
EC, RC
TCSD(1)
TIOBST(4)
IOSF
HFINTOSC(1)
Note 1:
OSTS
IOSF
TCSD is a required delay when waking from Sleep and all Idle modes and runs concurrently with any other
required delays (see Section 18.4 “Idle Modes”). On Reset, HFINTOSC defaults to 1 MHz.
Includes both the HFINTOSC 16 MHz source and postscaler derived frequencies.
TOST is the Oscillator Start-up Timer. tPLL is the PLL Lock-out Timer (parameter F12).
Execution continues during the HFINTOSC stabilization period, TIOBST.
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PIC18(L)F1XK22
19.0
SR LATCH
19.2
The SRQEN and SRNQEN bits of the SRCON0 register
control the latch output selection. Both of the SR latch’s
outputs may be directly output to an independent I/O
pin. Control is determined by the state of bits SRQEN
and SRNQEN in registers SRCON0.
The module consists of a single SR latch with multiple
Set and Reset inputs as well as selectable latch output.
The SR latch module includes the following features:
•
•
•
•
•
Programmable input selection
SR latch output is available internally/externally
Selectable Q and Q output
Firmware Set and Reset
SR Latch
19.1
The applicable TRIS bit of the corresponding port must
be cleared to enable the port pin output driver.
19.3
The latch is a Set-Reset latch that does not depend on a
clock source. Each of the Set and Reset inputs are
active-high. The latch can be Set or Reset by CxOUT,
INT1 pin, or variable clock. Additionally the SRPS and
the SRPR bits of the SRCON0 register may be used to
Set or Reset the SR latch, respectively. The latch is
reset-dominant, therefore, if both Set and Reset inputs
are high the latch will go to the Reset state. Both the
SRPS and SRPR bits are self resetting which means
that a single write to either of the bits is all that is
necessary to complete a latch Set or Reset operation.
SR LATCH SIMPLIFIED BLOCK DIAGRAM
SRPS
Pulse
Gen(2)
INT1
SRPR
INT1
SRRPE
SRCLK
SRRCKE
SYNCC2OUT(4)
SRRC2E
SYNCC1OUT(4)
SRRC1E
SRLEN
SRQEN
S
SRSPE
SRCLK
SRSCKE
SYNCC2OUT(4)
SRSC2E
SYNCC1OUT(4)
SRSC1E
Note 1:
2:
3:
4:
Effects of a Reset
Upon any device Reset, the SR latch is not initialized.
The user’s firmware is responsible to initialize the latch
output before enabling it to the output pins.
Latch Operation
FIGURE 19-1:
Latch Output
Q
SRQ pin(3)
SR
Latch(1)
Pulse
Gen(2)
R
SRNQ pin(3)
Q
SRLEN
SRNQEN
If R = 1 and S = 1 simultaneously, Q = 0, Q = 1
Pulse generator causes a 2 Q-state pulse width.
Output shown for reference only. See I/O port pin block diagram for more detail.
Name denotes the source of connection at the comparator output.
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PIC18(L)F1XK22
TABLE 19-1:
SRCLK
SRCLK FREQUENCY TABLE
Divider
FOSC = 20 MHz
FOSC = 16 MHz
FOSC = 8 MHz FOSC = 4 MHz
FOSC = 1 MHz
111
512
25.6 s
32 s
64 s
128 s
512 s
110
256
12.8 s
16 s
32 s
64 s
256 s
101
128
6.4 s
8 s
16 s
32 s
128 s
100
64
3.2 s
4 s
8 s
16 s
64 s
011
32
1.6 s
2 s
4 s
8 s
32 s
010
16
0.8 s
1 s
2 s
4 s
16 s
001
8
0.4 s
0.5 s
1 s
2 s
8 s
000
4
0.2 s
0.25 s
0.5 s
1 s
4 s
REGISTER 19-1:
SRCON0: SR LATCH CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
SRLEN
SRCLK2
SRCLK1
SRCLK0
SRQEN
SRNQEN
SRPS
SRPR
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented
C = Clearable only bit
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
SRLEN: SR Latch Enable bit(1)
1 = SR latch is enabled
0 = SR latch is disabled
bit 6-4
SRCLK(1): SR Latch Clock divider bits
000 = 1/4 Peripheral cycle clock
001 = 1/8 Peripheral cycle clock
010 = 1/16 Peripheral cycle clock
011 = 1/32 Peripheral cycle clock
100 = 1/64 Peripheral cycle clock
101 = 1/128 Peripheral cycle clock
110 = 1/256 Peripheral cycle clock
111 = 1/512 Peripheral cycle clock
bit 3
SRQEN: SR Latch Q Output Enable bit
1 = Q is present on the SRQ pin
0 = Q is internal only
bit 2
SRNQEN: SR Latch Q Output Enable bit
1 = Q is present on the SRNQ pin
0 = Q is internal only
bit 1
SRPS: Pulse Set Input of the SR Latch bit
1 = Pulse input
0 = Always reads back ‘0’
bit 0
SRPR: Pulse Reset Input of the SR Latch bit
1 = Pulse input
0 = Always reads back ‘0’
Note 1:
Changing the SRCLK bits while the SR latch is enabled may cause false triggers to the set and Reset
inputs of the latch.
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PIC18(L)F1XK22
REGISTER 19-2:
SRCON1: SR LATCH CONTROL REGISTER 1
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
SRSPE
SRSCKE
SRSC2E
SRSC1E
SRRPE
SRRCKE
SRRC2E
SRRC1E
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented
C = Clearable only bit
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
SRSPE: SR Latch Peripheral Set Enable bit
1 = INT1 pin status sets SR latch
0 = INT1 pin status has no effect on SR latch
bit 6
SRSCKE: SR Latch Set Clock Enable bit
1 = Set input of SR latch is pulsed with SRCLK
0 = Set input of SR latch is not pulsed with SRCLK
bit 5
SRSC2E: SR Latch C2 Set Enable bit
1 = C2 Comparator output sets SR latch
0 = C2 Comparator output has no effect on SR latch
bit 4
SRSC1E: SR Latch C1 Set Enable bit
1 = C1 Comparator output sets SR latch
0 = C1 Comparator output has no effect on SR latch
bit 3
SRRPE: SR Latch Peripheral Reset Enable bit
1 = INT1 pin resets SR latch
0 = INT1 pin has no effect on SR latch
bit 2
SRRCKE: SR Latch Reset Clock Enable bit
1 = Reset input of SR latch is pulsed with SRCLK
0 = Reset input of SR latch is not pulsed with SRCLK
bit 1
SRRC2E: SR Latch C2 Reset Enable bit
1 = C2 Comparator output resets SR latch
0 = C2 Comparator output has no effect on SR latch
bit 0
SRRC1E: SR Latch C1 Reset Enable bit
1 = C1 Comparator output resets SR latch
0 = C1 Comparator output has no effect on SR latch
TABLE 19-2:
Name
CM2CON1
INTCON3
REGISTERS ASSOCIATED WITH THE SR LATCH
Bit 7
Bit 6
MC1OUT MC2OUT
INT2IP
INT1IP
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
C1RSEL
C2RSEL
C1HYS
C2HYS
C1SYNC
C2SYNC
248
—
INT2IE
INT1IE
—
INT2IF
INT1IF
245
SRCON0
SRLEN
SRCLK2
SRCLK1
SRCLK0
SRQEN
SRNQEN
SRPS
SRPR
248
SRCON1
SRSPE
SRSCKE
SRSC2E SRSC1E
SRRPE
SRRCKE
SRRC2E
SRRC1E
248
TRISC
TRISC7
TRISC6
TRISC5
TRISC3
TRISC2
TRISC1
TRISC0
248
TRISC4
Legend: Shaded cells are not used with the SR Latch module.
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PIC18(L)F1XK22
20.0
FIXED VOLTAGE REFERENCE
(FVR)
20.1
The Fixed Voltage Reference, or FVR, is a stable
voltage reference, independent of VDD, with 1.024V,
2.048V or 4.096V selectable output levels. The output
of the FVR can be configured to supply a reference
voltage to the following:
•
•
•
•
ADC input channel
ADC positive reference
Comparator positive input
Digital-to-Analog Converter (DAC)
The FVR can be enabled by setting the FVR1EN bit of
the VREFCON0 register.
Independent Gain Amplifiers
The output of the FVR supplied to the ADC,
Comparators and DAC is routed through an
independent programmable gain amplifier. The
amplifier can be configured to amplify the 1.024V
reference voltage by 1x, 2x or 4x, to produce the three
possible voltage levels.
The FVR1S bits of the VREFCON0 register are
used to enable and configure the gain amplifier settings
for the reference supplied to the DAC and Comparator
modules. When the ADC module is configured to use
the FVR output, (FVR1BUF2) the reference is buffered
through an additional unity gain amplifier. This buffer is
disabled if the ADC is not configured to use the FVR.
For specific use of the FVR, refer to the specific module
sections: Section 16.0 “Analog-to-Digital Converter
(ADC) Module”, Section 21.0 “Digital-to-Analog
Converter (DAC) Module” and Section 17.0 “Comparator Module”.
20.2
FVR Stabilization Period
When the Fixed Voltage Reference module is enabled, it
requires time for the reference and amplifier circuits to
stabilize. Once the circuits stabilize and are ready for use,
the FVR1ST bit of the VREFCON0 register will be set.
See Table 26-23 for the minimum delay requirement.
FIGURE 20-1:
VOLTAGE REFERENCE BLOCK DIAGRAM
FVR_buf2_enable(1)
x1
x2
x4
FVR1S
FVR1BUF2
to ADC module
2
x1
x2
x4
FVR1BUF1
to Comparators, DAC
1.024V
FVR1EN
+
Fixed
Voltage
Reference
FVR1ST
Note 1: FVR_buf2_enable = ‘1’ when (ADON = ‘1’)AND [(PVCFG = ‘10’) OR ( CHS = ‘11111’)]
2009-2016 Microchip Technology Inc.
DS40001365F-page 231
PIC18(L)F1XK22
20.3
Register Definitions: FVR Control
REGISTER 20-1:
VREFCON0: FIXED VOLTAGE REFERENCE CONTROL REGISTER
R/W-0
R/W-0
FVR1EN
FVR1ST
R/W-0
R/W-1
U-0
U-0
U-0
U-0
—
—
—
—
FVR1S
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
u = Bit is unchanged
x = Bit is unknown
-n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
FVR1EN: Fixed Voltage Reference Enable bit
0 = Fixed Voltage Reference is disabled
1 = Fixed Voltage Reference is enabled
bit 6
FVR1ST: Fixed Voltage Reference Ready Flag bit
0 = Fixed Voltage Reference output is not ready or not enabled
1 = Fixed Voltage Reference output is ready for use
bit 5-4
FVR1S: Fixed Voltage Reference Selection bits
00 = Fixed Voltage Reference Peripheral output is off
01 = Fixed Voltage Reference Peripheral output is 1x (1.024V)
10 = Fixed Voltage Reference Peripheral output is 2x (2.048V)(1)
11 = Fixed Voltage Reference Peripheral output is 4x (4.096V)(1)
bit 3-2
Reserved: Read as ‘0’. Maintain these bits clear.
bit 1-0
Unimplemented: Read as ‘0’.
Note 1: Fixed Voltage Reference output cannot exceed VDD.
TABLE 20-1:
Name
VREFCON0
Legend:
SUMMARY OF REGISTERS ASSOCIATED WITH FIXED VOLTAGE REFERENCE
Bit 7
Bit 6
FVR1EN
FVR1ST
Bit 5
Bit 4
FVR1S
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values on
Page
—
—
—
—
232
— = unimplemented locations, read as ‘0’. Shaded bits are not used by the FVR module.
DS40001365F-page 232
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
21.0
DIGITAL-TO-ANALOG
CONVERTER (DAC) MODULE
The Digital-to-Analog Converter supplies a variable
voltage reference, ratiometric with the input source,
with 32 selectable output levels.
The negative voltage source is disabled by setting the
D1LPS bit in the VREFCON1 register. Clearing the
D1LPS bit in the VREFCON1 register disables the
positive voltage source.
21.4
The input of the DAC can be connected to:
Output Clamped to Positive
Voltage Source
• External VREF pins
• VDD supply voltage
• FVR (Fixed Voltage Reference)
The DAC output voltage can be set to VSRC+ with the
least amount of power consumption by performing the
following:
The output of the DAC can be configured to supply a
reference voltage to the following:
• Clearing the D1EN bit in the VREFCON1 register.
• Setting the D1LPS bit in the VREFCON1 register.
• Configuring the D1PSS bits to the proper positive
source.
• Configuring the DAC1Rx bits to ‘11111’ in the
VREFCON2 register.
• Comparator positive input
• ADC input channel
• DAC1OUT pin
The Digital-to-Analog Converter (DAC) can be enabled
by setting the D1EN bit of the VREFCON1 register.
21.1
Output Voltage Selection
The DAC has 32 voltage level ranges. The 32 levels
are set with the DAC1R bits of the VREFCON2
register.
The DAC output voltage is determined by the following
equations:
EQUATION 21-1:
DAC OUTPUT VOLTAGE
DACR
VOUT = VSRC+ – VSRC- ------------------------------- + VSRC5
2
VSRC+ = VDD, VREF+ or FVR1
VSRC- = VSS or VREF-
21.2
Ratiometric Output Level
The DAC output value is derived using a resistor ladder
with each end of the ladder tied to a positive and
negative voltage reference input source. If the voltage
of either input source fluctuates, a similar fluctuation will
result in the DAC output value.
The value of the individual resistors within the ladder
can be found in Section 26.0 “Electrical
Specifications”.
21.3
Low-Power Voltage State
In order for the DAC module to consume the least
amount of power, one of the two voltage reference input
sources to the resistor ladder must be disconnected.
Either the positive voltage source, (VSRC+), or the
negative voltage source, (VSRC-) can be disabled.
2009-2016 Microchip Technology Inc.
This is also the method used to output the voltage level
from the FVR to an output pin. See Section 21.6 “DAC
Voltage Reference Output” for more information.
21.5
Output Clamped to Negative
Voltage Source
The DAC output voltage can be set to VSRC- with the
least amount of power consumption by performing the
following:
• Clearing the D1EN bit in the VREFCON1 register.
• Clearing the DAC1R bit in the VREFCON1 register.
• Configuring the D1PSS bits to the proper negative
source.
• Configuring the DAC1Rx bits to ‘00000’ in the
VREFCON2 register.
This allows the comparator to detect a zero-crossing
while not consuming additional current through the DAC
module.
21.6
DAC Voltage Reference Output
The DAC can be output to the DAC1OUT (CVREF) pin by
setting the DAC1OE bit of the VREFCON1 register to ‘1’.
Selecting the DAC reference voltage for output on the
DAC1OUT pin automatically overrides the digital output
buffer and digital input threshold detector functions of
that pin. Reading the DAC1OUT pin when it has been
configured for DAC reference voltage output will always
return a ‘0’.
Due to the limited current drive capability, a buffer must
be used on the DAC voltage reference output for
external connections to DAC1OUT. Figure 21-2 shows
an example buffering technique.
DS40001365F-page 233
PIC18(L)F1XK22
FIGURE 21-1:
DIGITAL-TO-ANALOG CONVERTER BLOCK DIAGRAM
Digital-to-Analog Converter (DAC)
Reserved
11
10
FVR1BUF1
VREF+
VSRC+
01
00
VDD
DAC1R
5
R
2
R
D1PSS
R
D1EN
D1LPS
11111
11110
R
32
Steps
R
32-to-1 MUX
R
DAC Output
(to Comparators and
ADC Modules)
R
R
00001
CVREF/DAC1OUT
00000
DAC1OE
D1NSS
FIGURE 21-2:
VREF-
1
VSS
0
VSRC-
VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE
PIC® MCU
DAC
Module
R
Voltage
Reference
Output
Impedance
DS40001365F-page 234
DAC1OUT
+
–
Buffered DAC Output
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
21.7
Operation During Sleep
21.8
When the device wakes up from Sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the VREFCON1 register are not affected. To minimize
current consumption in Sleep mode, the voltage
reference should be disabled.
21.9
Effects of a Reset
A device Reset affects the following:
• DAC is disabled
• DAC output voltage is removed from the
DAC1OUT pin
• The DAC1R range select bits are cleared
Register Definitions: DAC Control
REGISTER 21-1:
VREFCON1: VOLTAGE REFERENCE CONTROL REGISTER 0
R/W-0
R/W-0
R/W-0
U-0
D1EN
D1LPS
DAC1OE
—
R/W-0
R/W-0
U-0
R/W-0
—
D1NSS
D1PSS
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
u = Bit is unchanged
x = Bit is unknown
-n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
D1EN: DAC Enable bit
1 = DAC is enabled
0 = DAC is disabled
bit 6
D1LPS: DAC Low-Power Voltage Source Select bit
1 = DAC Positive reference source selected
0 = DAC Negative reference source selected
bit 5
DAC1OE: DAC Voltage Output Enable bit
1 = DAC voltage level is also an output on the DAC1OUT (CVREF) pin
0 = DAC voltage level is disconnected from the DAC1OUT (CVREF) pin
bit 4
Unimplemented: Read as ‘0’
bit 3-2
D1PSS: DAC Positive Source Select bits
00 = VDD
01 = VREF+
10 = FVR1BUF1 output
11 = Reserved, do not use
bit 1
Unimplemented: Read as ‘0’
bit 0
D1NSS: DAC Negative Source Select bits
1 = VREF0 = VSS
2009-2016 Microchip Technology Inc.
DS40001365F-page 235
PIC18(L)F1XK22
REGISTER 21-2:
VREFCON2: VOLTAGE REFERENCE CONTROL REGISTER 1
U-0
U-0
U-0
—
—
—
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
DAC1R
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
u = Bit is unchanged
x = Bit is unknown
-n/n = Value at POR and BOR/Value at all other Resets
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7-5
Unimplemented: Read as ‘0’
bit 4-0
DAC1R: DAC Voltage Output Select bits
VOUT = ((VSRC+) - (VSRC-))*(DAC1R/(25)) + VSRC-
TABLE 21-1:
Name
REGISTERS ASSOCIATED WITH DAC MODULE
Bit 7
Bit 6
Bit 5
VREFCON0
FVR1EN
FVR1ST
VREFCON1
D1EN
D1LPS
DAC1OE
VREFCON2
—
—
—
Legend:
Bit 4
FVR1S
—
Bit 0
Reset
Values on
Page
—
—
232
—
D1NSS
Bit 3
Bit 2
Bit 1
—
—
D1PSS
DAC1R
235
236
— = Unimplemented locations, read as ‘0’. Shaded bits are not used by the DAC module.
DS40001365F-page 236
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
22.0
RESET
The PIC18(L)F1XK22 devices differentiate between
various kinds of Reset:
a)
b)
c)
d)
e)
f)
g)
h)
Power-on Reset (POR)
MCLR Reset during normal operation
MCLR Reset during power-managed modes
Watchdog Timer (WDT) Reset (during
execution)
Programmable Brown-out Reset (BOR)
RESET Instruction
Stack Full Reset
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 3.1.2.4 “Stack Overflow and Underflow
Resets”. WDT Resets are covered in Section 23.2
“Watchdog Timer (WDT)”.
FIGURE 22-1:
A simplified block diagram of the On-Chip Reset Circuit
is shown in Figure 22-1.
22.1
RCON Register
Device Reset events are tracked through the RCON
register (Register 22-1). 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 22.6 “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 7.0 “Interrupts”. BOR is covered in
Section 22.4 “Brown-out Reset (BOR)”.
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
RESET
Instruction
Stack Full/Underflow Reset
Stack
Pointer
External Reset
MCLRE
MCLR
( )_IDLE
Sleep
WDT
Time-out
VDD Rise
Detect
POR Pulse
VDD
Brown-out
Reset
BOREN
S
OST/PWRT
OST(2) 1024 Cycles
10-bit Ripple Counter
OSC1
32 s
LFINTOSC
Chip_Reset
R
Q
PWRT(2) 65.5 ms
11-bit Ripple Counter
Enable PWRT
Enable OST(1)
Note 1:
2:
See Table 22-2 for time-out situations.
PWRT and OST counters are reset by POR and BOR. See Sections 22.3 and 22.4.
2009-2016 Microchip Technology Inc.
DS40001365F-page 237
PIC18(L)F1XK22
REGISTER 22-1:
RCON: RESET CONTROL REGISTER
R/W-0
R/W-1
U-0
R/W-1
R-1
R-1
R/W-0
R/W-0
IPEN
SBOREN(1)
—
RI
TO
PD
POR(2)
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 BOREN = 01:
1 = BOR is enabled
0 = BOR is disabled
If BOREN = 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 or Power-on Reset)
0 = The RESET instruction was executed causing a device Reset (must be set in firmware after a
code-executed 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 = No Power-on Reset occurred
0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)
bit 0
BOR: Brown-out Reset Status bit(3)
1 = A Brown-out Reset has not occurred (set by firmware only)
0 = A Brown-out Reset occurred (must be set by firmware after a POR or Brown-out Reset occurs)
Note 1:
2:
3:
If SBOREN is enabled, its Reset state is ‘1’; otherwise, it is ‘0’.
The actual Reset value of POR is determined by the type of device Reset. See the notes following this
register and Section 22.6 “Reset State of Registers” for additional information.
See Table 22-3.
DS40001365F-page 238
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
22.2
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.
FIGURE 22-2:
In PIC18(L)F1XK22 devices, the MCLR input can be
disabled with the MCLRE Configuration bit. When
MCLR is disabled, the pin becomes a digital input. See
Section 8.1 “PORTA, TRISA and LATA Registers”
for more information.
22.3
D
To take advantage of the POR circuitry, tie the MCLR
pin through a resistor (1 k to 10 k) to VDD. This will
eliminate external RC components usually needed to
create a Power-on Reset delay.
PIC® MCU
R
R1
MCLR
C
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 k is recommended to make sure that
the voltage drop across R does not violate
the device’s electrical specification.
3:
R1 1 k 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).
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.
VDD
VDD
The MCLR pin is not driven low by any internal Resets,
including the WDT.
EXTERNAL POWER-ON
RESET CIRCUIT (FOR
SLOW VDD POWER-UP)
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.
POR events are captured by the POR bit of the RCON
register. The state of the bit is set to ‘0’ whenever a
POR occurs; it does not change for any other Reset
event. POR is not reset to ‘1’ by any hardware event.
To capture multiple events, the user must manually set
the bit to ‘1’ by software following any POR.
2009-2016 Microchip Technology Inc.
DS40001365F-page 239
PIC18(L)F1XK22
22.4
Brown-out Reset (BOR)
PIC18(L)F1XK22 devices implement a BOR circuit that
provides the user with a number of configuration and
power-saving options. The BOR is controlled by the
BORV and BOREN bits of the CONFIG2L
Configuration register. There are a total of four BOR
configurations which are summarized in Table 22-1.
The BOR threshold is set by the BORV bits. If
BOR is enabled (any values of BOREN, except
‘00’), any drop of VDD below VBOR for greater than
TBOR 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. 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 BOR Reset does
not automatically enable the PWRT.
22.4.1
SOFTWARE ENABLED BOR
When BOREN = 01, the BOR can be enabled or
disabled by the user in software. This is done with the
SBOREN control bit of the RCON register. 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’.
TABLE 22-1:
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.
Note:
22.4.2
Even when BOR is under software
control, the BOR Reset voltage level is still
set by the BORV Configuration bits.
It cannot be changed by software.
DETECTING BOR
When BOR is enabled, the BOR bit always resets to ‘0’
on any BOR or POR event. This makes it difficult to
determine if a BOR 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 and BOR bits are reset to
‘1’ by software immediately after any POR event. If
BOR is ‘0’ while POR is ‘1’, it can be reliably assumed
that a BOR event has occurred.
22.4.3
DISABLING BOR IN SLEEP MODE
When BOREN = 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.
BOR CONFIGURATIONS
BOR Configuration
BOREN1
BOREN0
Status of
SBOREN
(RCON)
0
0
Unavailable
0
1
Available
1
0
Unavailable
BOR enabled by hardware in Run and Idle modes, disabled during
Sleep mode.
1
1
Unavailable
BOR enabled by hardware; must be disabled by reprogramming the
Configuration bits.
DS40001365F-page 240
BOR Operation
BOR disabled; must be enabled by reprogramming the Configuration bits.
BOR enabled by software; operation controlled by SBOREN.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
22.5
Device Reset Timers
PIC18(L)F1XK22 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
22.5.1
POWER-UP TIMER (PWRT)
The Power-up Timer (PWRT) of PIC18(L)F1XK22
devices is an 11-bit counter which uses the
LFINTOSC source as the clock input. This yields an
approximate time interval of 2048 x 32 s = 65.6 ms.
While the PWRT is counting, the device is held in
Reset.
The power-up time delay depends on the LFINTOSC
clock and will vary from chip-to-chip due to temperature
and process variation. See Section 26.0 “Electrical
Specifications” for details.
The PWRT is enabled by clearing the PWRTEN
Configuration bit.
22.5.2
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. This ensures that the crystal
oscillator or resonator has started and stabilized.
TABLE 22-2:
22.5.3
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.
22.5.4
TIME-OUT SEQUENCE
On power-up, the time-out sequence is as follows:
1.
2.
After the POR pulse has cleared, PWRT time-out
is invoked (if enabled).
Then, the OST is activated.
The total time-out will vary based on oscillator
configuration and the status of the PWRT. Figure 22-3,
Figure 22-4, Figure 22-5, Figure 22-6 and Figure 22-7
all depict time-out sequences on power-up, with the
Power-up Timer enabled and the device operating in
HS Oscillator mode. Figures 22-3 through 22-6 also
apply to devices operating in XT or LP modes. For
devices in RC mode and with the PWRT disabled, on
the other hand, 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, after
which, bringing MCLR high will allow program
execution to begin immediately (Figure 22-5). This is
useful for testing purposes or to synchronize more than
one PIC18(L)F1XK22 device operating in parallel.
TIME-OUT IN VARIOUS SITUATIONS
Power-up(2) and Brown-out
Oscillator
Configuration
HSPLL
The OST time-out is invoked only for XT, LP, HS and
HSPLL modes and only on Power-on Reset, or on exit
from all power-managed modes that stop the external
oscillator.
PWRTEN = 0
66
ms(1)
+ 1024 TOSC + 2
ms(2)
PWRTEN = 1
Exit from
Power-Managed Mode
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
ms(1)
—
—
(1)
—
—
INTIO1, INTIO2
66
66 ms
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.
2009-2016 Microchip Technology Inc.
DS40001365F-page 241
PIC18(L)F1XK22
FIGURE 22-3:
TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1
FIGURE 22-4:
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2
FIGURE 22-5:
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
DS40001365F-page 242
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 22-6:
SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT)
5V
VDD
0V
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 22-7:
TIME-OUT SEQUENCE ON POR W/PLL ENABLED (MCLR TIED TO VDD)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
OST TIME-OUT
TOST
TPLL
PLL TIME-OUT
INTERNAL RESET
Note:
TOST = 1024 clock cycles.
TPLL 2 ms max. First three stages of the PWRT timer.
2009-2016 Microchip Technology Inc.
DS40001365F-page 243
PIC18(L)F1XK22
22.6
Reset State of Registers
Some registers are unaffected by a Reset. Their status
is unknown on POR and unchanged by all other
Resets. All other registers are forced to a “Reset state”
depending on the type of Reset that occurred.
Most registers are not affected by a WDT wake-up,
since this is viewed as the resumption of normal
operation. Status bits from the RCON register, RI, TO,
PD, POR and BOR, are set or cleared differently in
different Reset situations, as indicated in Table 22-3.
These bits are used by software to determine the
nature of the Reset.
Table 22-4 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 22-3:
STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION
FOR RCON REGISTER
Condition
Program
Counter
RCON Register
SBOREN
RI
TO
PD
STKPTR Register
POR BOR STKOVF
STKUNF
Power-on Reset
0000h
1
1
1
1
0
0
0
0
RESET Instruction
0000h
u(2)
0
u
u
u
u
u
u
Brown-out Reset
0000h
(2)
u
1
1
1
u
0
u
u
MCLR during Power-Managed
Run Modes
0000h
u(2)
u
1
u
u
u
u
u
MCLR during Power-Managed
Idle Modes and Sleep Mode
0000h
u(2)
u
1
0
u
u
u
u
WDT Time-out during Full Power
or Power-Managed Run Mode
0000h
u(2)
u
0
u
u
u
u
u
MCLR during Full Power
Execution
0000h
u(2)
u
u
u
u
u
u
u
Stack Full Reset (STVREN = 1)
0000h
u(2)
u
u
u
u
u
1
u
Stack Underflow Reset
(STVREN = 1)
0000h
u(2)
u
u
u
u
u
u
1
Stack Underflow Error (not an
actual Reset, STVREN = 0)
0000h
u(2)
u
u
u
u
u
u
1
WDT Time-out during
Power-Managed Idle or Sleep
Modes
PC + 2
u(2)
u
0
0
u
u
u
u
PC + 2(1)
u(2)
u
u
0
u
u
u
u
Interrupt Exit from
Power-Managed Modes
Legend: u = unchanged
Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bits are 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
(BOREN Configuration bits = 01 and SBOREN = 1). Otherwise, the Reset state is ‘0’.
DS40001365F-page 244
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 22-4:
INITIALIZATION CONDITIONS FOR ALL REGISTERS
Address
Power-on Reset,
Brown-out Reset
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets
TOSU
FFFh
---0 0000
---0 0000
---0 uuuu(3)
TOSH
FFEh
0000 0000
0000 0000
uuuu uuuu(3)
TOSL
FFDh
0000 0000
0000 0000
uuuu uuuu(3)
STKPTR
FFCh
00-0 0000
uu-0 0000
uu-u uuuu(3)
PCLATU
FFBh
---0 0000
---0 0000
---u uuuu
PCLATH
FFAh
0000 0000
0000 0000
uuuu uuuu
PCL
FF9h
0000 0000
0000 0000
TBLPTRU
FF8h
---0 0000
---0 0000
---u uuuu
TBLPTRH
FF7h
0000 0000
0000 0000
uuuu uuuu
TBLPTRL
FF6h
0000 0000
0000 0000
uuuu uuuu
TABLAT
FF5h
0000 0000
0000 0000
uuuu uuuu
PRODH
FF4h
xxxx xxxx
uuuu uuuu
uuuu uuuu
PRODL
FF3h
xxxx xxxx
uuuu uuuu
uuuu uuuu
INTCON
FF2h
0000 000x
0000 000u
uuuu uuuu(1)
INTCON2
FF1h
1111 -1-1
1111 -1-1
uuuu -u-u(1)
INTCON3
FF0h
11-0 0-00
11-0 0-00
uu-u u-uu(1)
INDF0
FEFh
N/A
N/A
N/A
POSTINC0
FEEh
N/A
N/A
N/A
POSTDEC0
FEDh
N/A
N/A
N/A
PREINC0
Register
Wake-up via WDT
or Interrupt
PC + 2(2)
FECh
N/A
N/A
N/A
PLUSW0
FEBh
N/A
N/A
N/A
FSR0H
FEAh
---- 0000
---- 0000
---- uuuu
FSR0L
FE9h
xxxx xxxx
uuuu uuuu
uuuu uuuu
WREG
FE8h
xxxx xxxx
uuuu uuuu
uuuu uuuu
INDF1
FE7h
N/A
N/A
N/A
POSTINC1
FE6h
N/A
N/A
N/A
POSTDEC1
FE5h
N/A
N/A
N/A
PREINC1
FE4h
N/A
N/A
N/A
PLUSW1
FE3h
N/A
N/A
N/A
Legend:
Note 1:
2:
3:
4:
u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
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).
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.
See Table 22-3 for Reset value for specific condition.
2009-2016 Microchip Technology Inc.
DS40001365F-page 245
PIC18(L)F1XK22
TABLE 22-4:
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Address
Power-on Reset,
Brown-out Reset
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets
Wake-up via WDT
or Interrupt
FSR1H
FE2h
---- 0000
---- 0000
---- uuuu
FSR1L
FE1h
xxxx xxxx
uuuu uuuu
uuuu uuuu
BSR
FE0h
---- 0000
---- 0000
---- uuuu
INDF2
FDFh
N/A
N/A
N/A
POSTINC2
FDEh
N/A
N/A
N/A
POSTDEC2
FDDh
N/A
N/A
N/A
PREINC2
FDCh
N/A
N/A
N/A
PLUSW2
FDBh
N/A
N/A
N/A
FSR2H
FDAh
---- 0000
---- 0000
---- uuuu
FSR2L
FD9h
xxxx xxxx
uuuu uuuu
uuuu uuuu
STATUS
FD8h
---x xxxx
---u uuuu
---u uuuu
TMR0H
FD7h
0000 0000
0000 0000
uuuu uuuu
TMR0L
FD6h
xxxx xxxx
uuuu uuuu
uuuu uuuu
T0CON
FD5h
1111 1111
1111 1111
uuuu uuuu
OSCCON
FD3h
0011 qq00
0011 qq00
uuuu uuuu
OSCCON2
FD2h
---- -10x
---- -10x
---- -uuu
WDTCON
FD1h
---- ---0
---- ---0
---- ---u
RCON(4)
FD0h
0q-1 11q0
0q-q qquu
uq-u qquu
TMR1H
FCFh
xxxx xxxx
uuuu uuuu
uuuu uuuu
TMR1L
FCEh
xxxx xxxx
uuuu uuuu
uuuu uuuu
T1CON
FCDh
0000 0000
u0uu uuuu
uuuu uuuu
TMR2
FCCh
0000 0000
0000 0000
uuuu uuuu
PR2
FCBh
1111 1111
1111 1111
1111 1111
T2CON
FCAh
-000 0000
-000 0000
-uuu uuuu
SSPBUF
FC9h
xxxx xxxx
uuuu uuuu
uuuu uuuu
SSPADD
FC8h
0000 0000
0000 0000
uuuu uuuu
SSPSTAT
FC7h
0000 0000
0000 0000
uuuu uuuu
SSPCON1
FC6h
0000 0000
0000 0000
uuuu uuuu
SSPCON2
FC5h
0000 0000
0000 0000
uuuu uuuu
Register
Legend:
Note 1:
2:
3:
4:
u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
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).
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.
See Table 22-3 for Reset value for specific condition.
DS40001365F-page 246
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 22-4:
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Address
Power-on Reset,
Brown-out Reset
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets
Wake-up via WDT
or Interrupt
ADRESH
FC4h
xxxx xxxx
uuuu uuuu
uuuu uuuu
ADRESL
FC3h
xxxx xxxx
uuuu uuuu
uuuu uuuu
ADCON0
FC2h
--00 0000
--00 0000
--uu uuuu
ADCON1
FC1h
---- 0000
---- 0000
---- uuuu
ADCON2
FC0h
0-00 0000
0-00 0000
u-uu uuuu
CCPR1H
FBFh
xxxx xxxx
uuuu uuuu
uuuu uuuu
CCPR1L
FBEh
xxxx xxxx
uuuu uuuu
uuuu uuuu
CCP1CON
FBDh
0000 0000
0000 0000
uuuu uuuu
VREFCON2
FBCh
---0 0000
---0 0000
---u uuuu
VREFCON1
FBBh
000- 00-0
000- 00-0
uuu- uu-u
VREFCON0
FBAh
0001 ----
0001 ----
uuuu ----
PSTRCON
FB9h
---0 0001
---0 0001
---u uuuu
BAUDCON
FB8h
0100 0-00
0100 0-00
uuuu u-uu
PWM1CON
FB7h
0000 0000
0000 0000
uuuu uuuu
ECCP1AS
FB6h
0000 0000
0000 0000
uuuu uuuu
TMR3H
FB3h
xxxx xxxx
uuuu uuuu
uuuu uuuu
TMR3L
FB2h
xxxx xxxx
uuuu uuuu
uuuu uuuu
T3CON
FB1h
0-00 0000
u-uu uuuu
u-uu uuuu
SPBRGH
FB0h
0000 0000
0000 0000
uuuu uuuu
SPBRG
FAFh
0000 0000
0000 0000
uuuu uuuu
RCREG
FAEh
0000 0000
0000 0000
uuuu uuuu
TXREG
FADh
0000 0000
0000 0000
uuuu uuuu
TXSTA
FACh
0000 0010
0000 0010
uuuu uuuu
RCSTA
FABh
0000 000x
0000 000x
uuuu uuuu
EEADR
FAAh
0000 0000
0000 0000
uuuu uuuu
EEDATA
FA8h
0000 0000
0000 0000
uuuu uuuu
EECON2
FA7h
0000 0000
0000 0000
0000 0000
EECON1
FA6h
xx-0 x000
uu-0 u000
uu-0 u000
Register
Legend:
Note 1:
2:
3:
4:
u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
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).
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.
See Table 22-3 for Reset value for specific condition.
2009-2016 Microchip Technology Inc.
DS40001365F-page 247
PIC18(L)F1XK22
TABLE 22-4:
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Address
Power-on Reset,
Brown-out Reset
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets
Wake-up via WDT
or Interrupt
IPR2
FA2h
1111 1-1-
1111 1-1-
uuuu u-u-
PIR2
FA1h
0000 0-0-
0000 0-0-
uuuu u-u-(1)
PIE2
FA0h
0000 0-0-
0000 0-0-
uuuu u-u-
IPR1
F9Fh
-111 1111
-111 1111
-uuu uuuu
PIR1
F9Eh
-000 0000
-000 0000
-uuu uuuu(1)
PIE1
F9Dh
-000 0000
-000 0000
-uuu uuuu
OSCTUNE
F9Bh
0000 0000
0000 0000
uuuu uuuu
TRISC
F95h
1111 1111
1111 1111
uuuu uuuu
TRISB
F94h
1111 ----
1111 ----
uuuu ----
TRISA
F93h
LATC
F8Bh
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATB
F8Ah
xxxx ----
uuuu ----
uuuu ----
LATA
F89h
PORTC
F82h
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTB
F81h
xxxx ----
uuuu ----
uuuu ----
PORTA
F80h
ANSELH
F7Fh
---- 1111
---- 1111
---- uuuu
ANSEL
F7Eh
1111 1111
1111 1111
uuuu uuuu
IOCB
F7Ah
0000 ----
0000 ----
uuuu ----
IOCA
F79h
--00 0000
--00 0000
--uu uuuu
WPUB
F78h
1111 ----
1111 ----
uuuu ----
WPUA
F77h
--11 1111
--11 1111
--uu uuuu
SLRCON
F76h
---- -111
---- -111
---- -uuu
SSPMSK
F6Fh
1111 1111
1111 1111
uuuu uuuu
CM1CON0
F6Dh
0000 0000
0000 0000
uuuu uuuu
CM2CON1
F6Ch
0000 0000
0000 0000
uuuu uuuu
CM2CON0
F6Bh
0000 0000
0000 0000
uuuu uuuu
SRCON1
F69h
0000 0000
0000 0000
uuuu uuuu
SRCON0
F68h
0000 0000
0000 0000
uuuu uuuu
Register
Legend:
Note 1:
2:
3:
4:
--11 1111
--xx xxxx
--xx xxxx
--11 1111
--uu uuuu
--xx xxxx
--uu uuuu
--uu uuuu
--uu uuuu
u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
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).
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.
See Table 22-3 for Reset value for specific condition.
DS40001365F-page 248
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
23.0
SPECIAL FEATURES OF
THE CPU
PIC18(L)F1XK22 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)
• 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 Module”.
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, PIC18(L)F1XK22 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. TwoSpeed 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.
2009-2016 Microchip Technology Inc.
DS40001365F-page 249
PIC18(L)F1XK22
23.1
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 the 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 4.5 “Writing
to Flash Program Memory”.
TABLE 23-1:
CONFIGURATION BITS AND DEVICE IDs
File Name
Bit 7
Bit 6
Bit 5
Bit 4
300001h CONFIG1H
IESO
FCMEN
PCLKEN
PLL_EN
FOSC3
FOSC2
300002h CONFIG2L
—
—
—
BORV1
BORV0
BOREN1
300003h CONFIG2H
—
—
—
WDTPS3
WDTPS2
—
—
—
HFOFST
—
300005h CONFIG3H MCLRE
300006h CONFIG4L
BKBUG ENHCPU
Bit 3
Bit 2
Bit 1
Bit 0
FOSC1
FOSC0
BOREN0 PWRTEN
WDTPS1 WDTPS0
Default/
Unprogrammed
Value
0010 0111
---1 1111
WDTEN
---1 1111
—
—
1--- 1---
—
—
BBSIZ
LVP
—
STVREN
-0-- 01-1
300008h CONFIG5L
—
—
—
—
—
—
CP1
CP0
---- --11
300009h CONFIG5H
CPD
CPB
—
—
—
—
—
—
11-- ----
30000Ah CONFIG6L
—
—
—
—
—
—
WRT1
WRT0
---- --11
111- ----
30000Bh CONFIG6H
WRTD
WRTB
WRTC
—
—
—
—
—
30000Ch CONFIG7L
—
—
—
—
—
—
EBTR1
EBTR0
---- --11
30000Dh CONFIG7H
—
EBTRB
—
—
—
—
—
—
-1-- ----
3FFFFEh DEVID1(1)
DEV2
DEV1
DEV0
REV4
REV3
REV2
REV1
REV0
qqqq qqqq(1)
3FFFFFh DEVID2(1)
DEV10
DEV9
DEV8
DEV7
DEV6
DEV5
DEV4
DEV3
0000 1100
Legend:
Note 1:
x = unknown, u = unchanged, – = unimplemented, q = value depends on condition.
Shaded cells are unimplemented, read as ‘0’
See Register 23-12 for DEVID1 values. DEVID registers are read-only and cannot be programmed by the user.
DS40001365F-page 250
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
REGISTER 23-1:
CONFIG1H: CONFIGURATION REGISTER 1 HIGH
R/P-0
R/P-0
R/P-1
R/P-0
R/P-0
R/P-1
R/P-1
R/P-1
IESO
FCMEN
PCLKEN
PLL_EN
FOSC3
FOSC2
FOSC1
FOSC0
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
x = Bit is unknown
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
PCLKEN: Primary Clock Enable bit
1 = Primary Clock enabled
0 = Primary Clock is under software control
bit 4
PLL_EN: 4 X PLL Enable bit
1 = Oscillator multiplied by 4
0 = PLL is under software control
bit 3-0
FOSC: Oscillator Selection bits
1111 = External RC oscillator, CLKOUT function on OSC2
1110 = External RC oscillator, CLKOUT function on OSC2
1101 = EC (low)
1100 = EC, CLKOUT function on OSC2 (low)
1011 = EC (medium)
1010 = EC, CLKOUT function on OSC2 (medium)
1001 = Internal RC oscillator, CLKOUT function on OSC2
1000 = Internal RC oscillator
0111 = External RC oscillator
0110 = External RC oscillator, CLKOUT function on OSC2
0101 = EC (high)
0100 = EC, CLKOUT function on OSC2 (high)
0011 = External RC oscillator, CLKOUT function on OSC2
0010 = HS oscillator
0001 = XT oscillator
0000 = LP oscillator
2009-2016 Microchip Technology Inc.
DS40001365F-page 251
PIC18(L)F1XK22
REGISTER 23-2:
U-0
CONFIG2L: CONFIGURATION REGISTER 2 LOW
U-0
—
—
U-0
—
R/P-1
BORV1
R/P-1
(1)
BORV0
(1)
R/P-1
BOREN1
R/P-1
(2)
BOREN0
bit 7
R/P-1
(2)
PWRTEN(2)
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
x = Bit is unknown
bit 7-5
Unimplemented: Read as ‘0’
bit 4-3
BORV: Brown-out Reset Voltage bits(1)
11 = VBOR set to 1.9V nominal
10 = VBOR set to 2.2V nominal
01 = VBOR set to 2.5V nominal
00 = VBOR set to 2.85V nominal
bit 2-1
BOREN: 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:
2:
See Table 26-1 for specifications.
The Power-up Timer is decoupled from Brown-out Reset, allowing these features to be independently
controlled.
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PIC18(L)F1XK22
REGISTER 23-3:
CONFIG2H: CONFIGURATION REGISTER 2 HIGH
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
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
x = Bit is unknown
bit 7-5
Unimplemented: Read as ‘0’
bit 4-1
WDTPS: 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 is always enabled. SWDTEN bit has no effect
0 = WDT is controlled by SWDTEN bit of the WDTCON register
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PIC18(L)F1XK22
REGISTER 23-4:
CONFIG3H: CONFIGURATION REGISTER 3 HIGH
R/P-1
U-0
U-0
U-0
R/P-1
U-0
U-0
U-0
MCLRE
—
—
—
HFOFST
—
—
—
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
x = Bit is unknown
bit 7
MCLRE: MCLR Pin Enable bit
1 = MCLR pin enabled; RA3 input pin disabled
0 = RA3 input pin enabled; MCLR disabled
bit 6-4
Unimplemented: Read as ‘0’
bit 3
HFOFST: HFINTOSC Fast Start-up bit
1 = HFINTOSC starts clocking the CPU without waiting for the oscillator to stabilize.
0 = The system clock is held off until the HFINTOSC is stable.
bit 2-0
Unimplemented: Read as ‘0’
REGISTER 23-5:
CONFIG4L: CONFIGURATION REGISTER 4 LOW
R/W-1(1)
R/W-0
U-0
U-0
R/P-0
R/P-1
U-0
R/P-1
BKBUG
ENHCPU
—
—
BBSIZ
LVP
—
STVREN
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
x = Bit is unknown
bit 7
BKBUG: Background Debugger Enable bit(1)
1 = Background Debugger disabled
0 = Background Debugger functions enabled
bit 6
ENHCPU: Enhanced CPU Enable bit
1 = Enhanced CPU enabled
0 = Enhanced CPU disabled
bit 5-4
Unimplemented: Read as ‘0’
bit 3
BBSIZ: Boot BLock Size Select bit
1 = 2 kW boot block size for PIC18(L)F14K22 (1 kW boot block size for
PIC18(L)F13K22)
0 = 1 kW boot block size for PIC18(L)F14K22 (512 W boot block size for
PIC18(L)F13K22)
bit 2
LVP: Single-Supply ICSP™ Enable bit
1 = Single-Supply ICSP enabled
0 = Single-Supply ICSP disabled
bit 1
Unimplemented: Read as ‘0’
bit 0
STVREN: Stack Full/Underflow Reset Enable bit
1 = Stack full/underflow will cause Reset
0 = Stack full/underflow will not cause Reset
Note 1:
BKBUG is only used for ICD device. Otherwise, this bit is unimplemented and reads as ‘1’.
DS40001365F-page 254
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PIC18(L)F1XK22
REGISTER 23-6:
CONFIG5L: CONFIGURATION REGISTER 5 LOW
U-0
U-0
U-0
U-0
U-0
U-0
R/C-1
R/C-1
—
—
—
—
—
—
CP1
CP0
bit 7
bit 0
Legend:
R = Readable bit
U = Unimplemented bit, read as ‘0’
-n = Value when device is unprogrammed
C = Clearable only bit
bit 7-2
Unimplemented: Read as ‘0’
bit 1
CP1: Code Protection bit
1 = Block 1 not code-protected
0 = Block 1 code-protected
bit 0
CP0: Code Protection bit
1 = Block 0 not code-protected
0 = Block 0 code-protected
REGISTER 23-7:
CONFIG5H: CONFIGURATION REGISTER 5 HIGH
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
U = Unimplemented bit, read as ‘0’
-n = Value when device is unprogrammed
C = Clearable only bit
bit 7
CPD: Data EEPROM Code Protection bit
1 = Data EEPROM not code-protected
0 = Data EEPROM code-protected
bit 6
CPB: Boot Block Code Protection bit
1 = Boot block not code-protected
0 = Boot block code-protected
bit 5-0
Unimplemented: Read as ‘0’
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DS40001365F-page 255
PIC18(L)F1XK22
REGISTER 23-8:
CONFIG6L: CONFIGURATION REGISTER 6 LOW
U-0
U-0
U-0
U-0
U-0
U-0
R/C-1
R/C-1
—
—
—
—
—
—
WRT1
WRT0
bit 7
bit 0
Legend:
R = Readable bit
U = Unimplemented bit, read as ‘0’
-n = Value when device is unprogrammed
C = Clearable only bit
bit 7-2
Unimplemented: Read as ‘0’
bit 1
WRT1: Write Protection bit
1 = Block 1 not write-protected
0 = Block 1 write-protected
bit 0
WRT0: Write Protection bit
1 = Block 0 not write-protected
0 = Block 0 write-protected
REGISTER 23-9:
R/C-1
WRTD
CONFIG6H: CONFIGURATION REGISTER 6 HIGH
R/C-1
R-1
U-0
U-0
U-0
U-0
U-0
WRTB
WRTC(1)
—
—
—
—
—
bit 7
bit 0
Legend:
R = Readable bit
U = Unimplemented bit, read as ‘0’
-n = Value when device is unprogrammed
C = Clearable only bit
bit 7
WRTD: Data EEPROM Write Protection bit
1 = Data EEPROM not write-protected
0 = Data EEPROM write-protected
bit 6
WRTB: Boot Block Write Protection bit
1 = Boot block not write-protected
0 = Boot block write-protected
bit 5
WRTC: Configuration Register Write Protection bit(1)
1 = Configuration registers not write-protected
0 = Configuration registers 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.
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PIC18(L)F1XK22
REGISTER 23-10: CONFIG7L: CONFIGURATION REGISTER 7 LOW
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
U = Unimplemented bit, read as ‘0’
-n = Value when device is unprogrammed
C = Clearable only bit
bit 7-2
Unimplemented: Read as ‘0’
bit 1
EBTR1: Table Read Protection bit
1 = Block 1 not protected from table reads executed in other blocks
0 = Block 1 protected from table reads executed in other blocks
bit 0
EBTR0: Table Read Protection bit
1 = Block 0 not protected from table reads executed in other blocks
0 = Block 0 protected from table reads executed in other blocks
REGISTER 23-11: CONFIG7H: CONFIGURATION REGISTER 7 HIGH
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
U = Unimplemented bit, read as ‘0’
-n = Value when device is unprogrammed
C = Clearable only bit
bit 7
Unimplemented: Read as ‘0’
bit 6
EBTRB: Boot Block Table Read Protection bit
1 = Boot block not protected from table reads executed in other blocks
0 = Boot block protected from table reads executed in other blocks
bit 5-0
Unimplemented: Read as ‘0’
2009-2016 Microchip Technology Inc.
DS40001365F-page 257
PIC18(L)F1XK22
REGISTER 23-12: DEVID1: DEVICE ID REGISTER 1 FOR PIC18(L)F1XK22
R
R
R
R
R
R
R
R
DEV2
DEV1
DEV0
REV4
REV3
REV2
REV1
REV0
bit 7
bit 0
Legend:
R = Readable bit
U = Unimplemented bit, read as ‘0’
-n = Value when device is unprogrammed
C = Clearable only bit
bit 7-5
DEV: Device ID bits
010 = PIC18(L)F13K22
011 = PIC18(L)F14K22
bit 4-0
REV: Revision ID bits
These bits are used to indicate the device revision.
REGISTER 23-13: DEVID2: DEVICE ID REGISTER 2 FOR PIC18(L)F1XK22
R
R
R
R
R
R
R
R
DEV10
DEV9
DEV8
DEV7
DEV6
DEV5
DEV4
DEV3
bit 7
bit 0
Legend:
R = Readable bit
U = Unimplemented bit, read as ‘0’
-n = Value when device is unprogrammed
C = Clearable only bit
bit 7-0
Note 1:
DEV: Device ID bits
These bits are used with the DEV bits in the Device ID Register 1 to identify the
part number.
0010 0000 = PIC18F13K22/PIC18F14K22 devices(1)
These values for DEV may be shared with other devices. The specific device is always identified
by using the entire DEV bit sequence.
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PIC18(L)F1XK22
23.2
Watchdog Timer (WDT)
For PIC18(L)F1XK22 devices, the WDT is driven by the
LFINTOSC 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 LFINTOSC
oscillator.
The 4-millisecond 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
Configuration 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 of the OSCCON register are changed or a
clock failure has occurred.
Note 1: The CLRWDT and SLEEP instructions
clear the WDT and postscaler counts
when executed.
2: Changing the setting of the IRCF bits of
the OSCCON register clears the WDT
and postscaler counts.
FIGURE 23-1:
WDT BLOCK DIAGRAM
SWDTEN
WDTEN
Enable WDT
WDT Counter
LFINTOSC Source
Wake-up
from Power
Managed Modes
128
Change on IRCF bits
Programmable Postscaler
1:1 to 1:32,768
CLRWDT
Reset
WDT
Reset
All Device Resets
WDTPS
4
Sleep
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DS40001365F-page 259
PIC18(L)F1XK22
23.2.1
CONTROL REGISTER
Register 23-14 shows the WDTCON register. This is a
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.
REGISTER 23-14: WDTCON: WATCHDOG TIMER CONTROL REGISTER
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
bit 7-1
Unimplemented: Read as ‘0’
bit 0
SWDTEN: Software Enable or Disable the Watchdog Timer bit(1)
1 = WDT is turned on
0 = WDT is turned off (Reset value)
x = Bit is unknown
Note 1: This bit has no effect if the Configuration bit, WDTEN, is enabled.
TABLE 23-2:
SUMMARY OF WATCHDOG TIMER REGISTERS
Bit 2
Bit 1
WDTEN
253
Bit 6
Bit 5
CONFIG2H
—
—
—
IPEN
SBOREN
—
RI
TO
PD
POR
BOR
246
—
—
—
—
—
—
—
SWDTEN
246
WDTCON
Bit 3
Reset
Values
on page
Bit 7
RCON
Bit 4
Bit 0
Name
WDTPS3 WDTPS2 WDTPS1 WDTPS0
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Watchdog Timer.
23.3
Program Verification and
Code Protection
The overall structure of the code protection on the
PIC18 Flash devices differs significantly from other PIC
microcontroller devices.
Figure 23-2 shows the program memory organization
for 8, 16 and 32-Kbyte devices and the specific code
protection bit associated with each block. The actual
locations of the bits are summarized in Table 23-3.
The user program memory is divided into five blocks.
One of these is a boot block of 0.5K or 2K bytes,
depending on the device. The remainder of the
memory is divided into individual blocks on binary
boundaries.
Each of the five blocks has three code protection bits
associated with them. They are:
• Code-Protect bit (CPn)
• Write-Protect bit (WRTn)
• External Block Table Read bit (EBTRn)
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PIC18(L)F1XK22
FIGURE 23-2:
CODE-PROTECTED PROGRAM MEMORY FOR PIC18(L)F1XK22
Device
Address (from/to)
14K22
BBSIZ = 1
0000h
03FFh
13K22
BBSIZ = 0
BBSIZ = 1
Boot Block, 4 KB
Boot Block, 2 KB
Boot Block, 2 KB
CPB, WRTB, EBTRB CPB, WRTB, EBTRB CPB, WRTB, EBTRB
0400h
07FFh
Block 0
6 KB
CP0, WRT0, EBTR0
0800h
0BFFh
0C00h
Block 0
2 KB
CP0, WRT0, EBTR0
BBSIZ = 0
Boot Block, 1 KB CPB,
WRTB, EBTRB
Block 0
1.512 KB
CP0, WRT0, EBTR0
0FFFh
1000h
1FFFh
Block 0
4 KB
CP0, WRT0, EBTR0
2000h
3FFFh
Block 1
8 KB
CP1, WRT1, EBTR1
Block 1
8 KB
CP1, WRT1, EBTR1
4000h
4FFEh
Reads all ‘0’s
Reads all ‘0’s
Block 1
4 KB
CP1, WRT1, EBTR1
Block 1
4 KB
CP1, WRT1, EBTR1
Reads all ‘0’s
Reads all ‘0’s
5000h
5FFEh
6000h
6FFEh
7000h
7FFEh
8000h
8FFEh
9000h
9FFEh
A000h
AFFEh
B000h
BFFEh
C000h
CFFEh
D000h
DFFEh
E000h
EFFEh
F000h
FFFEh
H000h
HFFEh
Note:
Refer to the test section for requirements on test memory mapping.
2009-2016 Microchip Technology Inc.
DS40001365F-page 261
PIC18(L)F1XK22
TABLE 23-3:
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
—
—
—
—
—
—
CP1
CP0
300009h
CONFIG5H
CPD
CPB
—
—
—
—
—
—
30000Ah
CONFIG6L
—
—
—
—
—
—
WRT1
WRT0
—
—
—
—
—
EBTR0
—
30000Bh
CONFIG6H
WRTD
WRTB
WRTC(1)
30000Ch
CONFIG7L
—
—
—
—
—
—
EBTR1
30000Dh
CONFIG7H
—
EBTRB
—
—
—
—
—
Legend: Shaded cells are unimplemented.
Note 1: Unimplemented in PIC18F13K22 and PIC18F14K22 devices; maintain this bit set.
23.3.1
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.
instruction that executes from a location outside of that
block is not allowed to read and will result in reading ‘0’s.
Figures 23-3 through 23-5 illustrate table write and table
read protection.
Note:
In normal execution mode, the CPn bits have no direct
effect. CPn bits inhibit external reads and writes. A block
of user memory may be protected from table writes if the
WRTn Configuration bit is ‘0’. The EBTRn bits control
table reads. For a block of user memory with the EBTRn
bit cleared to ‘0’, a table READ instruction that executes
from within that block is allowed to read. A table read
FIGURE 23-3:
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 or an external
programmer.
TABLE WRITE (WRTn) DISALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
0007FFh
000800h
TBLPTR = 0008FFh
PC = 001FFEh
WRTB, EBTRB = 11
WRT0, EBTR0 = 01
TBLWT*
001FFFh
002000h
WRT1, EBTR1 = 11
003FFFh
004000h
PC = 005FFEh
WRT2, EBTR2 = 11
TBLWT*
005FFFh
006000h
WRT3, EBTR3 = 11
007FFFh
Results: All table writes disabled to Blockn whenever WRTn = 0.
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PIC18(L)F1XK22
FIGURE 23-4:
EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
0007FFh
000800h
TBLPTR = 0008FFh
WRTB, EBTRB = 11
WRT0, EBTR0 = 10
001FFFh
002000h
PC = 003FFEh
WRT1, EBTR1 = 11
TBLRD*
003FFFh
004000h
WRT2, EBTR2 = 11
005FFFh
006000h
WRT3, EBTR3 = 11
007FFFh
Results: All table reads from external blocks to Blockn are disabled whenever EBTRn = 0.
TABLAT register returns a value of ‘0’.
FIGURE 23-5:
EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
0007FFh
000800h
TBLPTR = 0008FFh
PC = 001FFEh
WRTB, EBTRB = 11
WRT0, EBTR0 = 10
TBLRD*
001FFFh
002000h
WRT1, EBTR1 = 11
003FFFh
004000h
WRT2, EBTR2 = 11
005FFFh
006000h
WRT3, EBTR3 = 11
007FFFh
Results: Table reads permitted within Blockn, even when EBTRBn = 0.
TABLAT register returns the value of the data at the location TBLPTR.
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DS40001365F-page 263
PIC18(L)F1XK22
23.3.2
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.
23.3.3
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
readable only. WRTC can only be written via ICSP or
an external programmer.
23.4
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.
23.5
In-Circuit Serial Programming
PIC18(L)F1XK22 devices 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.
23.6
In-Circuit Debugger
When the DEBUG Configuration bit is programmed to
a ‘0’, the In-Circuit Debugger functionality is enabled.
This function allows simple debugging functions when
used with MPLAB® IDE. When the microcontroller has
this feature enabled, some resources are not available
for general use. Table 23-4 shows which resources are
required by the background debugger.
TABLE 23-4:
DEBUGGER RESOURCES
I/O pins:
RA0, RA1
Stack:
2 levels
Program Memory:
512 bytes
Data Memory:
10 bytes
DS40001365F-page 264
To use the In-Circuit Debugger function of the
microcontroller, the design must implement In-Circuit
Serial Programming connections to the following pins:
•
•
•
•
•
MCLR/VPP/RA3
VDD
VSS
RA0
RA1
This will interface to the In-Circuit Debugger module
available from Microchip or one of the third party
development tool companies.
23.7
Single-Supply ICSP Programming
The LVP Configuration bit enables Single-Supply ICSP
Programming (formerly known as Low-Voltage ICSP
Programming or LVP). When Single-Supply
Programming is enabled, the microcontroller can be
programmed without requiring high voltage being
applied to the MCLR/VPP/RA3 pin, but the RC3/PGM
pin is then dedicated to controlling Program mode entry
and is not available as a general purpose I/O pin.
While programming, using Single-Supply Programming
mode, VDD is applied to the MCLR/VPP/RA3 pin as in
normal execution mode. To enter Programming mode,
VDD is applied to the PGM pin.
Note 1: High-voltage programming is always
available, regardless of the state of the
LVP bit or the PGM pin, by applying VIHH
to the MCLR pin.
2: By default, Single-Supply ICSP is
enabled in unprogrammed devices (as
supplied from Microchip) and erased
devices.
3: When Single-Supply Programming is
enabled, the RC3 pin can no longer be
used as a general purpose I/O pin.
4: When LVP is enabled, externally pull the
PGM pin to VSS to allow normal program
execution.
If Single-Supply ICSP Programming mode will not be
used, the LVP bit can be cleared. RC3/PGM then
becomes available as the digital I/O pin, RC3. The LVP
bit may be set or cleared only when using standard
high-voltage programming (VIHH applied to the MCLR/
VPP/RA3 pin). Once LVP has been disabled, only the
standard high-voltage programming is available and
must be used to program the device.
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.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
24.0
INSTRUCTION SET SUMMARY
PIC18(L)F1XK22 devices incorporate the standard set
of 75 PIC18 core instructions, as well as an extended set
of eight 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.
24.1
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 24-2 lists
byte-oriented, bit-oriented, literal and control
operations. Table 24-1 shows the opcode field
descriptions.
Most byte-oriented instructions have three operands:
1.
2.
3.
The file register (specified by ‘f’)
The destination of the result (specified by ‘d’)
The accessed memory (specified by ‘a’)
The file register designator ‘f’ specifies which file
register is to be used by the instruction. The destination
designator ‘d’ specifies where the result of the
operation is to be placed. If ‘d’ is 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.
2.
3.
The file register (specified by ‘f’)
The bit in the file register (specified by ‘b’)
The accessed memory (specified by ‘a’)
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 1s. If a conditional test is
true, or the program counter is changed as a result of
an instruction, the instruction execution time is 2s.
Two-word branch instructions (if true) would take 3s.
Figure 24-1 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 24-2,
lists the standard instructions recognized by the
Microchip Assembler (MPASMTM).
Section 24.1.1 “Standard Instruction Set” provides
a description of each instruction.
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.
2009-2016 Microchip Technology Inc.
DS40001365F-page 265
PIC18(L)F1XK22
TABLE 24-1:
OPCODE FIELD DESCRIPTIONS
Field
Description
a
RAM 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.
d
Destination 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.
f
8-bit Register file address (00h to FFh) or 2-bit FSR designator (0h to 3h).
fs
12-bit Register file address (000h to FFFh). This is the source address.
fd
12-bit Register file address (000h to FFFh). This is the destination address.
GIE
Global Interrupt Enable bit.
k
Literal 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)
+*
n
The 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.
s
Fast 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.
u
Unused or unchanged.
WDT
Watchdog Timer.
WREG
Working register (accumulator).
x
Don’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.
zs
7-bit offset value for indirect addressing of register files (source).
7-bit offset value for indirect addressing of register files (destination).
zd
{
}
Optional argument.
[text]
Indicates an indexed address.
(text)
The contents of text.
[expr]
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).
DS40001365F-page 266
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 24-1:
GENERAL FORMAT FOR INSTRUCTIONS
Byte-oriented file register operations
15
10
9 8 7
OPCODE d
a
Example Instruction
0
f (FILE #)
ADDWF MYREG, W, B
d = 0 for result destination to be WREG register
d = 1 for result destination to be file register (f)
a = 0 to force Access Bank
a = 1 for BSR to select bank
f = 8-bit file register address
Byte to Byte move operations (2-word)
15
12 11
OPCODE
15
0
f (Source FILE #)
12 11
MOVFF MYREG1, MYREG2
0
f (Destination FILE #)
1111
f = 12-bit file register address
Bit-oriented file register operations
15
12 11
9 8 7
OPCODE b (BIT #) a
0
f (FILE #)
BSF MYREG, bit, B
b = 3-bit position of bit in file register (f)
a = 0 to force Access Bank
a = 1 for BSR to select bank
f = 8-bit file register address
Literal operations
15
8
7
OPCODE
0
k (literal)
MOVLW 7Fh
k = 8-bit immediate value
Control operations
CALL, GOTO and Branch operations
15
8 7
OPCODE
15
0
n (literal)
12 11
GOTO Label
0
n (literal)
1111
n = 20-bit immediate value
15
8 7
OPCODE
15
S
0
n (literal)
12 11
CALL MYFUNC
0
n (literal)
1111
S = Fast bit
15
11 10
OPCODE
15
OPCODE
2009-2016 Microchip Technology Inc.
0
n (literal)
8 7
n (literal)
BRA MYFUNC
0
BC MYFUNC
DS40001365F-page 267
PIC18(L)F1XK22
TABLE 24-2:
PIC18FXXXX INSTRUCTION SET
16-Bit Instruction Word
Mnemonic,
Operands
Description
Cycles
MSb
LSb
Status
Affected
Notes
BYTE-ORIENTED OPERATIONS
ADDWF
ADDWFC
ANDWF
CLRF
COMF
CPFSEQ
CPFSGT
CPFSLT
DECF
DECFSZ
DCFSNZ
INCF
INCFSZ
INFSNZ
IORWF
MOVF
MOVFF
f, d, a
f, d, a
f, d, a
f, a
f, d, a
f, a
f, a
f, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
fs, fd
MOVWF
MULWF
NEGF
RLCF
RLNCF
RRCF
RRNCF
SETF
SUBFWB
f, a
f, a
f, a
f, d, a
f, d, a
f, d, a
f, d, a
f, a
f, d, a
SUBWF
SUBWFB
f, d, a
f, d, a
SWAPF
TSTFSZ
XORWF
f, d, a
f, a
f, d, a
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’.
If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if
assigned.
If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is
executed as a NOP.
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.
2:
3:
4:
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
DS40001365F-page 268
1
1
1
1
1
1 (2 or 3)
1 (2 or 3)
1 (2 or 3)
1
1 (2 or 3)
1 (2 or 3)
1
1 (2 or 3)
1 (2 or 3)
1
1
2
C, DC, Z, OV, N
C, DC, Z, OV, N
Z, N
Z
Z, N
None
None
None
C, DC, Z, OV, N
None
None
C, DC, Z, OV, N
None
None
Z, N
Z, N
None
1, 2
1, 2
1, 2
2
1, 2
4
4
1, 2
1, 2, 3, 4
1, 2, 3, 4
1, 2
1, 2, 3, 4
4
1, 2
1, 2
1
1
1
1
1
1
1
1
1
1
0010
0010
0001
0110
0001
0110
0110
0110
0000
0010
0100
0010
0011
0100
0001
0101
1100
1111
0110
0000
0110
0011
0100
0011
0100
0110
0101
01da
00da
01da
101a
11da
001a
010a
000a
01da
11da
11da
10da
11da
10da
00da
00da
ffff
ffff
111a
001a
110a
01da
01da
00da
00da
100a
01da
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
1
1
0101
0101
11da
10da
ffff
ffff
ffff C, DC, Z, OV, N
ffff C, DC, Z, OV, N
1, 2
1
1 (2 or 3)
1
0011
0110
0001
10da
011a
10da
ffff
ffff
ffff
ffff None
ffff None
ffff Z, N
4
1, 2
None
None
C, DC, Z, OV, N
C, Z, N
Z, N
C, Z, N
Z, N
None
C, DC, Z, OV, N
1, 2
1, 2
1, 2
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 24-2:
PIC18FXXXX INSTRUCTION SET (CONTINUED)
16-Bit Instruction Word
Mnemonic,
Operands
Description
Cycles
MSb
LSb
Status
Affected
Notes
BIT-ORIENTED OPERATIONS
BCF
BSF
BTFSC
BTFSS
BTG
f, b, a
f, b, a
f, b, a
f, b, a
f, b, a
Bit Clear f
Bit Set f
Bit Test f, Skip if Clear
Bit Test f, Skip if Set
Bit Toggle f
1
1
1 (2 or 3)
1 (2 or 3)
1
1001
1000
1011
1010
0111
bbba
bbba
bbba
bbba
bbba
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
None
None
None
None
None
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
2
1 (2)
2
0010
0110
0011
0111
0101
0001
0100
0nnn
0000
110s
kkkk
0000
0000
1111
kkkk
0000
xxxx
0000
0000
1nnn
0000
0000
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
kkkk
kkkk
0000
0000
kkkk
kkkk
0000
xxxx
0000
0000
nnnn
1111
0001
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
kkkk
kkkk
0100
0111
kkkk
kkkk
0000
xxxx
0110
0101
nnnn
1111
000s
None
None
None
None
None
None
None
None
None
None
1
1
1
1
2
1
2
1110
1110
1110
1110
1110
1110
1110
1101
1110
1110
1111
0000
0000
1110
1111
0000
1111
0000
0000
1101
0000
0000
2
2
1
0000
0000
0000
1100
0000
0000
kkkk
0001
0000
1, 2
1, 2
3, 4
3, 4
1, 2
CONTROL OPERATIONS
BC
BN
BNC
BNN
BNOV
BNZ
BOV
BRA
BZ
CALL
n
n
n
n
n
n
n
n
n
k, s
CLRWDT
DAW
GOTO
—
—
k
NOP
NOP
POP
PUSH
RCALL
RESET
RETFIE
—
—
—
—
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
No Operation
Pop top of return stack (TOS)
Push top of return stack (TOS)
Relative Call
Software device Reset
Return from interrupt enable
RETLW
RETURN
SLEEP
k
s
—
Return with literal in WREG
Return from Subroutine
Go into Standby mode
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’.
If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if
assigned.
If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is
executed as a NOP.
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.
2:
3:
4:
2009-2016 Microchip Technology Inc.
1
1
2
TO, PD
C
None
None
None
None
None
None
All
GIE/GIEH,
PEIE/GIEL
kkkk None
001s None
0011 TO, PD
4
DS40001365F-page 269
PIC18(L)F1XK22
TABLE 24-2:
PIC18FXXXX INSTRUCTION SET (CONTINUED)
16-Bit Instruction Word
Mnemonic,
Operands
Description
Cycles
MSb
LSb
Status
Affected
Notes
LITERAL OPERATIONS
ADDLW
ANDLW
IORLW
LFSR
k
k
k
f, k
MOVLB
MOVLW
MULLW
RETLW
SUBLW
XORLW
k
k
k
k
k
k
Add literal and WREG
AND literal with WREG
Inclusive OR literal with WREG
Move literal (12-bit) 2nd word
to FSR(f)
1st word
Move literal to BSR
Move literal to WREG
Multiply literal with WREG
Return with literal in WREG
Subtract WREG from literal
Exclusive OR literal with WREG
1
1
1
2
1
1
1
2
1
1
0000
0000
0000
1110
1111
0000
0000
0000
0000
0000
0000
1111
1011
1001
1110
0000
0001
1110
1101
1100
1000
1010
kkkk
kkkk
kkkk
00ff
kkkk
0000
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
C, DC, Z, OV, N
Z, N
Z, N
None
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
1000
1001
1010
1011
1100
1101
1110
1111
None
None
None
None
None
None
None
None
None
None
None
None
C, DC, Z, OV, N
Z, N
DATA MEMORY PROGRAM MEMORY OPERATIONS
TBLRD*
TBLRD*+
TBLRD*TBLRD+*
TBLWT*
TBLWT*+
TBLWT*TBLWT+*
Note 1:
2:
3:
4:
Table Read
Table Read with post-increment
Table Read with post-decrement
Table Read with pre-increment
Table Write
Table Write with post-increment
Table Write with post-decrement
Table Write with pre-increment
2
2
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’.
If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared if
assigned.
If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is
executed as a NOP.
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.
DS40001365F-page 270
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
24.1.1
STANDARD INSTRUCTION SET
ADDLW
ADD literal to W
ADDWF
ADD W to f
Syntax:
ADDLW
Syntax:
ADDWF
Operands:
0 f 255
d [0,1]
a [0,1]
Operation:
(W) + (f) dest
Status Affected:
N, OV, C, DC, Z
k
Operands:
0 k 255
Operation:
(W) + k W
Status Affected:
N, OV, C, DC, Z
Encoding:
0000
1111
kkkk
kkkk
Description:
The contents of W are added to the
8-bit literal ‘k’ and the result is placed in
W.
Words:
1
Cycles:
1
Encoding:
0010
Q1
Q2
Q3
Q4
Read
literal ‘k’
Process
Data
Write to W
Example:
ADDLW
=
25h
ffff
Words:
1
Cycles:
1
Before Instruction
W
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
15h
W
= 10h
After Instruction
01da
Description:
Q Cycle Activity:
Decode
f {,d {,a}}
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
ADDWF
REG, 0, 0
Before Instruction
W
=
REG
=
After Instruction
W
REG
Note:
=
=
17h
0C2h
0D9h
0C2h
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).
2009-2016 Microchip Technology Inc.
DS40001365F-page 271
PIC18(L)F1XK22
ADDWFC
ADD W and CARRY bit to f
ANDLW
Syntax:
ADDWFC
Syntax:
ANDLW
Operands:
0 f 255
d [0,1]
a [0,1]
Operands:
0 k 255
Operation:
(W) .AND. k W
Status Affected:
N, Z
f {,d {,a}}
Operation:
(W) + (f) + (C) dest
Status Affected:
N,OV, C, DC, Z
Encoding:
0010
Description:
00da
Encoding:
ffff
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
AND literal with W
0000
k
1011
kkkk
kkkk
Description:
The contents of W are AND’ed 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
=
After Instruction
W
=
A3h
03h
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
ADDWFC
Before Instruction
CARRY bit =
REG
=
W
=
After Instruction
CARRY bit =
REG
=
W
=
DS40001365F-page 272
REG, 0, 1
1
02h
4Dh
0
02h
50h
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
ANDWF
AND W with f
BC
Branch if Carry
Syntax:
ANDWF
Syntax:
BC
Operands:
0 f 255
d [0,1]
a [0,1]
Operands:
-128 n 127
Operation:
if CARRY bit is ‘1’
(PC) + 2 + 2n PC
Status Affected:
None
f {,d {,a}}
Operation:
(W) .AND. (f) dest
Status Affected:
N, Z
Encoding:
0001
Description:
Encoding:
01da
ffff
ffff
The contents of W are AND’ed with
register ‘f’. If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is ‘1’, the result is stored back
in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
ANDWF
REG, 0, 0
Before Instruction
W
=
REG
=
After Instruction
W
REG
=
=
17h
C2h
02h
C2h
2009-2016 Microchip Technology Inc.
n
1110
Description:
0010
nnnn
nnnn
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
2-cycle instruction.
Words:
1
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
HERE
Before Instruction
PC
After Instruction
If CARRY
PC
If CARRY
PC
BC
5
=
address (HERE)
=
=
=
=
1;
address (HERE + 12)
0;
address (HERE + 2)
DS40001365F-page 273
PIC18(L)F1XK22
BCF
Bit Clear f
BN
Branch if Negative
Syntax:
BCF
Syntax:
BN
Operands:
0 f 255
0b7
a [0,1]
Operands:
-128 n 127
Operation:
if NEGATIVE bit is ‘1’
(PC) + 2 + 2n PC
Status Affected:
None
f, b {,a}
Operation:
0 f
Status Affected:
None
Encoding:
Encoding:
1001
Description:
bbba
ffff
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
BCF
Before Instruction
FLAG_REG =
After Instruction
FLAG_REG =
DS40001365F-page 274
FLAG_REG,
7, 0
n
1110
Description:
0110
nnnn
nnnn
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
2-cycle instruction.
Words:
1
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
C7h
47h
Example:
HERE
Before Instruction
PC
After Instruction
If NEGATIVE
PC
If NEGATIVE
PC
BN
Jump
=
address (HERE)
=
=
=
=
1;
address (Jump)
0;
address (HERE + 2)
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
BNC
Branch if Not Carry
BNN
Branch if Not Negative
Syntax:
BNC
Syntax:
BNN
Operands:
-128 n 127
Operands:
-128 n 127
Operation:
if CARRY bit is ‘0’
(PC) + 2 + 2n PC
Operation:
if NEGATIVE bit is ‘0’
(PC) + 2 + 2n PC
Status Affected:
None
Status Affected:
None
Encoding:
n
1110
Description:
0011
nnnn
nnnn
Encoding:
1110
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
2-cycle instruction.
Description:
Words:
1
Words:
1
Cycles:
1(2)
Cycles:
1(2)
Q Cycle Activity:
If Jump:
n
0111
nnnn
nnnn
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
2-cycle instruction.
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to PC
Decode
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Decode
Read literal
‘n’
Process
Data
No
operation
If No Jump:
Example:
If No Jump:
HERE
Before Instruction
PC
After Instruction
If CARRY
PC
If CARRY
PC
BNC
Jump
=
address (HERE)
=
=
=
=
0;
address (Jump)
1;
address (HERE + 2)
2009-2016 Microchip Technology Inc.
Example:
HERE
Before Instruction
PC
After Instruction
If NEGATIVE
PC
If NEGATIVE
PC
BNN
Jump
=
address (HERE)
=
=
=
=
0;
address (Jump)
1;
address (HERE + 2)
DS40001365F-page 275
PIC18(L)F1XK22
BNOV
Branch if Not Overflow
BNZ
Branch if Not Zero
Syntax:
BNOV
Syntax:
BNZ
Operands:
-128 n 127
Operands:
-128 n 127
Operation:
if OVERFLOW bit is ‘0’
(PC) + 2 + 2n PC
Operation:
if ZERO bit is ‘0’
(PC) + 2 + 2n PC
Status Affected:
None
Status Affected:
None
Encoding:
n
1110
Description:
0101
nnnn
nnnn
Encoding:
1110
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
2-cycle instruction.
Description:
Words:
1
Words:
1
Cycles:
1(2)
Cycles:
1(2)
Q Cycle Activity:
If Jump:
n
0001
nnnn
nnnn
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
2-cycle instruction.
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to PC
Decode
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Decode
Read literal
‘n’
Process
Data
No
operation
If No Jump:
Example:
If No Jump:
HERE
Before Instruction
PC
=
After Instruction
If OVERFLOW =
PC
=
If OVERFLOW =
PC
=
DS40001365F-page 276
BNOV Jump
address (HERE)
0;
address (Jump)
1;
address (HERE + 2)
Example:
HERE
Before Instruction
PC
After Instruction
If ZERO
PC
If ZERO
PC
BNZ
Jump
=
address (HERE)
=
=
=
=
0;
address (Jump)
1;
address (HERE + 2)
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
BRA
Unconditional Branch
BSF
Syntax:
BRA
Syntax:
BSF
Operands:
-1024 n 1023
Operands:
0 f 255
0b7
a [0,1]
n
Operation:
(PC) + 2 + 2n PC
Status Affected:
None
Encoding:
1101
Description:
0nnn
nnnn
nnnn
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 2-cycle instruction.
Words:
1
Cycles:
2
Bit Set f
Operation:
1 f
Status Affected:
None
Encoding:
1000
Q1
Q2
Q3
Q4
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
Example:
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Decode
f, b {,a}
Q Cycle Activity:
HERE
Before Instruction
PC
After Instruction
PC
BRA
Jump
=
address (HERE)
=
address (Jump)
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
BSF
Before Instruction
FLAG_REG
After Instruction
FLAG_REG
2009-2016 Microchip Technology Inc.
FLAG_REG, 7, 1
=
0Ah
=
8Ah
DS40001365F-page 277
PIC18(L)F1XK22
BTFSC
Bit Test File, Skip if Clear
BTFSS
Syntax:
BTFSC f, b {,a}
Syntax:
BTFSS f, b {,a}
Operands:
0 f 255
0b7
a [0,1]
Operands:
0 f 255
0b (W)
(unsigned comparison)
Operation:
(f) –W),
skip if (f) < (W)
(unsigned comparison)
Status Affected:
None
Status Affected:
None
Encoding:
0110
Description:
Words:
f {,a}
010a
ffff
ffff
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
2-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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Encoding:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q2
Read
register ‘f’
Q3
Process
Data
Q4
No
operation
Q1
Q2
Q3
No
No
No
operation
operation
operation
If skip and followed by 2-word instruction:
Q1
Q2
Q3
No
No
No
operation
operation
operation
No
No
No
operation
operation
operation
Q4
No
operation
Example:
HERE
NGREATER
GREATER
CPFSGT REG, 0
:
:
Before Instruction
PC
W
After Instruction
=
=
Address (HERE)
?
If REG
PC
If REG
PC
=
=
W;
Address (GREATER)
W;
Address (NGREATER)
2009-2016 Microchip Technology Inc.
ffff
ffff
Words:
1
Cycles:
1(2)
Note: Three cycles if skip and
followed by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
No
operation
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
If skip:
If skip and followed by 2-word instruction:
If skip:
Q4
No
operation
No
operation
000a
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
2-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).
Q Cycle Activity:
Q1
Decode
0110
Description:
1
Cycles:
f {,a}
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example:
HERE
NLESS
LESS
CPFSLT REG, 1
:
:
Before Instruction
PC
W
After Instruction
=
=
Address (HERE)
?
If REG
PC
If REG
PC
<
=
=
W;
Address (LESS)
W;
Address (NLESS)
DS40001365F-page 283
PIC18(L)F1XK22
DAW
Decimal Adjust W Register
DECF
Syntax:
DAW
Syntax:
DECF f {,d {,a}}
Operands:
None
Operands:
Operation:
If [W > 9] or [DC = 1] then
(W) + 6 W;
else
(W) W;
0 f 255
d [0,1]
a [0,1]
Operation:
(f) – 1 dest
Status Affected:
C, DC, N, OV, Z
If [W + DC > 9] or [C = 1] then
(W) + 6 + DC W;
else
(W) + DC W
Status Affected:
Decrement f
Encoding:
0000
0000
0000
0000
0111
Description:
DAW adjusts the 8-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
Words:
1
Decode
Read
register W
Process
Data
Write
W
Cycles:
1
Example1:
DAW
Before Instruction
W
=
C
=
DC
=
After Instruction
W
C
DC
Example 2:
=
=
=
A5h
0
0
05h
1
0
Before Instruction
W
=
C
=
DC
=
After Instruction
W
C
DC
=
=
=
DS40001365F-page 284
ffff
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
C
Encoding:
01da
Description:
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
DECF
Before Instruction
CNT
=
Z
=
After Instruction
CNT
=
Z
=
CNT,
1, 0
01h
0
00h
1
CEh
0
0
34h
1
0
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
DECFSZ
Decrement f, skip if 0
DCFSNZ
Syntax:
DECFSZ f {,d {,a}}
Syntax:
DCFSNZ
Operands:
0 f 255
d [0,1]
a [0,1]
Operands:
0 f 255
d [0,1]
a [0,1]
Operation:
(f) – 1 dest,
skip if result = 0
Operation:
(f) – 1 dest,
skip if result 0
Status Affected:
None
Status Affected:
None
Encoding:
0010
Description:
11da
ffff
ffff
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 2-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 24.2.3 “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.
Decrement f, skip if not 0
Encoding:
0100
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
HERE
DECFSZ
GOTO
Example:
CNT, 1, 1
LOOP
CONTINUE
Before Instruction
PC
=
After Instruction
CNT
=
If CNT
=
PC =
If CNT
PC =
Address (HERE)
CNT - 1
0;
Address (CONTINUE)
0;
Address (HERE + 2)
2009-2016 Microchip Technology Inc.
ffff
ffff
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 2-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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1(2)
Note:
3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
If skip:
If skip and followed by 2-word instruction:
11da
Description:
Q Cycle Activity:
Q1
f {,d {,a}}
If skip:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example:
HERE
ZERO
NZERO
Before Instruction
TEMP
After Instruction
TEMP
If TEMP
PC
If TEMP
PC
DCFSNZ
:
:
TEMP, 1, 0
=
?
=
=
=
=
TEMP – 1,
0;
Address (ZERO)
0;
Address (NZERO)
DS40001365F-page 285
PIC18(L)F1XK22
GOTO
Unconditional Branch
INCF
Syntax:
GOTO k
Syntax:
INCF
Operands:
0 k 1048575
Operands:
Operation:
k PC
Status Affected:
None
0 f 255
d [0,1]
a [0,1]
Operation:
(f) + 1 dest
Status Affected:
C, DC, N, OV, Z
Encoding:
1st word (k)
2nd word(k)
Description:
1110
1111
1111
k19kkk
k7kkk
kkkk
kkkk0
kkkk8
GOTO allows an unconditional branch
Increment f
Encoding:
0010
2
Cycles:
2
Q1
Q2
Q3
Q4
Read literal
‘k’,
No
operation
Read literal
‘k’,
Write to PC
No
operation
No
operation
No
operation
No
operation
Example:
GOTO THERE
After Instruction
PC =
Address (THERE)
ffff
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
INCF
Before Instruction
CNT
=
Z
=
C
=
DC
=
After Instruction
CNT
=
Z
=
C
=
DC
=
DS40001365F-page 286
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Q Cycle Activity:
Decode
10da
Description:
anywhere within entire 2-Mbyte memory
range. The 20-bit value ‘k’ is loaded into
PC. GOTO is always a 2-cycle
instruction.
Words:
f {,d {,a}}
CNT, 1, 0
FFh
0
?
?
00h
1
1
1
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
INCFSZ
Increment f, skip if 0
INFSNZ
Syntax:
INCFSZ
Syntax:
INFSNZ
0 f 255
d [0,1]
a [0,1]
f {,d {,a}}
Increment f, skip if not 0
f {,d {,a}}
Operands:
0 f 255
d [0,1]
a [0,1]
Operands:
Operation:
(f) + 1 dest,
skip if result = 0
Operation:
(f) + 1 dest,
skip if result 0
Status Affected:
None
Status Affected:
None
Encoding:
0011
Description:
11da
ffff
ffff
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 2-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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Encoding:
0100
Description:
Words:
1
Words:
1
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Cycles:
1(2)
Note:
Q Cycle Activity:
10da
ffff
ffff
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 2-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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Decode
Read
register ‘f’
Process
Data
Write to
destination
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
If skip:
If skip:
If skip and followed by 2-word instruction:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example:
HERE
NZERO
ZERO
Before Instruction
PC
=
After Instruction
CNT
=
If CNT
=
PC
=
If CNT
PC
=
INCFSZ
:
:
Address (HERE)
CNT + 1
0;
Address (ZERO)
0;
Address (NZERO)
2009-2016 Microchip Technology Inc.
CNT, 1, 0
Example:
HERE
ZERO
NZERO
Before Instruction
PC
=
After Instruction
REG
=
If REG
PC
=
If REG
=
PC
=
INFSNZ
REG, 1, 0
Address (HERE)
REG + 1
0;
Address (NZERO)
0;
Address (ZERO)
DS40001365F-page 287
PIC18(L)F1XK22
IORLW
Inclusive OR literal with W
IORWF
Syntax:
IORLW k
Syntax:
IORWF
Operands:
0 k 255
Operands:
Operation:
(W) .OR. k W
Status Affected:
N, Z
0 f 255
d [0,1]
a [0,1]
Operation:
(W) .OR. (f) dest
Status Affected:
N, Z
Encoding:
0000
Description:
1001
kkkk
kkkk
The contents of W are ORed with the 8bit literal ‘k’. The result is placed in W.
Words:
1
Cycles:
1
Inclusive OR W with f
Encoding:
0001
Q1
Q2
Q3
Q4
Read
literal ‘k’
Process
Data
Write to W
Example:
IORLW
W
=
ffff
Words:
1
Cycles:
1
35h
9Ah
BFh
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Before Instruction
W
=
After Instruction
00da
Description:
Q Cycle Activity:
Decode
f {,d {,a}}
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
IORWF
Before Instruction
RESULT =
W
=
After Instruction
RESULT =
W
=
DS40001365F-page 288
RESULT, 0, 1
13h
91h
13h
93h
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
LFSR
Load FSR
MOVF
Syntax:
LFSR f, k
Syntax:
MOVF
Operands:
0f2
0 k 4095
Operands:
Operation:
k FSRf
0 f 255
d [0,1]
a [0,1]
Status Affected:
None
Operation:
f dest
Status Affected:
N, Z
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
Move f
Encoding:
0101
Q1
Q2
Q3
Q4
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:
After Instruction
FSR2H
FSR2L
03h
ABh
ffff
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
LFSR 2, 3ABh
=
=
00da
Description:
Q Cycle Activity:
Decode
f {,d {,a}}
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write W
Example:
MOVF
Before Instruction
REG
W
After Instruction
REG
W
2009-2016 Microchip Technology Inc.
REG, 0, 0
=
=
22h
FFh
=
=
22h
22h
DS40001365F-page 289
PIC18(L)F1XK22
MOVFF
Move f to f
MOVLB
Syntax:
MOVFF fs,fd
Syntax:
MOVLB k
Operands:
0 fs 4095
0 fd 4095
Operands:
0 k 255
Operation:
k BSR
Operation:
(fs) fd
Status Affected:
None
Status Affected:
None
Encoding:
Encoding:
1st word (source)
2nd word (destin.)
Description:
1100
1111
ffff
ffff
ffff
ffff
ffffs
ffffd
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)
Move literal to low nibble in BSR
0000
0001
0000
kkkk
Description:
The 8-bit literal ‘k’ is loaded into the
Bank Select Register (BSR). The value
of BSR 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
MOVLB
5
Example:
Before Instruction
BSR Register =
After Instruction
BSR Register =
02h
05h
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
(src)
Process
Data
No
operation
Decode
No
operation
No
operation
Write
register ‘f’
(dest)
No dummy
read
Example:
MOVFF
Before Instruction
REG1
REG2
After Instruction
REG1
REG2
DS40001365F-page 290
REG1, REG2
=
=
33h
11h
=
=
33h
33h
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
MOVLW
Move literal to W
MOVWF
Syntax:
MOVLW k
Syntax:
MOVWF
Operands:
0 k 255
Operands:
Operation:
kW
0 f 255
a [0,1]
Status Affected:
None
Operation:
(W) f
Status Affected:
None
Encoding:
0000
1110
kkkk
kkkk
Description:
The 8-bit literal ‘k’ is loaded into W.
Words:
1
Cycles:
1
Move W to f
Encoding:
0110
Q1
Q2
Q3
Q4
Read
literal ‘k’
Process
Data
Write to W
Example:
MOVLW
=
ffff
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
5Ah
After Instruction
W
111a
Description:
Q Cycle Activity:
Decode
f {,a}
5Ah
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
MOVWF
REG, 0
Before Instruction
W
=
REG
=
After Instruction
W
REG
2009-2016 Microchip Technology Inc.
=
=
4Fh
FFh
4Fh
4Fh
DS40001365F-page 291
PIC18(L)F1XK22
MULLW
Multiply literal with W
MULWF
Multiply W with f
Syntax:
MULLW
Syntax:
MULWF
Operands:
0 k 255
Operands:
Operation:
(W) x k PRODH:PRODL
0 f 255
a [0,1]
Status Affected:
None
Operation:
(W) x (f) PRODH:PRODL
Status Affected:
None
Encoding:
0000
Description:
k
1101
kkkk
kkkk
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
Encoding:
0000
Q1
Q2
Q3
Q4
Read
literal ‘k’
Process
Data
Write
registers
PRODH:
PRODL
Example:
MULLW
W
PRODH
PRODL
After Instruction
W
PRODH
PRODL
=
=
=
E2h
?
?
=
=
=
E2h
ADh
08h
ffff
ffff
An unsigned multiplication is carried
out between the contents of W and the
register file location ‘f’. The 16-bit
result is stored in the PRODH:PRODL
register pair. PRODH contains the
high byte. Both W and ‘f’ are
unchanged.
None of the Status flags are affected.
Note that neither overflow nor carry is
possible in this operation. A zero
result is possible but not detected.
If ‘a’ 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 24.2.3
“Byte-Oriented and Bit-Oriented
Instructions in Indexed Literal Offset
Mode” for details.
Words:
1
Cycles:
1
0C4h
Before Instruction
001a
Description:
Q Cycle Activity:
Decode
f {,a}
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
registers
PRODH:
PRODL
Example:
MULWF
REG, 1
Before Instruction
W
REG
PRODH
PRODL
After Instruction
W
REG
PRODH
PRODL
DS40001365F-page 292
=
=
=
=
C4h
B5h
?
?
=
=
=
=
C4h
B5h
8Ah
94h
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
NEGF
Negate f
NOP
No Operation
Syntax:
NEGF
Syntax:
NOP
Operands:
0 f 255
a [0,1]
Operands:
None
Operation:
(f)+1f
Status Affected:
N, OV, C, DC, Z
Encoding:
f {,a}
0110
Description:
1
Cycles:
1
No operation
Status Affected:
None
Encoding:
110a
ffff
0000
1111
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Operation:
0000
xxxx
Description:
No operation.
Words:
1
Cycles:
1
0000
xxxx
0000
xxxx
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
No
operation
No
operation
Example:
None.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
NEGF
Before Instruction
REG
=
After Instruction
REG
=
REG, 1
0011 1010 [3Ah]
1100 0110 [C6h]
2009-2016 Microchip Technology Inc.
DS40001365F-page 293
PIC18(L)F1XK22
POP
Pop Top of Return Stack
PUSH
Push Top of Return Stack
Syntax:
POP
Syntax:
PUSH
Operands:
None
Operands:
None
Operation:
(TOS) bit bucket
Operation:
(PC + 2) TOS
Status Affected:
None
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
Encoding:
0000
0000
0101
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:
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
POP TOS
value
No
operation
POP
GOTO
NEW
Example:
0000
Description:
Before Instruction
TOS
Stack (1 level down)
After Instruction
TOS
PC
DS40001365F-page 294
Q1
Q2
Q3
Q4
Decode
PUSH
PC + 2 onto
return stack
No
operation
No
operation
Example:
=
=
0031A2h
014332h
=
=
014332h
NEW
PUSH
Before Instruction
TOS
PC
=
=
345Ah
0124h
After Instruction
PC
TOS
Stack (1 level down)
=
=
=
0126h
0126h
345Ah
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
RCALL
Relative Call
RESET
Reset
Syntax:
RCALL
Syntax:
RESET
Operands:
-1024 n 1023
Operands:
None
Operation:
(PC) + 2 TOS,
(PC) + 2 + 2n PC
Operation:
Reset all registers and flags that are
affected by a MCLR Reset.
Status Affected:
None
Status Affected:
All
Encoding:
n
1101
Description:
1nnn
nnnn
nnnn
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
2-cycle instruction.
Words:
1
Cycles:
2
Encoding:
0000
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
1111
1111
Description:
This instruction provides a way to
execute a MCLR Reset by software.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Start
Reset
No
operation
No
operation
Example:
Q Cycle Activity:
0000
After Instruction
Registers =
Flags*
=
RESET
Reset Value
Reset Value
PUSH PC to
stack
No
operation
Example:
No
operation
HERE
RCALL Jump
Before Instruction
PC =
Address (HERE)
After Instruction
PC =
Address (Jump)
TOS =
Address (HERE + 2)
2009-2016 Microchip Technology Inc.
DS40001365F-page 295
PIC18(L)F1XK22
RETFIE
Return from Interrupt
RETLW
Return literal to W
Syntax:
RETFIE {s}
Syntax:
RETLW k
Operands:
s [0,1]
Operands:
0 k 255
Operation:
(TOS) PC,
1 GIE/GIEH or PEIE/GIEL,
if s = 1
(WS) W,
(STATUSS) Status,
(BSRS) BSR,
PCLATU, PCLATH are unchanged.
Operation:
k W,
(TOS) PC,
PCLATU, PCLATH are unchanged
Status Affected:
None
Status Affected:
0000
0000
0001
1
Cycles:
2
Q Cycle Activity:
kkkk
kkkk
Words:
1
Cycles:
2
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
POP PC
from stack,
Write to W
No
operation
No
operation
No
operation
No
operation
Example:
Q1
Q2
Q3
Q4
Decode
No
operation
No
operation
POP PC
from stack
Set GIEH or
GIEL
Example:
1100
W is loaded with the 8-bit literal ‘k’. The
program counter is loaded from the top
of the stack (the return address). The
high address latch (PCLATH) remains
unchanged.
000s
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:
No
operation
0000
Description:
GIE/GIEH, PEIE/GIEL
Encoding:
Description:
Encoding:
No
operation
RETFIE
After Interrupt
PC
W
BSR
Status
GIE/GIEH, PEIE/GIEL
DS40001365F-page 296
No
operation
No
operation
1
=
=
=
=
=
TOS
WS
BSRS
STATUSS
1
CALL TABLE ;
;
;
;
:
TABLE
ADDWF PCL ;
RETLW k0
;
RETLW k1
;
:
:
RETLW kn
;
Before Instruction
W
=
After Instruction
W
=
W contains table
offset value
W now has
table value
W = offset
Begin table
End of table
07h
value of kn
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
RETURN
Return from Subroutine
RLCF
Syntax:
RETURN {s}
Syntax:
RLCF
Operands:
s [0,1]
Operands:
Operation:
(TOS) PC,
if s = 1
(WS) W,
(STATUSS) Status,
(BSRS) BSR,
PCLATU, PCLATH are unchanged
0 f 255
d [0,1]
a [0,1]
Operation:
(f) dest,
(f) C,
(C) dest
Status Affected:
C, N, Z
Status Affected:
None
Encoding:
0000
Rotate Left f through Carry
Encoding:
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
0011
Description:
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
Process
Data
POP PC
from stack
No
operation
No
operation
No
operation
No
operation
f {,d {,a}}
01da
ffff
ffff
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 24.2.3
“Byte-Oriented and Bit-Oriented
Instructions in Indexed Literal Offset
Mode” for details.
register f
C
Words:
1
Cycles:
1
Q Cycle Activity:
Example:
RETURN
After Instruction:
PC = TOS
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
Before Instruction
REG
=
C
=
After Instruction
REG
=
W
=
C
=
2009-2016 Microchip Technology Inc.
RLCF
REG, 0, 0
1110 0110
0
1110 0110
1100 1100
1
DS40001365F-page 297
PIC18(L)F1XK22
RLNCF
Rotate Left f (No Carry)
RRCF
Syntax:
RLNCF
Syntax:
RRCF
Operands:
0 f 255
d [0,1]
a [0,1]
Operands:
0 f 255
d [0,1]
a [0,1]
Operation:
(f) dest,
(f) dest
Operation:
Status Affected:
N, Z
(f) dest,
(f) C,
(C) dest
Status Affected:
C, N, Z
Encoding:
0100
Description:
f {,d {,a}}
01da
ffff
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Rotate Right f through Carry
Encoding:
0011
Description:
register f
Words:
1
Cycles:
1
00da
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
RLNCF
Before Instruction
REG
=
After Instruction
REG
=
DS40001365F-page 298
Words:
1
Cycles:
1
0101 0111
ffff
register f
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
RRCF
REG, 0, 0
REG, 1, 0
1010 1011
ffff
The contents of register ‘f’ are rotated
one bit to the right through the CARRY
flag. If ‘d’ is ‘0’, the result is placed in W.
If ‘d’ is ‘1’, the result is placed back in
register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
C
Q Cycle Activity:
Example:
f {,d {,a}}
Example:
Before Instruction
REG
=
C
=
After Instruction
REG
=
W
=
C
=
1110 0110
0
1110 0110
0111 0011
0
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
RRNCF
Rotate Right f (No Carry)
SETF
Syntax:
RRNCF
Syntax:
SETF
Operands:
0 f 255
d [0,1]
a [0,1]
Operands:
0 f 255
a [0,1]
Operation:
FFh f
Operation:
(f) dest,
(f) dest
Status Affected:
None
Status Affected:
f {,d {,a}}
Encoding:
N, Z
Encoding:
0100
Description:
00da
ffff
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
register f
Words:
1
Cycles:
1
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
RRNCF
Before Instruction
REG
=
After Instruction
REG
=
Example 2:
f {,a}
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
Q Cycle Activity:
Example 1:
Set f
SETF
Before Instruction
REG
After Instruction
REG
REG, 1
=
5Ah
=
FFh
REG, 1, 0
1101 0111
1110 1011
RRNCF
REG, 0, 0
Before Instruction
W
=
REG
=
After Instruction
?
1101 0111
=
=
1110 1011
1101 0111
W
REG
2009-2016 Microchip Technology Inc.
DS40001365F-page 299
PIC18(L)F1XK22
SLEEP
Enter Sleep mode
SUBFWB
Syntax:
SLEEP
Syntax:
SUBFWB
Operands:
None
Operands:
Operation:
00h WDT,
0 WDT postscaler,
1 TO,
0 PD
0 f 255
d [0,1]
a [0,1]
Operation:
(W) – (f) – (C) dest
Status Affected:
N, OV, C, DC, Z
Status Affected:
TO, PD
Encoding:
0000
Encoding:
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
0101
Q1
Q2
Q3
Q4
Decode
No
operation
Process
Data
Go to
Sleep
SLEEP
Before Instruction
TO =
?
PD =
?
After Instruction
1†
TO =
0
PD =
† If WDT causes wake-up, this bit is cleared.
DS40001365F-page 300
f {,d {,a}}
01da
ffff
ffff
Description:
Subtract register ‘f’ and CARRY flag
(borrow) from W (2’s complement
method). If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is ‘1’, the result is stored in
register ‘f’ (default).
If ‘a’ 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 24.2.3
“Byte-Oriented and Bit-Oriented
Instructions in Indexed Literal Offset
Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Example:
Subtract f from W with borrow
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
SUBFWB
REG, 1, 0
Example 1:
Before Instruction
REG
=
3
W
=
2
C
=
1
After Instruction
REG
=
FF
W
=
2
C
=
0
Z
=
0
N
=
1 ; result is negative
SUBFWB
REG, 0, 0
Example 2:
Before Instruction
REG
=
2
W
=
5
C
=
1
After Instruction
REG
=
2
W
=
3
C
=
1
Z
=
0
N
=
0 ; result is positive
SUBFWB
REG, 1, 0
Example 3:
Before Instruction
REG
=
1
W
=
2
C
=
0
After Instruction
REG
=
0
W
=
2
C
=
1
Z
=
1 ; result is zero
N
=
0
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
SUBLW
Subtract W from literal
SUBWF
Syntax:
SUBLW k
Syntax:
SUBWF
Operands:
0 k 255
Operands:
Operation:
k – (W) W
Status Affected:
N, OV, C, DC, Z
0 f 255
d [0,1]
a [0,1]
Operation:
(f) – (W) dest
Status Affected:
N, OV, C, DC, Z
Encoding:
0000
Description
1000
kkkk
kkkk
W is subtracted from the 8-bit
literal ‘k’. The result is placed in W.
Words:
1
Cycles:
1
Subtract W from f
Encoding:
0101
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to W
Example 1:
Before Instruction
W
=
C
=
After Instruction
W
=
C
=
Z
=
N
=
Example 2:
Before Instruction
W
=
C
=
After Instruction
W
=
C
=
Z
=
N
=
Example 3:
Before Instruction
W
=
C
=
After Instruction
W
=
C
=
Z
=
N
=
SUBLW
02h
1
Cycles:
1
Q Cycle Activity:
02h
?
00h
1
; result is zero
1
0
SUBLW
ffff
Words:
01h
?
SUBLW
ffff
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 24.2.3
“Byte-Oriented and Bit-Oriented
Instructions in Indexed Literal Offset
Mode” for details.
02h
01h
1
; result is positive
0
0
11da
Description:
Q Cycle Activity:
Q1
f {,d {,a}}
02h
03h
?
FFh ; (2’s complement)
0
; result is negative
0
1
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
SUBWF
REG, 1, 0
Example 1:
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
=
C
=
Z
=
N
=
Example 2:
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
=
C
=
Z
=
N
=
Example 3:
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
=
C
=
Z
=
N
=
2009-2016 Microchip Technology Inc.
3
2
?
1
2
1
0
0
; result is positive
SUBWF
REG, 0, 0
2
2
?
2
0
1
1
0
SUBWF
; result is zero
REG, 1, 0
1
2
?
FFh ;(2’s complement)
2
0
; result is negative
0
1
DS40001365F-page 301
PIC18(L)F1XK22
SUBWFB
Subtract W from f with Borrow
SWAPF
Swap f
Syntax:
SUBWFB
Syntax:
SWAPF f {,d {,a}}
Operands:
0 f 255
d [0,1]
a [0,1]
Operands:
0 f 255
d [0,1]
a [0,1]
Operation:
(f) – (W) – (C) dest
Operation:
Status Affected:
N, OV, C, DC, Z
(f) dest,
(f) dest
Status Affected:
None
Encoding:
0101
Description:
f {,d {,a}}
10da
ffff
ffff
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q2
Read
register ‘f’
Example 1:
SUBWFB
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
=
C
=
Z
=
N
=
Example 2:
Q4
Write to
destination
(0001 1001)
(0000 1101)
0Ch
0Dh
1
0
0
(0000 1011)
(0000 1101)
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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
REG, 1, 0
19h
0Dh
1
0011
Example:
SWAPF
Before Instruction
REG
=
After Instruction
REG
=
REG, 1, 0
53h
35h
; result is positive
SUBWFB REG, 0, 0
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
=
C
=
Z
=
N
=
Example 3:
1Bh
1Ah
0
(0001 1011)
(0001 1010)
1Bh
00h
1
1
0
(0001 1011)
SUBWFB
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
C
Z
N
Q3
Process
Data
Encoding:
=
=
=
=
DS40001365F-page 302
; result is zero
REG, 1, 0
03h
0Eh
1
(0000 0011)
(0000 1101)
F5h
(1111 0100)
; [2’s comp]
(0000 1101)
0Eh
0
0
1
; result is negative
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TBLRD
Table Read
TBLRD
Table Read (Continued)
Syntax:
TBLRD ( *; *+; *-; +*)
Example1:
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;
Example2:
0000
0000
0000
TBLRD
=
=
=
55h
00A356h
34h
=
=
34h
00A357h
+* ;
Before Instruction
TABLAT
TBLPTR
MEMORY (01A357h)
MEMORY (01A358h)
After Instruction
TABLAT
TBLPTR
Status Affected: None
Encoding:
*+ ;
Before Instruction
TABLAT
TBLPTR
MEMORY (00A356h)
After Instruction
TABLAT
TBLPTR
=
=
=
=
AAh
01A357h
12h
34h
=
=
34h
01A358h
10nn
nn=0 *
=1 *+
=2 *=3 +*
Description:
This instruction is used to read the contents
of Program Memory (P.M.). To address the
program memory, a pointer called Table
Pointer (TBLPTR) is used.
The TBLPTR (a 21-bit pointer) points to
each byte in the program memory. TBLPTR
has a 2-Mbyte address range.
TBLPTR[0] = 0: Least Significant Byte
of Program Memory
Word
TBLPTR[0] = 1: Most Significant Byte
of Program Memory
Word
The TBLRD instruction can modify the value
of TBLPTR as follows:
• no change
• post-increment
• post-decrement
• pre-increment
Words:
1
Cycles:
2
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
No
operation
No
operation
No
operation
No operation
(Read Program
Memory)
No
operation
No operation
(Write TABLAT)
2009-2016 Microchip Technology Inc.
DS40001365F-page 303
PIC18(L)F1XK22
TBLWT
Table Write
TBLWT
Table Write (Continued)
Syntax:
TBLWT ( *; *+; *-; +*)
Example1:
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:
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:
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
eight holding registers the TABLAT is written to. The holding registers are used to
program the contents of Program
Memory (P.M.). (Refer to Section 4.0
“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
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
Q Cycle Activity:
Q1
Decode
Q2
Q3
Q4
No
No
No
operation operation operation
No
No
No
No
operation operation operation operation
(Read
(Write to
TABLAT)
Holding
Register )
DS40001365F-page 304
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TSTFSZ
Test f, skip if 0
XORLW
Syntax:
TSTFSZ f {,a}
Syntax:
XORLW k
Operands:
0 f 255
a [0,1]
Operands:
0 k 255
Operation:
(W) .XOR. k W
Operation:
skip if f = 0
Status Affected:
N, Z
Status Affected:
None
Encoding:
Encoding:
0110
Description:
Exclusive OR literal with W
011a
ffff
ffff
If ‘f’ = 0, the next instruction fetched
during the current instruction execution
is discarded and a NOP is executed,
making this a 2-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 24.2.3 “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.
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
=
After Instruction
W
=
B5h
1Ah
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
No
operation
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
If skip:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example:
HERE
NZERO
ZERO
Before Instruction
PC
After Instruction
If CNT
PC
If CNT
PC
TSTFSZ
:
:
CNT, 1
=
Address (HERE)
=
=
=
00h,
Address (ZERO)
00h,
Address (NZERO)
2009-2016 Microchip Technology Inc.
DS40001365F-page 305
PIC18(L)F1XK22
XORWF
Exclusive OR W with f
Syntax:
XORWF
Operands:
0 f 255
d [0,1]
a [0,1]
Operation:
(W) .XOR. (f) dest
Status Affected:
N, Z
Encoding:
0001
f {,d {,a}}
10da
ffff
ffff
Description:
Exclusive OR the contents of W with
register ‘f’. If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ 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 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
XORWF
Before Instruction
REG
=
W
=
After Instruction
REG
=
W
=
DS40001365F-page 306
REG, 1, 0
AFh
B5h
1Ah
B5h
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
24.2
A summary of the instructions in the extended
instruction set is provided in Table 24-3. Detailed
descriptions are provided in Section 24.2.2
“Extended Instruction Set”. The opcode field
descriptions in Table 24-1 (page 266) apply to both the
standard and extended PIC18 instruction sets.
Extended Instruction Set
In addition to the standard 75 instructions of the PIC18
instruction set, PIC18(L)F1XK22 devices also provide
an optional extension to the core CPU functionality.
The added features include eight additional
instructions that augment indirect and indexed
addressing operations and the implementation of
Indexed Literal Offset Addressing mode for many of the
standard PIC18 instructions.
Note:
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 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.
24.2.1
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. MPASM™ Assembler will flag an
error if it determines that an index or offset value is not
bracketed.
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:
When the extended instruction set is enabled, brackets
are also used to indicate index arguments in byteoriented and bit-oriented instructions. This is in addition
to other changes in their syntax. For more details, see
Section 24.2.3.1 “Extended Instruction Syntax with
Standard PIC18 Commands”.
• 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
TABLE 24-3:
The instruction set extension and the
Indexed Literal Offset Addressing mode
were designed for optimizing applications
written in C; the user may likely never use
these instructions directly in assembler.
The syntax for these commands is
provided as a reference for users who
may be reviewing code that has been
generated by a compiler.
Note:
In the past, square brackets have been
used to denote optional arguments in the
PIC18 and earlier instruction sets. In this
text and going forward, optional
arguments are denoted by braces (“{ }”).
EXTENSIONS TO THE PIC18 INSTRUCTION SET
Mnemonic,
Operands
ADDFSR
ADDULNK
CALLW
MOVSF
f, k
k
MOVSS
zs, zd
PUSHL
k
SUBFSR
SUBULNK
f, k
k
zs, fd
16-Bit Instruction Word
Description
Cycles
MSb
Add literal to FSR
Add literal to FSR2 and return
Call subroutine using WREG
Move zs (source) to 1st word
2nd word
fd (destination)
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
2009-2016 Microchip Technology Inc.
1
2
2
2
LSb
Status
Affected
1000
1000
0000
1011
ffff
1011
xxxx
1010
ffkk
11kk
0001
0zzz
ffff
1zzz
xzzz
kkkk
kkkk
kkkk
0100
zzzz
ffff
zzzz
zzzz
kkkk
None
None
None
None
1
1110
1110
0000
1110
1111
1110
1111
1110
1
2
1110
1110
1001
1001
ffkk
11kk
kkkk
kkkk
None
None
2
None
None
DS40001365F-page 307
PIC18(L)F1XK22
24.2.2
EXTENDED INSTRUCTION SET
ADDFSR
Add Literal to FSR
ADDULNK
Syntax:
ADDFSR f, k
Syntax:
ADDULNK k
Operands:
0 k 63
f [ 0, 1, 2 ]
Operands:
0 k 63
Operation:
FSR(f) + k FSR(f)
Status Affected:
None
Encoding:
1110
Add Literal to FSR2 and Return
FSR2 + k FSR2,
Operation:
(TOS) PC
Status Affected:
1000
ffkk
kkkk
Description:
The 6-bit literal ‘k’ is added to the
contents of the FSR specified by ‘f’.
Words:
1
Cycles:
1
None
Encoding:
1110
Q1
Q2
Q3
Q4
Read
literal ‘k’
Process
Data
Write to
FSR
Example:
ADDFSR 2, 23h
Before Instruction
FSR2
=
03FFh
After Instruction
FSR2
=
0422h
kkkk
Words:
1
Cycles:
2
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to
FSR
No
Operation
No
Operation
No
Operation
No
Operation
Example:
Note:
11kk
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.
Q Cycle Activity:
Decode
1000
Description:
ADDULNK 23h
Before Instruction
FSR2
=
PC
=
03FFh
0100h
After Instruction
FSR2
=
PC
=
0422h
(TOS)
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).
DS40001365F-page 308
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
CALLW
Subroutine Call Using WREG
MOVSF
Syntax:
CALLW
Syntax:
MOVSF [zs], fd
Operands:
None
Operands:
Operation:
(PC + 2) TOS,
(W) PCL,
(PCLATH) PCH,
(PCLATU) PCU
0 zs 127
0 fd 4095
Operation:
((FSR2) + zs) fd
Status Affected:
None
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
Move Indexed to f
Encoding:
1st word (source)
2nd word (destin.)
Q1
Q2
Q3
Q4
Read
WREG
PUSH PC to
stack
No
operation
No
operation
No
operation
No
operation
No
operation
HERE
Before Instruction
PC
=
PCLATH =
PCLATU =
W
=
After Instruction
PC
=
TOS
=
PCLATH =
PCLATU =
W
=
2
Cycles:
2
Q Cycle Activity:
Q1
Decode
address (HERE)
10h
00h
06h
2009-2016 Microchip Technology Inc.
zzzzs
ffffd
Words:
CALLW
001006h
address (HERE + 2)
10h
00h
06h
0zzz
ffff
The contents of the source register are
moved to destination register ‘fd’. The
actual address of the source register is
determined by adding the 7-bit literal
offset ‘zs’ in the first word to the value of
FSR2. The address of the destination
register is specified by the 12-bit literal
‘fd’ in the second word. Both addresses
can be anywhere in the 4096-byte data
space (000h to FFFh).
The MOVSF instruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register.
If the resultant source address points to
an indirect addressing register, the
value returned will be 00h.
Decode
Example:
1011
ffff
Description:
Q Cycle Activity:
Decode
1110
1111
Q2
Q3
Determine
Determine
source addr source addr
No
operation
No
operation
No dummy
read
Example:
MOVSF
Before Instruction
FSR2
Contents
of 85h
REG2
After Instruction
FSR2
Contents
of 85h
REG2
Q4
Read
source reg
Write
register ‘f’
(dest)
[05h], REG2
=
80h
=
=
33h
11h
=
80h
=
=
33h
33h
DS40001365F-page 309
PIC18(L)F1XK22
MOVSS
Move Indexed to Indexed
PUSHL
Syntax:
Syntax:
PUSHL k
Operands:
MOVSS [zs], [zd]
0 zs 127
0 zd 127
Operands:
0k 255
Operation:
((FSR2) + zs) ((FSR2) + zd)
Operation:
k (FSR2),
FSR2 – 1 FSR2
Status Affected:
None
Status Affected:
None
Encoding:
1st word (source)
2nd word (dest.)
Description
1110
1111
1011
xxxx
1zzz
xzzz
zzzzs
zzzzd
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
Decode
Decode
Example:
Q2
Q3
Determine
Determine
source addr source addr
Determine
dest addr
Determine
dest addr
Store Literal at FSR2, Decrement FSR2
Encoding:
1110
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
Memory (01ECh)
=
=
01ECh
00h
After Instruction
FSR2H:FSR2L
Memory (01ECh)
=
=
01EBh
08h
Q4
Read
source reg
Write
to dest reg
MOVSS [05h], [06h]
Before Instruction
FSR2
Contents
of 85h
Contents
of 86h
After Instruction
FSR2
Contents
of 85h
Contents
of 86h
DS40001365F-page 310
=
80h
=
33h
=
11h
=
80h
=
33h
=
33h
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
SUBFSR
Subtract Literal from FSR
SUBULNK
Syntax:
SUBFSR f, k
Syntax:
SUBULNK k
Operands:
0 k 63
Operands:
0 k 63
f [ 0, 1, 2 ]
Operation:
Operation:
FSR(f) – k FSRf
Status Affected:
None
Encoding:
1110
FSR2 – k FSR2
(TOS) PC
Status Affected: None
1001
ffkk
kkkk
Description:
The 6-bit literal ‘k’ is subtracted from
the contents of the FSR specified by
‘f’.
Words:
1
Cycles:
1
Encoding:
1110
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
SUBFSR 2, 23h
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:
Example:
Subtract Literal from FSR2 and Return
Q Cycle Activity:
Before Instruction
FSR2
=
Q1
Q2
Q3
Q4
03FFh
Decode
After Instruction
FSR2
=
Read
register ‘f’
Process
Data
Write to
destination
03DCh
No
Operation
No
Operation
No
Operation
No
Operation
Example:
2009-2016 Microchip Technology Inc.
SUBULNK 23h
Before Instruction
FSR2
=
PC
=
03FFh
0100h
After Instruction
FSR2
=
PC
=
03DCh
(TOS)
DS40001365F-page 311
PIC18(L)F1XK22
24.2.3
Note:
BYTE-ORIENTED AND
BIT-ORIENTED INSTRUCTIONS IN
INDEXED LITERAL OFFSET MODE
Enabling the PIC18 instruction set
extension may cause legacy applications
to behave erratically or fail entirely.
In addition to eight new commands in the extended set,
enabling the extended instruction set also enables
Indexed Literal Offset Addressing mode (Section 3.5.1
“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
embedded 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 bitoriented 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 24.2.3.1
“Extended Instruction Syntax with Standard PIC18
Commands”).
24.2.3.1
Extended Instruction Syntax with
Standard PIC18 Commands
When the extended instruction set is enabled, the file
register argument, ‘f’, in the standard byte-oriented and
bit-oriented commands is replaced with the literal offset
value, ‘k’. As already noted, this occurs only when ‘f’ is
less than or equal to 5Fh. When an offset value is used,
it must be indicated by square brackets (“[ ]”). As with
the extended instructions, the use of brackets indicates
to the compiler that the value is to be interpreted as an
index or an offset. Omitting the brackets, or using a
value greater than 5Fh within brackets, will generate an
error in the MPASM™ assembler.
If the index argument is properly bracketed for Indexed
Literal Offset Addressing, the Access RAM argument is
never specified; it will automatically be assumed to be
‘0’. This is in contrast to standard operation (extended
instruction set disabled) when ‘a’ is set on the basis of
the target address. Declaring the Access RAM bit in
this mode will also generate an error in the MPASM
assembler.
The destination argument, ‘d’, functions as before.
In the latest versions of the MPASM assembler,
language support for the extended instruction set must
be explicitly invoked. This is done with either the
command line option, /y, or the PE directive in the
source listing.
24.2.4
CONSIDERATIONS WHEN
ENABLING THE EXTENDED
INSTRUCTION SET
It is important to note that the extensions to the
instruction 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.
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
register. Users who are accustomed to the PIC18
programming must keep in mind that, when the
extended instruction set is enabled, register addresses
of 5Fh or less are used for Indexed Literal Offset
Addressing.
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.
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.
When porting an application to the PIC18(L)F1XK22, 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.
DS40001365F-page 312
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
ADDWF
ADD W to Indexed
(Indexed Literal Offset mode)
BSF
Bit Set Indexed
(Indexed Literal Offset mode)
Syntax:
ADDWF
Syntax:
BSF [k], b
Operands:
0 k 95
d [0,1]
Operands:
0 f 95
0b7
Operation:
(W) + ((FSR2) + k) dest
Operation:
1 ((FSR2) + k)
Status Affected:
N, OV, C, DC, Z
Status Affected:
None
Encoding:
[k] {,d}
0010
Description:
01d0
kkkk
kkkk
The contents of W are added to the
contents of the register indicated by
FSR2, offset by the value ‘k’.
If ‘d’ is ‘0’, the result is stored in W. If ‘d’
is ‘1’, the result is stored back in
register ‘f’ (default).
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:
Words:
1
Q1
Q2
Q3
Q4
Cycles:
1
Decode
Read
register ‘f’
Process
Data
Write to
destination
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read ‘k’
Process
Data
Write to
destination
Example:
ADDWF
[OFST] , 0
Before Instruction
W
OFST
FSR2
Contents
of 0A2Ch
After Instruction
W
Contents
of 0A2Ch
=
=
=
17h
2Ch
0A00h
=
20h
=
37h
=
20h
Example:
BSF
Before Instruction
FLAG_OFST
FSR2
Contents
of 0A0Ah
After Instruction
Contents
of 0A0Ah
[FLAG_OFST], 7
=
=
0Ah
0A00h
=
55h
=
D5h
SETF
Set Indexed
(Indexed Literal Offset mode)
Syntax:
SETF [k]
Operands:
0 k 95
Operation:
FFh ((FSR2) + k)
Status Affected:
None
Encoding:
0110
1000
kkkk
kkkk
Description:
The contents of the register indicated by
FSR2, offset by ‘k’, are set to FFh.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read ‘k’
Process
Data
Write
register
Example:
SETF
Before Instruction
OFST
FSR2
Contents
of 0A2Ch
After Instruction
Contents
of 0A2Ch
2009-2016 Microchip Technology Inc.
[OFST]
=
=
2Ch
0A00h
=
00h
=
FFh
DS40001365F-page 313
PIC18(L)F1XK22
24.2.5
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 PIC18(L)F1XK22 family of devices. This
includes the MPLAB® C18 C compiler, MPASM
assembly
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 accompanying
their development systems for the appropriate
information.
DS40001365F-page 314
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
25.0
DEVELOPMENT SUPPORT
The PIC® microcontrollers (MCU) and dsPIC® digital
signal controllers (DSC) are supported with a full range
of software and hardware development tools:
• Integrated Development Environment
- MPLAB® X IDE Software
• Compilers/Assemblers/Linkers
- MPLAB XC Compiler
- MPASMTM Assembler
- MPLINKTM Object Linker/
MPLIBTM Object Librarian
- MPLAB Assembler/Linker/Librarian for
Various Device Families
• Simulators
- MPLAB X SIM Software Simulator
• Emulators
- MPLAB REAL ICE™ In-Circuit Emulator
• In-Circuit Debuggers/Programmers
- MPLAB ICD 3
- PICkit™ 3
• Device Programmers
- MPLAB PM3 Device Programmer
• Low-Cost Demonstration/Development Boards,
Evaluation Kits and Starter Kits
• Third-party development tools
25.1
MPLAB X Integrated Development
Environment Software
The MPLAB X IDE is a single, unified graphical user
interface for Microchip and third-party software, and
hardware development tool that runs on Windows®,
Linux and Mac OS® X. Based on the NetBeans IDE,
MPLAB X IDE is an entirely new IDE with a host of free
software components and plug-ins for highperformance application development and debugging.
Moving between tools and upgrading from software
simulators to hardware debugging and programming
tools is simple with the seamless user interface.
With complete project management, visual call graphs,
a configurable watch window and a feature-rich editor
that includes code completion and context menus,
MPLAB X IDE is flexible and friendly enough for new
users. With the ability to support multiple tools on
multiple projects with simultaneous debugging, MPLAB
X IDE is also suitable for the needs of experienced
users.
Feature-Rich Editor:
• Color syntax highlighting
• Smart code completion makes suggestions and
provides hints as you type
• Automatic code formatting based on user-defined
rules
• Live parsing
User-Friendly, Customizable Interface:
• Fully customizable interface: toolbars, toolbar
buttons, windows, window placement, etc.
• Call graph window
Project-Based Workspaces:
•
•
•
•
Multiple projects
Multiple tools
Multiple configurations
Simultaneous debugging sessions
File History and Bug Tracking:
• Local file history feature
• Built-in support for Bugzilla issue tracker
2009-2016 Microchip Technology Inc.
DS40001365F-page 315
PIC18(L)F1XK22
25.2
MPLAB XC Compilers
The MPLAB XC Compilers are complete ANSI C
compilers for all of Microchip’s 8, 16, and 32-bit MCU
and DSC devices. These compilers provide powerful
integration capabilities, superior code optimization and
ease of use. MPLAB XC Compilers run on Windows,
Linux or MAC OS X.
For easy source level debugging, the compilers provide
debug information that is optimized to the MPLAB X
IDE.
The free MPLAB XC Compiler editions support all
devices and commands, with no time or memory
restrictions, and offer sufficient code optimization for
most applications.
MPLAB XC Compilers include an assembler, linker and
utilities. 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. MPLAB XC Compiler uses the
assembler to produce its object file. Notable features of
the assembler include:
•
•
•
•
•
•
Support for the entire device instruction set
Support for fixed-point and floating-point data
Command-line interface
Rich directive set
Flexible macro language
MPLAB X IDE compatibility
25.3
MPASM Assembler
The MPASM Assembler is a full-featured, universal
macro assembler for PIC10/12/16/18 MCUs.
The MPASM Assembler generates relocatable object
files for the MPLINK Object Linker, Intel® standard HEX
files, MAP files to detail memory usage and symbol
reference, absolute LST files that contain source lines
and generated machine code, and COFF files for
debugging.
The MPASM Assembler features include:
25.4
MPLINK Object Linker/
MPLIB Object Librarian
The MPLINK Object Linker combines relocatable
objects created by the MPASM Assembler. 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
25.5
MPLAB Assembler, Linker and
Librarian for Various Device
Families
MPLAB Assembler produces relocatable machine
code from symbolic assembly language for PIC24,
PIC32 and dsPIC DSC devices. MPLAB XC Compiler
uses the assembler to produce its object file. The
assembler generates relocatable object files that can
then be archived or linked with other relocatable object
files and archives to create an executable file. Notable
features of the assembler include:
•
•
•
•
•
•
Support for the entire device instruction set
Support for fixed-point and floating-point data
Command-line interface
Rich directive set
Flexible macro language
MPLAB X IDE compatibility
• Integration into MPLAB X IDE projects
• User-defined macros to streamline
assembly code
• Conditional assembly for multipurpose
source files
• Directives that allow complete control over the
assembly process
DS40001365F-page 316
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
25.6
MPLAB X SIM Software Simulator
The MPLAB X SIM Software Simulator allows code
development in a PC-hosted environment by
simulating 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 X SIM Software Simulator fully supports
symbolic debugging using the MPLAB XC Compilers,
and the MPASM and MPLAB 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.
25.7
MPLAB REAL ICE In-Circuit
Emulator System
The 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 all 8, 16 and 32-bit MCU, and DSC devices
with the easy-to-use, powerful graphical user interface of
the MPLAB X IDE.
The emulator is connected to the design engineer’s
PC using a high-speed USB 2.0 interface and is
connected to the target with either a connector
compatible with in-circuit debugger systems (RJ-11)
or with the new high-speed, noise tolerant, LowVoltage Differential Signal (LVDS) interconnection
(CAT5).
The emulator is field upgradable through future firmware
downloads in MPLAB X IDE. MPLAB REAL ICE offers
significant advantages over competitive emulators
including full-speed emulation, run-time variable
watches, trace analysis, complex breakpoints, logic
probes, a ruggedized probe interface and long (up to
three meters) interconnection cables.
2009-2016 Microchip Technology Inc.
25.8
MPLAB ICD 3 In-Circuit Debugger
System
The MPLAB ICD 3 In-Circuit Debugger System is
Microchip’s most cost-effective, high-speed hardware
debugger/programmer for Microchip Flash DSC and
MCU devices. It debugs and programs PIC Flash
microcontrollers and dsPIC DSCs with the powerful,
yet easy-to-use graphical user interface of the MPLAB
IDE.
The MPLAB ICD 3 In-Circuit Debugger probe is
connected to the design engineer’s PC using a highspeed USB 2.0 interface and is connected to the target
with a connector compatible with the MPLAB ICD 2 or
MPLAB REAL ICE systems (RJ-11). MPLAB ICD 3
supports all MPLAB ICD 2 headers.
25.9
PICkit 3 In-Circuit Debugger/
Programmer
The MPLAB PICkit 3 allows debugging and
programming of PIC and dsPIC Flash microcontrollers
at a most affordable price point using the powerful
graphical user interface of the MPLAB IDE. The
MPLAB PICkit 3 is connected to the design engineer’s
PC using a full-speed USB interface and can be
connected to the target via a Microchip debug (RJ-11)
connector (compatible with MPLAB ICD 3 and MPLAB
REAL ICE). The connector uses two device I/O pins
and the Reset line to implement in-circuit debugging
and In-Circuit Serial Programming™ (ICSP™).
25.10 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
modular, detachable socket assembly to support
various package types. The ICSP cable assembly is
included as a standard item. In Stand-Alone mode, the
MPLAB PM3 Device Programmer can read, verify and
program PIC devices without a PC connection. It can
also set code protection in this mode. The MPLAB PM3
connects to the host PC via an RS-232 or USB cable.
The MPLAB PM3 has high-speed communications and
optimized algorithms for quick programming of large
memory devices, and incorporates an MMC card for file
storage and data applications.
DS40001365F-page 317
PIC18(L)F1XK22
25.11 Demonstration/Development
Boards, Evaluation Kits, and
Starter Kits
A wide variety of demonstration, development and
evaluation boards for various PIC MCUs and dsPIC
DSCs allows quick application development on fully
functional 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.
25.12 Third-Party Development Tools
Microchip also offers a great collection of tools from
third-party vendors. These tools are carefully selected
to offer good value and unique functionality.
• Device Programmers and Gang Programmers
from companies, such as SoftLog and CCS
• Software Tools from companies, such as Gimpel
and Trace Systems
• Protocol Analyzers from companies, such as
Saleae and Total Phase
• Demonstration Boards from companies, such as
MikroElektronika, Digilent® and Olimex
• Embedded Ethernet Solutions from companies,
such as EZ Web Lynx, WIZnet and IPLogika®
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™
demonstration/development board series of circuits,
Microchip has a line of evaluation kits and
demonstration software for analog filter design,
KEELOQ® security ICs, CAN, IrDA®, PowerSmart
battery management, SEEVAL® evaluation system,
Sigma-Delta ADC, flow rate sensing, plus many more.
Also available are starter kits that contain everything
needed to experience the specified device. This usually
includes a single application and debug capability, all
on one board.
Check the Microchip web page (www.microchip.com)
for the complete list of demonstration, development
and evaluation kits.
DS40001365F-page 318
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
26.0
ELECTRICAL SPECIFICATIONS
26.1
Absolute Maximum Ratings(†)
Ambient temperature under bias...................................................................................................... -40°C to +125°C
Storage temperature ........................................................................................................................ -65°C to +150°C
Voltage on pins with respect to VSS
on VDD pin
PIC18F1XK22 ........................................................................................................... -0.3V to +6.5V
PIC18LF1XK22 ......................................................................................................... -0.3V to +4.0V
on MCLR pin ........................................................................................................................... -0.3V to +9.0V
on all other pins ............................................................................................................ -0.3V to (VDD + 0.3V)
Maximum current(1)
on VSS pin
-40°C TA +85°C, Industrial ............................................................................................. 250 mA
-40°C TA +125°C, Extended ............................................................................................. 85 mA
on VDD pin
-40°C TA +85°C,Industrial .............................................................................................. 250 mA
-40°C TA +125°C, Extended ............................................................................................. 85 mA
sunk by all ports................................................................................................................................... 250 mA
sourced by all ports ............................................................................................................................. 250 mA
Maximum output current
sunk by any I/O pin.............................................................................................................................. 50 mA
sourced by any I/O pin ....................................................................................................................... 50 mA
Clamp current, IK (VPIN < 0 or VPIN > VDD) ................................................................................................... 20 mA
Total power dissipation(2) ............................................................................................................................... 800 mW
Note 1:
2:
Maximum current rating requires even load distribution across I/O pins. Maximum current rating may be
limited by the device package power dissipation characterizations, see Table 26-8 to calculate device
specifications.
Power dissipation is calculated as follows:
PDIS = VDD x {IDD – ΣIOH} + Σ{VDD – VOH) x IOH} + Σ(VOL x IOI).
† NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. This is a stress rating only and functional operation of the device at those or any other conditions above those
indicated in the operation listings of this specification is not implied. Exposure above maximum rating conditions for
extended periods may affect device reliability.
2009-2016 Microchip Technology Inc.
DS40001365F-page 319
PIC18(L)F1XK22
26.2
Standard Operating Conditions
The standard operating conditions for any device are defined as:
Operating Voltage:
Operating Temperature:
VDDMIN VDD VDDMAX
TA_MIN TA TA_MAX
VDD — Operating Supply Voltage(1)
PIC18LF1XK22
VDDMIN (Fosc 16 MHz).......................................................................................................... +1.8V
VDDMIN (Fosc 20 MHz).......................................................................................................... +2.0V
VDDMIN (Fosc 64 MHz).......................................................................................................... +3.0V
VDDMAX .................................................................................................................................... +3.6V
PIC18F1XK22
VDDMIN (Fosc 20 MHz).......................................................................................................... +2.3V
VDDMIN (Fosc 64 MHz).......................................................................................................... +3.0V
VDDMAX .................................................................................................................................... +5.5V
TA — Operating Ambient Temperature Range
Industrial Temperature
TA_MIN ...................................................................................................................................... -40°C
TA_MAX .................................................................................................................................... +85°C
Extended Temperature
TA_MIN ...................................................................................................................................... -40°C
TA_MAX .................................................................................................................................. +125°C
Note 1:
See Parameter D001, DC Characteristics: Supply Voltage.
DS40001365F-page 320
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 26-1:
PIC18F1XK22 VOLTAGE FREQUENCY GRAPH, -40°C TA +85°C
5.5
VDD (V)
3.6
3.0
2.3
0
10
20
40
48
64
Frequency (MHz)
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
2: Refer to Table 26-13 for each Oscillator mode’s supported frequencies.
FIGURE 26-2:
PIC18F1XK22 VOLTAGE FREQUENCY GRAPH, -40°C TA +125°C
5.5
VDD (V)
3.6
3.0
2.3
0
10
20
40
48
64
Frequency (MHz)
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
2: Refer to Table 26-13 for each Oscillator mode’s supported frequencies.
2009-2016 Microchip Technology Inc.
DS40001365F-page 321
PIC18(L)F1XK22
FIGURE 26-3:
PIC18LF1XK22 VOLTAGE FREQUENCY GRAPH, -40°C TA +85°C
VDD (V)
3.6
3.0
2.0
1.8
0
10
16
20
40
48
64
Frequency (MHz)
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
2: Refer to Table 26-13 for each Oscillator mode’s supported frequencies.
FIGURE 26-4:
PIC18LF1XK22 VOLTAGE FREQUENCY GRAPH, -40°C TA +125°C
VDD (V)
3.6
3.0
2.0
1.8
0
10
16
20
40
48
64
Frequency (MHz)
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
2: Refer to Table 26-13 for each Oscillator mode’s supported frequencies.
DS40001365F-page 322
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 26-5:
HFINTOSC FREQUENCY ACCURACY OVER DEVICE VDD AND TEMPERATURE
125
± 5%
Temperature (°C)
85
± 3%
60
25
± 2%
0
-20
-40
1.8
± 5%
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
2009-2016 Microchip Technology Inc.
DS40001365F-page 323
PIC18(L)F1XK22
26.3
DC Characteristics
TABLE 26-1:
SUPPLY VOLTAGE
PIC18LF1XK22
Standard Operating Conditions (unless otherwise stated)
PIC18F1XK22
Standard Operating Conditions (unless otherwise stated)
Param.
No.
D001
Sym.
VDD
Characteristic
VDR
Max.
Units
Conditions
PIC18LF1XK22
1.8
2.0
3.0
3.0
—
—
—
—
3.6
3.6
3.6
3.6
V
V
V
V
FOSC 16 MHz
FOSC 20 MHz
FOSC 64 MHz 85°C
FOSC 48 MHz 125°C
PIC18F1XK22
2.3
3.0
3.0
—
—
—
5.5
5.5
5.5
V
V
V
FOSC 20 MHz
FOSC 64 MHz 85°C
FOSC 48 MHz 125°C
RAM Data Retention Voltage(1)
D002*
D004*
Typ.†
Supply Voltage
D001
D002*
Min.
PIC18LF1XK22
1.5
—
—
V
Device in Sleep mode
PIC18F1XK22
1.7
—
—
V
Device in Sleep mode
V
VPOR*
Power-on Reset Release Voltage
—
1.6
—
VPORR*
Power-on Reset Rearm Voltage
—
0.8
—
V
SVDD
VDD Rise Rate to ensure internal
Power-on Reset signal
0.05
—
—
V/ms
*
†
These parameters are characterized but not tested.
Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
Note 1: This is the limit to which VDD can be lowered in Sleep mode without losing RAM data.
DS40001365F-page 324
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 26-6:
POR AND POR REARM WITH SLOW RISING VDD
VDD
VPOR
VPORR
VSS
NPOR
POR REARM
VSS
TVLOW(2)
Note 1:
2:
3:
TPOR(3)
When NPOR is low, the device is held in Reset.
TPOR 1 s typical.
TVLOW 2.7 s typical.
2009-2016 Microchip Technology Inc.
DS40001365F-page 325
PIC18(L)F1XK22
TABLE 26-2:
RC RUN SUPPLY CURRENT
PIC18LF1XK22
Standard Operating Conditions (unless otherwise stated)
PIC18F1XK22
Standard Operating Conditions (unless otherwise stated)
Param.
No.
D008
Device Characteristics
Typ.
Supply Current (IDD)(1, 2, 4, 5)
D008A
D008
D008A
D008B
Max.
Units
Conditions
6
9
A
-40°C
7
10
A
+25°C
8
14
A
+85°C
11
17
A
+125°C
11
15
A
-40°C
12
16
A
+25°C
13
25
A
+85°C
+125°C
17
28
A
22
45
A
-40°C
23
48
A
+25°C
25
50
A
+85°C
28
55
A
+125°C
25
50
A
-40°C
27
55
A
+25°C
30
60
A
+85°C
32
75
A
+125°C
30
55
A
-40°C
33
60
A
+25°C
37
65
A
+85°C
VDD = 1.8V
FOSC = 31 kHz(4)
(RC_RUN mode,
LFINTOSC source)
VDD = 3.0V
VDD = 2.3V
VDD = 3.0V
VDD = 5.0V
40
80
A
+125°C
D009
0.4
0.5
mA
-40°C to +125°C
VDD = 1.8V
D009A
0.6
0.8
mA
-40°C to +125°C
VDD = 3.0V
D009
0.45
0.55
mA
-40°C to +125°C
VDD = 2.3V
D009A
0.60
0.82
mA
-40°C to +125°C
VDD = 3.0V
D009B
0.80
1.0
mA
-40°C to +125°C
VDD = 5.0V
D010
1.9
2.5
mA
-40°C to +125°C
VDD = 1.8V
D010A
3.5
4.4
mA
-40°C to +125°C
VDD = 3.0V
D010
2.4
3.5
mA
-40°C to +125°C
VDD = 2.3V
D010A
3.5
4.6
mA
-40°C to +125°C
VDD = 3.0V
3.7
4.7
mA
-40°C to +125°C
VDD = 5.0V
D010B
*
Note 1:
2:
3:
4:
5:
FOSC = 31 kHz(4)
(RC_RUN mode,
LFINTOSC source)
FOSC = 1 MHz
(RC_RUN mode,
HFINTOSC source)
FOSC = 1 MHz
(RC_RUN mode,
HFINTOSC source)
FOSC = 16 MHz
(RC_RUN mode,
HF-INTOSC source)
FOSC = 16 MHz
(RC_RUN mode,
HF-INTOSC source)
These parameters are characterized but not tested.
The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from
rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT disabled.
The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading
and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current
consumption.
For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended
by the formula IR = VDD/2REXT (mA) with REXT in k
FVR and BOR are disabled.
When a single temperature range is provided for a parameter, the specification applies to both industrial and extended
temperature devices.
DS40001365F-page 326
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-3:
RC IDLE SUPPLY CURRENT
PIC18LF1XK22
Standard Operating Conditions (unless otherwise stated)
PIC18F1XK22
Standard Operating Conditions (unless otherwise stated)
Param.
No.
D011
Device Characteristics
Typ.
Max.
Units
Supply Current (IDD)(1, 2, 4, 5)
2
5
A
-40°C
2
6
A
+25°C
3
9
A
+85°C
8
11
A
+125°C
4
8
A
-40°C
4
10
A
+25°C
5
13
A
+85°C
+125°C
D011A
D011
D011A
D011B
Conditions
8
15
A
20
28
A
-40°C
21
35
A
+25°C
23
41
A
+85°C
24
50
A
+125°C
23
35
A
-40°C
25
40
A
+25°C
28
46
A
+85°C
30
65
A
+125°C
28
43
A
-40°C
30
48
A
+25°C
32
51
A
+85°C
VDD = 1.8V
FOSC = 31 kHz(4)
(RC_IDLE mode,
LFINTOSC source)
VDD = 3.0V
VDD = 2.3V
VDD = 3.0V
VDD = 5.0V
33
71
A
+125°C
D012
0.30
0.45
mA
-40°C to +125°C
VDD = 1.8V
D012A
0.45
0.60
mA
-40°C to +125°C
VDD = 3.0V
D012
0.32
0.45
mA
-40°C to +125°C
VDD = 2.3V
D012A
0.47
0.62
mA
-40°C to +125°C
VDD = 3.0V
D012B
0.63
0.78
mA
-40°C to +125°C
VDD = 5.0V
D013
0.89
1.20
mA
-40°C to +125°C
VDD = 1.8V
D013A
1.45
2.00
mA
-40°C to +125°C
VDD = 3.0V
D013
1.10
1.50
mA
-40°C to +125°C
VDD = 2.3V
D013A
1.45
2.00
mA
-40°C to +125°C
VDD = 3.0V
1.53
2.20
mA
-40°C to +125°C
VDD = 5.0V
D013B
*
Note 1:
2:
3:
4:
5:
FOSC = 31 kHz(4)
(RC_IDLE mode,
LFINTOSC source)
FOSC = 1 MHz
(RC_IDLE mode,
HF-INTOSC source)
FOSC = 1 MHz
(RC_IDLE mode,
HF-INTOSC source)
FOSC = 16 MHz
(RC_IDLE mode,
HF-INTOSC source)
FOSC = 16 MHz
(RC_IDLE mode,
HF-INTOSC source)
These parameters are characterized but not tested.
The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from
rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT disabled.
The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading
and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current
consumption.
For RC oscillator configurations, current through REXT is not included. The current through the resistor can be extended
by the formula IR = VDD/2REXT (mA) with REXT in k
FVR and BOR are disabled.
When a single temperature range is provided for a parameter, the specification applies to both industrial and extended
temperature devices.
2009-2016 Microchip Technology Inc.
DS40001365F-page 327
PIC18(L)F1XK22
TABLE 26-4:
PRIMARY RUN SUPPLY CURRENT
PIC18LF1XK22
Standard Operating Conditions (unless otherwise stated)
PIC18F1XK22
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Device Characteristics
Typ.
Max.
Units
Supply Current (IDD)(1, 2, 4, 5)
0.20
0.32
mA
-40°C to +125°C
VDD = 1.8V
0.27
0.39
mA
-40°C to +125°C
VDD = 3.0V
D014
.20
.32
mA
-40°C to +125°C
VDD = 2.3V
D014A
.27
.39
mA
-40°C to +125°C
VDD = 3.0V
D014B
.30
.42
mA
-40°C to +125°C
VDD = 5.0V
D015
1.7
2.6
mA
-40°C to +125°C
VDD = 1.8V
3.0
4.2
mA
-40°C to +125°C
VDD = 3.0V
D015
2.4
3.2
mA
-40°C to +125°C
VDD = 2.3V
D015A
3.0
4.2
mA
-40°C to +125°C
VDD = 3.0V
D015B
3.3
4.4
mA
-40°C to +125°C
VDD = 5.0V
11.5
14.0
mA
-40°C to +125°C
VDD = 3.0V
D016
11.9
14.4
mA
-40°C to +125°C
VDD = 2.3V
D016A
12.1
14.6
mA
-40°C to +125°C
VDD = 5.0V
D017
2.1
2.9
mA
-40°C to +125°C
VDD = 1.8V
3.1
4.0
mA
-40°C to +125°C
VDD = 3.0V
D017
2.1
2.9
mA
-40°C to +125°C
VDD = 2.3V
D017A
3.1
4.0
mA
-40°C to +125°C
VDD = 3.0V
D017B
3.3
4.5
mA
-40°C to +125°C
VDD = 5.0V
10
15
mA
-40°C to +125°C
VDD = 3.0V
D018
12.4
15.4
mA
-40°C to +125°C
VDD = 3.0V
D018A
12.6
15.6
mA
-40°C to +125°C
VDD = 5.0V
D014
D014A
D015A
Conditions
D016
D017A
D018
FOSC = 1 MHz
(PRI_RUN,
EC Med Osc)
FOSC = 1 MHz
(PRI_RUN,
EC Med Osc)
FOSC = 16 MHz
(PRI_RUN,
EC High Osc)
FOSC = 16 MHz
(PRI_RUN,
EC High Osc)
FOSC = 64 MHz
(PRI_RUN,
EC High Osc)
FOSC = 64 MHz
(PRI_RUN,
EC High Osc)
FOSC = 4 MHz
16 MHz Internal
(PRI_RUN HS+PLL)
FOSC = 4 MHz
16 MHz Internal
(PRI_RUN HS+PLL)
FOSC = 16 MHz
64 MHz Internal
(PRI_RUN HS+PLL)
FOSC = 16 MHz
64 MHz Internal
(PRI_RUN HS+PLL)
* These parameters are characterized but not tested.
Note 1: The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from
rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT disabled.
2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin
loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact
on the current consumption.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be
extended by the formula IR = VDD/2REXT (mA) with REXT in k
4: FVR and BOR are disabled.
5:
When a single temperature range is provided for a parameter, the specification applies to both industrial and extended
temperature devices.
DS40001365F-page 328
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-5:
PRIMARY IDLE SUPPLY CURRENT
PIC18LF1XK22
Standard Operating Conditions (unless otherwise stated)
PIC18F1XK22
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Device Characteristics
Typ.
Max.
Units
Supply Current (IDD)(1, 2, 4, 5)
70
105
A
-40°C to +125°C
VDD = 1.8V
140
180
A
-40°C to +125°C
VDD = 3.0V
D019
80
120
A
-40°C to +125°C
VDD = 2.3V
D019A
140
180
A
-40°C to +125°C
VDD = 3.0V
D019B
151
230
A
-40°C to +125°C
VDD = 5.0V
D020
1.0
1.8
mA
-40°C to +125°C
VDD = 1.8V
1.2
2.0
mA
-40°C to +125°C
VDD = 3.0V
D020
1.0
1.8
mA
-40°C to +125°C
VDD = 2.3V
D020A
1.2
2.0
mA
-40°C to +125°C
VDD = 3.0V
D020B
1.4
2.1
mA
-40°C to +125°C
VDD = 5.0V
5.0
7.0
mA
-40°C to +125°C
VDD = 3.0V
D021
5.2
6.2
mA
-40°C to +125°C
VDD = 3.0V
D021A
5.3
6.3
mA
-40°C to +125°C
VDD = 5.0V
D019
D019A
D020A
Conditions
D021
FOSC = 1 MHz
(PRI_IDLE mode,
EC Med Osc)
FOSC = 1 MHz
(PRI_IDLE mode,
EC Med Osc)
FOSC = 16 MHz
(PRI_IDLEmode,
EC High Osc)
FOSC = 16 MHz
(PRI_IDLEmode,
EC High Osc)
FOSC = 64 MHz
(PRI_IDLEmode,
EC High Osc)
FOSC = 64 MHz
(PRI_IDLEmode,
EC High Osc)
* These parameters are characterized but not tested.
Note 1: The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from
rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT disabled.
2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin
loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact
on the current consumption.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be
extended by the formula IR = VDD/2REXT (mA) with REXT in k
4:
5:
FVR and BOR are disabled.
When a single temperature range is provided for a parameter, the specification applies to both industrial and extended
temperature devices.
2009-2016 Microchip Technology Inc.
DS40001365F-page 329
PIC18(L)F1XK22
TABLE 26-6:
SECONDARY RUN SUPPLY CURRENT
PIC18LF1XK22
Standard Operating Conditions (unless otherwise stated)
PIC18F1XK22
Standard Operating Conditions (unless otherwise stated)
Param.
No.
D022
Device Characteristics
Supply Current (IDD)(1, 2, 4)
D022A
D022
D022A
D022B
*
Note 1:
2:
3:
4:
Typ.
Max.
Units
Conditions
6
9
A
-40°C
6
10
A
+25°C
7
14
A
+85°C
11
17
A
+125°C
11
15
A
-40°C
11
16
A
+25°C
12
25
A
+85°C
26
28
A
+125°C
22
65
A
-40°C
23
67
A
+25°C
25
69
A
+85°C
28
75
A
+125°C
25
70
A
-40°C
27
72
A
+25°C
30
74
A
+85°C
32
77
A
+125°C
30
75
A
-40°C
32
77
A
+25°C
34
79
A
+85°C
35
83
A
+125°C
VDD = 1.8V
FOSC = 32 kHz(3)
(SEC_RUN mode,
Timer1 as clock)
VDD = 3.0V
VDD = 2.3V
VDD = 3.0V
FOSC = 32 kHz(3)
(SEC_RUN mode,
Timer1 as clock)
VDD = 5.0V
These parameters are characterized but not tested.
The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from
rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT disabled.
The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin
loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact
on the current consumption.
For RC oscillator configurations, current through REXT is not included. The current through the resistor can be
extended by the formula IR = VDD/2REXT (mA) with REXT in k
FVR and BOR are disabled.
DS40001365F-page 330
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-7:
SECONDARY IDLE SUPPLY CURRENT
PIC18LF1XK22
Standard Operating Conditions (unless otherwise stated)
PIC18F1XK22
Standard Operating Conditions (unless otherwise stated)
Param.
No.
D023
Device Characteristics
Supply Current (IDD)(1, 2, 4)
D023A
D023
D023A
D023B
*
Note 1:
2:
3:
4:
Typ.
Max.
Units
Conditions
2
5
A
-40°C
2
5
A
+25°C
3
9
A
+85°C
8
11
A
+125°C
4
8
A
-40°C
5
10
A
+25°C
9
20
A
+85°C
20
23
A
+125°C
20
40
A
-40°C
21
41
A
+25°C
23
44
A
+85°C
24
47
A
+125°C
23
45
A
-40°C
25
47
A
+25°C
28
49
A
+85°C
30
52
A
+125°C
28
50
A
-40°C
30
54
A
+25°C
32
59
A
+85°C
33
62
A
+125°C
VDD = 1.8V
FOSC = 32 kHz(3)
(SEC_IDLE mode,
Timer1 as clock)
VDD = 3.0V
VDD = 2.3V
VDD = 3.0V
FOSC = 32 kHz(3)
(SEC_IDLE mode,
Timer1 as clock)
VDD = 5.0V
These parameters are characterized but not tested.
The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from
rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT disabled.
The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin
loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact
on the current consumption.
For RC oscillator configurations, current through REXT is not included. The current through the resistor can be
extended by the formula IR = VDD/2REXT (mA) with REXT in k
FVR and BOR are disabled.
2009-2016 Microchip Technology Inc.
DS40001365F-page 331
PIC18(L)F1XK22
TABLE 26-8:
POWER-DOWN CURRENT
PIC18LF1XK22
Standard Operating Conditions (unless otherwise stated)
PIC18F1XK22
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Device Characteristics
Power-down Base Current
Min.
Typ.†
Conditions
Max.
+85°C
Max.
+125°C
Units
VDD
Note
(IPD)(2)
D027
D027
—
0.034
1.0
9.0
A
1.8
—
0.071
2.0
10
A
3.0
—
17
40
55
A
2.3
—
18
43
65
A
3.0
—
20
45
80
A
5.0
—
.46
1.3
10
A
1.8
—
.74
3.0
11
A
3.0
—
18
44
60
A
2.3
—
21
46
70
A
3.0
WDT, BOR, FVR, T1OSC
disabled, all Peripherals Inactive
WDT, BOR, FVR and T1OSC
disabled, all Peripherals Inactive
Power-down Module Current
D028
D028
LPWDT Current(1)
LPWDT Current(1)
—
22
48
85
A
5.0
—
12
20
28
A
1.8
—
14
22
30
A
3.0
—
40
65
80
A
2.3
—
50
70
85
A
3.0
—
70
120
135
A
5.0
D030
—
12
17
23
A
3.0
BOR Current(1, 3)
D030
—
30
55
80
A
3.0
BOR Current(1, 3)
—
64
100
120
A
5.0
D031
—
.65
1.5
11
A
1.8
—
0.90
4.0
12
A
3.0
—
19
45
60
A
2.3
—
20
50
70
A
3.0
—
22
55
80
A
5.0
D029
D029
D031
*
†
Note 1:
2:
3:
4:
FVR Current (3)
FVR Current(3)
T1OSC Current(1)
T1OSC Current(1)
These parameters are characterized but not tested.
Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
The peripheral current is the sum of the base IDD or IPD and the additional current consumed when this peripheral is
enabled. The peripheral current can be determined by subtracting the base IDD or IPD current from this limit. Max
values should be used when calculating total current consumption.
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.
Fixed Voltage Reference is automatically enabled whenever the BOR is enabled.
A/D oscillator source is FRC.
DS40001365F-page 332
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-8:
POWER-DOWN CURRENT (CONTINUED)
PIC18LF1XK22
Standard Operating Conditions (unless otherwise stated)
PIC18F1XK22
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Device Characteristics
Min.
Conditions
Max.
+85°C
Max.
+125°C
Units
.7
1.0
9.0
A
Typ.†
VDD
Note
1.8
A/D Current(1, 4), no conversion in
progress
Power-down Module Current
D032
—
—
.8
3.0
10
A
3.0
D032
—
19
42
60
A
2.3
—
20
44
65
A
3.0
—
22
46
80
A
5.0
—
8
30
32
A
1.8
—
11
32
35
A
3.0
Comparator Current, low power
C1 and C2 enabled
—
23
55
65
A
2.3
Comparator Current, low power
—
31
65
75
A
3.0
—
33
75
95
A
5.0
D033A
—
44
110
160
A
1.8
—
65
130
165
A
3.0
Comparator Current, high power
C1 and C2 enabled
D033A
—
77
137
155
A
2.3
Comparator Current, high power
—
84
140
165
A
3.0
—
90
150
180
A
5.0
—
13
18
33
A
1.8
—
22
30
40
A
3.0
—
33
55
85
A
2.3
—
35
80
95
A
3.0
—
48
90
120
A
5.0
D033
D033
D034
D034
*
†
Note 1:
2:
3:
4:
A/D Current(1, 4), no conversion in
progress
C1 and C2 enabled
C1 and C2 enabled
FVR Current
FVR Current
These parameters are characterized but not tested.
Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
The peripheral current is the sum of the base IDD or IPD and the additional current consumed when this peripheral is
enabled. The peripheral current can be determined by subtracting the base IDD or IPD current from this limit. Max
values should be used when calculating total current consumption.
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.
Fixed Voltage Reference is automatically enabled whenever the BOR is enabled.
A/D oscillator source is FRC.
2009-2016 Microchip Technology Inc.
DS40001365F-page 333
PIC18(L)F1XK22
TABLE 26-9:
I/O PORTS
DC CHARACTERISTICS
Param.
No.
Sym.
VIL
Characteristic
Standard Operating Conditions (unless otherwise stated)
Min.
Typ.†
Max.
Units
Conditions
Input Low Voltage
I/O ports:
D036
with TTL buffer
D036A
D036B
with Schmitt Trigger buffer
D037
2
VSS
—
0.8
V
4.5V VDD 5.5V
VSS
—
0.15 VDD
V
1.8V VDD 4.5V
VSS
—
0.2 VDD
V
2.0V VDD 5.5V
VSS
—
0.2 VDD
V
1.8V VDD 5.5V
D037A
with I C levels
VSS
—
0.3 VDD
V
D037B
with SMBus levels
VSS
—
0.8 VDD
V
2.7V VDD 5.5V
D038
MCLR
VSS
—
0.2 VDD
V
D039
OSC1
VSS
—
0.3 VDD
V
HS, HSPLL modes
D039A
OSC1
VSS
—
0.2 VDD
V
EC, RC modes(1)
D039B
OSC1
VSS
—
0.3 VDD
V
XT, LP modes
T1CKI
VSS
—
0.3 VDD
V
2.0
—
VDD
V
4.5V VDD 5.5V
0.25 VDD +
0.8
—
VDD
V
1.8V VDD 4.5V
1.8V VDD 5.5V
D039C
VIH
Input High Voltage
I/O ports:
D040
with TTL buffer
D040A
D041
with Schmitt Trigger buffer
0.8 VDD
—
VDD
V
D041A
with I2C levels
0.7 VDD
—
VDD
V
D037A
with SMBus levels
D042
MCLR
2.1
—
VDD
V
0.8 VDD
—
VDD
V
2.7V VDD 5.5V
D042A
MCLR
0.9 VDD
—
0.3 VDD
V
1.8V VDD 2.4V
D043
OSC1
0.7 VDD
—
VDD
V
HS, HSPLL modes
D043A
OSC1
0.8 VDD
—
VDD
V
EC mode
D043B
OSC1
0.9 VDD
—
VDD
V
RC mode(1)
D043C
OSC1
1.6
—
VDD
V
XT, LP modes
D043E
T1CKI
1.6
—
VDD
V
—
±5
± 100
nA
—
±5
± 1000
nA
VSS VPIN VDD, Pin at
high-impedance, -40°C to 85°C
VSS VPIN VDD, 85°C to 125°C
—
± 50
± 200
nA
VSS VPIN VDD
50
250
400
A
VDD = 5.0V, VPIN = VSS
IIL
Input Leakage Current(2)
D060
I/O ports
D061
MCLR(3)
IPUR
PORTB Weak Pull-up Current
D070*
*
†
Note 1:
2:
3:
4:
These parameters are characterized but not tested.
Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
In RC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended to use an external
clock in RC mode.
Negative current is defined as current sourced by the pin.
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.
Including OSC2 in CLKOUT mode.
DS40001365F-page 334
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-9:
I/O PORTS (CONTINUED)
DC CHARACTERISTICS
Param.
No.
Sym.
VOL
D080
Characteristic
Standard Operating Conditions (unless otherwise stated)
Min.
Typ.†
Max.
Units
—
—
VSS+0.6
VSS+0.6
VSS+0.6
V
Output Low Voltage(4)
I/O ports
*
†
Note 1:
2:
3:
4:
Conditions
IOL = 8 mA, VDD = 5V
IOL = 6 mA, VDD = 3.3V
IOL = 3 mA, VDD = VDDMIN
These parameters are characterized but not tested.
Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
In RC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended to use an external
clock in RC mode.
Negative current is defined as current sourced by the pin.
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.
Including OSC2 in CLKOUT mode.
2009-2016 Microchip Technology Inc.
DS40001365F-page 335
PIC18(L)F1XK22
TABLE 26-9:
I/O PORTS (CONTINUED)
DC CHARACTERISTICS
Param.
No.
Sym.
VOH
D090
Characteristic
Standard Operating Conditions (unless otherwise stated)
Min.
Typ.†
Max.
Units
VDD-0.7
VDD-0.7
VDD-0.7
—
—
V
—
—
15
pF
—
—
50
pF
Conditions
Output High Voltage(4)
I/O ports
IOH = 3.5 mA, VDD = 5V
IOH = 3 mA, VDD = 3.3V
IOH = 2 mA, VDD = VDDMIN
Capacitive Loading Specs on Output Pins
D101*
COSC2 OSC2 pin
D101A* CIO
*
†
Note 1:
2:
3:
4:
All I/O pins
In XT, HS and LP modes when
external clock is used to drive
OSC1
These parameters are characterized but not tested.
Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
In RC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended to use an external
clock in RC mode.
Negative current is defined as current sourced by the pin.
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.
Including OSC2 in CLKOUT mode.
DS40001365F-page 336
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-10: MEMORY PROGRAMMING REQUIREMENTS
DC CHARACTERISTICS
Param.
No.
Sym.
Standard Operating Conditions (unless otherwise stated)
Characteristic
Min.
Typ.†
Max.
Units
Conditions
Internal Program Memory
Programming Specifications(1)
D110
VPP
Voltage on MCLR/VPP/RA3 pin
8
—
9
V
D113
IDDP
Supply Current during Programming
—
—
10
mA
100K
—
—
E/W
(Note 3, Note 4)
Data EEPROM Memory(2)
D120
ED
Byte Endurance
D121
VDRW
VDD for Read/Write
VDDMIN
—
VDDMAX
V
D122
TDEW
Erase/Write Cycle Time
—
3
4
ms
D123
TRETD
Characteristic Retention
—
40
—
Year
Provided no other
specifications are violated
D124
TREF
Number of Total Erase/Write Cycles
before Refresh(2)
1M
10M
—
E/W
-40°C to +85°C
10k
—
—
E/W
Temperature during programming: 10°C TA 40°C
D130
-40C to +85C
Using EECON to read/write
Program Flash Memory
EP
D131
VPR
D131A
Cell Endurance
VDDMIN
—
VDDMAX
V
Voltage on MCLR/VPP during
Erase/Program
VDD for Read
8.0
—
9.0
V
Temperature during programming: 10°C TA 40°C
2.7
—
VDDMAX
V
Temperature during programming: 10°C TA 40°C
2.2
VDDMIN
—
—
VDDMAX
VDDMAX
V
PIC18LF1XK22
PIC18F1XK22
D131B
VBE
VDD for Bulk Erase
D132
VPEW
VDD for Write or Row Erase
D132A
IPPPGM Current on MCLR/VPP during
Erase/Write
—
1.0
—
mA
Temperature during programming: 10°C TA 40°C
D132B
IDDPGM Current on VDD during Erase/Write
—
5.0
—
mA
Temperature during programming: 10°C TA 40°C
D133
TPEW
Erase/Write cycle time
—
2.0
2.8
ms
Temperature during programming: 10°C TA 40°C
D134
TRETD
Characteristic Retention
—
40
—
Year
†
Note 1:
2:
3:
4:
Provided no other
specifications are violated
Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
These specifications are for programming the on-chip program memory through the use of table write instructions.
Refer to Section 5.8 “Using the Data EEPROM” for a more detailed discussion on data EEPROM endurance.
Required only if single-supply programming is disabled.
The MPLAB ICD 2 does not support variable VPP output. Circuitry to limit the ICD 2 VPP voltage must be placed
between the ICD 2 and target system when programming or debugging with the ICD 2.
2009-2016 Microchip Technology Inc.
DS40001365F-page 337
PIC18(L)F1XK22
TABLE 26-11: THERMAL CHARACTERISTICS
Standard Operating Conditions (unless otherwise stated)
Param.
No.
TH01
TH02
Sym.
JA
JC
Characteristic
Typ.
Units
Thermal Resistance Junction to Ambient
62.2
C/W
20-pin PDIP package
75.0
C/W
20-pin SOIC package
89.3
C/W
20-pin SSOP package
43.0
C/W
20-pin QFN 4x4mm package
27.5
C/W
20-pin PDIP package
23.1
C/W
20-pin SOIC package
31.1
C/W
20-pin SSOP package
5.3
C/W
20-pin QFN 4x4mm package
150
C
—
W
PD = PINTERNAL + PI/O
—
W
PINTERNAL = IDD x VDD(1)
Thermal Resistance Junction to Case
TJMAX
Maximum Junction Temperature
TH04
PD
Power Dissipation
TH05
PINTERNAL Internal Power Dissipation
TH03
Conditions
TH06
PI/O
I/O Power Dissipation
—
W
PI/O = (IOL * VOL) + (IOH * (VDD - VOH))
TH07
PDER
Derated Power
—
W
PDER = PDMAX (TJ - TA)/JA(2)
Note 1:
2:
3:
IDD is current to run the chip alone without driving any load on the output pins.
TA = Ambient Temperature.
TJ = Junction Temperature.
DS40001365F-page 338
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
26.4
Timing Parameter Symbology
The timing parameter symbols have been created with
one of the following formats:
1. TppS2ppS
2. TppS
T
F
Frequency
Lowercase letters (pp) and their meanings:
pp
cc
CCP1
ck
CLKOUT
cs
CS
di
SDI
do
SDO
dt
Data in
io
I/O PORT
mc
MCLR
Uppercase letters and their meanings:
S
F
Fall
H
High
I
Invalid (High-impedance)
L
Low
FIGURE 26-7:
T
Time
osc
rd
rw
sc
ss
t0
t1
wr
OSC1
RD
RD or WR
SCK
SS
T0CKI
T1CKI
WR
P
R
V
Z
Period
Rise
Valid
High-impedance
LOAD CONDITIONS
Load Condition
Pin
CL
VSS
Legend: CL = 50 pF for all pins, 15 pF for
OSC2 output
2009-2016 Microchip Technology Inc.
DS40001365F-page 339
PIC18(L)F1XK22
26.5
AC Characteristics: PIC18(L)F1XK22-I/E
FIGURE 26-8:
CLOCK TIMING
Q4
Q1
Q2
Q3
Q4
Q1
OSC1/CLKIN
OS02
OS04
OS04
OS03
OSC2/CLKOUT
(LP,XT,HS Modes)
OSC2/CLKOUT
(CLKOUT Mode)
DS40001365F-page 340
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-12: EXTERNAL CLOCK TIMING REQUIREMENTS
Param.
No.
1A
Symbol
FOSC
Characteristic
External CLKIN
Frequency(1)
Oscillator Frequency(1)
1
TOSC
External CLKIN Period(1)
Oscillator Period(1)
Time(1)
2
TCY
Instruction Cycle
3
TOSL,
TOSH
External Clock in (OSC1)
High or Low Time
4
Note 1:
TOSR,
TOSF
External Clock in (OSC1)
Rise or Fall Time
Min.
Max.
Units
Conditions
DC
48
MHz
EC, ECIO Oscillator mode,
(Extended Range Devices)
DC
64
MHz
EC, ECIO Oscillator mode,
(Industrial Range Devices)
DC
4
MHz
RC Oscillator mode
0.1
4
MHz
XT Oscillator mode
4
25
MHz
HS Oscillator mode
4
16
MHz
HS + PLL Oscillator mode,
(Industrial Range Devices)
4
12
MHz
HS + PLL Oscillator mode,
(Extended Range Devices)
LP Oscillator mode
5
33
kHz
20.8
—
ns
EC, ECIO, Oscillator mode
(Extended Range Devices)
15.6
—
ns
EC, ECIO, Oscillator mode,
(Industrial Range Devices)
250
—
ns
RC Oscillator mode
250
10,000
ns
XT Oscillator mode
40
62.5
250
250
ns
ns
83.3
250
ns
HS Oscillator mode
HS + PLL Oscillator mode,
(Industrial range devices)
HS + PLL Oscillator mode,
(Extended Range Devices)
30
200
s
LP Oscillator mode
62.5
—
ns
TCY = 4/FOSC
30
—
ns
XT Oscillator mode
2.5
—
s
LP Oscillator mode
10
—
ns
HS Oscillator mode
—
20
ns
XT Oscillator mode
—
50
ns
LP Oscillator mode
—
7.5
ns
HS Oscillator mode
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/CLKIN pin. When an external clock
input is used, the “max.” cycle time limit is “DC” (no clock) for all devices.
2009-2016 Microchip Technology Inc.
DS40001365F-page 341
PIC18(L)F1XK22
TABLE 26-13: OSCILLATOR PARAMETERS
Standard Operating Conditions (unless otherwise stated)
Param.
No.
OS08
Sym.
HFOSC
OS09
OS10*
LFOSC
Characteristic
Internal Calibrated HFINTOSC
Frequency(2)
Internal LFINTOSC Frequency
TIOSC ST HFINTOSC
Wake-up from Sleep Start-up Time
Freq.
Tolerance
Min.
Typ.†
Max.
Units
2%
3%
—
—
16.0
16.0
—
—
MHz
MHz
5%
—
16.0
—
MHz
0
—
31.25
—
kHz
—
—
5
8
s
VDD = 2.0V, -40°C to +85°C
—
—
5
8
s
VDD = 3.0V, -40°C to +85°C
—
—
5
8
s
VDD = 5.0V, -40°C to +85°C
Conditions
0°C TA 60°C
60°C TA +85°C
*
†
These parameters are characterized but not tested.
Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period. All specified values are based on
characterization data for that particular oscillator type under standard operating conditions with the device executing
code. Exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current
consumption. All devices are tested to operate at “min” values with an external clock applied to the OSC1 pin. When an
external clock input is used, the “max” cycle time limit is “DC” (no clock) for all devices.
2: To ensure these oscillator frequency tolerances, VDD and VSS must be capacitively decoupled as close to the device as
possible. 0.1 F and 0.01 F values in parallel are recommended.
3: By design.
TABLE 26-14: PLL CLOCK TIMING SPECIFICATIONS (VDD = 1.8V TO 5.5V)
Param.
Sym.
No.
F10
F11
F12
F13*
Characteristic
FOSC Oscillator Frequency Range
FSYS
On-Chip VCO System Frequency
trc
PLL Start-up Time (Lock Time)
CLK
CLKOUT Stability (Jitter)
Min.
Typ.†
Max.
Units
Conditions
4
—
5
MHz VDD = 1.8-3.0V
4
—
16
MHz VDD = 3.0-5.0V,
-40°C to +85°C
4
—
12
MHz VDD = 3.0-5.0V,
125°C
16
—
20
MHz VDD = 1.8-3.0V
16
—
64
MHz VDD = 3.0-5.0V,
-40°C to +85°C
16
—
48
MHz VDD = 3.0-5.0V,
125°C
—
—
2
ms
-0.25
—
+0.25
%
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3V, 25C unless otherwise stated. These parameters are for design guidance
only and are not tested.
DS40001365F-page 342
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 26-9:
Cycle
CLKOUT AND I/O TIMING
Write
Fetch
Read
Execute
Q4
Q1
Q2
Q3
FOSC
OS12
OS11
OS20
OS21
CLKOUT
OS19
OS18
OS16
OS13
OS17
I/O pin
(Input)
OS14
OS15
I/O pin
(Output)
New Value
Old Value
OS18, OS19
TABLE 26-15: CLKOUT AND I/O TIMING PARAMETERS
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Sym.
Characteristic
Min.
Typ.† Max.
Units
Conditions
OS11
TOSH2CKL Fosc to CLKOUT (1)
—
—
70
ns
VDD = 3.3-5.0V
OS12
(1)
—
—
72
ns
VDD = 3.3-5.0V
—
—
20
ns
OS13
TOSH2CKH Fosc to CLKOUT
TCKL2IOV
CLKOUT to Port out
valid(1)
CLKOUT(1)
OS14
TIOV2CKH Port input valid before
TOSC + 200 ns
—
—
ns
OS15
TOSH2IOV Fosc (Q1 cycle) to Port out valid
—
50
70*
ns
VDD = 3.3-5.0V
OS16
TOSH2IOI
50
—
—
ns
VDD = 3.3-5.0V
OS17
TIOV2OSH Port input valid to Fosc(Q2 cycle)
(I/O in setup time)
20
—
—
ns
OS18
TIOR
Port output rise time(2)
—
—
40
15
72
32
ns
VDD = 1.8V
VDD = 3.3-5.0V
OS19
TIOF
Port output fall time(2)
—
—
28
15
55
30
ns
VDD = 1.8V
VDD = 3.3-5.0V
Fosc (Q2 cycle) to Port input invalid
(I/O in hold time)
OS20*
TINP
INT pin input high or low time
25
—
—
ns
OS21*
TRBP
PORTB interrupt-on-change new input
level time
25
—
—
ns
*
†
Note 1:
2:
These parameters are characterized but not tested.
Data in “Typ” column is at 3.0V, 25C unless otherwise stated.
Measurements are taken in RC mode where CLKOUT output is 4 x TOSC.
Includes OSC2 in CLKOUT mode.
2009-2016 Microchip Technology Inc.
DS40001365F-page 343
PIC18(L)F1XK22
FIGURE 26-10:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP
TIMER TIMING
VDD
MCLR
30
Internal
POR
33
PWRT
Time-out
32
OSC
Start-Up Time
Internal Reset(1)
Watchdog Timer
Reset(1)
31/
31A
34
34
I/O pins
Note 1: Asserted low.
FIGURE 26-11:
BROWN-OUT RESET TIMING AND CHARACTERISTICS
VDD
VBOR and VHYST
VBOR
(Device in Brown-out Reset)
(Device not in Brown-out Reset)
TBORREJ
37
Reset
(due to BOR)
33(1)
Note 1: 64 ms delay only if PWRTE bit in the Configuration Word register is programmed to ‘0’. 2 ms delay if PWRTE = 0.
DS40001365F-page 344
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-16: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER,
AND BROWN-OUT RESET PARAMETERS
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Sym.
Characteristic
Min.
Typ.† Max. Units
Conditions
30
TMCL
MCLR Pulse Width (low)
2
5
—
—
—
—
s
s
VDD = 3.3-5V, -40°C to +85°C
VDD = 3.3-5V
31
TWDT
Standard Watchdog Timer Time-out
Period (1:16 Prescaler)
10
10
17
17
27
30
ms
ms
VDD = 3.3V-5V, -40°C to +85°C
VDD = 3.3V-5V
31A
TWDTLP Low-Power Watchdog Timer
Time-out Period (No Prescaler)
10
10
18
18
27
33
ms
ms
VDD = 3.3V-5V, -40°C to +85°C
VDD = 3.3V-5V
32
TOST
Oscillator Start-up Timer Period(1,2)
—
1024
—
33*
TPWRT
Power-up Timer Period,
PWRTE = 0
40
65
140
ms
34*
TIOZ
I/O high-impedance from MCLR
Low or Watchdog Timer Reset
—
—
2.73
s
35
VBOR
Brown-out Reset Voltage
1.75
2.05
2.35
2.65
1.9
2.2
2.5
2.85
2.05
2.35
2.65
3.05
V
V
V
V
BORV = 1.9V(5)
BORV = 2.2V(5)
BORV = 2.7V
BORV = 2.85V
36*
VHYST
Brown-out Reset Hysteresis
0
25
50
mV
-40°C to +85°C
37*
TBORDC Brown-out Reset DC Response
Time
0
3
35
s
VDD VBOR
*
†
Note 1:
2:
3:
4:
5:
TOSC (Note 3)
These parameters are characterized but not tested.
Data in “Typ” column is at 3V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Instruction cycle period (TCY) equals four times the input oscillator time base period. All specified values are
based on characterization data for that particular oscillator type under standard operating conditions with
the device executing code. Exceeding these specified limits may result in an unstable oscillator operation
and/or higher than expected current consumption. All devices are tested to operate at “min” values with an
external clock applied to the OSC1 pin. When an external clock input is used, the “max” cycle time limit is
“DC” (no clock) for all devices.
By design.
Period of the slower clock.
To ensure these voltage tolerances, VDD and VSS must be capacitively decoupled as close to the device as
possible. 0.1 F and 0.01 F values in parallel are recommended.
PIC18LF1XK22 devices only.
2009-2016 Microchip Technology Inc.
DS40001365F-page 345
PIC18(L)F1XK22
FIGURE 26-12:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
40
41
42
T1CKI
45
46
49
47
TMR0 or
TMR1
TABLE 26-17: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Standard Operating Conditions (unless otherwise stated)
Param.
No.
40*
Sym.
TT0H
Characteristic
Min.
Typ.†
Max.
Units
0.5 TCY + 20
—
—
ns
10
—
—
ns
0.5 TCY + 20
—
—
ns
10
—
—
ns
Greater of:
20 or TCY + 40
N
—
—
ns
0.5 TCY + 20
—
—
ns
15
—
—
ns
30
—
—
ns
Synchronous, No Prescaler
0.5 TCY + 20
—
—
ns
Synchronous, with Prescaler
15
—
—
ns
Asynchronous
30
—
—
ns
Synchronous
Greater of:
30 or TCY + 40
N
—
—
ns
Asynchronous
60
—
—
ns
T0CKI High-Pulse Width
No Prescaler
With Prescaler
TT0L
41*
T0CKI Low-Pulse Width
No Prescaler
With Prescaler
42*
TT0P
T0CKI Period
45*
TT1H
T1CKI
Synchronous, No Prescaler
High Time Synchronous, with Prescaler
Asynchronous
TT1L
46*
TT1P
47*
T1CKI
Low Time
T1CKI
Input
Period
48
FT1
Timer1 Oscillator Input Frequency Range
(oscillator enabled by setting bit T1OSCEN)
32.4
32.76
8
33.1
kHz
49*
TCKEZTMR1
Delay from External Clock Edge to Timer
Increment
2 TOSC
—
7 TOSC
—
*
†
Conditions
N = prescale value
(2, 4, ..., 256)
N = prescale value
(1, 2, 4, 8)
Timers in Sync
mode
These parameters are characterized but not tested.
Data in “Typ” column is at 3V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
DS40001365F-page 346
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 26-13:
CAPTURE/COMPARE/PWM TIMINGS (CCP)
CCPx
(Capture mode)
CC01
CC02
CC03
Note:
Refer to Figure 26-7 for load conditions.
TABLE 26-18: CAPTURE/COMPARE/PWM REQUIREMENTS (CCP)
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Sym.
CC01*
TccL
Characteristic
CCPx Input Low Time
No Prescaler
Min.
Typ.†
Max.
Units
0.5TCY + 20
—
—
ns
20
—
—
ns
0.5TCY + 20
—
—
ns
20
—
—
ns
3TCY + 40
N
—
—
ns
With Prescaler
CC02*
TccH
CCPx Input High Time
No Prescaler
With Prescaler
CC03*
*
†
TccP
CCPx Input Period
Conditions
N = prescale value (1, 4 or 16)
These parameters are characterized but not tested.
Data in “Typ” column is at 3V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
TABLE 26-19: PIC18(L)F1XK22 A/D CONVERTER (ADC) CHARACTERISTICS
Standard Operating Conditions (unless otherwise stated)
Operating temperature: Tested at 25°C
Param.
Sym.
No.
Characteristic
Min.
Typ.†
Max.
Units
Conditions
AD01
NR
Resolution
—
—
10
bit
AD02
EIL
Integral Error
—
—
±2
LSb
VREF = 3.0V
AD03
EDL
Differential Error
—
—
±1.5
LSb
No missing codes
VREF = 3.0V
AD04
EOFF Offset Error
—
—
±3
LSb
VREF = 3.0V
AD05
EGN
VREF = 3.0V
AD06
VREF Change in Reference Voltage =
VREF+ - VREF-(2), (3)
AD07
VAIN
Full-Scale Range
AD08
ZAIN
Recommended Impedance of
Analog Voltage Source
Gain Error
—
—
±3
LSb
1.8
—
VDD
V
VSS
—
VREF
V
—
—
10
k
1.8 VREF+ VDD + 0.3V
VSS - 0.3V VREF- VREF+ - 1.8V
Can go higher if external 0.01 F capacitor is
present on input pin.
*
†
These parameters are characterized but not tested.
Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
Note 1: Total Absolute Error includes integral, differential, offset and gain errors.
2: ADC VREF is from external VREF, VDD pin or FVR, whichever is selected as reference input.
3: FVR voltage selected must be 2.048V or 4.096V.
2009-2016 Microchip Technology Inc.
DS40001365F-page 347
PIC18(L)F1XK22
FIGURE 26-14:
A/D CONVERSION TIMING
BSF ADCON0, GO
(Note 2)
131
Q4
130
132
A/D CLK
9
A/D DATA
8
7
.. .
...
2
1
0
NEW_DATA
OLD_DATA
ADRES
TCY
ADIF
GO
DONE
SAMPLING STOPPED
SAMPLE
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.
TABLE 26-20: A/D CONVERSION REQUIREMENTS
Param.
Symbol
No.
130*
TAD
Characteristic
A/D Clock Period
Min.
Max.
Units
Conditions
0.7
25.0(1)
s
TOSC based, VREF 3.0V,
0.7
4.0(1)
s
TOSC based, VREF 3.0V,
1.0
4.0
s
A/D RC mode
12
TAD
-40°C to +85°C
-40°C to +125°C
131
TCNV
Conversion Time
(not including acquisition time)(2)
12
132*
TACQ
Acquisition Time(3)
1.4
5.0
s
135
TSWC
Switching Time from Convert - Sample
—
—(4)
—
136
TDIS
Discharge Time
2
2
s
VDD 3.0V, RS = 50
* These parameters are characterized but not tested.
Note 1:
2:
3:
4:
The time of the A/D clock period is dependent on the device frequency and the TAD clock divider.
ADRES register may be read on the following TCY cycle.
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 50.
On the following cycle of the device clock.
DS40001365F-page 348
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-21: COMPARATOR SPECIFICATIONS
Standard Operating Conditions (unless otherwise stated)
Param.
No.
CM01
Sym.
Characteristics
VICM
Input Common-mode Voltage
CM04
TRESP
Response Time
*
Note 1:
Typ.
Max.
Units
—
10
50
mV
VREF = VDD/2,
High-Power mode
—
12
80
mV
VREF = VDD/2,
Low-Power mode
VSS
—
VDD
V
—
200
400
ns
High-Power mode
—
300
600
ns
Low-Power mode
—
—
10
s
Input Offset Voltage
VIOFF
CM02
CM05
Min.
TMC2OV
Comparator Mode Change to
Output Valid*
Comments
These parameters are characterized but not tested.
Response time measured with one comparator input at VDD/2, while the other input transitions from VSS
to VDD.
TABLE 26-22: DIGITAL-TO-ANALOG CONVERTER (DAC) SPECIFICATIONS
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Sym.
Characteristics
Min.
Typ.
Max.
Units
DAC01*
CLSB
Step Size
—
VDD/32
—
V
DAC02*
CACC
Absolute Accuracy
—
—
1/2
LSb
DAC03*
CR
Unit Resistor Value (R)
—
5k
—
DAC04*
CST
Settling Time(1)
—
—
10
s
*
Note 1:
Comments
These parameters are characterized but not tested.
Settling time measured while DACR transitions from ‘0000’ to ‘1111’.
TABLE 26-23: FIXED VOLTAGE REFERENCE (FVR) SPECIFICATIONS
VR Voltage Reference Specifications
Param.
No.
Sym.
Standard Operating Conditions (unless otherwise stated)
Characteristics
Min.
Typ.
Max.
Units
Comments
D003
VADFVR
Fixed Voltage Reference Voltage for
ADC, Initial Accuracy
-8
—
6
%
1.024V, VDD 2.5V(1)
2.048V, VDD 2.5V
4.096V, VDD 4.75V
D003A
VCDAFVR
Fixed Voltage Reference Voltage for
Comparator and DAC, Initial Accuracy
-11
—
7
%
1.024V, VDD 2.5V
2.048V, VDD 2.5V
4.096V, VDD 4.75V
D004*
SVDD
VDD Rise Rate to ensure internal
Power-on Reset signal
0.05
—
—
V/ms
*
Note 1:
See Section 22.3 “Power-on
Reset (POR)” for details.
These parameters are characterized but not tested.
For proper operation, the minimum value of the ADC positive voltage reference must be 1.8V or greater.
When selecting the FVR or the VREF+ pin as the source of the ADC positive voltage reference, be aware
that the voltage must be 1.8V or greater.
2009-2016 Microchip Technology Inc.
DS40001365F-page 349
PIC18(L)F1XK22
FIGURE 26-15:
USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING
CK
US121
US121
DT
US122
US120
Note:
Refer to Figure 26-7 for load conditions.
TABLE 26-24: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Symbol
Characteristic
Min.
Max.
Units
US120 TCKH2DTV SYNC XMIT (Master and Slave)
Clock high to data-out valid
3.0-5.5V
—
80
ns
1.8-5.5V
—
100
ns
Clock out rise time and fall time
(Master mode)
3.0-5.5V
—
45
ns
1.8-5.5V
—
50
ns
Data-out rise time and fall time
3.0-5.5V
—
45
ns
1.8-5.5V
—
50
ns
US121 TCKRF
US122 TDTRF
FIGURE 26-16:
Conditions
USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING
CK
US125
DT
US126
Note: Refer to Figure 26-7 for load conditions.
TABLE 26-25: USART SYNCHRONOUS RECEIVE REQUIREMENTS
Standard Operating Conditions (unless otherwise stated)
Param.
No.
Symbol
Characteristic
US125 TDTV2CKL SYNC RCV (Master and Slave)
Data-hold before CK (DT hold time)
US126 TCKL2DTL
Data-hold after CK (DT hold time)
DS40001365F-page 350
Min.
Max.
Units
10
—
ns
15
—
ns
Conditions
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 26-17:
SPI MASTER MODE TIMING (CKE = 0, SMP = 0)
SS
SP70
SCK
(CKP = 0)
SP71
SP72
SP78
SP79
SP79
SP78
SCK
(CKP = 1)
SP80
bit 6 - - - - - -1
MSb
SDO
LSb
SP75, SP76
SDI
MSb In
bit 6 - - - -1
LSb In
SP74
SP73
Note: Refer to Figure 26-7 for load conditions.
FIGURE 26-18:
SPI MASTER MODE TIMING (CKE = 1, SMP = 1)
SS
SP81
SCK
(CKP = 0)
SP71
SP72
SP79
SP73
SCK
(CKP = 1)
SP80
SDO
MSb
bit 6 - - - - - -1
SP78
LSb
SP75, SP76
SDI
MSb In
bit 6 - - - -1
LSb In
SP74
Note: Refer to Figure 26-7 for load conditions.
2009-2016 Microchip Technology Inc.
DS40001365F-page 351
PIC18(L)F1XK22
FIGURE 26-19:
SPI SLAVE MODE TIMING (CKE = 0)
SS
SP70
SCK
(CKP = 0)
SP83
SP71
SP72
SP78
SP79
SP79
SP78
SCK
(CKP = 1)
SP80
MSb
SDO
LSb
bit 6 - - - - - -1
SP77
SP75, SP76
SDI
MSb In
bit 6 - - - -1
LSb In
SP74
SP73
Note: Refer to Figure 26-7 for load conditions.
FIGURE 26-20:
SS
SPI SLAVE MODE TIMING (CKE = 1)
SP82
SP70
SP83
SCK
(CKP = 0)
SP71
SP72
SCK
(CKP = 1)
SP80
SDO
MSb
bit 6 - - - - - -1
LSb
SP77
SP75, SP76
SDI
MSb In
bit 6 - - - -1
LSb In
SP74
Note: Refer to Figure 26-7 for load conditions.
DS40001365F-page 352
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-26: SPI MODE REQUIREMENTS
Param.
No.
Symbol
Characteristic
SP70* TSSL2SCH,
TSSL2SCL
SS to SCK or SCK input
SP71* TSCH
Min.
Typ.† Max. Units Conditions
TCY
—
—
ns
SCK input high time (Slave mode)
TCY + 20
—
—
ns
SP72* TSCL
SCK input low time (Slave mode)
TCY + 20
—
—
ns
SP73* TDIV2SCH,
TDIV2SCL
Setup time of SDI data input to SCK edge
100
—
—
ns
SP74* TSCH2DIL,
TSCL2DIL
Hold time of SDI data input to SCK edge
100
—
—
ns
SP75* TDOR
SDO data output rise time
3.0-5.5V
—
10
25
ns
1.8-5.5V
—
25
50
ns
SDO data output fall time
—
10
25
ns
SP77* TSSH2DOZ
SS to SDO output high-impedance
10
—
50
ns
SP78* TSCR
SCK output rise time
(Master mode)
3.0-5.5V
—
10
25
ns
1.8-5.5V
—
25
50
ns
SP76*
TDOF
SP79* TSCF
SCK output fall time (Master mode)
—
10
25
ns
SP80* TSCH2DOV,
TSCL2DOV
SDO data output valid after
SCK edge
—
—
50
ns
3.0-5.5V
—
—
145
ns
SP81* TDOV2SCH, SDO data output setup to SCK edge
TDOV2SCL
1.8-5.5V
Tcy
—
—
ns
SP82* TSSL2DOV
SDO data output valid after SS edge
—
—
50
ns
SP83* TSCH2SSH,
TSCL2SSH
SS after SCK edge
1.5TCY + 40
—
—
ns
* These parameters are characterized but not tested.
† Data in “Typ” column is at 3.0V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
FIGURE 26-21:
I2C BUS START/STOP BITS TIMING
SCL
SP93
SP91
SP90
SP92
SDA
Start
Condition
Stop
Condition
Note: Refer to Figure 26-7 for load conditions.
2009-2016 Microchip Technology Inc.
DS40001365F-page 353
PIC18(L)F1XK22
TABLE 26-27: I2C BUS START/STOP BITS REQUIREMENTS
Param.
No.
Symbol
SP90*
TSU:STA
SP91*
THD:STA
SP92*
TSU:STO
SP93
THD:STO Stop condition
Characteristic
Start condition
100 kHz mode
4700
Typ. Max. Units
—
—
Setup time
400 kHz mode
600
—
—
Start condition
100 kHz mode
4000
—
—
Hold time
400 kHz mode
600
—
—
Stop condition
100 kHz mode
4700
—
—
Setup time
Hold time
*
Min.
400 kHz mode
600
—
—
100 kHz mode
4000
—
—
400 kHz mode
600
—
—
Conditions
ns
Only relevant for Repeated
Start condition
ns
After this period, the first
clock pulse is generated
ns
ns
These parameters are characterized but not tested.
FIGURE 26-22:
I2C BUS DATA TIMING
SP103
SCL
SP100
SP90
SP102
SP101
SP106
SP107
SP91
SDA
In
SP92
SP110
SP109
SP109
SDA
Out
Note: Refer to Figure 26-7 for load conditions.
DS40001365F-page 354
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
TABLE 26-28: I2C BUS DATA REQUIREMENTS
Param.
No.
Symbol
SP100*
THIGH
Characteristic
Clock high time
Min.
Max.
Units
Conditions
100 kHz mode
4.0
—
s
Device must operate at a
minimum of 1.5 MHz
400 kHz mode
0.6
—
s
Device must operate at a
minimum of 10 MHz
1.5TCY
—
100 kHz mode
4.7
—
s
Device must operate at a
minimum of 1.5 MHz
400 kHz mode
1.3
—
s
Device must operate at a
minimum of 10 MHz
1.5TCY
—
SSP Module
SP101*
TLOW
Clock low time
SSP Module
SP102*
SP103*
TR
TF
SDA and SCL rise
time
100 kHz mode
—
1000
ns
400 kHz mode
20 +
0.1CB
300
ns
SDA and SCL fall
time
100 kHz mode
—
250
ns
400 kHz mode
20 +
0.1CB
250
ns
CB is specified to be from
10-400 pF
100 kHz mode
4.7
—
s
Only relevant for
Repeated Start condition
SP90*
TSU:STA
Start condition
setup time
400 kHz mode
0.6
—
s
SP91*
THD:STA
Start condition hold 100 kHz mode
time
400 kHz mode
4.0
—
s
0.6
—
s
SP106*
THD:DAT
Data input hold
time
100 kHz mode
0
—
ns
400 kHz mode
0
0.9
s
SP107*
TSU:DAT
Data input setup
time
100 kHz mode
250
—
ns
400 kHz mode
100
—
ns
SP92*
TSU:STO
Stop condition
setup time
100 kHz mode
4.7
—
s
400 kHz mode
0.6
—
s
SP109*
TAA
Output valid from
clock
100 kHz mode
—
3500
ns
400 kHz mode
—
—
ns
SP110*
TBUF
Bus free time
100 kHz mode
4.7
—
s
400 kHz mode
1.3
—
s
—
400
pF
SP
CB
*
Note 1:
2:
Bus capacitive loading
CB is specified to be from
10-400 pF
After this period the first
clock pulse is generated
(Note 2)
(Note 1)
Time the bus must be free
before a new transmission can start
These parameters are characterized but not tested.
As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region
(min. 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions.
A Fast mode (400 kHz) I2C bus device can be used in a Standard mode (100 kHz) I2C bus system, but the
requirement TSU:DAT 250 ns must then be met. This will automatically be the case if the device does not
stretch the low period of the SCL signal. If such a device does stretch the low period of the SCL signal, it
must output the next data bit to the SDA line TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the
Standard mode I2C bus specification), before the SCL line is released.
2009-2016 Microchip Technology Inc.
DS40001365F-page 355
PIC18(L)F1XK22
27.0
DC AND AC CHARACTERISTICS GRAPHS AND CHARTS
The graphs and tables provided in this section are for design guidance and are not tested.
In some graphs or tables, the data presented are outside specified operating range (i.e., outside specified VDD
range). This is for information only and devices are ensured to operate properly only within the specified range.
Note:
The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore, outside the warranted range.
“Typical” represents the mean of the distribution at 25C. “MAXIMUM”, “Max.”, “MINIMUM” or “Min.”
represents (mean + 3) or (mean - 3) respectively, where is a standard deviation, over each
temperature range.
DS40001365F-page 356
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 27-1:
PIC18LF1XK22 TYPICAL BASE IPD
5
4.5
4
125°C
3.5
IPD (uA)
3
2.5
2
1.5
1
85°C
25°C
-40°C
0.5
0
1.8
2
2.2
2.4
2.6
2.8
3
VDD (V)
FIGURE 27-2:
PIC18LF1XK22 TYPICAL IPD FOR WATCHDOG TIMER
6.0
5.4
125°C
4.8
IPD (uA)
4.2
3.6
3.0
2.4
1.8
85°C
1.2
Typ. 25°C
0.6
0.0
1.8
2
2.2
2.4
2.6
2.8
3
VDD (V)
2009-2016 Microchip Technology Inc.
DS40001365F-page 357
PIC18(L)F1XK22
FIGURE 27-3:
PIC18LF1XK22 TYPICAL IPD FOR BROWN-OUT RESET
16
14
125°C
12
10
IPD (uA)
85°C
8
Typ. 25°C
6
4
2
0
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3
VDD (V)
FIGURE 27-4:
PIC18LF1XK22 TYPICAL IPD FOR DIGITAL-TO-ANALOG CONVERTER (CVREF)
40
35
30
25
IPD (uA)
125°C
85°C
20
25°C
15
10
5
0
1.8
2
2.2
2.4
2.6
2.8
3
VDD (V)
DS40001365F-page 358
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 27-5:
PIC18LF1XK22 ICOMP – TYPICAL IPD FOR COMPARATOR IN LOW-POWER
MODE
25.0
IPD (uA)
20.0
15.0
125°C
85°C
10.0
25°C
-40°C
5.0
1.8
2
2.2
2.4
2.6
2.8
3
VDD (V)
FIGURE 27-6:
PIC18LF1XK22 ICOMP – TYPICAL IPD FOR COMPARATOR IN HIGH-POWER
MODE
125
100
75
IPD (uA)
125°C
85°C
25°C
50
-40°C
25
0
1.8
2
2.2
2.4
2.6
2.8
3
VDD (V)
2009-2016 Microchip Technology Inc.
DS40001365F-page 359
PIC18(L)F1XK22
FIGURE 27-7:
PIC18LF1XK22 TYPICAL RC_RUN 31 kHz IDD
30
25
IDD (uA)
20
15
125°C
85°C
10
25°C
-40°C
5
0
1.8
2
2.2
2.4
2.6
2.8
3
2.6
2.8
3
VDD (V)
FIGURE 27-8:
PIC18LF1XK22 TYPICAL RC_RUN IDD
5.0
4.5
4.0
IDD (mA)
3.5
3.0
16 MHz
2.5
2.0
1.5
1.0
1 MHz
0.5
0.0
1.8
2
2.2
2.4
VDD (V)
DS40001365F-page 360
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 27-9:
PIC18LF1XK22 TYPICAL PRI_RUN IDD (EC)
4.0
3.5
3.0
16 MHz
IDD (mA)
2.5
2.0
1.5
1.0
0.5
1 MHz
0.0
1.8
2
2.2
2.4
2.6
2.8
3
VDD (V)
FIGURE 27-10:
PIC18LF1XK22 TYPICAL PRI_RUN IDD (HS + PLL)
5.0
4.5
4.0
3.5
IDD (mA)
3.0
16 MHz
(4 MHz Input)
2.5
2.0
1.5
1.0
0.5
0.0
1.8
2
2.2
2.4
2.6
2.8
3
VDD (V)
2009-2016 Microchip Technology Inc.
DS40001365F-page 361
PIC18(L)F1XK22
FIGURE 27-11:
MEMLOW TYPICAL BASE IPD
50
45
40
35
125°C
IPD (uA)
30
25
85°C
20
25°C
15
-40°C
10
5
0
2.3
2.8
3.3
3.8
4.3
4.8
VDD (V)
FIGURE 27-12:
MEMLOW TYPICAL IPD FOR WATCHDOG TIMER
40.0
35.0
125°C
30.0
85°C
IPD (uA)
25.0
Typ. 25°C
20.0
15.0
15 0
10.0
5.0
0.0
2.3
2.8
3.3
3.8
4.3
4.8
VDD (V)
DS40001365F-page 362
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 27-13:
MEMLOW TYPICAL IPD FOR BROWN-OUT RESET
80
70
60
125°C
85°C
IPD (uA)
50
Typ. 25°C
40
30
20
10
0
3
3.2
3.4
3.6
3.8
4
4.2
4.4
4.6
4.8
5
VDD (V)
FIGURE 27-14:
MEMLOW TYPICAL IPD FOR DIGITAL-TO-ANALOG CONVERTER (CVREF)
80
70
60
125°C
85°C
IPD (uA)
50
25°C
40
30
20
10
0
2.3
2.8
3.3
3.8
4.3
4.8
VDD (V)
2009-2016 Microchip Technology Inc.
DS40001365F-page 363
PIC18(L)F1XK22
FIGURE 27-15:
MEMLOW ICOMP – TYPICAL IPD FOR COMPARATOR IN LOW-POWER MODE
60.0
55.0
50.0
45.0
125°C
IPD (uA)
40.0
85°C
35.0
25°C
30.0
-40°C
25.0
20.0
15.0
10.0
2.3
2.8
3.3
3.8
4.3
4.8
VDD (V)
FIGURE 27-16:
MEMLOW ICOMP – TYPICAL IPD FOR COMPARATOR IN HIGH-POWER MODE
150
125
125°C
100
85°C
IPD (uA)
25°C
75
-40°C
50
25
0
2.3
2.8
3.3
3.8
4.3
4.8
VDD (V)
DS40001365F-page 364
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 27-17:
MEMLOW TYPICAL RC_RUN 31 kHz IDD
50
45
40
125°C
IDD (uA)
35
85°C
25°C
30
-40°C
25
20
15
10
5
0
2.3
2.8
3.3
3.8
4.3
4.8
VDD (V)
FIGURE 27-18:
MEMLOW TYPICAL RC_RUN IDD
5.0
4.5
4.0
16 MHz
3.5
IDD (mA)
3.0
2.5
2.0
1.5
1.0
1 MHz
0.5
0.0
2.3
2.8
3.3
3.8
4.3
4.8
VDD (V)
2009-2016 Microchip Technology Inc.
DS40001365F-page 365
PIC18(L)F1XK22
FIGURE 27-19:
MEMLOW TYPICAL PRI_RUN IDD (EC)
14
64 MHz
12
10
IDD (mA)
8
6
4
16 MHz
2
1 MHz
0
2.3
2.8
3.3
3.8
4.3
4.8
VDD (V)
FIGURE 27-20:
MEMLOW TYPICAL PRI_RUN IDD (HS + PLL)
16
14
64 MHz
(16 MHz Input)
12
IDD (mA)
10
8
6
4
16 MHz
(4 MHz Input)
2
0
2.3
2.8
3.3
3.8
4.3
4.8
VDD (V)
DS40001365F-page 366
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 27-21:
PIC18(L)F1XK22 TTL BUFFER TYPICAL VIH
2.1
1.9
Min.
1.7
1.5
-40°C
VIH (V)
1.3
25°C
1.1
85°C
125°C
0.9
0.7
0.5
0.3
0.1
1.8
2.3
2.8
3.3
3.8
4.3
4.8
5.3
VDD (V)
FIGURE 27-22:
PIC18(L)F1XK22 SCHMITT TRIGGER BUFFER TYPICAL VIH
4.5
4.0
3.5
VIH (V)
Min.
3.0
2.5
2.0
-40°C
1.5
125°C
1.0
1.8
2.3
2.8
3.3
3.8
4.3
4.8
5.3
VDD (V)
2009-2016 Microchip Technology Inc.
DS40001365F-page 367
PIC18(L)F1XK22
FIGURE 27-23:
PIC18(L)F1XK22 TTL BUFFER TYPICAL VIL
2.1
1.9
1.7
1.5
VIL (V)
1.3
25°C
1.1
-40°C
0.9
125°C
85°C
0.7
Max.
0.5
0.3
0.1
1.8
2.3
2.8
3.3
3.8
4.3
4.8
5.3
VDD (V)
FIGURE 27-24:
PIC18(L)F1XK22 SCHMITT BUFFER TYPICAL VIL
2.0
1.8
1.6
-40°C
VIL (V)
1.4
1.2
1.0
125°C
Max.
0.8
0.6
0.4
0.2
1.8
2.3
2.8
3.3
3.8
4.3
4.8
5.3
VDD (V)
DS40001365F-page 368
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 27-25:
MEMLOW TYPICAL LF-INTOSC FREQUENCY (MAX./MIN. = 31.25 kHz ± 15%)
33.3
Frequency (kHz)
F
32.3
25°C
-40°C
31.3
85°C
30.3
125°C
29.3
28.3
2
2.5
3
3.5
4
4.5
5
5.5
VDD (V)
FIGURE 27-26:
MEMLOW TYPICAL LF-INTOSC FREQUENCY (MAX./MIN. = 31.25 kHz ± 15%)
Frequency
F
(kHz)
32.5
32.0
2.5V
31.5
3.0V
5.5V
31.0
30.5
30.0
29.5
29.0
-40
-20
0
20
40
60
80
100
120
Temperature (°C)
2009-2016 Microchip Technology Inc.
DS40001365F-page 369
PIC18(L)F1XK22
FIGURE 27-27:
PIC18LF1XK22 TYPICAL LF-INTOSC FREQUENCY (MAX./MIN. = 31.25 kHz ±
15%)
33.3
32.3
31.3
Frequency (kHz)
30.3
25°C
29.3
-40°C
85°C
28.3
125°C
27.3
26.3
25.3
2
2.4
2.8
3.2
3.6
VDD (V)
FIGURE 27-28:
PIC18LF1XK22 TYPICAL LF-INTOSC FREQUENCY (MAX./MIN. = 31.25 kHz ±
15%)
33.0
32 0
32.0
Frequency (kH
F
Hz)
31.0
2.5V
3V
3.6V
30.0
29.0
28.0
27.0
26.0
-40
-20
0
20
40
60
80
100
120
Temperature (°C)
DS40001365F-page 370
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
FIGURE 27-29:
MEMLOW TYPICAL VOH vs. IOH
6
5
VOH (V)
4
3
5.5V
2
4.0V
3.0V
1
2.0V
0
0
5
10
15
20
25
30
35
IOH (mA)
FIGURE 27-30:
MEMLOW TYPICAL VOL vs. IOL
2.5
2.0
1.5
VOL (V)
1.8V
3.0
1.0
4.0V
5.5V
0.5
0.0
0
5
10
15
20
25
30
IOL (mA)
2009-2016 Microchip Technology Inc.
DS40001365F-page 371
PIC18(L)F1XK22
28.0
PACKAGING INFORMATION
28.1
Package Marking Information
20-Lead PDIP (300 mil)
XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXX
YYWWNNN
20-Lead SSOP (5.30 mm)
Example
PIC18F13K22
-E/P e3
0910017
Example
PIC18F13K22
-I/SS e3
0910017
Legend: XX...X
Y
YY
WW
NNN
e3
*
Note:
DS40001365F-page 372
Customer-specific information
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
Pb-free JEDEC® designator for Matte Tin (Sn)
This package is Pb-free. The Pb-free JEDEC designator ( e3 )
can be found on the outer packaging for this package.
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.
2009-2016 Microchip Technology Inc.
PIC18(L)F1XK22
Package Marking Information (Continued)
Example
20-Lead SOIC (7.50 mm)
PIC18F14K22
-E/SO e3
0910017
20-Lead QFN (4x4x0.9 mm)
PIN 1
Example
PIN 1
Legend: XX...X
Y
YY
WW
NNN
e3
*
Note:
PIC18
F14K22
E/ML e3
910017
Customer-specific information
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
Pb-free JEDEC® designator for Matte Tin (Sn)
This package is Pb-free. The Pb-free JEDEC designator ( e3 )
can be found on the outer packaging for this package.
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.
2009-2016 Microchip Technology Inc.
DS40001365F-page 373
PIC18(L)F1XK22
28.2
Package Details
The following sections give the technical details of the packages.
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