MICROCHIP PIC16C781

PIC16C781.book Page 1 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
8-Bit CMOS Microcontrollers with A/D, D/A, OPAMP,
Comparators and PSMC
Microcontroller Core Features:
Microcontroller Core Features (Continued):
• High performance RISC CPU
• Only 35 single word instructions to learn
• All single cycle instructions except for program
branches which are two cycle
• Direct, indirect and relative addressing modes
- Operating speed: DC - 20 MHz clock input
DC - 200 ns instruction cycle
• Low power, high speed CMOS EPROM
technology
• Fully static design
• Low power consumption:
- < 2 mA @ 5V, 4 MHz
- < 1 A typical standby current.
Data Memory
X8
PIC16C781
1K
128
PIC16C782
2K
128
Pin Diagram
PDIP, Windowed CERDIP, SOIC, SSOP
• 8-level deep hardware stack
• Interrupt capability (up to 8 internal/external
interrupt sources)
• 16 I/O pins:
- Individual direction control (13 pins)
- Input only (3 pins), low leakage (2 pins)
- Digital/Analog inputs (8 pins)
• Programmable PORTB interrupt-on-change (8 pins)
• Programmable PORTB weak pull-ups (8 pins)
• Power-on Reset (POR)
• Power-up Timer (PWRT) and
Oscillator Start-up Timer (OST)
• Watchdog Timer (WDT) with a software enabled
option and its own on-chip RC oscillator for
reliable operation
• Programmable Brown-out Reset (BOR)
• Programmable Low Voltage Detection (LVD)
• Internal/external MCLR
• Programmable code protection
• Power saving SLEEP mode
• Selectable oscillator options:
HS, XT, LP, EC, RC, INTRC (4 MHz/37 kHz)
• In-Circuit Serial Programming™ (ISCP™)
• Program Memory Read (PMR) capability
• Four user programmable ID locations
• Wide operating voltage range:
- 2.5V to 5.5V for commercial and industrial
temperature ranges
- Extended temperature range available
 2001-2013 Microchip Technology Inc.
RA0/AN0/OPA+
RA1/AN1/OPARA4/T0CKI
RA5/MCLR/VPP
VSS
AVSS
RA2/AN2/VREF2
RA3/AN3/VREF1
RB0/INT/AN4/VR
RB1/AN5/VDAC
•1
1
22
33
44
55
66
77
88
99
10
PIC16C781/782
Device
Program
Memory
X14
20
19
18
17
16
15
14
13
12
11
RB3/AN7/OPA
RB2/AN6
RA7/OSC1/CLKIN
RA6/OSC2/CLKOUT/T1CKI
VDD
AVDD
RB7/C2/PSMC1B/T1G
RB6/C1/PSMC1A
RB5
RB4
Peripheral Features:
• Timer0: 8-bit timer/counter with 8-bit prescaler
• Enhanced Timer1:
- 16-bit timer/counter with prescaler
- External Gate Input mode
- Option to use OSC1 and OSC2 in LP mode
as Timer1 oscillator, if INTRC oscillator mode
selected
• Analog-to-Digital Converter (ADC):
- 8-bit resolution
- Programmable 8-channel input
- Internal voltages available for selfdiagnostics
• Digital-to-Analog Converter (DAC):
- 8-bit resolution
- Reference from AVDD, VREF1, or VR module
- Output configurable to VDAC pin, Comparators, and ADC reference
• Operational Amplifier module (OPA):
- Firmware initiated input offset voltage Auto
Calibration module
- Low leakage inputs
- Programmable Gain Bandwidth Product
(GBWP)
Preliminary
DS41171B-page 1
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PIC16C781/782
Peripheral Features (Continued):
• Programmable Switch Mode Controller module:
- PWM and PSM modes
- Programmable switching frequency
- Configurable for either single or dual
feedback inputs
- Configurable single or dual outputs
- Slope compensation output available in
single output mode
• Dual Analog Comparator module with:
- Individual enable and interrupt bits
- Programmable speed and output polarity
- Fully configurable inputs and outputs
- Reference from DAC, or VREF1/VREF2
- Low input offset voltage.
• VR voltage reference module:
- 3.072V +/- 0.7% @25C, AVDD = 5V
- Configurable output to ADC reference, DAC
reference, and VR pin
- 5 mA sink/source
Key Features
PIC® Mid-Range
Reference Manual
(DS33023)
Operating Frequency
RESETS (and Delays)
PIC16C781
PIC16C782
DC - 20 MHz
DC - 20 MHZ
POR, BOR, MCLR, WDT (PWRT, OST) POR, BOR, MCLR, WDT (PWRT, OST)
Program Memory (14 bit words)
1K
2K
Data Memory (bytes)
128
128
Interrupts
8
8
I/O Ports
13 + 3 Input only
13 + 3 Input only
Timers
2
2
Programmable Switch Mode Controller
1
1
8-bit Analog-to-Digital Module
1
1
8 External, 2 Internal
8 External, 2 Internal
8-bit Digital-to-Analog Module
1
1
Comparators
2
2
4 (AN<7:4>)
4 (AN<7:4>)
ADC channels
Comparator Channels
Operational Amplifier
1
1
Voltage Reference
1
1
Brown-out Reset
Yes
Yes
Programmable Low Voltage Detect
Yes
Yes
Instruction Set
35 Instructions
35 Instructions
DS41171B-page 2
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PIC16C781/782
Table of Contents
1.0 Device Overview ......................................................................................................................................................................... 5
2.0 Memory Organization ................................................................................................................................................................ 11
3.0 I/O Ports .................................................................................................................................................................................... 25
4.0 Program Memory Read (PMR) .................................................................................................................................................. 47
5.0 Timer0 Module .......................................................................................................................................................................... 51
6.0 Timer1 Module with Gate Control .............................................................................................................................................. 55
7.0 Voltage Reference Module (VR) ................................................................................................................................................ 61
8.0 Programmable Low Voltage Detect Module (PLVD) ................................................................................................................. 63
9.0 Analog-to-Digital Converter (ADC) Module ............................................................................................................................... 69
10.0 Digital-to-Analog Converter (DAC) Module ............................................................................................................................... 79
11.0 Operational Amplifier (OPA) Module ......................................................................................................................................... 83
12.0 Comparator Module ................................................................................................................................................................... 89
13.0 Programmable Switch Mode Controller (PSMC) ....................................................................................................................... 99
14.0 Special Features of The CPU .................................................................................................................................................. 117
15.0 Instruction Set Summary ......................................................................................................................................................... 133
16.0 Development Support .............................................................................................................................................................. 141
17.0 Electrical Characteristics ......................................................................................................................................................... 147
18.0 DC and AC Characteristics Graphs and Tables ...................................................................................................................... 167
19.0 Packaging Information ............................................................................................................................................................. 169
Index .................................................................................................................................................................................................. 175
On-Line Support................................................................................................................................................................................. 181
Reader Response .............................................................................................................................................................................. 182
PIC16C781/782 Product Identification System .................................................................................................................................. 183
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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To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:
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You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page.
The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current
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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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 2001-2013 Microchip Technology Inc.
Preliminary
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PIC16C781/782
NOTES:
DS41171B-page 4
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 5 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
1.0
DEVICE OVERVIEW
manual is highly recommended reading for a better
understanding of the device architecture and operation
of the peripheral modules.
This document contains device-specific information.
Additional information may be found in the PIC MidRange Reference Manual (DS33023), which may be
obtained from your local Microchip Sales Representative or downloaded from the Microchip website. The
Reference manual should be considered a complementary document to this data sheet. The Reference
FIGURE 1-1:
This data sheet covers two devices: PIC16C781 and
PIC16C782. Both devices come in a variety of 20-pin
packages.
The following figures are block diagrams of the
PIC16C781 and the PIC16C782.
PIC16C781 BLOCK DIAGRAM
13
8
Data Bus
Program Counter
EPROM
PORTA
RA0/AN0/OPA+
RA1/AN1/OPARA2/AN2/VREF2
RA3/AN3/VREF1
RA4/T0CKI
RA5/MCLR/VPP
RA6/OSC2/CLKOUT/T1CKI
RA7/OSC1/CLKIN
Program
Memory
RAM
8 Level Stack
(13-bit)
1K x 14
File
Registers
128 x 8
RAM
9
Addr
Program Memory
Read (PMR)
Program 14
Bus
Addr MUX
Instruction reg
PORTB
7
Direct Addr
8
Indirect
Addr
FSR reg
STATUS reg
8
3
Power-up
Timer
OSC1/
CLKIN
Instruction
Decode &
Control
Timing
Generation
Oscillator
Start-up Timer
Power-on
Reset
Watchdog
Timer
Internal
RC
Oscillator
INTRC
Timer0
(TMR0)
ALU
Comparator
(C1)
Programmable Switch
Mode Controller
(PSMC)
AVDD, AVSS(1)
8
VDD, VSS
W reg
Brown-out
Reset
OSC2/
CLKOUT
MUX
RB0/INT/AN4/VR
RB1/AN5/VDAC
RB2/AN6
RB3/AN7/OPA
RB4
RB5
RB6/C1/PSMC1A
RB7/C2/PSMC1B/T1G
Timer1
(TMR1)
Voltage Reference
(VR) Module
Comparator
(C2)
8-bit ADC
OPAMP
(OPA)
8-bit
DAC
Programmable
Low Voltage Detect
(PLVD)
Note 1: AVDD and AVSS pins are used by the following modules: C1, C2, OPA, DAC, ADC, and VR.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 5
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PIC16C781/782
FIGURE 1-2:
PIC16C782 BLOCK DIAGRAM
13
Program
Memory
RA0/AN0/OPA+
RA1/AN1/OPARA2/AN2/VREF2
RA3/AN3/VREF1
RA4/T0CKI
RA5/MCLR/VPP
RA6/OSC2/CLKOUT/T1CKI
RA7/OSC1/CLKIN
File
Registers
128 x 8
RAM
9
Addr
Program Memory
Read (PMR)
Program 14
Bus
Addr MUX
Instruction reg
7
Direct Addr
8
Indirect
Addr
FSR reg
STATUS reg
8
3
Power-up
Timer
OSC1/
CLKIN
Instruction
Decode &
Control
Timing
Generation
OSC2/
CLKOUT
Internal
RC
Oscillator
INTRC
Oscillator
Start-up Timer
Power-on
Reset
Watchdog
Timer
Brown-out
Reset
MUX
ALU
Comparator
C1
Programmable Switch
Mode Controller
PSMC
PORTB
RB0/INT/AN4/VR
RB1/AN5/VDAC
RB2/AN6
RB3/AN7/OPA
RB4
RB5
RB6/C1/PSMC1A
RB7/C2/PSMC1B/T1G
AVSS, AVSS(1)
8
VDD, VSS
W reg
Timer1
(TMR1)
Voltage Reference
Module
(VR)
Timer0
TMR0
PORTA
RAM
8 Level Stack
(13-bit)
2K x 14
8
Data Bus
Program Counter
EPROM
Comparator
C2
8-bit ADC
OPAMP
OPA
8-bit
DAC
Programmable
Low Voltage Detect
PLVD
Note 1: AVDD and AVSS pins are used for the following modules: C1, C2, OPA, DAC, ADC, and VR.
DS41171B-page 6
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
ANALOG SIGNAL MULTIPLEXING DIAGRAM
OPAON
CMPEN
GBWP
OPA
RA0/AN0/OPA+
0
RA1/AN1/OPA-
1
RA2/AN2/VREF2
2
RA3/AN3/VREF1
3
RB0/INT/AN4/VR
4
RB1/AN5/VDAC
5
RB2/AN6
6
VCFG<1:0>
CHS<2:0>
AVDD
3
VREF1
0
1
VR
2
VDAC
3
ADCREF
ADC
ADON
GO/DONE
7 EN
RB3/AN7/OPA
VROE & VREN
CHS3
VR
AN4
VR
REFERENCE
0 EN
VDAC
8
ADRES
FIGURE 1-3:
1
VREN
2
AN4
CHS0
C1CH<1:0>
0
AN5
C1SP
2
AN7
C1POL
C1OUT
3
C1R
VREF1
1
2
AN4
0
AN5
1
AN6
2
AN7
3
2
3
C2OUT
C2R
C2
DAON & DAOE
AN4
DAC REGISTER
N/C
1
C2POL
1
DARS<1:0>
VR
RB7/C2
PSMC1B
C2ON
0
VDAC
0
C2OE
C2CH<1:0>
C2SP
VREF2
VREF1
C1
0
VDAC
2
RB6/C1/
PSMC1A
C1ON
1
AN6
AVDD
C1OE
DACREF
DAC
8
VDAC
DAON
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 7
PIC16C781.book Page 8 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
TABLE 1-1:
PIC16C781/782 PINOUT DESCRIPTION
Name
RA0/AN0/OPA+
RA1/AN1/OPA-
RA2/AN2/VREF2
RA3/AN3/VREF1
RA4/T0CKI
RA5/MCLR/VPP
RA6/OSC2/CLKOUT/T1CKI
RA7/OSC1/CLKIN
RB0/INT/AN4/VR
RB1/AN5/VDAC
RB2/AN6
RB3/AN7/OPA
Input
Type
Output
Type
RA0
ST
N/A
Port Input
AN0
AN
—
ADC Input
OPA+
AN
—
OPAMP Non-inverting Input
RA1
ST
N/A
Port Input
AN1
AN
—
ADC Input
OPA-
AN
—
RA2
ST
CMOS
Function
AN2
AN
—
VREF2
AN
—
RA3
ST
CMOS
AN3
AN
—
VREF1
AN
—
RA4
ST
OD
TOCKI
ST
—
RA5
ST
N/A
MCLR
ST
—
Description
OPAMP Inverting Input
Bi-directional I/O
ADC Input
Comparator 2 Voltage Reference Input
Bi-directional I/O
ADC Input
Comparator 1, ADC, DACREF Input
Bi-directional I/O
Timer0 Clock Input
Port Input
Master Clear Input
VPP
Power
—
RA6
ST
CMOS
Bi-directional I/O
Programming Voltage
OSC2
—
XTAL
Crystal/Resonator
CLKOUT
—
CMOS
Fosc/4 Output
T1CKI
ST
—
RA7
ST
CMOS
Timer1 Clock Input
Bi-directional I/O
OSC1
XTAL
—
Crystal/Resonator
CLKIN
ST
—
External Clock Input
RB0
TTL
CMOS
Bi-directional I/O
INT
ST
—
External Interrupt
AN4
AN
—
VR
—
AN
RB1
TTL
CMOS
AN5
AN
—
VDAC
—
AN
RB2
TTL
CMOS
AN6
AN
—
RB3
TTL
CMOS
AN7
AN
—
ADC, Comparator Input
Internal Voltage Reference Output
Bi-directional I/O
ADC, Comparator Input
DAC Output
Bi-directional I/O
ADC, Comparator Input
Bi-directional I/O
ADC, Comparator Input
OPA
—
AN
OPAMP Output
RB4
RB4
TTL
CMOS
Bi-directional I/O
RB5
RB5
TTL
CMOS
Bi-directional I/O
RB6
TTL
CMOS
Bi-directional I/O
C1
—
CMOS
Comparator 1 Output
PSMC1A
—
CMOS
PSMC Output 1A
RB6/C1/PSMC1A
DS41171B-page 8
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
TABLE 1-1:
PIC16C781/782 PINOUT DESCRIPTION (CONTINUED)
Function
Input
Type
Output
Type
RB7
TTL
CMOS
Bi-directional I/O
C2
—
CMOS
Comparator 2 Output
PSMC1B
—
CMOS
PSMC Output 1B
T1G
ST
—
Timer 1 Gate Input
AVDD
AVDD
Power
—
Positive Supply for Analog
AVSS
AVSS
Power
—
Ground Reference for Analog
VDD
VDD
Power
—
Positive Supply for Logic and I/O pins
VSS
VSS
Power
—
Ground Reference for Logic and I/O pins
Legend: ST = Schmitt Trigger
XTAL = Crystal
AN = Analog
CMOS = CMOS Output
Name
RB7/C2/PSMC1B/T1G
 2001-2013 Microchip Technology Inc.
Description
OD = open drain
Power = Power Supply
Preliminary
TTL = Logic Level
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PIC16C781/782
NOTES:
DS41171B-page 10
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PIC16C781/782
2.0
MEMORY ORGANIZATION
FIGURE 2-2:
PIC16C782 PROGRAM
MEMORY MAP AND
STACK
There are two memory blocks in each of these PIC®
microcontrollers. Each block (program and data memory) has its own bus, so that concurrent access can
occur.
PC<12:0>
Additional information on device memory may be found
in the PIC Mid-Range Reference Manual, (DS33023).
2.1
CALL, RETURN
RETFIE, RETLW
Program Memory Organization
Stack Level 1
The PIC16C781/782 devices have a 13-bit program
counter capable of addressing an 8K x 14 program
memory space. The PIC16C781 has 1K x 14 words of
program memory. The PIC16C782 has 2K x 14 words
of program memory. Accessing a location above the
physically implemented address causes a wraparound.
Stack Level 2
Stack Level 8
The RESET vector is at 0000h and the interrupt vector
is at 0004h.
FIGURE 2-1:
PIC16C781 PROGRAM
MEMORY MAP AND
STACK
PC<12:0>
CALL, RETURN
RETFIE, RETLW
13
On-Chip
Program
Memory
RESET Vector
0000h
Interrupt Vector
0004h
0005h
Page 0
07FFh
0800h
13
Stack Level 1
Stack Level 2
1FFFh
Stack Level 8
RESET Vector
Interrupt Vector
On-Chip
Program
Memory
0000h
0004h
0005h
Page 0
03FFh
0400h
2.2
Data Memory Organization
The data memory is partitioned into multiple banks,
which contain the General Purpose Registers and the
Special Function Registers. Bits RP0 and RP1 are
bank select bits.
RP1 RP0
(STATUS<6:5>)
= 00  Bank0
= 01  Bank1
= 10  Bank2
= 11  Bank3
1FFFh
 2001-2013 Microchip Technology Inc.
Each bank extends up to 7Fh (128 bytes). The lower
locations of each bank are reserved for the Special
Function Registers. Above the Special Function Registers are the General Purpose Registers, implemented
as static RAM. All implemented banks contain Special
Function Registers. Some frequently used Special
Function Registers from one bank are mirrored in
another bank for code reduction and quicker access.
Preliminary
DS41171B-page 11
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PIC16C781/782
FIGURE 2-3:
REGISTER FILE MAP
File
Address
Indirect addr.(*)
TMR0
PCL
STATUS
FSR
PORTA
PORTB
PCLATH
INTCON
PIR1
TMR1L
TMR1H
T1CON
ADRES
ADCON0
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
0Ah
0Bh
0Ch
0Dh
0Eh
0Fh
10h
11h
12h
13h
14h
15h
16h
17h
18h
19h
1Ah
1Bh
1Ch
1Dh
1Eh
1Fh
20h
General
Purpose
Register
File
Address
Indirect addr.(*) 80h
OPTION_REG 81h
82h
PCL
83h
STATUS
84h
FSR
85h
TRISA
86h
TRISB
87h
88h
89h
8Ah
PCLATH
8Bh
INTCON
PIE1
8Ch
8Dh
8Eh
PCON
8Fh
90h
91h
92h
93h
94h
95h
WPUB
IOCB
96h
97h
98h
99h
9Ah
9Bh
REFCON
LVDCON
9Ch
ANSEL
9Dh
9Eh
9Fh
ADCON1
General
Purpose
Register
32 Bytes
96 Bytes
accesses
70h-7Fh
7Fh
Bank 0
File
Address
Indirect addr.(*)
TMR0
PCL
STATUS
FSR
PORTB
PCLATH
INTCON
PMDATL
PMADRL
PMDATH
PMADRH
CALCON
PSMCCON0
PSMCCON1
CM1CON0
CM2CON0
CM2CON1
OPACON
DAC
DACON0
A0h
File
Address
100h
101h
102h
103h
104h
105h
106h
107h
108h
109h
10Ah
10Bh
10Ch
10Dh
10Eh
10Fh
110h
111h
112h
113h
114h
115h
116h
117h
118h
119h
11Ah
11Bh
11Ch
11Dh
11Eh
11Fh
Indirect addr.(*) 180h
OPTION_REG 181h
182h
PCL
183h
STATUS
184h
FSR
185h
186h
TRISB
187h
188h
189h
18Ah
PCLATH
18Bh
INTCON
18Ch
PMCON1
18Dh
18Eh
18Fh
190h
191h
192h
193h
194h
195h
196h
197h
198h
199h
19Ah
19Bh
19Ch
19Dh
19Eh
19Fh
120h
1A0h
BFh
EFh
F0h
accesses
70h-7Fh
accesses
70h-7Fh
17Fh
FFh
Bank 2
Bank 1
170h
1F0h
1FFh
Bank 3
Unimplemented data memory locations, read as '0'.
* Not a physical register.
DS41171B-page 12
Preliminary
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PIC16C781/782
2.2.1
GENERAL PURPOSE REGISTER
FILE
2.2.2
The Special Function Registers are registers used by
the CPU and Peripheral Modules for controlling the
desired operation of the device. These registers are
implemented as static RAM. A list of these registers is
given in Table 2-1.
The register file can be accessed either directly, or indirectly, through the File Select Register (FSR).
TABLE 2-1:
Address
SPECIAL FUNCTION REGISTERS
PIC16C781/782 SPECIAL FUNCTION REGISTER SUMMARY
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Details on
Page:
23
Bank 0
00h(2)
INDF
Addressing this location uses contents of FSR to address data memory (not a physical register)
0000 0000
01h
TMR0
Timer0 Module’s Register
xxxx xxxx
51
02h(2)
PCL
Program Counter's (PC) Least Significant Byte
0000 0000
23
03h(2)
STATUS
0001 1xxx
17
04h(2)
FSR
xxxx xxxx
23
05h
PORTA
RA7
RA6
RA5
RA4
RA3
RA2
RA1
RA0
xxxx 0000
26
06h
PORTB
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0
xxxx 0000
35
07h
—
Unimplemented
—
—
08h
—
Unimplemented
—
—
09h
—
Unimplemented
—
—
---0 0000
23
0Ah(1, 2)
PCLATH
0Bh(2)
INTCON
0Ch
PIR1
0Dh
—
0Eh
IRP
RP1
RP0
TO
PD
Z
DC
C
Indirect Data Memory Address Pointer
—
—
—
Write Buffer for the upper 5 bits of the Program Counter
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x
19
LVDIF
ADIF
C2IF
C1IF
—
—
—
TMR1IF
0000 ---0
21
Unimplemented
TMR1L
Holding register for the Least Significant Byte of the 16-bit TMR1 Register
0Fh
TMR1H
Holding register for the Most Significant Byte of the 16-bit TMR1 Register
10h
T1CON
—
TMR1GE T1CKPS1
T1CKPS0
T1OSCEN
T1SYNC
TMR1CS
TMR1ON
—
—
xxxx xxxx
55
xxxx xxxx
55
-000 0000
57
11h
—
Unimplemented
—
—
12h
—
Unimplemented
—
—
13h
—
Unimplemented
—
—
14h
—
Unimplemented
—
—
15h
—
Unimplemented
—
—
16h
—
Unimplemented
—
—
17h
—
Unimplemented
—
—
18h
—
Unimplemented
—
—
19h
—
Unimplemented
—
—
1Ah
—
Unimplemented
—
—
1Bh
—
Unimplemented
—
—
1Ch
—
Unimplemented
—
—
1Dh
—
Unimplemented
—
—
1Eh
ADRES
xxxx xxxx
71
1Fh
ADCON0
0000 0000
70
ADC Result Register
ADCS1
ADCS0
CHS2
CHS1
CHS0
GO/DONE
CHS3
ADON
Legend:
Note
x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as '0'.
Shaded locations are unimplemented, read as ‘0’.
1: The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8> whose contents are transferred to the upper byte of the program counter. See Section 2.9 for more detail.
2: These registers can be addressed from any bank.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 13
PIC16C781.book Page 14 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
TABLE 2-1:
Address
PIC16C781/782 SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED)
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Details on
Page:
0000 0000
23
Bank 1
80h(2)
INDF
81h
OPTION_REG
82h(2)
PCL
Addressing this location uses contents of FSR to address data memory (not a physical register)
RBPU
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
Program Counter's (PC) Least Significant Byte
1111 1111
18
0000 0000
23
0001 1xxx
17
83h(2)
STATUS
84h(2)
FSR
Indirect Data Memory Address Pointer
xxxx xxxx
23
85h
TRISA
PORTA Data Direction Register
1111 1111
26
86h
TRISB
PORTB Data Direction Register
IRP
RP1
RP0
TO
PD
Z
DC
C
1111 1111
35
87h
—
Unimplemented
—
—
88h
—
Unimplemented
—
—
89h
—
Unimplemented
—
—
---0 0000
23
8Ah(1,2)
PCLATH
8Bh(2)
INTCON
8Ch
PIE1
8Dh
—
8Eh
PCON
—
—
—
Write Buffer for the upper 5 bits of the Program Counter
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x
19
LVDIE
ADIE
C2IE
C1IE
—
—
—
TMR1IE
0000 ---0
20
Unimplemented
—
—
—
WDTON
OSCF
—
POR
BOR


---q 1-qq
22, 120
8Fh

Unimplemented
—
—
90h
—
Unimplemented
—
—
91h
—
Unimplemented
—
—
92h
—
Unimplemented
—
—
93h
—
Unimplemented
—
—
94h
—
Unimplemented
—
—
95h
WPUB
PORTB Weak Pull-up Control
1111 1111
36
96h
IOCB
PORTB Interrupt-on-Change Control
1111 0000
36
97h
—
Unimplemented
—
—
98h
—
Unimplemented
—
—
99h
—
Unimplemented
—
—
9Ah
—
Unimplemented
—
—
---- 00--
61
9Bh
REFCON
9Ch
LVDCON
9Dh
ANSEL
9Eh
—
9Fh
ADCON1
—
—
—
—
VREN
VROE
—

—
—
BGST
LVDEN
LV3
LV2
LV1
LV0
Analog Channel Select
Unimplemented
—
—
VCFG1
VCFG0
—
—
—
—
--00 0101
66
1111 1111
25
—
—
--00 ----
71
Legend:
Note
x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as '0'.
Shaded locations are unimplemented, read as ‘0’.
The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8> whose contents are transferred to the upper byte of the program counter. See Section 2.9 for more detail.
2: These registers can be addressed from any bank.
1:
DS41171B-page 14
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 15 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
TABLE 2-1:
Address
PIC16C781/782 SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED)
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Details on
Page:
23
Bank 2
100h(2)
INDF
Addressing this location uses contents of FSR to address data memory (not a physical register)
0000 0000
101h
TMR0
Timer0 Module’s Register
xxxx xxxx
51
102h(2)
PCL
Program Counter's (PC) Least Significant Byte
0000 0000
23
103h(2)
STATUS
0001 1xxx
17
104h(2)
FSR
xxxx xxxx
23
IRP
RP1
RP0
TO
PD
Z
DC
C
Indirect Data Memory Address Pointer
105h
—
106h
PORTB
107h
—
108h
—
109h
—
10Ah(1,2) PCLATH
Unimplemented
—
—
xxxx 0000
35
Unimplemented
—
—
Unimplemented
—
—
Unimplemented
—
—
---0 0000
23
RB7
—
RB6
—
RB5
—
RB4
RB3
RB2
RB1
RB0
Write Buffer for the upper 5 bits of the Program Counter
10Bh(2)
INTCON
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x
19
10Ch
PMDATL
PMD7
PMD6
PMD5
PMD4
PMD3
PMD2
PMD1
PMD0
0000 0000
48
10Dh
PMADRL
PMA7
PMA6
PMA5
PMA4
PMA3
PMA2
PMA1
PMA0
xxxx xxxx
48
10Eh
PMDATH
—
—
PMD13
PMD12
PMD11
PMD10
PMD9
PMD8
--00 0000
47
10Fh
PMADRH
—
—
—
Reserved
Reserved
PMA10
PMA9
PMA8
---x xxxx
48
110h
CALCON
CAL
CALERR
CALREF
—
—
—
—
—
000- ----
85
111h
PSMCCON0
SMCCL1 SMCCL0
MINDC1
MINDC0
MAXDC1
MAXDC0
DC1
DC0
0000 0000
104
112h
PSMCCON1
SMCON
S1BPOL
—
SCEN
SMCOM
PWM/PSM
SMCCS
000- 0000
104
113h
—
Unimplemented
—
—
114h
—
Unimplemented
—
—
115h
—
Unimplemented
—
—
116h
—
Unimplemented
—
—
117h
—
Unimplemented
—
—
118h
—
Unimplemented
—
—
C1CH0
0000 0000
91
119h
CM1CON0
11Ah
CM2CON0
11Bh
CM2CON1
11Ch
OPACON
11Dh
—
11Eh
DAC
11Fh
DACON0
S1APOL
C1ON
C1OUT
C1OE
C1POL
C1SP
C1R
C1CH1
C2ON
C2OUT
C2OE
C2POL
C2SP
C2R
C2CH1
C2CH0
0000 0000
93
—
—
—
—
—
C2SYNC
00-- ---0
94
—
—
—
—
—
GBWP
00-- ---0
84
MC1OUT MC2OUT
OPAON
CMPEN
Unimplemented
—
—
DA7
DA6
DA5
DA4
DA3
DA2
DA1
DA0
0000 0000
79
DAON
DAOE
—
—
—
—
DARS1
DARS0
00-- --00
79
Legend:
Note
x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as '0'.
Shaded locations are unimplemented, read as ‘0’.
1: The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8> whose contents are transferred to the upper byte of the program counter. See Section 2.9 for more detail.
2: These registers can be addressed from any bank.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 15
PIC16C781.book Page 16 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
TABLE 2-1:
Address
PIC16C781/782 SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED)
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Details on
Page:
0000 0000
23
Bank 3
180h(2)
INDF
181h
OPTION_REG
182h(2)
PCL
183h(2)
STATUS
184h(2)
FSR
185h
Addressing this location uses contents of FSR to address data memory (not a physical register)
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
Program Counter's (PC) Least Significant Byte
IRP
RP1
RP0
TO
PD
Z
DC
C
Indirect Data Memory Address Pointer
—
186h
RBPU
TRISB
Unimplemented
PORTB Data Direction Register
1111 1111
18
0000 0000
23
0001 1xxx
17
xxxx xxxx
23
—
—
1111 1111
35
187h
—
Unimplemented
—
—
188h
—
Unimplemented
—
—
189h
—
Unimplemented
—
—
---0 0000
23
18Ah(1,2) PCLATH
—
—
—
Write Buffer for the upper 5 bits of the Program Counter
18Bh(2)
INTCON
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x
19
18Ch
PMCON1
Reserved
—
—
—
—
—
—
RD
1--- ---0
47
18Dh
—
Unimplemented
—
—
18Eh
—
Unimplemented
—
—
18Fh
—
Unimplemented
—
—
190h
—
Unimplemented
—
—
191h
—
Unimplemented
—
—
192h
—
Unimplemented
—
—
193h
—
Unimplemented
—
—
194h
—
Unimplemented
—
—
195h
—
Unimplemented
—
—
196h
—
Unimplemented
—
—
197h
—
Unimplemented
—
—
198h
—
Unimplemented
—
—
199h
—
Unimplemented
—
—
19Ah
—
Unimplemented
—
—
19Bh
—
Unimplemented
—
—
19Ch
—
Unimplemented
—
—
19Dh
—
Unimplemented
—
—
19Eh
—
Unimplemented
—
—
19Fh
—
Unimplemented
—
—
Legend:
Note
x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as '0'.
Shaded locations are unimplemented, read as ‘0’.
1: The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8> whose contents are transferred to the upper byte of the program counter. See Section 2.9 for more detail.
2: These registers can be addressed from any bank.
DS41171B-page 16
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 17 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
2.3
STATUS Register
The STATUS register, shown in Register 2-1, contains
the arithmetic status of the ALU, the RESET status and
the bank select bits for data memory.
The STATUS register can be the destination for any
instruction, as with any other register. If the STATUS
register is the destination for an instruction that affects
the Z, DC, or C bits, the write to these three bits is disabled. These bits are set or cleared according to the
device logic. The TO and PD bits are not writable.
Therefore, the result of an instruction with the STATUS
register as the destination may be different than
intended.
REGISTER 2-1:
For example, CLRF STATUS clears the upper three bits
and sets the Z bit. This leaves the STATUS register as
000u u1uu (where u = unchanged).
It is recommended, therefore, that only BCF, BSF,
SWAPF and MOVWF instructions are used to alter the
STATUS register, since these instructions do not affect
the Z, C, or DC bits from the STATUS register. For other
instructions not affecting any status bits, see the
"Instruction Set Summary."
Note:
The C and DC bits operate as a borrow
and digit borrow bit, respectively, in subtraction. See the SUBLW and SUBWF
instructions for examples.
STATUS REGISTER (STATUS: 03h, 83h, 103h, 183h)
R/W-0
R/W-0
R/W-0
R-1
R-1
R/W-x
R/W-x
R/W-x
IRP
RP1
RP0
TO
PD
Z
DC
C
bit7
bit0
bit 7
IRP: Register Bank Select bit (used for indirect addressing)
1 = Bank 2, 3 (100h - 1FFh)
0 = Bank 0, 1 (00h - FFh)
bit 6-5
RP<1:0>: Register Bank Select bits (used for direct addressing)
11 = Bank 3 (180h - 1FFh)
10 = Bank 2 (100h - 17Fh)
01 = Bank 1 (80h - FFh)
00 = Bank 0 (00h - 7Fh)
Each bank is 128 bytes
bit 4
TO: Time-out bit
1 = After power-up, CLRWDT instruction, or SLEEP instruction
0 = A WDT time-out occurred
bit 3
PD: Power-down bit
1 = After power-up or by the CLRWDT instruction
0 = By execution of the SLEEP instruction
bit 2
Z: Zero bit
1 = The result of an arithmetic or logic operation is zero
0 = The result of an arithmetic or logic operation is not zero
bit 1
DC: Digit carry/borrow bit (ADDWF, ADDLW,SUBLW,SUBWF instructions) (for borrow, the polarity
is reversed)
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 = 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:
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 or low order bit of the source register.
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
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 17
PIC16C781.book Page 18 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
2.4
OPTION_REG Register
Note:
The OPTION_REG register is a readable and writable
register which contains various control bits to configure:
To achieve a 1:1 prescaler assignment for
the TMR0 register, assign the prescaler to
the Watchdog Timer.
• TMR0 prescaler/WDT postscaler (single assignable register known also as the prescaler)
• External INT interrupt
• TMR0
• Weak pull-ups on PORTB
REGISTER 2-2:
OPTION REGISTER (OPTION_REG: 81h, 181h)
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
RBPU
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
bit7
bit0
bit 7
RBPU: PORTB Pull-up Enable bit(1)
1 = PORTB weak pull-ups are disabled
0 = PORTB weak pull-ups are enabled by the WPUB register
bit 6
INTEDG: Interrupt Edge Select bit
1 = Interrupt on rising edge of RB0/INT pin
0 = Interrupt on falling edge of RB0/INT pin
bit 5
T0CS: TMR0 Clock Source Select bit
1 = Transition on RA4/T0CKI pin
0 = Internal instruction cycle clock (FOSC/4)
bit 4
T0SE: TMR0 Source Edge Select bit
1 = Increment on high-to-low transition on RA4/T0CKI pin
0 = Increment on low-to-high transition on RA4/T0CKI pin
bit 3
PSA: Prescaler Assignment bit
1 = Prescaler is assigned to the WDT
0 = Prescaler is assigned to the Timer0 module
bit 2-0
PS<2:0>: Prescaler Rate Select bits
Bit Value
000
001
010
011
100
101
110
111
TMR0 Rate
1:2
1:4
1:8
1 : 16
1 : 32
1 : 64
1 : 128
1 : 256
WDT Rate
1:1
1:2
1:4
1:8
1 : 16
1 : 32
1 : 64
1 : 128
Note 1: Individual weak pull-ups on RB pins can be enabled/disabled from the weak pull-up
PORTB register (WPUB).
Legend:
DS41171B-page 18
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
’1’ = Bit is set
’0’ = Bit is cleared
Preliminary
x = Bit is unknown
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 19 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
2.5
INTCON Register
Note:
The INTCON register is a readable and writable register which contains:
• Enable and interrupt flag bits for TMR0 register
overflow
• Enable and interrupt flag bits for the external
interrupt (INT)
• Enable and interrupt flag bits for PORTB
Interrupt-on-Change (IOCB)
• Peripheral interrupt enable bit
• Global interrupt enable bit
REGISTER 2-3:
Interrupt flag bits are set when an interrupt
condition occurs, regardless of the state of
its corresponding enable bit, or the global
enable bit, GIE (INTCON<7>). User software should ensure the appropriate interrupt flag bits are clear prior to enabling an
interrupt.
INTERRUPT CONTROL REGISTER (INTCON: 0Bh, 8Bh, 10Bh, 18Bh)
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
PEIE
T01E
INTE
RBIE
T0IF
INTF
RBIF
bit 7
bit 0
bit 7
GIE: Global Interrupt Enable bit
1 = Enables all unmasked interrupts
0 = Disables all interrupts
bit 6
PEIE: Peripheral Interrupt Enable bit
1 = Enables all unmasked peripheral interrupts
0 = Disables all peripheral interrupts
bit 5
T0IE: TMR0 Overflow Interrupt Enable bit
1 = Enables the TMR0 interrupt
0 = Disables the TMR0 interrupt
bit 4
INTE: RB0/INT External Interrupt Enable bit
1 = Enables the RB0/INT external interrupt
0 = Disables the RB0/INT external interrupt
bit 3
RBIE: RB Port Change Interrupt Enable bit(1)
1 = Enables the RB port change interrupt
0 = Disables the RB port change interrupt
bit 2
T0IF: TMR0 Overflow Interrupt Flag bit
1 = TMR0 register has overflowed (must be cleared in software)
0 = TMR0 register did not overflow
bit 1
INTF: RB0/INT External Interrupt Flag bit
1 = The RB0/INT external interrupt occurred (must be cleared in software)
0 = The RB0/INT external interrupt did not occur
bit 0
RBIF: RB Port Change Interrupt Flag bit(1)
1 = When at least one of the RB7:RB0 pins changed state (must be cleared in software)
0 = None of the RB7:RB0 pins have changed state
Note 1: Individual RB pin interrupt-on-change can be enabled/disabled from the Interrupton-Change PORTB register (IOCB).
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
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 19
PIC16C781.book Page 20 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
2.6
PIE1 Register
Note:
The PIE1 register contains the individual enable bits for
the peripheral interrupts.
REGISTER 2-4:
Bit PEIE (INTCON<6>) must be set to
enable any peripheral interrupt (see
Register 2-3).
PERIPHERAL INTERRUPT ENABLE REGISTER (PIE1: 8Ch)
R/W-0
R/W-0
R/W-0
R/W-0
U-0
U-0
U-0
R/W-0
LVDIE
ADIE
C2IE
C1IE
—
—
—
TMR1IE
bit0
bit7
bit 7
LVDIE: Low Voltage Detect Interrupt Enable bit
1 = LVD interrupt is enabled
0 = LVD interrupt is disabled
bit 6
ADIE: Analog-to-Digital Converter Interrupt Enable bit
1 = Enables the Analog-to-Digital Converter interrupt
0 = Disables the Analog-to-Digital Converter interrupt
bit 5
C2IE: Comparator C2 Interrupt Enable bit
1 = Enables the Comparator C2 interrupt
0 = Disables the Comparator C2 interrupt
bit 4
C1IE: Comparator C1 Interrupt Enable bit
1 = Enables the Comparator C1 interrupt
0 = Disables the Comparator C1 interrupt
bit 3-1
Unimplemented: Read as '0'
bit 0
TMR1IE: TMR1 Overflow Interrupt Enable bit
1 = Enables the TMR1 overflow interrupt
0 = Disables the TMR1 overflow interrupt
Legend:
DS41171B-page 20
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
’1’ = Bit is set
’0’ = Bit is cleared
Preliminary
x = Bit is unknown
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 21 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
2.7
PIR1 Register
Note:
This register contains the individual flag bits for the
peripheral interrupts.
REGISTER 2-5:
Interrupt flag bits are set when an interrupt
condition occurs, regardless of the state of
its corresponding enable bit, or the global
enable bit, GIE (INTCON<7>). User software should ensure the appropriate interrupt flag bits are clear prior to enabling an
interrupt.
PERIPHERAL INTERRUPT REGISTER (PIR1 0Ch)
R/W-0
R/W-0
R/W-0
R/W-0
U-0
U-0
U-0
R/W-0
LVDIF
ADIF
C2IF
C1IF
—
—
—
TMR1IF
bit7
bit 0
bit 7
LVDIF: Low Voltage Detect Interrupt Flag bit
1 = The supply voltage has fallen below the specified LVD voltage (must be cleared in software)
0 = The supply voltage is greater than the specified LVD voltage
bit 6
ADIF: Analog-to-Digital Converter Interrupt Flag bit
1 = An ADC conversion completed (must be cleared in software)
0 = The ADC conversion is not complete
bit 5
C2IF: Comparator C2 Interrupt Flag bit
1 = Comparator C2 input has crossed the threshold (must be cleared in software)
0 = Comparator C2 input has not crossed the threshold
bit 4
C1IF: Comparator C1 Interrupt Flag bit
1 = Comparator C1 input has crossed the threshold (must be cleared in software)
0 = Comparator C1 input has not crossed the threshold
bit 3-1
Unimplemented: Read as ‘0’
bit 0
TMR1IF: TMR1 Overflow Interrupt Flag bit
1 = TMR1 register overflowed (must be cleared in software)
0 = TMR1 register did not overflow
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
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 21
PIC16C781.book Page 22 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
2.8
PCON Register
The Power Control (PCON) register contains two flag
bits to allow determination of the source of the most
recent RESET:
• Power-on Reset (POR)
• External MCLR Reset
• Power Supply Brown-out (BOR) Reset
Typical Time Inactive
Direction of Change
Minimum
100 s
300 s
37 kHz4 MHz
1.25 s
3.25 s
Note:
The Power Control register also contains frequency
select bits for the INTRC oscillator and the WDT software enable bit.
Note:
Maximum
4 MHz  37 kHz
When changing the internal oscillator
speed (i.e., the OSCF bit, INTRC mode),
the processor will be inactive during the
oscillator frequency change.
BOR is unknown on Power-on Reset. It
must then be set by the user and checked
on subsequent RESETS to see if BOR is
clear, indicating a brown-out has occurred.
The BOR status bit is a don't care and is
not necessarily predictable if the brown-out
circuit is disabled (by clearing the BODEN
bit in the Configuration word).
REGISTER 2-6:
POWER CONTROL REGISTER (PCON: 8Eh)
U-0
U-0
U-0
R/W-q
R/W-1
U-0
R/W-q
R/W-q
—
—
—
WDTON
OSCF
—
POR
BOR
bit 7
bit 0
bit 7-5
Unimplemented: Read as '0'
bit 4
WDTON: WDT Software Enable bit
If WDTE bit (Configuration Word <3>) = 1:
This bit is not writable, always reads ‘1’
If WDTE bit (Configuration Word <3>) = 0:
1 = WDT is enabled
0 = WDT is disabled
bit 3
OSCF: Oscillator Speed INTRC Mode bit
1 = 4 MHz typical
0 = 37 kHz typical
All other oscillator modes (X = Ignored)
bit 2
Unimplemented: Read as '0'
bit 1
POR: Power-on Reset Status bit
1 = No Power-on Reset occurred
0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)
bit 0
BOR: Brown-out Reset Status bit
1 = No Brown-out Reset occurred
0 = A Brown-out Reset occurred
Legend:
q = Value depends on conditions
DS41171B-page 22
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
’1’ = Bit is set
’0’ = Bit is cleared
Preliminary
x = Bit is unknown
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
2.9
PCL and PCLATH
2.11
INDF
The program counter (PC) specifies the address of the
instruction to fetch for execution. The PC is 13-bits
wide. The low byte is called the PCL register. This register is readable and writable. The high byte is called
the PCH register. This register contains the PC<12:8>
bits and is not directly readable or writable. All updates
to the PCH register occur through the PCLATH register.
The INDF register is not a physical register. Addressing
INDF actually addresses the register whose address is
contained in the FSR register (FSR is a pointer). This is
known as indirect addressing.
2.9.1
A simple program to clear RAM locations 20h-2Fh
using indirect addressing is shown in Example 2-1.
PROGRAM MEMORY PAGING
PIC16C781/782 devices are capable of addressing a
continuous 8K word block of program memory. The
CALL and GOTO instructions provide only 11 bits of
address to allow branching within any 2K program
memory page. When performing a CALL or GOTO
instruction, the upper 2 bits of the address are provided
by PCLATH<4:3>. When performing a CALL or GOTO
instruction, the user must ensure that the page select
bits are programmed so that the desired program memory page is addressed. A return instruction pops a PC
address off the stack onto the PC register. Therefore,
manipulation of the PCLATH<4:3> bits is not required
for the return instructions (which POPs the address
from the stack).
2.10
Stack
The stack allows a combination of up to 8 program calls
and interrupts to occur. The stack contains the return
address from this branch in program execution.
Mid-range devices have an 8-level deep x 13-bit wide
hardware stack. The stack space is not part of either
program or data space and the stack pointer is not
readable or writable. The PC is PUSHed onto the stack
when a CALL instruction is executed, or an interrupt
causes a branch. The stack is POPed in the event of a
RETURN, RETLW, or a RETFIE instruction execution.
PCLATH is not modified when the stack is PUSHed or
POPed.
Reading INDF itself, indirectly (FSR = 0), produces
00h. Writing to the INDF register indirectly results in a
no operation (although STATUS bits may be affected).
EXAMPLE 2-1:
NEXT
0x20
FSR
INDF
FSR
FSR,4
NEXT
;initialize pointer
; to RAM
;clear INDF register
;inc pointer
;all done?
;NO, clear next
CONTINUE
:
;YES, continue
An effective 9-bit address is obtained by concatenating
the 8-bit FSR register and the IRP bit (STATUS<7>), as
shown in Figure 2-5.
FIGURE 2-4:
LOADING OF PC IN
DIFFERENT SITUATIONS
PCH
PCL
8 7
12
8
PCLATH<4:0>
5
0 Instruction with
PCL as
Destination
ALU
PCLATH
12
After the stack has been PUSHed eight times, the ninth
push overwrites the value that was stored from the first
push. The tenth push overwrites the second push (and
so on).
 2001-2013 Microchip Technology Inc.
movlw
movwf
clrf
incf
btfss
goto
HOW TO CLEAR RAM
USING INDIRECT
ADDRESSING
Preliminary
PCL
PCH
1110
0
8 7
GOTO, CALL
PCLATH<4:3>
2
11
Opcode <10:0>
PCLATH
DS41171B-page 23
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PIC16C781/782
FIGURE 2-5:
DIRECT/INDIRECT ADDRESSING
Direct Addressing
RP1:RP0
6
Bank Select
Indirect Addressing
From Opcode
0
7
IRP
FSR Register
Bank Select
Location Select
00
01
10
0
Location Select
11
00h
80h
100h
180h
7Fh
FFh
17Fh
1FFh
Data
Memory(1)
Bank 0
Bank 1
Bank 2
Bank 3
Note 1: For register file map detail, see Figure 2-3.
2.12
Effect of RESET on Core Registers
Refer to Table 2-2 for the effect of a RESET operation
on core registers.
TABLE 2-2:
Address
EFFECT OF RESET ON CORE REGISTERS
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Value on
all other
RESETS(1)
Bank 0
00h
INDF
Addressing this location uses contents of FSR to address data memory (not a physical register)
0000 0000 0000 0000
02h
PCL
Program Counter’s (PC) Least Significant Byte
0000 0000 0000 0000
04h
FSR
Indirect Data Memory Address Pointer
xxxx xxxx uuuu uuuu
0Ah
PCLATH
0Ch
—
—
—
Write Buffer for the upper 5 bits of the Program Counter
PIR1
LVDIF
ADIF
C2IF
C1IF
—
—
—
TMR1IF
81h
OPTION_REG
RBPU
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
xxxx xxxx 1111 1111
83h
STATUS
IRP
RP1
RP0
TO
PD
Z
DC
C
0001 1xxx 000q quuu
---0 0000 ---0 0000
0000 ---0 0000 ---0
Bank 1
8Bh
INTCON
8Ch
PIE1
8Eh
PCON
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x 0000 000u
LVDIE
ADIE
C2IE
C1IE
—
—
—
TMR1IE
0000 ---0 0000 ---0
—
—
—
WDTON
OSCF
—
POR
BOR
---q 1-qq ---q 1-qq
Legend:
Note
x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as '0'.
Shaded locations are unimplemented, read as ‘0’.
1: Other (non power-up) RESETS include external RESET through MCLR and Watchdog Timer Reset.
DS41171B-page 24
Preliminary
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PIC16C781/782
3.0
I/O PORTS
Most pins for the I/O ports are multiplexed with an alternate function for 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.
to prevent unnecessary current drawn from the power
supply. The Analog Select register (ANSEL) allows the
user to individually select the Digital/Analog mode on
these pins. When the Analog mode is active, the port
pin always reads as a logic 0.
Additional information on I/O ports may be found in the
PIC Mid-Range Reference Manual (DS33023)
3.1
Note 1: On a Power-on Reset, the ANSEL register configures these mixed signal pins as
Analog mode: RA<3:0>, RB<3:0>.
I/O Port Analog/Digital Mode
2: If a pin is configured as Analog mode, the
pin always reads '0', even if the digital output is active.
The PIC16C781/782 has two I/O ports: PORTA and
PORTB. Some of these port pins are mixed signal (can
be digital or analog). When an analog signal is present
on a pin, the pin must be configured as an analog input
REGISTER 3-1:
ANALOG SELECT REGISTER (ANSEL: 9Dh)
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 7-0
bit 0
ANS<7:0>: Select Analog Input Function on AN<7:0> bits
1 = Analog input
0 = Digital I/O
Note:
Setting a pin to an analog input disables the digital input buffer. The corresponding
TRIS bit should be set to input mode when using pins as analog inputs.
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
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 25
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PIC16C781/782
3.2
PORTA and the TRISA Register
EXAMPLE 3-1:
PORTA is an 8-bit wide, bi-directional port with the
exception of RA0, RA1 and RA5, which are inputs only.
The corresponding data direction register is TRISA.
Setting a TRISA bit (= 1) makes the corresponding
PORTA pin an input (i.e., disables the digital output).
Clearing a TRISA bit (= 0) makes the corresponding
PORTA pin an output (i.e., disables the digital output).
Reading the PORTA register reads the status of the
pins, whereas writing to it, writes to the port latch. All
write operations are read-modify-write operations.
Therefore, a write to a port implies that the port pins are
read, this value is then modified and written to the port
data latch.
;*
;*
;*
;*
;*
;*
;*
;*
;*
This code block will configure PORTA
as follows
RA<7:4>
digital outputs
RA<3:2>
digital inputs
RA<1:0>
analog inputs
RB<3:0>
digital I/O
Note 1: RB<3:0> configured as digital I/O
Note 2: RA<7:6> availability depends on
the oscillator selection
BANKSEL
CLRF
BANKSEL
MOVLW
Pins RA<3:0> are multiplexed with analog functions:
MOVWF
• Analog inputs AN<3:0> to the A/D Converter.
• VREF1 and VREF2 inputs to the comparators.
• OPAMP inverting/non-inverting inputs.
Note:
MOVLW
MOVWF
When the analog peripherals are using any
of these pins as analog input/output, the
ANSEL register must have the proper
value to individually select the Analog
mode of the corresponding pins.
Pins RA<7:4> are multiplexed with digital functions:
• Pin RA4 is multiplexed with the TMR0 module
clock input.
• Pin RA5 is multiplexed with the device RESET
(MCLR) and programming input (VPP) function.
• Pins RA6 and RA7 are multiplexed with the
oscillator/clock I/O functions. RA6 can also be
configured as the TMR1 clock input.
PORTA has the following I/O characteristics:
• RA0, RA1, and RA5 are input only.
• RA4 is an open drain output. All other PORTA
pins have full CMOS buffer outputs.
• All PORTA pins have Schmitt trigger inputs.
DS41171B-page 26
INITIALIZING PORTA
3.2.1
PORTA
PORTA
;
;
;
TRISA
;
B’00001111’;
;
TRISA
;
;
B’00000011’;
;
ANSEL
;
;
Select Bank 0
Preset PORTA data
reg
Select Bank 1
Digital I/O
config data
Configure PORTA
digital
Analog I/O config
data
Configure PORTA
analog
TRISA, ANSEL, AND CONTROL
PRECEDENCE
The ANSEL and TRISA registers are the primary software controls for the configuration of PORTA pins.
TRISA bits tri-state the output drivers of PORTA, and
ANSEL register bits control the digital input buffers. It is
important to program both registers when configuring a
mixed signal port pin, as most peripherals cannot override the TRISA and ANSEL registers control. Even if a
peripheral has the ability to override control of the
TRISA and ANSEL registers, it is good programming
practice to program both registers appropriately.
There are specific cases in which the TRISA and
ANSEL registers can be overridden by a peripheral or
a configuration bit, see Figures 3-1 through 3-8 for
details.
Note:
Preliminary
Crystal (LP, XT and HS) oscillator configurations use pin RA6/OSC2/CLKOUT/
T1CKI as OSC2. In these modes, setting
or clearing TRISA<6> will have no effect
and the pin will read as a zero (0).
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 27 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
FIGURE 3-1:
BLOCK DIAGRAM OF RA0/AN0/OPA+ PIN
VDD
RA0/AN0/OPA+
RD ANSEL
VSS
RD TRISA
VSS
Data Bus
ANSEL Reg.
Q
D
WR ANSEL
CK
Q
Data Reg.
Q
D
EN
RD PORTA
Analog Function Enable
AN0/OPA+ (see Figure 1-3)
ANSEL<0>
TRISA<0>
FUNCTION
PORTA<0> READ
0
x
Digital In
Pin
1
x
Analog In
0
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 27
PIC16C781.book Page 28 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
FIGURE 3-2:
BLOCK DIAGRAM OF RA1/AN1/OPA- PIN
VDD
RA1/AN1/OPA-
RD ANSEL
VSS
RD TRISA
VSS
Data Bus
ANSEL Reg.
D
WR ANSEL
CK
Q
Q
Data Reg.
D
Q
EN
RD PORTA
Analog Function Enable
AN1/OPA- (see Figure 1-3)
DS41171B-page 28
ANSEL<1>
TRISA<1>
FUNCTION
PORTA<1> READ
0
x
Digital In
Pin
1
x
Analog In
0
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 29 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
FIGURE 3-3:
BLOCK DIAGRAM OF RA2/AN2/VREF2 PIN
RD ANSEL
Data Bus
Data Reg.
D
Q
VDD
VDD
WR PORTA
CK
Q
P
RA2/AN2/VREF2
TRIS Reg.
D
WR TRISA
CK
Q
N
Q
VSS
VSS
RD TRISA
ANSEL Reg.
D
WR ANSEL
Q
CK
Q
Data Reg.
Q
D
EN
RD PORTA
Analog Function Enable
AN2/VREF2 (see Figure 1-3)
ANSEL<2>
TRISA<2>
FUNCTION
PORTA<2> READ
0
1
Digital In
Pin
0
0
Digital Out
Pin
1
x
Analog In
0
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 29
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PIC16C781/782
FIGURE 3-4:
BLOCK DIAGRAM OF RA3/AN3/VREF1 PIN
RD ANSEL
Data Bus
Data Reg.
D
Q
VDD
VDD
WR PORTA
CK
Q
RA3/AN3/VREF1
P
TRIS Reg.
D
WR TRISA
CK
Q
N
Q
VSS
VSS
RD TRISA
ANSEL Reg.
D
WR ANSEL
CK
Q
Q
Data Reg.
Q
D
EN
RD PORTA
Analog Function Enable
AN3/VREF1 (see Figure 1-3)
DS41171B-page 30
ANSEL<3>
TRISA<3>
FUNCTION
PORTA<3> READ
0
1
Digital In
Pin
0
0
Digital Out
Pin
1
x
Analog In
0
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
FIGURE 3-5:
BLOCK DIAGRAM OF RA4/T0CKI PIN
Data Reg.
Data Bus
D
WR PORTA
Q
CK
Q
RA4/T0CKI
TRIS Reg.
D
WR TRISA
CK
Q
N
Q
Vss
Vss
RD TRISA
Data Reg.
Q
D
EN
RD PORTA
TMR0 Clock Input
TRISA<4>
PORTA<4>
FUNCTION
PORTA<4> READ
1
x
Digital In
Pin
0
0
0 Output
Pin
0
1
Hi-Z Output
Pin
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 31
PIC16C781.book Page 32 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
FIGURE 3-6:
BLOCK DIAGRAM OF RA5/MCLR/VPP PIN
MCLRE
RA5/MCLR/VPP
To MCLR Circuit
MCLR Filter
Program Mode
HV Detect
VSS
Data Bus
VSS
RD TRISA
Data Reg.
Q
D
EN
RD PORTA
MCLRE(1)
TRISA<5>
FUNCTION
PORTA<5> READ
Internal
x
Digital In
Pin
External
x
MCLR
0
Note 1: See Configuration Word <5>, Register 14-1.
DS41171B-page 32
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 33 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
FIGURE 3-7:
BLOCK DIAGRAM OF RA6/OSC2/CLKOUT/T1CKI PIN
(INTRC w/ CLKOUT) or (RC w/ CLKOUT)
OSC1
CLKOUT (FOSC/4)
Oscillator
Circuit
1
FOSC<2:0>(1)
0
VDD
T1OSCEN
RA6/OSC2/CLKOUT/T1CKI
Data Reg.
Data Bus
D
WR PORTA
VDD
Q
CK
VSS
P
Q
(INTRC) or (RC)
TRIS Reg.
D
Q
WR TRISA
CK
(see Table)
N (INTRC w/o CLKOUT) or
(RC w/o CLKOUT) or (EC)
Q
(INTRC w/ CLKOUT) or
(RC w/ CLKOUT)
VSS
RD TRISA
Data Reg.
Q
D
EN
RD PORTA
T1CKI
OSC MODE(1)
TMR1 OSCILLATOR
PIN FUNCTION
T1CKI
LP, XT, HS
N/A
OSC2
N/A
0
RC,
INTRC w/ CLKOUT
N/A
CLKOUT
N/A
0
INTRC w/o CLKOUT
Enabled
OSC2 (TMR1)
N/A
0
INTRC w/o CLKOUT
Disabled
Digital I/O
Available
Pin
RC w/o CLKOUT
N/A
Digital I/O
Available
Pin
EC
N/A
Digital I/O
Available
Pin
N/A = Not Available
w/ = with
PORTA<6> READ
w/o = without
Note 1: See Configuration Word FOSC<2:0>, Register 14-1.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 33
PIC16C781.book Page 34 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
FIGURE 3-8:
BLOCK DIAGRAM OF RA7/OSC1/CLKIN PIN
OSC2
Oscillator
Circuit
FOSC<2:0>(1)
T1OSCEN
VDD
To Chip Clock Drivers
RA7/OSC1/CLKIN
Data Reg.
Data Bus
D
Q
VDD
EC Mode
WR PORTA
CK
P
Q
TRIS Reg.
D
Q
VSS
N
WR TRISA
CK
Q
VSS
(INTRC w/ CLKOUT) or
(INTRC w/o CLKOUT)
RD TRISA
Data Reg.
Q
D
EN
RD PORTA
OSC MODE(1)
TMR1 OSCILLATOR
PIN FUNCTION
LP, XT, HS
N/A
OSC1
0
RC
N/A
OSC1
0
PORTA<7> READ
EC
N/A
CLKIN
0
INTRC
Enabled
OSC1 (TMR1)
0
INTRC
Disabled
Digital I/O
Pin
N/A = Not Available
Note 1: See Configuration Word FOSC<2:0>, Register 14-1.
TABLE 3-1:
Address
05h
85h
9Dh
Legend:
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Value on all
other RESETS
PORTA
RA7 RA6
RA5
RA4 RA3 RA2 RA1 RA0
xxxx 0000
uuuu 0000
TRISA
PORTA Data Direction Register
1111 1111
1111 1111
AN6
AN5
AN4 AN3 AN2 AN1 AN0
1111 1111
1111 1111
ANSEL AN7
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTA.
DS41171B-page 34
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 35 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
3.3
PORTB and the TRISB Register
PORTB is an 8-bit wide, bi-directional port. The corresponding data direction register is TRISB. Setting a
TRISB bit (= 1) makes the corresponding PORTB pin
an input (i.e., puts the corresponding output driver into
a Hi-Impedance mode). Clearing a TRISB bit (= 0)
makes the corresponding PORTB pin an output (i.e.,
puts the contents of the output latch on the selected
pin.
EXAMPLE 3-2:
BANKSEL
MOVLW
MOVWF
MOVLW
MOVWF
PORTB
PORTB
;
;
;
TRISB
;
B’11001111’ ;
;
TRISB
;
;
B’00000011’ ;
;
ANSEL
;
;
3.3.1
Select Bank 0
Preset PORTB data
reg.
Select Bank 1
Digital I/O
config data
Configure PORTB
digital
Analog I/O config
data
Configure PORTB
analog
The RB0 pin can be configured as:
•
•
•
•
The RB3 pin is multiplexed with two analog functions:
ADC/Comparator Analog Input AN7, and the output of
the OPA module. When the pin is used as analog I/O,
the ANSEL register must have bit 7 set to select the
Analog mode of the pin.
Pins RB<7:6> are multiplexed with the outputs of the
two on-board comparators, the outputs of the PSMC
module, and the clock gate input for Timer1. Note,
when enabled, these peripherals override the PORTB
data register; however, TRISB retains control of output
drivers. Therefore, TRISB<7:6> must be programmed
appropriately for Comparator and PSMC outputs to
operate.
INITIALIZING PORTB
;* This code block will configure PORT B
;* as follows
;* RB<7:6> analog inputs
;* RB<5:4> digital inputs
;* RB<3:2> digital inputs
;* RB<1:0> digital inputs
;* RA<3:0> digital I/O
BANKSEL
CLRF
Pin RB2 is multiplexed with the analog function ADC/
Comparator Input AN6. When the pin is used as an
analog input, the ANSEL register must have bit 6 to
select the Analog mode for the pin.
Digital I/O
ADC/Comparator Analog Input (AN4)
External Interrupt (INT)
Voltage Reference Output (VR)
When the pin is used as an analog I/O, the ANSEL register must have bit 4 set to configure the RB0 pin as an
analog input.
Pin RB1 is multiplexed with two analog functions: ADC/
Comparator Analog Input AN5, and the output of the
DAC. When the pin is used as an analog I/O, the
ANSEL register must have bit 5 set to configure the
RB1 pin as an analog I/O.
Each of the PORTB pins has an internal weak pull-up
resistance, which can be individually enabled from the
WPUB register. A single global enable bit, RBPU
(OPTION_REG<7>), can turn on/off all of the selected
pull-ups. Clearing the RBPU bit (OPTION_REG<7>)
enables the weak pull-up resistors (see Register 3-2).
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.
3.3.2
PORTB INTERRUPT-ON-CHANGE
Each of the PORTB pins, if configured as input, has the
ability to generate an interrupt-on-change. To enable
the interrupt-on-change feature, the corresponding bit
must be set in the IOCB register (see Register 3-3).
The RBIE bit in the INTCON register functions as a
global enable bit to turn on/off the interrupt-on-change
feature. The selected inputs are compared to the old
value latched on the last read of PORTB. The ”mismatch” outputs are OR-ed together to generate the RB
Port Change Interrupt with flag bit RBIF (INTCON<0>).
The IOCB interrupt can also awaken the device from
SLEEP. The user, in the Interrupt Service Routine,
must clear the interrupt in the following manner:
a)
b)
 2001-2013 Microchip Technology Inc.
PORTB WEAK PULL-UP
Preliminary
A read or write to PORTB. This copies the current state into the latch and ends the mismatch
condition.
Clear flag bit RBIF.
DS41171B-page 35
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REGISTER 3-2:
WEAK PULL-UP PORTB REGISTER (WPUB: 95h)
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
WPUB7
WPUB6
WPUB5
WPUB4
WPUB3
WPUB2
WPUB1
WPUB0
bit7
bit 7-0
bit0
WPUB<7:0>: PORTB Weak Pull-Up Control bits
1 = Weak pull-up enabled for corresponding pin
0 = Weak pull-up disabled for corresponding pin
Note 1: For the WPUB register setting to take effect, the RBPU bit in the OPTION_REG
register must be cleared.
2: The weak pull-up device is automatically disabled if the pin is in output mode, i.e.,
(TRISB = 0) for corresponding pin.
Legend:
REGISTER 3-3:
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
INTERRUPT-ON-CHANGE PORTB REGISTER (IOCB: 96h)
R/W-1
R/W-1
R/W-1
R/W-1
R/W-0
R/W-0
R/W-0
R/W-0
IOCB7
IOCB6
IOCB5
IOCB4
IOCB3
IOCB2
IOCB1
IOCB0
bit7
bit 7-0
bit0
IOCB<7:0>: Interrupt-on-Change PORTB Control bits
1 = Interrupt-on-change enabled for corresponding pin
0 = Interrupt-on-change disabled for corresponding pin
Note 1: The interrupt enable bits, GIE and RBIE in the INTCON register, must be set for individual interrupts to be recognized.
Legend:
3.3.3
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
’1’ = Bit is set
’0’ = Bit is cleared
TRISB, ANSEL, AND CONTROL
PRECEDENCE
The ANSEL and TRISB registers are the primary controls for the configuration of PORTB pins. TRISB tristates the output drivers of PORTB, and the ANSEL
register disables the input buffers. It is important to program both registers when configuring a port pin, since
most peripherals do not have precedence over the
TRISB and ANSEL registers’ control of the pin. Even if
a peripheral has the ability to override the control of the
TRISB and ANSEL registers, it is good practice to program both registers appropriately.
DS41171B-page 36
x = Bit is unknown
Note 1: Upon RESET, the ANSEL register configures the RB<3:0> pins as analog inputs.
Preliminary
2: When programmed as analog inputs,
RB<3:0> pins will read as ‘0’.
3: There are specific cases in which the
functions of the TRISB and ANSEL registers can be overridden by a peripheral or
configuration word (see Figure 3-9
through Figure 3-16 for details).
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
FIGURE 3-9:
BLOCK DIAGRAM OF RB0/INT/AN4/VR PIN
VREN
VROE
VR Output
WPUB Reg.
Data Bus
WR WPUB
D
Q
CK
Q
VDD
RD WPUB
RBPU
P Weak
Pull-up
PORTB Reg.
WR PORTB
D
Q
CK
Q
VDD
P
TRIS Reg.
WR TRISB
D
Q
CK
Q
VDD
RB0/INT/AN4/VR
N
VSS
VSS
RD TRISB
ANSEL Reg.
WR ANSEL
D
Q
CK
Q
TTL
RD ANSEL
IOCB Reg.
WR IOCB
D
Q
CK
Q
Set
RBIF
...
Q
From other
RB<7:0> pins
RD IOCB
Q
D
EN
Q1
D
Q
ENEN
D
Q3
EN
RD PORTB
INT Input
Analog Function Enable
AN4/VR
VREN & VROE
ANSEL<4>
TRISB<0>
FUNCTION
PORTB<0> READ
0
0
1
Digital In
Pin
0
0
0
Digital Out
Pin
0
1
x
Analog In
0
1
x
x
Analog Out
0
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 37
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FIGURE 3-10:
BLOCK DIAGRAM OF RB1/AN5/VDAC PIN
DAON
DAOE
WPUB Reg.
Data Bus
WR WPUB
D
Q
CK
Q
VDAC Output
VDD
RD WPUB
RBPU
P Weak
Pull-up
PORTB Reg.
D
WR PORTB
CK
Q
VDD
Q
P
TRIS Reg.
D
Q
CK
Q
WR TRISB
VDD
RB1/AN5/VDAC
N
VSS
VSS
RD TRISB
ANSEL Reg.
WR ANSEL
D
Q
CK
Q
TTL
RD ANSEL
IOCB Reg.
WR IOCB
D
Q
CK
Q
Set
RBIF
...
Q
From other
RB<7:0> pins
D
Q1
EN
RD IOCB
Q
D
Q
EN
EN
D
Q3
EN
RD PORTB
Analog Function Enable
AN5/VDAC
DAON & DAOE
ANSEL<5>
TRISB<1>
FUNCTION
PORTB<1> READ
0
0
1
Digital In
Pin
0
0
0
Digital Out
Pin
0
1
x
Analog In
0
1
x
x
Analog Out
0
DS41171B-page 38
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
FIGURE 3-11:
BLOCK DIAGRAM OF RB2/AN6 PIN
WPUB Reg.
Data Bus
D
Q
CK
Q
WR WPUB
VDD
RBPU
P Weak
Pull-up
RD WPUB
VDD
PORTB Reg.
D
WR PORTB
Q
CK
VDD
P
RB2/AN6
Q
N
TRIS Reg.
D
Q
CK
Q
WR TRISB
VSS
VSS
RD TRISB
ANSEL Reg.
D
Q
CK
Q
WR ANSEL
RD ANSEL
TTL
IOCB Reg.
D
Q
CK
Q
WR IOCB
Set
RBIF
...
Q
From other
RB<7:0> pins
D
EN
Q1
RD IOCB
Q
D
ENEN
Q
D
Q3
EN
RD PORTB
Analog Function Enable
AN6
ANSEL<6>
TRISB<2>
FUNCTION
PORTB<2> READ
0
1
Digital In
Pin
0
0
Digital Out
Pin
1
x
Analog In
0
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 39
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PIC16C781/782
FIGURE 3-12:
BLOCK DIAGRAM OF RB3/AN7/OPA PIN
CAL_ACTIVE
OPAON
OPA
Output
WPUB Reg.
Data Bus
D
Q
CK
Q
VDD
WR WPUB
RBPU
Weak
P Pull-up
RD WPUB
VDD
PORTB Reg.
WR PORTB
D
Q
CK
Q
VDD
P
RB3/AN7/OPA
N
TRIS Reg.
WR TRISB
D
Q
CK
Q
VSS
VSS
RD TRISB
ANSEL Reg.
WR ANSEL
D
Q
CK
Q
RD ANSEL
TTL
IOCB Reg.
WR IOCB
D
Q
CK
Q
Set
RBIF
...
Q
From other
RB<7:0> pins
RD IOCB
Q
D
Q1
EN
D
EN
EN
Q
RD PORTB
D
Q3
EN
Analog Function Enable
AN7/OPA
OPA MODULE
ANSEL<7>
ADC/C1/C2 INPUT
FUNCTION
PORTB<3> READ
0
Digital
Digital I/O
Pin
1
Analog
Analog In
0
0
1
Analog
OPA Output
0
1
1
Analog HI-Z
Calibration
0
OPAON
CAL_ACTIVE
0
x
0
x
1
1
Analog HI-Z = No internal drive on pin (analog input) during calibration.
DS41171B-page 40
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
FIGURE 3-13:
BLOCK DIAGRAM OF RB4 PIN
WPUB Reg.
Data Bus
D
Q
CK
Q
WR WPUB
VDD
RBPU
P Weak
Pull-up
RD WPUB
VDD
PORTB Reg.
D
Q
CK
Q
WR PORTB
VDD
P
RB4
N
TRIS Reg.
WR TRISB
D
Q
CK
Q
VSS
VSS
RD TRISB
TTL
RD IOCB
IOCB Reg.
D
WR IOCB
Q
CK
Q
Set
RBIF
...
Q
From other
RB<7:0> pins
Q
D
EN
Q1
D
EN
EN
Q
RD PORTB
D
Q3
EN
TRISB<4>
FUNCTION
PORTB<4> READ
0
Digital Out
Pin
1
Digital In
Pin
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 41
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PIC16C781/782
FIGURE 3-14:
BLOCK DIAGRAM OF RB5 PIN
WPUB Reg.
Data Bus
WR WPUB
D
Q
CK
Q
VDD
RBPU
P Weak
Pull-up
RD WPUB
VDD
PORTB Reg.
D
WR PORTB
Q
CK
VDD
P
RB5
Q
N
TRIS Reg.
WR TRISB
D
Q
CK
Q
VSS
VSS
RD TRISB
TTL
RD IOCB
IOCB Reg.
WR IOCB
D
Q
CK
Q
Set
RBIF
...
Q
From other
RB<7:0> pins
Q
Q1
D
ENEN
RD PORTB
DS41171B-page 42
D
EN
Q
D
Q3
EN
TRISB<5>
FUNCTION
0
Digital Out
PORTB<5> READ
Pin
1
Digital In
Pin
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
FIGURE 3-15:
BLOCK DIAGRAM OF RB6/C1/PSMC1A PIN
C1OE
SMCON
PSMC1A
C1OUT
WPUB Reg.
Data Bus
WR WPUB
D
Q
CK
Q
VDD
RBPU
P Weak Pull-up
RD WPUB
Data Reg.
D
Q
VDD
VDD
WR PORTB
CK
P
Q
RB6/C1/PSMC1A
TRIS Reg.
D
Q
CK
Q
N
VSS
WR TRISB
VSS
RD TRISB
TTL
RD PORTB
RD IOCB
IOCB Reg.
D
Q
CK
Q
WR IOCB
Serial Programming Clock
Q
D
Q1
EN
Set RBIF
Q
From other
RB<7:0> pins
D
EN
RD Port
Q3
PSMC SMCON
COMPARATOR C1OE
PORTB TRISB<6>
x
x
1
Digital In
0
0
0
Digital Out
0
1
0
C1OUT
1
x
0
PSMC1A
 2001-2013 Microchip Technology Inc.
Preliminary
FUNCTION
DS41171B-page 43
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PIC16C781/782
FIGURE 3-16:
BLOCK DIAGRAM OF RB7/C2/PSMC1B/T1G PIN
C2OE
SCEN
SMCOM
SMCON
RD WPUB
VDD
RBPU
VDD
P Weak Pull-up
WPUB Reg.
Data Bus
D
WR WPUB
Q
CK
VSS
Data Reg.
WR PORTB
RB7/C2/PSMC1B/T1G
Q
D
Q
CK
Q
TRIS Reg.
D
Q
CK
Q
C2OUT
VDD
WR TRISB
P
PSMC1B
N
RD TRISB
SC Switch
VSS
RD IOCB
TTL
RD PORTB
IOCB Reg.
WR IOCB
D
Q
CK
Q
Serial Programming Data
and Timer1 Gate
D
Q
Q1
EN
Set RBIF
Q
D
From other
RB<7:0> pins
RD Port
Q3
EN
PSMC MODULE
SMCON
SMCOM
SCEN
COMPARATOR
C2OE
PORTB TRISB<7>
FUNCTION
x
x
x
x
1
Digital In
0
x
x
0
0
Digital Out
1
0
0
0
0
Digital Out
0
x
x
1
0
C2OUT
1
0
0
1
0
C2OUT
1
0
1
x
0
Slope Compensation
1
1
x
x
0
PSMC1B
DS41171B-page 44
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
TABLE 3-2:
Address
06h
86h
SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
Name
PORTB
TRISB
OPTION_REG
Value on:
POR, BOR
Value on
all other
RESETS
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3 Bit 2 Bit 1 Bit 0
RB7
RB6
RB5
RB4
RB3
RB2
RB1 RB0 xxxx 0000 uuuu 0000
PSA
PS2
PS1
PORTB Data Direction Register
RBPU
1111 1111 1111 1111
81h
95h
WPUB
PORTB Weak Pull-up Control
1111 1111 1111 1111
96h
IOCB
PORTB Interrupt-on-Change Control
1111 0000 1111 0000
INTEDG
T0CS
T0SE
PS0 1111 1111 1111 1111
9Dh
ANSEL
AN7
AN6
AN5
AN4 AN3 AN2 AN1 AN0 1111 1111 1111 1111
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTB.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 45
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PIC16C781/782
NOTES:
DS41171B-page 46
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
4.0
PROGRAM MEMORY READ
(PMR)
Program memory is readable during normal operation
(full VDD range). It is read by indirect addressing
through the following Special Function Registers:
•
•
•
•
•
PMCON1: Control
PMDATH: Data High
PMDATL: Data Low
PMADRH: Address High
PMADRL: Address Low
4.1
PMCON1 Register
PMCON1 is the control register for program memory
accesses.
Control bit RD initiates a read operation. This bit cannot
be cleared, only set, in software. It is cleared in hardware at completion of the read operation.
When interfacing to the program memory block, the
PMDATH and PMDATL registers form a 2-byte word,
which holds the 14-bit data. The PMADRH and
PMADRL registers form a 2-byte word, which holds the
12-bit address of the program memory location being
accessed. Mid-range devices have up to 8K words of
program EPROM with an address range from 0h to
REGISTER 4-1:
3FFFh. When the device contains less memory than
the full address range of the PMADRH:PMARDL registers, the Most Significant bits of the PMADRH register
are ignored.
4.2
PMDATH and PMDATL Registers
The PMDATH:PMDATL registers are loaded with the
contents of program memory addressed by the
PMADRH and PMADRL registers upon completion of a
Program Memory Read command.
PROGRAM MEMORY READ CONTROL REGISTER 1 (PMCON1: 18Ch)
R-1
U-0
U-0
U-0
U-0
U-0
U-0
R/S-0
Reserved
—
—
—
—
—
—
RD
bit7
bit0
bit 7
Reserved: Read as ‘1’
bit 6-1
Unimplemented: Read as '0
bit 0
RD: Read Control bit
1 = Initiates a Program memory read (read takes 2 cycles, RD is cleared in hardware)
0 = Reserved
Legend:
S = Settable bit
REGISTER 4-2:
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
PROGRAM MEMORY DATA HIGH (PMDATH: 10Eh)
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
PMD13
PMD12
PMD11
PMD10
PMD9
PMD8
bit7
bit0
bit 7-6
Unimplemented: Read as '0
bit 5-0
PMD<13:8>: Program Memory Data bits
The value of the program memory word pointed to by PMADRH and PMADRL after a program
memory read command.
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
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 47
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PIC16C781/782
REGISTER 4-3:
PROGRAM MEMORY DATA LOW (PMDATL: 10Ch)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
PMD7
PMD6
PMD5
PMD4
PMD3
PMD2
PMD1
PMD0
bit7
bit 7-0
bit0
PMD<7:0>: Program Memory Data bits
The value of the program memory word pointed to by PMADRH and PMADRL after a program
memory read command.
Legend:
REGISTER 4-4:
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
PROGRAM MEMORY ADDRESS HIGH (PMADRH: 10Fh)
U-0
U-0
U-0
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
—
—
—
Reserved
Reserved
PMA10
PMA9
PMA8
bit7
bit0
bit 7-5
Unimplemented: Read as '0'
bit 4-3
Reserved: Read state is not guaranteed
bit 2-0
PMA<10:8>: PMR Address bits
Legend:
REGISTER 4-5:
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
PROGRAM MEMORY ADDRESS LOW (PMADRL: 10Dh)
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
PMA7
PMA6
PMA5
PMA4
PMA3
PMA2
PMA1
PMA0
bit7
bit 7-0
bit0
PMA<7:0>: PMR Address bits
Legend:
DS41171B-page 48
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
’1’ = Bit is set
’0’ = Bit is cleared
Preliminary
x = Bit is unknown
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PIC16C781/782
4.3
Reading the EPROM Program
Memory
in the following instructions. PMDATH and PMDATL
registers hold this value until another read or until
RESET.
To read a program memory location, the user must
write 2 bytes of the address to the PMADRH and
PMADRL registers, then set control bit RD
(PMCON1<0>). Once the read control bit is set, the
Program Memory Read (PMR) controller uses the second instruction cycle after to read the data. This causes
the second instruction immediately following the “BSF
PMCON1,RD” instruction to be ignored. The data is
available, in the very next cycle, in the PMDATH and
PMDATL registers. Therefore, it can be read as 2 bytes
EXAMPLE 4-1:
Note 1: Interrupts must be disabled during the
time from setting PMCON1<0> (RD) to
the second instruction thereafter.
2: The following instructions should not be
used following the start of a PMR read
cycle: CALL, GOTO, BTFSS, BTFSC,
RETFIE, RETURN, SLEEP.
OTP PROGRAM MEMORY READ
;* This code block will read 1 word of program
;* memory at the memory address:
;* PROG_ADDR_HI : PROG_ADDR_LO
;* data will be returned in the variables;
;*
PROG_DATA_HI, PROG_DATA_LO
BANKSEL
MOVLW
MOVWF
MOVLW
MOVWF
PMADRL
PROG_ADDR_LO
PMADRL
PROG_ADDR_HI
PMADRH
; Select Bank 2
;
; Store LSB of address
;
; Store MSB of address
BANKSEL
CLEAR GIE
BCF
BSF
NOP
NOP
BSF
MOVF
MOVWF
MOVF
MOVWF
PMCON1
; Select Bank 3
INTCON, GIE
PMCON1,RD
;
;
;
;
;
;
INTCON, GIE
PMDATL,W
PROG_DATA_LO
PMDATH,W
PROG_DATA_HI
 2001-2013 Microchip Technology Inc.
Turn off INTs
Initiate read
Executed (Fig 4-1)
Ignored (Fig 4-1)
Turn on INTs
Get LSB of word
; Get MSB of word
Preliminary
DS41171B-page 49
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4.4
Program Memory Read With Code
Protect Set
When the device is code protected, the CPU can still
perform the program memory read function.
TABLE 4-1:
Address
SUMMARY OF REGISTERS ASSOCIATED WITH PMR
Value on:
POR, BOR
Value on
all other
RESETS
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
10Ch
PMDATL
PMD7
PMD6
PMD5
PMD4
PMD3
PMD2
PMD1
PMD0 0000 0000 0000 0000
10Dh
PMADRL
PMA7
PMA6
PMA5
PMA4
PMA3
PMA2
PMA1
PMA0 xxxx xxxx uuuu uuuu
10Eh
PMDATH
—
—
PMD13
PMD12
PMD11
PMD10
PMD9
PMD8 --00 0000 --00 0000
10Fh
PMADRH
—
—
—
PMA10
PMA9
PMA8 ---x xxxx ---u uuuu
18Ch
PMCON1
Reserved
—
—
—
—
Reserved Reserved
—
—
RD
1--- ---0 1--- ---0
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PMR.
FIGURE 4-1:
PROGRAM MEMORY READ CYCLE EXECUTION
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Program
Memory
ADDR
PC
INSTR(PC-1)
Executed here
PC+1
BSF PMCON1,RD
Executed here
PC+3
PC+3
PMADRH,PMADRL
INSTR(PC+1)
Executed here
Forced NOP
Executed here
PC+4
PC+5
INSTR(PC+3)
Executed here
INSTR(PC+4)
Executed here
RD bit
PMDATH
PMDATL
Register
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5.0
TIMER0 MODULE
When an external clock input is used for Timer0, it must
meet certain requirements. The requirements ensure
the external clock can be synchronized with the internal
system clock. Also, there is a delay in the actual incrementing of Timer0 after synchronization.
The Timer0 module timer/counter has the following
features:
•
•
•
•
•
•
8-bit timer/counter
Readable and writable
Internal or external clock select
Edge select for external clock
8-bit software programmable prescaler
Interrupt on overflow from FFh to 00h
Additional information on external clock requirements
is available in the PIC Mid-Range Reference Manual,
(DS33023).
EXAMPLE 5-1:
Figure 5-1 is a simplified block diagram of the Timer0
module.
Additional information on timer modules is available in
the PIC Mid-Range Reference Manual, (DS33023).
5.1
INITIALIZING TIMER0
;* This code block will configure Timer0
;* for Polling, internal clock & 1:16
;* prescaler
;*
;* Wait for TMR0 overflow code included
BANKSEL
TMR0
; Select Bank 0
CLRF
TMR0
; Clear Timer0
; Register
Timer0 Operation
Timer0 can operate as either a timer or a counter.
Programming Timer0 is via the OPTION register (see
Register 2-2).
OPTION_REG
MOVLW
MOVWF
B’11000011’
OPTION_REG
; Select Bank 1
; INT on L2H
; Internal clk,
; pscaler 1:16
********************************************
;* Wait for TMR0 overflow
;*
T0_OVFL_WAIT
TBFSS
INTCON,T0IF
; Check for TMR0
; overflow
GOTO
T0_OVFL_WAIT ; If clear, test
; again
BCF
INTCON,T0IF
; Clear interrupt
Timer0 mode is selected by clearing/setting the bit
T0CS (OPTION_REG<5>). In Timer mode (T0CS = 0),
the Timer0 module increments every instruction cycle
(without prescaler). If the TMR0 register is written, the
increment is inhibited for the following two instruction
cycles. The user can work around this by writing an
adjusted value to the TMR0 register.
Counter mode is selected by setting bit T0CS
(OPTION_REG<5>). In Counter mode, Timer0
increments either on every rising, or falling edge of pin
RA4/T0CKI. The incrementing edge is determined by
the Timer0 Source Edge Select bit T0SE
(OPTION_REG<4>). Clearing bit T0SE selects the rising edge, setting selects the falling edge. Restrictions
on the external clock input are discussed below.
FIGURE 5-1:
BANKSEL
TIMER0 BLOCK DIAGRAM
Data Bus
FOSC/4
0
PSOUT
1
1
Programmable
Prescaler
RA4/T0CKI
pin
0
8
Sync with
Internal
Clocks
TMR0
PSOUT
(2 TCY Delay)
T0SE
3
PS<2:0>
PSA
T0CS
Set Interrupt
Flag bit T0IF
on Overflow
Note 1: T0CS, T0SE, PSA, PS<2:0> (OPTION_REG<5:0>).
2: The prescaler is shared with Watchdog Timer (refer to Figure 5-2 for detailed block diagram).
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PIC16C781/782
5.2
Prescaler
5.2.1
An 8-bit counter is available as a prescaler for the
Timer0 module, or as a postscaler for the Watchdog
Timer, respectively (Figure 5-2). For simplicity, this
counter is referred to as “prescaler” throughout this
data sheet.
Note:
Note:
5.3
The PSA and PS<2:0> bits (OPTION_REG<3:0>)
determine the prescaler assignment and prescale ratio.
Clearing bit PSA assigns the prescaler to the Timer0
module. When the prescaler is assigned to the Timer0
module, prescale values of 1:2, 1:4, ..., 1:256 are
selectable.
Setting bit PSA assigns the prescaler to the Watchdog
Timer (WDT). When the prescaler is assigned to the
WDT, prescale values of 1:1, 1:2, ..., 1:128 are selectable.
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (e.g., CLRF TMR0,
MOVWF TMR0, BSF TMR0, x....etc.) will clear the
prescaler. When assigned to WDT, a CLRWDT instruction clears the prescaler along with the WDT.
Note:
The prescaler assignment is fully under software control, i.e., it can be changed “on-the-fly” during program
execution.
There is only one prescaler available
which is mutually exclusively shared
between the Timer0 module and the
Watchdog Timer. Thus, a prescaler assignment for the Timer0 module means that
there is no prescaler for the Watchdog
Timer, and vice-versa.
The prescaler is not readable or writable.
SWITCHING PRESCALER
ASSIGNMENT
To avoid an unintended device RESET, a
specific instruction sequence (shown in the
PIC Mid-Range Reference Manual,
DS33023) must be executed when changing the prescaler assignment from Timer0
to the WDT. This sequence must be followed even if the WDT is disabled.
Timer0 Interrupt
The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h. This overflow sets bit
T0IF (INTCON<2>). The interrupt can be masked by
clearing bit T0IE (INTCON<5>). Bit T0IF must be
cleared in software by the Timer0 module Interrupt Service Routine before re-enabling this interrupt. The
TMR0 interrupt cannot awaken the processor from
SLEEP, since the timer is shut-off during SLEEP.
5.4
Effects of RESET
A device RESET will program Timer0 for an external
clock input on RA4/T0CKI, Hi-Low edge, and no prescaler. The TMR0 register is not cleared.
Writing to TMR0 when the prescaler is
assigned to Timer0 clears the prescaler
count, but does not change the prescaler
assignment.
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FIGURE 5-2:
BLOCK DIAGRAM OF THE TIMER0/WDT PRESCALER
Data Bus
FOSC/4
8
0
1
RA4/T0CKI
pin
Sync
with
Internal
Clocks
1
0
T0SE
TMR0 reg
(2 TCY Delay)
T0CS
Set Interrupt Flag bit
T0IF on Overflow
PSA
0
8-bit Prescaler
8
1
Watchdog
Timer
8 - to - 1 MUX
PS<2:0>
PSA
WDT Enable bit
0
1
PSA
WDT
Time-out
Note: T0CS, T0SE, PSA, PS<2:0> are (OPTION_REG<5:0>).
TABLE 5-1:
Address
REGISTERS ASSOCIATED WITH TIMER0
Name
01h,101h
TMR0
0Bh,8Bh,
10Bh,18Bh
INTCON
81h,181h
OPTION_REG
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Timer0 Register
Value on
all other
RESETS
xxxx xxxx
uuuu uuuu
GIE
ADIF
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x
0000 000u
RBPU
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
1111 1111
1111 1111
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by Timer0.
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NOTES:
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6.0
TIMER1 MODULE WITH GATE
CONTROL
The Timer1 module timer/counter has the following
features:
• 16-bit timer/counter
(two 8-bit registers:TMR1H and TMR1L)
• Readable and writable (both registers)
• Internal or external clock select
• Interrupt on overflow from FFFFh to 0000h
• External enable input (T1G pin with TMR1GE bit = 1)
• Option for Timer1 to use LP oscillator if device is
configured to use INTRC w/o CLKOUT
Timer1 Control register (T1CON) is shown in Register 6-1.
Figure 6-2 is a simplified block diagram of the Timer1
module.
6.1
Timer1 Operation
Timer1 can operate in one of three modes:
1.
2.
3.
EXAMPLE 6-1:
;*
;*
;*
;*
;*
;*
Wait for TMR1 overflow code included
BANKSEL
CLRF
CLRF
MOVLW
MOVWF
BSF
TMR1L
TMR1L
TMR1H
B’01000000’
T1CON
T1CON,TMR1ON
;
;
;
;
;
;
Select Bank 0
Clear TMR1 LSB
Clear TMR1 MSB
Gate, Ps 1:1
Int clk
Enable timer
;********************************************
;* Wait for TMR1 overflow
T1_OVFL_WAIT
BANKSEL PIR1
T1_WAIT
TBFSS
PIR1,TMR1IF
GOTO
T1_WAIT
BCF
16-bit timer with prescaler.
16-bit synchronous counter.
16-bit asynchronous counter.
TIMER1 INITIALIZATION
This code block will configure Timer1 for
Polling, Ext gate of int clk (Fosc/4), &
1:1 prescaler.
PIR1,TMR1IF
; Select Bank 0
;
; Overflow?
; If 0, again
; Clear flag
In Timer mode, Timer1 is incremented on every instruction cycle. In Counter mode, Timer1 is incremented on
the rising edge of the external clock input T1CKI (RA6/
OSC2/CLKOUT/T1CKI). In addition, the Counter mode
clock can be synchronized to the microcontroller clock
or run asynchronously.
In Counter and Timer modes, the counter/timer clock
can be gated by the T1G input.
If an external clock oscillator is needed (and the microcontroller is using INTRC w/o CLKOUT), Timer1 can
use the LP oscillator as a clock source.
Note 1: In Counter mode, the counter increments
on the rising edge of the clock.
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6.2
Control Register T1CON
Control and configuration of Timer1 is by means of the
T1CON register shown in Register 6-1.
T1CKPS<1:0> determines the prescaler value for the
timer. Available prescaler values are:
T1CKPS<1:0>
Prescaler Value
Timer1 is enabled by setting the TMR1ON bit
(T1CON<0>). Clearing TMR1ON stops the timer, but
does not clear the Timer1 register.
The TMR1CS bit (T1CON<1>) determines the Timer
mode. When TMR1CS is set, the timer is configured as
a counter and receives its clock from RA6/OSC2/
CLKOUT/T1CKI. When cleared, the timer is configured
as a timer and its clock is derived from FOSC/4.
Bit 1
Bit 0
1
1
0
0
1
0
1
0
Note:
The T1SYNC bit (T1CON<2>) determines Timer1’s synchronization. If cleared, the timer clock is synchronized
to the system clock. If set, the timer is asynchronous.
The Timer1 clock gate function is enabled by setting
the TMR1GE bit (T1CON<6>). When TMR1GE is set,
the T1G input will control the clock input to the timer/
counter. A low on the T1G input will cause Timer1 to
increment at the clock rate, a high will hold the timer at
its present value.
1:8
1:4
1:2
1:1
To use the LP oscillator as the Timer1
oscillator:
1. TMR1CS must be set.
2. T1OSCEN must be set.
3. The Configuration Word must select
INTRC w/o CLKOUT.
The T1OSCEN bit (T1CON<3>) enables the LP oscillator as a clock source for Timer1. This mode is a
replacement for the regular external oscillator.
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REGISTER 6-1:
TIMER1 CONTROL REGISTER (T1CON: ADDRESS 10h)
U-0
—
R/W-0
R/W-0
R/W-0
TMR1GE T1CKPS1 T1CKPS0
R/W-0
T1OSCEN
R/W-0
R/W-0
R/W-0
T1SYNC TMR1CS TMR1ON
bit 7
bit 0
bit 7
Unimplemented: Read as '0'
bit 6
TMR1GE: Timer1 Gate Enable bit
If TMR1ON = 0:
This bit is ignored
If TMR1ON = 1:
1 = Timer1 is on if T1G pin is low
0 = Timer1 is on
bit 5-4
T1CKPS<1:0>: Timer1 Input Clock Prescale Select bits
11 = 1:8 Prescale value
10 = 1:4 Prescale value
01 = 1:2 Prescale value
00 = 1:1 Prescale value
bit 3
T1OSCEN: LP Oscillator Enable Control bit
If INTRC w/o CLKOUT is selected in the configuration word, oscillator is active:
1 = LP oscillator is enabled for Timer1 clock
0 = LP oscillator is off
Else:
This bit is ignored
bit 2
T1SYNC: Timer1 External Clock Input Synchronization Control bit
TMR1CS = 1:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
TMR1CS = 0:
This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.
bit 1
TMR1CS: Timer1 Clock Source Select bit
1 = External clock from pin RA6/OSC2/CLKOUT/T1CKI (on the rising edge)
0 = Internal clock (FOSC/4)
bit 0
TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1
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
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 57
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PIC16C781/782
FIGURE 6-1:
TIMER1 INCREMENTING EDGE
T1CKI = 1
when TMR1
Enabled
T1CKI = 0
when TMR1
Enabled
Note 1: Arrows indicate counter increments.
2: In Counter mode, a falling edge must be registered by the counter prior to the first incrementing rising edge
of the clock.
FIGURE 6-2:
TIMER1 ON THE PIC16C781/782 BLOCK DIAGRAM
RB7/C2/
PSMC1B/T1G
TMR1ON
TMR1GE
TMR1ON
TMR1GE
Set Flag bit
TMR1IF on
Overflow
To C2 Comparator
Module
TMR1 Clock
TMR1
Synchronized
Clock Input
0
TMR1H
TMR1L
1
RA7/OSC1/CLKIN
RA6/OSC2/
CLKOUT/
T1CKI
INTRC
w/o CLKOUT Mode
LP OSCILLATOR
T1SYNC
1
FOSC/4
Internal
Clock
Prescaler
1, 2, 4, 8
Synchronize
det
0
2
T1CKPS<1:0>
SLEEP Input
TMR1CS
T1OSCEN
LPEN
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6.3
Timer1 Oscillator for the
PIC16C781/782
6.4
When the microcontroller is using INTRC w/o CLKOUT,
Timer1 can enable and use the LP oscillator as the
Timer1 oscillator. When enabled, Timer1 oscillator
operation is solely controlled by the T1OSCEN bit. The
oscillator will operate independently of the TMR1ON
bit, allowing the programmer to start and stop the
Timer/Counter using the TMR1ON bit. The oscillator
will also operate during SLEEP, allowing continuous
timekeeping with Timer1. The electrical requirements
for the LP oscillator, when used as the Timer1 oscillator, are the same as when the oscillator is used in LP
mode.
Note:
Address
Note:
6.5
The oscillator requires a startup and stabilization time before use. Therefore,
T1OSCEN should be set, and a suitable
delay observed, prior to enabling Timer1
(see Section 14.2).
TABLE 6-1:
Name
Timer1 Interrupt
The TMR1 register pair (TMR1H and TMR1L) increments from 0000h to FFFFh and then rolls over to
0000h. When Timer1 rolls over, the TMR1IF bit
(PIR1<0>) is set. To enable an interrupt, the TMR1IE
bit (PIE1<0>), the GIE (INTCON<7>) and the PEIE bit
(INTCON<6>) must be set prior to rollover. To clear the
interrupt, the TMR1IF must be cleared by software prior
to re-enabling interrupts.
When enabling the Timer1 interrupt, the
user should clear both TMR1 registers and
the TMR1IF prior to enabling interrupts.
Effects of RESET
Only POR and BOR Resets clear T1CON, disabling
Timer1. All other RESETS do not affect Timer1.
SUMMARY OF REGISTERS ASSOCIATED WITH TIMER1
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR,
BOR
Value on
all other
RESETS
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000X 0000 000u
LVDIF
ADIF
C2IF
C1IF
—
—
—
TMRIF
0000 ---0 0000 ---0
PIE1
LVDIE
ADIE
C2IE
C1IE
—
—
—
TMRIE
TMR1L
Least Significant Byte of the 16-bit TMR1 Register
xxxx xxxx uuuu uuuu
0Fh
TMR1H
Most Significant Byte of the 16-bit TMR1 Register
xxxx xxxx uuuu uuuu
10h
T1CON
0Bh
INTCON
0Ch
PIR1
8Ch
0Eh
—
0000 ---0 0000 ---0
TMR1GE T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON -000 0000 -uuu uuuu
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by Timer1.
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Preliminary
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NOTES:
DS41171B-page 60
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7.0
VOLTAGE REFERENCE
MODULE (VR)
Setting the VREN flag (REFCON<3>), enables the
module. Following initial start-up, the module should be
allowed to stabilize for best accuracy. See Section 17.0
for information concerning stabilization times and
conditions.
The Voltage Reference module provides an on-chip
nominal 3.072V reference voltage for the following:
• ADC converter
• DAC converter
• VR output on the RB0/INT/AN4/VR pin
To route the reference voltage to the external RB0/INT/
AN4/VR pin, the VROE flag (REFCON<2>) must be
set.
The source for the reference voltage comes from a
bandgap reference.
7.1
Effects of RESET
A device RESET clears the REFCON register, disabling the voltage reference.
The control register for this module is the REFCON
register shown in Register 7-1.
7.2
Note 1: If the VR module is to be used by the
DAC, ADC, or VR output:, the VR module
must
be
enabled
using
VREN
(REFCON<3>).
Registers Associated with VR
A summary of the registers associated with VR is
shown in Table 7-1.
2: When VREN = 1 and VROE = 1, the output driver for RB0/INT/AN4/VR will be
driven tri-state and the analog driver for
the VR output will be enabled. A read of
RB0 will return a ‘0’.
REGISTER 7-1:
VOLTAGE REFERENCE CONTROL REGISTER (REFCON: 9Bh)
U-0
U-0
U-0
U-0
R/W-0
R/W-0
U-0
U-0
—
—
—
—
VREN
VROE
—
—
bit 7
bit 0
bit 7-4
Unimplemented: Read as ‘0’
bit 3
VREN: Voltage Reference Enable bit (VR = 3.072V nominal)
1 = VR reference is enabled
0 = VR reference is disabled
bit 2
VROE: Voltage Reference Output Enable bit
If VREN = 1:
1 = Enabled, VR voltage reference is output on RB0
0 = Voltage reference is not available externally
If VREN = 0:
This bit is ignored
bit 1-0
Unimplemented: Read as ‘0’
Legend:
TABLE 7-1:
Address
09Bh
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
SUMMARY OF REGISTERS ASSOCIATED WITH VR
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
REFCON
—
—
—
—
VREN
VROE
—
—
 2001-2013 Microchip Technology Inc.
Preliminary
Value on:
POR,
BOR
Value on
all other
RESETS
---- 00-- ---- 00--
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8.0
PROGRAMMABLE LOW
VOLTAGE DETECT MODULE
(PLVD)
condition. The time between TA and TB is then available
to the microcontroller for completing a ‘graceful’ powerdown before VDD falls below VB.
The PLVD module monitors the VDD power supply of
the microcontroller and signals the microcontroller
whenever VDD drops below its trip voltage. The signal
acts as an ‘early warning’ of power-down, allowing the
microcontroller to finish any critical ‘housekeeping’
tasks prior to completing power-down.
Figure 8-2 is a simplified block diagram for the PLVD
module, showing the VDD resistor ladder, control register, and voltage comparator.
Note:
Figure 8-1 demonstrates a potential application of the
PLVD module (typical battery operation). At time TA, the
VDD supply voltage (VA) has fallen below the PLVD reference voltage. The PLVD voltage comparator then
sets the LVDIF bit (PIR<7>), indicating a low voltage
FIGURE 8-1:
For low power applications, current drain
can be minimized by enabling the module
only during regular polled testing. When
not in use, the module is disabled by clearing the LVDEN bit (LVDCON<4>), which
also powers down the resistor ladder
between VDD and Vss.
TYPICAL LOW VOLTAGE DETECT APPLICATION
Voltage
VA
VB
Legend:
VA = PLVD trip point
VB = Minimum valid device
operating voltage
Time
8.1
TA
TB
Control Register
The PLVD module is controlled via the LVDCON register shown in Register 8-1.
To enable the module for testing, the LVDEN bit
(LVDCON<4>) must be set. This will enable the onboard voltage reference and connect the resistor ladder between VDD and Vss. Clearing LVDEN will disable
the module and disconnect the resistor ladder from
Vss.
 2001-2013 Microchip Technology Inc.
The trip voltage is set by programming the LVDL<3:0>
bit (LVDCON<3.0>). The voltages available are listed
in Register 8-1. Note that voltages below 2.5V and
above 4.75V are not available and should not be used.
The BGST bit (LVDCON<5>) is a status bit indicating
that the internal reference voltage bandgap has stabilized. No test should be performed until this bit is set.
The low voltage output flag for the PLVD module is the
LVDIF bit (PIR1<6>).
Preliminary
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PIC16C781/782
8.2
Operation
enables this reference whenever it is enabled and provides a stability bit, BGST, to indicate when it has stabilized. The bandgap reference is also enabled by
other modules within the PIC16C781/782 as part of
their operation. Other modules using the bandgap
include the following:
The PLVD indicates a low voltage condition by setting
the LVDIF bit in the PIR1 register. Once set by the
PLVD module, the LVDIF bit will remain set until
cleared by software. For proper indication of a low voltage condition, the user should clear this bit prior to
testing.
• VR module
• BOR module
• OPA calibration module
To test for a low voltage condition, the PLVD module
compares the divided output of VDD against an internal
bandgap reference. The PLVD module automatically
FIGURE 8-2:
LOW VOLTAGE DETECT BLOCK DIAGRAM
VDD
16 to 1 MUX
PLVD Control
Register
LVDEN
DS41171B-page 64
LVDIF
Internally Generated
Reference Voltage
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PIC16C781/782
If another module has enabled the bandgap, then the
reference will be stable when the PLVD module is
enabled and the BGST flag can be ignored. However,
if the bandgap has not been previously enabled, the
LVDIF bit will not be valid until the BGST bit is set (see
Figure 8-3). Systems using the PLVD interrupt should
not enable the interrupt until after the reference is stable to prevent spurious interrupts.
8.2.1
3.
4.
5.
SETTING UP THE PLVD MODULE
The following steps are needed to set up the PLVD
Module:
1.
2.
6.
Ensure that PLVD interrupts are disabled (the
LVDIE bit is cleared, or the GIE bit is cleared).
Enable the PLVD module (set the LVDEN bit in
the LVDCON register).
Wait for the PLVD module to stabilize (the BGST
bit to become set).
Clear the PLVD interrupt flag, which may have
falsely become set until the PLVD module has
stabilized (clear the LVDIF bit).
Enable the PLVD interrupt (set the LVDIE and
the GIE bits).
Write the value to the LV3:LV0 bits (LVDCON
register), which selects the desired PLVD Trip
Point.
FIGURE 8-3:
LOW VOLTAGE DETECT WAVEFORMS
CASE 1:
LVDIF may not be set
VDD
.
VLVD
LVDIF
Enable LVD
Internally Generated
Reference Stable
LVDIF cleared in software
CASE 2:
VDD
VLVD
LVDIF
Enable LVD
Internally Generated
Reference Stable
LVDIF cleared in software
Attempt to clear LVDIF in software
but remains set as LVD condition
still exists
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 65
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PIC16C781/782
REGISTER 8-1:
PROGRAMMABLE LOW VOLTAGE DETECT REGISTER (LVDCON: 9Ch)
U-0
U-0
R-0
R/W-0
R/W-0
R/W-1
R/W-0
R/W-1
—
—
BGST
LVDEN
LV3
LV2
LV1
LV0
bit 7
bit 0
bit 7-6
Unimplemented: Read as '0'
bit 5
BGST: Internal Reference Voltage Stable Flag bit
1 = Reference is stable
0 = Reference is not stable
bit 4
LVDEN: Low Voltage Detect Power Enable bit
1 = Enables PLVD, powers up LVD circuit
0 = Disables PLVD, powers down LVD circuit.
bit 3-0
LV<3:0>: Low Voltage Detection Limit bits
1111 = Reserved
1110 = 4.5V typical
1101 = 4.2V typical
1100 = 4.0V typical
1011 = 3.8V typical
1010 = 3.6V typical
1001 = 3.5V typical
1000 = 3.3V typical
0111 = 3.0V typical
0110 = 2.8V typical
0101 = 2.7V typical
0100 = 2.5V typical
0011 = Below valid operating voltage
0010 = Below valid operating voltage
0001 = Below valid operating voltage
0000 = Below valid operating voltage
Legend:
DS41171B-page 66
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
Preliminary
x = Bit is unknown
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
Example 8-1 shows the configuration of the PLVD module and a sample polling routine to monitor for low voltage conditions.
EXAMPLE 8-1:
PLVD EXAMPLE
;************************************************
;* This code block will configure the PLVD for polling
;* and set the trip point for 4.2 to 4.4 volts
;* Includes polling routine
;*
BANKSEL
BCF
MOVLW
MOVWF
LVDCON
PIE1,LVDIE
B’00011101’
LVDCON
; Select Bank 1
; Disable PLVD interrupt
WRM_UP
BTFSS
GOTO
BANKSEL
BCF
LVDCON,BGST
WRM_UP
PIR1
PIR1,LVDIF
;
;
; Select Bank 0
; Clear PLVD interrupt flag
; Enable PLVD, 4.2-4.4V trip
;**************************************************
;* Test for PLVD trip
BANKSEL
BTFSC
GOTO
8.3
PIR1
PIR1,LVDIF
LO_V_DET
; Select Bank 0
; Test for PLVD trip
; If tripped save 4 pwrfail
Operation During SLEEP
8.4
When enabled, the PLVD circuitry continues to operate
during SLEEP. If the device voltage crosses the trip
point, the LVDIF bit is set and the device awakens from
SLEEP. Device execution continues from the interrupt
vector address, if interrupts have been globally
enabled.
TABLE 8-1:
Address
Effects of a RESET
A device RESET forces all registers to their RESET
state. This forces the PLVD module to be disabled.
8.5
Low Voltage Detect Registers
The registers associated with Programmable Low Voltage Detect are shown in Table 8-1.
SUMMARY OF REGISTERS ASSOCIATED WITH LOW VOLTAGE DETECT
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Value on
all other
RESETS
09Ch
LVDCON
—
—
BGST
LVDEN
LV3
LV2
LV1
LV0
--00 0101
--00 0101
08Ch
PIE1
LVDIE
ADIE
C2IE
C2IE
—
—
—
TMR1IE
0000 ---0
0000 ---0
08Ch
PIR1
LVDIF
ADIF
C2IF
C2IF
—
—
—
TMR1IF
0000 ---0
0000 ---0
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 67
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PIC16C781/782
NOTES:
DS41171B-page 68
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
9.0
ANALOG-TO-DIGITAL
CONVERTER (ADC) MODULE
tures a snapshot of the voltage and holds it for the
ADC. The ADC then generates the 8-bit result via successive approximation.
The 8-bit ADC module, shown in Figure 9-1, has 10
inputs in the PIC16C781/782:
The analog reference voltage (ADCREF) is software
selectable from the following options:
• 8 external channels, AN<7:0> (RA<3:0> and
RB<3:0>)
• 2 internal channels, VR and VDAC
•
•
•
•
The ADC allows conversion of an analog input signal to
a corresponding 8-bit digital value. The desired channel is connected to a Sample-and-Hold by the input
multiplexers. The output of the Sample-and-Hold cap-
FIGURE 9-1:
The analog positive supply: AVDD
The reference input for Comparator C1: VREF1
The Voltage Reference module output: VR
The DAC Converter module output: VDAC
The ADC has the unique feature of being able to operate while the device is in SLEEP mode. To operate in
SLEEP, the ADC conversion clock must be derived
from the ADC’s dedicated internal RC oscillator.
ADC MODULE BLOCK DIAGRAM
VOLTAGE COMPARATOR MODULE
OPA MODULE
0
RA1/AN1/OPA-
1
RA2/AN2/VREF2
2
RA3/AN3/VREF1
3
RB0/INT/AN4/VR
4
RB1/AN5/VDAC
5
RB2/AN6
6
RB3/AN7/OPA
7
CHS<3:0>
AVDD
VREF1
VR
VDAC
VCFG<1:0>
0
1
2
3
Sample
and
Hold
ADCREF
ADC
8
ADRES
4
RA0/AN0/OPA+
ADON
GO/DONE
8
9
DAC MODULE
VR MODULE
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 69
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PIC16C781/782
9.1
Control Registers
9.1.1
ADCON0 REGISTER
The ADC module has three registers. These registers
are:
The ADCON0 register, shown in Register 9-1, controls
the following:
• ADC Result Register:
• ADC Control Register 0:
• ADC Control Register 1:
•
•
•
•
ADRES
ADCON0
ADCON1
The ADCON0 register, shown in Register 9-1, controls
the operations and input channel selection for the ADC
module. The ADCON1 register, shown in Register 9-3,
selects the voltage reference used by the ADC module.
The ADRES register, shown in Register 9-2, holds the
8-bit result of the conversion.
Additional information on using the ADC module can be
found in the PIC Mid-Range MCU Family Reference
Manual (DS33023) and in Application Note AN546
(DS00546).
Clock source and prescaler
Input channel
Conversion start/stop
Enabling of the ADC module
Setting the ADON bit, ADCON0<0>, enables the ADC
module. Clearing ADON disables the module and terminates any conversion in process.
The ADCS<1:0> bits (ADCON0<7:6>) determine the
clock source used by the ADC module.
The CHS<3:0> bits (ADCON0<5:3,1>) determine the
input channel to the ADC module. CHS<3> specifically
determines whether the source is internal or external.
Setting the GO/DONE bit (ADCON0<2>) initiates the
conversion process. The ADC clears this bit at the
completion of the conversion process.
REGISTER 9-1:
ADC CONTROL REGISTER 0 (ADCON0: 1Fh)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/S-0
R/W-0
R/W-0
ADCS1
ADCS0
CHS2
CHS1
CHS0
GO/DONE
CHS3
ADON
bit 7
bit 0
bit 7-6
ADCS<1:0>: ADC Conversion Clock Select bits
00 = FOSC/2
01 = FOSC/8
10 = FOSC/32
11 = ADRC (clock derived from a dedicated RC oscillator)
bit 5-3
CHS<2:0>: Analog Channel Select bits (select which channel to convert)
If CHS3 = 1:
If CHS3 = 0:
000 = channel 0 (AN0)
000 = VR
001 = channel 1 (AN1)
001 = VDAC
010 = channel 2 (AN2)
010 = Reserved. Do not use.
011 = channel 3 (AN3)
011 = Reserved. Do not use.
100 = channel 4 (AN4)
100 = Reserved. Do not use.
101 = channel 5 (AN5)
101 = Reserved. Do not use.
110 = channel 6 (AN6)
110 = Reserved. Do not use.
111 = channel 7 (AN7)
111 = Reserved. Do not use.
bit 2
GO/DONE: ADC Conversion Status bit
1 = ADC conversion cycle in progress. Setting this bit starts an ADC conversion cycle.
0 = ADC conversion is not in progress (this bit is cleared by hardware when conversion is complete)
bit 1
CHS3: Analog Channel Select bit
1 = Internal channel selected for conversion
0 = External channel selected for conversion
bit 0
ADON: ADC On bit
1 = ADC enabled
0 = ADC disabled
Legend:
S = Settable bit
DS41171B-page 70
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
’1’ = Bit is set
’0’ = Bit is cleared
Preliminary
x = Bit is unknown
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PIC16C781/782
9.1.2
ADCON1 REGISTER
9.1.3
The ADCON1 register, shown in Register 9-3, controls
the reference voltage selection for the ADC module.
Bits VCFG<1:0>
(ADCREF).
REGISTER 9-2:
select
the
reference
ADRES REGISTER
The ADRES register, shown in Register 9-2, contains
the 8-bit result of the conversion. At the completion of
the ADC conversion:
voltage
• 8-bit result is loaded into ADRES.
• GO/DONE bit (ADOCN0<2>) is cleared.
• ADC interrupt flag bit ADIF (INTCON<6> and
PIR1<6>) are set.
• If the ADC interrupt is enabled, an interrupt is also
generated.
ADC RESULT REGISTER (ADRES: 1Eh)
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
bit 7
bit 7-0
bit 0
AD<7:0>: ADC Conversion Results bits
Legend:
REGISTER 9-3:
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
ADC CONTROL REGISTER 1 (ADCON1: 9Fh)
U-0
U-0
R/W-0
R/W-0
U-0
U-0
U-0
U-0
—
—
VCFG1
VCFG0
—
—
—
—
bit 7
bit 0
bit 7-6
Unimplemented: Read as ’0’
bit 5-4
VCFG<1:0>: Voltage Reference Configuration bits
00 = AVDD
01 = VREF1
10 = VR
11 = VDAC
bit 3-0
Unimplemented: Read as ’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
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 71
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PIC16C781/782
9.2
Configuring the ADC Module
9.2.1
9.2.2
CONFIGURING ANALOG PORT
PINS
CONFIGURING THE REFERENCE
VOLTAGES
The VCFG<5:4> bits in the ADCON1 register configure
the ADC module reference voltage input, ADCREF. The
reference input can come from any of the following:
The ANSEL and TRISB registers control the operation
of the ADC port pins. The port pins to be used as analog inputs must have their corresponding TRISB bits
set (= 1). The proper ANSEL bits must also be set (analog input) to disable the digital input buffer.
•
•
•
•
Internal voltage reference (VR)
External comparator C1 reference (VREF1)
DAC output (VDAC)
Analog positive supply (AVDD)
If an external reference is chosen for the ADCREF input,
the port pin that multiplexes with the incoming external
reference must also be configured as an analog input.
Note 1: The ADC operation is independent of the
state of the TRISB or ANSEL bits. These
bits must be configured by the firmware
prior to initiation of an ADC conversion.
9.2.3
2: When reading the PORTA or PORTB registers, all pins configured as analog input
channels will read as a ‘0’.
SELECTING THE ADC
CONVERSION CLOCK
The ADC conversion cycle requires 9.5TAD. The source
of the ADC conversion clock is software selectable.
The four possible options for ADC clock are:
3: Analog levels on any pin that is defined as
a digital input, including AN<7:0>, may
cause the input buffer to consume excess
supply current.
•
•
•
•
FOSC/2
FOSC/8
FOSC/32
ADRC (clock derived from a dedicated internal
RC oscillator)
For correct ADC conversion, the ADC conversion clock
(TAD) must be selected to ensure a minimum TAD time
of 1.6 sec. Table 9-1 shows the resultant TAD times
derived from the device operating frequencies and the
ADC clock source selected.
TABLE 9-1:
TAD vs. DEVICE OPERATING FREQUENCIES: PIC16C781/782
ADC Clock Source (TAD)
Operation
ADCS1:ADCS0
Device Frequency
20 MHz
5 MHz
1.25 MHz
333.33kHz
2 TOSC
00
1.6 s
6 s
8 TOSC
01
400 ns
1.6 s
6.4 s
24 s(3)
32 TOSC
10
1.6 s
6.4 s
25.6 s(3)
96 s(3)
RC
11
2 - 6 s(1,4)
2 - 6 s(1,4)
2 - 6 s(1,4)
2 - 6 s(1)
100 ns
(2)
400 ns
(2)
Legend: Shaded cells are outside of recommended range.
Note 1: The RC source has a typical TAD time of 4 s.
2: These values violate the minimum required TAD time.
3: For faster conversion times, the selection of another clock source is recommended.
4: When device frequency is greater than 1 MHz, the RC ADC conversion clock source is recommended for
SLEEP operation only.
DS41171B-page 72
Preliminary
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PIC16C781/782
9.2.4
INITIATING A CONVERSION
The Analog-to-Digital conversion is initiated by setting
the GO/DONE bit in ADCON0 register. When the conversion is complete, the ADC module:
• Clears the GO/DONE bit
• Sets the ADIF flag in the PIR1 register
• Generates an interrupt if the ADIE, PEIE, and GIE
bits are set.
If the conversion must be aborted, the GO/DONE bit
can be cleared in software. The ADRES register will not
be updated with the partially completed ADC conversion sample. Instead, the ADRES will contain the value
from the last completed conversion. After an aborted
conversion, a 2TAD delay is required before another
acquisition/conversion can be initiated. Following the
delay, an input acquisition is automatically started on
the selected channel.
Note:
9.3
2.
CHOLD = 51.2 pF
RS = 10k
1/2 LSb error
RSS = 7k@ VDD = 5V
Note 1: The reference voltage (ADCREF) has no
effect on the equation, since it cancels
itself out.
2: The charge holding capacitor (CHOLD) is
not discharged after each conversion.
3: The maximum recommended impedance
for analog sources is 10k This is
required to meet the pin leakage specification.
The GO/DONE bit should NOT be set in
the same instruction that turns on the ADC.
4: After a conversion has completed, a
1.0TAD delay must be completed before
acquisition can begin again. During this
time the holding capacitor is not connected
to the selected ADC input channel.
ADC Acquisition Requirements
For the ADC module to meet its specified accuracy, the
internal Sample-and-Hold capacitor (CHOLD) must be
allowed to charge to within ½ LSb of the voltage present
on the input channel (see analog input model in Figure
9-2). The analog source resistance (RS) and the internal
sampling switch resistance (RSS) will directly affect the
time required to charge CHOLD. In addition, RSS will vary
over the power supply voltage range (AVDD), and RS will
affect the input offset voltage at the analog input (due to
pin leakage current). Therefore:
1.
Example 9-1 shows the calculation of the minimum
required acquisition time TACQ. This calculation is
based on the following system assumptions.
The maximum recommended impedance for
any analog sources is 10 kOhms.
Following any change in the analog input channel selection, a minimum acquisition delay must
be observed before another conversion can
begin (see Equation 9-1).
To calculate the minimum acquisition time, Equation 9-1
may be used. This equation calculates the acquisition
time to within ½ LSb error, assuming an 8-bit conversion (512 steps for the PIC16C781/782 ADC). The ½
LSb error is the maximum error allowed for the ADC to
meet its specified accuracy.
EQUATION 9-1:
EXAMPLE 9-1:
CALCULATING THE
MINIMUM REQUIRED
ACQUISITION TIME
TACQ = Amplifier Setting Time +
Holding Capacitor Charging Time +
Temperature Coefficient
TACQ = 5 s + TCAP + [(Temp - 25C)(0.05 s/C)]
TCAP
= -CHOLD (RIC + RSS + RS) In(1/511)
-51.2 pF (1 k+ 7k+ 10kIn(0.0020)
-51.2 pF (18 k) In(0.0020)
-0.921 s (-6.2364)
5.747 s
TACQ = 5 s + 5.747 s + [(50C -25C)(0.05s/C)]
10.747 s + 1.25 s
11.997 s
ADC MINIMUM
CHARGING TIME
VHOLD = (ADCREF-(ADCREF/512))•(1-e-TCAP/CHOLD(RIC+Rss+Rs))
Given: VHOLD = (ADCREF/512), for 1/2LSb resolution
The above equation reduces to:
TCAP = -(51.2 pF)(1 k+ RSS + RS) Ln(1/511)
 2001-2013 Microchip Technology Inc.
Preliminary
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PIC16C781/782
FIGURE 9-2:
ANALOG INPUT MODEL
VDD
RS
CPIN
5 pF
VA
Sampling
Switch
VT = 0.6V
ANx
VT = 0.6V
RIC  1k
SS
RSS
CHOLD
= DAC capacitance
= 51.2 pF
ILEAKAGE
± 500 nA
VSS
Legend: CPIN
= input capacitance
VT
= threshold voltage
ILEAKAGE = leakage current at the pin due to
various junctions
RIC
SS
CHOLD
9.4
= interconnect resistance
= sampling switch
= sample/hold capacitance (from DAC)
ADC Configuration and
Conversion
6V
5V
VDD 4V
3V
2V
5 6 7 8 9 10 11
Sampling Switch
( k )
EXAMPLE 9-2:
Example 9-2 demonstrates an ADC conversion. The
RA0/AN0 pin is configured as the analog input. The reference voltage selected is the device AVDD. The ADC
interrupt is enabled, and the ADC conversion clock is
ADRC.
Clearing the GO/DONE bit during a conversion aborts
the current conversion. The ADRES register is NOT
updated with the partially completed ADC conversion
sample. That is, the ADRES register continues to contain the value of the last completed conversion (or the
last value written to the ADRES register). After the ADC
conversion is aborted, a 2TAD wait period is required
before the next acquisition is started. After this 2TAD
wait period, an acquisition is automatically started on
the selected channel.
;********************************************
;* This code block will configure the ADC
;* for polling, AVDD as reference, RC clock
;* and RA0 input.
;*
;* Conversion start & wait for complete
;* polling code included.
;*
BANKSEL
ADCON1
; Select Bank 1
CLRF
ADCON1
; AVDD as VREF
BSF
TRISA,0
; Set RA0 as input
BSF
ANSEL,0
; Set RA0 as analog
BANKSEL
MOVLW
MOVWF
ADCON0
; Select Bank0
B’11000001’
ADCON0
; RC, Ch 0, ADC on
;********************************************
;* Start & Wait for ADC complete, assumes
;* minimum acquisition delay from
;* configuration.
ADC_CNVRT
BANKSEL
BSF
ADC_CN_LOOP
BTFSC
GOTO
MOVF
DS41171B-page 74
ADC CONVERSION
Preliminary
ADCON0
ADCON0,GO
; Select Bank 0
; Start convert
ADCON0,GO ; Test for end
ADC_CN_LOOP ; If not, wait
ADRES,W
; Get result
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PIC16C781/782
9.4.1
9.6
FASTER CONVERSION/LOWER
RESOLUTION TRADE-OFF
Not all applications require a result having 8-bits of resolution. Some may instead, require a faster conversion
time. The ADC module allows users to make a trade-off
of conversion speed for resolution. Regardless of the
resolution required, the acquisition time is the same. To
speed up the conversion, the clock source of the ADC
module may be switched during the conversion, so that
the TAD time violates the minimum specified time (see
the applicable Electrical Specification). Once the switch
is made, all the following ADC result bits are invalid
(see ADC Conversion Timing in the Electrical Specifications section). The clock source may only be
switched between the three oscillator options (it cannot
be switched from/to RC). The equation to determine
the time before the oscillator must be switched for a
desired resolution is as follows:
Conversion time = 2TAD + N • TAD + (8 - N)(2TOSC)
Where: N = number of bits of resolution required.
Since the TAD is based on the device oscillator, the user
must employ some method (such as a timer, software
loop, etc.) to determine when the ADC oscillator must
be changed.
9.5
ADC Operation During SLEEP
The ADC module can operate during SLEEP mode.
This requires that the ADC clock source be set to RC
(ADCS1:ADCS0 = 11). When the RC clock source is
selected, the ADC module waits one instruction cycle
before starting the conversion. This allows the SLEEP
instruction to be executed, which eliminates all digital
switching noise from the conversion. When the conversion is completed the GO/DONE bit is cleared, and the
result is loaded into the ADRES register. If the ADC
interrupt is enabled, the device awakens from SLEEP.
If the ADC interrupt is not enabled, the ADC module is
turned off, although the ADON bit remains set.
When the ADC clock source is another clock option
(not RC), a SLEEP instruction causes the present conversion to be aborted and the ADC module to be turned
off. The ADON bit remains set.
Turning off the ADC places the ADC module in its lowest current consumption state.
Note:
For the ADC module to operate in SLEEP,
the A/D clock source must be set to RC
(ADCS1:ADCS0 = 11). To perform an ADC
conversion in SLEEP, ensure the SLEEP
instruction immediately follows the instruction that sets the GO/DONE bit.
 2001-2013 Microchip Technology Inc.
ADC Accuracy/Error
The absolute accuracy (absolute error) specified for the
ADC converter includes the sum of all contributions for:
•
•
•
•
•
•
Offset error
Gain error
Quantization error
Integral non-linearity error
Differential non-linearity error
Monotonicity
The absolute error is defined as the maximum deviation from an actual transition versus an ideal transition
for any code. The absolute error of the ADC converter
is specified as < ±1 LSb for ADCREF = VDD (over the
device’s specified operating range). However, the
accuracy of the ADC converter degrades as VDD
diverges from VREF.
For a given range of analog inputs, the output digital
code will be the same. This is due to the quantization of
the analog input to a digital code. Quantization error
is typically ± 1/2 LSb and is inherent in the analog to
digital conversion process. The only way to reduce
quantization error is to use an ADC with greater resolution of the ADC converter.
Offset error measures the first actual transition of a
code versus the first ideal transition of a code. Offset
error shifts the entire transfer function. Offset error can
be calibrated out of a system, or introduced into a system, through the interaction of the total leakage current
and source impedance at the analog input.
Gain error measures the maximum deviation of the
last actual transition and the last ideal transition
adjusted for offset error. This error appears as a
change in slope of the transfer function. The difference
in gain error to full scale error is that full scale does not
take offset error into account. Gain error can be calibrated out in software.
Linearity error refers to the uniformity of the code
changes. Linearity errors cannot be calibrated out of
the system. Integral non-linearity error measures the
actual code transition versus the ideal code transition,
adjusted by the gain error for each code. Differential
non-linearity measures the maximum actual code
width versus the ideal code width. This measure is
unadjusted.
If the linearity errors are very large, the ADC may
become non-monotonic. This occurs when the digital
values for one or more input voltages are less than the
value for a lower input voltage.
Preliminary
DS41171B-page 75
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9.6.1
9.9
CLOCK NOISE
In systems where the device frequency is low, use of
the ADC RC clock is preferred. At moderate to high frequencies, TAD should be derived from the device oscillator. TAD must not violate the minimum and should be
 8 s for preferred operation. This is because TAD,
when derived from TOSC, is kept away from on-chip
phase clock transitions. This reduces, to a large extent,
the effects of digital switching noise. This is not possible with the RC derived clock. The loss of accuracy due
to digital switching noise can be significant if many I/O
pins are active.
Transfer Function
The ideal transfer function of the ADC converter is as
follows: the first transition occurs when the analog input
voltage (VAIN) is Analog ADCREF/256 (Figure 9-3).
9.10
References
A good reference for ADC converters is the "AnalogDigital Conversion Handbook" third edition, published
by Prentice Hall (ISBN 0-13-03-2848-0).
FIGURE 9-3:
ADC TRANSFER
FUNCTION
9.7
Effects of a RESET
A device RESET forces all registers to their RESET
state. This forces the ADC module to be turned off, and
any conversion is aborted.
The value that is in the ADRES register is not modified
for a Power-on Reset. The ADRES register contains
unknown data after a Power-on Reset.
Digital Code Output
In systems where the device enters SLEEP mode after
the start of the ADC conversion, the RC clock source
selection is required. In this mode, the digital noise
from the modules in SLEEP is stopped. This method
gives high accuracy.
FFh
FEh
04h
03h
02h
01h
Connection Considerations
Note:
Care must be taken when using the RB2/
AN6 pin in ADC conversions due to its
proximity to the OSC1 pin.
256 LSb
(Full Scale)
255 LSb
4 LSb
3 LSb
2 LSb
00h
If the input voltage exceeds the rail values (VSS or VDD)
by greater than 0.2V, then the accuracy of the conversion is out of specification.
0.5 LSb
1 LSb
9.8
Analog Input Voltage
An external RC filter is sometimes added for antialiasing of the input signal. The R component should be
selected to ensure that the total source impedance is
kept under the 10 k recommended specification. Any
external components connected (via hi-impedance) to
an analog input pin (capacitor, zener diode, etc.) should
have very little leakage current at the pin.
DS41171B-page 76
Preliminary
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FIGURE 9-4:
FLOW CHART OF ADC OPERATION
ADON = 0
Yes
ADON = 0?
No
Acquire
Selected Channel
Yes
GO = 0?
No
ADC Clock
= RC?
Yes
Start of ADC
Conversion Delayed
1 Instruction Cycle
SLEEP Yes
Instruction
?
No
No
Device in
SLEEP?
Finish Conversion
GO = 0
ADIF = 1
Yes
Abort Conversion
GO = 0
ADIF = 0
Wake-up Yes
From
SLEEP?
Finish Conversion
GO = 0
ADIF = 1
No
No
Finish Conversion
GO = 0
ADIF = 1
Wait 2TAD
SLEEP
Power-down A/D
Stay in SLEEP
Power-down ADC
Wait 2TAD
Wait 2TAD
TABLE 9-2:
Address
0Bh
REGISTERS/BITS ASSOCIATED WITH ADC, PIC16C781/782
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR,
BOR
RBIF
Value on
all other
RESETS
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
0000 000x
0000 000u
LVDIE
ADIE
C2IE
C1IE
—
—
—
TMR1IE 0000 ---0
0000 ---0
PIR1
LVDIF
ADIF
C2IF
C1IF
—
—
—
TMR1IF
0000 ---0
ADRES
ADC Result Register
ADCON0
ADCS1 ADCS0
INTCON
8Ch
PIE1
0Ch
1Eh
1Fh
CHS2
CHS1
CHS0
GO/DONE
CHS3
0000 ---0
xxxx xxxx
uuuu uuuu
ADON
0000 0000
0000 0000
9Fh
ADCON1
—
—
VCFG1
VCFG0
—
—
—
—
--00 ----
--00 ----
05h
PORTA
RA7
RA6
RA5
RA4
RA3
RA2
RA1
RA0
xxxx 0000
uuuu 0000
06h
PORTB
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0
xxxx 0000
uuuu 0000
9Dh
ANSEL
1111 1111
1111 1111
Analog Channel Select
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for ADC conversion.
 2001-2013 Microchip Technology Inc.
Preliminary
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PIC16C781/782
NOTES:
DS41171B-page 78
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
10.0
DIGITAL-TO-ANALOG
CONVERTER (DAC) MODULE
10.1
The Digital-to-Analog Converter (DAC) module generates an output voltage proportional to the value in the
8-bit DAC register (see Figure 10-1).
The output of the DAC module can be configured to
drive:
• The reference input to the ADC module
• The reference input to Comparators C1 and C2
• An analog output on pin RB1/AN5/VDAC
The voltage reference input
selected from:
Control Registers
The DAC module is controlled via two special function
registers: DACON0 and DAC. The DACON0 register,
shown in Register 10-1:
• Enables DAC
• Enables output on RB1/AN5/VDAC
• Selects reference voltage
The DAC register, shown in Register 10-2, sets the output of the DAC.
to the DAC can be
• Analog supply AVDD
• Comparator C1 VREF1
• Voltage reference VR
REGISTER 10-1:
DIGITAL-TO-ANALOG CONVERTER CONTROL REGISTER0 (DACON0: 11Fh)
R/W-0
R/W-0
U-0
U-0
U-0
U-0
R/W-0
R/W-0
DAON
DAOE
—
—
—
—
DARS1
DARS0
bit 7
bit 0
bit 7
DAON: Digital-to-Analog Converter Enable bit
1 = DAC enabled
0 = DAC disabled
bit 6
DAOE: Digital-to-Analog Converter Output Enable bit
1 = Output on the VDAC pin
0 = Output is not available for external use
bit 5-2
Unimplemented: Read as ’0’
bit 1-0
DARS<1:0>: Digital-to-Analog Converter Voltage Reference Select bits, DACREF
00 = Analog supply, AVDD
01 = Comparator reference, VREF1 pin
10 = Voltage reference, VR
11 = Reserved, do not use
Legend:
REGISTER 10-2:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
’1’ = Bit is set
’0’ = Bit is cleared
DIGITAL-TO-ANALOG CONVERTER REGISTER (DAC: 11Eh)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
DA7
DA6
DA5
DA4
DA3
DA2
DA1
DA0
bit 7
bit 7-0
x = Bit is unknown
bit 0
DA<7:0>: Digital-to-Analog Converter Digital Input bits
Legend:
R = Readable bit
W = Writable bit
- n = Value at POR
’1’ = Bit is set
 2001-2013 Microchip Technology Inc.
Preliminary
’0’ = Bit is cleared
DS41171B-page 79
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10.2
Control Register
Note 1: To enable the DAC output as a reference
for the ADC module, VCFG<1:0> in
ADCON1 must be set.
The DAC module is enabled by setting the DAON bit
(DACON0<7>).
Bits DARS<1:0> (DACON0<1:0>) determine the voltage reference for the DAC module.
2: To enable the DAC output as a reference
for the Comparator module, C1R/C2R bits
(CM1CON0<2>/CM2CON0<2>) must be
set.
To output the DAC voltage, the DAOE bit
(DACON0<6>) and DAON must be set. To use the
DAC output internally, the appropriate reference select
bits in the destination module must be set.
FIGURE 10-1:
DAC CONVERTER BLOCK DIAGRAM
DAON
DARS<1:0>
AVDD
VREF1
VR
N/C
DS41171B-page 80
DACREF EN
0
1
DAC Register
2
8
DAC
Converter
3
Preliminary
DAOE & DAON
VDAC pin
VDAC
Voltage
for ADC
and
Comparators
Reference
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DAC Configuration
FIGURE 10-2:
DAC TRANSFER
FUNCTION
Example 10-1 shows a sample configuration for the
DAC module. The port pin is configured, AVDD is
selected for the voltage reference, and the DAC output
is enabled.
This code block will configure the DAC
for AVDD Voltage Ref, and RB1/AN5/VDAC as
output.
;
;
;
;
MOVLW
MOVWF
DAC_VALUE
DAC
; Set DAC output
10.4
02h
01h
Select Bank 2
DAC to 00
Enable DAC output
Set REF = VDD
00h
Analog Output Voltage
Effects of RESET
Offset error measures the first actual transition of a
code versus the first ideal transition of a code. Offset
error shifts the entire transfer function. Offset error can
be calibrated out of a system or introduced into a system through the interaction of the output drive capability with the load impedance.
A device RESET forces all registers to their RESET
state. This forces the following conditions:
•
•
•
•
DAC module is off
Reference input to AVDD
Output disabled
DAC register is cleared
10.5
Gain error measures the maximum deviation of the
last actual transition and the last ideal transition
adjusted for offset error. This error appears as a
change in slope of the transfer function. The difference
in gain error to full scale error is that full scale does not
take offset error into account. Gain error can be calibrated out by adjusting the reference voltage.
DAC Module Accuracy/Error
The accuracy/error specified for the DAC includes:
•
•
•
•
•
256 LSb
(full scale)
DACON0
DAC
B’11000000’
DACON0
03h
255 LSb
BANKSEL
CLRF
MOVLW
MOVWF
04h
4 LSb
; Select bank 1
; Set RB1 input
; Set RB1 as analog
2 LSb
BANKSEL TRISB
BSF
TRISB,1
BSF
ANSEL,1
FEh
0.5 LSb
1 LSb
;*
;*
;*
FFh
DAC CONFIGURATION
Digital Code Input
EXAMPLE 10-1:
3 LSb
10.3
Integral non-linearity error
Differential non-linearity error
Gain error
Offset error
Monotonicity
Linearity error refers to the uniformity of the voltage
change with code change. Linearity errors cannot be calibrated out of the system. Integral non-linearity error
measures the actual voltage output versus the ideal voltage output adjusted by the gain error for each code.
Differential non-linearity error measures the maximum actual voltage step versus the ideal voltage step.
This measure is unadjusted.
TABLE 10-1:
Address
REGISTERS/BITS ASSOCIATED WITH DAC
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR,
BOR
Value on
All Other
RESETS
11Fh
DACON0 DAON DAOE
—
—
—
—
DARS1 DARS0 00-- --00 00-- --00
11Eh
DAC
DA7
DA6
DA5
DA4 DA3
DA2
DA1
DA0 0000 0000 0000 0000
86h
TRISB
RB7
RB6
RB5
RB4 RB3
RB2
RB1
RB0 1111 1111 1111 1111
9Dh
ANSEL
AN7
AN6
AN5
AN4 AN3
AN2
AN1
AN0 1111 1111 1111 1111
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for DAC conversion.
 2001-2013 Microchip Technology Inc.
Preliminary
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NOTES:
DS41171B-page 82
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
11.0
OPERATIONAL AMPLIFIER
(OPA) MODULE
11.1.1
The OPA module is enabled by setting the OPAON bit
(OPACON<7>). When enabled, the OPA forces the
output driver of RB3/AN7/OPA into tri-state to prevent
contention between the driver and the OPA output.
The Operational Amplifier (OPA) Module can be configured as either an OPAMP or Voltage Comparator. The
OPA module has the following features:
Clearing the CMPEN bit (OPACON,6>) configures the
module as an OPAMP. Setting CMPEN configures the
module as a voltage comparator.
• External connections to all ports
• Gain Bandwidth Product selectable:
- 70 kHz nom.
- 2 MHz nom.
• Low leakage inputs
• Input Offset Voltage Automatic Calibration Module
(ACM)
• Input Offset Voltage calibration at a programmable common mode voltage using the DAC
• Interrupt-on-change in Comparator mode using
IOCB
11.1
The GBWP bit (OPACON<0>) controls the speed of the
module in both comparator and OPAMP configurations.
Setting GBWP results in a Gain Bandwidth Product
(GBWP) of 2 MHz typical. Clearing GBWP0 results in a
GBWP of the OPA of 70 kHz typical.
Note 1: When the OPA module is enabled, the
RB3/AN7/OPA pin is driven by the
OPAMP output, not by the PORTB driver.
Refer to the Electrical specifications for
the OPAMP output drive capability.
Control Registers
2: In Comparator mode (CMPEN = 1), an
interrupt can be generated using the
IOCB feature of RB3. RB3 must be programmed as a digital input with IOCB
enabled.
The OPACON register, shown in Register 11-1, controls
the OPA module. The CALCON register, shown in
Register 11-2, controls the Automatic Calibration Module.
FIGURE 11-1:
OPACON REGISTER
OPA MODULE BLOCK DIAGRAM
OPAON
CMPEN
GBWP
RA0/AN0/OPA+
OPA
RA1/AN1/OPARB3/AN7/OPA
TO ADC MUX
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Preliminary
DS41171B-page 83
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PIC16C781/782
REGISTER 11-1:
OPAMP CONTROL REGISTER (OPACON: 11Ch)
R/W-0
R/W-0
U-0
U-0
U-0
U-0
U-0
R/W-0
OPAON
CMPEN
—
—
—
—
—
GBWP
bit 7
bit 0
bit 7
OPAON: OPAMP Enable bit
1 = OPAMP is enabled
0 = OPAMP is disabled
bit 6
CMPEN: Comparator Mode Enable bit
1 = Comparator mode
0 = OPAMP mode
bit 5-1
Unimplemented: Read as ’0’
bit 0
GBWP: Gain Bandwidth Product Select bits
1 = 2 MHz typ. (fast mode)
0 = 70 kHz typ. (slow mode)
Legend:
11.1.2
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
CALCON REGISTER
The Automatic Calibration Module (ACM) is an internal
state machine which performs an input offset voltage
calibration (trim) on the OPA module (see Figure 11-2).
Calibration is initiated by setting the CAL bit
(CALCON<7>). Upon completion of the calibration
sequence, the ACM will clear the CAL bit.
Note 1: Auto Calibration must be performed while
the module is configured as an OPAMP
(CMPEN = 0). Performing Auto Calibration function in the Comparator mode
may yield unpredictable results.
If a problem arises in the calibration process, the
CALERR flag (CALCON<6>) will be set to indicate the
failure to calibrate.
Setting CALREF (CALCON<5>) forces calibration at a
common mode voltage specified by the output of the
DAC module. The DAC module must be enabled prior
to calibration. Clearing CALREF will perform the calibration with a common mode voltage of 1.2V. The output pin floats during calibration.
DS41171B-page 84
Preliminary
2: If the internal 1.2V reference is used for
the common mode voltage during Auto
Calibration, CALREF = 0 (CALCON<5>),
a delay for reference stabilization must be
observed before start of calibration.
3: The OPA module shares pins with the
ADC module. Performing ADC conversions on the OPA+ or OPA- pins may
affect OPAMP stability.
4: When using the DAC as a reference for
calibration, CALREF = 1 (CALCON<5>),
the VDAC voltage must be within the specified common mode voltage for the
OPAMP.
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
FIGURE 11-2:
AUTO CALIBRATION MODULE BLOCK DIAGRAM
OPA-
0
1
OPA+
0
1
OPA
0
OPA
1
CALREF
1.2V nominal
0
Automatic Calibration Module
DAC
Module
REGISTER 11-2:
1
CALIBRATION CONTROL REGISTER (CALCON: 110h)
R/S-0
R-0
R/W-0
U-0
U-0
U-0
U-0
U-0
CAL
CALERR
CALREF
—
—
—
—
—
bit 7
bit 0
bit 7
CAL: Start and Status bit
1 = Initiates a calibration
0 = Reserved (CAL is cleared by hardware)
bit 6
CALERR: Calibration Error Indicator bit
1 = Error occurred, OPAMP failed
0 = No error
bit 5
CALREF: Calibration Voltage Select bit
1 = VDAC set to desired common voltage reference
0 = 1.2V nominal source (internal voltage source)
Note:
bit 4-0
VDAC must not exceed OPAMP maximum common mode voltage.
Reserved: Do not use
Legend:
S = Cleared by hardware
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
’1’ = Bit is set
’0’ = Bit is cleared
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 85
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PIC16C781/782
11.2
Configuration as OPAMP or
Comparator
11.3
Effects of RESET
The following example demonstrates calibration of the
OPA module as an Operational Amplifier.
A device RESET forces all registers to their RESET
state. This disables the OPA module and clears any
calibration.
EXAMPLE 11-1:
11.4
;*
;*
;*
;*
;*
CALIBRATION FOR
OPAMP MODE
This code block will configure the OPA
module as an Op Amp, 2 MHz GBWP, and
calibrated for a common mode voltage of
1.2V. Routine returns w=0 if
calibration good.
BANKSEL
MOVLW
MOVWF
OPACON
B’10000001’
OPACON
BCF
BSF
CALCON,CALREF; Set 1.2V
CALCON,CAL
; Start
CAL_LOOP
BTFSC
GOTO
MOVLW
BTFSS
CLRW
RETURN
; Select Bank 2
; Op Amp mode &
; 2 MHz GBWP
CALCON,CAL
;
CAL_LOOP
;
ERROR_FLAG
CALCON,CALERR;
;
Test for end
If not, wait
Test for error
If no, return 0
The following example demonstrates how to configure
and calibrate the OPA module as a Voltage Comparator.
EXAMPLE 11-2:
;*
;*
;*
;*
;*
CALIBRATION FOR
COMPARATOR MODE
This code block will configure the OPA
module as a voltage comparator, slow
speed, and calibrated for a common mode
voltage of 2.5 V (assumes VDD=5V).
Routine returns w=0 if calibration good.
BANKSEL
MOVLW
MOVWF
OPACON
B’10000000’
OPACON
; Select Bank 2
BSF
; Op Amp mode,
; slow
CALCON,CALREF; Common mode=DAC
MOVLW
MOVWF
MOVLW
MOVWF
H’0x80’
DAC
B’10000000’
DACON0
BSF
CAL_LOOP
BTFSC
GOTO
MOVLW
BTFSS
CLRW
BSF
RETURN
DS41171B-page 86
OPA Module Performance
Common AC and DC performance specifications for
the OPA module:
•
•
•
•
•
Common Mode Voltage Range
Leakage Current
Input Offset Voltage
Open Loop Gain
Gain Bandwidth Product
Common mode voltage range is the specified voltage
range for the OPA+ and OPA- inputs, for which the OPA
module will perform to within its specifications. The
OPA module is designed to operate with input voltages
between 0 and VDD-1.4V. Behavior for Common mode
voltages greater than VDD-1.4V, or below 0V, are not
guaranteed.
Leakage current is a measure of the small source or
sink currents on the OPA+ and OPA- inputs. To minimize the effect of leakage currents, the effective impedances connected to the OPA+ and OPA- inputs should
be kept as small as possible and equal.
Input offset voltage is a measure of the voltage difference between the OPA+ and OPA- inputs in a closed
loop circuit with the OPA in its linear region. The offset
voltage will appear as a DC offset in the output equal to
the input offset voltage, multiplied by the gain of the circuit. The input offset voltage is also affected by the
Common mode voltage. The OPA has an automatic
calibration module which can minimize the input offset
voltage of the module.
Open loop gain is the ratio of the output voltage to the
differential input voltage, (OPA+) - (OPA-). The gain is
greatest at DC and falls off with frequency.
Gain Bandwidth Product or GBWP is the frequency
at which the open loop gain falls off to 0 dB. The lower
GBWP is optimized for systems requiring low frequency response and low power consumption.
; DAC at VDD/2
CALCON,CAL
; enable DAC,
; VDD ref
; Start
CALCON,CAL
CAL_LOOP
; Test for end
; If not, wait
ERROR_FLAG
CALCON,CALERR; Test for error
; If no, return 0
OPACON,CMPEN ; Comparator mode
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
TABLE 11-1:
Address
REGISTERS ASSOCIATED WITH THE OPA MODULE
Name
Bit 7
Bit 6
Bit 5
CMPEN
—
Bit 4 Bit 3 Bit 2
11Ch
OPACON
OPAON
110h
CALCON
CAL
9Dh
ANSEL
AN7
86h
TRISB
PORTB Data Direction Register
85h
TRISA
PORTA Data Direction Register
11Eh
DAC
11Fh
DACON0
CALERR CALREF
AN6
AN5
Bit 1
Bit 0
Value on:
POR, BOR
Value on
all other
RESETS
—
—
—
—
—
—
—
—
—
000- ---- 000- ----
AN1
AN0
1111 1111 1111 1111
AN4
AN3 AN2
GBWP 00-- ---0 00-- ---0
1111 1111 1111 1111
1111 1111 1111 1111
DA7
DA6
DA5
DA4
DAON
DAOE
—
—
DA3 DA1
—
—
DA1
DA0
0000 0000 0000 0000
DARS1 DARS0 00-- --00 00-- --00
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for the OPA module.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 87
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PIC16C781/782
NOTES:
DS41171B-page 88
Preliminary
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12.0
COMPARATOR MODULE
The comparator module has two separate voltage comparators: Comparator C1 and Comparator C2 (see
Figure 12-1).
Each comparator offers the following list of features:
•
•
•
•
•
•
•
•
•
•
Control and configuration register
Comparator output available externally
Programmable output polarity
Interrupt-on-change flags
Wake-up from SLEEP
Configurable as feedback input to the PSMC
Programmable four input multiplexer
Programmable reference selections
Programmable speed
Output synchronization to Timer1 clock input
(Comparator C2 only)
12.1
TABLE 12-1:
Control Registers
COMPARATOR C1 CONTROL
REGISTER
The CM1CON0 register (shown in Register 12-1) contains the control and status bits for the following:
•
•
•
•
•
The output of the comparator is available internally via
the C1OUT flag (CM1CON0<6>). To make the output
available for an external connection, the C1OE flag
(CM1CON0<5>) must be set. If the module is disabled
with C1OE set, the output will be driven as shown in
Table 12-2:
The polarity of the comparator output can be inverted
by setting the C1POL flag (CM1CON0<4>). Clearing
C1POL results in a non-inverted output. A complete
table showing the output state versus input conditions
and the polarity bit is shown in Table 12-2.
Both comparators have separate control and configuration registers: CM1CON0 for C1 and CM2CON0 for C2.
In addition, Comparator C2 has a second control register, CM2CON1, for synchronization control and simultaneous reading of both comparator outputs.
12.1.1
Setting C1R (CM1CON0<2>) selects the output of the
DAC module as the reference voltage for the comparator. Clearing C1R selects the VREF1 input on the RA3/
AN3/VREF1 pin.
Input Condition
C1POL
C1OUT
C1VN > C1VP
0
0
C1VN < C1VP
0
1
C1VN > C1VP
1
1
C1VN < C1VP
1
0
Note 1: The internal output of the comparator is
latched at the end of each instruction
cycle. External outputs are not latched.
2: The C1 interrupt will operate correctly
with C1OE set or cleared.
Comparator enable
Comparator input selection
Comparator reference selection
Output mode
Comparator speed
3: For the output of C1 on RB6/C1/
PSMC1A, the PSMC must be disabled
and TRISB<6> must be ‘0’.
Setting C1ON (CM1CON0<7>) enables Comparator
C1 for operation.
Bits C1CH<1:0> (CM1CON0<1:0>) select the comparator input from the four analog pins AN<7:4>.
Note:
OUTPUT STATE VERSUS
INPUT CONDITIONS
C1SP (CM1CON0<3>) configures the speed of the
comparator. When C1SP is set, the comparator operates at its normal speed. Clearing C1SP operates the
comparator in a slower, low power mode.
To use AN<7:4> as analog inputs, the
appropriate bits must be programmed in
the ANSEL register.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 89
PIC16C781.book Page 90 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
FIGURE 12-1:
COMPARATOR C1 SIMPLIFIED BLOCK DIAGRAM
C1CH<1:0>
2
RB0/INT/AN4/VR
To Interrupt and
PSMC Logic
C1ON
0
RB1/AN5/VDAC
1
C1VP
RB2/AN6
C1OE
C1SP
C1VN
RB6/C1/PSMC1A
C1OUT
C1
2
RB3/AN7/OPA
C1POL
3
C1R
RA3/AN3/VREF1
0
VDAC
FIGURE 12-2:
1
COMPARATOR C2 SIMPLIFIED BLOCK DIAGRAM
C2CH<1:0>
2
RB0/INT/AN4/VR
0
To Interrupt and
PSMC Logic
C2ON
C2SYNC
C2SP
RB1/AN5/VDAC
C2VN
1
C2VP
RB2/AN6
C2OUT
C2
2
C2POL
3
C2R
0
VDAC
DS41171B-page 90
RB7/C2/PSMC1B/T1G
1
RB3/AN7/OPA
RA2/AN2/VREF2
0
C2OE
D
From TMR1
Clock
Q
Q
1
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
REGISTER 12-1:
COMPARATOR C1 CONTROL REGISTER0 (CM1CON0: 119h)
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
bit 7
C1ON: Comparator C1 Enable bit
1 = C1 Comparator is enabled
0 = C1 Comparator is disabled
bit 6
C1OUT: Comparator C1 Output bit
If C1POL = 1 (inverted polarity):
C1OUT = 1, C1VP < C1VN
C1OUT = 0, C1VP > C1VN
If C1POL = 0 (non-inverted polarity):
C1OUT = 1, C1VP > C1VN
C1OUT = 0, C1VP < C1VN
bit 5
C1OE: Comparator C1 Output Enable bit
1 = C1OUT is present on the RB6/C1/PSMC1A 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 Select bit
1 = C1 operates in normal speed mode
0 = C1 operates in low power, slow speed mode
bit 2
C1R: Comparator C1 Reference Select bits (non-inverting input)
1 = C1VP connects to VDAC output
0 = C1VP connects to VREF1
bit 1-0
C1CH<1:0>: Comparator C1 Channel Select bits
00 = C1VN of C1 connects to AN4
01 = C1VN of C1 connects to AN5
10 = C1VN of C1 connects to AN6
11 = C1VN of C1 connects to AN7
Note 1: C1OUT will only drive RB6/C1/PSMC1A if:
(C2OE = 1) & (C2ON = 1) & (TRISB<7> = 0) & ((SMCON = 0)
or ((SMCOM = 0) & (SCEN = 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
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 91
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12.1.2
COMPARATOR C2 CONTROL
REGISTERS
The CM2CON0 register is a functional copy of the
CM1CON0 register described in Section 12.1.1. A second control register, CM2CON1, is also present for
control of an additional synchronizing feature, as well
as mirrors of both comparator outputs.
12.1.2.1
The output of the comparator is available internally via
the C2OUT bit (CM2CON0<6>). To make the output
available for an external connection, the C2OE bit
(CM2CON0<5>) must be set.
Note 1: The internal output of the comparator is
latched at the end of each instruction
cycle. External outputs are not latched.
2: The C2 interrupt will operate correctly
with C2OE set or cleared. An external
output is not required for the C2 interrupt.
Control Register CM2CON0
The CM2CON0 register, shown in Register 12-2, contains the control and status bits for Comparator C2.
3: For C2 output on RB7/C2/PSMC1B/T1G:
(C2OE=1) & (C2ON=1) & (TRISB<7>=0)
& ((SMCON=0) or ((SMCOM=0) &
(SCEN=0))).
Setting C2ON (CM2CON0<7>) enables Comparator
C2 for operation.
Bits C2CH<1:0> (CM2CON0<1:0>) select the comparator input from the four analog pins, AN<7:4>.
Note 1: To use AN<7:4> as analog inputs, the
appropriate bits must be programmed in
the ANSEL register.
C2R (CM2CON0<2>) selects the reference to be used
with the comparator. Setting C2R (CM2CON0<2>)
selects the output of the DAC module as the reference
for the comparator. Clearing C2R selects the VREF2
input on the RA2/AN2/VREF2 pin.
DS41171B-page 92
The comparator output, C2OUT, can be inverted by
setting the C2POL bit (CM2CON0<4>). Clearing
C2POL results in a non-inverted output. A complete
table showing the output state versus input conditions
and the polarity bit is shown in Table 12-3.
C2SP (CM2CON0<3>) configures the speed of the
comparator. When C2SP is set, the comparator operates at its normal speed. Clearing C2SP operates the
comparator in low power mode.
Preliminary
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REGISTER 12-2:
COMPARATOR C2 CONTROL REGISTER0 (CM2CON0: 11Ah)
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
bit 7
C2ON: Comparator C2 Enable bit
1 = C2 Comparator is enabled
0 = C2 Comparator is disabled
bit 6
C2OUT: Comparator C2 Output bit
If C2POL = 1 (inverted polarity):
C2OUT = 1, C2VP < C2VN
C2OUT = 0, C2VP > C2VN
If C2POL = 0 (non-inverted polarity):
C2OUT = 1, C2VP > C2VN
C2OUT = 0, C2VP < C2VN
bit 5
C2OE: Comparator C2 Output Enable bit
1 = C2OUT is present on RB7/C2/PSMC1B/T1G(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 Select bit
1 = C2 operates in normal speed mode
0 = C2 operates in low power, slow speed mode.
bit 2
C2R: Comparator C2 Reference Select bits (non-inverting input)
1 = C2VP connects to VDAC
0 = C2VP connects to VREF2
bit 1-0
C2CH<1:0>: Comparator C2 Channel Select bits
00 = C2VN of C2 connects to AN4
01 = C2VN of C2 connects to AN5
10 = C2VN of C2 connects to AN6
11 = C2VN of C2 connects to AN7
Note 1: C2OUT will only drive RB7/C2/PSMC1B/T1G if:
(C2OE = 1) & (C2ON = 1) & (TRISB<7> = 0) & ((SMCON = 0) or
((SMCOM = 0) & (SCEN = 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
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 93
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PIC16C781/782
12.1.2.2
Control Register CM2CON1
Comparator C2 has one additional feature: its output
can be synchronized to the Timer1 clock input. Setting
C2SYNC (CM2CON1<0>) synchronizes the output of
Comparator 2 to the falling edge of Timer 1’s clock input
(see Figure 12-1 and Register 12-3).
REGISTER 12-3:
The CM2CON1 register also contains mirror copies of
both comparator outputs, MC1OUT and MC2OUT
(CM2CON1<7:6>). The ability to read both outputs
simultaneously from a single register eliminates the
timing skew of reading separate registers.
COMPARATOR C2 CONTROL REGISTER1 (CM2CON1: 11Bh)
R-0
R-0
MC1OUT MC2OUT
U-0
U-0
U-0
U-0
U-0
R/W-0
—
—
—
—
—
C2SYNC
bit 7
bit 0
bit 7
MC1OUT: Mirror Copy of C1OUT (CM1CON0<6>)
bit 6
MC2OUT: Mirror Copy of C2OUT (CM2CON0<6>)
bit 5-1
Unimplemented: Read as ’0’
bit 0
C2SYNC: C2 Output Synchronous Mode bit
1 = C2 output is synchronous to falling edge of TMR1 clock
0 = C2 output is asynchronous
Legend:
DS41171B-page 94
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
’1’ = Bit is set
’0’ = Bit is cleared
Preliminary
x = Bit is unknown
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12.2
Comparator Configuration
12.2.1
The following examples show the use of the Comparator module in:
• A simple voltage comparator configuration synchronized to the Timer 1 clock input.
• A comparator input to the PSMC with a programmable DAC reference.
• A low power window comparator configuration
with interrupt-on-change.
FIGURE 12-3:
EXAMPLE: C2 SYNCHRONIZED TO
T1CKI
In this example, Comparator C2 is configured as a normal voltage comparator synchronized to the T1CKI
input. A block diagram of the comparator with external
connections is shown in Figure 12-2.
COMPARATOR C2 CONFIGURATION WITH OUTPUT SYNCHRONIZED TO T1CKI
PIC16C78X
C2POL
RB2/AN6
-
INPUT
D
C2
+
RA2/AN2/VREF2
CK
Q
CM2CON0<6>
Q
External Reference
RA6/OSC2/CLKOUT/T1CKI
External Oscillator
EXAMPLE 12-1:
;*
;*
;*
;*
;*
12.2.2
C2 CONFIGURATION
PROGRAM
This code block will configure C2
for normal speed and output polarity,
input on AN6, Reference from VREF2, and
output synchronization to TMR1 clock.
BANKSEL
BSF
BSF
BSF
TRISA
TRISA,RA2
TRISA,RA6
TRISB,RB2
;
;
;
;
BSF
BSF
ANSEL,AN2
ANSEL,AN6
; AN2 as analog
; AN6 as analog
BANKSEL CM2CON0
MOVLW
B’10001010’
MOVWF
CM2CON0
BSF
Select
RA2 as
RA6 as
RB2 as
Bank 1
input
input
input
EXAMPLE: C1 INPUT TO PSMC W/
DAC AS REFERENCE
In this example, Comparator C1 is configured as a noninverting normal speed voltage comparator input to the
PSMC, with a programmable reference voltage. A
block diagram of the comparator with external connections is shown in Figure 12-3.
; Select Bank 2
; Set C2; no out
; VREF2, AN6
CM2CON1,C2SYNC ; CLK sync
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 95
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PIC16C781/782
FIGURE 12-4:
CONFIGURATION OF COMPARATOR C1 WITH DAC
PIC16C78X
C1POL = 0
RB3/AN7/OPA
C1OUT
-
INPUT
C1
PSMC
+
VDAC
EXAMPLE 12-2:
;*
;*
;*
DAC
PROGRAMMING C1 FOR
PSMC FEEDBACK
12.2.3
To form a low power window comparator, Comparators
C1 & C2 are configured as follows:
This code block will configure Comparator
C1 for normal speed and output polarity,
input on AN7, and Reference from the DAC
BANKSEL
BSF
BSF
TRISA
TRISB,RB3
ANSEL,AN7
BANKSEL
CLRF
MOVLW
MOVWF
MOVLW
MOVWF
DACON0
;
DAC
;
B’10000000’ ;
DACON0
;
DAC_VALUE
DAC
;
MOVLW
MOVWF
B’10001111’ ; C1; no out,
CM1CON0
; VREF1, AN7
FIGURE 12-5:
EXAMPLE: LOW POWER WINDOW
COMPARATOR WITH INTERRUPT
• Common input RB0/INT/AN4/VREF
• Separate external reference voltages
• Programmed for slow speed operation
; Select Bank 1
; RB3 as input
; Set RB3 as analog
In addition, the output of comparator C2 must be
inverted for common polarity with C1.
Select Bank 2
DAC=00h
Enable, no out
DACREF = VDD
A block diagram of the window comparator with external connections is shown in Figure 12-4.
Trip Level
WINDOW COMPARATOR WITH INTERRUPT
PIC16C78X
INPUT
AN4
C2
CM2CON1<6>
+
CLPOL=1
VREF2
VOLTAGE REFERENCE
C1
VREF1
+
CM2CON1<7>
CLPOL=0
DS41171B-page 96
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
EXAMPLE 12-3:
;*
;*
;*
;*
;*
;*
;*
;*
WINDOW COMPARATOR
Example of Low Power Window Comparator C1
This code block will configure Comparator
C1 and C2 for slow speed, C1 non invert,
C2 invert, input on AN4, and external
References
Interrupt service routine included
BANKSEL
BSF
BSF
BSF
TRISA
TRISA,2
TRISA,3
TRISB,0
;
;
;
;
Select Bank 1
RA2 input
RA3 input
Set RB0
BSF
BSF
BSF
ANSEL,AN2
ANSEL,AN3
ANSEL,AN4
; RA2 analog
; RA3 analog
; RB4 analog
BANKSEL
MOVLW
MOVWF
MOVLW
MOVWF
CM1CON0
;
B’10000000’ ;
CM1CON0
;
B’10010000’ ;
CM2CON0
;
Select Bank 2
C1: no output
VREF1, AN4
C2: no output
invert,VREF1,AN4
BANKSEL
PIE1
; Select Bank 1
BCF
INTCON,GIE ; Disable Int
BSF
PIE1,C1IE ; Enabl C1&C2 Ints
BSF
PIE1,C2IE
BSF
INTCON,PEIE
BSF
INTCON,GIE ; Enabl Global Ints
;********************************************
;* WINDOW COMPARATOR ISR with context save
WC_INT_SRV_R
MOVWF
SWAPF
MOVWF
BANKSEL
MOVLW
ANDWF
MOVWF
W_SAVE
; Save W & STATUS
STATUS,W
STATUS_SAV
PIR1
; Select Bank 0
B’00110000’ ; Save Int
PIR1,W
WIN_INT
;*** CLEAR C1 INTERRUPT
BTFSS
GOTO
BANKSEL
MOVF
BANKSEL
BCF
WIN_INT,C1IF; C1 Int ?
TST_C2_INT
CM1CON0
; Select Bank 2
CM1CON0,F ; Clear C2 mismatch
PIR1
; Select Bank 0
PIR1,C1IF ; Clear C2 Int
;*** CLEAR C2 INTERRUPT
TXT_C2_INT
BTFSS
GOTO
BANKSEL
MOVF
BANKSEL
BCF
WIN_INT,C2IF; C2 int?
USER_ISR
CM2CON0
; Select Bank 2
CM2CON0,F ; Clear C2 mismatch
PIR1
; Select Bank 0
PIR1,C1IF ; Clear C2 int
USER_ISR
;*** USER INTERRUPT ROUTING
;*
SWAPF
MOVWF
SWAPF
SWAPF
RETFIE
STATUS_SAVE,W; Restore W &
; STATUS
STATUS
W_SAVE,F
W_SAVE,W
; Return
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 97
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PIC16C781/782
12.3
Effects of RESET
A RESET forces all registers to their RESET state. This
disables both comparators.
TABLE 12-2:
Address
REGISTERS ASSOCIATED WITH THE COMPARATOR MODULE
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Value on
all other
RESETS
C1OUT
C1OE C1POL C1SP
C1R
C1CH1
C1CH0
0000 0000
0000 0000
C2OUT
C2OE C2POL C2SP
C2R
C2CH1
C2CH0
0000 0000
0000 0000
—
—
C2SYNC
00-- ---0
00-- ---0
PORTA Data Direction Register
1111 1111
1111 1111
PORTB Data Direction Register
1111 1111
1111 1111
Name
Bit 7
Bit 6
119h
CM1CON0
C1ON
11Ah
CM2CON0
C2ON
11Bh
CM2CON1 MC1OUT MC2OUT
85h
TRISA
86h
TRISB
05h
PORTA
RA7
RA6
Bit 5
—
RA5
Bit 4
—
—
RA4
RA3
RA2
RA1
RA0
xxxx 0000
uuuu 0000
uuuu 0000
06h
PORTB
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0
xxxx 0000
9Dh
ANSEL
AN7
AN6
AN5
AN4
AN3
AN2
AN1
AN0
1111 1111
1111 1111
0Ch
PIR1
LVDIF
ADIF
C2IF
C1IF
—
—
—
TMR1ON
0000 ---0
0000 ---0
8Ch
PIE1
LVDIE
ADIE
C2IE
C1IE
—
—
—
TMR1IE
0000 ---0
0000 ---0
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for comparator.
DS41171B-page 98
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
13.0
PROGRAMMABLE SWITCH
MODE CONTROLLER (PSMC)
The Programmable Switch Mode Controller module
provides all the necessary features to implement a
pulsed feedback control system. The PSMC generates
a pulse output based on its analog feedback.
Feedback from the comparator is programmable,
allowing:
• Single or dual channel feedback
• Programmable reference voltage selection
• Programmable polarity
The pulse output of the PSMC is also programmable,
featuring either Pulse Width (PWM) or Pulse Skip
(PSM) Modulation. In PSM, a fixed duty cycle is generated or skipped, based on feedback. In PWM a feedback controlled pulse width is generated. In addition,
the output configuration of the PSMC is programmable,
enabling the following features:
All pulse start and duty cycle limit timing features of the
PSMC are derived from the internal CPU clock.
Block diagrams for the PSMC are shown in Figure 13-1
through Figure 13-3.
13.1
Pulse Width Modulation (PWM)
In the PWM mode, the PSMC (shown in Figure 13-1
and Figure 13-2) is a timer-driven set/RESET pulse
generator. Pulses are initiated by the internal counter
chain. Following the completion of the programmable
minimum duty cycle, the output pulse is terminated by
either a high to low transition on the comparator output,
or by the programmable maximum duty cycle (see
Table 13-1 and Table 13-2). The resulting output is a
variable duty cycle pulse with:
•
•
•
•
Programmable frequency
Feedback specified duty cycle
Programmable minimum duty cycle including 0%
Programmable maximum duty cycle
• A single output
• A single output plus a slope compensation output
• Dual alternating outputs
FIGURE 13-1:
PSMC MODULE IN SINGLE OUTPUT PWM MODE (SIMPLIFIED BLOCK
DIAGRAM)
EXAMPLE
Min DC
Period
New Cycle
FOSC
1:1
SMCCL1
3
S1
1:2
1:4 1:8
Max D/C
SC Switch
2
1
C1OUT
0
RB6/C1/
PSMC1A
RB7/C2/
PSMC1B/T1G
S0
SMCCL0
PSMC
CLK
HIGH IMPEDANCE
ASSUMES
4-bit Counter
S1APOL
New
Cycle
S
2
RB6/C1/PSMC1A
Q
Set
Dominant
R
2
PSMC Max
Controller DC
MINDC<1:0>
HIGH IMPEDANCE
SCEN=1
PWM/PSM=1
SMCON=1 SMCOM=0
DC = Duty Cycle
4
MAXDC<1:0>
S1APOL=0
SMCCS=0
SC
Switch
VDD
C1POL
RB7/C2/PSMC1B/T1G
C1OUT
C1
C2POL
SMCCS
SCEN
N
C2OUT
C2
Comparator Module
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 99
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PIC16C781/782
FIGURE 13-2:
PSMC MODULE IN DUAL ALTERNATING OUTPUT PWM MODE (SIMPLIFIED
BLOCK DIAGRAM)
EXAMPLE
Min DC
Min DC
Min DC
Period
Period
New Cycle A
FOSC
1:1
1:2
1:4
1:8
3
S1
2
1
0
New Cycle B
Max DC
SMCCL1
SMCCL0
C1OUT
RB6/C1/
PSMC1A
RB7/C2/
PSMC1B/T1G
S0
PSMC
CLK
ASSUMES
4-bit Counter
S1APOL=0
S1BPOL=0
DC = Duty Cycle
4
MAXDC<1:0>
MINDC<1:0>
SMCCS=0 PWM/PSM=1
SMCON=1 SMCOM=1
S1APOL
2
New
Cycle A
PSMC
Controller New
Cycle B
2
Max
DC
S
RB6/C1/PSMC1A
Q
Set
Dominant
R
C1POL
S1BPOL
RB7/C2/PSMC1B/T1G
C1OUT
C1
S
Set
Dominant
R
SMCCS
C2POL
Q
C2OUT
C2
Comparator Module
TABLE 13-1:
PSMC1A OUTPUT SEQUENCE IN PWM MODE USING C1 COMPARATOR ONLY
Time
MINDC<1:0>
C1OUT
PSMC1A Output Signal
00
H
L
x
x
HL
LH
x
01
0
01
1
q 0
0
q 0
Beginning of PWM cycle
During Min Duty Cycle
After Min Duty Cycle, Before
Max Duty Cycle
non-zero
non-zero
x
Max Duty Cycle
Legend: x = Don’t Care
DS41171B-page 100
x
q = Prior State
0 = Inactive
1 = Active
Preliminary
H = High
L = Low
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PIC16C781/782
TABLE 13-2:
PSMC1A OUTPUT SEQUENCE IN PWM MODE USING C1 AND C2 COMPARATORS
Time
MINDC<1:0>
C1OUT
C2OUT
PSMC1A Output Signal
00
H
L
x
x
x
HL
LH
H
x
x
H
x
L
x
x
H
x
HL
LH
x
01
0
0
01
1
q0
0
q0
0
q0
Beginning of PWM cycle
non-zero
non-zero
x
During Min Duty Cycle
After Min Duty Cycle,
Before Max Duty Cycle
Max Duty Cycle
Legend: x = Don’t Care
x
q = Prior State
 2001-2013 Microchip Technology Inc.
0 = Inactive
1 = Active
Preliminary
H = High
L = Low
DS41171B-page 101
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PIC16C781/782
13.1.1
PULSE SKIP MODULATION (PSM)
cycle. If the comparator output = L, no pulse is initiated
and the PSMC waits for the start of the next pulse (see
Table 13-3 and Table 13-4). In this mode, both the frequency and duty cycle of the output pulse are programmable. The analog feedback gates the presence or
absence of the pulse on a pulse-by-pulse basis.
In PSM (Pulse Skip Modulation), the PSMC operates
as a fixed duty cycle pulse generator, with its output
gated by the analog feedback (see Figure 13-3). Immediately prior to the initiation of a pulse, the analog feedback is sampled. If the comparator output = H, a pulse
is initiated and held active for the programmed duty
FIGURE 13-3:
PSMC MODULE IN SINGLE OUTPUT PSM MODE (SIMPLIFIED BLOCK
DIAGRAM)
EXAMPLE
Period
New Cycle
FOSC
:1
:2
:4
Programmed DC
:8
Select DC
15/16 Period
SC Switch
3
S1
SMCCL1
SMCCL0
2
1
C1OUT
RB6/C1/
PSMC1A
RB7/C2/
PSMC1B/T1G
0
S0
PSMC
CLK
HIGH IMPEDANCE
ASSUMES
4-bit Counter
DC = Duty Cycle
4
S1APOL=0
SMCCS=0
S1APOL
New
Cycle
DC<1:0>
S
HIGH IMPEDANCE
SCEN=1
PWM/PSM=0
SMCON=1 SMCOM=0
RB6/C1/PSMC1A
Q
Set
Dominant
R
2
PSMC Max
Controller DC
SC
Switch
VDD
C1POL
C1OUT
RB7/C2/PSMC1B/T1G
C1
SMCCS
C2POL
N
SCEN
C2OUT
C2
Comparator Module
TABLE 13-3:
PSMC1A OPERATION IN PSM MODE USING C1 COMPARATOR ONLY
Time
Beginning of PSM cycle
During Pulse
End of Pulse
Legend: x = Don’t Care
DS41171B-page 102
C1OUT
PSMC1A Output Signal
H
L
x
01
0
No Change
1
10
x
0 = Inactive
1 = Active
H = High
Preliminary
L = Low
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
TABLE 13-4:
PSMC1A OUTPUT SEQUENCE IN PSM MODE USING C1 AND C2 COMPARATORS
Time
C1OUT
C2OUT
PSMC1A Output Signal
H
L
x
x
x
x
H
x
L
x
x
x
01
0
0
No Change
No Change
10
1 = Active
H = High
Beginning of PSM cycle
During Pulse Duty Cycle
After Pulse Duty Cycle
Legend: x = Don’t Care
13.1.2
0 = Inactive
SINGLE OR DUAL OUTPUT
13.1.3
The PSMC has the capability to operate with either a
single output, or dual alternating outputs. In the single
output mode, the PSMC generates an output pulse on
PSMC1A output only. The pulses are at the programmed frequency, and are variable between the programmed minimum and maximum duty cycle limits. In
the dual output mode, the PSMC generates output
pulses which alternate between PSMC1A and
PSMC1B. The pulses generated at each output are
generated at one half of the programmed frequency,
and between 50% of the programmed minimum. and
50% maximum of the output duty cycle. The maximum
duty cycle for either output is 50%.
FIGURE 13-4:
L = Low
SLOPE COMPENSATION
An optional feature of the PSMC single output mode is
the ability to configure the PSMC1B output for use as a
slope compensation ramp generator. In this mode, the
PSMC1B output is pulled low for the last 1/16 of each
pulse cycle. Connecting the PSMC1B output to an RC
network, similar to Figure 13-4, results in a positive
going pseudo ramp function. This pseudo ramp function is useful as an offset function for the loop error signal in unstable conditions at a duty cycle of greater than
50%.
Note:
When the Slope Compensation switch is
enabled (SMCOM = 0, and SCEN = 1), the
S1BPOL bit has no effect (see RC Network
on next page for more detail).
SLOPE COMPENSATION (SC) SWITCH OPERATION
t = 15/16T
t=0
VDD
PWM Signal
on PSMC1A
pin
PSMC1A
PIC16C78X
VDD
PSMC
Module
R
DC = duty cycle
PSMC1B
T = Period
150
- On
C
SC Switch
SC Switch
on PSMC1B
pin
- Off
VSS
VSS
To Slope
Compensation
Circuit
Voltage across C
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 103
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PIC16C781/782
13.2
Control Registers
In the PWM mode, the MAXDC <1:0> bits
(PSMCCON0 <3:2>) specify the maximum duty cycle
limit.
The PSMC is controlled by means of two special function registers: PSMCCON0 and PSMCCON1.
In
the
PSM
mode,
the
DC<1:0>
bits
(PSMCCON0<1:0>) specify the fixed duty cycle.
The PSMCCON0 register (Register 13-1) contains
control bits for:
• Frequency of the output pulse
• Minimum and maximum duty cycle in PWM mode
• Fixed duty cycle in PSM mode
13.2.2
The PSMCCON1 register (Register 13-2) contains the
control bits for:
The PWM/PSM bit (PSMCCON1<1>) configures the
output mode of the PSMC. When the PWM/PSM bit is
set, the PSMC is configured for a PWM output. When
the PWM/PSM bit is cleared, a fixed duty cycle pulse is
output.
To enable the PSMC operation, the SMCON bit in the
PSMCCON1 register must be set (see Register 13-2).
• Enabling the PSMC module
• Setting the PSMC mode
• Configuring inputs and outputs
Note:
13.2.1
The SMCCS bit (PSMCCON1<0>) sets the input
mode. When the SMCCS bit is set, the PSMC is configured for two inputs: C1 and C2. When cleared, only
Comparator C1 is used.
Following RESET, both the PSMC1A and
PSMC1B outputs are held tri-state until the
PSMC is configured. Driver circuitry for all
power MOSFET transistors must have a
resistor bias to turn off the transistor in the
event of tri-state conditions, on either
PSMC1A or PSMC1B, to prevent excessive stress on the MOSFET's and their
associated circuitry.
SMCOM bit (PSMCCON1<1>) determines the number
of outputs from the PSMC. When SMCOM is set, both
PSMC1A and PSMC1B are active. When SMCOM is
cleared, only the PSMC1A output is active and the
PSMC1B output is available for another function.
S1APOL and S1BPOL control the polarity of the PSMC
outputs. Setting the polarity bit configures the corresponding output for an active low state. Clearing the bit
results in an active high output.
PSMCCON0 REGISTER
The SMCCL<1:0> bits in the PSMCCON0 register, are
used to set the pulse frequency of the PSMC.
Note:
The SCEN bit (PSMCCON1<2>) enables the slope
compensation output. When SCEN is set (and SMCOM
is cleared) the PSMC1B output is configured to generate a slope compensation signal.
Changing SMCCL<1:0> bits with the
PSMC enabled (SMCON=1) can result in
unpredictable output. Always disable
PSMC before changing SMCCL<1:0>.
Note:
In the PWM mode, the MINDC <1:0> bits
(PSMCCON0 <5:4>) specify the minimum duty cycle.
TABLE 13-5:
PSMCCON1 REGISTER
PSMC outputs must have their corresponding direction bits cleared in TRISB;
TRISB<6>: for PSMC1A, and TRISB<7>
for PSMC1B.
PSMC OUTPUT MODES
PSMC
PORTB
FUNCTION
SMCOM
SCEN
TRISB<6>
Single Output
0
0
0
*
Single Output + Slope Compensation
0
1
0
0
x
0
0
Dual Output
1
Legend: x = Don’t Care
*As needed for other functions (such as C2, RB7, T1G).
DS41171B-page 104
Preliminary
TRISB<7>
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
REGISTER 13-1:
PSMC CONTROL REGISTER0 (PSMCCON0: 111h)
R/W-0
R/W-0
SMCCL1 SMCCL0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
MINDC1
MINDC0
MAXDC1
MAXDC0
DC1
DC0
bit 7
bit 0
bit 7-6
SMCCL<1:0>: Clock Frequency Select bits
00 = Output frequency for single output mode is FOSC/128
01 = Output frequency for single output mode is FOSC/64
10 = Output frequency for single output mode is FOSC/32
11 = Output frequency for single output mode is FOSC/16
bit 5-4
MINDC<1:0>: Minimum Duty Cycle Select bits for PWM Mode
00 = Min duty cycle of 0
01 = Min duty cycle of 1/8
10 = Min duty cycle of 1/4
11 = Min duty cycle of 3/8
bit 3-2
MAXDC<1:0>: Maximum Duty Cycle Select bits for PWM Mode
00 = Max duty cycle of 1/2
01 = Max duty cycle of 5/8
10 = Max duty cycle of 3/4
11 = Max duty cycle of 15/16
bit 1-0
DC<1:0>: Duty Cycle Select bits for PSM Mode
00 = Duty cycle of 1/8
01 = Duty cycle of 3/8
10 = Duty cycle of 5/8
11 = Duty cycle of 15/16
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
 2001-2013 Microchip Technology Inc.
Preliminary
x = Bit is unknown
DS41171B-page 105
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PIC16C781/782
REGISTER 13-2:
PSMC CONTROL REGISTER1 (PSMCCON1: 112h)
R/W-0
R/W-0
R/W-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
SMCON
S1APOL
S1BPOL
—
SCEN
SMCOM
PWM/PSM
SMCCS
bit 7
bit 0
bit 7
SMCON: PSMC Module Enable bit
1 = PSMC module on
0 = PSMC module off
bit 6
S1APOL: PSMC1A Output Polarity Control bit
1 = PSMC1A output signal is asserted low
0 = PSMC1A output signal is asserted high
bit 5
S1BPOL: PSMC1B Output Polarity Control bit
1 = PSMC1B output signal is asserted low
0 = PSMC1B output signal is asserted high
Unimplemented: Read as ’0
bit 4
bit 3
SCEN: Slope Compensation Output Enable bit
If SMCOM = 1:
x = This bit is ignored
If SMCOM = 0:
1 = Slope Compensation Switch on PSMC1B pin is enabled
0 = Slope Compensation Switch on PSMC1B pin is not enabled. PSMC1B pin is available for
other functions.
bit 2
SMCOM: PSMC Output Mode bit
1 = Dual alternating output mode. The module outputs are available on the PSMC1A and
PSMC1B pins.
0 = Single output mode. The module output is available on the PSMC1A pin.
bit 1
PWM/PSM: PSMC Modulation Mode Select bit
1 = PWM mode (Pulse Width Modulation)
0 = PSM mode (Pulse Skipping Modulation)
bit 0
SMCCS: PSMC Comparator Select bit
1 = PSMC module uses inputs from both C1OUT and C2OUT
0 = SMC module uses input from C1OUT only
Legend:
DS41171B-page 106
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
’1’ = Bit is set
’0’ = Bit is cleared
Preliminary
x = Bit is unknown
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
13.3
Configuration
The programmable nature of the PSMC lends itself to a
wide variety of applications involving current or voltage
management. The following examples are intended to
provide suggested applications for the PSMC. The
examples are not complete designs, but rather block
diagrams of some potential applications of the PSMC.
For a broader list of applications, including supporting
math and firmware examples, please refer to Microchip
web page for applicable Application Notes.
13.3.1
EXAMPLE BOOST LC SWITCHING
POWER SUPPLY
In this example, the PSMC controls the boost configuration switching power supply in Figure 13-5.
The PSMC is configured as a two feedback loop PWM,
current mode, switching power supply controller. The
inner current feedback loops consist of:
•
•
•
•
•
•
PSMC
MOSFET driver
Power MOSFET Q1
Inductor L1
Current transformer
Comparator C1
The inner current loop is a pulsed current source driven
by the PSMC. During the active phase of the output
pulse, the inner loop builds up a current flow in inductor
L1. The current in L1 is monitored by the current transformer. The output of the transformer is offset by the
ramp from the slope compensation network R3/C1 and
then fed into the comparator. When the voltage (proportional to the current flow in L1, offset by the slope
compensation) exceeds the error voltage from the
OPAMP, Q1 is turned off and L1 discharges through D1
into CMAIN for the remainder of the period.
The outer voltage loop monitors the output voltage
across CMAIN using R1/R2. The reference voltage from
the DAC is subtracted, generating the raw error voltage. The raw error voltage is filtered by the OPAMP
and routed to Comparator C1 in the inner current loop.
The phase compensation output of the PSMC acts to
improve loop stability by adding a pseudo-ramp waveform to the current sense transformer feedback in the
inner loop. In conditions where the charge phase of the
cycle is greater then 50%, the increased current feedback reduces the current charge in L1, slowing the
charging of CMAIN. The result is a reduction in the overall loop gain for duty cycles of >50%, maintaining loop
stability.
The outer voltage feedback loop consists of:
•
•
•
•
Diode D1
CMAIN
OPAMP feedback filter
DAC reference
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 107
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PIC16C781/782
FIGURE 13-5:
EXAMPLE BOOST CONFIGURATION LC SWITCHING POWER SUPPLY
+DCRAW
PIC16C781/782
L1
MOSFET
DRIVER
RB6/C1/PSMC1A
CURRENT TRANSFORMER
A
PSMC
RB7/C2/PSMC1B R3 VDD
SC
D1
+
Q1
LOAD
CMAIN
C1
RB3/AN7/OPA
R1
R2
RA1/AN1/OPA-
OPA
RA4/AN0/OPA+
RA3/AN3/VREF1
C1
RB2/AN6
RB1/AN5/VDAC
DAC
VREF
Note:
The OPAMP, Comparator and DAC must
be configured, prior to enabling the PSMC
to prevent unpredictable operation which
may stress the power MOSFET transistors.
DS41171B-page 108
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 109 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
EXAMPLE 13-1:
PSMC CONFIGURATION EXAMPLE
;* This code block will configure the PSMC and
;*
all additional peripherals for a boost mode
;*
switching power supply.
;*
;* Order of configuration
;* 1. PORTA/B I/O and analog configured
;* 2. DAC enabled, configured, and preset
;* 3. Op Amp enabled and configured
;* 4. Comparator C1 enabled and configured
;* 5. PSMC configured
;* 6. PSMC enabled
**********************************************************
;* This code block will configure all analog ports.
BANKSEL
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
TRISA
B’00001011’
TRISA
B’11001110’
TRISB
B’11101011’
ANSEL
; Select Bank 1
; Set RA0,1,& 3 as inputs
; Set RB1,2,3,6 & 7 as inputs
; Configure RA0, RA1, RA3,
; RB1, RB2, RB3 as analog
;**********************************************************************
;* This code block will configure the DAC for VDD as
;* DACREF, and RB1/AN5/VDAC as an output
BANKSEL
DACON0
; Select Bank 2
CLRF
MOVLW
MOVWF
DAC
B’11000000’
DACON0
; Set DAC to safe value
; Enable DAC, output
;
and set DACREF = VDD
MOVLW
OUTPUT_VALUE
MOVWF
DAC
; Set DAC output level
;**********************************************************************
;* This code block will configure the OPA module as an
;* Op Amp, with a 2MHz GBWP
MOVLW
MOVWF
B’10000001’
OPACON
; Set Op Amp mode and
; 2MHz GBWP
;*************************************************************************
;* This code block will configure Comparator C1
;* for normal speed and output polarity,
;* input on AN6, and Reference from the VREF1
MOVLW
MOVWF
B’10001010
CM1CON0
; Set C1, no ext out, norm
;
speed & pol, VREF1, AN6
;************************************************************************
;* This code block will configure the PSMC module
;* for PWM, FOSC/128, Single in, Single pulse out, slope comp out
;* Non-inverting out, DC min = 0%, DC max = 75%
MOVLW
MOVWF
MOVLW
MOVWF
BSF
B’00001000’
PSMCCON0
B’00001010’
PSMCCON1
PSMCCON1,SMCON
 2001-2013 Microchip Technology Inc.
;
;
;
;
Set DCmin 0, DCmax 75, FOSC/128
Set PWM Sngl in, Sngl out non-invert
Slope comp
Enable PSMC
Preliminary
DS41171B-page 109
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PIC16C781/782
13.3.2
EXAMPLE BUCK LC SWITCHING
POWER SUPPLY
In this example, the PSMC controls the buck configuration switching power supply in Figure 13-6.
The PSMC is configured as a typical PWM, current
mode, switching power supply controller. The inner current feedback loops consist of:
•
•
•
•
•
•
PSMC
2 MOSFET drivers
Power MOSFETs Q1 and Q2
Inductors L1 and L2
Current transformer
Comparator C1/C2
The outer voltage loop monitors the output voltage
across CMAIN via R1/R2. The reference voltage from
the DAC is subtracted from the feedback voltage to
generate the raw error voltage. The raw error voltage is
then filtered by the OPAMP and routed to Comparator
C1 in the inner current loop.
In using two alternating outputs, the outputs are limited
to less than 50% duty cycle. As a result, the circuit
avoids the problems associated with instability at duty
cycles of >50%.
For more information concerning the design of switching power supplies, refer to:
Switching Power Supply Design, by Abraham I. Pressman, published by McGraw Hill (ISBN 0-07-052236-7).
The outer voltage feedback loop consists of:
•
•
•
•
Note:
Diodes D1, D2, D3, and D4
CMAIN
OPAMP feedback filter
DAC reference
The circuit uses two feedback loops, an inner current
control loop, and an outer voltage loop. The inner loop
is further divided into two channels, Q1/L1, and Q2/L2.
The PSMC operates a PWM output, alternately driving
Q1 for a cycle, then driving Q2 the next. During the
active phase of either output pulse, the inner loop
builds up a current flow in the output’s inductor, proportional to the error voltage received from the OPAMP.
The current flow in the inductor begins the charging of
CMAIN. When the voltage (proportional to the current
flow in the inductor) exceeds the error voltage:
•
•
•
•
Following RESET, both the PSMC1A and
PSMC1B outputs are held tri-state until the
PSMC is configured. Driver circuitry for all
power MOSFET transistors must have a
resistor bias to turn off the transistor in the
event of tri-state conditions on either output to prevent undo stress on the MOSFET's and their associated circuitry.
The comparator resets the PSMC output
The MOSFET is turned off
The flyback diode forward biases
The inductor discharges into CMAIN for the
remainder of the period.
DS41171B-page 110
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
EXAMPLE 13-2:
EXAMPLE PSMC CONFIGURATION FOR A BUCK MODE SWITCHING POWER
SUPPLY
;* PSMC Initialization
;* This code block will configure the PSMC
;* and all additional peripherals for a buck
;* mode switching power supply.
;*
;* Order of configuration
;* 1. PORTA/B I/O and analog configured
;* 2. DAC enabled, configured, and preset
;* 3. Op Amp enabled and configured
;* 4. Comparator C1 enabled and configured
;* 5. PSMC configured
;* 6. PSMC enabled
;********************************************
;* This code block will configure all analog ports.
;
BANKSEL
TRISA
; Select Bank 1
MOVLW
B’00001011’
MOVWF
TRISA
; Set RA0,1,& 3 as inputs
MOVLW
B’11001110
MOVWF
TRISB
; Set RB1,2,3,6 & 7 as inputs
MOVLW
B’11101011’
MOVWF
ANSEL
; Set AN0,1,3,5,6 & 7 as analog
;*******************************************************
;* This code block will configure the DAC for VDD as
;* DACREF, and RB1/AN5/VDAC as an output.
BANKSEL
DACON0
; Select Bank 2
CLRF
MOVLW
MOVWF
DAC
B’11000000’
DACON0
; Set DAC to safe value
; Enable DAC, output
;
and set DACREF = VDD
MOVLW
MOVWF
OUTPUT_VALUE
DAC
; Set dAC output level
;*******************************************************
;* This code block will configure the OPA module
;* as an Op Amp, with a 3 MHZ GBWP
MOVLW
MOVWF
B’10000001’
OPACON
; Set Op Amp mode and
; 2 MHz GBWP
;********************************************************
;* This code block will configure Comparator C1
;* for normal speed and output polarity,
;* input on AN6, and Reference from the VREF1
MOVLW
MOVWF
B’10001010’
CM1CON0
; Set C1; no ext out, norm
; speed & pol, VREF1, AN6
;********************************************************
;* This code block will configure the PSMC module
;* for PWM, Fosc/128, Single input, Single output
;* Non-inverting out, DC min = 0%, DC max = 50%
MOVLW
MOVWF
MOVLW
MOVWF
BSF
B’0000000’
PSMCCON0
B’00000110’
PSMCCON1
PSMCCON1,SMCON
 2001-2013 Microchip Technology Inc.
; Set DCmin 0, DCmax 50, Fosc/128
; Set PWM, 1 in, 2 out, noninvert
; Enable PSMC
Preliminary
DS41171B-page 111
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PIC16C781/782
FIGURE 13-6:
EXAMPLE BUCK CONFIGURATION LC POWER SUPPLY
+VIN
CURRENT TRANSFORMER
PIC16C781/782
RB6/C1/PSMC1A
MOSFET
DRIVER
Q1
L1
D3
A
PSMC
D1
RB7/C2/PSMC1B/T1G
B
CMAIN
MOSFET
DRIVER
Q2
L2
D4
RA3/AN3/VREF1
+
C1
-
LOAD
D2
RB2/AN6
R1
RB3/AN7/OPA
RA1/AN1/OPA-
R2
OPA
+
RA0/AN0/OPA+
RB1/AN5/VDAC
VREF
13.3.3
DAC
EXAMPLE MOTOR SPEED
CONTROL
The algorithm (used to determine the values output by
the DAC module) depends on:
In Figure 13-7, the PSMC acts as a speed control for a
brushless DC motor. The direction of the current in the
motor winding is set by feedback from a Hall effect
position sensor on the motor. The sensor switches the
phase in the motor in response to the rotation of the
rotor so that the magnetic field rotates just ahead of the
rotor, pulling it in the desired direction. The speed at
which the rotor spins is a function of the mechanical
load on the rotor and the current in the field winding.
• mechanical system connected to the motor
• motor characteristics
• characteristics of the high current drive
An analysis of the mechanics of the system and the
design of an appropriate control algorithm is beyond
the scope of this Data Sheet. Therefore, the designer
should consult a text dealing with the design of motor
speed controls and feedback control system, in
general, for the necessary design guidance.
Speed control is accomplished by monitoring the speed
via the Hall effect sensor and regulating the current in
the winding appropriately. The winding current is regulated by the PSMC to be proportional to the value supplied by the DAC module. The feedback loop is closed
by software making periodic measurement of the rotor
speed using the Hall Effect sensor/Timer1 and adjusting the output value of the DAC appropriately.
DS41171B-page 112
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
EXAMPLE 13-3:
PERIPHERAL CONFIGURATION EXAMPLE
************************************************
;* This code block will configure the PSMC and
;* all additional peripherals for a motor speed
;* control.
;*
;* Order of configuration
;* 1. PORTA/B I/O and analog configured
;* 2. DAC enabled, configured, and preset
;* 3. Op Amp enabled and configured
;* 4. Comparator C1 enabled and configured
;* 5. PSMC configured
;* 6. PSMC enabled
;*
************************************************
;* This code block will configure all analog ports.
BANKSEL
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
TRISA
B’01000011’
TRISA
B’00001100’
TRISB
B’11000011’
ANSEL
; Select Bank 1
; Set RA0,1 & 6 as inputs
; Set RB2 & 3 as inputs
; Set AN0,1,6,& 7 as analog
;************************************************
;* This code block will configure the DAC for VR as
;* DACREF, and no output.
BANKSEL
BSF
BANKSEL
REFCON
REFCON, VREN
DACON0
; Enable VR
; Select Bank 2
CLRF
MOVLW
MOVWF
DAC
B’10000010’
DACON0
; Set DAC to safe value
; Enable DAC, no output
; and set DACREF = VR
MOVLW
MOVWF
OUTPUT_VALUE
DAC
; Set DAC output level
;************************************************
;* This code block will configure the OPA module
;* as an Op Amp, with a 2 MHz GBWP
MOVLW
MOVWF
B’10000001’
OPACON
; Set Op Amp mode and
; 2 MHz GBWP
;************************************************
*
This code block will configure Comparator C1
*
for normal speed and output polarity,
*
input on AN6, and Reference from the VDAC
MOVLW
MOVWF
B’10001110’
CM1CON0
; Set C1; no ext out, norm
; speed & pol, VDAC, AN6
;************************************************
;* This code block will configure the PSMC module
;* for PWM, Fosc/16, Single input, Single output
;* Non-inverting out, DC min = 0%, DC max = 94%
MOVLW
MOVWF
MOVLW
MOVWF
BSF
B’11001100’
PSMCCON0
B’00000010’
PSMCCON1
PSMCCON1,SMCON
 2001-2013 Microchip Technology Inc.
; Set DCmin 0, DCmax 94, Fosc/16
; Set PWM, Sngl in/out, noninvert
; Enable PSMC
Preliminary
DS41171B-page 113
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PIC16C781/782
FIGURE 13-7:
EXAMPLE BRUSHLESS D.C. MOTOR CONTROL
VMOTOR
PIC16C781/782
BRUSHLESS
H-BRIDGE
DRIVER
FOSC
/16
ENABLE
Q
S
D.C. MOTOR
HALL
EFFECT
SENSOR
RB6/C1/PSMC1A
PHASE
R
RSENSE
RB2/AN6
C1
RB3/AN7/OPA
RA0/AN0/OPA+
OPA
RA1/AN1/OPA-
VREF
FIRMWARE
FEEDBACK
CONTROL
DAC
RA6/OSC2/CLKOUT/T1CKI
TIMER 1
DS41171B-page 114
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PIC16C781/782
13.4
Effects of SLEEP and RESET
Placing the PIC16C781/782 into SLEEP mode will stop
the main oscillator for the microcontroller. The PSMC
derives its timing from the main oscillator. Therefore,
operation of the PSMC will halt when the microcontroller enters SLEEP mode. To prevent damage, the outputs of the PSMC are gated so that they are driven to
their inactive state whenever the device enters SLEEP
mode. When the microcontroller wakes up, the PSMC
resumes operation per its previously programmed configuration.
A device RESET forces all registers to their RESET
state. This disables the PSMC and resets its outputs to
digital inputs. It is good design practice to include a failsafe resistor bias in all power transistor drive circuitry.
The fail-safe circuit should disable the power device
when the PSMC output drive transistor is held tri-state.
This protects the power device and its associated circuitry from the stress of prolonged operation without
feedback.
TABLE 13-6:
Address
REGISTERS ASSOCIATED WITH THE PSMC
Name
86h,186h TRISB
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PORTB Data Direction Register
Value on:
POR,
BOR
Value on
all other
RESETS
1111 1111 1111 1111
11Ah
CM2CON0
C2ON
C2OUT
C2OE
C2POL
C2SP
C2R
C2CH1
C2CH0
0000 0000 0000 0000
119h
CM1CON0
C1ON
C1OUT
C1OE
C1POL
C1SP
C1R
C1CH1
C1CH0
0000 0000 0000 0000
111h
PSMCCON0 SMCCL1 SMCCL0 MINDC1 MINDC0 MAXDC1 MAXDC0
DC1
DC0
0000 0000 0000 0000
112h
PSMCCON1 SMCON S1APOL S1BPOL
—
SCEN
SMCOM PWM/PSM
SMCCS 000- 0000 000- 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for PSMC.
 2001-2013 Microchip Technology Inc.
Preliminary
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PIC16C781/782
NOTES:
DS41171B-page 116
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
14.0
SPECIAL FEATURES OF THE
CPU
These devices have a host of features intended to maximize system reliability, minimize cost through elimination of external components, provide power saving
operating modes and offer code protection. These features include:
• Oscillator selection
• RESET
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Programmable Brown-out Reset (PBOR)
• Interrupts
• Watchdog Timer (WDT)
• Programmable Low Voltage Detection (PLVD)
• SLEEP
• Code protection
• ID locations
• In-Circuit Serial ProgrammingTM (ICSPTM)
Note:
Address 2007h is beyond the user program memory space, which can be
accessed only during programming.
Some of the core features provided may not be necessary for each application in which a device may be
used. The configuration word bits allow these features
to be configured/enabled/disabled as necessary.
These features include:
•
•
•
•
•
Code Protection
PBOR Trip Point
Power-up Timer
Watchdog Timer
Device Oscillator Mode
As can be seen in Table 14-1, some additional configuration word bits have been provided for Brown-out
Reset trip point selection.
Several oscillator options are available to allow the part
to fit the application. The INTRC oscillator options save
system cost while the LP crystal option saves power. A
set of configuration bits is used to select various
options.
The CPU also features a Watchdog Timer (WDT),
which can be enabled either through a configuration bit
during programming, or by the software. For added reliability, the WDT runs off its own internal RC oscillator
instead of the main CPU clock.
In addition to the WDT, the CPU incorporates both an
Oscillator Start-up Timer and a Power-up Timer. The
Oscillator Start-up Timer (OST) is intended to hold the
chip in RESET until the crystal oscillator has stabilized.
The Power-up Timer (PWRT) holds the CPU in a fixed
RESET delay of 72ms (nominal) on Power-up Resets
(POR and PBOR), while the power supply stabilizes.
With these two timers on-chip, most applications need
no external RESET circuitry.
SLEEP mode is designed to offer a very low current
power-down mode. The user can awaken from SLEEP
through:
• External RESET
• Watchdog Timer Wake-up
• Interrupt
Additional information on special features is available
in the PIC Mid-Range Reference Manual, (DS33023).
14.1
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 in program memory location 2007h.
 2001-2013 Microchip Technology Inc.
Preliminary
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PIC16C781/782
REGISTER 14-1:
CP
CP
CONFIGURATION WORD FOR PIC16C781/782 DEVICE (CONFIG:2007h)
BORV1 BORV0
CP
CP
—
BODEN MCLRE PWRTE WDTE
F0SC2
F0SC1
bit13
F0SC0
bit0
bit 13-12,
9-8
CP: Program Memory Code Protection bits
1 = Code Protection off
0 = All program memory is protected(1)
bit 11-10
BORV<1:0>: Brown-out Reset Voltage bits
00 = PBOR set to 4.5V
01 = PBOR set to 4.2V
10 = PBOR set to 2.7V
11 = PBOR set to 2.5V
bit 7
Unimplemented: Read as ‘1’
bit 6
BODEN: Brown-out Detect Reset Enable bit(1)
1 = Brown-out Detect Reset enabled
0 = Brown-out Detect Reset disabled
bit 5
MCLRE: RA5/MCLR Pin Function Select bit
1 = RA5/MCLR pin function is MCLR
0 = RA5/MCLR pin function is digital input, MCLR internally tied to VDD
bit 4
PWRTE: Power-up Timer Enable bit(1)
1 = PWRT disabled
0 = PWRT enabled
bit 3
WDTE: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
bit 2-0
FOSC<2:0>: Oscillator Selection bits
FOSC<2:0>
000
OSCILLATOR RA6/OSC2/CLKOUT/T1CKI
LP
Crystal/Resonator
RA7/OSC1/CLKIN
Crystal/Resonator
001
XT
Crystal/Resonator
Crystal/Resonator
010
HS
Crystal/Resonator
Crystal/Resonator
011
EC
Digital I/O
CLKIN
100
INTRC
Digital I/O
Digital I/O
101
INTRC
CLKOUT
Digital I/O
110
RC
Digital I/O
RC
111
RC
CLKOUT
RC
Note 1: All of the CP bits must be given the same value to enable code protection.
DS41171B-page 118
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PIC16C781/782
14.2
Oscillator Configurations
14.2.1
TABLE 14-1:
OSCILLATOR TYPES
Ranges Tested:
The PIC16C781/782 can be operated in eight different
oscillator modes. The user can program three configuration bits FOSC<2:0> to select one of these eight
modes:
•
•
•
•
LP
XT
HS
RC
Low Power Crystal
Crystal/Resonator
High Speed Crystal/Resonator
External Resistor and Capacitor (with
and without CLKOUT)
• INTRC Internal 4 MHz/37 kHz (with and without
CLKOUT)
• EC
External Clock
14.2.2
Mode
Freq
In LP, XT, or HS modes, a crystal or ceramic resonator
is connected to the RA7/OSC1/CLKIN and RA6/OSC2/
CLKOUT/T1CKI pins to establish oscillation
(Figure 14-1). The PIC16C781/782 oscillator design
requires the use of a parallel cut crystal. Use of a series
cut crystal may yield a frequency outside of the crystal
manufacturers’ specifications.
C1(1)
CRYSTAL/CERAMIC
RESONATOR OPERATION
(HS, XT OR LP
OSC CONFIGURATION)
PIC16C781/782
RA7/OSC1/
CLKIN
To
Internal
Logic
XTAL
RA6/OSC2
CLKOUT/
T1CKI
RF(3)
SLEEP
Rs(2)
C2(1)
C2
455 kHz
68 - 100 pF
68 - 100 pF
2.0 MHz
15 - 68 pF
15 - 68 pF
4.0 MHz
15 - 68 pF
15 - 68 pF
HS
8.0 MHz
10 - 68 pF
10 - 68 pF
16.0 MHz
10 - 22 pF
10 - 22 pF
These values are for design guidance only.
See Notes 1 and 2 in shaded box.
In this test, all resonators used did not have built-in
capacitors.
TABLE 14-2:
Osc Type
LP
XT
HS
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
Crystal
Freq
Cap. Range
C1
Cap. Range
C2
32 kHz
33 pF
200 kHz
15 pF
33 pF
15 pF
200 kHz
47-68 pF
47-68 pF
1 MHz
15 pF
15 pF
4 MHz
15 pF
15 pF
4 MHz
15 pF
15 pF
8 MHz
15-33 pF
15-33 pF
20 MHz
15-33 pF
15-33 pF
These values are for design guidance only.
See Notes 1 and 2 in shaded box.
Note 1: Since each resonator/crystal has its own
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate values of external components.
2: Higher capacitance increases the stability
of oscillator but also increases the
start-up time.
Note 1: See Table 14-1 and Table 14-2 for recommended values of C1 and C2.
2: A series resistor (RS) may be required for
AT strip cut crystals.
C1
XT
LP, XT AND HS MODES
FIGURE 14-1:
CERAMIC RESONATORS
14.2.3
EC MODE
3: RF varies with the crystal chosen.
In applications where the clock source is external, the
PIC16C781/782 should be programmed to select the
EC (External Clock) mode. In this mode, the RA6/
OSC2/CLKOUT/T1CKI pin is available as an I/O pin.
See Figure 14-2 for illustration. To minimize power supply current drawn, the EC oscillator input should be
driven by a CMOS level square wave.
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
FIGURE 14-2:
EC OSC
CONFIGURATION
RA7
FIGURE 14-3:
RC OSCILLATOR MODE
VDD
PIC16C781/782
PIC16C781/782
RA7/OSC1/CLKIN
Clock from
ext. system
REXT
I/O
RA7/OSC1/
CLKIN
RA6/OSC2/CLKOUT/
T1CKI
Internal
Clock
CEXT
14.2.4
VSS
RC MODE
FOSC/4
For timing insensitive applications, the RC device
option offers additional cost savings. The RC oscillator
frequency is a function of:
14.2.5
• supply voltage
• resistor (REXT) and capacitor (CEXT) values
• operating temperature
In addition, the oscillator frequency varies from unit to
unit due to normal process variation. The difference in
lead frame capacitance between package types also
affects the oscillation frequency, especially for low
CEXT values. The user should allow for variations due
to tolerance of external R and C components used.
Figure 14-3 shows how the RC combination is connected to the PIC16C781/782. For REXT values below
2.2 k, the oscillator operation may become unstable
or stop completely. For very high REXT values (e.g., 1
Mor greater), the oscillator becomes sensitive to:
• noise
• humidity
• leakage
Microchip recommends keeping REXT between 3 k
and 100 k.
Although the oscillator will operate with no external
capacitor (CEXT = 0 pF), we recommend using values
above 20 pF for noise and stability reasons. With no or
small external capacitance, the oscillation frequency
can vary dramatically due to changes in external
capacitances, such as board trace capacitance or
package lead frame capacitance.
RA6/OSC2/CLKOUT/I1CKI
INTRC MODE
The internal RC oscillator provides a fixed 4 MHz/37
kHz (nominal) system clock at VDD = 5V and 25°C. See
Section 18.0 for information on variations over voltage
and temperature ranges. The INTRC oscillator does
not run during RESET.
14.2.6
DUAL SPEED OPERATION FOR
INTRC MODE
A software programmable slow speed mode is available with the INTRC oscillator. This feature allows the
firmware to dynamically toggle the oscillator speed
between normal and slow frequencies. The nominal
slow frequency is 37 kHz. Applications that require low
current power savings, but cannot tolerate putting the
part into SLEEP, may use this mode.
The OSCF bit (PCON<3>) is used to control dual
speed mode. See the PCON Register, Register 2-6, for
details.
When changing the INTRC internal oscillator speed,
there is a brief period of time when the processor is
inactive. When the speed changes from fast to slow,
the processor inactive period is in the range of 100 S
to 300 S. For a speed change from slow to fast, the
processor is inactive between 1.25 S and 3.25 S,
nominal.
See Section 18.0 for RC frequency variation from part
to part due to normal process variation. The variation is
greater for large values of R (since leakage current
variations affect RC frequency more for large R) and for
small values of C (since variations of input capacitance
affect RC frequency more).
14.2.7
See Section 18.0 for variation of oscillator frequency
due to VDD for given REXT and CEXT values (or for frequency variation due to operating temperature for
given R, C, and VDD values).
In the INTRC and RC modes, if the CLKOUT output is
enabled, CLKOUT is held low during RESET.
DS41171B-page 120
CLKOUT
In the INTRC and RC modes, the PIC16C781/782 can
be configured to provide a clock out signal by programming the configuration word. The oscillator frequency,
divided by 4, can be used for test purposes or to synchronize other logic.
Preliminary
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PIC16C781/782
14.3
RESET
The PIC16C781/782 devices have several different
RESETS. These RESETS are grouped into two classifications: power-up and non power-up. The power-up
type RESETS are the Power-on and Brown-out
Resets, which assume the device VDD was below its
normal operating range for the device’s configuration.
The non power-up type RESETS assume normal operating limits were maintained before/during and after the
RESET.
• Power-on Reset (POR)
• Programmable Brown-out Reset (PBOR)
• Non Power-up (MCLR) Reset during normal
operation
• MCLR Reset during SLEEP
• WDT Reset (during normal operation)
FIGURE 14-4:
Some registers are not affected in any RESET condition. Their status is unknown on a Power-up Reset and
unchanged in any other RESET. Most other registers
are placed into an initialized state upon RESET. However, they are not affected by a WDT Reset during
SLEEP, because this is considered a WDT Wake-up,
which is viewed as the resumption of normal operation.
Several status bits have been provided to indicate
which RESET occurred (see Table 14-4). See
Table 14-5 for a full description of RESET states of
special registers.
A simplified block diagram of the On-Chip Reset Circuit
is shown in Figure 14-4.
These devices have a MCLR noise filter in the MCLR
Reset path. The filter detects and ignores small pulses.
It should be noted that a WDT Reset does not drive
MCLR pin low.
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
RA5/MCLR/VPP
External
RESET
SLEEP
WDT Time-out
Module
VDD
VDD Rise
Detect
Power-on Reset
Programmable
BODEN
Brown-out
RA7/OSC1/
CLKIN
S
OST/PWRT
OST
10-bit Ripple Counter
R
Q
Chip_Reset
PWRT
Dedicated
Oscillator
10-bit Ripple Counter
Enable PWRT
Enable OST
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PIC16C781/782
14.4
Power-on Reset (POR)
14.5
A Power-on Reset pulse is generated on-chip when a
VDD rise is detected (in the range of 1.5V - 2.1V). To
take advantage of the POR, simply enable the internal
MCLR feature. This eliminates external RC components usually needed to create a Power-on Reset. A
maximum rise time for VDD is specified. See
Section 17.0 for details. For a slow rise time, see
Figure 14-5.
Two delay timers (PWRT on OST) are provided, which
hold the device in RESET after a POR (dependent
upon device configuration), so that all operational
parameters have been met prior to releasing the device
to resume/begin normal operation.
When the device starts normal operation (exits the
RESET condition), device operating parameters (i.e.,
voltage, frequency, temperature,...) 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. Brown-out Reset may be used to meet
the start-up conditions, or if necessary an external POR
circuit may be implemented to delay end of RESET for
as long as needed.
FIGURE 14-5:
EXTERNAL POWER-ON
RESET CIRCUIT (FOR
SLOW VDD RAMP)
VDD
VDD
PIC16C781/782
D
R
R1
MCLR
C
Note 1: External Power-on Reset circuit is required
only if 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
voltage drop across R does not violate the
device’s electrical specification.
3: R1 = 100 to 1 k will limit any current flowing into MCLR from external capacitor C in
the event of MCLR pin breakdown due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS).
Power-up Timer (PWRT)
The Power-up Timer provides a fixed TPWRT time-out
on power-up type RESETS only. For a POR, the PWRT
is invoked when the POR pulse is generated. For a
BOR, the PWRT is invoked when the device exits the
RESET condition (VDD rises above BOR trip point).
The Power-up Timer operates on an internal RC oscillator. The chip is kept in RESET as long as the PWRT
is active. The PWRT’s time delay is designed to allow
VDD to rise to an acceptable level. A configuration bit
(PWRT) is provided to enable/disable the PWRT for the
POR only. For a BOR the PWRT is always available
regardless of the configuration bit setting.
The power-up time delay varies from chip-to-chip due
to VDD, temperature and process variation. See DC
parameters for details.
14.6
Programmable Brown-out Reset
(PBOR)
The Programmable Brown-out Reset module is used to
generate a RESET when the supply voltage falls below
a specified trip voltage. The trip voltage is configurable
to any one of four voltages provided by the BORV<1:0>
configuration word bits.
Configuration bit BODEN can disable (if clear/programmed), or enable (if set), the Brown-out Reset circuitry. If VDD falls below the specified trip point for
longer than TBOR (see Parameter 35, Section 17.0,
Table 17-6), the brown-out situation resets the chip. A
RESET may not occur if VDD falls below the trip point
for less than TBOR. The chip remains in Brown-out
Reset until VDD rises above VBOR. The Power-up Timer
is invoked at that point and keeps the chip in RESET an
additional TPWRT. If VDD drops below VBOR while the
Power-up Timer is running, the chip goes back into a
Brown-out Reset and the Power-up Timer is reinitialized. Once VDD rises above VBOR, the Power-up
Timer again begins a TPWRT time delay.
14.7
Time-out Sequence
On power-up, the time-out sequence is as follows:
First, PWRT time-out is invoked by the POR pulse.
When the PWRT delay expires, the Oscillator Start-up
Timer is activated. The total time-out varies depending
on oscillator configuration and the status of the PWRT.
For example, in RC mode with the PWRT disabled,
there is no time-out at all. Figure 14-6, and Figure 14-9
depict time-out sequences on power-up.
Since the time-outs occur from the POR pulse, if MCLR
is kept low long enough, the time-outs expire. Then,
bringing MCLR high begins execution immediately.
This is useful for testing purposes or to synchronize
more than one PIC microcontroller operating in parallel.
Table 14-5 shows the RESET conditions for some special function registers.
DS41171B-page 122
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PIC16C781/782
14.8
Power Control/Status Register
(PCON)
Clearing the OSCF (PCON<3>) enables oscillation at
37kHz, setting OSCF returns the oscillator to operation
at 4MHz.
The Power Control/Status Register, PCON, has two
status bits that provide indication of which power-up
type RESET occurred.
The Watchdog Timer is a free running, on-chip dedicated oscillator and timer, which does not require any
external components to operate. The WDT provides a
system RESET in the event that software does not execute a CLRWDT instruction within a specified interval.
For reliability, the WDT will run even if the CPU clock
has been stopped (for example, by the execution of a
SLEEP instruction).
PCON<0> is Brown-out Reset Status bit, BOR. Bit
BOR is set on a Power-on Reset. It must then be set by
the user and checked on subsequent RESETS to see
if bit BOR cleared, indicating a BOR occurred. However, if the brown-out circuitry is disabled, the BOR bit
is a "Don’t Care" bit and is considered unknown upon a
POR.
During normal operation, a WDT time-out generates a
device RESET (Watchdog Timer Reset). If the device is
in SLEEP mode, a WDT time-out causes the device to
awaken and resume normal operation (Watchdog
Timer Wake-up).
PCON<1> is POR (Power-on Reset Status bit). It is
cleared on a Power-on Reset and unaffected otherwise. The user must set this bit following a Power-on
Reset.
The WDT can be enabled either by setting the WDTE
bit in the configuration register during programming, or
by setting the WDTON bit (PCON<4>).
When the CPU is running under the INTRC oscillator
mode, the frequency of the INTRC oscillator can be
switched to a power saving 37 kHz (nominal) mode.
TABLE 14-3:
TIME-OUT IN VARIOUS SITUATIONS
Power-up
Brown-out
Wake-up from
SLEEP
1024TOSC
TPWRT + 1024TOSC
1024TOSC
—
TPWRT
—
Oscillator Configuration
XT, HS, LP
PWRTE = 0
PWRTE = 1
TPWRT + 1024TOSC
TPWRT
EC, RC, INTRC
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PIC16C781/782
REGISTER 14-2:
POWER CONTROL REGISTER (PCON: 8Eh)
U-0
U-0
U-0
R/W-q
R/W-1
U-0
R/W-q
R/W-x
—
—
—
WDTON
OSCF
—
POR
BOR
bit 7
bit 0
bit 7-5
Unimplemented: Read as '0'
bit 4
WDTON: WDT Software Enable bit
If WDTE bit (Configuration Word <3>) = 1:
This bit is not writable, always reads ‘1’
If WDTE bit (Configuration Word <3>) = 0:
1 = WDT is enabled
0 = WDT is disabled and cleared
bit 3
OSCF: Oscillator Speed bit (pending on new internal oscillator decision)
INTRC mode:
1 = 4 MHz typical
0 = 37 kHz typical
All other oscillator modes:
Ignored
bit 2
Unimplemented: Read as '0'
bit 1
POR: Power-on Reset Status bit
1 = No Power-on Reset occurred
0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)
bit 0
BOR: Brown-out Reset Status bit
1 = No Brown-out Reset occurred
0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs)
Legend:
TABLE 14-4:
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
’q’ = Value depends on condition
STATUS BITS AND THEIR SIGNIFICANCE
POR
BOR
TO
PD
0
1
1
1
Power-on Reset
Bit Significance
0
x
0
x
Illegal, TO is set on POR
0
x
x
0
Illegal, PD is set on POR
1
0
1
1
Brown-out Reset
1
1
0
1
WDT Reset
1
1
0
0
WDT Wake-up
1
1
u
u
MCLR Reset during normal operation
1
1
1
0
MCLR Reset during SLEEP or interrupt wake-up from SLEEP
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TABLE 14-5:
RESET CONDITION FOR SPECIAL REGISTERS
Program
Counter
STATUS
Register
PCON
Register
Power-on Reset
000h
0001 1xxx
---0 1-01
MCLR Reset during normal operation
000h
000u uuuu
---0 1-uu
MCLR Reset during SLEEP
000h
0001 0uuu
---0 1-uu
WDT Reset
000h
0000 1uuu
---0 1-uu
PC + 1
uuu0 0uuu
---0 u-uu
Condition
WDT Wake-up
Brown-out Reset
000h
0001 1uuu
---0 1-u0
Interrupt wake-up from SLEEP, GIE = 0
PC + 1
uuu1 0uuu
---u u-uu
Interrupt wake-up from SLEEP, GIE = 1
0004h
uuu1 0uuu
---u u-uu
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0'.
FIGURE 14-6:
TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 14-7:
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
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TABLE 14-6:
INITIALIZATION CONDITION FOR ALL REGISTERS
Register
Power-On Reset or
Brown-Out Reset
MCLR Reset or
WDT Reset
Wake-up via WDT or
Interrupt
W (not a mapped register)
INDF
TMR0
xxxx xxxx
0000 0000
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
PCL
0000 0000
0000 0000
PC + 1(1)
quuu(2)
STATUS
0001 1xxx
000q
uuuq quuu(2)
FSR
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTA
xxxx 0000
uuuu 0000
uuuu uuuu
PORTB
xxxx xx00
uuuu uu00
uuuu uu00
PCLATH
---0 0000
---0 0000
---u uuuu
INTCON
0000 000x
0000 000u
uuuu uuqq
PIR1
0000 ---0
0000 ---0
0000 ---u
CALCON
000- ---000- ---uuu- ---TMR1L
xxxx xxxx
uuuu uuuu
uuuu uuuu
TMR1H
xxxx xxxx
uuuu uuuu
uuuu uuuu
T1CON
-000 0000
-uuu uuuu
-uuu uuuu
PSMCCON0
0000 0000
0000 0000
uuuu uuuu
PSMCCON1
000- 0000
000- 0000
uuu- uuuu
CM1CON0
0000 0000
0000 0000
uuuu uuuu
CM2CON0
0000 0000
0000 0000
uuuu uuuu
CM2CON1
00-- ---0
00-- ---0
uu-- ---u
OPACON
00-- ---0
00-- ---0
uu-- ---u
ADRES
xxxx xxxx
uuuu uuuu
uuuu uuuu
ADCON0
0000 0000
0000 0000
uuuu uuuu
OPTION_REG
1111 1111
1111 1111
uuuu uuuu
TRISA
1111 1111
1111 1111
uuuu uuuu
TRISB
1111 1111
1111 1111
uuuu uuuu
PIE1
0000 ---0
0000 ---0
uuuu ---u
PCON
---0 1-qq
---0 1-uu
---u u-uu
DAC
0000 0000
0000 0000
uuuu uuuu
DACON0
00-- --00
00-- --00
uu-- --uu
WPUB
1111 1111
1111 1111
uuuu uuuu
IOCB
1111 0000
1111 0000
uuuu uuuu
REFCON
---- 00----- 00----- uu-LVDCON
--00 0101
--00 0101
--uu uuuu
ANSEL
1111 1111
1111 1111
uuuu uuuu
ADCON1
--00 -----00 -----uu ---PMDATL
xxxx xxxx
uuuu uuuu
uuuu uuuu
PMADRL
xxxx xxxx
uuuu uuuu
uuuu uuuu
PMDATH
--xx xxxx
--uu uuuu
--uu uuuu
PMADRH
---- xxxx
---- uuuu
---- uuuu
PMCON1
1--- ---0
1--- ---0
1--- ---0
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition
Note 1: When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt
vector (0004h).
2: See Table 14-5 for RESET value for specific condition.
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FIGURE 14-8:
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 14-9:
SLOW VDD RISE TIME (MCLR TIED TO VDD)
5V
VDD
0V
MCLR
INTERNAL POR
TPWRT
(1)
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
Note 1: This time depends on the oscillator circuit used.
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14.9
Interrupts
When an interrupt is serviced, the GIE bit is cleared to
disable any further interrupt. The return address is
pushed onto the stack and the PC is loaded with 0004h.
Once in the Interrupt Service Routine the source(s) of
the interrupt can be determined by polling the interrupt
flag bits. The interrupt flag bit(s) must be cleared in software before re-enabling interrupts to avoid recursive
interrupts.
The devices have up to eight sources of interrupt. The
interrupt control register (INTCON) records individual
interrupt requests in flag bits. It also has individual and
global interrupt enable bits.
Note:
Individual interrupt flag bits are set, regardless of the status of their corresponding
mask bit or the GIE bit.
For external interrupt events, such as the INT pin or
PORTB change interrupt, the interrupt latency is three
or four instruction cycles. The exact latency depends
on when the interrupt event occurs. The latency is the
same for one or two-cycle instructions. Individual interrupt flag bits are set, regardless of the status of their
corresponding mask bit or the GIE bit.
A global interrupt enable bit, GIE (INTCON<7>),
enables (if set) all unmasked interrupts or disables (if
cleared) all interrupts. When bit GIE is enabled and an
interrupt’s flag bit and mask bit are set, the interrupt will
vector immediately. Individual interrupts can be disabled through their corresponding enable bits in various registers. Individual interrupt bits are set,
regardless of the status of the GIE bit. The GIE bit is
cleared on RESET.
14.9.1
The “return from interrupt” instruction, RETFIE, exits
the interrupt routine as well as sets the GIE bit, which
re-enables interrupts.
The RB0/INT/AN4/VR pin interrupt, the RB port Interrupt-on-Change (IOCB) and the TMR0 overflow interrupt flags are contained in the INTCON register.
The peripheral interrupt flags are contained in the special function register PIR1. The corresponding interrupt
enable bits are contained in special function register
PIE1, and the peripheral interrupt enable bit is contained in special function register INTCON.
FIGURE 14-10:
INTERRUPT LOGIC
T0IF
T0IE
LVDIF
LVDIE
INTF
INTE
C2IF
C2IE
RBIF
RBIE
C1IF
C1IE
ADIF
ADIE
INT INTERRUPT
External interrupt on RB0/INT/AN4/VR pin is edge triggered: either rising, if bit INTEDG (OPTION_REG<6>)
is set, or falling, if the INTEDG bit is clear. When a valid
edge appears on the RB0/INT pin, flag bit INTF
(INTCON<1>) is set. This interrupt can be disabled by
clearing enable bit INTE (INTCON<4>). Flag bit INTF
must be cleared in software in the Interrupt Service
Routine before re-enabling this interrupt. The INT interrupt can awaken the processor from SLEEP, if bit INTE
was set prior to going into SLEEP. The status of global
interrupt enable bit GIE decides whether or not the processor branches to the interrupt vector following a
wake-up sequence. See Section 14.12 for details on
SLEEP mode.
Wake-up (If in SLEEP mode)
Interrupt to CPU
PEIF
PEIE
GIE
TMR1IF
TMR1IE
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14.9.2
TMR0 INTERRUPT
EXAMPLE 14-1:
An overflow (FFh  00h) in the TMR0 register sets the
flag bit, T0IF (INTCON<2>). The interrupt can be
enabled/disabled by setting/clearing enable bit, T0IE
(INTCON<5>) (Section 2.5).
14.9.3
PORTB INTERRUPT-ON-CHANGE
(IOCB)
An input change on PORTB<7:0> sets flag bit RBIF
(INTCON<0>). The PORTB pin(s) which can individually generate interrupt are selectable in the IOCB register. The interrupt can be enabled/disabled by setting/
clearing enable bit RBIE (INTCON<4>) (Section 2.5).
PORTB must be configured as a digital input.
14.10 Context Saving During Interrupts
During an interrupt, only the PC is saved on the stack.
At minimum, W and STATUS should be saved to preserve the context for the interrupted program. All registers that may be corrupted by the Interrupt Service
Routine (ISR), such as PCLATH or FSR, should be
saved.
Example 14-1 stores and restores the STATUS, W and
PCLATH registers. The register, W_TEMP, is defined in
Common RAM, the last 16 bytes of each bank that may
be accessed from any bank. The STATUS_TEMP and
PCLATH_TEMP are defined in bank 0.
Stores the W register.
Stores the STATUS register in bank 0.
Stores the PCLATH register in bank 0.
Executes the ISR code.
Restores the PCLATH register.
Restores the STATUS register.
Restores W.
Note:
#define
W_TEMP
0x70
#define
STATUS_TEMP
0x71
#define
PCLATH_TEMP
0x72
org
0x04
; Int Vector
MOVWF
W_TEMP
; Save W
MOVF
STATUS,w
MOVWF
STATUS_TEMP
; save STATUS
MOVF
PCLATH,w
MOVWF
PCLATH_TEMP
; save PCLATH
:
(Interrupt Service Routine)
:
MOVF
PCLATH_TEMP,w
MOVWF
PCLATH
MOVF
STATUS_TEMP,w
MOVWF
STATUS
SWAPF
W_TEMP,f
; swapf loads W
SWAPF
W_TEMP,w
; w/o affect STATUS
RETFIE
14.11 Watchdog Timer (WDT)
The Watchdog Timer uses a free running, on-chip RC
oscillator, which does not require any external components. This oscillator is independent from the processor
clock. The WDT runs even if the main clock of the
device has been stopped (for example, by execution of
a SLEEP instruction).
During normal operation, a WDT time-out generates a
device RESET (Watchdog Timer Reset). If the device is
in SLEEP mode, a WDT time-out causes the device to
wake-up and continue with normal operation (Watchdog Timer Wake-up). The TO bit in the STATUS register is cleared upon a Watchdog Timer time-out.
The example:
a)
b)
c)
d)
e)
f)
g)
SAVING STATUS, W, AND
PCLATH REGISTERS
The WDT can be permanently enabled by programming the configuration bit WDTE, or by software via the
WDTON bit in the Power Control register (PCON:
8EH). See Section 14.8 and Section 14.1.
The W_TEMP, STATUS_TEMP and
PCLATH_TEMP are defined in the common RAM area (70h - 7Fh) to avoid register bank switching during context save and
restore.
WDT time-out period values may be found in the Electrical Specifications. Values for the WDT prescaler may
be assigned using the OPTION_REG register.
Note 1: The CLRWDT and SLEEP instructions
clear the WDT and the postscaler, if
assigned to the WDT.
2: When a CLRWDT instruction is executed
and the prescaler is assigned to the WDT,
the prescaler count is cleared, but the
prescaler assignment is not changed.
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FIGURE 14-11:
WATCHDOG TIMER BLOCK DIAGRAM
From TMR0 Clock Source
(Figure 5-2)
WDTE(2)
0
WDT Timer
WDTON(3)
Postscaler
M
1 U
X
8
PS<2:0>(1)
8 - to - 1 MUX
PSA(1)
To TMR0 (Figure 5-2)
0
1
PSA(1)
MUX
WDT
Time-out
Note 1: PSA and PS<2:0> are bits in the OPTION_REG register.
2: WDTE bit in the configuration word.
3: WDTON bit in the PCON register.
TABLE 14-7:
Address
SUMMARY OF WATCHDOG TIMER REGISTERS
Name
Bits(1)
2007h
Config.
81h,181h
OPTION_REG
8Eh
PCON
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
FOSC0
—
BODEN
MCLRE
PWRTE
WDTE
FOSC2
FOSC1
RBPU
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
—
—
—
WDTON
OCSF
—
BOR
POR
Legend: Shaded cells are not used by the Watchdog Timer.
Note 1: See Register 14-1 for the full description of the Configuration Word bits.
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14.12 Power-down Mode (SLEEP)
Power-down mode is entered by executing a SLEEP
instruction.
If enabled, the Watchdog Timer is cleared but keeps
running, the PD bit (STATUS<3>) is cleared, the TO
(STATUS<4>) bit is set, and the oscillator driver is
turned off. The I/O ports maintain the status they had,
before the SLEEP instruction was executed (driving
high, low, or hi-impedance).
For lowest current consumption in this mode:
• place all I/O pins at either VDD, or VSS,
• ensure no external circuitry is drawing current
from the I/O pin,
• power-down all peripherals,
• disable external clocks.
WAKE-UP FROM SLEEP
The device can wake-up from SLEEP through one of
the following events:
1.
2.
3.
External RESET input on MCLR pin.
Watchdog Timer Wake-up (if WDT was
enabled).
Interrupt from INT pin, PORTB IOCB, or any
Peripheral Interrupts.
External MCLR Reset causes a device RESET. All other
events are considered a continuation of program execution and cause a "wake-up". The TO and PD bits in the
STATUS register can be used to determine the cause of
device RESET. The PD bit, which is set on power-up, is
cleared when SLEEP is invoked. The TO bit is cleared if
a WDT time-out occurred (and caused wake-up).
The following peripheral interrupts can wake the device
from SLEEP:
1.
2.
3.
4.
5.
When the SLEEP instruction is being executed, the next
instruction (PC + 1) is pre-fetched. For the device to
wake-up through an interrupt event, the corresponding
interrupt enable bit must be set (enabled). Wake-up is
regardless of the state of the GIE bit. If the GIE bit is
clear (disabled), the device continues execution at the
instruction after the SLEEP instruction. If the GIE bit is
set (enabled), the device executes the instruction after
the SLEEP instruction, then branches to the interrupt
address (0004h). In cases where the execution of the
instruction following SLEEP is not desirable, the user
should have a NOP after the SLEEP instruction.
14.12.2
Pull all I/O pins that are hi-impedance inputs, high or low
externally to avoid switching currents caused by floating
inputs. The T0CKI input should also be at VDD or VSS for
lowest current consumption. The contribution from onchip pull-ups on PORTB should be considered.
14.12.1
Other peripherals cannot generate interrupts since during SLEEP, no on-chip clocks are present.
WAKE-UP USING INTERRUPTS
When global interrupts are disabled (GIE cleared) and
any interrupt source has both its interrupt enable bit
and interrupt flag bit set, one of the following will occur:
• If the interrupt occurs before the execution of a
SLEEP instruction, the SLEEP instruction completes as a NOP. Therefore, the WDT and WDT
postscaler are not cleared, the TO bit is not set,
and PD bits are not cleared.
• If the interrupt occurs during or after the execution of a SLEEP instruction, the device immediately awakens from SLEEP. The SLEEP
instruction will be completely executed before the
wake-up. Therefore, the WDT and WDT
postscaler are cleared, the TO bit is set, and the
PD bit is cleared.
Even if the flag bits were checked before executing a
SLEEP instruction, it may be possible for flag bits to
become set before the SLEEP instruction completes. To
determine whether a SLEEP instruction executed, test
the PD bit. If the PD bit is set, the SLEEP instruction
was executed as a NOP.
To ensure that the WDT is cleared, a CLRWDT instruction should be executed before a SLEEP instruction.
TMR1 interrupt. Timer1 must be operating as an
asynchronous counter.
ADC conversion (when ADC clock source is RC).
Programmable low voltage detect.
Comparator C1 or C2 interrupt-on-change.
OPA in Comparator mode using IOCB.
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FIGURE 14-12:
WAKE-UP FROM SLEEP THROUGH INTERRUPT
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
TOST(1)
CLKOUT(3)
INT pin
INTF flag
(INTCON<1>)
GIE bit
(INTCON<7>)
Interrupt Latency(2)
Processor in
SLEEP
INSTRUCTION FLOW
PC
Instruction
Fetched
Instruction
Executed
Note
1:
2:
3:
PC
Inst(PC) = SLEEP
Inst(PC - 1)
PC+1
PC+2
PC+2
Inst(PC + 1)
Inst(PC + 2)
SLEEP
Inst(PC + 1)
PC + 2
Dummy cycle
0004h
0005h
Inst(0004h)
Inst(0005h)
Dummy cycle
Inst(0004h)
TOST = 1024TOSC (drawing not to scale). This delay applies to LP, XT and HS modes only.
GIE = '1' assumed. In this case after wake- up, the processor jumps to the interrupt routine. If GIE = '0', execution will continue in-line.
CLKOUT is not available in these osc modes, but shown here for timing reference.
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15.0
INSTRUCTION SET SUMMARY
Each PIC16CXXX instruction is a 14-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 PIC16CXXX instruction set summary in Table 15-2 lists byte-oriented, bitoriented, and literal and control operations. Table 151 shows the opcode field descriptions.
For byte-oriented instructions, 'f' represents a file register designator and 'd' represents a destination designator. The file register designator specifies which file
register is to be used by the instruction.
The destination designator specifies where the result of
the operation is to be placed. If 'd' is zero, the result is
placed in the W register. If 'd' is one, the result is placed
in the file register specified in the instruction.
All instructions are executed within one single instruction cycle, unless a conditional test is true or the program counter is changed as a result of an instruction.
In this case, the execution takes two instruction cycles
with the second cycle executed as a NOP. One instruction cycle consists of four oscillator periods. Thus, for
an oscillator frequency of 4 MHz, the normal instruction
execution time is 1 s. If a conditional test is true or the
program counter is changed as a result of an instruction, the instruction execution time is 2 s.
Table 15-2 lists the instructions recognized by the
MPASMTM assembler.
Figure 15-1 shows the general formats that the instructions can have.
Note:
To maintain upward compatibility with
future PIC16CXXX products, do not use
the OPTION and TRIS instructions.
For bit-oriented instructions, 'b' represents a bit field
designator which selects the number of the bit affected
by the operation, while 'f' represents the number of the
file in which the bit is located.
All examples use the following format to represent a
hexadecimal number:
For literal and control operations, 'k' represents an
eight or eleven bit constant or literal value.
where h signifies a hexadecimal digit.
TABLE 15-1:
Field
f
W
b
k
x
d
PC
TO
PD
0xhh
FIGURE 15-1:
OPCODE FIELD
DESCRIPTIONS
GENERAL FORMAT FOR
INSTRUCTIONS
Byte-oriented file register operations
13
8 7 6
OPCODE
d
f (FILE #)
Description
Register file address (0x00 to 0x7F)
Working register (accumulator)
Bit address within an 8-bit file register
Literal field, constant data or label
Don't care location (= 0 or 1)
The assembler will generate code with x = 0. It
is the recommended form of use for compatibility with all Microchip software tools.
Destination select; d = 0: store result in W,
d = 1: store result in file register f.
Default is d = 1
Program Counter
Time-out bit
Power-down bit
0
d = 0 for destination W
d = 1 for destination f
f = 7-bit file register address
Bit-oriented file register operations
13
10 9
7 6
OPCODE
b (BIT #)
f (FILE #)
0
b = 3-bit bit address
f = 7-bit file register address
Literal and control operations
General
13
8
7
OPCODE
The instruction set is highly orthogonal and is grouped
into three basic categories:
0
k (literal)
k = 8-bit immediate value
• Byte-oriented operations
• Bit-oriented operations
• Literal and control operations
CALL and GOTO instructions only
13
11
OPCODE
10
0
k (literal)
k = 11-bit immediate value
A description of each instruction is available in the PIC
Mid-Range Reference Manual, (DS33023).
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TABLE 15-2:
PIC16CXXX INSTRUCTION SET
Mnemonic,
Operands
14-Bit Opcode
Description
Cycles
MSb
Status
Notes
Affected
LSb
BYTE-ORIENTED FILE REGISTER OPERATIONS
ADDWF
ANDWF
CLRF
CLRW
COMF
DECF
DECFSZ
INCF
INCFSZ
IORWF
MOVF
MOVWF
NOP
RLF
RRF
SUBWF
SWAPF
XORWF
f, d
f, d
f
f, d
f, d
f, d
f, d
f, d
f, d
f, d
f
f, d
f, d
f, d
f, d
f, d
Add W and f
AND W with f
Clear f
Clear W
Complement f
Decrement f
Decrement f, Skip if 0
Increment f
Increment f, Skip if 0
Inclusive OR W with f
Move f
Move W to f
No Operation
Rotate Left f through Carry
Rotate Right f through Carry
Subtract W from f
Swap nibbles in f
Exclusive OR W with f
BCF
BSF
BTFSC
BTFSS
f, b
f, b
f, b
f, b
Bit Clear f
Bit Set f
Bit Test f, Skip if Clear
Bit Test f, Skip if Set
ADDLW
ANDLW
CALL
CLRWDT
GOTO
IORLW
MOVLW
RETFIE
RETLW
RETURN
SLEEP
SUBLW
XORLW
k
k
k
k
k
k
k
k
k
Add literal and W
AND literal with W
Call subroutine
Clear Watchdog Timer
Go to address
Inclusive OR literal with W
Move literal to W
Return from interrupt
Return with literal in W
Return from Subroutine
Go into standby mode
Subtract W from literal
Exclusive OR literal with W
1
1
1
1
1
1
1(2)
1
1(2)
1
1
1
1
1
1
1
1
1
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
0111
0101
0001
0001
1001
0011
1011
1010
1111
0100
1000
0000
0000
1101
1100
0010
1110
0110
dfff
dfff
lfff
0000
dfff
dfff
dfff
dfff
dfff
dfff
dfff
lfff
0xx0
dfff
dfff
dfff
dfff
dfff
ffff
ffff
ffff
0011
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
0000
ffff
ffff
ffff
ffff
ffff
bfff
bfff
bfff
bfff
ffff
ffff
ffff
ffff
kkkk
kkkk
kkkk
0110
kkkk
kkkk
kkkk
0000
kkkk
0000
0110
kkkk
kkkk
kkkk
kkkk
kkkk
0100
kkkk
kkkk
kkkk
1001
kkkk
1000
0011
kkkk
kkkk
C,DC,Z
Z
Z
Z
Z
Z
Z
Z
Z
C
C
C,DC,Z
Z
1,2
1,2
2
1,2
1,2
1,2,3
1,2
1,2,3
1,2
1,2
1,2
1,2
1,2
1,2
1,2
BIT-ORIENTED FILE REGISTER OPERATIONS
1
1
1 (2)
1 (2)
01
01
01
01
00bb
01bb
10bb
11bb
1,2
1,2
3
3
LITERAL AND CONTROL OPERATIONS
1
1
2
1
2
1
1
2
2
2
1
1
1
11
11
10
00
10
11
11
00
11
00
00
11
11
111x
1001
0kkk
0000
1kkk
1000
00xx
0000
01xx
0000
0000
110x
1010
C,DC,Z
Z
TO,PD
Z
TO,PD
C,DC,Z
Z
Note 1: When an I/O register is modified as a function of itself ( e.g., MOVF PORTB, 1), the value used will be that
value present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and
is driven low by an external device, the data will be written back with a '0'.
2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be
cleared if assigned to the Timer0 Module.
3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The
second cycle is executed as a NOP.
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15.1
Instruction Descriptions
ADDLW
Add Literal and W
ANDWF
AND W with f
Syntax:
[label] ADDLW
Syntax:
[label] ANDWF
Operands:
0  k  255
Operands:
0  f  127
d 
(W) .AND. (f)  (destination)
k
f,d
Operation:
(W) + k  (W)
Status Affected:
C, DC, Z
Operation:
The contents of the W register
are added to the eight bit literal 'k'
and the result is placed in the W
register.
Status Affected:
Z
Description:
AND the W register with register
'f'. If 'd' is 0, the result is stored in
the W register. If 'd' is 1, the result
is stored back in register 'f'.
ADDWF
Add W and f
BCF
Bit Clear f
Syntax:
[label] ADDWF
Syntax:
[label] BCF
Operands:
0  f  127
d 
Operands:
0  f  127
0b7
Operation:
(W) + (f)  (destination)
Operation:
0  (f<b>)
Status Affected:
C, DC, Z
Status Affected:
None
Description:
Add the contents of the W register
with register 'f'. If 'd' is 0, the result
is stored in the W register. If 'd' is
1, the result is stored back in register 'f'.
Description:
Bit 'b' in register 'f' is cleared.
ANDLW
AND Literal with W
BSF
Bit Set f
Syntax:
[label] ANDLW
Syntax:
[label] BSF
Operands:
0  k  255
Operands:
Operation:
(W) .AND. (k)  (W)
0  f  127
0b7
Status Affected:
Z
Operation:
1  (f<b>)
The contents of W register are
AND’ed with the eight bit literal
'k'. The result is placed in the W
register.
Status Affected:
None
Description:
Bit 'b' in register 'f' is set.
Description:
Description:
 2001-2013 Microchip Technology Inc.
f,d
k
f,b
f,b
BTFSS
Bit Test f, Skip if Set
Syntax:
[label] BTFSS f,b
Operands:
0  f  127
0b<7
Operation:
skip if (f<b>) = 1
Status Affected:
None
Description:
If bit 'b' in register 'f' is '0', the next
instruction is executed.
If bit 'b' is '1', then the next instruction is discarded and a NOP is executed instead, making this a 2TCY
instruction.
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BTFSC
Bit Test, Skip if Clear
CLRWDT
Clear Watchdog Timer
Syntax:
[label] BTFSC f,b
Syntax:
[ label ] CLRWDT
Operands:
0  f  127
0b7
Operands:
None
Operation:
00h  WDT
0  WDT prescaler,
1  TO
1  PD
Status Affected:
TO, PD
Description:
CLRWDT instruction resets the
Watchdog Timer. It also resets the
prescaler of the WDT. Status bits
TO and PD are set.
Operation:
skip if (f<b>) = 0
Status Affected:
None
Description:
If bit 'b' in register 'f' is '1', the next
instruction is executed.
If bit 'b', in register 'f', is '0', the
next instruction is discarded, and
a NOP is executed instead, making
this a 2TCY instruction.
CALL
Call Subroutine
COMF
Complement f
Syntax:
[ label ] CALL k
Syntax:
[ label ] COMF
Operands:
0  k  2047
Operands:
Operation:
(PC)+ 1 TOS,
k  PC<10:0>,
(PCLATH<4:3>)  PC<12:11>
0  f  127
d  [0,1]
Operation:
(f)  (destination)
Status Affected:
Z
Status Affected:
None
Description:
Description:
Call Subroutine. First, return
address (PC+1) is pushed onto
the stack. The eleven-bit immediate address is loaded into PC bits
<10:0>. The upper bits of the PC
are loaded from PCLATH. CALL is
a two-cycle instruction.
The contents of register 'f' are
complemented. If 'd' is 0, the
result is stored in W. If 'd' is 1, the
result is stored back in register 'f'.
CLRF
Clear f
Syntax:
[label] CLRF
Operands:
Operation:
f,d
DECF
Decrement f
Syntax:
[label] DECF f,d
0  f  127
Operands:
00h  (f)
1Z
0  f  127
d  [0,1]
Operation:
(f) - 1  (destination)
Status Affected:
Z
Status Affected:
Z
Description:
The contents of register 'f' are
cleared and the Z bit is set.
Description:
Decrement register 'f'. If 'd' is 0,
the result is stored in the W register. If 'd' is 1, the result is stored
back in register 'f'.
CLRW
Clear W
Syntax:
[ label ] CLRW
Operands:
None
Operation:
00h  (W)
1Z
f
Status Affected:
Z
Description:
W register is cleared. Zero bit (Z)
is set.
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DECFSZ
Decrement f, Skip if 0
INCFSZ
Increment f, Skip if 0
Syntax:
[ label ] DECFSZ f,d
Syntax:
[ label ]
Operands:
0  f  127
d  [0,1]
Operands:
0  f  127
d  [0,1]
Operation:
(f) - 1  (destination);
skip if result = 0
Operation:
(f) + 1  (destination),
skip if result = 0
Status Affected:
None
Status Affected:
None
Description:
The contents of register 'f' are
decremented. If 'd' is 0, the result
is placed in the W register. If 'd' is
1, the result is placed back in register 'f'.
If the result is 1, the next instruction is executed. If the result is 0,
then a NOP is executed instead,
making it a 2TCY instruction.
Description:
The contents of register 'f' are
incremented. If 'd' is 0, the result is
placed in the W register. If 'd' is 1,
the result is placed back in register 'f'.
If the result is 1, the next instruction is executed. If the result is 0,
a NOP is executed instead, making
it a 2TCY instruction.
GOTO
Unconditional Branch
IORLW
Inclusive OR Literal with W
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0  k  2047
Operands:
0  k  255
Operation:
k  PC<10:0>
PCLATH<4:3>  PC<12:11>
Operation:
(W) .OR. k  (W)
Status Affected:
Z
Status Affected:
None
Description:
Description:
GOTO is an unconditional branch.
The eleven-bit immediate value is
loaded into PC bits <10:0>. The
upper bits of PC are loaded from
PCLATH<4:3>. GOTO is a twocycle instruction.
The contents of the W register are
OR’ed with the eight-bit literal 'k'.
The result is placed in the W register.
GOTO k
INCFSZ f,d
IORLW k
INCF
Increment f
IORWF
Inclusive OR W with f
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0  f  127
d  [0,1]
Operands:
0  f  127
d  [0,1]
Operation:
(f) + 1  (destination)
Operation:
(W) .OR. (f)  (destination)
Status Affected:
Z
Status Affected:
Z
Description:
The contents of register 'f' are
incremented. If 'd' is 0, the result
is placed in the W register. If 'd' is
1, the result is placed back in register 'f'.
Description:
Inclusive OR the W register with
register 'f'. If 'd' is 0 the result is
placed in the W register. If 'd' is 1
the result is placed back in register 'f'.
INCF f,d
 2001-2013 Microchip Technology Inc.
Preliminary
IORWF
f,d
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MOVF
Move f
Syntax:
[ label ]
Operands:
0  f  127
d  [0,1]
Operation:
(f)  (destination)
MOVF f,d
RETLW
Return with Literal in W
Syntax:
[ label ]
Operands:
0  k  255
Operation:
k  (W);
TOS  PC
RETLW k
Status Affected:
Z
Status Affected:
None
Description:
The contents of register f are
moved to a destination dependant
upon the status of d. If d = 0, destination is W register. If d = 1, the
destination is file register f itself.
d = 1 is useful to test a file register,
since status flag Z is affected.
Description:
The W register is loaded with the
eight bit literal 'k'. The program
counter is loaded from the top of
the stack (the return address).
This is a two-cycle instruction.
MOVLW
Move Literal to W
RETURN
Return from Subroutine
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0  k  255
Operands:
None
Operation:
k  (W)
Operation:
TOS  PC
Status Affected:
None
Status Affected:
None
Description:
The eight-bit literal 'k' is loaded
into W register. The don’t cares
will assemble as 0’s.
Description:
Return from subroutine. The stack is
POPed and the top of the stack (TOS)
is loaded into the program counter.
This is a two-cycle instruction.
MOVWF
Move W to f
RLF
Rotate Left f through Carry
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0  f  127
Operands:
0  f  127
d  [0,1]
See description below
MOVLW k
MOVWF
f
RETURN
RLF
f,d
Operation:
(W)  (f)
Status Affected:
None
Operation:
Description:
Move data from W register to register 'f'.
Status Affected:
C
Description:
The contents of register 'f' are
rotated one bit to the left through
the Carry Flag. If 'd' is 0, the
result is placed in the W register.
If 'd' is 1, the result is stored back
in register 'f'.
NOP
No Operation
Syntax:
[ label ]
Operands:
None
Operation:
No operation
NOP
C
Status Affected:
None
Description:
No operation.
RETFIE
Return from Interrupt
Syntax:
[ label ]
Operands:
None
Operation:
TOS  PC,
1  GIE
Status Affected:
None
DS41171B-page 138
Register f
RETFIE
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RRF
Rotate Right f through Carry
SUBWF
Subtract W from f
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0  f  127
d  [0,1]
Operands:
0 f 127
d  [0,1]
Operation:
See description below
Operation:
(f) - (W) destination)
Status Affected:
C
Status Affected: C, DC, Z
Description:
The contents of register 'f' are
rotated one bit to the right through
the Carry Flag. If 'd' is 0, the result
is placed in the W register. If 'd' is
1, the result is placed back in register 'f'.
Description:
RRF f,d
C
Subtract (2’s complement method)
W register from register 'f'. If 'd' is 0,
the result is stored in the W register. If 'd' is 1, the result is stored
back in register 'f'.
Register f
SLEEP
Syntax:
[ label ]
Operands:
None
Operation:
00h  WDT,
0  WDT prescaler,
1  TO,
0  PD
Status Affected:
TO, PD
Description:
The power-down status bit, PD is
cleared. Time-out status bit, TO
is set. Watchdog Timer and its
prescaler are cleared.
The processor is put into SLEEP
mode with the oscillator stopped.
SLEEP
SUBLW
Subtract W from Literal
Syntax:
[ label ]
Operands:
0 k 255
Operation:
k - (W) W)
SUBLW k
Status Affected: C, DC, Z
Description:
SUBWF f,d
The W register is subtracted (2’s
complement method) from the
eight-bit literal 'k'. The result is
placed in the W register.
 2001-2013 Microchip Technology Inc.
SWAPF
Swap Nibbles in f
Syntax:
[ label ] SWAPF f,d
Operands:
0  f  127
d  [0,1]
Operation:
(f<3:0>)  (destination<7:4>),
(f<7:4>)  (destination<3:0>)
Status Affected:
None
Description:
The upper and lower nibbles of
register 'f' are exchanged. If 'd' is
0, the result is placed in W register. If 'd' is 1, the result is placed in
register 'f'.
XORLW
Exclusive OR Literal with W
Syntax:
[label]
Operands:
0 k 255
Operation:
(W) .XOR. k W)
Status Affected:
Z
Description:
The contents of the W register
are XOR’ed with the eight-bit literal 'k'. The result is placed in
the W register.
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XORWF
Exclusive OR W with f
Syntax:
[label]
Operands:
0  f  127
d  [0,1]
Operation:
(W) .XOR. (f) destination)
XORWF
f,d
Status Affected:
Z
Description:
Exclusive OR the contents of the
W register with register 'f'. If 'd' is
0, the result is stored in the W
register. If 'd' is 1, the result is
stored back in register 'f'.
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16.0
DEVELOPMENT SUPPORT
The MPLAB IDE allows you to:
The PIC® microcontrollers are supported with a full
range of hardware and software development tools:
• Integrated Development Environment
- MPLAB® IDE Software
• Assemblers/Compilers/Linkers
- MPASMTM Assembler
- MPLAB C17 and MPLAB C18 C Compilers
- MPLINKTM Object Linker/
MPLIBTM Object Librarian
• Simulators
- MPLAB SIM Software Simulator
• Emulators
- MPLAB ICE 2000 In-Circuit Emulator
- ICEPIC™ In-Circuit Emulator
• In-Circuit Debugger
- MPLAB ICD
• Device Programmers
- PRO MATE® II Universal Device Programmer
- PICSTART® Plus Entry-Level Development
Programmer
• Low Cost Demonstration Boards
- PICDEMTM 1 Demonstration Board
- PICDEM 2 Demonstration Board
- PICDEM 3 Demonstration Board
- PICDEM 17 Demonstration Board
- KEELOQ® Demonstration Board
16.1
The ability to use MPLAB IDE with multiple debugging
tools allows users to easily switch from the costeffective simulator to a full-featured emulator with
minimal retraining.
16.2
The MPASM assembler has a command line interface
and a Windows shell. It can be used as a stand-alone
application on a Windows 3.x or greater system, or it
can be used through MPLAB IDE. 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, an absolute LST file that contains source lines and generated
machine code, and a COD file for debugging.
The MPASM assembler features include:
The MPLAB IDE software brings an ease of software
development previously unseen in the 8-bit microcontroller market. The MPLAB IDE is a Windows®-based
application that contains:
 2001-2013 Microchip Technology Inc.
MPASM Assembler
The MPASM assembler is a full-featured universal
macro assembler for all PIC MCUs.
MPLAB Integrated Development
Environment Software
• An interface to debugging tools
- simulator
- programmer (sold separately)
- emulator (sold separately)
- in-circuit debugger (sold separately)
• A full-featured editor
• A project manager
• Customizable toolbar and key mapping
• A status bar
• On-line help
• Edit your source files (either assembly or ‘C’)
• One touch assemble (or compile) and download
to PIC MCU emulator and simulator tools (automatically updates all project information)
• Debug using:
- source files
- absolute listing file
- machine code
• Integration into MPLAB IDE projects.
• User-defined macros to streamline assembly
code.
• Conditional assembly for multi-purpose source
files.
• Directives that allow complete control over the
assembly process.
16.3
MPLAB C17 and MPLAB C18
C Compilers
The MPLAB C17 and MPLAB C18 Code Development
Systems are complete ANSI ‘C’ compilers for
Microchip’s PIC17CXXX and PIC18CXXX family of
microcontrollers, respectively. These compilers provide
powerful integration capabilities and ease of use not
found with other compilers.
For easier source level debugging, the compilers provide symbol information that is compatible with the
MPLAB IDE memory display.
Preliminary
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16.4
MPLINK Object Linker/
MPLIB Object Librarian
16.6
The MPLINK object linker combines relocatable
objects created by the MPASM assembler and the
MPLAB C17 and MPLAB C18 C compilers. It can also
link relocatable objects from pre-compiled libraries,
using directives from a linker script.
The MPLIB object librarian is a librarian for precompiled code to be used with the MPLINK object
linker. When a routine from a library is called from
another 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 MPLIB object librarian manages the
creation and modification of library files.
The MPLINK object linker features include:
• Integration with MPASM assembler and MPLAB
C17 and MPLAB C18 C compilers.
• Allows all memory areas to be defined as sections
to provide link-time flexibility.
The MPLIB object librarian features include:
• Easier linking because single libraries can be
included instead of many smaller files.
• Helps keep code maintainable by grouping
related modules together.
• Allows libraries to be created and modules to be
added, listed, replaced, deleted or extracted.
16.5
The MPLAB ICE universal in-circuit emulator is intended
to provide the product development engineer with a
complete microcontroller design tool set for PIC microcontrollers (MCUs). Software control of the MPLAB ICE
in-circuit emulator is provided by the MPLAB Integrated
Development Environment (IDE), which allows editing,
building, downloading and source debugging from a
single environment.
The MPLAB ICE 2000 is a full-featured emulator system with enhanced trace, trigger and data monitoring
features. Interchangeable processor modules allow the
system to be easily reconfigured for emulation of different processors. The universal architecture of the
MPLAB ICE in-circuit emulator allows expansion to
support new PIC microcontrollers.
The MPLAB ICE in-circuit emulator system has been
designed as a real-time emulation system, with
advanced features that are generally found on more
expensive development tools. The PC platform and
Microsoft® Windows environment were chosen to best
make these features available to you, the end user.
16.7
MPLAB SIM Software Simulator
The MPLAB SIM software simulator allows code development in a PC-hosted environment by simulating the
PIC series microcontrollers on an instruction level. On
any given instruction, the data areas can be examined
or modified and stimuli can be applied from a file, or
user-defined key press, to any of the pins. The execution can be performed in single step, execute until
break, or trace mode.
MPLAB ICE High Performance
Universal In-Circuit Emulator with
MPLAB IDE
ICEPIC In-Circuit Emulator
The ICEPIC low cost, in-circuit emulator is a solution
for the Microchip Technology PIC16C5X, PIC16C6X,
PIC16C7X and PIC16CXXX families of 8-bit OneTime-Programmable (OTP) microcontrollers. The modular system can support different subsets of PIC16C5X
or PIC16CXXX products through the use of interchangeable personality modules, or daughter boards.
The emulator is capable of emulating without target
application circuitry being present.
The MPLAB SIM simulator fully supports symbolic debugging using the MPLAB C17 and the MPLAB C18 C compilers and the MPASM assembler. The software simulator
offers the flexibility to develop and debug code outside of
the laboratory environment, making it an excellent multiproject software development tool.
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16.8
MPLAB ICD In-Circuit Debugger
Microchip's In-Circuit Debugger, MPLAB ICD, is a powerful, low cost, run-time development tool. This tool is
based on the FLASH PIC MCUs and can be used to
develop for this and other PIC microcontrollers. The
MPLAB ICD utilizes the in-circuit debugging capability
built into the FLASH devices. This feature, along with
Microchip's In-Circuit Serial ProgrammingTM protocol,
offers cost-effective in-circuit FLASH debugging from
the graphical user interface of the MPLAB Integrated
Development Environment. This enables a designer to
develop and debug source code by watching variables,
single-stepping and setting break points. Running at
full speed enables testing hardware in real-time.
16.9
PRO MATE II Universal Device
Programmer
The PRO MATE II universal device programmer is a
full-featured programmer, capable of operating in
stand-alone mode, as well as PC-hosted mode. The
PRO MATE II device programmer is CE compliant.
The PRO MATE II device programmer has programmable VDD and VPP supplies, which allow it to verify
programmed memory at VDD min and VDD max for maximum reliability. It has an LCD display for instructions
and error messages, keys to enter commands and a
modular detachable socket assembly to support various
package types. In stand-alone mode, the PRO MATE II
device programmer can read, verify, or program PIC
devices. It can also set code protection in this mode.
16.10 PICSTART Plus Entry Level
Development Programmer
The PICSTART Plus development programmer is an
easy-to-use, low cost, prototype programmer. It connects to the PC via a COM (RS-232) port. MPLAB
Integrated Development Environment software makes
using the programmer simple and efficient.
The PICSTART Plus development programmer supports all PIC devices with up to 40 pins. Larger pin
count devices, such as the PIC16C92X and
PIC17C76X, may be supported with an adapter socket.
The PICSTART Plus development programmer is CE
compliant.
 2001-2013 Microchip Technology Inc.
16.11 PICDEM 1 Low Cost PIC MCU
Demonstration Board
The PICDEM 1 demonstration board is a simple board
which demonstrates the capabilities of several of
Microchip’s microcontrollers. The microcontrollers supported are: PIC16C5X (PIC16C54 to PIC16C58A),
PIC16C61, PIC16C62X, PIC16C71, PIC16C8X,
PIC17C42, PIC17C43 and PIC17C44. All necessary
hardware and software is included to run basic demo
programs. The user can program the sample microcontrollers provided with the PICDEM 1 demonstration
board on a PRO MATE II device programmer, or a
PICSTART Plus development programmer, and easily
test firmware. The user can also connect the
PICDEM 1 demonstration board to the MPLAB ICE incircuit emulator and download the firmware to the emulator for testing. A prototype area is available for the
user to build some additional hardware and connect it
to the microcontroller socket(s). Some of the features
include an RS-232 interface, a potentiometer for simulated analog input, push button switches and eight
LEDs connected to PORTB.
16.12 PICDEM 2 Low Cost PIC16CXX
Demonstration Board
The PICDEM 2 demonstration board is a simple demonstration board that supports the PIC16C62,
PIC16C64, PIC16C65, PIC16C73 and PIC16C74
microcontrollers. All the necessary hardware and software is included to run the basic demonstration programs. The user can program the sample
microcontrollers provided with the PICDEM 2 demonstration board on a PRO MATE II device programmer,
or a PICSTART Plus development programmer, and
easily test firmware. The MPLAB ICE in-circuit emulator may also be used with the PICDEM 2 demonstration
board to test firmware. A prototype area has been provided to the user for adding additional hardware and
connecting it to the microcontroller socket(s). Some of
the features include a RS-232 interface, push button
switches, a potentiometer for simulated analog input, a
serial EEPROM to demonstrate usage of the I2CTM bus
and separate headers for connection to an LCD
module and a keypad.
Preliminary
DS41171B-page 143
PIC16C781.book Page 144 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
16.13 PICDEM 3 Low Cost PIC16CXXX
Demonstration Board
The PICDEM 3 demonstration board is a simple demonstration board that supports the PIC16C923 and
PIC16C924 in the PLCC package. It will also support
future 44-pin PLCC microcontrollers with an LCD Module. All the necessary hardware and software is
included to run the basic demonstration programs. The
user can program the sample microcontrollers provided with the PICDEM 3 demonstration board on a
PRO MATE II device programmer, or a PICSTART Plus
development programmer with an adapter socket, and
easily test firmware. The MPLAB ICE in-circuit emulator may also be used with the PICDEM 3 demonstration
board to test firmware. A prototype area has been provided to the user for adding hardware and connecting it
to the microcontroller socket(s). Some of the features
include a RS-232 interface, push button switches, a
potentiometer for simulated analog input, a thermistor
and separate headers for connection to an external
LCD module and a keypad. Also provided on the
PICDEM 3 demonstration board is a LCD panel, with 4
commons and 12 segments, that is capable of displaying time, temperature and day of the week. The
PICDEM 3 demonstration board provides an additional
RS-232 interface and Windows software for showing
the demultiplexed LCD signals on a PC. A simple serial
interface allows the user to construct a hardware
demultiplexer for the LCD signals.
DS41171B-page 144
16.14 PICDEM 17 Demonstration Board
The PICDEM 17 demonstration board is an evaluation
board that demonstrates the capabilities of several
Microchip microcontrollers, including PIC17C752,
PIC17C756A, PIC17C762 and PIC17C766. All necessary hardware is included to run basic demo programs,
which are supplied on a 3.5-inch disk. A programmed
sample is included and the user may erase it and
program it with the other sample programs using the
PRO MATE II device programmer, or the PICSTART
Plus development programmer, and easily debug and
test the sample code. In addition, the PICDEM 17 demonstration board supports downloading of programs to
and executing out of external FLASH memory on board.
The PICDEM 17 demonstration board is also usable
with the MPLAB ICE in-circuit emulator, or the
PICMASTER emulator and all of the sample programs
can be run and modified using either emulator. Additionally, a generous prototype area is available for user
hardware.
16.15 KEELOQ Evaluation and
Programming Tools
KEELOQ evaluation and programming tools support
Microchip’s HCS Secure Data Products. The HCS evaluation kit includes a LCD display to show changing
codes, a decoder to decode transmissions and a programming interface to program test transmitters.
Preliminary
 2001-2013 Microchip Technology Inc.
Software Tools
Programmers Debugger Emulators
PIC12CXXX
PIC14000
PIC16C5X
PIC16C6X


PIC16CXXX


PIC16F62X


PIC16C7X


PIC16C7XX


PIC16C8X


PIC16F8XX




PIC16C9XX

 2001-2013 Microchip Technology Inc.
Preliminary
3 Demonstration
2 Demonstration


**


†
†










































13.56 MHz Anticollision
microIDTM Developer’s Kit

MCP2510
* Contact the Microchip Technology Inc. web site at www.microchip.com for information on how to use the MPLAB® ICD In-Circuit Debugger (DV164001) with PIC16C62, 63, 64, 65, 72, 73, 74, 76, 77.
** Contact Microchip Technology Inc. for availability date.
†
Development tool is available on select devices.
MCP2510 CAN Developer’s Kit


125 kHz Anticollision microIDTM
Developer’s Kit

125 kHz microIDTM
Developer’s Kit
MCRFXXX
microIDTM Programmer’s Kit

†



*






**
**
PIC18FXXX

24CXX/
25CXX/
93CXX
KEELOQ® Transponder Kit








HCSXXX
KEELOQ® Evaluation Kit
PICDEMTM 17 Demonstration
Board
PICDEMTM 14A Demonstration
Board
Board
PICDEMTM
Board
PICDEMTM
PICDEMTM 1 Demonstration
Board


PRO MATE® II
Universal Device Programmer






PICSTART® Plus Entry Level
Development Programmer


*

ICEPICTM In-Circuit Emulator

MPLAB® ICD In-Circuit
Debugger

MPLAB® ICE In-Circuit Emulator





PIC17C4X



PIC17C7XX
MPLAB® C18 C Compiler


PIC18CXX2
MPASMTM Assembler/
MPLINKTM Object Linker
MPLAB® C17 C Compiler
TABLE 16-1:
Demo Boards and Eval Kits
MPLAB® Integrated
Development Environment
PIC16C781.book Page 145 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
DEVELOPMENT TOOLS FROM MICROCHIP
DS41171B-page 145
PIC16C781.book Page 146 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
NOTES:
DS41171B-page 146
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 147 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
17.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings †
Ambient temperature under bias....................................................................................................... -55°C to +125°C
Storage temperature ......................................................................................................................... -65°C to +150°C
Voltage on any pin with respect to VSS (except VDD, MCLR and RA4) ................................... -0.3V to (VDD + 0.3 V)
Voltage on VDD with respect to VSS .......................................................................................................-0.3 to +7.5 V
Maximum voltage between AVDD and VDD pins............................................................................................... ± 0.3 V
Maximum voltage between AVSS and VSS pins ............................................................................................... ± 0.3 V
Voltage on MCLR with respect to VSS................................................................................................ -0.3 V to +8.5 V
Voltage on RA4 with respect to Vss ...................................................................................................0.3 V to +10.5 V
Total power dissipation(1) (PDIP, SOIC)............................................................................................................. 1.0 W
Total power dissipation(1) (SSOP) .................................................................................................................... 0.65 W
Maximum current out of VSS pin ..................................................................................................................... 300 mA
Maximum current into VDD pin ........................................................................................................................ 250 mA
Input clamp current, IIK (VI < 0 or VI > VDD .................................................................................................... ± 20 mA
Output clamp current, IOK (VO < 0 or VO > VDD ............................................................................................. ± 20 mA
Maximum output current sunk by any I/O pin.................................................................................................... 25 mA
Maximum output current sourced by any I/O pin .............................................................................................. 25 mA
Maximum current sunk by PORTA and PORTB (combined)........................................................................... 200 mA
Maximum current sourced by PORTA and PORTB (combined....................................................................... 200 mA
Note 1: Power dissipation is calculated as follows: PDIS = VDD x {IDD -  IOH} +  {(VDD - VOH) x IOH} + (VOL x IOL).
† NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. This is a stress rating only and functional operation of the device at those or any other conditions above those
indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for
extended periods may affect device reliability.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 147
PIC16C781.book Page 148 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
PIC16C781/782 VOLTAGE-FREQUENCY GRAPH, -40C  TA  +85C
FIGURE 17-1:
6.0
5.5
5.0
VDD
(Volts)
4.5
4.0
3.5
3.0
2.5
0
4
10
Frequency (MHz)
20
25
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
PIC16LC781/782 VOLTAGE-FREQUENCY GRAPH, -40C  TA  +85C
FIGURE 17-2:
5.5
4.54.0
VDD
(Volts)
2.7
0
4
10
Frequency (MHz)
20
25
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
DS41171B-page 148
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 149 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
17.1
DC Characteristics: Power Supply
TABLE 17-1:
DC CHARACTERISTICS: PIC16C781/782, DSTEMP (INDUSTRIAL)
Standard Operating Conditions (unless otherwise stated)
Operating temperature-40°C  TA  +85°C for industrial
DC CHARACTERISTICS
Param
No.
Sym
Characteristic
Min
Typ†
Max
Units
Conditions
D001
VDD
Supply Voltage
4.0
4.5
—
—
5.5
5.5
V
—
XT, EC, RC, INTRC Oscillator
HS Oscillator
D001A
VDD
Supply Voltage (DSTEMP)
2.7
4.5
—
—
5.5
5.5
V
V
XT, EC, RC, INTRC Oscillator
HS Oscillator
D002*
VDR
RAM Data Retention
Voltage(1)
—
1.5
—
V
D003
VPOR
VDD Start Voltage to
ensure internal Power-on Reset signal
—
TBD
—
V
See section on Power-on Reset for
details
D004*
SVDD
VDD Rise Rate to ensure internal
Power-on Reset signal
0.05
—
—
V/ms
See section on Power-on Reset for
details. PWRT enabled
D010
IDD
Supply Current(2)
—
TBD
TBD
mA
—
TBD
TBD
mA
—
TBD
TBD
mA
—
TBD
TBD
mA
D020
D020A
FOSC = 20 MHz, VDD = 5.5V*
HS Oscillator
FOSC = 20 MHz, VDD = 4.5V
HS Oscillator
FOSC = 4 MHz, VDD = 4.0V*
XT, RC w/CLKOUT
FOSC = 32 kHz, VDD = 4.0V
LP Oscillator
IPD
Power-down Current(3)
—
—
TBD
1.5
TBD
19
A
A
VDD = 5.5V
VDD = 4.0V
IOPA
Operational Amplifier
—
TBD
TBD
mA
TBD
TBD
mA
VDD = 5.0V,
GBWP = 0
VDD = 5.0V,
GBWP = 1
—
TBD
TBD
mA
—
TBD
TBD
mA
IVC*
Voltage Comparators C1 and C2
VDD = 5.0V, VID>100 mV
C1SP = 0
VDD = 5.0 , VID>100 mV
C1SP = 1
IADC*
Digital to Analog Converter (DAC)
—
TBD
TBD
mA
D021
IWDT*
Watchdog Timer
—
TBD
TBD
mA
VDD = 4.0V
D026
IAD*
Analog-to-Digital Converter (ADC)
—
TBD
TBD
mA
VDD = 5.5V, ADC not converting
1A
IPLVD*
Programmable Low Voltage Detect
TBD
TBD
mA
VDD = 4.0V
IPBOR*
Programmable Brown-out Reset
TBD
TBD
mA
VDD = 5.0V
FOSC
LP Oscillator, Operating Freq.
INTRC Oscillator Operating Freq.
—
4
37
—
—
200
—
—
4
20
kHz
MHz
kHz
MHz
MHz
All temperatures
All temperatures, OSCF = 1
All temperatures, OSCF = 0
All temperatures
All temperatures
XT Oscillator Operating Freq.
HS Oscillator Operating Freq.
*
†
Note 1:
2:
3:
VDD = 5.0V
9
—
—
0
0
These parameters are characterized but not tested.
Data in "Typ" column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
This is the limit to which VDD can be lowered without losing RAM data.
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.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins configured as inputs, pulled to VDD
MCLR = VDD; WDT enabled/disabled as specified.
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 configured as iputs and tied to VDD or VSS.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 149
PIC16C781.book Page 150 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
17.2
DC Characteristics: Input/Output Pins
TABLE 17-2:
DC CHARACTERISTICS: PIC16C781/782, DSTEMP (INDUSTRIAL)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA  +85°C for industrial and
Operating voltage VDD range as described in DC spec Section 17-1
DC CHARACTERISTICS
Param
No.
Sym
Min
Typ†
Max
Units
VSS
VSS
VSS
VSS
—
—
—
—
0.15VDD
0.8V
0.2VDD
0.2VDD
V
V
V
V
VSS
—
0.3 VD
V
—
—
—
VDD
VDD
V
V
4.5V  VDD  5.5V
For entire VDD range
—
—
VDD
VDD
V
V
For entire VDD range
0.7VDD
50
—
250
VDD
400
V
µA
Input Leakage Current(1,2)
I/O ports (with digital functions)
—
—
±1
µA
D060A IIL
I/O ports (with analog functions)
—
—
±100
nA
D061
D063
RA5/MCLR/VPP
OSC1
—
—
—
—
±5
±5
µA
µA
Output Low Voltage
I/O ports (Includes CLKOUT)
Output High Voltage
—
—
0.6
V
VIL
D030
D030A
D031
D032
Characteristic
Input Low Voltage
I/O ports:
with TTL buffer
with Schmitt Trigger buffer
D033
VIH
D040
D040A
D041
D042
MCLR
OSC1 (in XT, HS, LP and EC)
Input High Voltage
I/O ports:
with TTL buffer
with Schmitt Trigger buffer
D042A
D070
IPURB
D060
IIL
D080
VOL
MCLR
OSC1 (XT, HS, LP and EC)
PORTB Weak Pull-up Current
Per Pin
2.0
(0.25VDD
+ 0.8V)
0.8VDD
0.8VDD
Conditions
For entire VDD range
4.5V  VDD  5.5V
For entire VDD range
VDD = 5V, VPIN = VSS
Vss VPIN  VDD, Pin at
hi-impedance
Vss  VPIN  VDD, Pin at
hi-impedance
Vss  VPIN  VDD
Vss  VPIN  VDD, XT, HS, LP
and EC osc configuration
IOL = 8.5 mA, VDD = 4.5V
D090
VOH
VDD - 0.7
—
—
V
IOH = -3.0 mA, VDD = 4.5V
D150*
VOD
—
—
10.5
V
RA4 pin
—
—
15
pF
In XT, HS and LP modes when
external clock is used to drive
OSC1.
D100
I/O ports(2) (Includes CLKOUT)
Open Drain High Voltage
Capacitive Loading Specs on
Output Pins*
Cosc2 OSC2 pin
D101
CIO
*
†
Note 1:
2:
All I/O pins and OSC2 (in RC
—
—
50
pF
mode)
These parameters are characterized but not tested.
Data in “Typ” column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only
and are not tested.
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.
Negative current is defined as current sourced by the pin.
DS41171B-page 150
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 151 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
17.3
17.3.1
AC Characteristics: PIC16C781/782 (Industrial)
TIMING PARAMETER SYMBOLOGY
The timing parameter symbols have been created following one of the following formats:
1. TppS2ppS
2. TppS
T
F
Frequency
Lowercase letters (pp) and their meanings:
pp
T
Time
osc
ck
CLKOUT
dt
Data in
io
I/O port
mc
MCLR
Uppercase letters and their meanings:
OSC1
t0
t1
T0CKI
T1CKI
P
R
V
Z
High
Low
Period
Rise
Valid
Hi-impedance
High
Low
S
F
H
I
L
Fall
High
Invalid (Hi-impedance)
Low
FIGURE 17-3:
LOAD CONDITIONS
Load condition 2
Load condition 1
VDD/2
RL
CL
Pin
CL
Pin
VSS
VSS
RL = 464
CL = 50 pF
15 pF
for all pins except OSC2
for OSC2 output
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 151
PIC16C781.book Page 152 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
17.3.2
TIMING DIAGRAMS AND SPECIFICATIONS
FIGURE 17-4:
CLKOUT AND I/O TIMING
Q1
Q4
Q2
Q3
OSC1
11
10
CLKOUT
13
19
14
12
18
16
I/O Pin
(input)
15
17
I/O Pin
(output)
new value
old value
20, 21
Note 1: Refer to Figure 17-3 for load conditions.
TABLE 17-3:
Parameter
No.
CLKOUT AND I/O TIMING REQUIREMENTS
Sym
Characteristic
Min
Typ†
Max
Units Conditions
10*
TOSH2CKL
OSC1 to CLKOUT
—
75
200
ns
11*
TOSH2CKH
OSC1 to CLKOUT
—
75
200
ns
(Note 1)
(Note 1)
12*
TCKR
CLKOUT rise time
—
35
100
ns
(Note 1)
13*
TCkF
CLKOUT fall time
—
35
100
ns
(Note 1)
14*
TCKL2IOV
CLKOUT  to Port out valid
—
—
0.5TCY + 20
ns
(Note 1)
15*
TIOV2CKH
Port in valid before CLKOUT 
0.25TCY + 25
—
—
ns
(Note 1)
16*
TCKH2IOl
Port in hold after CLKOUT 
0
—
—
ns
(Note 1)
17*
TOSH2IOV
OSC1 (Q1 cycle) to
Port out valid
—
50
150
ns
18*
TOSH2IOl
OSC1 (Q2 cycle) to
Port input invalid (I/O
in hold time)
PIC16C781/782
100
—
—
ns
PIC16LC781/782
200
—
—
ns
19*
TIOV2OSH
Port input valid to OSC1 (I/O in setup time)
0
—
—
ns
20*
TIOR
Port output rise time
PIC16C781/782
—
10
25
ns
PIC16LC781/782
—
—
60
ns
21*
TIOF
Port output fall time
PIC16C781/782
—
10
25
ns
—
—
60
ns
22††*
TINP
INT pin high or low time
TCY
—
—
ns
23††*
TRBP
RB7:RB0 change INT high or low time
TCY
—
—
ns
PIC16LC781/782
*
†
These parameters are characterized but not tested.
Data in "Typ" column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
†† These parameters are asynchronous events not related to any internal clock edges.
Note 1: Measurements are taken in RC mode where CLKOUT output is 4 x TOSC.
DS41171B-page 152
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 153 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
FIGURE 17-5:
EXTERNAL CLOCK TIMING
Q4
Q1
Q2
Q3
Q4
Q1
OSC1
1
3
3
4
4
2
CLKOUT
TABLE 17-4:
Parameter
No.
1A
EXTERNAL CLOCK TIMING REQUIREMENTS
Sym
FOSC
1
TOSC
Characteristic
Min
Typ†
Max
Units
External CLKIN Frequency(1)
DC
DC
DC
DC
—
—
—
—
4
20
20
200
MHz
MHz
MHz
kHz
Oscillator Frequency(1)
0.1
4
5
—
—
—
4
20
200
MHz XT osc mode
MHz HS osc mode
kHz LP osc mode
External CLKIN Period(1)
250
50
50
5
—
—
—
—
—
—
—
—
ns
ns
ns
s
XT and RC osc mode
EC osc mode
HS osc mode
LP osc mode
Oscillator Period(1)
250
50
5
—
—
—
10,000
250
—
ns
ns
s
XT osc mode
HS osc mode
LP osc mode
200
100
2.5
15
TCY
—
—
—
DC
—
—
—
ns
ns
s
ns
—
—
—
—
—
—
25
50
15
ns
ns
ns
TCY = 4/FOSC
XT oscillator
LP oscillator
HS oscillator
EC oscillator
XT oscillator
LP oscillator
HS oscillator
EC oscillator
2
TCY
3*
TOSL,
TOSH
Instruction Cycle Time(1)
External Clock in (OSC1) High or
Low Time
4*
TOSR,
TOSF
External Clock in (OSC1) Rise or
Fall Time
Conditions
XT osc mode
EC osc mode
HS osc mode
LP osc mode
*
†
These parameters are characterized but not tested.
Data in “Typ” column is at 5V, 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/CLKIN pin.
When an external clock input is used, the "Max." cycle time limit is "DC" (no clock) for all devices.
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
TABLE 17-5:
INTERNAL RC OSCILLATOR CALIBRATED FREQUENCIES PIC16C781/782,
DSTEMP
Standard Operating Conditions (unless otherwise specified)
Operating Temperature –40×C  TA  +85C (industrial)
Operating Voltage VDD range is described in Section 17-1.
AC Characteristics
Parameter
No.
Min
Typ(1)
Internal Calibrated RC Frequency
3.65
Internal Calibrated RC Frequency
3.55*
Sym
Characteristic
Max
Units
Conditions
4.00
4.28
MHz VDD = 5.0V
4.00
4.31*
MHz VDD = 2.5V
* These parameters are characterized but not tested.
Note 1: Data in the Typical (“Typ”) column is at 5V, 25C unless otherwise stated. These parameters are for design
guidance only and are not tested.
FIGURE 17-6:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP
TIMER TIMING
VDD
MCLR
30
Internal
POR
33
PWRT
Time-out
32
OSC
Time-out
Internal
RESET
Watchdog
Timer
Reset
31
34
34
I/O Pins
Note 1: Refer to Figure 17-3 for load conditions.
FIGURE 17-7:
VDD
BROWN-OUT RESET TIMING
BVDD
35
DS41171B-page 154
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
TABLE 17-6:
Parameter
No.
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER,
AND BROWN-OUT RESET REQUIREMENTS
Sym
Characteristic
Min
Typ†
Max
Units
Conditions
30*
TMCL
MCLR Pulse Width (low)
2
—
—
s
VDD = 5V, -40°C to +85°C
31*
TWDT
Watchdog Timer Time-out
Period (No Prescaler)
7
18
33
ms
VDD = 5V, -40°C to +85°C
32*
TOST
Oscillation Start-up Timer
Period
—
1024 TOSC
—
—
TOSC = OSC1 period
33*
TPWRT
Power-up Timer Period
28
72
132
ms
VDD = 5V, -40°C to +85°C
34*
TIOZ
I/O Hi-impedance from MCLR
Low or Watchdog Timer Reset
—
—
2.1
s
TBOR
Brown-out Reset pulse width
100
—
—
s
35*
VDD  VBOR (D005)
* These parameters are characterized but not tested.
† Data in "Typ" column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only
and are not tested.
FIGURE 17-8:
BROWN-OUT RESET CHARACTERISTICS
VDD
VBOR
(device not in Brown-out Reset)
(device in Brown-out Reset)
RESET (due to BOR)
72 ms time out
(1)
Note 1: Only if Power-up Timer is enabled. If Timer is disabled, time-out is 0 ms
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PIC16C781/782
FIGURE 17-9:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
RA4/T0CKI
41
40
42
RA6/OSC2/CLKOUT/T1CKI
46
45
47
48
TMR0 or
TMR1
Note: Refer to Figure 17-3 for load conditions.
DS41171B-page 156
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
TABLE 17-7:
Param
No.
TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Sym
Characteristic
Min
Typ†
Max
Units
Conditions
—
—
—
—
ns
ns
Must also meet
parameter 42
Must also meet
parameter 42
40*
TTOH
T0CKI High Pulse Width
No Prescaler
With Prescaler
0.5TCY + 20
10
41*
TTOL
T0CKI Low Pulse Width
No Prescaler
0.5TCY + 20
—
—
ns
10
—
—
ns
TCY + 40
—
—
ns
Greater of:
20 or TCY + 40
N
—
—
ns
N = prescale value
(2, 4, ..., 256)
Must also meet
parameter 47
With Prescaler
42*
TTOP
T0CKI Period
No Prescaler
With Prescaler
45*
TT1H
T1CKI High Time Synchronous, Prescaler = 1
Synchronous,
PIC16C781/782
Prescaler = 2,4,8
Asynchronous
45*
TT1H
PIC16C781/782
T1CKI High Time Synchronous, Prescaler = 1
PIC16LC781/782
Synchronous,
Prescaler = 2,4,8
Asynchronous
46*
TT1L
T1CKI Low Time
PIC16LC781/782
Synchronous, Prescaler = 1
Synchronous,
PIC16C781/782
Prescaler = 2,4,8
Asynchronous
46*
TT1L
T1CKI Low Time
PIC16C781/782
Synchronous, Prescaler = 1
PIC16LC781/782
Synchronous,
Prescaler = 2,4,8
—
—
ns
15
—
—
ns
30
—
—
ns
0.5Tcy + 20
—
—
ns
15
—
—
ns
30
—
—
ns
0.5TCY + 20
—
—
ns
15
—
—
ns
ns
30
—
—
0.5TCY + 20
—
—
ns
15
—
—
ns
Asynchronous
PIC16LC781/782
30
—
—
ns
Synchronous
PIC16C781/782
Greater of:
30 OR TCY + 40
N
—
—
ns
Asynchronous
PIC16C781/782
60
—
—
ns
Synchronous
PIC16LC781/782
Greater of:
30 OR TCY + 40
N
—
—
ns
Asynchronous
PIC16C781/782
47*
TT1P
T1CKI input
period
47*
TT1P
T1CKI input
period
FT 1
Timer1 oscillator input frequency range
(oscillator enabled by setting bit T1OSCEN)
48*
*
†
0.5TCY + 20
60
—
—
ns
DC
—
50
kHz
Must also meet
parameter 47
Must also meet
parameter 47
Must also meet
parameter 47
N = prescale value
(1, 2, 4, 8)
N = prescale value
(1, 2, 4, 8)
— 7TOSC —
Tcke2tmrl Delay from external clock edge to timer increment
2TOSC
These parameters are characterized but not tested.
Data in "Typ" column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
17.4
Operational Amplifier
TABLE 17-8:
DC CHARACTERISTICS: OPERATIONAL AMPLIFIER (OPA)
Standard Operating Conditions (unless otherwise stated):
VDD = 2.7V to 5.5V, TA = 25°C, VCM = VDD/2,
RL = 100 k to VDD/2, and VOUT ~ VDD/2
Operating Temperature -40°C to +85°C for Industrial
DC CHARACTERISTICS
Param
No.
Parameters
Symbol
Min
Typ
Max
Units
Input Offset Voltage
Input Offset Voltage
VOS
TBD
±2
TBD
mV
Prior to Auto Calibration
Input Offset Voltage
Input Offset Voltage
VOS
TBD
±100
TBD
V
Following Auto Calibration
Input Current and Impedance
Input Bias Current
Input Offset Bias Current
IB
IOS
-50
—
—
±1
+50
—
nA
pA
Following Auto Calibration
Common Mode
Common Mode Input Range
Common Mode Rejection
VCM
CMR
VSS
TBD
—
80
VDD-1.4
—
V
dB
Open Loop Gain
DC Open Loop Gain
AOL
—
90
—
dB
DC Open Loop Gain
AOL
—
80
—
dB
DC Open Loop Gain
AOL
—
TBD
—
dB
AOL
—
TBD
—
dB
VOUT
VSS+0.1
—
VDD-0.1
V
ISC
—
25
TBD
mA
DC Open Loop Gain
Output
Output Voltage Swing
Output Short Circuit Current
Conditions
Following Auto Calibration
VDD = 5 V
VCM = VDD/2, Frequency = DC
GBWP = 1 following Auto Calibration
RL = 25 k connected to VDD/2,
50 mV < VOUT < VDD - 50 mV
RL = 5 k connected to VDD/2,
100 mV < VOUT < VDD - 100 mV
GBWP = 0 following Auto Calibration
RL = 50 k connected to VDD/2,
50 mV < VOUT < VDD - 50 mV
RL = 100 k connected to VDD/2,
50 mV < VOUT < VDD - 50 mV
GBWP = 1 Following Auto Calibration
RL = 5 k connected to VDD/2
VDD = 5 V
Power Supply
Power Supply Rejection
PSR
—
80
—
dB
Following Auto Calibration
Auto Calibration Reference
ACR
TBD
1.2
TBD
V
CALREF = 0
DS41171B-page 158
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
TABLE 17-9:
AC CHARACTERISTICS: OPERATIONAL AMPLIFIER (OPA)
Standard Operating Conditions (unless otherwise stated):
VDD = 2.7V to 5.5V, VSS = GND, TA = 25°C, VCM = VDD/2,
RL = 100k to VDD/2, and VOUT = VDD/2
Operating Temperature -40°C to +85°C for Industrial
AC CHARACTERISTICS
Param
No.
Parameters
Symbol
Min
Typ
Max
Units
Conditions
GBWP
—
75
—
kHz
VDD = 5V, GBWP = 0
GBWP
—
2
—
MHz
VDD = 5V, GBWP = 1
TZ
TZ
TON
TON
—
—
—
—
300
TBD
10
TBD
TBD
TBD
TBD
TBD
s
s
s
s
VDD = 5V, GBWP = 1
VDD = 5V GBWP = 0
VDD = 5V, GWBP = 1
VDD = 5V, GBWP = 0
Phase Margin
M
M
—
—
TBD
TBD
—
—
Slew Rate
SR
SR
—
—
TBD
TBD
—
—
Gain Bandwidth Product
Input Offset Auto
Calibration Time
Turn On Time
Note:
degrees VDD = 5V, GBWP = 0
degrees VDD = 5V, GBWP = 1
V/s
V/s
VDD = 5V, GBWP = 0
VDD = 5V, GBWP = 1
Data in ‘Typ’ column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only
and are not tested.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 159
PIC16C781.book Page 160 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
17.5
Comparators
TABLE 17-10: DC CHARACTERISTICS: VOLTAGE COMPARATORS C1 AND C2
Standard Operating Conditions (unless otherwise stated):
VDD = 2.7V to 5.5V, TA = 25°C, VCM = VDD/2
Operating Temperature -40°C to +85°C for Industrial
DC CHARACTERISTICS
Param
No.
Parameters
Symbol
Min
Typ
Max
Units
Input Offset Voltage
VOS
TBD
TBD
±1
± 2.5
TBD
TBD
mV
mV
Input Current and Impedance
Input Bias Current
Input Offset Bias Current
IB
IOS
TBD
—
—
TBD
—
TBD
nA
nA
VCM
CMR
VSS
—
—
70
VDD1.4V
V
dB
Open Loop Gain
DC Open Loop Gain
AOL
—
90
—
dB
Power Supply Rejection
PSR
—
TBD
—
dB
Common Mode
Common Mode Input Range
Common Mode Rejection
Conditions
C1SP = 1, C2SP = 1
C1SP = 0, C2SP = 0
VDD = 5V
VCM = VDD/2, Frequency = DC
VDD = 5V
TABLE 17-11: AC CHARACTERISTICS: COMPARATORS C1 AND C2
Standard Operating Conditions (unless otherwise stated):
VDD = 2.7V to 5.5V, TA = 25°C, VCM = VDD/2
Operating Temperature -40°C to +85°C for Industrial
AC CHARACTERISTICS
Param
No.
Parameters
Response Time
Response Time
Symbol
Min
Typ
Max
Units
Conditions
tr
—
75
—
ns
tr
—
0.5
—
s
tr
—
100
TBD
ns
—
0.5
TBD
s
VDD = 5V,
C1SP = 1, C2SP = 1, Comparator
output signal is for internal use
only,
Input overdrive = 10 mV,
step = 110 mV, VCM = VDD/2.
VDD = 5V,
C1SP = 0, C2SP = 0, Comparator
output signal is for internal use
only,
Input overdrive = 10 mV,
step = 110 mV, VCM = VDD/2.
VDD = 5 , CL = 100 pF,
C1SP = 1, C2SP = 1, Comparator
output is available on I/O pin,
Input overdrive = 10 mV,
step = 110 mV, VCM = VDD/2.
VDD = 5 , CL = 100 pF,
C1SP = 0, C2SP = 0, Comparator
output is available on I/O pin,
Input overdrive = 10 mV,
step = 110 mV, VCM = VDD/2.
—
—
10
TBD
TBD
TBD
s
s
tr
Turn On Time
DS41171B-page 160
TON
Preliminary
C1SP = 0, C2SP = 0, VDD = 5V
C1SP = 1, C2SP = 1, VDD = 5V
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
17.6
Digital-to-Analog Converter (DAC)
TABLE 17-12: DC CHARACTERISTICS: DIGITAL-TO-ANALOG CONVERTER (DAC)
Standard Operating Conditions (unless otherwise stated):
VDD = 2.7V to 5.5V, TA = 25°C
VDD = 5V, DACREF = 5V
Operating Temperature -40°C to +85°C for Industrial
DC CHARACTERISTICS
Param
No.
Parameters
Symbol
Resolution
Min
Typ
RES
Max
Units
8
Conditions
bits
Transfer Function Accuracy
Integral Non-Linearity Error
Differential Non-Linearity Error
Offset Error
Gain Error
INL(1)
DNL(1)
TBD
TBD
TBD
TBD
.25
.10
±2.5
.25
TBD
TBD
TBD
TBD
LSb
LSb
mV
LSb
DACREF Input Characteristics
DACREF Input Impedance
DACREF Input Max Voltage
RREF
VMAX
TBD
TBD
100
—
—
VDD
k
V
Output Characteristics
Output Voltage Range
VOUT
VSS+.05
—
VDD0.05
V
VSS+0.1
—
VDD = 5V, DACREF = 5V
V
VDD-0.1
VDD = 5V
RL = 100 k to VDD/2
VDD = 5V
RL = 25 k to VDD/2
Output Short Circuit Current
ISC*
—
2
TBD
mA
Output Series Resistance
RO*
—
—
TBD
TBD

VDD  3V
VDAC = VDD/2
Power Supply
Power Supply Current
IDAC
—
250
TBD
A
VDD = 5V
VDD = 5V
* Characterized, but not tested.
Note 1: Calculated using end point method.
TABLE 17-13: AC CHARACTERISTICS: DIGITAL-TO-ANALOG CONVERTER (DAC)
Standard Operating Conditions (unless otherwise stated):
VDD = 2.7 V to 5.5 V, TA = 25°C
Operating Temperature-40°C to +85°C for Industrial
AC CHARACTERISTICS
Param
No.
Parameters
Symbol
Min
Typ
Max
Units
Output Characteristics
Slew Rate
SR
—
1
—
Settling Time
TS
—
5
10
s
Turn On Time
TON
—
10
TBD
s
Conditions
V/s VDD = 5 V, CL = 50 pF
VDD = 5 V, CL = 50 pF
Settling time to 1/2 LSb for
10%FS to 90%FS step
VDD = 5 V
Note 1: Data in ‘Typ’ column is at 5V, 25° C unless otherwise stated. These parameters are for design guidance only
and are not tested.
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PIC16C781/782
17.7
Analog Peripherals Characteristics
17.7.1
BANDGAP VOLTAGE
Bandgap voltage is used as the reference voltage in the
PBOR, PLVD, Auto Calibration, and VR modules
FIGURE 17-10: BANDGAP START-UP TIME
VBGAP = 1.32V
(internal use only)
VBGAP
Enable Bandgap
TBGAP
Bandgap Stable
TABLE 17-14: BANDGAP START-UP TIME
Parameter
No.
36*
*
†
Sym
Characteristic
Min
Typ†
Max
Units
Conditions
—
30
—
s
Defined as the time between
the instant that the bandgap
is enabled and the moment
that the bandgap reference
voltage is stable.
TBGAP Bandgap start-up time
These parameters are characterized but not tested.
Data in "Typ" column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only
and are not tested.
17.7.2
VR MODULE
TABLE 17-15: DC CHARACTERISTICS: VR
Standard Operating Conditions (unless otherwise stated):
Operating temperature
-40°C  TA  +85°C for industrial
Operating voltage VDD as described in Section 17.1
DC CHARACTERISTICS
Param
No.
D400
D402*
Symbol
Typ†
Max
Units
VR
Output Voltage
—
3.072
—
V
Output Voltage
Temperature Coefficient
External Load Source
External Load Sink
External Capacitor Load
Load Regulation
—
TBD
TBD
ppm/°C
—
—
—
—
—
—
mA
mA
pF
—
—
1
1
5
-5
200
TBD
TBD
mV/mA
—
—
1
mV/V
IVREFSO
IVREFSI
CL*
D406*
DVOUT/
DIOUT
DVOUT/
DVDD
*
†
Min
TCVOUT
D404*
D405*
D407*
Characteristic
Supply Regulation
Conditions
VDD  3.5V
ISOURCE = 0 mA to 5 mA
ISINK
= 0 mA to 5 mA
These parameters are characterized but not tested.
Data in “Typ” column is at 5V, 25C unless otherwise stated. These parameters are for design guidance
only and are not tested.
DS41171B-page 162
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
17.7.3
PROGRAMMABLE LOW VOLTAGE DETECT MODULE (PLVD)
TABLE 17-16: LOW VOLTAGE DETECT CHARACTERISTICS
VDD
VLVD
(LVDIF set by hardware)
LVDIF
(LVDIF can be cleared in software anytime during
the gray area)
TABLE 17-17: ELECTRICAL CHARACTERISTICS: PLVD
DC CHARACTERISTICS
Param
No.
D420*
Characteristic
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C  TA  +85°C for Industrial
Operating voltage VDD range as described in DC spec Section 17-1.
Symbol
Min
Typ†
Max
Units
Conditions
PLVD Voltage
LV = 0100
VPLVD
2.35
—
2.80
V
—
LV = 0101
2.55
—
3.02
V
—
LV = 0110
2.64
—
3.14
V
—
LV = 0111
2.83
—
3.37
V
—
LV = 1000
3.11
—
3.71
V
—
LV = 1001
3.29
—
3.93
V
—
LV = 1010
3.39
—
4.04
V
—
LV = 1011
3.58
—
4.26
V
—
LV = 1100
3.77
—
4.49
V
—
LV = 1101
3.95
—
4.71
V
—
LV = 1110
4.23
—
5.05
V
—
† Data in “Typ” column is at 5V, 25C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: Production tested at TAMB = 25°C. Specifications over temperature limits ensured by characterization.
 2001-2013 Microchip Technology Inc.
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DS41171B-page 163
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PIC16C781/782
17.7.4
PROGRAMMABLE BROWN-OUT RESET MODULE DC CHARACTERISTICS: PBOR
DC CHARACTERISTICS
Param
No.
Standard Operating Conditions (unless otherwise stated):
Operating temperature-40°C  TA  +85°C for Industrial
Operating voltage VDD range as described in DC spec Section 17-1.
Characteristic
D005*
BOR Voltage
BORV<1:0> = 11
BORV<1:0> = 10
BORV<1:0> = 01
BORV<1:0> = 00
Symbol
Min
Typ
Max
Units
Conditions
VBOR
2.35
2.55
3.95
4.23
—
—
—
—
2.80
3.02
4.71
5.05
V
—
—
—
—
TABLE 17-18: ADC CONVERTER CHARACTERISTICS PIC16C781/782
Param
No.
Sym
Characteristic
Min
Typ†
Max
Units
Conditions
A01
NR
Resolution
—
—
8
bits
ADCREF = AVDD = 5.12V,
VSS  VAIN  ADCREF
A02
EABS
Absolute Error
—
—
< 1
LSb
ADCREF = AVDD = 5.12V,
VSS  VAIN  ADCREF
—
—
< 2
LSb
ADCREF = AVDD = 3.0V(3)
A03
INL
Integral Now Linearity Error
—
—
< 1
LSb
ADCREF = AVDD = 5.12V,
VSS  VAIN  ADCREF
—
—
< 2
LSb
ADCREF = AVDD = 3.0V(3)
A04
DNL
Differential Now Linearity
Error
—
—
< 1
LSb
ADCREF = AVDD = 5.12V,
VSS  VAIN  ADCREF
—
—
< 2
LSb
ADCREF = AVDD = 3.0V(3)
—
—
< 1
LSb
ADCREF = AVDD = 5.12V,
VSS VAIN  ADCREF
—
—
< 2
LSb
ADCREF = AVDD = 3.0V(3)
—
—
< 1
LSb
ADCREF = AVDD = 5.12V,
VSS  VAIN  ADCREF
—
—
< 2
LSb
ADCREF = AVDD = 3.0V(3)
A05
GN
Gain Error
A06
EOFF
Offset Error
—
—
VSS  VAIN  ADCREF
3.0V
—
VDD + 0.3
V
—
VSS - 0.3
—
ADCREF
V
—
—
—
10.0
k
—
ADC Conversion Current
(VDD)
—
180
—
A
Average current consumption
when ADC is on.(1)
ADCREF Input Current(2)
10
—
1000
A
—
—
40
A
During VAIN acquisition.
Based on differential of VHOLD
to VAIN.
To charge CHOLD, see
Section 9.3.
During ADC Conversion cycle.
A10
—
Monotonicity
A20
ADCREF
Reference Voltage
A25
VAIN
Analog Input Voltage
A30
ZAIN
Recommended Impedance
of Analog Voltage Source
A40
IADC
A50
IREF
*
†
Note 1:
2:
3:
4:
—
guaranteed
(4)
These parameters are characterized but not tested.
Data in “Typ” column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not
tested.
When ADC is off, it will not consume any current other than minor leakage current. The power-down current specification
(D020A) includes any such leakage from the ADC module.
ADCREF current is from RA3/AN3/VREF1 pin or AVDD pin, whichever is selected as reference input.
These specifications apply if ADCREF = 3.0 V and if AVDD  3.0 V. VAIN must be between VSS and ADCREF.
The A/D conversion result never decreases with an increase in the Input Voltage and has no missing codes.
DS41171B-page 164
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
FIGURE 17-11:
ADC CONVERSION TIMING
BSF ADCON0, GO
1 TCY
(TOSC/2)(1)
131
Q4
130
ADC CLK
132
7
ADC DATA
6
5
4
3
2
1
0
NEW_DATA
OLD_DATA
ADRES
ADIF
CONVERSION
COMPLETE
GO/DONE
SAMPLING STOPPED
SAMPLE
Note
1:
If the ADC clock source is selected as RC, a time of TCY is added before the ADC clock starts. This allows the SLEEP instruction
to be executed.
TABLE 17-19: ADC CONVERSION REQUIREMENTS
Param
No.
Sym
Characteristic
130
TAD
ADC clock period
ADC Internal RC
Oscillator Period
131
TCNV
Conversion time (not including S/H time)(1)
132
TACQ
Acquisition time(2)
134
135
PIC16C781/782
PIC16LC781/782
TGO
Q4 to ADC clock start
TSWC
Switching from convert  sample time
Min
Typ†
Max
Units
Conditions
2.0
TBD
4.0
TBD
6.0
TBD
µs
µs
—
9.5
—
TAD
20
—
s
5*
—
—
s
The minimum time is the amplifier settling time. This may be
used if the "new" input voltage
has not changed by more than
1 LSb (i.e., 19.5 mV @ 5.12V)
from the last sampled voltage
(as stated on CHOLD).
—
TOSC/2§
—
—
If the ADC clock source is
selected as RC, a time of TCY is
added before the ADC clock
starts. This allows the SLEEP
instruction to be executed.
1.5§
—
—
TAD
ADC RC mode
*
†
These parameters are characterized but not tested.
Data in “Typ” column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not
tested.
§ These specifications ensured by design.
Note 1: ADRES register may be read on the following TCY cycle.
2: See Section 13.1 for min. conditions.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 165
PIC16C781.book Page 166 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
NOTES:
DS41171B-page 166
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 167 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
18.0
DC AND AC
CHARACTERISTICS GRAPHS
AND TABLES
The graphs and tables provided in this section are for
design guidance and are not tested nor guaranteed. In
some graphs or tables the data presented is outside
specified operating range (e.g., outside specified VDD
range.). This is for information only and devices are
ensured to operate properly only within the specified
range. The data presented in this section is a statistical
summary of data collected on units from different lots
over a period of time.
Standard deviation is denoted by sigma ( ).
Typ or Typical represents the mean of the distribution
at 25°C.
Max or Maximum represents the mean +3 over the
temperature range of -40°C to 85°C.
Min or Minimum represents the mean -3 over the temperature range of -40°C to 85°C.
Graphs and Tables are not available at this time.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 167
PIC16C781.book Page 168 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
NOTES:
DS41171B-page 168
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 169 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
19.0
PACKAGING INFORMATION
19.1
Package Marking Information
20-Lead SSOP
Example
XXXXXXXXXXX
XXXXXXXXXXX
YYWWNNN
PIC16C781
-I/SS
0107017
20-Lead CERDIP Windowed
Example
PIC16C781
/JW
XXXXXXXX
XXXXXXXX
YYWWNNN
20-Lead SOIC
Example
XXXXXXXXXXXXXX
XXXXXXXXXXXXXX
XXXXXXXXXXXXXX
YYWWNNN
PIC16C781/SO
0110017
Example
20-Lead PDIP
XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXX
YYWWNNN
Legend: XX...X
Y
YY
WW
NNN
e3
*
Note:
0105017
PIC16C781-I/P
0110017
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.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 169
PIC16C781.book Page 170 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
20-Lead Plastic Shrink Small Outline (SS) – 209 mil, 5.30 mm (SSOP)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located
at http://www.microchip.com/packaging
E
E1
p
D
B
2
1
n

c
A2
A

L
A1

Units
Dimension Limits
n
p
Number of Pins
Pitch
Overall Height
Molded Package Thickness
Standoff §
Overall Width
Molded Package Width
Overall Length
Foot Length
Lead Thickness
Foot Angle
Lead Width
Mold Draft Angle Top
Mold Draft Angle Bottom
A
A2
A1
E
E1
D
L
c

B


MIN
.068
.064
.002
.299
.201
.278
.022
.004
0
.010
0
0
INCHES*
NOM
20
.026
.073
.068
.006
.309
.207
.284
.030
.007
4
.013
5
5
MAX
.078
.072
.010
.322
.212
.289
.037
.010
8
.015
10
10
MILLIMETERS
NOM
20
0.65
1.73
1.85
1.63
1.73
0.05
0.15
7.59
7.85
5.11
5.25
7.06
7.20
0.56
0.75
0.10
0.18
0.00
101.60
0.25
0.32
0
5
0
5
MIN
MAX
1.98
1.83
0.25
8.18
5.38
7.34
0.94
0.25
203.20
0.38
10
10
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MO-150
Drawing No. C04-072
DS41171B-page 170
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 171 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
20-Lead CERDIP Windowed
Diagram not available at this time.
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 171
PIC16C781.book Page 172 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
20-Lead Plastic Small Outline (SO) – Wide, 300 mil (SOIC)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located
at http://www.microchip.com/packaging
E
E1
p
D
2
B
n
1
h

45
c
A2
A


A1
L
Units
Dimension Limits
n
p
Number of Pins
Pitch
Overall Height
Molded Package Thickness
Standoff §
Overall Width
Molded Package Width
Overall Length
Chamfer Distance
Foot Length
Foot Angle
Lead Thickness
Lead Width
Mold Draft Angle Top
Mold Draft Angle Bottom
* Controlling Parameter
§ Significant Characteristic
A
A2
A1
E
E1
D
h
L

c
B


MIN
.093
.088
.004
.394
.291
.496
.010
.016
0
.009
.014
0
0
INCHES*
NOM
20
.050
.099
.091
.008
.407
.295
.504
.020
.033
4
.011
.017
12
12
MAX
.104
.094
.012
.420
.299
.512
.029
.050
8
.013
.020
15
15
MILLIMETERS
NOM
20
1.27
2.36
2.50
2.24
2.31
0.10
0.20
10.01
10.34
7.39
7.49
12.60
12.80
0.25
0.50
0.41
0.84
0
4
0.23
0.28
0.36
0.42
0
12
0
12
MIN
MAX
2.64
2.39
0.30
10.67
7.59
13.00
0.74
1.27
8
0.33
0.51
15
15
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-013
Drawing No. C04-094
DS41171B-page 172
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 173 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
20-Lead Plastic Dual In-line (P) – 300 mil (PDIP)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located
at http://www.microchip.com/packaging
E1
D
2
n

1
E
A2
A
L
c
A1

B1
eB
p
B
Units
Dimension Limits
n
p
MIN
INCHES*
NOM
20
.100
.155
.130
MAX
MILLIMETERS
NOM
20
2.54
3.56
3.94
2.92
3.30
0.38
7.49
7.87
6.10
6.35
26.04
26.24
3.05
3.30
0.20
0.29
1.40
1.52
0.36
0.46
7.87
9.40
5
10
5
10
MIN
Number of Pins
Pitch
Top to Seating Plane
A
.140
.170
Molded Package Thickness
A2
.115
.145
Base to Seating Plane
A1
.015
Shoulder to Shoulder Width
E
.295
.310
.325
Molded Package Width
E1
.240
.250
.260
Overall Length
D
1.025
1.033
1.040
Tip to Seating Plane
L
.120
.130
.140
c
Lead Thickness
.008
.012
.015
Upper Lead Width
B1
.055
.060
.065
Lower Lead Width
B
.014
.018
.022
Overall Row Spacing
§
eB
.310
.370
.430

Mold Draft Angle Top
5
10
15

Mold Draft Angle Bottom
5
10
15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-001
Drawing No. C04-019
 2001-2013 Microchip Technology Inc.
Preliminary
MAX
4.32
3.68
8.26
6.60
26.42
3.56
0.38
1.65
0.56
10.92
15
15
DS41171B-page 173
PIC16C781.book Page 174 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
NOTES:
DS41171B-page 174
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 175 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
INDEX
A
BOR
ADC
DC Characteristics.................................................... 164
BOR. See Brown-out Reset
Brown-out Reset (BOR).................................... 117, 125, 126
Buck Configuration LC Power Supply............................... 112
Buck LC Switching Power Supply..................................... 110
Accuracy/Error ............................................................ 75
Connection Considerations......................................... 76
Conversion Time ......................................................... 75
Converter Characteristics ......................................... 164
Effects of a RESET ..................................................... 76
Faster Conversion - Lower Resolution Trade-off ........ 75
Flow Chart of ADC Operation ..................................... 77
References.................................................................. 76
Transfer Function ........................................................ 76
ADC Acquisition Requirements........................................... 73
ADC Conversion Clock ....................................................... 72
ADC Minimum Charging Time ............................................ 73
ADC Operation During SLEEP ........................................... 75
Analog Signal Multiplexing Diagram ..................................... 7
Analog-to-digital Converter (ADC) Module ......................... 69
Analog-to-Digital Converter Module
Control Registers ........................................................ 70
Assembler
MPASM Assembler ................................................... 141
B
Banking, Data Memory ....................................................... 17
Block Diagrams
ADC Module................................................................ 69
Auto Calibration Module.............................................. 85
Comparator C1 Simplified........................................... 90
Comparator C2 Simplified........................................... 90
DAC Converter............................................................ 80
Low Voltage Detect ..................................................... 64
On-Chip Reset Circuit ............................................... 121
OPA Module................................................................ 83
PIC16C781 ................................................................... 5
PIC16C782 ................................................................... 6
PSMC Module in Dual Alternating Output
PWM Mode ............................................................... 100
PSMC Module in Single Output PSM Mode ............. 102
PSMC Module in Single Output PWM Mode .............. 99
RA0/AN0/OPA+ Pin .................................................... 27
RA1/AN1/OPA- Pin ..................................................... 28
RA2/AN2/VREF2 Pin .................................................. 29
RA3/AN3/VREF1 Pin .................................................. 30
RA4/T0CKI Pin............................................................ 31
RA5/MCLR/VPP.......................................................... 32
RA6/OSC2/CLKOUT/T1CKI Pin ................................. 33
RA7/OSC1/CLKIN Pin ................................................ 34
RB0/INT/AN4/VR Pin .................................................. 37
RB1/AN5/VDAC Pin.................................................... 38
RB2/AN6 Pin............................................................... 39
RB3/AN7/OPA Pin ...................................................... 40
RB4 Pin....................................................................... 41
RB5 Pin....................................................................... 42
RB6/C1/PSMC1A Pin ................................................. 43
RB7/C2/PSMC1B/T1G Pin ......................................... 44
RC Oscillator Mode................................................... 120
Timer0 ......................................................................... 51
Timer0/WDT Prescaler................................................ 53
TIMER1....................................................................... 58
Watchdog Timer (WDT) ............................................ 130
Boost LC Switching Power Supply.................................... 107
 2001-2013 Microchip Technology Inc.
C
C1 Input to PSMC w/DAC as Reference ............................ 95
C2 Configuration Program.................................................. 95
CALCON Register .............................................................. 84
Calculating the Minimum Required
Acquisition Time ................................................................. 73
Clock Noise......................................................................... 76
Code Examples
Doing an ADC Conversion ......................................... 74
Code Protection................................................................ 117
Comparator C1 Control Register ........................................ 89
Comparator C2 Configuration With Output
Synchronized to T1CKI....................................................... 95
Comparator C2 Control Registers ...................................... 92
Comparator C2 Synchronized to T1CKI ............................. 95
Comparator Configuration .................................................. 95
Comparator Module............................................................ 89
Associated Registers.................................................. 98
Control Registers........................................................ 89
Effects of a RESET..................................................... 98
Output State Versus Input Conditions......................... 89
Configuration as OPAMP or Comparator ........................... 86
Configuration Bits ............................................................. 117
Configuration of Comparator C1 with DAC......................... 96
Configuring the ADC Module .............................................. 72
Configuring the Reference Voltages................................... 72
Control Register CM2CON0 ............................................... 92
Control Register T1CON..................................................... 56
D
DAC Configuration.............................................................. 81
DAC Module
Accuracy/Error............................................................ 81
Associated Registers/Bits........................................... 81
DAC Transfer Function ............................................... 81
Differential Non-Linearity Error ................................... 81
Effects of a RESET..................................................... 81
Gain Error ................................................................... 81
Integral Non-Linearity Error ........................................ 81
Monotonicity ............................................................... 81
Offset Error ................................................................. 81
Data Memory
Bank Select (RP Bits) ................................................. 17
Data Memory Organization................................................. 11
Register File Map ....................................................... 12
DC Characteristics
PIC16C781/782, PIC16LC781/782
(Industrial)......................................................... 149
Development Support....................................................... 141
Device Overview................................................................... 5
Digital-to-Analog Converter (DAC) Module......................... 79
Control Registers........................................................ 79
Direct Addressing ............................................................... 24
Preliminary
DS41171B-page 175
PIC16C781.book Page 176 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
E
EC Mode ........................................................................... 119
Effect of RESET on Core Registers .................................... 24
Summary..................................................................... 24
Effects of RESET ................................................................ 52
Electrical Characteristics................................................... 147
Errata .................................................................................... 3
Examples
DAC Configuration ...................................................... 81
OPAMP Calibration Mode Configuration..................... 86
Peripheral Configuration ........................................... 113
PSMC Configuration ................................................. 109
PSMC Configuration Example for a Buck
Mode Switching Power Supply ................................. 111
Window Comparator ................................................... 97
External Power-on Reset Circuit ....................................... 122
F
Firmware Instructions........................................................ 133
FSR Register....................................................................... 15
G
General Purpose Register File............................................ 13
I
I/O Port Analog/Digital Mode............................................... 25
I/O Ports .............................................................................. 25
ICEPIC In-Circuit Emulator ............................................... 142
ID Locations ...................................................................... 117
In-Circuit Serial Programming (ICSP) ............................... 117
Indirect Addressing ............................................................. 24
Initialization Condition for All Registers............................. 126
Initializing Timer0 ................................................................ 51
Instruction Format ............................................................. 133
Instruction Set ................................................................... 133
ADDLW ..................................................................... 135
ADDWF ..................................................................... 135
ANDLW ..................................................................... 135
ANDWF ..................................................................... 135
BCF ........................................................................... 135
BSF ........................................................................... 135
BTFSC ...................................................................... 136
BTFSS ...................................................................... 135
CALL ......................................................................... 136
CLRF......................................................................... 136
CLRW........................................................................ 136
CLRWDT................................................................... 136
COMF ....................................................................... 136
DECF ........................................................................ 136
DECFSZ.................................................................... 137
GOTO........................................................................ 137
INCF.......................................................................... 137
INCFSZ ..................................................................... 137
IORLW....................................................................... 137
IORWF ...................................................................... 137
MOVF........................................................................ 138
MOVLW..................................................................... 138
MOVWF .................................................................... 138
NOP .......................................................................... 138
RETFIE ..................................................................... 138
RETLW...................................................................... 138
RETURN ................................................................... 138
RLF ........................................................................... 138
RRF........................................................................... 139
SLEEP ...................................................................... 139
DS41171B-page 176
SUBLW ..................................................................... 139
SUBWF..................................................................... 139
SWAPF ..................................................................... 139
XORLW..................................................................... 139
XORWF .................................................................... 140
INT Interrupt (RB0/INT/AN4/VR). See Interrupt Sources
INTCON Register
GIE Bit ........................................................................ 19
INTE Bit ...................................................................... 19
INTF Bit ...................................................................... 19
PEIE Bit ...................................................................... 19
RBIE Bit ...................................................................... 19
RBIF Bit ...................................................................... 19
T0IE Bit....................................................................... 19
T0IF Bit ....................................................................... 19
Interrupt Sources ...................................................... 117, 128
RB0/INT Pin, External............................................... 128
TMR0 Overflow................................................... 52, 129
Interrupts, Context Saving During..................................... 129
Interrupts, Enable Bits
Global Interrupt Enable (GIE Bit).............................. 128
Interrupt-on-Change (RB7:RB0) Enable
(RBIE Bit).................................................................. 129
Interrupts, Flag Bits
Interrupt-on-Change (RB7:RB4) Flag
(RBIF Bit).................................................................. 129
TMR0 Overflow Flag (T0IF Bit)................................. 129
K
KEELOQ Evaluation and Programming Tools .................... 144
L
Low Power Window Comparator with Interrupt .................. 96
Low Voltage Detect
Associated Register Summary ................................... 67
Low Voltage Detect Registers ............................................ 67
Low Voltage Detect Waveforms ......................................... 65
LP, XT and HS Modes ...................................................... 119
M
Master Clear (MCLR)
MCLR Reset, Normal Operation....................... 125, 126
MCLR Reset, SLEEP................................ 121, 125, 126
Memory Organization ......................................................... 11
MPLAB C17 and MPLAB C18 C Compilers ..................... 141
MPLAB ICD In-Circuit Debugger ...................................... 143
MPLAB ICE High Performance Universal
In-Circuit Emulator with MPLAB IDE ................................ 142
MPLAB Integrated Development
Environment Software ...................................................... 141
MPLINK Object Linker/MPLIB Object Librarian ................ 142
O
OPA Auto Calibration.......................................................... 83
OPA Module
Associated Registers .................................................. 87
Common Mode Voltage Range................................... 86
Effects of a RESET..................................................... 86
Gain Bandwidth Product ............................................. 86
Input Offset Voltage .................................................... 86
Leakage Current......................................................... 86
Open Loop Gain ......................................................... 86
OPA Offset Voltage ............................................................ 84
OPCODE Field Descriptions............................................. 133
Operational Amplifier (OPA) Module .................................. 83
Preliminary
 2001-2013 Microchip Technology Inc.
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PIC16C781/782
OPTION_REG Register
INTEDG Bit ................................................................. 18
PS Bits .................................................................. 18, 52
PSA Bit.................................................................. 18, 52
RBPU Bit..................................................................... 18
T0CS Bit................................................................ 18, 51
T0SE Bit................................................................ 18, 51
Oscillator Configuration..................................................... 119
CLKOUT ................................................................... 120
Dual Speed Operation for INTRC Modes.................. 120
EC ..................................................................... 119, 123
ER ............................................................................. 119
HS ..................................................................... 119, 123
INTRC ............................................................... 119, 123
LP...................................................................... 119, 123
XT ..................................................................... 119, 123
Oscillator, WDT ................................................................. 129
Oscillators
RC, Block Diagram ................................................... 120
OTP Program Memory Read .............................................. 49
P
Package Marking Information ........................................... 169
Paging, Program Memory ................................................... 23
PCON Register ................................................................. 123
BOR Bit ....................................................................... 22
OSCF Bit..................................................................... 22
POR Bit ....................................................................... 22
WDTON Bit ................................................................. 22
PICDEM 1 Low Cost PIC MCU
Demonstration Board ........................................................ 143
PICDEM 17 Demonstration Board .................................... 144
PICDEM 2 Low Cost PIC16CXX
Demonstration Board ........................................................ 143
PICDEM 3 Low Cost PIC16CXXX
Demonstration Board ........................................................ 144
PICSTART Plus Entry Level
Development Programmer ................................................ 143
Pin Functions
AVDD ............................................................................. 9
AVSS .............................................................................. 9
RA0/AN0/OPA+............................................................. 8
RA1/AN1/OPA- ............................................................. 8
RA2/AN2/VREF2 ............................................................ 8
RA3/AN3/VREF1 ............................................................ 8
RA4/T0CKI.................................................................... 8
RA5/MCLR/VPP............................................................. 8
RA6/OSC2/CLKOUT/T1CKI ......................................... 8
RA7/OSC1/CLKIN......................................................... 8
RB0/INT/AN4/VR ........................................................... 8
RB1/AN5/VDAC ............................................................. 8
RB2/AN6 ....................................................................... 8
RB3/AN7/OPA............................................................... 8
RB4 ............................................................................... 8
RB5 ............................................................................... 8
RB6/C1/PSMC1A.......................................................... 8
RB7/C2/PSMC1B/T1G.................................................. 9
VDD ............................................................................... 9
VSS ................................................................................ 9
Pinout Description
PIC16C781/782 ............................................................ 8
 2001-2013 Microchip Technology Inc.
PIR1 Register
ADIF Bit ...................................................................... 21
C1IF Bit....................................................................... 21
C2IF Bit....................................................................... 21
LVDIF Bit .................................................................... 21
TMR1IF Bit ................................................................. 21
PLVD
DC Characteristics.................................................... 163
PLVD Example ................................................................... 67
PMCON1 ............................................................................ 47
PMDATH and PMDATL Registers...................................... 47
PMR
Associated Register Summary ................................... 50
Pointer, FSR ....................................................................... 23
POR. See Power-on Reset
PORTA
Associated Register Summary ................................... 34
Initialization................................................................. 26
PORTA and the TRISA Register ........................................ 26
PORTB
Associated Register Summary ................................... 45
Initialization................................................................. 35
Pull-up Enable (RBPU Bit).......................................... 18
RB0/INT Edge Select (INTEDG Bit) ........................... 18
RB0/INT Pin, External .............................................. 128
RB7:RB0 Interrupt-on-Change Enable
(RBIE Bit).................................................................. 129
RB7:RB4 Interrupt-on-Change ................................. 129
RB7:RB4 Interrupt-on-Change Flag
(RBIF Bit).................................................................. 129
PORTB and the TRISB Register ........................................ 35
PORTB Interrupt-on-Change .............................................. 35
PORTB Weak Pull-up ......................................................... 35
Postscaler, WDT................................................................. 52
Assignment (PSA Bit) ........................................... 18, 52
Rate Select (PS Bits)............................................ 18, 52
Switching Between Timer0 and WDT ......................... 52
Power-down Mode. See SLEEP
Power-on Reset (POR)..................... 117, 121, 122, 125, 126
Oscillator Start-up Timer (OST) ................................ 117
Power Control (PCON) Register............................... 123
Power-down (PD Bit) .................................................. 17
Power-on Reset Circuit, External ............................. 122
Power-up Timer (PWRT) .................................. 117, 122
Time-out (TO Bit) ........................................................ 17
Time-out Sequence .................................................. 122
Time-out Sequence on Power-up ..................... 125, 127
Prescaler, Timer0 ............................................................... 52
Assignment (PSA Bit) ........................................... 18, 52
Rate Select (PS Bits)............................................ 18, 52
Switching Between Timer0 and WDT ......................... 52
Prescaler, Timer1
Select (T1CKPS1:T1CKPS0 Bits) .............................. 57
PRO MATE II Universal Device Programmer ................... 143
Program .............................................................................. 47
Program Counter
PCL Register .............................................................. 23
PCLATH Register ............................................... 23, 129
Reset Conditions ...................................................... 125
Program Memory
Paging ........................................................................ 23
Program Memory Map and Stack
PIC16C781 ................................................................. 11
PIC16C782 ................................................................. 11
Program Memory Organization........................................... 11
Preliminary
DS41171B-page 177
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PIC16C781/782
Program Memory Read (PMR) ........................................... 47
Program Memory Read Cycle Execution ............................ 50
Programmable Brown-out Reset (PBOR) ................. 121, 122
Programmable Low Voltage Detect
Module (PLVD).................................................................... 63
Control Register .......................................................... 63
Effects of a RESET ..................................................... 67
Operation .................................................................... 64
Operation During SLEEP ............................................ 67
Programmable Switch Mode Controller (PSMC)................. 99
Programming C1 for PSMC Feedback................................ 96
Programming, Device Instructions .................................... 133
PSMC
Associated Registers ................................................ 115
Configuration............................................................. 107
Control Registers ...................................................... 104
Effects of SLEEP and RESET................................... 115
PSMC1A Operation in PSM Mode Using
C1 Comparator Only ......................................................... 102
PSMC1A Output Sequence in PSM Mode
Using C1 and C2 Comparators ......................................... 103
PSMC1A Output Sequence in PWM Mode
Using C1 and C2 Comparators ......................................... 101
PSMC1A Output Sequence in PWM Mode
Using C1 Comparator Only ............................................... 100
PSMCCON0 Register ....................................................... 104
PSMCCON1 Register ....................................................... 104
Pulse Skip Modulation (PSM) ........................................... 102
Pulse Width Modulation (PWM) .......................................... 99
R
Read with Code Protect Set................................................ 50
Reading the EPROM Program Memory.............................. 49
Registers
ADC Control Register (ADCON1) ............................... 71
ADC Control Register 0 (ADCON0) ............................ 70
ADC Result Register (ADRES) ................................... 71
Analog Select .............................................................. 25
Calibration Control Register (CALCON) ..................... 85
Comparator C1 Control Register0
(CM1CON0) ................................................................ 91
Comparator C2 Control Register0
(CM2CON0) ................................................................ 93
Comparator C2 Control Register1
(CM2CON1) ................................................................ 94
Digital-to-Analog Converter Control Register0
(DACON)..................................................................... 79
Digital-to-Analog Converter Register (DAC) ............... 79
INTCON ...................................................................... 19
Interrupt-on-Change PORTB ...................................... 36
OPAMP Control Register (OPACON).......................... 84
OPTION_REG ............................................................ 18
PCON.......................................................................... 22
PIE1 ............................................................................ 20
Program memory Address High (PMADRH)............... 48
Program Memory Address Low (PMADRL) ................ 48
Program memory Data High (PMDATH) ..................... 47
Program Memory Data Low (PMDATL) ...................... 48
Program Memory Read Control Register 1
(PMCON1) .................................................................. 47
Programmable Low Voltage Detect Register
(LVDCON) ................................................................... 66
PSMC Control Register0 (PSMCCON0) ................... 105
PSMC Control Register1 (PSMCCON1) ................... 106
STATUS ...................................................................... 17
DS41171B-page 178
Timer1 Control Register (T1CON) .............................. 57
Voltage Reference Control Register (REFCON)......... 61
Weak Pull-up PORTB ................................................. 36
Registers Associated with VR............................................. 61
Registers/Bits Associated with ADC ................................... 77
Reset ................................................................................ 121
Brown-out Reset (BOR). See Brown-out Reset (BOR)
Power-on Reset (POR). See Power-on Reset (POR)
Reset Conditions for PCON Register ....................... 125
Reset Conditions for Program Counter..................... 125
Reset Conditions for STATUS Register .................... 125
WDT Reset. See Watchdog Timer (WDT)
S
Setting up the PLVD Module .............................................. 65
Single or Dual Output ....................................................... 103
SLEEP .............................................................. 117, 121, 131
Slope Compensation ........................................................ 103
Slope Compensation (SC) Switch Operation.................... 103
Software Simulator (MPLAB SIM) .................................... 142
Special Features of the CPU ............................................ 117
Special Function Registers ................................................. 13
ADCON0 Register ...................................................... 13
ADCON1 Register ...................................................... 14
ADRES Register......................................................... 13
ANSEL Register.......................................................... 14
CALCON Register ...................................................... 15
CM1CON0 Register.................................................... 15
CM2CON0 Register.................................................... 15
CM2CON1 Register.................................................... 15
DAC Register.............................................................. 15
DACON0 Register ...................................................... 15
FSR Register .................................................. 13, 14, 16
INDF Register ........................................... 13, 14, 15, 16
INTCON Register...................................... 13, 14, 15, 16
IOCB Register............................................................. 14
LVDCON Register....................................................... 14
OPACON Register ...................................................... 15
OPTION_REG Register........................................ 14, 16
PCL Register ............................................ 13, 14, 15, 16
PCLATH Register ..................................... 13, 14, 15, 16
PCON Register........................................................... 14
PIE1 Register ............................................................. 14
PIR1 Register ............................................................. 13
PMADRH Register...................................................... 15
PMADRL Register ...................................................... 15
PMCON1 Register...................................................... 16
PMDATH Register ...................................................... 15
PMDATL Register ....................................................... 15
PORTA Register ......................................................... 13
PORTB Register ................................................... 13, 15
PSMCCON0 Register ................................................. 15
PSMCCON1 Register ................................................. 15
REFCON Register ...................................................... 14
STATUS Register...................................... 13, 14, 15, 16
Summary .................................................................... 13
T1CON Register ......................................................... 13
TMR0 Register...................................................... 13, 15
TMR1H Register......................................................... 13
TMR1L Register.......................................................... 13
TRISA Register........................................................... 14
TRISB Register..................................................... 14, 16
WPUB Register........................................................... 14
Stack................................................................................... 23
STATUS Register ............................................................. 129
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 179 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
C Bit ............................................................................ 17
DC Bit.......................................................................... 17
IRP Bit......................................................................... 17
PD Bit.......................................................................... 17
RP Bits ........................................................................ 17
TO Bit.......................................................................... 17
Zero Bit ....................................................................... 17
T
T1CON Register
T1CKPS1:T1CKPS0 Bits ............................................ 57
T1OSCEN Bit.............................................................. 57
TMR1CS Bit ................................................................ 57
TMR1ON Bit................................................................ 57
TAD vs. Device Operating Frequencies............................... 72
Timer0 ................................................................................. 51
Associated Registers .................................................. 53
Clock Source Edge Select (T0SE Bit)......................... 51
Clock Source Select (T0CS Bit)............................ 18, 51
Overflow Flag (T0IF Bit)............................................ 129
Overflow Interrupt ............................................... 52, 129
Prescaler. See Prescaler, Timer0
Timer0 Module .................................................................... 51
Timer0 Operation ................................................................ 51
Timer1
Associated Registers Summary.................................. 59
Clock Source Select (TMR1CS Bit) ............................ 57
Effects of a RESET ..................................................... 59
Module On/Off (TMR1ON Bit)..................................... 57
Oscillator Enable (T1OSCEN Bit) ............................... 57
Timer1 Incrementing Edge.................................................. 58
Timer1 Initialization ............................................................. 55
Timer1 Interrupt .................................................................. 59
Timer1 Module Timer/Counter ............................................ 55
Timer1 Module with Gate Control ....................................... 55
Timer1 Operation ................................................................ 55
Timer1 Oscillator for the PIC16C781/782 ........................... 59
Timing Diagrams
ADC Conversion ....................................................... 165
Brown-out Reset ....................................................... 154
CLKOUT and I/O....................................................... 152
External Clock........................................................... 153
External Clock Timing ............................................... 152
RESET, Watchdog Timer, Oscillator Start-up Timer
and Power-up Timer.................................................. 154
Time-out Sequence on Power-up ..................... 125, 127
Timer0 ....................................................................... 156
Timer0 and Timer1 External Clock............................ 156
Timer1 ....................................................................... 156
Wake-up from SLEEP via Interrupt ........................... 132
TRISA, ANSEL, and Control Precedence ........................... 26
TRISB, ANSEL, and Control Precedence ........................... 36
Typical Low Voltage Detect Application .............................. 63
 2001-2013 Microchip Technology Inc.
V
Voltage Reference Module
Effects of a RESET..................................................... 61
Voltage Reference Module (VR)......................................... 61
W
W Register ........................................................................ 129
Wake-up from SLEEP............................................... 117, 131
Interrupts .......................................................... 125, 126
MCLR Reset ............................................................. 126
Timing Diagram ........................................................ 132
WDT Reset ............................................................... 126
Watchdog Timer
Associated Register Summary ................................. 130
Watchdog Timer (WDT)............................................ 117, 129
Enable (WDTE Bit) ................................................... 129
Postscaler. See Postscaler, WDT
Programming Considerations ................................... 129
RC Oscillator ............................................................ 129
Time-out Period ........................................................ 129
WDT Reset, Normal Operation................. 121, 125, 126
WDT Reset, SLEEP ......................................... 125, 126
Window Comparator with Interrupt ..................................... 96
WWW, On-Line Support ....................................................... 3
Preliminary
DS41171B-page 179
PIC16C781.book Page 180 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
NOTES:
DS41171B-page 180
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 181 Tuesday, January 29, 2013 3:29 PM
THE MICROCHIP WEB SITE
CUSTOMER SUPPORT
Microchip provides online support via our WWW site at
www.microchip.com. This web site is used as a means
to make files and information easily available to
customers. Accessible by using your favorite Internet
browser, the web site contains the following
information:
Users of Microchip products can receive assistance
through several channels:
• Product Support – Data sheets and errata,
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• General Technical Support – Frequently Asked
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• Business of Microchip – Product selector and
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•
•
•
•
Distributor or Representative
Local Sales Office
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Technical Support
Customers
should
contact
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support. Local sales offices are also available to help
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included in the back of this document.
Technical support is available through the web site
at: http://microchip.com/support
CUSTOMER CHANGE NOTIFICATION
SERVICE
Microchip’s customer notification service helps keep
customers current on Microchip products. Subscribers
will receive e-mail notification whenever there are
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To register, access the Microchip web site at
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“Customer Change Notification” and follow the
registration instructions.
 2001-2013 Microchip Technology Inc.
DS41171B-page 181
PIC16C781.book Page 182 Tuesday, January 29, 2013 3:29 PM
READER RESPONSE
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip
product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our
documentation can better serve you, please FAX your comments to the Technical Publications Manager at
(480) 792-4150.
Please list the following information, and use this outline to provide us with your comments about this document.
TO:
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Application (optional):
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Device:
Literature Number: DS41171B
Questions:
1. What are the best features of this document?
2. How does this document meet your hardware and software development needs?
3. Do you find the organization of this document easy to follow? If not, why?
4. What additions to the document do you think would enhance the structure and subject?
5. What deletions from the document could be made without affecting the overall usefulness?
6. Is there any incorrect or misleading information (what and where)?
7. How would you improve this document?
DS41171B-page 182
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 183 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
PIC16C781/782 PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO.
Device
Device
X
Temperature
Range
/XX
XXX
Package
Pattern
PIC16C781: VDD range 4.0V-5.5V
PIC16C781T: VDD range 4.0V-5.5V (Tape and Reel)
PIC16LC781: VDD range 2.7V-5.5V
PIC16LC781T: VDD range 2.7V-5.5V (Tape and Reel)
Temperature Range
I
=
-40C to +85C
Package
SO
SS
P
JW
Pattern
QTP, SQTP, ROM Code (factory specified) or
Special Requirements . Blank for OTP and
Windowed devices.
=
=
=
=
Examples:
a)
PIC16C781-I/P Industrial Temp.,
Plastic DIP package,
normal VDD limits
b)
PIC16LC781-I/SS Industrial Temp.,
SSOP package,
extended VDD limits
c)
PIC16C781-I/SOT Industrial Temp.,
SOIC package, Tape and Reel,
normal VDD limits
SOIC
SSOP
PDIP
Windowed CERDIP
* JW Devices are UV erasable and can be programmed to any device configuration. JW Devices meet the electrical requirement of
each oscillator type.
Sales and Support
Data Sheets
Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recommended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following:
1.
2.
Your local Microchip sales office
The Microchip Worldwide Site (www.microchip.com)
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 183
PIC16C781.book Page 184 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
NOTES:
DS41171B-page 184
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 185 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
NOTES:
 2001-2013 Microchip Technology Inc.
Preliminary
DS41171B-page 185
PIC16C781.book Page 186 Tuesday, January 29, 2013 3:29 PM
PIC16C781/782
DS41171B-page 186
Preliminary
 2001-2013 Microchip Technology Inc.
PIC16C781.book Page 187 Tuesday, January 29, 2013 3:29 PM
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
•
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device
applications and the like is provided only for your convenience
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
MICROCHIP MAKES NO REPRESENTATIONS OR
WARRANTIES OF ANY KIND WHETHER EXPRESS OR
IMPLIED, WRITTEN OR ORAL, STATUTORY OR
OTHERWISE, RELATED TO THE INFORMATION,
INCLUDING BUT NOT LIMITED TO ITS CONDITION,
QUALITY, PERFORMANCE, MERCHANTABILITY OR
FITNESS FOR PURPOSE. Microchip disclaims all liability
arising from this information and its use. Use of Microchip
devices in life support and/or safety applications is entirely at
the buyer’s risk, and the buyer agrees to defend, indemnify and
hold harmless Microchip from any and all damages, claims,
suits, or expenses resulting from such use. No licenses are
conveyed, implicitly or otherwise, under any Microchip
intellectual property rights.
Trademarks
The Microchip name and logo, the Microchip logo, dsPIC,
FlashFlex, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro,
PICSTART, PIC32 logo, rfPIC, SST, SST Logo, SuperFlash
and UNI/O are registered trademarks of Microchip Technology
Incorporated in the U.S.A. and other countries.
FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor,
MTP, SEEVAL and The Embedded Control Solutions
Company are registered trademarks of Microchip Technology
Incorporated in the U.S.A.
Silicon Storage Technology is a registered trademark of
Microchip Technology Inc. in other countries.
Analog-for-the-Digital Age, Application Maestro, BodyCom,
chipKIT, chipKIT logo, CodeGuard, dsPICDEM,
dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,
ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial
Programming, ICSP, Mindi, MiWi, MPASM, MPF, MPLAB
Certified logo, MPLIB, MPLINK, mTouch, Omniscient Code
Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit,
PICtail, REAL ICE, rfLAB, Select Mode, SQI, Serial Quad I/O,
Total Endurance, TSHARC, UniWinDriver, WiperLock, ZENA
and Z-Scale are trademarks of Microchip Technology
Incorporated in the U.S.A. and other countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
GestIC and ULPP are registered trademarks of Microchip
Technology Germany II GmbH & Co. & KG, a subsidiary of
Microchip Technology Inc., in other countries.
All other trademarks mentioned herein are property of their
respective companies.
© 2001-2013, Microchip Technology Incorporated, Printed in
the U.S.A., All Rights Reserved.
Printed on recycled paper.
ISBN: 9781620769706
QUALITY MANAGEMENT SYSTEM
CERTIFIED BY DNV
== ISO/TS 16949 ==
 2001-2013 Microchip Technology Inc.
Microchip received ISO/TS-16949:2009 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
Preliminary
DS41171B-page 187
PIC16C781.book Page 188 Tuesday, January 29, 2013 3:29 PM
Worldwide Sales and Service
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DS41171B-page 188
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11/29/12
Preliminary
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