MICROCHIP PIC16LF627T

PIC16F62X
FLASH-Based 8-Bit CMOS Microcontrollers
Devices included in this data sheet:
Special Microcontroller Features:
• PIC16F627
• Power-on Reset (POR)
• Power-up Timer (PWRT) and Oscillator Start-up
Timer (OST)
• Brown-out Detect (BOD)
• Watchdog Timer (WDT) with its own on-chip RC
oscillator for reliable operation
• Multiplexed MCLR-pin
• Programmable weak pull-ups on PORTB
• Programmable code protection
• Low voltage programming
• Power saving SLEEP mode
• Selectable oscillator options
- FLASH configuration bits for oscillator options
- ER (External Resistor) oscillator
- Reduced part count
- Dual speed INTRC
- Lower current consumption
- EC External Clock input
- XT oscillator mode
- HS oscillator mode
- LP oscillator mode
• Serial in-circuit programming (via two pins)
• Four user programmable ID locations
• PIC16F628
Referred to collectively as PIC16F62X .
High Performance RISC CPU:
• Only 35 instructions to learn
• All single-cycle instructions (200 ns), except for
program branches which are two-cycle
• Operating speed:
- DC - 20 MHz clock input
- DC - 200 ns instruction cycle
Memory
Device
FLASH
Program
RAM
Data
EEPROM
Data
PIC16F627
1024 x 14
224 x 8
128 x 8
PIC16F628
2048 x 14
224 x 8
128 x 8
•
•
•
•
Interrupt capability
16 special function hardware registers
8-level deep hardware stack
Direct, Indirect and Relative addressing modes
Peripheral Features:
• 15 I/O pins with individual direction control
• High current sink/source for direct LED drive
• Analog comparator module with:
- Two analog comparators
- Programmable on-chip voltage reference
(VREF) module
- Programmable input multiplexing from device
inputs and internal voltage reference
- Comparator outputs are externally accessible
• Timer0: 8-bit timer/counter with 8-bit
programmable prescaler
• Timer1: 16-bit timer/counter with external crystal/
clock capability
• Timer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler
• Capture, Compare, PWM (CCP) module
- Capture is 16-bit, max. resolution is 12.5 ns
- Compare is 16-bit, max. resolution is 200 ns
- PWM max. resolution is 10-bit
• Universal Synchronous/Asynchronous Receiver/
Transmitter USART/SCI
• 16 Bytes of common RAM
 1999 Microchip Technology Inc.
CMOS Technology:
• Low-power, high-speed CMOS FLASH technology
• Fully static design
• Wide operating voltage range
- PIC16F627 - 3.0V to 5.5V
- PIC16F628 - 3.0V to 5.5V
- PIC16LF627 - 2.0V to 5.5V
- PIC16LF628 - 2.0V to 5.5V
• Commercial, industrial and extended temperature
range
• Low power consumption
- < 2.0 mA @ 5.0V, 4.0 MHz
- 15 µA typical @ 3.0V, 32 kHz
- < 1.0 µA typical standby current @ 3.0V
Preliminary
DS40300B-page 1
PIC16F62X
Pin Diagrams
PDIP, SOIC
•1
2
3
4
5
6
7
8
9
PIC16F62X
RA2/AN2/VREF
RA3/AN3/CMP1
RA4/TOCKI/CMP2
RA5/MCLR/THV
VSS
RB0/INT
RB1/RX/DT
RB2/TX/CK
RB3/CCP1
18
17
16
15
14
13
12
11
10
RA1/AN1
RA0/AN0
RA7/OSC1/CLKIN
RA6/OSC2/CLKOUT
VDD
RB7/T1OSI
RB6/T1OSO/T1CKI
RB5
RB4/PGM
SSOP
RB0/INT
RB1/RX/DT
RB2/TX/CK
RB3/CCP1
•1
2
3
4
5
6
7
8
9
10
PIC16F62X
RA2/AN2/VREF
RA3/AN3/CMP1
RA4/TOCKI/CMP2
RA5/MCLR/THV
VSS
VSS
20
19
18
17
16
15
14
13
12
11
RA1/AN1
RA0/AN0
RA7/OSC1/CLKIN
RA6/OSC2/CLKOUT
VDD
VDD
RB7/T1OSI
RB6/T1OSO/T1CKI
RB5
RB4/PGM
Device Differences
Device
Voltage
Range
Oscillator
Process
Technology
(Microns)
PIC16F627
3.0 - 5.5
See Note 1
0.7
PIC16F628
3.0 - 5.5
See Note 1
0.7
PIC16LF627
2.0 - 5.5
See Note 1
0.7
PIC16LF628
2.0 - 5.5
See Note 1
0.7
Note 1: If you change from this device to another device, please verify oscillator characteristics in your application.
DS40300B-page 2
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
Table of Contents
1.0
General Description..................................................................................................................................................................... 5
2.0
PIC16F62X Device Varieties...................................................................................................................................................... 7
3.0
Architectural Overview ................................................................................................................................................................ 9
4.0
Memory Organization ................................................................................................................................................................ 13
5.0
I/O Ports .................................................................................................................................................................................... 27
6.0
Timer0 Module .......................................................................................................................................................................... 45
7.0
Timer1 Module .......................................................................................................................................................................... 50
8.0
Timer2 Module .......................................................................................................................................................................... 54
9.0
Comparator Module................................................................................................................................................................... 57
10.0 Capture/Compare/PWM (CCP) Module .................................................................................................................................... 63
11.0 Voltage Reference Module........................................................................................................................................................ 69
12.0 Universal Synchronous Asynchronous Receiver Transmitter (USART).................................................................................... 71
13.0 Data EEPROM Memory ............................................................................................................................................................ 91
14.0 Special Features of the CPU..................................................................................................................................................... 95
15.0 Instruction Set Summary ......................................................................................................................................................... 113
16.0 Development Support.............................................................................................................................................................. 125
17.0 Electrical Specifications........................................................................................................................................................... 131
18.0 Device Characterization Information ....................................................................................................................................... 145
19.0 Packaging Information............................................................................................................................................................. 147
Index .................................................................................................................................................................................................. 151
On-Line Support................................................................................................................................................................................. 155
Reader Response .............................................................................................................................................................................. 156
PIC16F62X Product Identification System ........................................................................................................................................ 157
To Our Valued Customers
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An errata sheet may exist for current devices, describing minor operational differences (from the data sheet) and recommended
workarounds. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision of silicon and revision of document to which it applies.
To determine if an errata sheet exists for a particular device, please check with one of the following:
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When contacting a sales office or the literature center, please specify which device, revision of silicon and data sheet (include literature number) you are using.
Corrections to this Data Sheet
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We appreciate your assistance in making this a better document.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 3
PIC16F62X
NOTES:
DS40300B-page 4
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
1.0
GENERAL DESCRIPTION
1.1
The PIC16F62X are 18-Pin FLASH-based members of
the versatile PIC16CXX family of low-cost,
high-performance,
CMOS,
fully-static,
8-bit
microcontrollers.
All PICmicro® microcontrollers employ an advanced
RISC architecture. The PIC16F62X have enhanced
core features, eight-level deep stack, and multiple internal and external interrupt sources. The separate
instruction and data buses of the Harvard architecture
allow a 14-bit wide instruction word with the separate
8-bit wide data. The two-stage instruction pipeline
allows all instructions to execute in a single-cycle,
except for program branches (which require two
cycles). A total of 35 instructions (reduced instruction
set) are available. Additionally, a large register set gives
some of the architectural innovations used to achieve a
very high performance.
Development Support
The PIC16F62X family is supported by a full-featured
macro assembler, a software simulator, an in-circuit
emulator, a low-cost development programmer and a
full-featured programmer. A Third Party “C” compiler
support tool is also available.
PIC16F62X microcontrollers typically achieve a 2:1
code compression and a 4:1 speed improvement over
other 8-bit microcontrollers in their class.
PIC16F62X devices have special features to reduce
external components, thus reducing system cost,
enhancing system reliability and reducing power consumption. There are eight oscillator configurations, of
which the single pin ER oscillator provides a low-cost
solution. The LP oscillator minimizes power consumption, XT is a standard crystal, INTRC is a self-contained
internal oscillator and the HS is for High Speed crystals. The SLEEP (power-down) mode offers power savings. The user can wake up the chip from SLEEP
through several external and internal interrupts and
reset.
A highly reliable Watchdog Timer with its own on-chip
RC oscillator provides protection against software
lock- up.
Table 1-1 shows the features of the PIC16F62X
mid-range microcontroller families.
A simplified block diagram of the PIC16F62X is shown
in Figure 3-1.
The PIC16F62X series fits in applications ranging from
battery chargers to low-power remote sensors. The
FLASH technology makes customization of application
programs (detection levels, pulse generation, timers,
etc.) extremely fast and convenient. The small footprint
packages make this microcontroller series ideal for all
applications with space limitations. Low-cost,
low-power, high-performance, ease of use and I/O flexibility make the PIC16F62X very versatile.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 5
PIC16F62X
TABLE 1-1:
PIC16F62X FAMILY OF DEVICES
PIC16F627
Clock
Memory
Peripherals
Features
Maximum Frequency
of Operation (MHz)
20
PIC16F628
PIC16LF627
PIC16LF628
20
20
20
FLASH Program Memory (words) 1024
2048
1024
2048
RAM Data Memory (bytes)
224
224
224
224
EEPROM Data Memory (bytes)
128
128
128
128
Timer Module(s)
TMR0, TMR1, TMR2 TMR0, TMR1, TMR2
TMR0, TMR1, TMR2
TMR0, TMR1, TMR2
Comparators(s)
2
2
2
2
Capture/Compare/PWM modules 1
1
1
1
Serial Communications
USART
USART
USART
USART
Internal Voltage Reference
Yes
Yes
Yes
Yes
Interrupt Sources
10
10
10
10
I/O Pins
16
16
16
16
Voltage Range (Volts)
3.0-5.5
3.0-5.5
2.0-5.5
2.0-5.5
Brown-out Detect
Yes
Yes
Yes
Yes
Packages
18-pin DIP,
SOIC;
20-pin SSOP
18-pin DIP,
SOIC;
20-pin SSOP
18-pin DIP,
SOIC;
20-pin SSOP
18-pin DIP,
SOIC;
20-pin SSOP
All PICmicro® Family devices have Power-on Reset, selectable Watchdog Timer, selectable code protect and high I/O current
capability. All PIC16F62X Family devices use serial programming with clock pin RB6 and data pin RB7.
DS40300B-page 6
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
2.0
PIC16F62X DEVICE VARIETIES
A variety of frequency ranges and packaging options are
available. Depending on application and production
requirements the proper device option can be selected
using the information in the PIC16F62X Product
Identification System section at the end of this data
sheet. When placing orders, please use this page of the
data sheet to specify the correct part number.
2.1
Flash Devices
These devices are offered in the lower cost plastic
package, even though the device can be erased and
reprogrammed. This allows the same device to be used
for prototype development and pilot programs as well
as production.
A further advantage of the electrically-erasable Flash
version is that it can be erased and reprogrammed
in-circuit, or by device programmers, such as
Microchip’s PICSTART® Plus or PRO MATE® II
programmers.
2.2
Quick-Turnaround-Production (QTP)
Devices
Microchip offers a QTP Programming Service for
factory production orders. This service is made
available for users who chose not to program a medium
to high quantity of units and whose code patterns have
stabilized. The devices are standard FLASH devices
but with all program locations and configuration options
already programmed by the factory. Certain code and
prototype verification procedures apply before
production shipments are available. Please contact
your Microchip Technology sales office for more details.
2.3
Serialized
Quick-Turnaround-Production
(SQTPSM) Devices
Microchip offers a unique programming service where
a few user-defined locations in each device are
programmed with different serial numbers. The serial
numbers may be random, pseudo-random or
sequential.
Serial programming allows each device to have a
unique number which can serve as an entry-code,
password or ID number.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 7
PIC16F62X
NOTES:
DS40300B-page 8
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
3.0
ARCHITECTURAL OVERVIEW
The high performance of the PIC16F62X family can be
attributed to a number of architectural features
commonly found in RISC microprocessors. To begin
with, the PIC16F62X uses a Harvard architecture, in
which, program and data are accessed from separate
memories using separate busses. This improves
bandwidth over traditional von Neumann architecture
where program and data are fetched from the same
memory. Separating program and data memory further
allows instructions to be sized differently than 8-bit wide
data word. Instruction opcodes are 14-bits wide making
it possible to have all single word instructions. A 14-bit
wide program memory access bus fetches a 14-bit
instruction in a single cycle. A two-stage pipeline overlaps fetch and execution of instructions. Consequently,
all instructions (35) execute in a single-cycle (200 ns @
20 MHz) except for program branches.
The Table below lists program memory (Flash, Data
and EEPROM).
Memory
Device
FLASH
Program
RAM
Data
EEPROM
Data
PIC16F627
1024 x 14
224 x 8
128 x 8
PIC16F628
2048 x 14
224 x 8
128 x 8
PIC16LF627
1024 x 14
224 x 8
128 x 8
PIC16LF628
2048 x 14
224 x 8
128 x 8
The PIC16F62X can directly or indirectly address its
register files or data memory. All special function
registers including the program counter are mapped in
the data memory. The PIC16F62X have an orthogonal
(symmetrical) instruction set that makes it possible to
carry out any operation on any register using any
addressing mode. This symmetrical nature and lack of
‘special optimal situations’ make programming with the
PIC16F62X simple yet efficient. In addition, the
learning curve is reduced significantly.
 1999 Microchip Technology Inc.
The PIC16F62X devices contain an 8-bit ALU and
working register. The ALU is a general purpose
arithmetic unit. It performs arithmetic and Boolean
functions between data in the working register and any
register file.
The ALU is 8-bit wide and capable of addition,
subtraction, shift and logical operations. Unless
otherwise mentioned, arithmetic operations are two's
complement in nature. In two-operand instructions,
typically one operand is the working register
(W register). The other operand is a file register or an
immediate constant. In single operand instructions, the
operand is either the W register or a file register.
The W register is an 8-bit working register used for ALU
operations. It is not an addressable register.
Depending on the instruction executed, the ALU may
affect the values of the Carry (C), Digit Carry (DC), and
Zero (Z) bits in the STATUS register. The C and DC bits
operate as a Borrow and Digit Borrow out bit,
respectively, bit in subtraction. See the SUBLW and
SUBWF instructions for examples.
A simplified block diagram is shown in Figure 3-1, with
a description of the device pins in Table 3-1.
Two types of data memory are provided on the
PIC16F62X devices. Non-volatile EEPROM data
memory is provided for long term storage of data such
as calibration values, look up table data, and any other
data which may require periodic updating in the field.
This data is not lost when power is removed. The other
data memory provided is regular RAM data memory.
Regular RAM data memory is provided for temporary
storage of data during normal operation. It is lost when
power is removed.
Preliminary
DS40300B-page 9
PIC16F62X
FIGURE 3-1:
BLOCK DIAGRAM
13
Program
Memory
14
Data EEPROM
RAM
File
Registers
8 Level Stack
(13-bit)
Program
Bus
8
Data Bus
Program Counter
FLASH
RAM Addr (1)
PORTA
9
Addr MUX
Instruction reg
7
Direct Addr
8
RA0/AN0
RA1/AN1
RA2/AN2/VREF
RA3/AN3/CMP1
RA4/T0CK1/CMP2
RA5/MCLR/THV
RA6/OSC2/CLKOUT
RA7/OSC1/CLKIN
Indirect
Addr
FSR reg
STATUS reg
8
3
Power-up
Timer
Instruction
Decode &
Control
Oscillator
Start-up Timer
Power-on
Reset
Timing
Generation
PORTB
RB0/INT
RB1/RX/DT
RB2/TX/CK
RB3/CCP1
RB4/PGM
RB5
RB6/T1OSO/T1CKI
RB7/T1OSI
ALU
8
Watchdog
Timer
Brown-out
Detect
OSC1/CLKIN
OSC2/CLKOUT
MUX
W reg
Low-Voltage
Programming
MCLR
Comparator
Timer0
VREF
CCP1
VDD, VSS
Timer1
Timer2
USART
Memory
Device
FLASH
Program
RAM
Data
EEPROM
Data
PIC16F627
1024 x 14
224 x 8
128 x 8
PIC16F628
2048 x 14
224 x 8
128 x 8
PIC16LF627
1024 x 14
224 x 8
128 x 8
PIC16LF628
2048 x 14
224 x 8
128 x 8
Note 1: Higher order bits are from the STATUS register.
DS40300B-page 10
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
TABLE 3-1:
PIC16F62X PINOUT DESCRIPTION
DIP/
SOIC
Pin #
SSOP
Pin #
I/O/P
Type
Buffer
Type
RA0/AN0
17
19
I/O
ST
Bi-directional I/O port/Analog comparator input
RA1/AN1
18
20
I/O
ST
Bi-directional I/O port/Analog comparator input
RA2/AN2/VREF
1
1
I/O
ST
Bi-directional I/O port/Analog comparator input/VREF output
RA3/AN3/CMP1
2
2
I/O
ST
Bi-directional I/O port/Analog comparator input/comparator output
RA4/T0CKI/CMP2
3
3
I/O
ST
Bi-directional I/O port/Can be configured as T0CKI/comparator output
RA5/MCLR/THV
4
4
I
ST
Input port/master clear (reset input/programming voltage
input. When configured as MCLR, this pin is an active low
reset to the device. Voltage on MCLR/THV must not
exceed VDD during normal device operation.
RA6/OSC2/CLKOUT
15
17
I/O
ST
Bi-directional I/O port/Oscillator crystal output. Connects
to crystal or resonator in crystal oscillator mode. In ER
mode, OSC2 pin outputs CLKOUT which has 1/4 the frequency of OSC1, and denotes the instruction cycle rate.
RA7/OSC1/CLKIN
16
18
I/O
ST
Bi-directional I/O port/Oscillator crystal input/external
clock source input. ER biasing pin.
RB0/INT
6
7
I/O
TTL/ST(1)
Bi-directional I/O port/external interrupt. Can be software
programmed for internal weak pull-up.
RB1/RX/DT
7
8
I/O
TTL/ST(3)
Bi-directional I/O port/ USART receive pin/synchronous
data I/O. Can be software programmed for internal weak
pull-up.
RB2/TX/CK
8
9
I/O
TTL/ST(3)
Bi-directional I/O port/ USART transmit pin/synchronous
clock I/O. Can be software programmed for internal weak
pull-up.
RB3/CCP1
9
10
I/O
TTL/ST(4)
Bi-directional I/O port/Capture/Compare/PWM I/O. Can
be software programmed for internal weak pull-up.
RB4/PGM
10
11
I/O
TTL/ST(5)
Bi-directional I/O port/Low voltage programming input pin.
Wake-up from SLEEP on pin change. Can be software
programmed for internal weak pull-up. When low voltage
programming is enabled, the interrupt on pin change and
weak pull-up resistor are disabled.
RB5
11
12
I/O
TTL
Bi-directional I/O port/Wake-up from SLEEP on pin
change. Can be software programmed for internal weak
pull-up.
RB6/T1OSO/T1CKI
12
13
I/O
TTL/ST(2)
Bi-directional I/O port/Timer1 oscillator output/Timer1
clock input. Wake up from SLEEP on pin change. Can be
software programmed for internal weak pull-up.
RB7/T1OSI
13
14
I/O
TTL/ST(2)
Bi-directional I/O port/Timer1 oscillator input. Wake up
from SLEEP on pin change. Can be software programmed
for internal weak pull-up.
Name
Description
VSS
5
5,6
P
—
Ground reference for logic and I/O pins.
VDD
14
15,16
P
—
Positive supply for logic and I/O pins.
Legend:
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
O = output
I/O = input/output
P = power
— = Not used
I = Input
ST = Schmitt Trigger input
TTL = TTL input
I/OD =input/open drain output
This buffer is a Schmitt Trigger input when configured as the external interrupt.
This buffer is a Schmitt Trigger input when used in serial programming mode.
This buffer is a Schmitt Trigger I/O when used in USART/Synchronous mode.
This buffer is a Schmitt Trigger I/O when used in CCP mode.
This buffer is a Schmitt Trigger input when used in low voltage program mode.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 11
PIC16F62X
3.1
Clocking Scheme/Instruction Cycle
3.2
The clock input (OSC1/CLKIN/RA7 pin) is internally
divided by four to generate four non-overlapping
quadrature clocks namely Q1, Q2, Q3 and Q4. Internally, the program counter (PC) is incremented every
Q1, the instruction is fetched from the program memory
and latched into the instruction register in Q4. The
instruction is decoded and executed during the
following Q1 through Q4. The clocks and instruction
execution flow is shown in Figure 3-2.
Instruction Flow/Pipelining
An “Instruction Cycle” consists of four Q cycles (Q1,
Q2, Q3 and Q4). The instruction fetch and execute are
pipelined such that fetch takes one instruction cycle
while decode and execute takes another instruction
cycle. However, due to the pipelining, each instruction
effectively executes in one cycle. If an instruction
causes the program counter to change (e.g., GOTO)
then two cycles are required to complete the instruction
(Example 3-1).
A fetch cycle begins with the program counter (PC)
incrementing in Q1.
In the execution cycle, the fetched instruction is latched
into the “Instruction Register (IR)” in cycle Q1. This
instruction is then decoded and executed during the
Q2, Q3, and Q4 cycles. Data memory is read during Q2
(operand read) and written during Q4 (destination
write).
FIGURE 3-2:
CLOCK/INSTRUCTION CYCLE
Q1
Q2
Q3
Q4
Q2
Q1
Q3
Q4
Q1
Q2
Q3
Q4
OSC1
Q1
Q2
Internal
phase
clock
Q3
Q4
PC
OSC2/CLKOUT
(ER mode)
EXAMPLE 3-1:
PC
PC+1
Fetch INST (PC)
Execute INST (PC-1)
PC+2
Fetch INST (PC+1)
Execute INST (PC)
Fetch INST (PC+2)
Execute INST (PC+1)
INSTRUCTION PIPELINE FLOW
1. MOVLW 55h
2. MOVWF PORTB
3. CALL
SUB_1
4. BSF
PORTA, BIT3
Fetch 1
Execute 1
Fetch 2
Execute 2
Fetch 3
Execute 3
Fetch 4
Flush
Fetch SUB_1 Execute SUB_1
All instructions are single cycle, except for any program branches. These take two cycles since the fetch
instruction is “flushed” from the pipeline while the new instruction is being fetched and then executed.
DS40300B-page 12
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
4.0
MEMORY ORGANIZATION
4.1
Program Memory Organization
FIGURE 4-2: PROGRAM MEMORY MAP AND
STACK FOR THE PIC16F628
PC<12:0>
The PIC16F62X has a 13-bit program counter capable
of addressing an 8K x 14 program memory space. Only
the first 1K x 14 (0000h - 03FFh) for the PIC16F627
and 2K x 14 (0000h - 07FFh) for the PIC16F628 are
physically implemented. Accessing a location above
these boundaries will cause a wrap-around within the
first 1K x 14 space (PIC16F627) or 2K x 14 space
(PIC16F628). The reset vector is at 0000h and the
interrupt vector is at 0004h (Figure 4-1 and Figure 4-2).
FIGURE 4-1:
CALL, RETURN
RETFIE, RETLW
Stack Level 1
Stack Level 2
Stack Level 8
PROGRAM MEMORY MAP
AND STACK FOR THE
PIC16F627
PC<12:0>
CALL, RETURN
RETFIE, RETLW
13
Reset Vector
000h
Interrupt Vector
0004
0005
13
On-chip Program
Memory
Stack Level 1
Stack Level 2
07FFh
0800h
Stack Level 8
Reset Vector
1FFFh
000h
4.2
Interrupt Vector
0004
0005
On-chip Program
Memory
03FFh
0400h
Data Memory Organization
The data memory (Figure 4-3) is partitioned into four
Banks which contain the general purpose registers and
the special function registers. The Special Function
Registers are located in the first 32 locations of each
Bank. Register locations 20-7Fh, A0h-FFh, 120h-14Fh,
170h-17Fh and 1F0h-1FFh are general purpose registers implemented as static RAM.
The Table below lists how to access the four banks of
registers:
RP1
RP0
Bank0
0
0
Bank1
0
1
Bank2
1
0
Bank3
1
1
1FFFh
Addresses F0h-FFh, 170h-17Fh and 1F0h-1FFh are
implemented as common RAM and mapped back to
addresses 70h-7Fh.
4.2.1
GENERAL PURPOSE REGISTER FILE
The register file is organized as 224 x 8 in the
PIC16F62X. Each is accessed either directly or indirectly through the File Select Register FSR
(Section 4.4).
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 13
PIC16F62X
FIGURE 4-3:
DATA MEMORY MAP OF THE PIC16F627 AND PIC16F628
File
Address
Indirect addr.(*)
00h
Indirect addr.(*)
80h
Indirect addr.(*)
100h
Indirect addr.(*)
180h
TMR0
01h
OPTION
81h
TMR0
101h
OPTION
181h
PCL
02h
PCL
82h
PCL
102h
PCL
182h
STATUS
03h
STATUS
83h
STATUS
103h
STATUS
183h
FSR
04h
84h
FSR
104h
FSR
184h
PORTA
05h
TRISA
85h
PORTB
06h
TRISB
86h
FSR
PORTB
185h
TRISB
186h
87h
107h
187h
08h
88h
108h
188h
09h
89h
109h
0Ah
INTCON
0Bh
PIR1
0Ch
PCLATH
INTCON
PIE1
0Dh
PCLATH
10Ah
PCLATH
18Ah
8Bh
INTCON
10Bh
INTCON
18Bh
8Ch
10Ch
18Ch
8Dh
10Dh
18Dh
8Eh
10Eh
18Eh
10Fh
18Fh
0Eh
TMR1H
0Fh
8Fh
T1CON
10h
90h
TMR2
11h
91h
T2CON
12h
PCON
PR2
92h
13h
93h
14h
94h
CCPR1L
15h
95h
CCPR1H
16h
96h
CCP1CON
17h
RCSTA
18h
TXSTA
98h
TXREG
19h
RCREG
SPBRG
EEDATA
99h
1Ah
1Bh
EEADR
9Bh
1Ch
EECON1
9Ch
1Dh
EECON2*
9Dh
97h
1Eh
1Fh
20h
189h
8Ah
TMR1L
9Ah
9Eh
VRCON
General
Purpose
Register
80 Bytes
9Fh
A0h
General
Purpose
Register
48 Bytes
General
Purpose
Register
96 Bytes
accesses
70h-7Fh
7Fh
Bank 0
106h
07h
PCLATH
CMCON
105h
EFh
F0h
accesses
70h-7Fh
14Fh
150h
16Fh
170h
1EFh
1F0h
accesses
70h - 7Fh
17Fh
FFh
Bank 2
Bank 1
11Fh
120h
1FFh
Bank 3
Unimplemented data memory locations, read as ’0’.
* Not a physical register.
DS40300B-page 14
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
4.2.2
SPECIAL FUNCTION REGISTERS
The special registers can be classified into two sets
(core and peripheral). The special function registers
associated with the “core” functions are described in
this section. Those related to the operation of the
peripheral features are described in the section of that
peripheral feature.
The special function registers are registers used by the
CPU and Peripheral functions for controlling the
desired operation of the device (Table 4-1). These
registers are static RAM.
TABLE 4-1:
Address
SPECIAL REGISTERS SUMMARY BANK0
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Value on
all other
Value on
POR
Reset
Bit 0
Resets(1)
Bank 0
00h
INDF
Addressing this location uses contents of FSR to address data memory (not a physical register)
xxxx xxxx
xxxx xxxx
01h
TMR0
Timer0 Module’s Register
xxxx xxxx
uuuu uuuu
02h
PCL
Program Counter's (PC) Least Significant Byte
03h
STATUS
IRP
04h
FSR
05h
PORTA
06h
07h
PORTB
Unimplemented
08h
09h
Unimplemented
Unimplemented
0000 0000
0000 0000
PD
Z
DC
C
0001 1xxx
000q quuu
Indirect data memory address pointer
RA7
RA6
RA5
RA4
RA3
RA2
RA1
RA0
xxxx xxxx
xxxx 0000
uuuu uuuu
xxxx 0000
RB7
RB3
RB2
RB1
RB0
xxxx xxxx
—
uuuu uuuu
—
—
—
—
—
---0 0000
---0 0000
RP0
RP1
RB6
—
TO
RB5
—
RB4
0Ah
PCLATH
0Bh
INTCON
GIE
PEIE
T0IE
—
INTE
Write buffer for upper 5 bits of program counter
0Ch
0Dh
PIR1
Unimplemented
EEIF
CMIF
RCIF
TXIF
0Eh
TMR1L
0Fh
TMR1H
10h
11h
T1CON
TMR2
12h
13h
T2CON
Unimplemented
T0IF
INTF
RBIF
0000 000x
0000 000u
CCP1IF
TMR2IF
TMR1IF
0000 -000
—
0000 -000
—
Holding register for the least significant byte of the 16-bit TMR1
xxxx xxxx
uuuu uuuu
Holding register for the most significant byte of the 16-bit TMR1
xxxx xxxx
uuuu uuuu
--00 0000
--uu uuuu
0000 0000
0000 0000
-000 0000
—
-uuu uuuu
—
—
—
T1CKPS1
T1CKPS0
RBIE
—
T1OSCEN
T1SYNC
TMR1CS
TMR2 module’s register
—
TOUTPS3
TOUTPS2
TOUTPS1
TOUTPS0
TMR2ON
T2CKPS1 T2CKPS0
14h
Unimplemented
15h
CCPR1L
Capture/Compare/PWM register (LSB)
16h
CCPR1H
17h
CCP1CON
Capture/Compare/PWM register (MSB)
—
—
CCP1X
CCP1Y
CCP1M3
CCP1M2
CCP1M1
18h
RCSTA
SPEN
ADEN
FERR
OERR
19h
TXREG
USART Transmit data register
1Ah
1Bh
RCREG
Unimplemented
USART Receive data register
1Ch
1Dh
Unimplemented
Unimplemented
1Eh
Unimplemented
1Fh
CMCON
TMR1ON
C2OUT
RX9
C1OUT
SREN
C2INV
CREN
C1INV
CIS
CM2
CM1
—
—
xxxx xxxx
uuuu uuuu
CCP1M0
xxxx xxxx
--00 0000
uuuu uuuu
--00 0000
RX9D
0000 -00x
0000 -00x
0000 0000
0000 0000
0000 0000
—
0000 0000
—
—
—
—
—
—
0000 0000
—
0000 0000
CM0
Legend: — = Unimplemented locations read as ‘0’, u = unchanged, x = unknown, q = value depends on condition,
shaded = unimplemented
Note 1: Other (non power-up) resets include MCLR Reset, Brown-out Detect and Watchdog Timer Reset during
normal operation.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 15
PIC16F62X
TABLE 4-2:
Address
SPECIAL FUNCTION REGISTERS SUMMARY BANK1
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Reset
Value on
all other
resets(1)
Bank 1
80h
INDF
Addressing this location uses contents of FSR to address data memory (not a physical reg- xxxx xxxx
ister)
xxxx xxxx
81h
82h
OPTION
PCL
INTEDG
T0CS
T0SE
PSA
RBPU
Program Counter’s (PC) Least Significant Byte
1111 1111
83h
84h
STATUS
FSR
IRP
RP1
RP0
TO
Indirect data memory address pointer
85h
86h
TRISA
TRISB
TRISA7
TRISB7
87h
Unimplemented
—
—
88h
Unimplemented
—
—
89h
Unimplemented
—
8Ah
PCLATH
TRISA6
TRISB6
—
—
—
TRISB5
—
PS2
PS1
PS0
1111 1111
0000 0000
0000 0000
0001 1xxx
000q quuu
PD
Z
DC
C
xxxx xxxx
uuuu uuuu
TRISA4
TRISA3
TRISA2
TRISA1
TRISA0
11-1 1111
11-1 1111
TRISB4
TRISB3
TRISB2
TRISB1
TRISB0
1111 1111
1111 1111
—
Write buffer for upper 5 bits of program counter
---0 0000
---0 0000
8Bh
INTCON
GIE
PEIE
T0IE
INTE
8Ch
PIE1
EEIE
CMIE
RCIE
TXIE
RBIE
—
T0IF
CCP1IE
INTF
TMR2IE
RBIF
TMR1IE
0000 000x
0000 -000
0000 000u
0000 -000
POR
BOD
—
---- 1-0x
—
---- 1-uq
8Dh
Unimplemented
8Eh
PCON
8Fh
90h
Unimplemented
Unimplemented
—
91h
Unimplemented
—
92h
PR2
93h
94h
Unimplemented
Unimplemented
—
—
—
—
95h
96h
Unimplemented
Unimplemented
—
—
—
—
—
—
—
—
OSCF
—
Timer2 Period Register
11111111
97h
Unimplemented
98h
TXSTA
CSRC
99h
SPBRG
9Ah
EEDATA
9Bh
9Ch
EEADR
EECON1
9Dh
9Eh
EECON2
Unimplemented
EEPROM control register 2 (not a physical register)
9Fh
VRCON
VREN
—
—
11111111
—
0000 -010
—
0000 -010
Baud Rate Generator Register
0000 0000
0000 0000
EEPROM data register
xxxx xxxx
uuuu uuuu
xxxx xxxx
---- x000
uuuu uuuu
---- q000
-------—
-------—
000- 0000
000- 0000
—
—
TX9
TXEN
SYNC
EEPROM address register
—
—
—
VROE
VRR
—
—
WRERR
VR3
BRGH
WREN
VR2
TRMT
WR
VR1
TX9D
RD
VR0
Legend: : — = Unimplemented locations read as ‘0’, u = unchanged, x = unknown, q = value depends on condition,
shaded = unimplemented
Note 1: Other (non power-up) resets include MCLR Reset, Brown-out Detect and Watchdog Timer Reset during
normal operation.
DS40300B-page 16
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
TABLE 4-3:
Address
SPECIAL FUNCTION REGISTERS SUMMARY BANK2
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Reset
Value on
all other
resets(1)
Bank 1
100h
INDF
Addressing this location uses contents of FSR to address data memory (not a physical reg- xxxx xxxx
ister)
xxxx xxxx
101h
102h
TMR0
PCL
INTEDG
T0CS
T0SE
PSA
RBPU
Program Counter’s (PC) Least Significant Byte
1111 1111
103h
104h
STATUS
FSR
IRP
RP1
RP0
TO
Indirect data memory address pointer
105h
106h
Unimplemented
107h
Unimplemented
—
—
108h
Unimplemented
—
—
109h
Unimplemented
—
10Ah
PCLATH
10Bh
10Ch
INTCON
10Dh
10Eh
Unimplemented
10Fh
110h
PORTB
PD
PS2
Z
PS1
DC
PS0
C
1111 1111
0000 0000
0000 0000
0001 1xxx
000q quuu
xxxx xxxx
uuuu uuuu
—
TRISB7
—
GIE
TRISB6
—
PEIE
TRISB5
—
T0IE
TRISB4
TRISB3
TRISB2
TRISB1
TRISB0
1111 1111
—
1111 1111
—
Write buffer for upper 5 bits of program counter
---0 0000
---0 0000
INTE
0000 000x
—
0000 000u
—
RBIE
T0IF
INTF
RBIF
—
—
—
—
Unimplemented
Unimplemented
—
—
111h
112h
Unimplemented
—
—
113h
114h
Unimplemented
Unimplemented
—
—
—
—
115h
116h
Unimplemented
Unimplemented
—
—
—
—
117h
Unimplemented
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
118h
119h
11Ah
11Bh
11Ch
11Dh
11Eh
Unimplemented
11Fh
Legend: — = Unimplemented locations read as ‘0’, u = unchanged, x = unknown, q = value depends on condition,
shaded = unimplemented
Note 1: Other (non power-up) resets include MCLR Reset, Brown-out Detect and Watchdog Timer Reset during
normal operation.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 17
PIC16F62X
TABLE 4-4:
Address
SPECIAL FUNCTION REGISTERS SUMMARY BANK3
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Reset
Value on
all other
resets(1)
Bank 1
180h
INDF
Addressing this location uses contents of FSR to address data memory (not a physical reg- xxxx xxxx
ister)
xxxx xxxx
181h
182h
OPTION
PCL
INTEDG
T0CS
T0SE
PSA
RBPU
Program Counter’s (PC) Least Significant Byte
1111 1111
183h
184h
STATUS
FSR
IRP
RP1
RP0
TO
Indirect data memory address pointer
185h
Unimplemented
186h
TRISB
187h
Unimplemented
—
—
188h
Unimplemented
—
—
189h
Unimplemented
—
18Ah
PCLATH
18Bh
INTCON
PD
PS2
Z
PS1
DC
PS0
C
1111 1111
0000 0000
0000 0000
0001 1xxx
000q quuu
xxxx xxxx
uuuu uuuu
—
TRISB7
—
GIE
TRISB6
—
PEIE
TRISB5
—
T0IE
TRISB4
TRISB3
TRISB2
TRISB1
TRISB0
1111 1111
—
1111 1111
—
Write buffer for upper 5 bits of program counter
---0 0000
---0 0000
INTE
0000 000x
0000 000u
RBIE
T0IF
INTF
RBIF
18Ch
18Dh
18Eh
18Fh
190h
191h
192h
193h
194h
195h
196h
197h
198h
199h
19Ah
19Bh
19Ch
19Dh
19Eh
19Fh
Legend: — = Unimplemented locations read as ‘0’, u = unchanged, x = unknown, q = value depends on condition,
shaded = unimplemented
Note 1: Other (non power-up) resets include MCLR Reset, Brown-out Detect and Watchdog Timer Reset during
normal operation.
DS40300B-page 18
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
4.2.2.1
STATUS REGISTER
The STATUS register, shown in Register 4-1, contains
the arithmetic status of the ALU, the RESET status and
the bank select bits for data memory (SRAM).
The STATUS register can be the destination for any
instruction, like any other register. If the STATUS
register is the destination for an instruction that affects
the Z, DC or C bits, then the write to these three bits is
disabled. These bits are set or cleared according to the
device logic. Furthermore, the TO and PD bits are not
writable. Therefore, the result of an instruction with the
STATUS register as destination may be different than
intended.
It is recommended, therefore, that only BCF, BSF,
SWAPF and MOVWF instructions are used to alter the
STATUS register because these instructions do not
affect any status bit. For other instructions, not affecting
any status bits, see the “Instruction Set Summary”.
Note 1:
The C and DC bits operate as a Borrow
and Digit Borrow out bit, respectively, in
subtraction. See the SUBLW and SUBWF
instructions for examples.
For example, CLRF STATUS will clear the upper-three
bits and set the Z bit. This leaves the status register as
000uu1uu (where u = unchanged).
REGISTER 4-1: STATUS REGISTER (ADDRESS 03H OR 83H)
R/W-0
IRP
bit7
bit 7:
R/W-0
RP1
R/W-0
RP0
R-1
TO
R-1
PD
R/W-x
Z
R/W-x
DC
R/W-x
C
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit,
read as ’0’
-n = Value at POR reset
-x = Unknown at POR reset
IRP: Register Bank Select bit (used for indirect addressing)
1 = Bank 2, 3 (100h - 1FFh)
0 = Bank 0, 1 (00h - FFh)
bit 6-5: RP1:RP0: 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)
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.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 19
PIC16F62X
4.2.2.2
OPTION REGISTER
The OPTION register is a readable and writable
register which contains various control bits to configure
the TMR0/WDT prescaler, the external RB0/INT
interrupt, TMR0, and the weak pull-ups on PORTB.
Note: To achieve a 1:1 prescaler assignment for
TMR0, assign the prescaler to the WDT
(PSA = 1). See Section 6.3.1
REGISTER 4-2: OPTION REGISTER (ADDRESS 81H)
R/W-1
RBPU
bit7
R/W-1
R/W-1
INTEDG T0CS
R/W-1
T0SE
R/W-1
PSA
R/W-1
PS2
R/W-1
PS1
R/W-1
PS0
bit0
bit 7:
RBPU: PORTB Pull-up Enable bit
1 = PORTB pull-ups are disabled
0 = PORTB pull-ups are enabled by individual port latch values
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 (CLKOUT)
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
R = Readable bit
W = Writable bit
-n = Value at POR reset
bit 2-0: PS2:PS0: Prescaler Rate Select bits
Bit Value
000
001
010
011
100
101
110
111
DS40300B-page 20
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
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
4.2.2.3
INTCON REGISTER
The INTCON register is a readable and writable
register which contains the various enable and flag bits
for all interrupt sources except the comparator module.
See Section 4.2.2.4 and Section 4.2.2.5 for a
description of the comparator enable and flag bits.
Note:
Interrupt flag bits get set when an interrupt
condition occurs regardless of the state of
its corresponding enable bit or the global
enable bit, GIE (INTCON<7>).
REGISTER 4-3: INTCON REGISTER (ADDRESS 0BH OR 8BH)
R/W-0
GIE
bit7
R/W-0
PEIE
R/W-0
T0IE
R/W-0
INTE
R/W-0
RBIE
R/W-0
T0IF
R/W-0
INTF
R/W-x
RBIF
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit, read
as ’0’
-n = Value at POR reset
-x = Unknown at POR reset
bit 7:
GIE: Global Interrupt Enable bit
1 = Enables all un-masked interrupts
0 = Disables all interrupts
bit 6:
PEIE: Peripheral Interrupt Enable bit
1 = Enables all un-masked 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 = 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 = When at least one of the RB7:RB4 pins changed state (must be cleared in software)
0 = None of the RB7:RB4 pins have changed state
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 21
PIC16F62X
4.2.2.4
PIE1 REGISTER
This register contains interrupt enable bits.
REGISTER 4-4: PIE1 REGISTER (ADDRESS 8CH)
R/W-0
EEIE
bit7
R/W-0
CMIE
R/W-0
RCIE
R/W-0
TXIE
U
-
R/W-0
CCP1IE
bit 7:
EEIE: EE Write Complete Interrupt Enable Bit
1 = Enables the EE write complete interrupt
0 = Disables the EE write complete interrupt
bit 6:
CMIE: Comparator Interrupt Enable bit
1 = Enables the comparator interrupt
0 = Disables the comparator interrupt
bit 5:
RCIE: USART Receive Interrupt Enable bit
1 = Enables the USART receive interrupt
0 = Disables the USART receive interrupt
bit 4:
TXIE: USART Transmit Interrupt Enable bit
1 = Enables the USART transmit interrupt
0 = Disables the USART transmit interrupt
bit 3:
Unimplemented: Read as ‘0’
bit 2:
CCP1IE: CCP1 Interrupt Enable bit
1 = Enables the CCP1 interrupt
0 = Disables the CCP1 interrupt
bit 1:
TMR2IE: TMR2 to PR2 Match Interrupt Enable bit
1 = Enables the TMR2 to PR2 match interrupt
0 = Disables the TMR2 to PR2 match interrupt
bit 0:
TMR1IE: TMR1 Overflow Interrupt Enable bit
1 = Enables the TMR1 overflow interrupt
0 = Disables the TMR1 overflow interrupt
DS40300B-page 22
R/W-0
R/W-0
TMR2IE TMR1IE
bit0
Preliminary
R = Readable bit
W = Writable bit
U = Unimplemented bit, read
as ’0’
-n = Value at POR reset
 1999 Microchip Technology Inc.
PIC16F62X
4.2.2.5
PIR1 REGISTER
Note:
This register contains interrupt flag bits.
Interrupt flag bits get 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.
REGISTER 4-5: PIR1 REGISTER (ADDRESS 0CH)
R/W-0
EEIF
bit7
R/W-0
CMIF
R-0
RCIF
R-0
TXIF
U
R/W-0
CCP1IF
-
R/W-0
R/W-0
TMR2IF TMR1IF
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit, read
as ’0’
-n = Value at POR reset
bit 7:
EEIF: EEPROM Write Operation Interrupt Flag bit
1 = The write operation completed (must be cleared in software)
0 = The write operation has not completed or has not been started
bit 6:
CMIF: Comparator Interrupt Flag bit
1 = Comparator input has changed
0 = Comparator input has not changed
bit 5:
RCIF: USART Receive Interrupt Flag bit
1 = The USART receive buffer is full
0 = The USART receive buffer is empty
bit 4:
TXIF: USART Transmit Interrupt Flag bit
1 = The USART transmit buffer is empty
0 = The USART transmit buffer is full
bit 3:
Unimplemented: Read as ‘0’
bit 2:
CCP1IF: CCP1 Interrupt Flag bit
Capture Mode
1 = A TMR1 register capture occurred (must be cleared in software)
0 = No TMR1 register capture occurred
Compare Mode
1 = A TMR1 register compare match occurred (must be cleared in software)
0 = No TMR1 register compare match occurred
PWM Mode
Unused in this mode
bit 1:
TMR2IF: TMR2 to PR2 Match Interrupt Flag bit
1 = TMR2 to PR2 match occurred (must be cleared in software)
0 = No TMR2 to PR2 match occurred
bit 0:
TMR1IF: TMR1 Overflow Interrupt Flag bit
1 = TMR1 register overflowed (must be cleared in software)
0 = TMR1 register did not overflow
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 23
PIC16F62X
4.2.2.6
PCON REGISTER
The PCON register contains flag bits to differentiate
between a Power-on Reset, an external MCLR reset,
WDT reset or a Brown-out Detect.
Note: BOD is unknown on Power-on Reset. It
must then be set by the user and checked
on subsequent resets to see if BOD is
cleared, indicating a brown-out has
occurred. The BOD status bit is a "don’t
care" and is not necessarily predictable if
the brown-out circuit is disabled (by
programming
BOREN
bit
in
the
Configuration word).
REGISTER 4-6: PCON REGISTER (ADDRESS 8Eh)
U-0
—
bit7
U-0
—
U-0
—
U-0
—
R/W-1
OSCF
U-0
—
R/W-q
POR
R/W-q
BOD
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit, read
as ’0’
-n = Value at POR reset
bit 7-4,2: Unimplemented: Read as '0'
bit 3:
OSCF: INTRC/ER oscillator speed
1 = 4 MHz typical(1)
0 = 37 KHz typical
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:
BOD: Brown-out Detect 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)
Note 1: When in ER oscillator mode, setting OSCF = 1 will cause the oscillator speed to change to the speed
specified by the external resistor.
DS40300B-page 24
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
4.3
4.3.2
PCL and PCLATH
The program counter (PC) is 13-bits wide. The low byte
comes from the PCL register, which is a readable and
writable register. The high byte (PC<12:8>) is not directly
readable or writable and comes from PCLATH. On any
reset, the PC is cleared. Figure 4-7 shows the two
situations for the loading of the PC. The upper example in
the figure shows how the PC is loaded on a write to PCL
(PCLATH<4:0> → PCH). The lower example in the figure
shows how the PC is loaded during a CALL or GOTO
instruction (PCLATH<4:3> → PCH).
FIGURE 4-7:
LOADING OF PC IN
DIFFERENT SITUATIONS
PCH
The PIC16F62X family has an 8 level deep x 13-bit
wide hardware stack (Figure 4-1 and Figure 4-2). 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 affected by a
PUSH or POP operation.
The stack operates as a circular buffer. This means that
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).
PCL
12
8
7
0
PC
5
8
PCLATH<4:0>
Note 1:
There are no STATUS bits to
indicate stack overflow or stack
underflow conditions.
Note 2:
There are no instructions/mnemonics
called PUSH or POP. These are actions
that occur from the execution of the
CALL, RETURN, RETLW and RETFIE
instructions, or the vectoring to an
interrupt address.
Instruction with
PCL as
Destination
ALU result
PCLATH
PCH
12
11 10
STACK
PCL
8
0
7
PC
GOTO, CALL
2
PCLATH<4:3>
11
Opcode <10:0>
PCLATH
4.3.1
COMPUTED GOTO
A computed GOTO is accomplished by adding an offset
to the program counter (ADDWF PCL). When doing a
table read using a computed GOTO method, care
should be exercised if the table location crosses a PCL
memory boundary (each 256 byte block). Refer to the
application note “Implementing a Table Read" (AN556).
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 25
PIC16F62X
4.4
Indirect Addressing, INDF and FSR
Registers
EXAMPLE 4-1:
The INDF register is not a physical register. Addressing
the INDF register will cause indirect addressing.
NEXT
Indirect addressing is possible by using the INDF register.
Any instruction using the INDF register actually accesses
data pointed to by the file select register (FSR). Reading
INDF itself indirectly will produce 00h. Writing to the INDF
register indirectly results in a no-operation (although status bits may be affected). An effective 9-bit address is
obtained by concatenating the 8-bit FSR register and the
IRP bit (STATUS<7>), as shown in Figure 4-8.
INDIRECT ADDRESSING
movlw
0x20
movwf
FSR
;initialize pointer
;to RAM
clrf
INDF
;clear INDF register
incf
FSR
;inc pointer
btfss
FSR,4
;all done?
goto
NEXT
;no clear next
;yes continue
CONTINUE:
A simple program to clear RAM location 20h-2Fh using
indirect addressing is shown in Example 4-1.
FIGURE 4-8:
DIRECT/INDIRECT ADDRESSING PIC16F62X
Direct Addressing
RP1
RP0
bank select
6
from opcode
Indirect Addressing
0
IRP
7
bank select
location select
00
01
10
FSR register
0
location select
11
00h
180h
Data
Memory
7Fh
1FFh
Bank 0
Bank 1
Bank 2
Bank 3
For memory map detail see Figure 4-3.
DS40300B-page 26
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
5.0
I/O PORTS
The PIC16F62X have two ports, PORTA and PORTB.
Some pins for these 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.
5.1
PORTA and TRISA Registers
PORTA is an 8-bit wide latch. RA4 is a Schmitt Trigger
input and an open drain output. Port RA4 is multiplexed
with the T0CKI clock input. RA5 is a Schmitt Trigger input
only and has no output drivers. All other RA port pins have
Schmitt Trigger input levels and full CMOS output drivers.
All pins have data direction bits (TRIS registers) which can
configure these pins as input or output.
A ’1’ in the TRISA register puts the corresponding output
driver in a hi- impedance mode. A ’0’ in the TRISA register
puts the contents of the output latch on the selected pin(s).
Reading the PORTA register reads the status of the pins
whereas writing to it will write to the port latch. All write
operations are read-modify-write operations. So a write
to a port implies that the port pins are first read, then this
value is modified and written to the port data latch.
The PORTA pins are multiplexed with comparator and
voltage reference functions. The operation of these
pins are selected by control bits in the CMCON
(comparator control register) register and the VRCON
(voltage reference control register) register. When
selected as a comparator input, these pins will read
as ’0’s.
 1999 Microchip Technology Inc.
Note 1: On reset, the TRISA register is set to all
inputs. The digital inputs are disabled and
the comparator inputs are forced to
ground to reduce excess current consumption.
Note 2: When RA6/OSC2/CLKOUT is configured
as CLKOUT, the corresponding TRIS bit is
overridden and the pin is configured as an
output. The PORTA data bit reads 0, and
the PORTA TRIS bit reads 0.
TRISA controls the direction of the RA pins, even when
they are being used as comparator inputs. The user
must make sure to keep the pins configured as inputs
when using them as comparator inputs.
The RA2 pin will also function as the output for the
voltage reference. When in this mode, the VREF pin is a
very high impedance output. The user must configure
TRISA<2> bit as an input and use high impedance
loads.
In one of the comparator modes defined by the
CMCON register, pins RA3 and RA4 become outputs
of the comparators. The TRISA<4:3> bits must be
cleared to enable outputs to use this function.
EXAMPLE 5-1:
CLRF
PORTA
MOVLW 0X07
MOVWF CMCON
INITIALIZING PORTA
;Initialize PORTA by setting
;output data latches
;Turn comparators off and
;enable pins for I/O
;functions
BCF
STATUS, RP1
BSF
STATUS, RP0 ;Select Bank1
MOVLW 0x1F
;Value used to initialize
;data direction
MOVWF TRISA
;Set RA<4:0> as inputs
;TRISA<7:5> are always
;read as ’0’.
Preliminary
DS40300B-page 27
PIC16F62X
FIGURE 5-1:
Data
Bus
BLOCK DIAGRAM OF
RA0/AN0:RA1/AN1 PINS
D
FIGURE 5-2:
Data
Bus
Q
VDD
VDD
WR
PORTA
CK
Q
Q
VDD
VDD
WR
PORTA
CK
P
Q
P
Data Latch
Data Latch
D
D
BLOCK DIAGRAM OF
RA2/VREF PIN
D
Q
Q
I/O Pin
WR
TRISA
N
CK
Q
WR
TRISA
VSS
CK
Q
VSS
Analog
Input Mode
Analog
Input Mode
RD TRISA
Schmitt Trigger
Input Buffer
Q
RA2 Pin
VSS
TRIS Latch
VSS
TRIS Latch
N
RD TRISA
Schmitt Trigger
Input Buffer
Q
D
D
EN
EN
RD PORTA
RD PORTA
To Comparator
To Comparator
VROE
VREF
DS40300B-page 28
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 5-3:
Data
Bus
BLOCK DIAGRAM OF THE RA3/AN3 PIN
Comparator Mode = 110
D
VDD
Q
Comparator Output
WR
PORTA
VDD
1
CK
Q
D
P
0
Data Latch
Q
RA3 Pin
N
WR
TRISA
CK
Q
VSS
VSS
TRIS Latch
Analog
Input Mode
Schmitt Trigger
Input Buffer
RD TRISA
Q
D
EN
RD PORTA
To Comparator
FIGURE 5-4:
Data
Bus
BLOCK DIAGRAM OF RA4/T0CKI PIN
Comparator Mode = 110
D
Q
Comparator Output
WR
PORTA
1
CK
Q
Data Latch
D
WR
TRISA
0
Q
RA4 Pin
N
CK
Q
VSS
TRIS Latch
VSS
Schmitt Trigger
Input Buffer
RD TRISA
Q
D
EN
RD PORTA
TMR0 Clock Input
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 29
PIC16F62X
FIGURE 5-5:
BLOCK DIAGRAM OF THE RA5/MCLR/THV PIN
MCLRE
MCLR circuit
VDD
MCLR Filter(1)
Program mode
HV Detect
RA5/MCLR/THV
Data
Bus
D
WR
PORT
CK
Q
VDD
Q
P
VSS
Data Latch
D
WR
TRIS
Q
N
CK
Q
TRIS Latch
VSS
RD TRIS
Q
D
EN
RD Port
DS40300B-page 30
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 5-6:
BLOCK DIAGRAM OF RA6/OSC2/CLKOUT PIN
(Fosc=101,111)
From OSC1
CLKOUT (FOSC/4)
1
VDD
0
Data
Bus
D
WR
PORTA
CK
Q
VDD
Q
P
RA6/OSC2/CLKOUT Pin
VSS
Data Latch
D
WR
TRISA
Oscillator
Circuit
Q
N
CK
Q
TRIS Latch
VSS
(Fosc=100, 101, 110, 111)
RD TRISA
(Fosc=110, 100)
Q
Schmitt Trigger
Input Buffer
D
EN
RD PORTA
CLKOUT is 1/4 of the Fosc frequency.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 31
PIC16F62X
FIGURE 5-7:
BLOCK DIAGRAM OF RA7/OSC1/CLKIN PIN
To OSC2
Oscillator
Circuit
VDD
CLKIN to core
Data
Bus
D
Q
VDD
Q
P
RA7/OSC1/CLKIN Pin
WR
PORTA
CK
Data Latch
D
WR
TRISA
Schmitt Trigger
VSS
Q
N
CK
Q
TRIS Latch
(Fosc=101, 100)
VSS
(Fosc=101, 100)
Schmitt Trigger
Input Buffer
RD TRISA
Q
D
EN
RD PORTA
DS40300B-page 32
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
TABLE 5-1:
PORTA FUNCTIONS
Bit #
Buffer
Type
RA0/AN0
RA1/AN1
RA2/AN2/VREF
RA3/AN3
RA4/T0CKI
bit0
bit1
bit2
bit3
bit4
ST
ST
ST
ST
ST
RA5/MCLR/THV
bit5
ST
RA6/OSC2/CLKOUT
bit6
ST
Name
RA7/OSC1/CLKIN
bit7
ST
Legend: ST = Schmitt Trigger input
TABLE 5-2:
Address Name
Function
Bi-directional I/O port/comparator input
Bi-directional I/O port/comparator input
Bi-directional I/O port/analog/comparator input or VREF output
Bi-directional I/O port/analog/comparator input/comparator output
Bi-directional I/O port/external clock input for TMR0 or comparator output.
Output is open drain type.
Input port/master clear (reset input/programming voltage input. When
configured as MCLR, this pin is an active low reset to the device. Voltage
on MCLR/THV must not exceed VDD during normal device operation.
Bi-directional I/O port/Oscillator crystal output. Connects to crystal or resonator in crystal oscillator mode. In ER mode, OSC2 pin outputs CLKOUT
which has 1/4 the frequency of OSC1, and denotes the instruction cycle
rate.
Bi-directional I/O port/oscillator crystal input/external clock source input.
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Value on
All Other
Resets
05h
PORTA
RA7
RA6
RA5
RA4
RA3
RA2
RA1
RA0
xxxx 0000
xxxu 0000
85h
TRISA
TRISA7
TRISA6
—
TRISA4
TRISA3
TRISA2
TRISA1
TRISA0
11-1 1111
11-1 1111
1Fh
CMCON
C2OUT
C1OUT
C2INV
C1INV
CIS
CM2
CM1
CM0
0000 0000
0000 0000
9Fh
VRCON
VREN
VROE
VRR
—
VR3
VR2
VR1
VR0
000- 0000
000- 0000
Legend: — = Unimplemented locations, read as ‘0’, u = unchanged, x = unknown
Note:
Shaded bits are not used by PORTA.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 33
PIC16F62X
5.2
PORTB and TRISB Registers
PORTB is an 8-bit wide bi-directional port. The
corresponding data direction register is TRISB. A ’1’ in
the TRISB register puts the corresponding output driver
in a high impedance mode. A ’0’ in the TRISB register
puts the contents of the output latch on the selected
pin(s).
PORTB is multiplexed with the interrupt, USART, CCP
module and the TMR1 clock input/output. The standard
port functions and the alternate port functions are
shown in Table 5-3.
Reading PORTB register reads the status of the pins,
whereas writing to it will write to the port latch. All write
operations are read-modify-write operations. So a write
to a port implies that the port pins are first read, then
this value is modified and written to the port data latch.
Each of the PORTB pins has a weak internal pull-up
(≈200 µA typical). A single control bit can turn on all the
pull-ups. This is done by clearing the RBPU
(OPTION<7>) bit. The weak pull-up is automatically
turned off when the port pin is configured as an output.
The pull-ups are disabled on Power-on Reset.
Four of PORTB’s pins, RB7:RB4, have an interrupt on
change feature. Only pins configured as inputs can
cause this interrupt to occur (i.e., any RB7:RB4 pin
configured as an output is excluded from the interrupt
on change comparison). The input pins (of RB7:RB4)
are compared with the old value latched on the last
read of PORTB. The “mismatch” outputs of RB7:RB4
are OR’ed together to generate the RBIF interrupt (flag
latched in INTCON<0>).
DS40300B-page 34
This interrupt can wake the device from SLEEP. The
user, in the interrupt service routine, can clear the
interrupt in the following manner:
a)
Any read or write of PORTB. This will end the
mismatch condition.
Clear flag bit RBIF.
b)
A mismatch condition will continue to set flag bit RBIF.
Reading PORTB will end the mismatch condition, and
allow flag bit RBIF to be cleared.
This interrupt on mismatch feature, together with
software configurable pull-ups on these four pins allow
easy interface to a key pad and make it possible for
wake-up on key-depression. (See AN552 in the
Microchip Embedded Control Handbook.)
Note:
If a change on the I/O pin should occur
when the read operation is being executed
(start of the Q2 cycle), then the RBIF interrupt flag may not get set.
The interrupt on change feature is recommended for
wake-up on key depression operation and operations
where PORTB is only used for the interrupt on change
feature. Polling of PORTB is not recommended while
using the interrupt on change feature.
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 5-8:
BLOCK DIAGRAM OF RB0/INT PIN
VDD
VDD
RBPU
weak
P pull-up
RB0/INT pin
Data Bus
WR PORTB
D
Q
VSS
CK
Data Latch
D
WR TRISB
Q
TTL
input
buffer
CK
TRIS Latch
Schmitt Trigger
Buffer
RD TRISB
Q
D
EN
EN
RD PORTB
INT input
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 35
PIC16F62X
FIGURE 5-9:
BLOCK DIAGRAM OF RB1/TX/DT PIN
VDD
RBPU
P weak pull-up
PORT/PERIPHERAL Select
(1)
USART data output
0
VDD
1
Data Bus
WR PORTB
D
Q
CK
Q
P
VDD
Data Latch
WR TRISB
D
Q
CK
Q
RB1/RX/DT
pin
N
VSS
TRIS Latch
VSS
RD TRISB
TTL
input
buffer
Peripheral OE(2)
Q
D
RD PORTB
EN
USART receive input
Schmitt
Trigger
RD PORTB
Note 1: Port/Peripheral select signal selects between port data and peripheral output.
Note 2: Peripheral OE( output enable) is only active if peripheral select is active.
DS40300B-page 36
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 5-10: BLOCK DIAGRAM OF RB2/TX/CK PIN
VDD
RBPU
P weak pull-up
VDD
PORT/PERIPHERAL Select(1)
USART TX/CK output
0
VDD
1
Data Bus
WR PORTB
D
Q
CK
Q
RB2/TX/CK
pin
P
VSS
Data Latch
WR TRISB
D
Q
CK
Q
N
TRIS Latch
Vss
RD TRISB
TTL
input
buffer
Peripheral OE(2)
Q
D
RD PORTB
EN
EN
USART Slave Clock in
Schmitt
Trigger
RD PORTB
Note 1: Port/Peripheral select signal selects between port data and peripheral output.
Note 2: Peripheral OE( output enable) is only active if peripheral select is active.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 37
PIC16F62X
FIGURE 5-11: BLOCK DIAGRAM OF THE RB3/CCP1 PIN
VDD
RBPU
P weak pull-up
Port/Peripheral Select(1)
PWM/Compare output
0
VDD
1
Data Bus
WR PORTB
D
Q
CK
Q
P
VDD
Data Latch
D
WR TRISB
CK
RB3/CCP1
pin
Q
N
Q
VSS
TRIS Latch
Vss
RD TRISB
TTL
input
buffer
Q
D
RD PORTB
EN
EN
CCP input
Schmitt
Trigger
RD PORTB
Note 1: Peripheral Select is defined by CCP1M3:CCP1M0. (CCP1CON<3:0>)
DS40300B-page 38
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 5-12: BLOCK DIAGRAM OF RB4/PGM PIN
VDD
RBPU
P weak pull-up
VDD
Data Bus
WR PORTB
D
Q
CK
Q
P
VDD
Data Latch
WR TRISB
D
Q
CK
Q
RB4/PGM
N
VSS
TRIS Latch
VSS
RD TRISB
LVP
RD PORTB
PGM input
TTL
input
buffer
Schmitt
Trigger
Q
D
Q1
EN
Set RBIF
From other
RB<7:4> pins
Q
D
RD Port
EN
Note:
Q3
The low voltage programming disables the interrupt on change and the weak pullups on RB4.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 39
PIC16F62X
FIGURE 5-13: BLOCK DIAGRAM OF RB5 PIN
VDD
RBPU
Data Bus
D
weak VDD
P pull-up
Q
RB5 pin
WR PORTB
CK
Data Latch
VSS
D
WR TRISB
Q
CK
TRIS Latch
TTL
input
buffer
RD TRISB
Q
D
RD PORTB
EN
Q1
Set RBIF
From other
RB<7:4> pins
Q
D
EN
DS40300B-page 40
Preliminary
RD Port
Q3
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 5-14:
BLOCK DIAGRAM OF RB6/T1OSO/T1CKI PIN
VDD
RBPU
P weak pull-up
VDD
Data Bus
WR PORTB
D
Q
CK
Q
P
VDD
Data Latch
WR TRISB
D
Q
CK
Q
RB6/
T1OSO/
T1CKI
pin
N
VSS
TRIS Latch
VSS
RD TRISB
T1OSCEN
TTL
input
buffer
RD PORTB
TMR1 Clock
From RB7
Schmitt
Trigger
TMR1 oscillator
Serial programming clock
Q
D
EN
Q1
Set RBIF
From other
RB<7:4> pins
Q
D
RD Port
EN
 1999 Microchip Technology Inc.
Preliminary
Q3
DS40300B-page 41
PIC16F62X
FIGURE 5-15: BLOCK DIAGRAM OF THE RB7/T1OSI PIN
VDD
RBPU
TMR1 oscillator
P weak pull-up
To RB6
T1OSCEN
VDD
VDD
Data Bus
WR PORTB
D
Q
CK
Q
P
RB7/T1OSI
pin
Data Latch
WR TRISB
D
Q
CK
Q
VSS
N
TRIS Latch
Vss
RD TRISB
T10SCEN
TTL
input
buffer
RD PORTB
Serial programming input
Schmitt
Trigger
Q
D
EN
Q1
Set RBIF
From other
RB<7:4> pins
Q
D
RD Port
EN
DS40300B-page 42
Preliminary
Q3
 1999 Microchip Technology Inc.
PIC16F62X
TABLE 5-3:
PORTB FUNCTIONS
Name
Bit #
Buffer
Type
bit0
TTL/ST(1)
Function
Bi-directional I/O port/external interrupt. Can be software programmed for
internal weak pull-up.
RB1/RX/DT
bit1
TTL/ST(3) Bi-directional I/O port/ USART receive pin/synchronous data I/O. Can be
software programmed for internal weak pull-up.
RB2/TX/CK
bit2
TTL/ST(3) Bi-directional I/O port/ USART transmit pin/synchronous clock I/O. Can be
software programmed for internal weak pull-up.
RB3/CCP1
bit3
TTL/ST(4) Bi-directional I/O port/Capture/Compare/PWM I/O. Can be software programmed for internal weak pull-up.
RB4/PGM
bit4
TTL/ST(5) Bi-directional I/O port/Low voltage programming input pin. Wake-up from
SLEEP on pin change. Can be software programmed for internal weak
pull-up. When low voltage programming is enabled, the interrupt on pin
change and weak pull-up resistor are disabled.
RB5
bit5
TTL
Bi-directional I/O port/Wake-up from SLEEP on pin change. Can be software programmed for internal weak pull-up.
RB6/T1OSO/T1CKI
bit6
TTL/ST(2) Bi-directional I/O port/Timer1 oscillator output/Timer1 clock input. Wake up
from SLEEP on pin change. Can be software programmed for internal weak
pull-up.
(2)
RB7/T1OSI
bit7
Bi-directional I/O port/Timer1 oscillator input. Wake up from SLEEP on pin
TTL/ST
change. Can be software programmed for internal weak pull-up.
Legend: ST = Schmitt Trigger, TTL = TTL input
Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt.
Note 2: This buffer is a Schmitt Trigger input when used in serial programming mode.
Note 3: This buffer is a Schmitt Trigger I/O when used in USART/synchronous mode.
Note 4: This buffer is a Schmitt Trigger I/O when used in CCP mode.
Note 5: This buffer is a Schmitt Trigger input when used in low voltage program mode.
RB0/INT
TABLE 5-4:
SUMMARY OF REGISTERS ASSOCIATED WITH PORT
Address Name
Bit 7
Bit 6
06h
PORTB
RB7
RB6
86h
TRISB
TRISB7
TRISB6
81h
OPTION
RBPU
INTEDG
Legend:
Note:
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Value on
All Other
Resets
RB5
RB4
RB3
RB2
RB1
RB0
xxxx xxxx
uuuu uuuu
TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 1111 1111
1111 1111
T0CS
T0SE
PSA
PS2
PS1
PS0
1111 1111
1111 1111
u = unchanged, x = unknown
Shaded bits are not used by PORTB.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 43
PIC16F62X
5.3
I/O Programming Considerations
5.3.1
BI-DIRECTIONAL I/O PORTS
EXAMPLE 5-2:
READ-MODIFY-WRITE
INSTRUCTIONS ON AN
I/O PORT
Any instruction which writes, operates internally as a
read followed by a write operation. The BCF and BSF
instructions, for example, read the register into the
CPU, execute the bit operation and write the result back
to the register. Caution must be used when these
instructions are applied to a port with both inputs and
outputs defined. For example, a BSF operation on bit5
of PORTB will cause all eight bits of PORTB to be read
into the CPU. Then the BSF operation takes place on
bit5 and PORTB is written to the output latches. If
another bit of PORTB is used as a bidirectional I/O pin
(e.g., bit0) and it is defined as an input at this time, the
input signal present on the pin itself would be read into
the CPU and re-written to the data latch of this
particular pin, overwriting the previous content. As long
as the pin stays in the input mode, no problem occurs.
However, if bit0 is switched into output mode later on,
the content of the data latch may now be unknown.
; Initial PORT settings: PORTB<7:4> Inputs
;
;
PORTB<3:0> Outputs
; PORTB<7:6> have external pull-up and are not
; connected to other circuitry
;
;
PORT latch PORT pins
;
---------- ---------BDF STATUS,RPO
;
BCF PORTB, 7
; 01pp pppp 11pp pppp
BCF PORTB, 6
; 10pp pppp 11pp pppp
BSF STATUS,RP0
;
BCF TRISB, 7
; 10pp pppp 11pp pppp
BCF TRISB, 6
; 10pp pppp 10pp pppp
;
; Note that the user may have expected the pin
; values to be 00pp pppp. The 2nd BCF caused
; RB7 to be latched as the pin value (High).
Reading a port register, reads the values of the port
pins. Writing to the port register writes the value to the
port latch. When using read modify write instructions
(ex. BCF, BSF, etc.) on a port, the value of the port pins
is read, the desired operation is done to this value, and
this value is then written to the port latch.
The actual write to an I/O port happens at the end of an
instruction cycle, whereas for reading, the data must be
valid at the beginning of the instruction cycle
(Figure 5-16). Therefore, care must be exercised if a
write followed by a read operation is carried out on the
same I/O port. The sequence of instructions should be
such to allow the pin voltage to stabilize (load
dependent) before the next instruction which causes
that file to be read into the CPU is executed. Otherwise,
the previous state of that pin may be read into the CPU
rather than the new state. When in doubt, it is better to
separate these instructions with a NOP or another
instruction not accessing this I/O port.
5.3.2
Example 5-2 shows the effect of two sequential
read-modify-write instructions (ex., BCF, BSF, etc.) on
an I/O port.
A pin actively outputting a Low or High should not be
driven from external devices at the same time in order
to change the level on this pin (“wired-or”, “wired-and”).
The resulting high output currents may damage
the chip.
SUCCESSIVE OPERATIONS ON I/O PORTS
FIGURE 5-16: SUCCESSIVE I/O OPERATION
Q1
PC
PC
Instruction
Instruction
fetched
fetched
Q2
Q3
Q3
Q4
PC
PC
MOWF PORTB
MOVWF PORTB
Write to PORTB
Write to
PORTB
Q1
Q1
Q2
Q2
Q3 Q4
Q4
Q3
PC
PC +
+1
1
MOVF PORTB, W
MOVF PORTB, W
Read to PORTB
Read PORTB
Q1
Q2
Q3
Q4
Q1
Q1
PC +
+2
PC
2
NOP
NOP
Q2
Q3
PC
PC ++ 33
NOP
NOP
Port
pin
Port pin
sampled
here
sampled here
DS40300B-page 44
Note:
This example shows write to PORTB
followed by a read from PORTB.
Note that:
data setup time = (0.25 TCY - TPD)
where TCY = instruction cycle and
TPD = propagation delay of Q1 cycle
to output valid.
RB<7:0>
RB <7:0>
TPD
PD
Execute
Execute
MOVWF
MOVWF
PORTB
PORTB
Q4
Execute
Execute
MOVWF
MOVF
PORTBW
PORTB,
Preliminary
Therefore, at higher clock frequencies,
a write followed by a read may be
problematic.
Execute
Execute
NOP
NOP
 1999 Microchip Technology Inc.
PIC16F62X
6.0
TIMER0 MODULE
bit (OPTION<4>). Clearing the T0SE bit selects the
rising edge. Restrictions on the external clock input are
discussed in detail in Section 6.2.
The Timer0 module timer/counter has the following
features:
•
•
•
•
•
•
The prescaler is shared between the Timer0 module
and the Watchdog Timer. The prescaler assignment is
controlled in software by the control bit PSA
(OPTION<3>). Clearing the PSA bit will assign the
prescaler to Timer0. The prescaler is not readable or
writable. When the prescaler is assigned to the Timer0
module, prescale value of 1:2, 1:4, ..., 1:256 are
selectable. Section 6.3 details the operation of the
prescaler.
8-bit timer/counter
Readable and writable
8-bit software programmable prescaler
Internal or external clock select
Interrupt on overflow from FFh to 00h
Edge select for external clock
Figure 6-1 is a simplified block diagram of the Timer0
module.
6.1
Timer mode is selected by clearing the T0CS bit
(OPTION<5>). In timer mode, the TMR0 will increment
every instruction cycle (without prescaler). If Timer0 is
written, the increment is inhibited for the following two
cycles (Figure 6-2 and Figure 6-3). The user can work
around this by writing an adjusted value to TMR0.
Timer0 interrupt is generated when the TMR0 register
timer/counter overflows from FFh to 00h. This overflow
sets the T0IF bit. The interrupt can be masked by
clearing the T0IE bit (INTCON<5>). The T0IF bit
(INTCON<2>) must be cleared in software by the
Timer0 module interrupt service routine before
re-enabling this interrupt. The Timer0 interrupt cannot
wake the processor from SLEEP since the timer is shut
off during SLEEP. See Figure 6-4 for Timer0 interrupt
timing.
Counter mode is selected by setting the T0CS bit. In
this mode Timer0 will increment either on every rising
or falling edge of pin RA4/T0CKI. The incrementing
edge is determined by the source edge (T0SE) control
FIGURE 6-1:
TIMER0 Interrupt
TIMER0 BLOCK DIAGRAM
Data bus
RA4/T0CKI
pin
FOSC/4
0
PSout
1
1
Programmable
Prescaler
0
TMR0
PSout
(2 TCY delay)
T0SE
PS2:PS0
8
Sync with
Internal
clocks
Set Flag bit T0IF
on Overflow
PSA
T0CS
Note 1:
2:
Bits T0SE, T0CS, PS2, PS1, PS0 and PSA are located in the OPTION register.
The prescaler is shared with Watchdog Timer (Figure 6-6)
FIGURE 6-2:
PC
(Program
Counter)
TIMER0 (TMR0) TIMING: INTERNAL CLOCK/NO PRESCALER
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
PC-1
Instruction
Fetch
TMR0
PC
MOVWF TMR0
T0
T0+1
Instruction
Executed
 1999 Microchip Technology Inc.
PC+1
PC+2
PC+3
MOVF TMR0,W MOVF TMR0,W MOVF TMR0,W
MOVF TMR0,W
NT0
T0+2
Write TMR0
executed
PC+4
Read TMR0
reads NT0
Read TMR0
reads NT0
Preliminary
PC+5
MOVF TMR0,W
NT0+1
Read TMR0
reads NT0
PC+6
Read TMR0
reads NT0 + 1
NT0+2
T0
Read TMR0
reads NT0 + 2
DS40300B-page 45
PIC16F62X
FIGURE 6-3:
PC
(Program
Counter)
TIMER0 TIMING: INTERNAL CLOCK/PRESCALE 1:2
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
PC-1
PC
PC+1
MOVWF TMR0
Instruction
Fetch
T0
TMR0
PC+2
PC+3
T0+1
Instruction
Execute
PC+5
MOVF TMR0,W
PC+6
MOVF TMR0,W
NT0+1
NT0
Read TMR0
reads NT0
Write TMR0
executed
FIGURE 6-4:
PC+4
MOVF TMR0,W MOVF TMR0,W MOVF TMR0,W
Read TMR0
reads NT0
Read TMR0
reads NT0
Read TMR0
reads NT0
Read TMR0
reads NT0 + 1
TIMER0 INTERRUPT TIMING
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
OSC1
CLKOUT(3)
TMR0 timer
FFh
FEh
1
T0IF bit
(INTCON<2>)
00h
01h
02h
1
GIE bit
(INTCON<7>)
Interrupt Latency Time
INSTRUCTION FLOW
PC
PC
Instruction
fetched
Inst (PC)
Instruction
executed
Inst (PC-1)
PC +1
PC +1
Inst (PC+1)
Inst (PC)
Dummy cycle
0004h
0005h
Inst (0004h)
Inst (0005h)
Dummy cycle
Inst (0004h)
Note 1: T0IF interrupt flag is sampled here (every Q1).
2: Interrupt latency = 3TCY, where TCY = instruction cycle time.
3: CLKOUT is available only in ER and INTRC (with clockout) oscillator modes.
DS40300B-page 46
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
6.2
Using Timer0 with External Clock
When an external clock input is used for Timer0, it must
meet certain requirements. The external clock
requirement is due to internal phase clock (TOSC)
synchronization. Also, there is a delay in the actual
incrementing of Timer0 after synchronization.
6.2.1
EXTERNAL CLOCK SYNCHRONIZATION
When no prescaler is used, the external clock input is
the same as the prescaler output. The synchronization
of T0CKI with the internal phase clocks is
accomplished by sampling the prescaler output on the
Q2 and Q4 cycles of the internal phase clocks
(Figure 6-5). Therefore, it is necessary for T0CKI to be
high for at least 2TOSC (and a small RC delay of 20 ns)
and low for at least 2TOSC (and a small RC delay of
20 ns). Refer to the electrical specification of the
desired device.
FIGURE 6-5:
When a prescaler is used, the external clock input is
divided by the asynchronous ripple-counter type
prescaler so that the prescaler output is symmetrical.
For the external clock to meet the sampling
requirement, the ripple-counter must be taken into
account. Therefore, it is necessary for T0CKI to have a
period of at least 4TOSC (and a small RC delay of 40 ns)
divided by the prescaler value. The only requirement on
T0CKI high and low time is that they do not violate the
minimum pulse width requirement of 10 ns. Refer to
parameters 40, 41 and 42 in the electrical specification
of the desired device.
6.2.2
TIMER0 INCREMENT DELAY
Since the prescaler output is synchronized with the
internal clocks, there is a small delay from the time the
external clock edge occurs to the time the TMR0 is
actually incremented. Figure 6-5 shows the delay from
the external clock edge to the timer incrementing.
TIMER0 TIMING WITH EXTERNAL CLOCK
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
External Clock Input or
Prescaler output (2)
Q1 Q2 Q3 Q4
Small pulse
misses sampling
(1)
(3)
External Clock/Prescaler
Output after sampling
Increment Timer0 (Q4)
Timer0
Note 1:
2:
3:
T0
T0 + 1
T0 + 2
Delay from clock input change to Timer0 increment is 3Tosc to 7Tosc. (Duration of Q = Tosc). Therefore, the error in
measuring the interval between two edges on Timer0 input = ±4Tosc max.
External clock if no prescaler selected, Prescaler output otherwise.
The arrows indicate the points in time where sampling occurs.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 47
PIC16F62X
6.3
Prescaler
The PSA and PS2:PS0 bits (OPTION<3:0>) determine
the prescaler assignment and prescale ratio.
An 8-bit counter is available as a prescaler for the
Timer0 module, or as a postscaler for the Watchdog
Timer, respectively (Figure 6-6). For simplicity, this
counter is being referred to as “prescaler” throughout
this data sheet. Note that there is only one prescaler
available which is mutually exclusive 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.
FIGURE 6-6:
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (e.g., CLRF 1,
MOVWF 1, BSF 1, x....etc.) will clear the prescaler. When assigned to WDT, a CLRWDT instruction
will clear the prescaler along with the Watchdog Timer.
The prescaler is not readable or writable.
BLOCK DIAGRAM OF THE TIMER0/WDT PRESCALER
Data Bus
CLKOUT (=Fosc/4)
0
T0CKI
pin
8
M
U
X
1
M
U
X
0
1
SYNC
2
Cycles
TMR0 reg
T0SE
T0CS
0
Watchdog
Timer
1
M
U
X
Set flag bit T0IF
on Overflow
PSA
8-bit Prescaler
8
8-to-1MUX
PS0 - PS2
PSA
WDT Enable bit
1
0
MUX
PSA
WDT
Time-out
Note: T0SE, T0CS, PSA, PS0-PS2 are bits in the OPTION register.
DS40300B-page 48
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
6.3.1
SWITCHING PRESCALER ASSIGNMENT
The prescaler assignment is fully under software
control (i.e., it can be changed “on the fly” during
program execution). To avoid an unintended device
RESET,
the
following
instruction
sequence
(Example 6-1) must be executed when changing the
prescaler assignment from Timer0 to WDT.
To change prescaler from the WDT to the TMR0
module use the sequence shown in Example 6-2. This
precaution must be taken even if the WDT is disabled.
EXAMPLE 6-2:
CHANGING PRESCALER
(WDT→TIMER0)
CLRWDT
EXAMPLE 6-1:
CHANGING PRESCALER
(TIMER0→WDT)
1.BCF
STATUS, RP0
2.CLRWDT
3.CLRF
4.BSF
5.MOVLW
6.MOVWF
TMR0
STATUS, RP0
'00101111’b
OPTION
7.CLRWDT
8.MOVLW '00101xxx’b
9.MOVWF OPTION
10.BCF
STATUS, RP0
TABLE 6-1:
Address
Name
01h
TMR0
;Skip if already in
; Bank 0
;Clear WDT
;Clear TMR0 & Prescaler
;Bank 1
;These 3 lines (5, 6, 7)
; are required only if
; desired PS<2:0> are
; 000 or 001
;Set Postscaler to
; desired WDT rate
;Return to Bank 0
;Clear WDT and
;prescaler
BSF
MOVLW
STATUS, RP0
b'xxxx0xxx'
MOVWF
BCF
OPTION_REG
STATUS, RP0
;Select TMR0, new
;prescale value and
;clock source
REGISTERS ASSOCIATED WITH TIMER0
0Bh/8Bh/
INTCON
10Bh/18Bh
81h
OPTION
85h
TRISA
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Timer0 module register
Value on
POR
Value on
All Other
Resets
xxxx xxxx uuuu uuuu
GIE
—
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x 0000 000u
RBPU
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
1111 1111 1111 1111
TRISA7
TRISA6
—
TRISA2
TRISA1
TRISA4 TRISA3
TRISA0 11-1 1111 11-1 1111
Legend: — = Unimplemented locations, read as ‘0’, u = unchanged, x = unknown
Note:
Shaded bits are not used by TMR0 module.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 49
PIC16F62X
7.0
TIMER1 MODULE
In timer mode, Timer1 increments every instruction
cycle. In counter mode, it increments on every rising
edge of the external clock input.
The Timer1 module is a 16-bit timer/counter consisting
of two 8-bit registers (TMR1H and TMR1L) which are
readable and writable. The TMR1 Register pair
(TMR1H:TMR1L) increments from 0000h to FFFFh
and rolls over to 0000h. The TMR1 Interrupt, if enabled,
is generated on overflow which is latched in interrupt
flag bit TMR1IF (PIR1<0>). This interrupt can be
enabled/disabled by setting/clearing TMR1 interrupt
enable bit TMR1IE (PIE1<0>).
Timer1 can be enabled/disabled by setting/clearing
control bit TMR1ON (T1CON<0>).
Timer1 also has an internal “reset input”. This reset can
be generated by the CCP module (Section 10.0).
Register 7-1 shows the Timer1 control register.
For the PIC16F627 and PIC16F628, when the Timer1
oscillator is enabled (T1OSCEN is set), the RB7/T1OSI
and RB6/T1OSO/T1CKI pins become inputs. That is,
the TRISB<7:6> value is ignored.
Timer1 can operate in one of two modes:
• As a timer
• As a counter
The operating mode is determined by the clock select
bit, TMR1CS (T1CON<1>).
REGISTER 7-1: T1CON: TIMER1 CONTROL REGISTER (ADDRESS 10h)
U-0
—
bit7
U-0
—
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit,
read as ‘0’
- n = Value at POR reset
bit 7-6: Unimplemented: Read as '0'
bit 5-4: T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits
11 = 1:8 Prescale value
10 = 1:4 Prescale value
01 = 1:2 Prescale value
00 = 1:1 Prescale value
bit 3:
T1OSCEN: Timer1 Oscillator Enable Control bit
1 = Oscillator is enabled
0 = Oscillator is shut off
Note: The oscillator inverter and feedback resistor are turned off to eliminate power drain
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 RB6/T1OSO/T1CKI (on the rising edge)
0 = Internal clock (FOSC/4)
bit 0:
TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1
DS40300B-page 50
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
7.1
Timer1 Operation in Timer Mode
internal phase clock (Tosc) synchronization. Also, there
is a delay in the actual incrementing of TMR1 after synchronization.
Timer mode is selected by clearing the TMR1CS
(T1CON<1>) bit. In this mode, the input clock to the
timer is FOSC/4. The synchronize control bit T1SYNC
(T1CON<2>) has no effect since the internal clock is
always in sync.
7.2
When the prescaler is 1:1, the external clock input is
the same as the prescaler output. The synchronization
of T1CKI with the internal phase clocks is accomplished by sampling the prescaler output on the Q2 and
Q4 cycles of the internal phase clocks. Therefore, it is
necessary for T1CKI to be high for at least 2Tosc (and
a small RC delay of 20 ns) and low for at least 2Tosc
(and a small RC delay of 20 ns). Refer to the appropriate electrical specifications, parameters 45, 46, and 47.
Timer1 Operation in Synchronized
Counter Mode
Counter mode is selected by setting bit TMR1CS. In
this mode the timer increments on every rising edge of
clock input on pin RB7/T1OSI when bit T1OSCEN is
set or pin RB6/T1OSO/T1CKI when bit T1OSCEN is
cleared.
When a prescaler other than 1:1 is used, the external
clock input is divided by the asynchronous ripple-counter type prescaler so that the prescaler output
is symmetrical. In order for the external clock to meet
the sampling requirement, the ripple-counter must be
taken into account. Therefore, it is necessary for T1CKI
to have a period of at least 4Tosc (and a small RC delay
of 40 ns) divided by the prescaler value. The only
requirement on T1CKI high and low time is that they do
not violate the minimum pulse width requirements of
10 ns). Refer to the appropriate electrical specifications, parameters 40, 42, 45, 46, and 47.
If T1SYNC is cleared, then the external clock input is
synchronized with internal phase clocks. The synchronization is done after the prescaler stage. The prescaler stage is an asynchronous ripple-counter.
In this configuration, during SLEEP mode, Timer1 will
not increment even if the external clock is present,
since the synchronization circuit is shut off. The prescaler however will continue to increment.
7.2.1
EXTERNAL CLOCK INPUT TIMING FOR
SYNCHRONIZED COUNTER MODE
When an external clock input is used for Timer1 in synchronized counter mode, it must meet certain requirements. The external clock requirement is due to
FIGURE 7-1:
TIMER1 BLOCK DIAGRAM
Set flag bit
TMR1IF on
Overflow
0
TMR1
TMR1H
Synchronized
clock input
TMR1L
1
TMR1ON
on/off
T1SYNC
T1OSC
RB6/T1OSO/T1CKI
RB7/T1OSI
1
T1OSCEN FOSC/4
Enable
Internal
Oscillator(1) Clock
Prescaler
1, 2, 4, 8
Synchronize
det
0
2
T1CKPS1:T1CKPS0
TMR1CS
SLEEP input
Note 1: When the T1OSCEN bit is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 51
PIC16F62X
FIGURE 7-2:
TIMER1 INCREMENTING EDGE
T1CKI
(Default high)
T1CKI
(Default low)
Note: Arrows indicate counter increments.
7.3
Timer1 Operation in Asynchronous
Counter Mode
If control bit T1SYNC (T1CON<2>) is set, the external
clock input is not synchronized. The timer continues to
increment asynchronous to the internal phase clocks.
The timer will continue to run during SLEEP and can
generate an interrupt on overflow which will wake-up
the processor. However, special precautions in software are needed to read/write the timer (Section 7.3.2).
EXAMPLE 7-1:
; All interrupts
MOVF
TMR1H,
MOVWF TMPH
MOVF
TMR1L,
MOVWF TMPL
MOVF
TMR1H,
SUBWF TMPH,
In asynchronous counter mode, Timer1 can not be
used as a time-base for capture or compare operations.
7.3.1
EXTERNAL CLOCK INPUT TIMING WITH
UNSYNCHRONIZED CLOCK
If control bit T1SYNC is set, the timer will increment
completely asynchronously. The input clock must meet
certain minimum high time and low time requirements.
Refer to the appropriate Electrical Specifications Section, timing parameters 45, 46, and 47.
7.3.2
READING AND WRITING TIMER1 IN
ASYNCHRONOUS COUNTER MODE
Reading TMR1H or TMR1L while the timer is running,
from an external asynchronous clock, will guarantee a
valid read (taken care of in hardware). However, the
user should keep in mind that reading the 16-bit timer
in two 8-bit values itself poses certain problems since
the timer may overflow between the reads.
For writes, it is recommended that the user simply stop
the timer and write the desired values. A write contention may occur by writing to the timer registers while the
register is incrementing. This may produce an unpredictable value in the timer register.
Reading the 16-bit value requires some care.
Example 7-1 is an example routine to read the 16-bit
timer value. This is useful if the timer cannot be
stopped.
READING A 16-BIT
FREE-RUNNING TIMER
BTFSC
GOTO
are disabled
W ;Read high byte
;
W ;Read low byte
;
W ;Read high byte
W ;Sub 1st read
; with 2nd read
STATUS,Z ;Is result = 0
CONTINUE ;Good 16-bit read
;
; TMR1L may have rolled over between the read
; of the high and low bytes. Reading the high
; and low bytes now will read a good value.
;
MOVF
TMR1H, W ;Read high byte
MOVWF TMPH
;
MOVF
TMR1L, W ;Read low byte
MOVWF TMPL
;
; Re-enable the Interrupt (if required)
CONTINUE
;Continue with your code
7.4
Timer1 Oscillator
A crystal oscillator circuit is built in between pins T1OSI
(input) and T1OSO (amplifier output). It is enabled by
setting control bit T1OSCEN (T1CON<3>). The oscillator is a low power oscillator rated up to 200 kHz. It will
continue to run during SLEEP. It is primarily intended
for a 32 kHz crystal. Table 7-1 shows the capacitor
selection for the Timer1 oscillator.
The Timer1 oscillator is identical to the LP oscillator.
The user must provide a software time delay to ensure
proper oscillator start-up.
TABLE 7-1:
CAPACITOR SELECTION FOR
THE TIMER1 OSCILLATOR
Osc Type
Freq
C1
C2
LP
32 kHz
100 kHz
200 kHz
33 pF
15 pF
15 pF
33 pF
15 pF
15 pF
These values are for design guidance only.
DS40300B-page 52
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
7.5
Resetting Timer1 using a CCP Trigger
Output
7.6
If the CCP1 module is configured in compare mode to
generate a “special event trigger" (CCP1M3:CCP1M0
= 1011), this signal will reset Timer1.
Note:
Resetting of Timer1 Register Pair
(TMR1H, TMR1L)
TMR1H and TMR1L registers are not reset to 00h on a
POR or any other reset except by the CCP1 special
event triggers.
T1CON register is reset to 00h on a Power-on Reset or
a Brown-out Reset, which shuts off the timer and
leaves a 1:1 prescale. In all other resets, the register is
unaffected.
The special event triggers from the CCP1
module will not set interrupt flag bit
TMR1IF (PIR1<0>).
Timer1 must be configured for either timer or synchronized counter mode to take advantage of this feature. If
Timer1 is running in asynchronous counter mode, this
reset operation may not work.
7.7
Timer1 Prescaler
The prescaler counter is cleared on writes to the
TMR1H or TMR1L registers.
In the event that a write to Timer1 coincides with a special event trigger from CCP1, the write will take precedence.
In this mode of operation, the CCPRxH:CCPRxL registers pair effectively becomes the period register for
Timer1.
TABLE 7-2:
Address
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Name
Value on
POR
Value on
all other
resets
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0Bh/8Bh/
INTCON
10Bh/18Bh
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0Ch
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000 0000 -000
TMR1IE
0000 -000 0000 -000
PIR1
EEIE
CMIE
RCIE
TXIE
—
CCP1IE
TMR2IE
0000 000x 0000 000u
8Ch
PIE1
0Eh
TMR1L
Holding register for the Least Significant Byte of the 16-bit TMR1 register
xxxx xxxx uuuu uuuu
0Fh
TMR1H
Holding register for the Most Significant Byte of the 16-bit TMR1 register
xxxx xxxx uuuu uuuu
10h
T1CON
Legend:
—
—
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON --00 0000 --uu uuuu
x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by the Timer1 module.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 53
PIC16F62X
8.0
TIMER2 MODULE
8.1
Timer2 is an 8-bit timer with a prescaler and a
postscaler. It can be used as the PWM time-base for
PWM mode of the CCP module. The TMR2 register is
readable and writable, and is cleared on any device
reset.
The input clock (FOSC/4) has a prescale option of 1:1,
1:4
or
1:16,
selected
by
control
bits
T2CKPS1:T2CKPS0 (T2CON<1:0>).
The Timer2 module has an 8-bit period register PR2.
Timer2 increments from 00h until it matches PR2 and
then resets to 00h on the next increment cycle. PR2 is
a readable and writable register. The PR2 register is initialized to FFh upon reset.
The match output of TMR2 goes through a 4-bit
postscaler (which gives a 1:1 to 1:16 scaling inclusive)
to generate a TMR2 interrupt (latched in flag bit
TMR2IF, (PIR1<1>)).
Timer2 Prescaler and Postscaler
The prescaler and postscaler counters are cleared
when any of the following occurs:
• a write to the TMR2 register
• a write to the T2CON register
• any device reset (Power-on Reset, MCLR reset,
Watchdog Timer reset, or Brown-out Reset)
TMR2 is not cleared when T2CON is written.
8.2
Output of TMR2
The output of TMR2 (before the postscaler) is fed to the
Synchronous Serial Port module which optionally uses
it to generate shift clock.
FIGURE 8-1:
Sets flag
bit TMR2IF
TIMER2 BLOCK DIAGRAM
TMR2
output (1)
Reset
Timer2 can be shut off by clearing control bit TMR2ON
(T2CON<2>) to minimize power consumption.
Postscaler
1:1 to 1:16
Register 8-1 shows the Timer2 control register.
4
EQ
TMR2 reg
Comparator
Prescaler
1:1, 1:4, 1:16
FOSC/4
2
PR2 reg
Note 1: TMR2 register output can be software selected
by the SSP Module as a baud clock.
DS40300B-page 54
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
REGISTER 8-1: T2CON: TIMER2 CONTROL REGISTER (ADDRESS 12h)
U-0
—
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON
bit7
bit0
bit 7:
Unimplemented: Read as '0'
bit 6-3:
TOUTPS3:TOUTPS0: Timer2 Output Postscale Select bits
0000 = 1:1 Postscale
0001 = 1:2 Postscale
•
•
•
1111 = 1:16 Postscale
bit 2:
TMR2ON: Timer2 On bit
1 = Timer2 is on
0 = Timer2 is off
bit 1-0:
T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits
00 = Prescaler is 1
01 = Prescaler is 4
1x = Prescaler is 16
TABLE 8-1:
Address
R/W-0
T2CKPS1 T2CKPS0
Name
0Bh/8Bh/
INTCON
10Bh/18Bh
R = Readable bit
W = Writable bit
U = Unimplemented bit,
read as ‘0’
- n = Value at POR reset
REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER
Value on
POR
Value on
all other
resets
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x 0000 000u
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000 0000 -000
8Ch
PIE1
EEIE
CMIE
RCIE
TXIE
—
CCP1IE
TMR2IE
TMR1IE
0000 -000 0000 -000
11h
TMR2
12h
T2CON
92h
Legend:
PR2
0000 0000 0000 0000
Timer2 module’s register
—
TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1
T2CKPS0 -000 0000 -000 0000
1111 1111 1111 1111
Timer2 Period Register
x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by the Timer2 module.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 55
PIC16F62X
NOTES:
DS40300B-page 56
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
9.0
COMPARATOR MODULE
The comparator module contains two analog
comparators. The inputs to the comparators are
multiplexed with the RA0 through RA3 pins. The
on-chip Voltage Reference (Section 11.0) can also be
an input to the comparators.
REGISTER 9-1:
R-0
C2OUT
bit7
bit 7:
R-0
C1OUT
The CMCON register, shown in Register 9-1, controls
the comparator input and output multiplexers. A block
diagram of the comparator is shown in Figure 9-1.
CMCON REGISTER (ADDRESS 01Fh)
R/W-0
C2INV
R/W-0
C1INV
R/W-0
CIS
R/W-0
CM2
R/W-0
CM1
R/W-0
CM0
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit, read
as ’0’
-n = Value at POR reset
C2OUT: Comparator 2 output
When C2INV=0;
1 = C2 VIN+ > C2 VIN–
0 = C2 VIN+ < C2 VIN–
When C2INV=1;
0 = C2 VIN+ > C2 VIN–
1 = C2 VIN+ < C2 VIN–
bit 6:
C1OUT: Comparator 1 output
When C1INV=0;
1 = C1 VIN+ > C1 VIN–
0 = C1 VIN+ < C1 VIN–
When C1INV=1;
0 = C1 VIN+ > C1 VIN–
1 = C1 VIN+ < C1 VIN–
bit 5:
C2INV: Comparator 2 output inversion
1 = C2 Output inverted
0 = C2 Output not inverted
bit 4:
C1INV: Comparator 1 output inversion
1 = C1 Output inverted
0 = C1 Output not inverted
bit 3:
CIS: Comparator Input Switch
When CM2:CM0: = 001:
Then:
1 = C1 VIN– connects to RA3
0 = C1 VIN– connects to RA0
When CM2:CM0 = 010:
Then:
1 = C1 VIN– connects to RA3
C2 VIN– connects to RA2
0 = C1 VIN– connects to RA0
C2 VIN– connects to RA1
bit 2-0: CM2:CM0: Comparator mode
Figure 9-1 shows the comparator modes and CM2:CM0 bit settings.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 57
PIC16F62X
9.1
Comparator Configuration
There are eight modes of operation for the
comparators. The CMCON register is used to select
the mode. Figure 9-1 shows the eight possible modes.
The TRISA register controls the data direction of the
comparator pins for each mode. If the comparator
FIGURE 9-1:
A
Comparator interrupts should be disabled
during a comparator mode change otherwise a false interrupt may occur.
Comparators Off
CM2:CM0 = 111
Vin-
RA3/AN3/C10
A
Vin+
RA1/AN1
A
Vin-
RA2/AN2
Note:
COMPARATOR I/O OPERATING MODES
Comparators Reset (POR Default Value)
CM2:CM0 = 000
RA0/AN0
mode is changed, the comparator output level may not
be valid for the specified mode change delay shown
in Table 12-2.
Vin+
A
C1
Off (Read as ’0’)
C2
Off (Read as ’0’)
A
Vin-
RA3/AN3/C10
A
Vin+
RA1/AN1
A
Vin-
RA2/AN2
A
Vin+
D
Vin-
RA3/AN3/C10
D
Vin+
D
Vin-
D
Vin+
RA1/AN1
RA2/AN2
C1
Off (Read as ’0’)
C2
Off (Read as ’0’)
Four Inputs Multiplexed to Two Comparators
CM2:CM0 = 010
Two Independent Comparators
CM2:CM0 = 100
RA0/AN0
RA0/AN0
C1
C2
C1OUT
RA0/AN0
A
RA3/AN3/C10
A
RA1/AN1
A
RA2/AN2
A
CIS = 0
CIS = 1
Vin-
CIS = 0
CIS = 1
Vin-
C2OUT
Vin+
Vin+
C1
C1OUT
C2
C2OUT
From Vref Module
Two Common Reference Comparators
CM2:CM0 = 011
A
Vin-
D
Vin+
RA1/AN1
A
Vin-
RA2/AN2
A
Vin+
RA0/AN0
RA3/AN3/C10
Two Common Reference Comparators with Outputs
CM2:CM0 = 110
A
Vin-
RA3/AN3/C10
D
Vin+
RA1/AN1
A
Vin-
RA2/AN2
A
Vin+
RA0/AN0
C1
C2
C1OUT
C2OUT
RA0/AN0
D
Vin-
RA3/AN3/C10
D
Vin+
RA1/AN1
A
Vin-
RA2/AN2
A
Vin+
C1OUT
C2
C2OUT
Open Drain
RA4/T0CKI/C20
One Independent Comparator
CM2:CM0 = 101
C1
Three Inputs Multiplexed to Two Comparators
CM2:CM0 = 001
C1
C2
Off (Read as ’0’)
C2OUT
RA0/AN0
A
RA3/AN3/C10 A
CIS = 0
CIS = 1
VinVin+
RA1/AN1
A
Vin-
RA2/AN2
A
Vin+
C1
C1OUT
C2
C2OUT
A = Analog Input, port reads zeros always.
D = Digital Input.
CIS (CMCON<3>) is the Comparator Input Switch.
DS40300B-page 58
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
The code example in Example 9-1 depicts the steps
required to configure the comparator module. RA3 and
RA4 are configured as digital output. RA0 and RA1 are
configured as the V- inputs and RA2 as the V+ input to
both comparators.
EXAMPLE 9-1:
FLAG_REG
CLRF
CLRF
MOVF
ANDLW
IORWF
MOVLW
MOVWF
BSF
MOVLW
MOVWF
BCF
CALL
MOVF
BCF
BSF
BSF
BCF
BSF
BSF
9.2
INITIALIZING
COMPARATOR MODULE
9.3
Comparator Reference
An external or internal reference signal may be used
depending on the comparator operating mode. The
analog signal that is present at VIN– is compared to the
signal at VIN+, and the digital output of the comparator
is adjusted accordingly (Figure 9-2).
FIGURE 9-2:
EQU
FLAG_REG
PORTA
CMCON, W
0xC0
FLAG_REG,F
0x03
CMCON
STATUS,RP0
0x07
TRISA
0X20
;Init flag register
;Init PORTA
;Load comparator bits
;Mask comparator bits
;Store bits in flag register
;Init comparator mode
;CM<2:0> = 011
;Select Bank1
;Initialize data direction
;Set RA<2:0> as inputs
;RA<4:3> as outputs
;TRISA<7:5> always read ‘0’
STATUS,RP0 ;Select Bank 0
DELAY 10
;10µs delay
CMCON,F
;Read CMCON to end change condition
PIR1,CMIF
;Clear pending interrupts
STATUS,RP0 ;Select Bank 1
PIE1,CMIE
;Enable comparator interrupts
STATUS,RP0 ;Select Bank 0
INTCON,PEIE ;Enable peripheral interrupts
INTCON,GIE ;Global interrupt enable
Comparator Operation
VIN–
+
–
Output
VIN–
VIN+
Output
9.3.1
A single comparator is shown in Figure 9-2 along with
the relationship between the analog input levels and
the digital output. When the analog input at VIN+ is less
than the analog input VIN–, the output of the
comparator is a digital low level. When the analog input
at VIN+ is greater than the analog input VIN–, the output
of the comparator is a digital high level. The shaded
areas of the output of the comparator in Figure 9-2
represent the uncertainty due to input offsets and
response time.
 1999 Microchip Technology Inc.
VIN+
SINGLE COMPARATOR
EXTERNAL REFERENCE SIGNAL
When external voltage references are used, the
comparator module can be configured to have the comparators operate from the same or different reference
sources. However, threshold detector applications may
require the same reference. The reference signal must
be between VSS and VDD, and can be applied to either
pin of the comparator(s).
9.3.2
INTERNAL REFERENCE SIGNAL
The comparator module also allows the selection of an
internally generated voltage reference for the
comparators. Section 13, Instruction Sets, contains a
detailed description of the Voltage Reference Module
that provides this signal. The internal reference signal
is used when the comparators are in mode
CM<2:0>=010 (Figure 9-1). In this mode, the internal
voltage reference is applied to the VIN+ pin of both
comparators.
Preliminary
DS40300B-page 59
PIC16F62X
9.4
Comparator Response Time
9.5
Response time is the minimum time, after selecting a
new reference voltage or input source, before the
comparator output is guaranteed to have a valid level.
If the internal reference is changed, the maximum delay
of the internal voltage reference must be considered
when using the comparator outputs. Otherwise the
maximum delay of the comparators should be used
(Table 12-2 ).
Comparator Outputs
The comparator outputs are read through the CMCON
register. These bits are read only. The comparator
outputs may also be directly output to the RA3 and RA4
I/O pins. When the CM<2:0> = 110 or 001, multiplexors
in the output path of the RA3 and RA4/T0CK1 pins will
switch and the output of each pin will be the unsynchronized output of the comparator. The uncertainty of each
of the comparators is related to the input offset voltage
and the response time given in the specifications.
Figure 9-3 shows the comparator output block diagram.
The TRISA bits will still function as an output
enable/disable for the RA3 and RA4/T0CK1 pins while
in this mode.
Note 1: When reading the PORT register, all pins
configured as analog inputs will read as
a ‘0’. Pins configured as digital inputs will
convert an analog input according to the
Schmitt Trigger input specification.
2: Analog levels on any pin that is defined
as a digital input may cause the input
buffer to consume more current than is
specified.
FIGURE 9-3:
MODIFIED COMPARATOR OUTPUT BLOCK DIAGRAM
Port Pins
MULTIPLEX
CnINV
To RA3 or RA4/T0CK1 pin
To Data Bus
Q
D
Q1
EN
RD CMCON
Q
Set CMIF bit
D
Q3 * RD CMCON
EN
CL
From other Comparator
DS40300B-page 60
NRESET
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
9.6
Comparator Interrupts
wake up the device from SLEEP mode when enabled.
While the comparator is powered-up, higher sleep
currents than shown in the power down current
specification will occur. Each comparator that is
operational will consume additional current as shown in
the comparator specifications. To minimize power
consumption while in SLEEP mode, turn off the
comparators, CM<2:0> = 111, before entering sleep. If
the device wakes-up from sleep, the contents of the
CMCON register are not affected.
The comparator interrupt flag is set whenever there is
a change in the output value of either comparator.
Software will need to maintain information about the
status of the output bits, as read from CMCON<7:6>, to
determine the actual change that has occurred. The
CMIF bit, PIR1<6>, is the comparator interrupt flag.
The CMIF bit must be reset by clearing ‘0’. Since it is
also possible to write a '1' to this register, a simulated
interrupt may be initiated.
9.8
The CMIE bit (PIE1<6>) and the PEIE bit
(INTCON<6>) must be set to enable the interrupt. In
addition, the GIE bit must also be set. If any of these
bits are clear, the interrupt is not enabled, though the
CMIF bit will still be set if an interrupt condition occurs.
Note:
A device reset forces the CMCON register to its reset
state. This forces the comparator module to be in the
comparator reset mode, CM2:CM0 = 000. This
ensures that all potential inputs are analog inputs.
Device current is minimized when analog inputs are
present at reset time. The comparators will be
powered-down during the reset interval.
If a change in the CMCON register
(C1OUT or C2OUT) should occur when a
read operation is being executed (start of
the Q2 cycle), then the CMIF (PIR1<6>)
interrupt flag may not get set.
9.9
The user, in the interrupt service routine, can clear the
interrupt in the following manner:
a)
b)
Comparator Operation During SLEEP
When a comparator is active and the device is placed
in SLEEP mode, the comparator remains active and
the interrupt is functional if enabled. This interrupt will
FIGURE 9-4:
Analog Input Connection
Considerations
A simplified circuit for an analog input is shown in
Figure 9-4. Since the analog pins are connected to a
digital output, they have reverse biased diodes to VDD
and VSS. The analog input therefore, must be between
VSS and VDD. If the input voltage deviates from this
range by more than 0.6V in either direction, one of the
diodes is forward biased and a latch-up may occur. A
maximum
source
impedance
of
10 kΩ
is
recommended for the analog sources. Any external
component connected to an analog input pin, such as
a capacitor or a Zener diode, should have very little
leakage current.
Any read or write of CMCON. This will end the
mismatch condition.
Clear flag bit CMIF.
A mismatch condition will continue to set flag bit CMIF.
Reading CMCON will end the mismatch condition, and
allow flag bit CMIF to be cleared.
9.7
Effects of a RESET
ANALOG INPUT MODEL
VDD
VT = 0.6V
RS < 10K
RIC
AIN
CPIN
5 pF
VA
VT = 0.6V
ILEAKAGE
±500 nA
VSS
Legend
CPIN
VT
ILEAKAGE
RIC
RS
VA
 1999 Microchip Technology Inc.
= Input Capacitance
= Threshold Voltage
= Leakage Current At The Pin Due To Various Junctions
= Interconnect Resistance
= Source Impedance
= Analog Voltage
Preliminary
DS40300B-page 61
PIC16F62X
TABLE 9-1:
Address
Name
1Fh
9Fh
REGISTERS ASSOCIATED WITH COMPARATOR MODULE
Value on
POR
Value on
All Other
Resets
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
CMCON
C2OUT
C1OUT
C2INV
C1NV
CIS
CM2
CM1
CM0
0000 0000 0000 0000
VRCON
VREN
VROE
VRR
—
VR3
VR2
VR1
VR0
000- 0000 000- 0000
0Bh/8Bh/
INTCON
10Bh/18Bh
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x 0000 000u
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF TMR2IF TMR1IF 0000 -000 0000 -000
8Ch
PIE1
EEIE
CMIE
RCIE
TXIE
—
CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000
85h
TRISA
—
TRISA4
TRISA3
TRISA7 TRISA6
TRISA2
TRISA1
TRISA0
11-1 1111 11-1 1111
Legend: x = unknown, u = unchanged, - = unimplemented, read as "0"
DS40300B-page 62
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
10.0
CAPTURE/COMPARE/PWM
(CCP) MODULE
Additional information on the CCP module is available
in the PICmicro™ Mid-Range Reference Manual,
(DS33023).
The CCP (Capture/Compare/PWM) module contains a
16-bit register which can operate as a 16-bit capture
register, as a 16-bit compare register or as a PWM
master/slave Duty Cycle register. Table 10-1 shows the
timer resources of the CCP module modes.
TABLE 10-1
CCP1 Module
Capture/Compare/PWM Register1 (CCPR1) is comprised of two 8-bit registers: CCPR1L (low byte) and
CCPR1H (high byte). The CCP1CON register controls
the operation of CCP1. All are readable and writable.
CCP MODE - TIMER
RESOURCE
CCP Mode
Timer Resource
Capture
Compare
PWM
Timer1
Timer1
Timer2
REGISTER 10-1: CCP1CON REGISTER (ADDRESS 17h)
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
CCP1X
CCP1Y
CCP1M3
CCP1M2
CCP1M1
CCP1M0
bit7
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit, read
as ’0’
-n = Value at POR reset
bit 7-6: Unimplemented: Read as '0'
bit 5-4: CCP1X:CCP1Y: PWM Least Significant bits
Capture Mode: Unused
Compare Mode: Unused
PWM Mode: These bits are the two LSbs of the PWM duty cycle. The eight MSbs are found in CCPRxL.
bit 3-0: CCP1M3:CCP1M0: CCPx Mode Select bits
0000 = Capture/Compare/PWM off (resets CCP1 module)
0100 = Capture mode, every falling edge
0101 = Capture mode, every rising edge
0110 = Capture mode, every 4th rising edge
0111 = Capture mode, every 16th rising edge
1000 = Compare mode, set output on match (CCP1IF bit is set)
1001 = Compare mode, clear output on match (CCP1IF bit is set)
1010 = Compare mode, generate software interrupt on match (CCP1IF bit is set, CCP1 pin is unaffected)
1011 = Compare mode, trigger special event (CCP1IF bit is set; CCP1 resets TMR1
11xx = PWM mode
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 63
PIC16F62X
10.1
Capture Mode
10.1.4
In Capture mode, CCPR1H:CCPR1L captures the
16-bit value of the TMR1 register when an event occurs
on pin RB3/CCP1. An event is defined as:
•
•
•
•
every falling edge
every rising edge
every 4th rising edge
every 16th rising edge
An event is selected by control bits CCP1M3:CCP1M0
(CCP1CON<3:0>). When a capture is made, the interrupt request flag bit CCP1IF (PIR1<2>) is set. It must
be cleared in software. If another capture occurs before
the value in register CCPR1 is read, the old captured
value will be lost.
10.1.1
CCP PIN CONFIGURATION
In Capture mode, the RB3/CCP1 pin should be configured as an input by setting the TRISB<3> bit.
Note:
If the RB3/CCP1 is configured as an output, a write to the port can cause a capture
condition.
CCP PRESCALER
There are four prescaler settings, specified by bits
CCP1M3:CCP1M0. Whenever the CCP module is
turned off, or the CCP module is not in capture mode,
the prescaler counter is cleared. This means that any
reset will clear the prescaler counter.
Switching from one capture prescaler to another may
generate an interrupt. Also, the prescaler counter will
not be cleared, therefore the first capture may be from
a non-zero prescaler. Example 10-1 shows the recommended method for switching between capture prescalers. This example also clears the prescaler counter
and will not generate the “false” interrupt.
EXAMPLE 10-1: CHANGING BETWEEN
CAPTURE PRESCALERS
CLRF
MOVLW
CCP1CON
NEW_CAPT_PS
MOVWF
CCP1CON
;Turn CCP module off
;Load the W reg with
; the new prescaler
; mode value and CCP ON
;Load CCP1CON with this
; value
FIGURE 10-1: CAPTURE MODE OPERATION
BLOCK DIAGRAM
Prescaler
³ 1, 4, 16
Set flag bit CCP1IF
(PIR1<2>)
RB3/CCP1
Pin
CCPR1H
and
edge detect
CCPR1L
Capture
Enable
TMR1H
TMR1L
CCP1CON<3:0>
Q’s
10.1.2
TIMER1 MODE SELECTION
Timer1 must be running in timer mode or synchronized
counter mode for the CCP module to use the capture
feature. In asynchronous counter mode, the capture
operation may not work.
10.1.3
SOFTWARE INTERRUPT
When the Capture mode is changed, a false capture
interrupt may be generated. The user should keep bit
CCP1IE (PIE1<2>) clear to avoid false interrupts and
should clear the flag bit CCP1IF following any such
change in operating mode.
DS40300B-page 64
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
10.2
10.2.1
Compare Mode
The user must configure the RB3/CCP1 pin as an output by clearing the TRISB<3> bit.
In Compare mode, the 16-bit CCPR1 register value is
constantly compared against the TMR1 register pair
value. When a match occurs, the RB3/CCP1 pin is:
Note:
• driven High
• driven Low
• remains Unchanged
10.2.2
The action on the pin is based on the value of control
bits CCP1M3:CCP1M0 (CCP1CON<3:0>). At the
same time, interrupt flag bit CCP1IF is set.
10.2.3
10.2.4
SOFTWARE INTERRUPT MODE
SPECIAL EVENT TRIGGER
In this mode, an internal hardware trigger is generated
which may be used to initiate an action.
Special Event Trigger (CCP2 only)
Set flag bit CCP1IF
(PIR1<2>)
CCPR1H CCPR1L
TABLE 10-2
TIMER1 MODE SELECTION
When generate software interrupt is chosen the CCP1
pin is not affected. Only a CCP interrupt is generated (if
enabled).
Special event trigger will reset Timer1, but not
set interrupt flag bit TMR1IF (PIR1<0>)
The special event trigger output of CCP1 resets the
TMR1 register pair. This allows the CCPR1 register to
effectively be a 16-bit programmable period register for
Timer1.
Comparator
TMR1H
Clearing the CCP1CON register will force
the RB3/CCP1 compare output latch to the
default low level. This is not the data latch.
Timer1 must be running in Timer mode or Synchronized Counter mode if the CCP module is using the
compare feature. In Asynchronous Counter mode, the
compare operation may not work.
FIGURE 10-2: COMPARE MODE
OPERATION BLOCK
DIAGRAM
Q S Output
Logic
match
RB3/CCP1
R
Pin
TRISB<3>
Output Enable CCP1CON<3:0>
Mode Select
CCP PIN CONFIGURATION
TMR1L
REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, AND TIMER1
Value on
POR
Value on
all other
resets
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0Bh/8Bh/1
0Bh/18Bh
INTCON
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF 0000 -000 0000 -000
8Ch
PIE1
EEIE
CMIF
RCIE
TXIE
—
CCP1IE
TMR2IE
TMR1IE 0000 -000 0000 -000
87h
TRISB
PORTB Data Direction Register
1111 1111 1111 1111
0Eh
TMR1L
Holding register for the Least Significant Byte of the 16-bit TMR1 register
xxxx xxxx uuuu uuuu
0Fh
TMR1H
Holding register for the Most Significant Byte of the 16-bit TMR1register
xxxx xxxx uuuu uuuu
10h
T1CON
15h
CCPR1L
Capture/Compare/PWM register1 (LSB)
xxxx xxxx uuuu uuuu
16h
CCPR1H
Capture/Compare/PWM register1 (MSB)
xxxx xxxx uuuu uuuu
17h
CCP1CON
Legend:
—
—
—
—
0000 000x 0000 000u
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON --00 0000 --uu uuuu
CCP1X
CCP1Y
CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000
x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by Capture and Timer1.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 65
PIC16F62X
10.3
10.3.1
PWM Mode
In Pulse Width Modulation (PWM) mode, the CCP1 pin
produces up to a 10-bit resolution PWM output. Since
the CCP1 pin is multiplexed with the PORTC data latch,
the TRISB<3> bit must be cleared to make the CCP1
pin an output.
Note:
Clearing the CCP1CON register will force
the CCP1 PWM output latch to the default
low level. This is not the PORTB I/O data
latch.
Figure 10-3 shows a simplified block diagram of the
CCP module in PWM mode.
For a step by step procedure on how to set up the CCP
module for PWM operation, see Section 10.3.3.
FIGURE 10-3: SIMPLIFIED PWM BLOCK
DIAGRAM
Duty cycle registers
The PWM period is specified by writing to the PR2 register. The PWM period can be calculated using the following formula:
PWM period = [(PR2) + 1] • 4 • TOSC •
(TMR2 prescale value)
PWM frequency is defined as 1 / [PWM period].
When TMR2 is equal to PR2, the following three events
occur on the next increment cycle:
• TMR2 is cleared
• The CCP1 pin is set (exception: if PWM duty
cycle = 0%, the CCP1 pin will not be set)
• The PWM duty cycle is latched from CCPR1L into
CCPR1H
Note:
CCP1CON<5:4>
CCPR1L
10.3.2
CCPR1H (Slave)
R
Comparator
Q
RB3/CCP1
(Note 1)
TMR2
S
Clear Timer,
CCP1 pin and
latch D.C.
PR2
PWM DUTY CYCLE
The PWM duty cycle is specified by writing to the
CCPR1L register and to the CCP1CON<5:4> bits. Up
to 10-bit resolution is available: the CCPR1L contains
the eight MSbs and the CCP1CON<5:4> contains the
two LSbs. This 10-bit value is represented by
CCPR1L:CCP1CON<5:4>. The following equation is
used to calculate the PWM duty cycle in time:
CCPR1L and CCP1CON<5:4> can be written to at any
time, but the duty cycle value is not latched into
CCPR1H until after a match between PR2 and TMR2
occurs (i.e., the period is complete). In PWM mode,
CCPR1H is a read-only register.
Note 1: 8-bit timer is concatenated with 2-bit internal Q clock
or 2 bits of the prescaler to create 10-bit time-base.
A PWM output (Figure 10-4) has a time base (period)
and a time that the output stays high (duty cycle). The
frequency of the PWM is the inverse of the period
(1/period).
FIGURE 10-4: PWM OUTPUT
The Timer2 postscaler (see Section 8.0) is
not used in the determination of the PWM
frequency. The postscaler could be used to
have a servo update rate at a different frequency than the PWM output.
PWM duty cycle = (CCPR1L:CCP1CON<5:4>) •
Tosc • (TMR2 prescale value)
TRISB<3>
Comparator
PWM PERIOD
The CCPR1H register and a 2-bit internal latch are
used to double buffer the PWM duty cycle. This double
buffering is essential for glitchless PWM operation.
When the CCPR1H and 2-bit latch match TMR2 concatenated with an internal 2-bit Q clock or 2 bits of the
TMR2 prescaler, the CCP1 pin is cleared.
Maximum PWM resolution (bits) for a given PWM
frequency:
Period
log
(
Fosc
Fpwm
=
Duty Cycle
)
bits
log (2)
TMR2 = PR2
TMR2 = Duty Cycle
Note:
TMR2 = PR2
If the PWM duty cycle value is longer than
the PWM period the CCP1 pin will not be
cleared.
For an example PWM period and duty cycle calculation, see the PICmicro™ Mid-Range Reference Manual
(DS33023).
DS40300B-page 66
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
10.3.3
SET-UP FOR PWM OPERATION
The following steps should be taken when configuring
the CCP module for PWM operation:
1.
2.
3.
4.
5.
Set the PWM period by writing to the PR2 register.
Set the PWM duty cycle by writing to the
CCPR1L register and CCP1CON<5:4> bits.
Make the CCP1 pin an output by clearing the
TRISB<3> bit.
Set the TMR2 prescale value and enable Timer2
by writing to T2CON.
Configure the CCP1 module for PWM operation.
TABLE 10-3
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 20 MHz
PWM Frequency
1.22 kHz 4.88 kHz 19.53 kHz 78.12 kHz 156.3 kHz 208.3 kHz
Timer Prescaler (1, 4, 16)
PR2 Value
Maximum Resolution (bits)
TABLE 10-4
16
0xFF
10
4
0xFF
10
1
0xFF
10
1
0x3F
8
1
0x1F
7
1
0x17
5.5
REGISTERS ASSOCIATED WITH PWM AND TIMER2
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Value on
all other
resets
0Bh/8Bh/
10Bh/18Bh
INTCON
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x
0000 000u
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
0000 -000
8Ch
PIE1
EEIE
CMIE
RCIE
TXIE
—
CCP1IE
TMR2IE
TMR1IE
0000 -000
0000 -000
87h
TRISB
PORTB Data Direction Register
1111 1111
1111 1111
11h
TMR2
Timer2 module’s register
0000 0000
0000 0000
92h
PR2
Timer2 module’s period register
1111 1111
1111 1111
12h
T2CON
-000 0000
uuuu uuuu
15h
CCPR1L
Capture/Compare/PWM register1 (LSB)
xxxx xxxx
uuuu uuuu
16h
CCPR1H
Capture/Compare/PWM register1 (MSB)
xxxx xxxx
uuuu uuuu
17h
CCP1CON
CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000
--00 0000
Legend:
—
—
TOUTPS TOUTPS TOUTPS TOUTPS TMR2ON T2CKPS T2CKPS
3
2
1
0
1
0
—
CCP1X
CCP1Y
x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by PWM and Timer2.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 67
PIC16F62X
NOTES:
DS40300B-page 68
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
11.0
VOLTAGE REFERENCE
MODULE
11.1
The Voltage Reference can output 16 distinct voltage
levels for each range.
The Voltage Reference is a 16-tap resistor ladder
network that provides a selectable voltage reference.
The resistor ladder is segmented to provide two ranges
of VREF values and has a power-down function to
conserve power when the reference is not being used.
The VRCON register controls the operation of the
reference as shown in Figure 11-1. The block diagram
is given in Figure 11-2.
FIGURE 11-1:
R/W-0
VREN
bit7
Configuring the Voltage Reference
The equations used to calculate the output of the
Voltage Reference are as follows:
if VRR = 1: VREF = (VR<3:0>/24) x VDD
if VRR = 0: VREF = (VDD x 1/4) + (VR<3:0>/32) x VDD
The setting time of the Voltage Reference must be
considered when changing the VREF output
(Table 12-2). Example 11-1 shows an example of how
to configure the Voltage Reference for an output voltage of 1.25V with VDD = 5.0V.
VRCON REGISTER(ADDRESS 9Fh)
R/W-0
VROE
R/W-0
VRR
U-0
—
R/W-0
VR3
R/W-0
VR2
bit 7:
VREN: VREF Enable
1 = VREF circuit powered on
0 = VREF circuit powered down, no IDD drain
bit 6:
VROE: VREF Output Enable
1 = VREF is output on RA2 pin
0 = VREF is disconnected from RA2 pin
bit 5:
VRR: VREF Range selection
1 = Low Range
0 = High Range
bit 4:
Unimplemented: Read as '0'
R/W-0
VR1
R/W-0
VR0
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit, read
as ’0’
-n = Value at POR reset
bit 3-0: VR<3:0>: VREF value selection 0 ≤ VR [3:0] ≤ 15
when VRR = 1: VREF = (VR<3:0>/ 24) * VDD
when VRR = 0: VREF = 1/4 * VDD + (VR<3:0>/ 32) * VDD
FIGURE 11-2: VOLTAGE REFERENCE BLOCK DIAGRAM
16 Stages
VREN
8R
R
R
R
R
8R
VRR
VR3
VREF
(From VRCON<3:0>)
16-1 Analog Mux
VR0
Note:
R is defined in Table 12-3.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 69
PIC16F62X
EXAMPLE 11-1: VOLTAGE REFERENCE
CONFIGURATION
MOVLW
0x02
11.4
A device reset disables the Voltage Reference by clearing bit VREN (VRCON<7>). This reset also disconnects
the reference from the RA2 pin by clearing bit VROE
(VRCON<6>) and selects the high voltage range by
clearing bit VRR (VRCON<5>). The VREF value select
bits, VRCON<3:0>, are also cleared.
; 4 Inputs Muxed
MOVWF
CMCON
; to 2 comps.
BSF
STATUS,RP0
; go to Bank 1
MOVLW
0x07
; RA3-RA0 are
MOVWF
TRISA
; outputs
MOVLW
0xA6
; enable VREF
MOVWF
VRCON
; low range
BCF
STATUS,RP0
; go to Bank 0
CALL
DELAY10
; 10µs delay
11.5
Voltage Reference Accuracy/Error
The full range of VSS to VDD cannot be realized due to
the construction of the module. The transistors on the
top and bottom of the resistor ladder network
(Figure 11-2) keep VREF from approaching VSS or VDD.
The Voltage Reference is VDD derived and therefore,
the VREF output changes with fluctuations in VDD. The
tested absolute accuracy of the Voltage Reference can
be found in Table 17-2.
11.3
Connection Considerations
The
Voltage
Reference
Module
operates
independently of the comparator module. The output of
the reference generator may be connected to the RA2
pin if the TRISA<2> bit is set and the VROE bit,
VRCON<6>, is set. Enabling the Voltage Reference
output onto the RA2 pin with an input signal present will
increase current consumption. Connecting RA2 as a
digital output with VREF enabled will also increase
current consumption.
; set VR<3:0>=6
11.2
Effects of a Reset
The RA2 pin can be used as a simple D/A output with
limited drive capability. Due to the limited drive
capability, a buffer must be used in conjunction with the
Voltage Reference output for external connections to
VREF. Figure 11-3 shows an example buffering
technique.
Operation During Sleep
When the device wakes up from sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the VRCON register are not affected. To minimize
current consumption in SLEEP mode, the Voltage
Reference should be disabled.
FIGURE 11-3: VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE
VREF
R(1)
RA2
•
Module
+
–
•
VREF Output
Voltage
Reference
Output
Impedance
Note 1: R is dependent upon the Voltage Reference Configuration VRCON<3:0> and VRCON<5>.
TABLE 11-1:
Address
REGISTERS ASSOCIATED WITH VOLTAGE REFERENCE
Name
Bit 7
Bit 6
VREN
VROE
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value On
POR
Value On
All Other
Resets
9Fh
VRCON
VRR
—
VR3
VR2
VR1
VR0
000- 0000
000- 0000
1Fh
CMCON
C2OUT C1OUT
C2INV
C1INV
CIS
CM2
CM1
CM0
0000 0000
0000 0000
85h
TRISA
TRISA7 TRISA6
—
TRISA4
TRISA3
TRISA2
TRISA1
TRISA0
11-1 1111
11-1 1111
Note:
- = Unimplemented, read as "0"
DS40300B-page 70
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
12.0
UNIVERSAL SYNCHRONOUS
ASYNCHRONOUS RECEIVER
TRANSMITTER (USART)
as a half duplex synchronous system that can communicate with peripheral devices such as A/D or D/A integrated circuits, Serial EEPROMs etc.
The USART can be configured in the following modes:
The Universal Synchronous Asynchronous Receiver
Transmitter (USART) module is one of the two serial
I/O modules. (USART is also known as a Serial Communications Interface or SCI). The USART can be configured as a full duplex asynchronous system that can
communicate with peripheral devices such as CRT terminals and personal computers, or it can be configured
• Asynchronous (full duplex)
• Synchronous - Master (half duplex)
• Synchronous - Slave (half duplex)
Bit SPEN (RCSTA<7>), and bits TRISB<2:1>, have
to be set in order to configure pins RB2/TX/CK and
RB1/RX/DT as the Universal Synchronous Asynchronous Receiver Transmitter.
REGISTER 12-1: TXSTA: TRANSMIT STATUS AND CONTROL REGISTER (ADDRESS 98h)
R/W-0
CSRC
bit7
bit 7:
R/W-0
TX9
R/W-0
TXEN
R/W-0
SYNC
U-0
—
R/W-0
BRGH
R-1
TRMT
R/W-0
TX9D
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit,
read as ’0’
-n = Value at POR reset
CSRC: Clock Source Select bit
Asynchronous mode
Don’t care
Synchronous mode
1 = Master mode (Clock generated internally from BRG)
0 = Slave mode (Clock from external source)
bit 6:
TX9: 9-bit Transmit Enable bit
1 = Selects 9-bit transmission
0 = Selects 8-bit transmission
bit 5:
TXEN: Transmit Enable bit
1 = Transmit enabled
0 = Transmit disabled
Note: SREN/CREN overrides TXEN in SYNC mode.
bit 4:
SYNC: USART Mode Select bit
1 = Synchronous mode
0 = Asynchronous mode
bit 3:
Unimplemented: Read as '0'
bit 2:
BRGH: High Baud Rate Select bit
Asynchronous mode
1 = High speed
0 = Low speed
Synchronous mode
Unused in this mode
bit 1:
TRMT: Transmit Shift Register Status bit
1 = TSR empty
0 = TSR full
bit 0:
TX9D: 9th bit of transmit data. Can be parity bit.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 71
PIC16F62X
REGISTER 12-2: RCSTA: RECEIVE STATUS AND CONTROL REGISTER (ADDRESS 18h)
R/W-0
SPEN
bit7
R/W-0
RX9
R/W-0
SREN
R/W-0
CREN
R/W-0
ADEN
R-0
FERR
R-0
OERR
R-x
RX9D
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit,
read as ’0’
-n = Value at POR reset
x = unknown
bit 7:
SPEN: Serial Port Enable bit
(Configures RB1/RX/DT and RB2/TX/CK pins as serial port pins when bits TRISB<2:17> are set)
1 = Serial port enabled
0 = Serial port disabled
bit 6:
RX9: 9-bit Receive Enable bit
1 = Selects 9-bit reception
0 = Selects 8-bit reception
bit 5:
SREN: Single Receive Enable bit
Asynchronous mode:
Don’t care
Synchronous mode - master:
1 = Enables single receive
0 = Disables single receive
This bit is cleared after reception is complete.
Synchronous mode - slave:
Unused in this mode
bit 4:
CREN: Continuous Receive Enable bit
Asynchronous mode:
1 = Enables continuous receive
0 = Disables continuous receive
Synchronous mode:
1 = Enables continuous receive until enable bit CREN is cleared (CREN overrides SREN)
0 = Disables continuous receive
bit 3:
ADEN: Address Detect Enable bit
Asynchronous mode 9-bit (RX9 = 1):
1 = Enables address detection, enable interrupt and load of the receive buffer when RSR<8> is set
0 = Disables address detection, all bytes are received, and ninth bit can be used as parity bit
Asynchronous mode 8-bit (RX9=0):
Unused in this mode
Synchronous mode
Unused in this mode
bit 2:
FERR: Framing Error bit
1 = Framing error (Can be updated by reading RCREG register and receive next valid byte)
0 = No framing error
bit 1:
OERR: Overrun Error bit
1 = Overrun error (Can be cleared by clearing bit CREN)
0 = No overrun error
bit 0:
RX9D: 9th bit of received data (Can be parity bit)
DS40300B-page 72
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
12.1
USART Baud Rate Generator (BRG)
EXAMPLE 12-1: CALCULATING BAUD RATE
ERROR
The BRG supports both the Asynchronous and Synchronous modes of the USART. It is a dedicated 8-bit
baud rate generator. The SPBRG register controls the
period of a free running 8-bit timer. In asynchronous
mode bit BRGH (TXSTA<2>) also controls the baud
rate. In synchronous mode bit BRGH is ignored.
Table 12-1 shows the formula for computation of the
baud rate for different USART modes which only apply
in master mode (internal clock).
Desired Baud rate = Fosc / (64 (X + 1))
16000000 /(64 (X + 1))
X
Î25.042° = 25
=
Calculated Baud Rate=16000000 / (64 (25 + 1))
=
Error
Given the desired baud rate and Fosc, the nearest integer value for the SPBRG register can be calculated
using the formula in Table 12-1. From this, the error in
baud rate can be determined.
=
9615
(Calculated Baud Rate - Desired Baud Rate)
Desired Baud Rate
=
(9615 - 9600) / 9600
=
0.16%
It may be advantageous to use the high baud rate
(BRGH = 1) even for slower baud clocks. This is
because the FOSC/(16(X + 1)) equation can reduce the
baud rate error in some cases.
Example 12-1 shows the calculation of the baud rate
error for the following conditions:
FOSC = 16 MHz
Desired Baud Rate = 9600
BRGH = 0
SYNC = 0
TABLE 12-1:
9600 =
Writing a new value to the SPBRG register, causes the
BRG timer to be reset (or cleared), this ensures the
BRG does not wait for a timer overflow before outputting the new baud rate.
BAUD RATE FORMULA
SYNC
BRGH = 0 (Low Speed)
BRGH = 1 (High Speed)
(Asynchronous) Baud Rate = FOSC/(64(X+1))
(Synchronous) Baud Rate = FOSC/(4(X+1))
X = value in SPBRG (0 to 255)
Baud Rate= FOSC/(16(X+1))
NA
0
1
TABLE 12-2:
REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR
Bit 0
Value on
POR
Value on all
other resets
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
98h
TXSTA
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D 0000 -010
0000 -010
18h
RCSTA
SPEN
RX9
SREN CREN ADEN
FERR
OERR RX9D 0000 -00x
0000 -00x
99h
SPBRG
Baud Rate Generator Register
0000 0000
0000 0000
Legend: x = unknown, - = unimplemented read as '0'. Shaded cells are not used by the BRG.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 73
PIC16F62X
TABLE 12-3:
BAUD
RATE
(K)
0.3
1.2
2.4
9.6
19.2
76.8
96
300
500
HIGH
LOW
BAUD RATES FOR SYNCHRONOUS MODE
FOSC = 20 MHz
KBAUD
NA
NA
NA
NA
19.53
76.92
96.15
294.1
500
5000
19.53
16 MHz
SPBRG
value
%
KBAUD
ERROR (decimal)
+1.73
+0.16
+0.16
-1.96
0
-
255
64
51
16
9
0
255
FOSC = 5.0688 MHz
BAUD
RATE
(K)
0.3
1.2
2.4
9.6
19.2
76.8
96
300
500
HIGH
LOW
0.3
1.2
2.4
9.6
19.2
76.8
96
300
500
HIGH
LOW
+0.16
+0.16
-0.79
+2.56
0
-
207
51
41
12
7
0
255
4 MHz
NA
NA
NA
9.766
19.23
75.76
96.15
312.5
500
2500
9.766
7.15909 MHz
SPBRG
SPBRG
value
%
%
value
KBAUD
ERROR (decimal)
ERROR (decimal)
+1.73
+0.16
-1.36
+0.16
+4.17
0
-
255
129
32
25
7
4
0
255
3.579545 MHz
NA
NA
NA
9.622
19.24
77.82
94.20
298.3
NA
1789.8
6.991
+0.23
+0.23
+1.32
-1.88
-0.57
-
1 MHz
185
92
22
18
5
0
255
32.768 kHz
SPBRG
SPBRG
SPBRG
SPBRG
SPBRG
KBAUD
%
value KBAUD
%
value
KBAUD
%
value KBAUD
%
value KBAUD
%
value
ERROR (decimal)
ERROR (decimal)
ERROR (decimal)
ERROR (decimal)
ERROR (decimal)
NA
NA
NA
9.6
19.2
79.2
97.48
316.8
NA
1267
4.950
0
0
+3.13
+1.54
+5.60
-
TABLE 12-4:
BAUD
RATE
(K)
NA
NA
NA
NA
19.23
76.92
95.24
307.69
500
4000
15.625
10 MHz
SPBRG
value
%
KBAUD
ERROR (decimal)
131
65
15
12
3
0
255
NA
NA
NA
9.615
19.231
76.923
1000
NA
NA
100
3.906
NA
1.221
2.404
9.469
19.53
78.13
104.2
312.5
NA
312.5
1.221
103
51
12
9
0
255
NA
NA
NA
9.622
19.04
74.57
99.43
298.3
NA
894.9
3.496
+0.23
-0.83
-2.90
+3.57
-0.57
-
92
46
11
8
2
0
255
NA
1.202
2.404
9.615
19.24
83.34
NA
NA
NA
250
0.9766
+0.16
+0.16
+0.16
+0.16
+8.51
-
207
103
25
12
2
0
255
0.303
1.170
NA
NA
NA
NA
NA
NA
NA
8.192
0.032
+1.14
-2.48
-
26
6
0
255
BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 0)
FOSC = 20 MHz
KBAUD
+0.16
+0.16
+0.16
+4.17
-
16 MHz
SPBRG
%
value
ERROR (decimal) KBAUD
+1.73
+0.16
-1.36
+1.73
+1.73
+8.51
+4.17
-
255
129
32
15
3
2
0
0
255
FOSC = 5.0688 MHz
NA
1.202
2.404
9.615
19.23
83.33
NA
NA
NA
250
0.977
10 MHz
SPBRG
%
value
ERROR (decimal) KBAUD
+0.16
+0.16
+0.16
+0.16
+8.51
-
207
103
25
12
2
0
255
4 MHz
NA
1.202
2.404
9.766
19.53
78.13
NA
NA
NA
156.3
0.6104
7.15909 MHz
SPBRG
SPBRG
%
value
%
value
ERROR (decimal) KBAUD ERROR (decimal)
+0.16
+0.16
+1.73
+1.73
+1.73
-
3.579545 MHz
129
64
15
7
1
0
255
NA
1.203
2.380
9.322
18.64
NA
NA
NA
NA
111.9
0.437
+0.23
-0.83
-2.90
-2.90
-
1 MHz
92
46
11
5
0
255
32.768 kHz
BAUD
RATE
(K)
SPBRG
SPBRG
SPBRG
SPBRG
SPBRG
%
value
%
value
%
value
%
value
%
value
KBAUD ERROR (decimal) KBAUD ERROR (decimal) KBAUD ERROR (decimal) KBAUD ERROR (decimal) KBAUD ERROR (decimal)
0.3
1.2
2.4
9.6
19.2
76.8
96
300
500
HIGH
LOW
0.31
1.2
2.4
9.9
19.8
79.2
NA
NA
NA
79.2
0.3094
+3.13
0
0
+3.13
+3.13
+3.13
-
DS40300B-page 74
255
65
32
7
3
0
0
255
0.3005
1.202
2.404
NA
NA
NA
NA
NA
NA
62.500
3.906
-0.17
+1.67
+1.67
-
207
51
25
0
255
0.301
1.190
2.432
9.322
18.64
NA
NA
NA
NA
55.93
0.2185
+0.23
-0.83
+1.32
-2.90
-2.90
-
Preliminary
185
46
22
5
2
0
255
0.300
1.202
2.232
NA
NA
NA
NA
NA
NA
15.63
0.0610
+0.16
+0.16
-6.99
-
51
12
6
0
255
0.256
NA
NA
NA
NA
NA
NA
NA
NA
0.512
0.0020
-14.67
-
1
0
255
 1999 Microchip Technology Inc.
PIC16F62X
TABLE 12-5:
BAUD
RATE
(K)
9.6
19.2
38.4
57.6
115.2
250
625
1250
BAUD
RATE
(K)
BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 1)
FOSC = 20 MHz
KBAUD
9.615
19.230
37.878
56.818
113.636
250
625
1250
16 MHz
SPBRG
value
%
ERROR (decimal) KBAUD
+0.16
+0.16
-1.36
-1.36
-1.36
0
0
0
129
64
32
21
10
4
1
0
9.615
19.230
38.461
58.823
111.111
250
NA
NA
10 MHz
SPBRG
value
%
ERROR (decimal) KBAUD
+0.16
+0.16
+0.16
+2.12
-3.55
0
-
103
51
25
16
8
3
-
9.615
18.939
39.062
56.818
125
NA
625
NA
7.16 MHz
SPBRG
SPBRG
value
%
%
value
ERROR (decimal) KBAUD ERROR (decimal)
+0.16
-1.36
+1.7
-1.36
+8.51
0
-
64
32
15
10
4
0
-
9.520
19.454
37.286
55.930
111.860
NA
NA
NA
-0.83
+1.32
-2.90
-2.90
-2.90
-
46
22
11
7
3
-
FOSC = 5.068 MHz
4 MHz
3.579 MHz
1 MHz
32.768 kHz
SPBRG
SPBRG
SPBRG
SPBRG
SPBRG
value
value
value
value
%
%
%
%
%
value
KBAUD ERROR (decimal) KBAUD ERROR (decimal) KBAUD ERROR (decimal) KBAUD ERROR (decimal) KBAUD ERROR (decimal)
9.6
19.2
9.6
18.645
0
-2.94
32
16
NA
1.202
38.4
57.6
115.2
250
625
1250
39.6
52.8
105.6
NA
NA
NA
+3.12
-8.33
-8.33
-
7
5
2
-
2.403
9.615
19.231
NA
NA
NA
 1999 Microchip Technology Inc.
+0.17
+0.13
+0.16
+0.16
-
207
9.727
18.643
+1.32
-2.90
22
11
8.928
20.833
-6.99
+8.51
6
2
NA
NA
-
-
103
25
12
-
37.286 -2.90
55.930 -2.90
111.860 -2.90
223.721 -10.51
NA
NA
-
5
3
1
0
-
31.25
62.5
NA
NA
NA
NA
-18.61
+8.51
-
1
0
-
NA
NA
NA
NA
NA
NA
-
-
Preliminary
DS40300B-page 75
PIC16F62X
12.1.1
SAMPLING
The data on the RB1/RX/DT pin is sampled three times
by a majority detect circuit to determine if a high or a
low level is present at the RX pin. If bit BRGH
(TXSTA<2>) is clear (i.e., at the low baud rates), the
sampling is done on the seventh, eighth and ninth falling edges of a x16 clock (Figure 12-3). If bit BRGH is
set (i.e., at the high baud rates), the sampling is done
on the 3 clock edges preceding the second rising edge
after the first falling edge of a x4 clock (Figure 12-4 and
Figure 12-5).
FIGURE 12-1: RX PIN SAMPLING SCHEME. BRGH = 0
Start bit
RX
(RB1/RX/DT pin)
Bit0
Baud CLK for all but start bit
baud CLK
x16 CLK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
2
3
Samples
FIGURE 12-2: RX PIN SAMPLING SCHEME, BRGH = 1
RX pin
bit0
Start Bit
bit1
baud clk
First falling edge after RX pin goes low
Second rising edge
x4 clk
1
2
3
4
1
2
3
4
1
2
Q2, Q4 clk
Samples
DS40300B-page 76
Samples
Preliminary
Samples
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 12-3: RX PIN SAMPLING SCHEME, BRGH = 1
RX pin
Start Bit
bit0
Baud CLK for all but start bit
Baud CLK
First falling edge after RX pin goes low
Second rising edge
x4 CLK
1
2
3
4
Q2, Q4 CLK
Samples
FIGURE 12-4: RX PIN SAMPLING SCHEME, BRGH = 0 OR BRGH = 1
Start bit
RX
(RB1/RX/DT pin)
Bit0
Baud CLK for all but start bit
Baud CLK
x16 CLK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
2
3
Samples
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 77
PIC16F62X
12.2
USART Asynchronous Mode
state of enable bit TXIE and cannot be cleared in software. It will reset only when new data is loaded into the
TXREG register. While flag bit TXIF indicated the status of the TXREG register, another bit TRMT
(TXSTA<1>) shows the status of the TSR register. Status bit TRMT is a read only bit which is set when the
TSR register is empty. No interrupt logic is tied to this
bit, so the user has to poll this bit in order to determine
if the TSR register is empty.
In this mode, the USART uses standard nonreturn-tozero (NRZ) format (one start bit, eight or nine data bits
and one stop bit). The most common data format is
8-bits. An on-chip dedicated 8-bit baud rate generator
can be used to derive standard baud rate frequencies
from the oscillator. The USART transmits and receives
the LSb first. The USART’s transmitter and receiver are
functionally independent but use the same data format
and baud rate. The baud rate generator produces a
clock either x16 or x64 of the bit shift rate, depending
on bit BRGH (TXSTA<2>). Parity is not supported by
the hardware, but can be implemented in software (and
stored as the ninth data bit). Asynchronous mode is
stopped during SLEEP.
Note 1: The TSR register is not mapped in data
memory so it is not available to the user.
Note 2: Flag bit TXIF is set when enable bit TXEN
is set.
Transmission is enabled by setting enable bit TXEN
(TXSTA<5>). The actual transmission will not occur
until the TXREG register has been loaded with data
and the baud rate generator (BRG) has produced a
shift clock (Figure 12-5). The transmission can also be
started by first loading the TXREG register and then
setting enable bit TXEN. Normally when transmission
is first started, the TSR register is empty, so a transfer
to the TXREG register will result in an immediate transfer to TSR resulting in an empty TXREG. A back-toback transfer is thus possible (Figure 12-7). Clearing
enable bit TXEN during a transmission will cause the
transmission to be aborted and will reset the transmitter. As a result the RB2/TX/CK pin will revert to hiimpedance.
Asynchronous mode is selected by clearing bit SYNC
(TXSTA<4>).
The USART Asynchronous module consists of the following important elements:
•
•
•
•
Baud Rate Generator
Sampling Circuit
Asynchronous Transmitter
Asynchronous Receiver
12.2.1
USART ASYNCHRONOUS TRANSMITTER
The USART transmitter block diagram is shown in
Figure 12-5. The heart of the transmitter is the transmit
(serial) shift register (TSR). The shift register obtains its
data from the read/write transmit buffer, TXREG. The
TXREG register is loaded with data in software. The
TSR register is not loaded until the STOP bit has been
transmitted from the previous load. As soon as the
STOP bit is transmitted, the TSR is loaded with new
data from the TXREG register (if available). Once the
TXREG register transfers the data to the TSR register
(occurs in one TCY), the TXREG register is empty and
flag bit TXIF (PIR1<4>) is set. This interrupt can be
enabled/disabled by setting/clearing enable bit TXIE
( PIE1<4>). Flag bit TXIF will be set regardless of the
In order to select 9-bit transmission, transmit bit TX9
(TXSTA<6>) should be set and the ninth bit should be
written to TX9D (TXSTA<0>). The ninth bit must be
written before writing the 8-bit data to the TXREG register. This is because a data write to the TXREG register can result in an immediate transfer of the data to the
TSR register (if the TSR is empty). In such a case, an
incorrect ninth data bit maybe loaded in the TSR register.
FIGURE 12-5: USART TRANSMIT BLOCK DIAGRAM
Data Bus
TXIF
TXREG register
TXIE
8
MSb
LSb
• • •
(8)
Pin Buffer
and Control
0
TSR register
RB2/TX/CK pin
Interrupt
TXEN
Baud Rate CLK
TRMT
SPEN
SPBRG
Baud Rate Generator
TX9
TX9D
DS40300B-page 78
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
Steps to follow when setting up an Asynchronous
Transmission:
4.
1.
5.
Initialize the SPBRG register for the appropriate
baud rate. If a high speed baud rate is desired,
set bit BRGH. (Section 12.1)
Enable the asynchronous serial port by clearing
bit SYNC and setting bit SPEN.
If interrupts are desired, then set enable bit
TXIE.
2.
3.
If 9-bit transmission is desired, then set transmit
bit TX9.
Enable the transmission by setting bit TXEN,
which will also set bit TXIF.
If 9-bit transmission is selected, the ninth bit
should be loaded in bit TX9D.
Load data to the TXREG register (starts transmission).
6.
7.
FIGURE 12-6: ASYNCHRONOUS MASTER TRANSMISSION
Write to TXREG
Word 1
BRG output
(shift clock)
RB2/TX/CK (pin)
Start Bit
Bit 0
Bit 1
Bit 7/8
Stop Bit
WORD 1
TXIF bit
(Transmit buffer
reg. empty flag)
WORD 1
Transmit Shift Reg
TRMT bit
(Transmit shift
reg. empty flag)
FIGURE 12-7: ASYNCHRONOUS MASTER TRANSMISSION (BACK TO BACK)
Write to TXREG
RB2/TX/CK (pin)
Start Bit
TXIF bit
(interrupt reg. flag)
TRMT bit
(Transmit shift
reg. empty flag)
Word 2
Word 1
BRG output
(shift clock)
Bit 0
Bit 1
WORD 1
Bit 7/8
Stop Bit
Start Bit
Bit 0
WORD 2
WORD 1
Transmit Shift Reg.
WORD 2
Transmit Shift Reg.
Note: This timing diagram shows two consecutive transmissions.
TABLE 12-6:
REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Value on
all other
Resets
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
0000 -000
18h
RCSTA
SPEN
RX9
SREN
CREN
ADEN
FERR
OERR
RX9D
0000 -00x
0000 -00x
0000 0000
0000 0000
TMR1IE
0000 -000
0000 -000
TX9D
0000 -010
0000 -010
0000 0000
0000 0000
19h
TXREG USART Transmit Register
8Ch
PIE1
EEIE
CSRC
CMIE
TX9
RCIE
TXEN
98h
TXSTA
99h
SPBRG Baud Rate Generator Register
TXIE
SYNC
—
—
CCP1IE
BRGH
TMR2IE
TRMT
Legend: x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for Asynchronous Transmission.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 79
PIC16F62X
12.2.2
USART ASYNCHRONOUS RECEIVER
ered register, i.e. it is a two deep FIFO. It is possible for
two bytes of data to be received and transferred to the
RCREG FIFO and a third byte begin shifting to the RSR
register. On the detection of the STOP bit of the third
byte, if the RCREG register is still full then overrun error
bit OERR (RCSTA<1>) will be set. The word in the RSR
will be lost. The RCREG register can be read twice to
retrieve the two bytes in the FIFO. Overrun bit OERR
has to be cleared in software. This is done by resetting
the receive logic (CREN is cleared and then set). If bit
OERR is set, transfers from the RSR register to the
RCREG register are inhibited, so it is essential to clear
error bit OERR if it is set. Framing error bit FERR
(RCSTA<2>) is set if a stop bit is detected as clear. Bit
FERR and the 9th receive bit are buffered the same
way as the receive data. Reading the RCREG, will load
bits RX9D and FERR with new values, therefore it is
essential for the user to read the RCSTA register before
reading RCREG register in order not to lose the old
FERR and RX9D information.
The receiver block diagram is shown in Figure 12-8.
The data is received on the RB1/RX/DT pin and drives
the data recovery block. The data recovery block is
actually a high speed shifter operating at x16 times the
baud rate, whereas the main receive serial shifter operates at the bit rate or at FOSC.
Once Asynchronous mode is selected, reception is
enabled by setting bit CREN (RCSTA<4>).
The heart of the receiver is the receive (serial) shift register (RSR). After sampling the STOP bit, the received
data in the RSR is transferred to the RCREG register (if
it is empty). If the transfer is complete, flag bit RCIF
(PIR1<5>) is set. The actual interrupt can be enabled/
disabled by setting/clearing enable bit RCIE (PIE1<5>).
Flag bit RCIF is a read only bit which is cleared by the
hardware. It is cleared when the RCREG register has
been read and is empty. The RCREG is a double buff-
FIGURE 12-8: USART RECEIVE BLOCK DIAGRAM
x64 Baud Rate CLK
FERR
OERR
CREN
SPBRG
÷ 64
or
÷ 16
Baud Rate Generator
RSR register
MSb
Stop (8)
7
• • •
1
LSb
0 Start
RB1/RX/DT
Pin Buffer
and Control
Data
Recovery
RX9
8
SPEN
RX9
ADEN
Enable
Load of
RX9
ADEN
RSR<8>
Receive
Buffer
8
RX9D
RCREG register
RX9D
RCREG register
FIFO
8
Interrupt
RCIF
Data Bus
RCIE
DS40300B-page 80
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 12-9: ASYNCHRONOUS RECEPTION WITH ADDRESS DETECT
Start
bit
RC7/RX/DT (pin)
bit0
bit1
bit8
Stop
bit
Start
bit
bit0
bit8
Stop
bit
Rcv shift reg
Rcv buffer reg
Bit8 = 0, Data Byte
Bit8 = 1, Address Byte
Read Rcv
buffer reg
RCREG
WORD 1
RCREG
RCIF
(interrupt flag)
ADEN = 1
(address match
enable)
’1’
’1’
Note: This timing diagram shows a data byte followed by an address byte. The data byte is not read into the RCREG (receive buffer)
because ADEN = 1 and bit8 = 0.
FIGURE 12-10: ASYNCHRONOUS RECEPTION WITH ADDRESS BYTE FIRST
Start
bit
RC7/RX/DT (pin)
bit0
Rcv shift
reg
Rcv buffer reg
bit1
bit8
Bit8 = 1, Address Byte
Read Rcv
buffer reg
RCREG
Stop
bit
Start
bit
WORD 1
RCREG
bit0
bit8
Stop
bit
Bit8 = 0, Data Byte
RCIF
(interrupt flag)
ADEN = 1
(address match
enable)
’1’
’1’
Note: This timing diagram shows an address byte followed by an data byte. The data byte is not read into the RCREG (receive buffer)
because ADEN was not updated (still = 1) and bit8 = 0.
FIGURE 12-11: ASYNCHRONOUS RECEPTION WITH ADDRESS BYTE FIRST FOLLOWED BY VALID
DATA BYTE
RC7/RX/DT (pin)
Start
bit
bit0
Rcv shift
reg
Rcv buffer reg
Read Rcv
buffer reg
RCREG
bit1
bit8
Bit8 = 1, Address Byte
Stop
bit
Start
bit
WORD 1
RCREG
bit0
bit8
Bit8 = 0, Data Byte
Stop
bit
WORD 2
RCREG
RCIF
(interrupt flag)
ADEN
(address match
enable)
Note: This timing diagram shows an address byte followed by an data byte. The data byte is read into the RCREG (receive buffer)
because ADEN was updated after an address match, and was cleared to a ‘0’, so the contents of the receive shift register (RSR)
are read into the receive buffer regardless of the value of bit8.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 81
PIC16F62X
Steps to follow when setting up an Asynchronous
Reception:
1.
2.
3.
4.
5.
6.
Initialize the SPBRG register for the appropriate
baud rate. If a high speed baud rate is desired,
set bit BRGH. (Section 12.1).
Enable the asynchronous serial port by clearing
bit SYNC, and setting bit SPEN.
If interrupts are desired, then set enable bit
RCIE.
If 9-bit reception is desired, then set bit RX9.
Enable the reception by setting bit CREN.
TABLE 12-7:
Flag bit RCIF will be set when reception is complete and an interrupt will be generated if enable
bit RCIE was set.
Read the RCSTA register to get the ninth bit (if
enabled) and determine if any error occurred
during reception.
Read the 8-bit received data by reading the
RCREG register.
If any error occurred, clear the error by clearing
enable bit CREN.
7.
8.
9.
REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Value on
all other
Resets
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
0000 -000
18h
RCSTA
SPEN
RX9
SREN
CREN
ADEN
FERR
OERR
RX9D
0000 -00x
0000 -00x
1Ah
RCREG USART Receive Register
0000 0000
0000 0000
8Ch
PIE1
EEIE
CMIE
RCIE
TXIE
—
CCP1IE
TMR2IE
TMR1IE
0000 -000
0000 -000
98h
TXSTA
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D
0000 -010
0000 -010
99h
SPBRG
0000 0000
0000 0000
Baud Rate Generator Register
Legend: x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for Asynchronous Reception.
DS40300B-page 82
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
12.3
USART Function
12.3.1.1
The USART function is similar to that on the
PIC16C74B, which includes the BRGH = 1 fix.
12.3.1
USART 9-BIT RECEIVER WITH ADDRESS
DETECT
When the RX9 bit is set in the RCSTA register, 9-bits
are received and the ninth bit is placed in the RX9D bit
of the RCSTA register. The USART module has a special provision for multi-processor communication. Multiprocessor communication is enabled by setting the
ADEN bit (RCSTA<3>) along with the RX9 bit. The port
is now programmed such that when the last bit is
received, the contents of the receive shift register
(RSR) are transferred to the receive buffer, the ninth bit
of the RSR (RSR<8>) is transferred to RX9D, and the
receive interrupt is set if and only if RSR<8> = 1. This
feature can be used in a multi-processor system as follows:
A master processor intends to transmit a block of data
to one of many slaves. It must first send out an address
byte that identifies the target slave. An address byte is
identified by setting the ninth bit (RSR<8>) to a ’1’
(instead of a ’0’ for a data byte). If the ADEN and RX9
bits are set in the slave’s RCSTA register, enabling multiprocessor communication, all data bytes will be
ignored. However, if the ninth received bit is equal to a
‘1’, indicating that the received byte is an address, the
slave will be interrupted and the contents of the RSR
register will be transferred into the receive buffer. This
allows the slave to be interrupted only by addresses, so
that the slave can examine the received byte to see if it
is being addressed. The addressed slave will then
clear its ADEN bit and prepare to receive data bytes
from the master.
SETTING UP 9-BIT MODE WITH
ADDRESS DETECT
Steps to follow when setting up an Asynchronous or
Synchronous Reception with Address Detect Enabled:
1.
Initialize the SPBRG register for the appropriate
baud rate. If a high speed baud rate is desired,
set bit BRGH.
2. Enable asynchronous or synchronous communication by setting or clearing bit SYNC and setting bit SPEN.
3. If interrupts are desired, then set enable bit
RCIE.
4. Set bit RX9 to enable 9-bit reception.
5. Set ADEN to enable address detect.
6. Enable the reception by setting enable bit CREN
or SREN.
7. Flag bit RCIF will be set when reception is complete, and an interrupt will be generated if
enable bit RCIE was set.
8. Read the 8-bit received data by reading the
RCREG register to determine if the device is
being addressed.
9. If any error occurred, clear the error by clearing
enable bit CREN if it was already set.
10. If the device has been addressed (RSR<8> = 1
with address match enabled), clear the ADEN
and RCIF bits to allow data bytes and address
bytes to be read into the receive buffer and interrupt the CPU.
When ADEN is enabled (='1'), all data bytes are
ignored. Following the STOP bit, the data will not be
loaded into the receive buffer, and no interrupt will
occur. If another byte is shifted into the RSR register,
the previous data byte will be lost.
The ADEN bit will only take effect when the receiver is
configured in 9-bit mode (RX9 = '1'). When ADEN is
disabled (='0'), all data bytes are received and the 9th
bit can be used as the parity bit.
The receive block diagram is shown in Figure 12-8.
Reception is enabled by setting bit CREN (RCSTA<4>).
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 83
PIC16F62X
TABLE 12-1:
REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Addr
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Value on
all other
Resets
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
0000 -000
18h
RCSTA
SPEN
RX9
SREN
CREN
ADEN
FERR
OERR
RX9D
0000 -00x
0000 -00x
1Ah
RCREG
RX7
RX6
RX5
RX4
RX3
RX2
RX1
RX0
0000 0000
0000 0000
8Ch
PIE1
EEIE
CMIE
RCIE
TXIE
—
CCP1IE
TMR2IE
TMR1IE
0000 -000
0000 -000
98h
TXSTA
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D
0000 -010
0000 -010
99h
SPBRG
0000 0000
0000 0000
Baud Rate Generator Register
Legend: x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for Asynchronous Reception.
12.4
USART Synchronous Master Mode
In Synchronous Master mode, the data is transmitted in
a half-duplex manner, i.e. transmission and reception
do not occur at the same time. When transmitting data,
the reception is inhibited and vice versa. Synchronous
mode is entered by setting bit SYNC (TXSTA<4>). In
addition enable bit SPEN (RCSTA<7>) is set in order to
configure the RB2/TX/CK and RB1/RX/DT I/O pins to
CK (clock) and DT (data) lines respectively. The Master
mode indicates that the processor transmits the master
clock on the CK line. The Master mode is entered by
setting bit CSRC (TXSTA<7>).
12.4.1
USART SYNCHRONOUS MASTER
TRANSMISSION
The USART transmitter block diagram is shown in
Figure 12-5. The heart of the transmitter is the transmit
(serial) shift register (TSR). The shift register obtains its
data from the read/write transmit buffer register
TXREG. The TXREG register is loaded with data in
software. The TSR register is not loaded until the last
bit has been transmitted from the previous load. As
soon as the last bit is transmitted, the TSR is loaded
with new data from the TXREG (if available). Once the
TXREG register transfers the data to the TSR register
(occurs in one Tcycle), the TXREG is empty and interrupt bit, TXIF (PIR1<4>) is set. The interrupt can be
enabled/disabled by setting/clearing enable bit TXIE
(PIE1<4>). Flag bit TXIF will be set regardless of the
state of enable bit TXIE and cannot be cleared in software. It will reset only when new data is loaded into the
TXREG register. While flag bit TXIF indicates the status
of the TXREG register, another bit TRMT (TXSTA<1>)
shows the status of the TSR register. TRMT is a read
only bit which is set when the TSR is empty. No interrupt logic is tied to this bit, so the user has to poll this
bit in order to determine if the TSR register is empty.
The TSR is not mapped in data memory so it is not
available to the user.
ble around the falling edge of the synchronous clock
(Figure 12-12). The transmission can also be started
by first loading the TXREG register and then setting bit
TXEN (Figure 12-13). This is advantageous when slow
baud rates are selected, since the BRG is kept in reset
when bits TXEN, CREN, and SREN are clear. Setting
enable bit TXEN will start the BRG, creating a shift
clock immediately. Normally when transmission is first
started, the TSR register is empty, so a transfer to the
TXREG register will result in an immediate transfer to
TSR resulting in an empty TXREG. Back-to-back transfers are possible.
Clearing enable bit TXEN, during a transmission, will
cause the transmission to be aborted and will reset the
transmitter. The DT and CK pins will revert to hi-impedance. If either bit CREN or bit SREN is set, during a
transmission, the transmission is aborted and the DT
pin reverts to a hi-impedance state (for a reception).
The CK pin will remain an output if bit CSRC is set
(internal clock). The transmitter logic however is not
reset although it is disconnected from the pins. In order
to reset the transmitter, the user has to clear bit TXEN.
If bit SREN is set (to interrupt an on-going transmission
and receive a single word), then after the single word is
received, bit SREN will be cleared and the serial port
will revert back to transmitting since bit TXEN is still set.
The DT line will immediately switch from hi-impedance
receive mode to transmit and start driving. To avoid
this, bit TXEN should be cleared.
In order to select 9-bit transmission, the TX9
(TXSTA<6>) bit should be set and the ninth bit should
be written to bit TX9D (TXSTA<0>). The ninth bit must
be written before writing the 8-bit data to the TXREG
register. This is because a data write to the TXREG can
result in an immediate transfer of the data to the TSR
register (if the TSR is empty). If the TSR was empty and
the TXREG was written before writing the “new” TX9D,
the “present” value of bit TX9D is loaded.
Transmission is enabled by setting enable bit TXEN
(TXSTA<5>). The actual transmission will not occur
until the TXREG register has been loaded with data.
The first data bit will be shifted out on the next available
rising edge of the clock on the CK line. Data out is sta-
DS40300B-page 84
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
4.
5.
6.
Steps to follow when setting up a Synchronous Master
Transmission:
1.
Initialize the SPBRG register for the appropriate
baud rate (Section 12.1).
Enable the synchronous master serial port by
setting bits SYNC, SPEN, and CSRC.
If interrupts are desired, then set enable bit
TXIE.
2.
3.
TABLE 12-2:
If 9-bit transmission is desired, then set bit TX9.
Enable the transmission by setting bit TXEN.
If 9-bit transmission is selected, the ninth bit
should be loaded in bit TX9D.
Start transmission by loading data to the
TXREG register.
7.
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Value on
POR
Value on all
other Resets
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
0000 -000
RX9D
0000 -00x
0000 -00x
0000 0000
0000 0000
0000 -000
18h
RCSTA
19h
TXREG
SPEN
RX9
SREN
CREN
ADEN
FERR
OERR
USART Transmit Register
8Ch
PIE1
EEIE
CMIE
RCIE
TXIE
—
CCP1IE
TMR2IE
TMR1IE
0000 -000
98h
TXSTA
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D
0000 -010
0000 -010
0000 0000
0000 0000
99h
SPBRG
Baud Rate Generator Register
Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Master Transmission.
FIGURE 12-12: SYNCHRONOUS TRANSMISSION
Q1Q2 Q3Q4 Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2 Q3Q4
RB1/RX/DT pin
Bit 0
Bit 1
Q3Q4 Q1Q2 Q3Q4 Q1Q2 Q3Q4 Q1Q2 Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4
Bit 2
Bit 7
Bit 0
WORD 1
Bit 1
WORD 2
Bit 7
RB2/TX/CK pin
Write to
TXREG reg
Write word1
Write word2
TXIF bit
(Interrupt flag)
TRMT
TRMT bit
TXEN bit
’1’
’1’
Note: Sync master mode; SPBRG = ’0’. Continuous transmission of two 8-bit words
FIGURE 12-13: SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
RB1/RX/DT pin
bit0
bit1
bit2
bit6
bit7
RB2/TX/CK pin
Write to
TXREG reg
TXIF bit
TRMT bit
TXEN bit
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 85
PIC16F62X
12.4.2
USART SYNCHRONOUS MASTER
RECEPTION
receive bit is buffered the same way as the receive
data. Reading the RCREG register, will load bit RX9D
with a new value, therefore it is essential for the user to
read the RCSTA register before reading RCREG in
order not to lose the old RX9D information.
Once Synchronous mode is selected, reception is
enabled by setting either enable bit SREN (RCSTA<5>)
or enable bit CREN (RCSTA<4>). Data is sampled on
the RB1/RX/DT pin on the falling edge of the clock. If
enable bit SREN is set, then only a single word is
received. If enable bit CREN is set, the reception is
continuous until CREN is cleared. If both bits are set
then CREN takes precedence. After clocking the last
bit, the received data in the Receive Shift Register
(RSR) is transferred to the RCREG register (if it is
empty). When the transfer is complete, interrupt flag bit
RCIF (PIR1<5>) is set. The actual interrupt can be
enabled/disabled by setting/clearing enable bit RCIE
(PIE1<5>). Flag bit RCIF is a read only bit which is
reset by the hardware. In this case it is reset when the
RCREG register has been read and is empty. The
RCREG is a double buffered register, i.e. it is a two
deep FIFO. It is possible for two bytes of data to be
received and transferred to the RCREG FIFO and a
third byte to begin shifting into the RSR register. On the
clocking of the last bit of the third byte, if the RCREG
register is still full then overrun error bit OERR
(RCSTA<1>) is set. The word in the RSR will be lost.
The RCREG register can be read twice to retrieve the
two bytes in the FIFO. Bit OERR has to be cleared in
software (by clearing bit CREN). If bit OERR is set,
transfers from the RSR to the RCREG are inhibited, so
it is essential to clear bit OERR if it is set. The 9th
TABLE 12-3:
Steps to follow when setting up a Synchronous Master
Reception:
1.
Initialize the SPBRG register for the appropriate
baud rate. (Section 12.1)
2. Enable the synchronous master serial port by
setting bits SYNC, SPEN, and CSRC.
3. Ensure bits CREN and SREN are clear.
4. If interrupts are desired, then set enable bit
RCIE.
5. If 9-bit reception is desired, then set bit RX9.
6. If a single reception is required, set bit SREN.
For continuous reception set bit CREN.
7. Interrupt flag bit RCIF will be set when reception
is complete and an interrupt will be generated if
enable bit RCIE was set.
8. Read the RCSTA register to get the ninth bit (if
enabled) and determine if any error occurred
during reception.
9. Read the 8-bit received data by reading the
RCREG register.
10. If any error occurred, clear the error by clearing
bit CREN.
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR
Value on all
other Resets
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
0000 -000
RX9D
0000 -00x
0000 -00x
0000 0000
0000 0000
-000 -000
18h
RCSTA
1Ah
RCREG
SPEN
RX9
SREN
CREN
ADEN
FERR
OERR
USART Receive Register
8Ch
PIE1
EEPIE
CMIE
RCIE
TXIE
—
CCP1IE
TMR2IE
TMR1IE
-000 0000
98h
TXSTA
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D
0000 -010
0000 -010
0000 0000
0000 0000
99h
SPBRG
Baud Rate Generator Register
Legend: x = unknown, - = unimplemented read as '0'. Shaded cells are not used for Synchronous Master Reception.
DS40300B-page 86
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 12-14: SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RB1/RX/DT pin
bit0
bit1
bit2
bit3
bit4
bit5
bit6
bit7
RB2/TX/CK pin
Write to
bit SREN
SREN bit
CREN bit ’0’
’0’
RCIF bit
(interrupt)
Read
RXREG
Note: Timing diagram demonstrates SYNC master mode with bit SREN = ’1’ and bit BRG = ’0’.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 87
PIC16F62X
12.5
USART Synchronous Slave Mode
12.5.2
Synchronous slave mode differs from the Master mode
in the fact that the shift clock is supplied externally at
the RB2/TX/CK pin (instead of being supplied internally
in master mode). This allows the device to transfer or
receive data while in SLEEP mode. Slave mode is
entered by clearing bit CSRC (TXSTA<7>).
12.5.1
USART SYNCHRONOUS SLAVE
TRANSMIT
The operation of the synchronous master and slave
modes are identical except in the case of the SLEEP
mode.
If two words are written to the TXREG and then the
SLEEP instruction is executed, the following will occur:
a)
b)
c)
d)
e)
The first word will immediately transfer to the
TSR register and transmit.
The second word will remain in TXREG register.
Flag bit TXIF will not be set.
When the first word has been shifted out of TSR,
the TXREG register will transfer the second
word to the TSR and flag bit TXIF will now be
set.
If enable bit TXIE is set, the interrupt will wake
the chip from SLEEP and if the global interrupt
is enabled, the program will branch to the interrupt vector (0004h).
Steps to follow when setting up a Synchronous Slave
Transmission:
1.
2.
3.
4.
5.
6.
7.
Enable the synchronous slave serial port by setting bits SYNC and SPEN and clearing bit
CSRC.
Clear bits CREN and SREN.
If interrupts are desired, then set enable bit
TXIE.
If 9-bit transmission is desired, then set bit TX9.
Enable the transmission by setting enable bit
TXEN.
If 9-bit transmission is selected, the ninth bit
should be loaded in bit TX9D.
Start transmission by loading data to the
TXREG register.
DS40300B-page 88
USART SYNCHRONOUS SLAVE
RECEPTION
The operation of the synchronous master and slave
modes is identical except in the case of the SLEEP
mode. Also, bit SREN is a don’t care in slave mode.
If receive is enabled, by setting bit CREN, prior to the
SLEEP instruction, then a word may be received during
SLEEP. On completely receiving the word, the RSR
register will transfer the data to the RCREG register
and if enable bit RCIE bit is set, the interrupt generated
will wake the chip from SLEEP. If the global interrupt is
enabled, the program will branch to the interrupt vector
(0004h).
Steps to follow when setting up a Synchronous Slave
Reception:
1.
2.
3.
4.
5.
6.
7.
8.
Preliminary
Enable the synchronous master serial port by
setting bits SYNC and SPEN and clearing bit
CSRC.
If interrupts are desired, then set enable bit
RCIE.
If 9-bit reception is desired, then set bit RX9.
To enable reception, set enable bit CREN.
Flag bit RCIF will be set when reception is complete and an interrupt will be generated, if
enable bit RCIE was set.
Read the RCSTA register to get the ninth bit (if
enabled) and determine if any error occurred
during reception.
Read the 8-bit received data by reading the
RCREG register.
If any error occurred, clear the error by clearing
bit CREN.
 1999 Microchip Technology Inc.
PIC16F62X
TABLE 12-4:
REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Value on all
other Resets
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
0000 -000
18h
RCSTA
SPEN
RX9
SREN
CREN
ADEN
FERR
OERR
RX9D
19h
TXREG
8Ch
PIE1
98h
TXSTA
99h
SPBRG
0000 -00x
0000 -00x
0000 0000
0000 0000
TMR1IE
0000 -000
0000 -000
TX9D
0000 -010
0000 -010
0000 0000
0000 0000
USART Transmit Register
EEIE
CSRC
CMIE
TX9
RCIE
TXEN
TXIE
SYNC
—
—
CCP1IE
BRGH
TMR2IE
TRMT
Baud Rate Generator Register
Legend: x = unknown, - = unimplemented read as '0'. Shaded cells are not used for Synchronous Slave Transmission.
TABLE 12-5:
REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Value on all
other Resets
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
0000 -000
RX9D
0000 -00x
0000 -00x
0000 0000
0000 0000
0000 -000
18h
RCSTA
1Ah
RCREG
SPEN
RX9
SREN
CREN
ADEN
FERR
OERR
USART Receive Register
8Ch
PIE1
EEIE
CMIE
RCIE
TXIE
—
CCP1IE
TMR2IE
TMR1IE
0000 -000
98h
TXSTA
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D
0000 -010
0000 -010
0000 0000
0000 0000
99h
SPBRG
Baud Rate Generator Register
Legend: x = unknown, - = unimplemented read as '0'. Shaded cells are not used for Synchronous Slave Reception.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 89
PIC16F62X
NOTES:
DS40300B-page 90
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
13.0
DATA EEPROM MEMORY
The EEPROM data memory is readable and writable
during normal operation (full VDD range). This memory
is not directly mapped in the register file space. Instead
it is indirectly addressed through the Special Function
Registers. There are four SFRs used to read and write
this memory. These registers are:
The EEPROM data memory allows byte read and write.
A byte write automatically erases the location and
writes the new data (erase before write). The EEPROM
data memory is rated for high erase/write cycles. The
write time is controlled by an on-chip timer. The writetime will vary with voltage and temperature as well as
from chip to chip. Please refer to AC specifications for
exact limits.
•
•
•
•
EECON1
EECON2 (Not a physically implemented register)
EEDATA
EEADR
When the device is code protected, the CPU may
continue to read and write the data EEPROM memory.
The device programmer can no longer access
this memory.
EEDATA holds the 8-bit data for read/write, and EEADR
holds the address of the EEPROM location being
accessed. PIC16F62X devices have 128 bytes of data
EEPROM with an address range from 0h to 7Fh.
Additional information on the Data EEPROM is available in the PICmicro™ Mid-Range Reference Manual,
(DS33023).
REGISTER 13-1: EEADR REGISTER (ADDRESS 9Bh)
U
—
bit7
R/W
EADR6
R/W
EADR5
R/W
EADR4
R/W
EADR3
R/W
EADR2
R/W
EADR1
R/W
EADR0
bit0
R = Readable bit
W = Writable bit
S = Settable bit
U = Unimplemented bit, read
as ‘0’
-n = Value at POR reset
bit 7
Unimplemented Address: Must be set to '0'
bit 6:0
EEADR: Specifies one of 128 locations for EEPROM Read/Write Operation
13.1
EEADR
The EEADR register can address up to a maximum of
256 bytes of data EEPROM. Only the first 128 bytes of
data EEPROM are implemented and only seven of the
eight bits in the register (EEADR<6:0>) are required.
The upper bit is address decoded. This means that
this bit should always be ’0’ to ensure that the address
is in the 128 byte memory space.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 91
PIC16F62X
13.2
EECON1 AND EECON2 REGISTERS
The WREN bit, when set, will allow a write operation.
On power-up, the WREN bit is clear. The WRERR bit
is set when a write operation is interrupted by a MCLR
reset or a WDT time-out reset during normal operation. In these situations, following reset, the user can
check the WRERR bit and rewrite the location. The
data and address will be unchanged in the EEDATA
and EEADR registers.
EECON1 is the control register with five low order bits
physically implemented. The upper-three bits are nonexistent and read as ’0’s.
Control bits RD and WR initiate read and write,
respectively. These bits cannot be cleared, only set, in
software. They are cleared in hardware at completion
of the read or write operation. The inability to clear the
WR bit in software prevents the accidental, premature
termination of a write operation.
Interrupt flag bit EEIF in the PIR1 register is set when
write is complete. This bit must be cleared in software.
EECON2 is not a physical register. Reading EECON2
will read all ’0’s. The EECON2 register is used
exclusively in the Data EEPROM write sequence.
REGISTER 13-2: EECON1 REGISTER (ADDRESS 9Ch) DEVICES
U
U
U
U
R/W-x
R/W-0
R/S-0
R/S-x
—
—
—
—
WRERR
WREN
WR
RD
bit7
bit0
R = Readable bit
W = Writable bit
S = Settable bit
U = Unimplemented bit,
read as ‘0’
-n = Value at POR reset
bit 7:4
Unimplemented: Read as '0'
bit 3
WRERR: EEPROM Error Flag bit
1 = A write operation is prematurely terminated
(any MCLR reset, any WDT reset during normal operation or BOD detect)
0 = The write operation completed
bit 2
WREN: EEPROM Write Enable bit
1 = Allows write cycles
0 = Inhibits write to the data EEPROM
bit 1
WR: Write Control bit
1 = initiates a write cycle. (The bit is cleared by hardware once write is complete. The WR bit can only
be set (not cleared) in software.
0 = Write cycle to the data EEPROM is complete
bit 0
RD: Read Control bit
1 = Initiates an EEPROM read (read takes one cycle. RD is cleared in hardware. The RD bit can only be
set (not cleared) in software).
0 = Does not initiate an EEPROM read
DS40300B-page 92
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
13.3
READING THE EEPROM DATA
MEMORY
To read a data memory location, the user must write
the address to the EEADR register and then set control bit RD (EECON1<0>). The data is available, in the
very next cycle, in the EEDATA register; therefore it
can be read in the next instruction. EEDATA will hold
this value until another read or until it is written to by
the user (during a write operation).
EXAMPLE 13-1: DATA EEPROM READ
BCF
MOVLW
MOVWF
BSF
BSF
BCF
MOVF
13.4
STATUS, RP0
CONFIG_ADDR
EEADR
STATUS, RP0
EECON1, RD
STATUS, RP0
EEDATA, W
;
;
;
;
;
;
;
Bank 0
Address to read
Bank 1
EE Read
Bank 0
W = EEDATA
13.5
EXAMPLE 13-2: DATA EEPROM WRITE
BSF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
STATUS, RP0
EECON1, WREN
INTCON, GIE
55h
EECON2
AAh
EECON2
EECON1,WR
BSF
INTCON, GIE
;
;
;
;
;
;
;
;
;
;
Bank 1
Enable write
Disable INTs.
Write 55h
Write AAh
Set WR bit
begin write
Enable INTs.
EXAMPLE 13-3: WRITE VERIFY
BCF
:
:
MOVF
BSF
BSF
Additionally, the WREN bit in EECON1 must be set to
enable write. This mechanism prevents accidental
writes to data EEPROM due to errant (unexpected)
code execution (i.e., lost programs). The user should
keep the WREN bit clear at all times, except when
updating EEPROM. The WREN bit is not cleared
by hardware
STATUS, RP0 ;
;
;
EEDATA, W
;
STATUS, RP0 ;
EECON1, RD ;
;
STATUS, RP0 ;
Bank 0
Any code can go here
Must be in Bank 0
Bank 1 READ
YES, Read the
value written
Bank 0
BCF
;
; Is the value written (in W reg) and
; read (in EEDATA) the same?
;
SUBWF EEDATA, W
;
BTFSS STATUS, Z
; Is difference 0?
GOTO WRITE_ERR
; NO, Write error
:
; YES, Good write
:
; Continue program
13.6
The write will not initiate if the above sequence is not
exactly followed (write 55h to EECON2, write AAh to
EECON2, then set WR bit) for each byte. We strongly
recommend that interrupts be disabled during this
code segment. A cycle count is executed during the
required sequence. Any number what is not equal to
the required cycles to execute the required sequence
will cause the data not to be written into the EEPROM.
WRITE VERIFY
Depending on the application, good programming
practice may dictate that the value written to the Data
EEPROM should be verified (Example 13-3) to the
desired value to be written. This should be used in
applications where an EEPROM bit will be stressed
near the specification limit.
WRITING TO THE EEPROM DATA
MEMORY
To write an EEPROM data location, the user must first
write the address to the EEADR register and the data
to the EEDATA register. Then the user must follow a
specific sequence to initiate the write for each byte.
Required
Sequence
At the completion of the write cycle, the WR bit is
cleared in hardware and the EE Write Complete
Interrupt Flag bit (EEIF) is set. The user can either
enable this interrupt or poll this bit. The EEIF bit in the
PIR1 registers must be cleared by software.
PROTECTION AGAINST SPURIOUS
WRITE
There are conditions when the device may not want to
write to the data EEPROM memory. To protect against
spurious EEPROM writes, various mechanisms have
been built in. On power-up, WREN is cleared. Also,
the Power-up Timer (72 ms duration) prevents
EEPROM write.
The write initiate sequence and the WREN bit together
help prevent an accidental write during brown-out,
power glitch, or software malfunction.
13.7
DATA EEPROM OPERATION DURING
CODE PROTECT
When the device is code protected, the CPU is able to
read and write unscrambled data to the Data
EEPROM.
After a write sequence has been initiated, clearing the
WREN bit will not affect this write cycle. The WR bit
will be inhibited from being set unless the WREN bit is
set.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 93
PIC16F62X
TABLE 13-1
Address
REGISTERS/BITS ASSOCIATED WITH DATA EEPROM
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
Power-on
Reset
Value on all
other resets
9Ah
EEDATA
EEPROM data register
xxxx xxxx
uuuu uuuu
9Bh
EEADR
9Ch
EECON1
EEPROM address register
—
—
—
xxxx xxxx
---- x000
uuuu uuuu
---- q000
9Dh
EECON2(1)
EEPROM control register 2
---- ----
---- ----
—
WRERR
WREN
WR
RD
Legend: x = unknown, u = unchanged, - = unimplemented read as ’0’, q = value depends upon condition. Shaded cells are not used
by data EEPROM.
Note 1: EECON2 is not a physical register
DS40300B-page 94
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
14.0
SPECIAL FEATURES OF THE
CPU
Special circuits to deal with the needs of real time applications are what sets a microcontroller apart from other
processors. The PIC16F62X family has a host of such
features intended to maximize system reliability, minimize cost through elimination of external components,
provide power saving operating modes and offer code
protection.
These are:
1.
2.
3.
4.
5.
6.
7.
8.
OSC selection
Reset
Power-on Reset (POR)
Power-up Timer (PWRT)
Oscillator Start-Up Timer (OST)
Brown-out Reset (BOD)
Interrupts
Watchdog Timer (WDT)
SLEEP
Code protection
ID Locations
In-circuit serial programming
 1999 Microchip Technology Inc.
The PIC16F62X has a Watchdog Timer which is
controlled by configuration bits. It runs off its own RC
oscillator for added reliability. There are two timers that
offer necessary delays on power-up. One is the
Oscillator Start-up Timer (OST), intended to keep the
chip in reset until the crystal oscillator is stable. The
other is the Power-up Timer (PWRT), which provides a
fixed delay of 72 ms (nominal) on power-up only,
designed to keep the part in reset while the power
supply stabilizes. There is also circuitry to reset the
device if a brown-out occurs which provides at least a
72 ms reset. With these three functions on-chip, most
applications need no external reset circuitry.
The SLEEP mode is designed to offer a very low
current power-down mode. The user can wake-up from
SLEEP through external reset, Watchdog Timer
wake-up or through an interrupt. Several oscillator
options are also made available to allow the part to fit
the application. The ER oscillator option saves system
cost while the LP crystal option saves power. A set of
configuration bits are used to select various options.
Preliminary
DS40300B-page 95
PIC16F62X
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.
The user will note that address 2007h is beyond
the user program memory space. In fact, it belongs
to the special configuration memory space (2000h
– 3FFFh), which can be accessed only during programming.
FIGURE 14-1: CONFIGURATION WORD
CP1
CP0
CP1
CP0
-
CPD
LVP
BODEN
MCLRE
FOSC2
PWRTE
WDTE
bit13
F0SC1
F0SC0
bit0
Register:CONFIG
Address2007h
bit 13-10:CP1:CP0: Code Protection bits (2)
Code protection for 2K program memory
11 = Program memory code protection off
10 = 0400h-07FFh code protected
01 = 0200h-07FFh code protected
00 = 0000h-07FFhcode protected
Code protection for 1K program memory
11 = Program memory code protection off
10 = Program memory code protection off
01 = 0200h-03FFh code protected
00 = 0000h-03FFh code protected
bit 8:
CPD: Data Code Protection bit(3)
1 = Data memory code protection off
0 = Data memory code protected
bit 7:
LVP: Low Voltage Programming Enable
1 = RB4/PGM pin has PGM function, low voltage programming enabled
0 = RB4/PGM is digital I/O, HV on MCLR must be used for programming
bit 6:
BODEN: Brown-out Detect Enable bit (1)
1 = BOD enabled
0 = BOD disabled
bit 5:
MCLRE: RA5/MCLR pin function select
1 = RA5/MCLR pin function is MCLR
0 = RA5/MCLR pin function is digital I/O, MCLR internally tied to VDD
bit 3:
PWRTE: Power-up Timer Enable bit (1)
1 = PWRT disabled
0 = PWRT enabled
bit 2:
WDTE: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
bit 4,1-0: FOSC2:FOSC0: Oscillator Selection bits(4)
111 = ER oscillator: CLKOUT function on RA6/OSC2/CLKOUT pin, Resistor on RA7/OSC1/CLKIN
110 = ER oscillator: I/O function on RA6/OSC2/CLKOUT pin, Resistor on RA7/OSC1/CLKIN
101 = INTRC oscillator: CLKOUT function on RA6/OSC2/CLKOUT pin, I/O function on RA7/OSC1/CLKIN
100 = INTRC oscillator: I/O function on RA6/OSC2/CLKOUT pin, I/O function on RA7/OSC1/CLKIN
011 = EC: I/O function on RA6/OSC2/CLKOUT pin, CLKIN on RA7/OSC1/CLKIN
010 = HS oscillator: High speed crystal/resonator on RA6/OSC2/CLKOUT and RA7/OSC1/CLKIN
001 = XT oscillator: Crystal/resonator on RA6/OSC2/CLKOUT and RA7/OSC1/CLKIN
000 = LP oscillator: Low power crystal on RA6/OSC2/CLKOUT and RA7/OSC1/CLKIN
Note 1: Enabling Brown-out Reset automatically enables Power-up Timer (PWRT) regardless of the value of bit PWRTE. Ensure the
Power-up Timer is enabled anytime Brown-out Reset is enabled.
2: All of the CP1:CP0 pairs have to be given the same value to enable the code protection scheme listed.
3: The entire data EEPROM will be erased when the code protection is turned off.
4: When MCLR is asserted in INTRC or ER mode, the internal clock oscillator is disabled.
DS40300B-page 96
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
14.2
Oscillator Configurations
14.2.1
OSCILLATOR TYPES
TABLE 14-1:
The PIC16F62X can be operated in eight different
oscillator options. The user can program three
configuration bits (FOSC2 thru FOSC0) to select one of
these eight modes:
•
•
•
•
•
•
LP
XT
HS
ER
INTRC
EC
14.2.2
Low Power Crystal
Crystal/Resonator
High Speed Crystal/Resonator
External Resistor (2 modes)
Internal Resistor/Capacitor (2 modes)
External Clock In
CRYSTAL OSCILLATOR / CERAMIC
RESONATORS
FIGURE 14-2: CRYSTAL OPERATION
(OR CERAMIC RESONATOR)
(HS, XT OR LP OSC
CONFIGURATION)
OSC1
To internal logic
C1
XTAL
Ranges Characterized:
Mode
Freq
OSC1(C1)
OSC2(C2)
XT
455 kHz
2.0 MHz
4.0 MHz
22 - 100 pF
15 - 68 pF
15 - 68 pF
22 - 100 pF
15 - 68 pF
15 - 68 pF
HS
8.0 MHz
16.0 MHz
10 - 68 pF
10 - 22 pF
10 - 68 pF
10 - 22 pF
Higher capacitance increases the stability of the oscillator
but also increases the start-up time. These values are for
design guidance only. Since each resonator has its own
characteristics, the user should consult the resonator manufacturer for appropriate values of external components.
TABLE 14-2:
In XT, LP or HS modes a crystal or ceramic resonator
is connected to the OSC1 and OSC2 pins to establish
oscillation (Figure 14-2). The PIC16F62X oscillator
design requires the use of a parallel cut crystal. Use of
a series cut crystal may give a frequency out of the
crystal manufacturers specifications. When in XT, LP or
HS modes, the device can have an external clock
source to drive the OSC1 pin (Figure 14-3).
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
Mode
Freq
OSC1(C1)
OSC2(C2)
LP
32 kHz
200 kHz
68 - 100 pF
15 - 30 pF
68 - 100 pF
15 - 30 pF
XT
100 kHz
2 MHz
4 MHz
68 - 150 pF
15 - 30 pF
15 - 30 pF
150 - 200 pF
15 - 30 pF
15 - 30 pF
HS
8 MHz
10 MHz
20 MHz
15 - 30 pF
15 - 30 pF
15 - 30 pF
15 - 30 pF
15 - 30 pF
15 - 30 pF
Higher capacitance increases the stability of the oscillator
but also increases the start-up time. These values are for
design guidance only. Rs may be required in HS mode as
well as XT mode to avoid overdriving crystals with low drive
level specification. Since each crystal has its own
characteristics, the user should consult the crystal manufacturer for appropriate values of external components.
SLEEP
RF
OSC2
RS
C2
see Note
PIC16F62X
See Table 14-1 and Table 14-2 for recommended
values of C1 and C2.
Note:
A series resistor may be required for
AT strip cut crystals.
FIGURE 14-3: EXTERNAL CLOCK INPUT
OPERATION (HS, XT OR LP
OSC CONFIGURATION)
Clock from
ext. system
OSC1
Open
OSC2
PIC16F62X
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 97
PIC16F62X
14.2.3
EXTERNAL CRYSTAL OSCILLATOR
CIRCUIT
14.2.4
Either a prepackaged oscillator can be used or a simple
oscillator circuit with TTL gates can be built.
Prepackaged oscillators provide a wide operating
range and better stability. A well-designed crystal
oscillator will provide good performance with TTL
gates. Two types of crystal oscillator circuits can be
used; one with series resonance, or one with parallel
resonance.
Figure 14-4 shows implementation of a parallel resonant oscillator circuit. The circuit is designed to use the
fundamental frequency of the crystal. The 74AS04
inverter performs the 180° phase shift that a parallel
oscillator requires. The 4.7 kΩ resistor provides the
negative feedback for stability. The 10 kΩ
potentiometers bias the 74AS04 in the linear region.
This could be used for external oscillator designs.
FIGURE 14-4: EXTERNAL PARALLEL
RESONANT CRYSTAL
OSCILLATOR CIRCUIT
To other
Devices
10k
74AS04
PIC16F62X
CLKIN
74AS04
10k
XTAL
10k
20 pF
For applications where a clock is already available elsewhere, users may directly drive the PIC16F62X provided that this external clock source meets the AC/DC
timing requirements listed in Section 17.4. Figure 14-6
below shows how an external clock circuit should be
configured.
FIGURE 14-6: EXTERNAL CLOCK INPUT
OPERATION (HS, XT OR LP
OSC CONFIGURATION)
Clock from
ext. system
20 pF
Figure 14-5 shows a series resonant oscillator circuit.
This circuit is also designed to use the fundamental
frequency of the crystal. The inverter performs a 180°
phase shift in a series resonant oscillator circuit. The
330 kΩ resistors provide the negative feedback to bias
the inverters in their linear region.
PIC16F62X
330 kΩ
74AS04
74AS04
To other
Devices
14.2.5
XTAL
DS40300B-page 98
ER OSCILLATOR
Figure 14-7 shows how the controlling resistor is connected to the PIC16F62X. For Rext values below 38k,
the oscillator operation may become unstable, or stop
completely. For very high Rext values (e.g. 1M), the
oscillator becomes sensitive to noise, humidity and
leakage. Thus, we recommend keeping Rext between
38k and 1M.
FIGURE 14-7: EXTERNAL RESISTOR
RA7/OSC1/CLKIN
RA6/OSC2/CLKOUT
PIC16F62X
74AS04
CLKIN
0.1 µF
OSC2/RA6
RA6
FIGURE 14-5: EXTERNAL SERIES
RESONANT CRYSTAL
OSCILLATOR CIRCUIT
330 kΩ
OSC1/RA7
For timing insensitive applications, the ER (External
Resistor) clock mode offers additional cost savings.
Only one external component, a resistor to VSS, is
needed to set the operating frequency of the internal
oscillator. The resistor draws a DC bias current which
controls the oscillation frequency. In addition to the
resistance value, the oscillator frequency will vary from
unit to unit, and as a function of supply voltage and temperature. Since the controlling parameter is a DC current and not a capacitance, the particular package type
and lead frame will not have a significant effect on the
resultant frequency.
+5V
4.7k
EXTERNAL CLOCK IN
The Electrical Specification section shows the relationship between the resistance value and the operating
frequency as well as frequency variations due to operating temperature for given R and VDD values.
The ER oscillator mode has two options that control the
unused OSC2 pin. The first allows it to be used as a
general purpose I/O port. The other configures the pin
as an output providing the Fosc signal (internal clock
divided by 4) for test or external synchronization purposes.
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
14.2.6
INTERNAL 4 MHZ OSCILLATOR
14.4
The internal RC oscillator provides a fixed 4 MHz (nominal) system clock at Vdd = 5V and 25°C, see “Electrical
Specifications” section for information on variation over
voltage and temperature.
14.2.7
CLKOUT
The PIC16F62X 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.
14.3
Special Feature: Dual Speed
Oscillator Modes
A software programmable dual speed oscillator mode
is provided when the PIC16F62X is configured in either
ER or INTRC oscillator modes. This feature allows
users to dynamically toggle the oscillator speed
between 4MHz and 37kHz. In ER mode, the 4MHz setting will vary depending on the size of the external
resistor. Also in ER mode, the 37kHz operation is fixed
and does not vary with resistor size. Applications that
require low current power savings, but cannot tolerate
putting the part into sleep, may use this mode.
The OSCF bit in the PCON register is used to control
dual speed mode. See Section 4.2.2.6, Figure 4-9.
 1999 Microchip Technology Inc.
Reset
The PIC16F62X differentiates between various kinds
of reset:
a)
b)
c)
d)
e)
f)
Power-on reset (POR)
MCLR reset during normal operation
MCLR reset during SLEEP
WDT reset (normal operation)
WDT wake-up (SLEEP)
Brown-out Detect (BOD)
Some registers are not affected in any reset condition;
their status is unknown on POR and unchanged in any
other reset. Most other registers are reset to a “reset
state” on Power-on reset, MCLR reset, WDT reset and
MCLR reset during SLEEP. They are not affected by a
WDT wake-up, since this is viewed as the resumption
of normal operation. TO and PD bits are set or cleared
differently in different reset situations as indicated in
Table 14-4. These bits are used in software to determine the nature of the reset. See Table 14-7 for a full
description of reset states of all registers.
A simplified block diagram of the on-chip reset circuit is
shown in Figure 14-8.
The MCLR reset path has a noise filter to detect and
ignore small pulses. See Table 12-6 for pulse width
specification.
Preliminary
DS40300B-page 99
PIC16F62X
FIGURE 14-8: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
External
Reset
MCLR/
VPP Pin
WDT
Module
SLEEP
WDT
Time-out
Reset
VDD rise
detect
Power-on Reset
VDD
Brown-out
detect
BODEN
S
Q
OST/PWRT
OST
Chip_Reset
10-bit Ripple-counter
R
OSC1/
CLKIN
Pin
On-chip(1)
ER OSC
Q
PWRT
10-bit Ripple-counter
Enable PWRT
See Table 14-3 for time-out situations.
Enable OST
Note 1: This is a separate oscillator from the INTRC/EC oscillator.
DS40300B-page 100
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
14.5
14.5.1
Power-on Reset (POR), Power-up
Timer (PWRT), Oscillator Start-up
Timer (OST) and Brown-out Detect
(BOD)
The Power-Up Time delay will vary from chip to chip
and due to VDD, temperature and process variation.
See DC parameters for details.
POWER-ON RESET (POR)
The Oscillator Start-Up Timer (OST) provides a 1024
oscillator cycle (from OSC1 input) delay after the
PWRT delay is over. This ensures that the crystal
oscillator or resonator has started and stabilized.
14.5.3
The on-chip POR circuit holds the chip in reset until
VDD has reached a high enough level for proper operation. To take advantage of the POR, just tie the MCLR
pin through a resistor to VDD. This will eliminate external RC components usually needed to create Power-on
Reset. A maximum rise time for VDD is required. See
Electrical Specifications for details.
The OST time-out is invoked only for XT, LP and HS
modes and only on power-on reset or wake-up from
SLEEP.
14.5.4
The POR circuit does not produce an internal reset
when VDD declines.
BROWN-OUT DETECT (BOD)
The PIC16F62X members have on-chip Brown-out
Detect circuitry. A configuration bit, BODEN, can disable (if clear/programmed) or enable (if set) the
Brown-out Detect circuitry. If VDD falls below 4.0V, refer
to VBOD parameter D005(VBOD) for greater than
parameter (TBOD) in Table 17.1, the brown-out situation will reset the chip. A reset is not guaranteed to
occur if VDD falls below 4.0V for less than parameter
(TBOD).
When the device starts normal operation (exits the
reset condition), device operating parameters (voltage,
frequency, temperature, etc.) must be met to ensure
operation. If these conditions are not met, the device
must be held in reset until the operating conditions are
met.
For additional information, refer to Application Note
AN607 “Power-up Trouble Shooting”.
14.5.2
OSCILLATOR START-UP TIMER (OST)
On any reset (Power-on, Brown-out, Watchdog, etc.)
the chip will remain in Reset until V DD rises above
BVDD. The Power-up Timer will now be invoked and will
keep the chip in reset an additional 72 ms.
POWER-UP TIMER (PWRT)
The Power-up Timer provides a fixed 72 ms (nominal)
time-out on power-up only, from POR or Brown-out
Reset. The Power-up Timer operates on an internal RC
oscillator. The chip is kept in reset as long as PWRT is
active. The PWRT delay allows the VDD to rise to an
acceptable level. A configuration bit, PWRTE can
disable (if set) or enable (if cleared or programmed) the
Power-up Timer. The Power-up Timer should always be
enabled when Brown-out Reset is enabled.
If VDD drops below BVDD while the Power-up Timer is
running, the chip will go back into a Brown-out Reset
and the Power-up Timer will be re-initialized. Once VDD
rises above BVDD, the Power-Up Timer will execute a
72 ms reset. The Power-up Timer should always be
enabled when Brown-out Detect is enabled.
Figure 14-9 shows typical Brown-out situations.
FIGURE 14-9: BROWN-OUT SITUATIONS
VDD
Internal
Reset
BVDD
72 ms
VDD
Internal
Reset
BVDD
<72 ms
72 ms
VDD
Internal
Reset
 1999 Microchip Technology Inc.
BVDD
72 ms
Preliminary
DS40300B-page 101
PIC16F62X
14.5.5
TIME-OUT SEQUENCE
14.5.6
On power-up the time-out sequence is as follows: First
PWRT time-out is invoked after POR has expired. Then
OST is activated. The total time-out will vary based on
oscillator configuration and PWRTE bit status. For
example, in ER mode with PWRTE bit erased (PWRT
disabled), there will be no time-out at all. Figure 14-10,
Figure 14-11 and Figure 14-12 depict time-out
sequences.
The power control/status register, PCON (address
8Eh) has two bits.
Bit0 is BOD (Brown-out). BOD is unknown on
power-on-reset. It must then be set by the user and
checked on subsequent resets to see if BOD = 0
indicating that a brown-out has occurred. The BOD
status bit is a don’t care and is not necessarily
predictable if the brown-out circuit is disabled (by
setting BODEN bit = 0 in the Configuration word).
Since the time-outs occur from the POR pulse, if MCLR
is kept low long enough, the time-outs will expire. Then
bringing MCLR high will begin execution immediately
(see Figure 14-11). This is useful for testing purposes
or to synchronize more than one PIC16F62X device
operating in parallel.
Bit1 is POR (Power-on-reset). It is a ‘0’ on
power-on-reset and unaffected otherwise. The user
must write a ‘1’ to this bit following a power-on-reset.
On a subsequent reset if POR is ‘0’, it will indicate that
a power-on-reset must have occurred (VDD may have
gone too low).
Table 14-6 shows the reset conditions for some special
registers, while Table 14-7 shows the reset conditions
for all the registers.
TABLE 14-3:
POWER CONTROL (PCON)/
STATUS REGISTER
TIME-OUT IN VARIOUS SITUATIONS
Power-up
Oscillator Configuration
Brown-out Reset
Wake-up
from SLEEP
PWRTE = 0
PWRTE = 1
XT, HS, LP
72 ms + 1024 TOSC
1024 TOSC
72 ms + 1024 TOSC
1024 TOSC
ER
72 ms
—
72 ms
—
TABLE 14-4:
STATUS/PCON BITS AND THEIR SIGNIFICANCE
POR
BOD
TO
PD
0
X
1
1
Power-on-reset
0
X
0
X
Illegal, TO is set on POR
0
X
X
0
Illegal, PD is set on POR
1
0
X
X
Brown-out Detect
1
1
0
u
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
Legend: u = unchanged, x = unknown
TABLE 14-5:
SUMMARY OF REGISTERS ASSOCIATED WITH BROWN-OUT
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on POR
Reset
Value on all
other resets(1)
03h
STATUS
IRP
RP1
RPO
TO
PD
Z
DC
C
0001 1xxx
000q quuu
8Eh
PCON
—
—
—
—
OSCF
—
POR
BOD
---- 1-0x
---- u-uq
Address
Note 1:
Other (non power-up) resets include MCLR reset, Brown-out Detect and Watchdog Timer Reset during normal operation.
DS40300B-page 102
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
TABLE 14-6:
INITIALIZATION CONDITION FOR SPECIAL REGISTERS
Program
Counter
STATUS
Register
PCON
Register
Power-on Reset
000h
0001 1xxx
---- 1-0x
MCLR reset during normal operation
000h
000u uuuu
---- 1-uu
MCLR reset during SLEEP
000h
0001 0uuu
---- 1-uu
WDT reset
000h
0000 uuuu
---- 1-uu
PC + 1
uuu0 0uuu
---- --uu
000h
000x xuuu
---- 1-u0
PC + 1(1)
uuu1 0uuu
---- --uu
Condition
WDT Wake-up
Brown-out Detect
Interrupt Wake-up from SLEEP
Legend: u = unchanged, x = unknown, - = unimplemented bit, reads as ‘0’.
Note 1: When the wake-up is due to an interrupt and global enable bit, GIE is set, the PC is loaded with the interrupt vector
(0004h) after execution of PC+1.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 103
PIC16F62X
TABLE 14-7:
INITIALIZATION CONDITION FOR REGISTERS
Register
Address
Power-on Reset
• MCLR Reset during
normal operation
• MCLR Reset during
SLEEP
• WDT Reset
• Brown-out Detect (1)
• Wake up from
SLEEP through
interrupt
• Wake up from
SLEEP through
WDT time-out
W
-
xxxx xxxx
uuuu uuuu
uuuu uuuu
INDF
00h
-
-
-
TMR0
01h
xxxx xxxx
uuuu uuuu
uuuu uuuu
PCL
02h
0000 0000
0000 0000
PC + 1(3)
STATUS
03h
0001 1xxx
000q quuu(4)
uuuq quuu(4)
FSR
04h
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTA
05h
xxxx 0000
xxxx u000
xxxx 0000
PORTB
06h
xxxx xxxx
uuuu uuuu
uuuu uuuu
T1CON
10h
--00 0000
--uu uuuu
T2CON
12h
-000 0000
-000 0000
CCP1CON
17h
--00 0000
--00 0000
RCSTA
18h
0000 -00x
0000 -00x
CMCON
1Fh
0000 0000
0000 0000
uu-- uuuu
PCLATH
0Ah
---0 0000
---0 0000
---u uuuu
INTCON
0Bh
0000 000x
0000 000u
uuuu uqqq(2)
PIR1
0Ch
0000 -000
0000 -000
-q-- ----(2,5)
OPTION
81h
1111 1111
1111 1111
uuuu uuuu
TRISA
85h
11-1 1111
11-- 1111
uu-u uuuu
TRISB
86h
1111 1111
1111 1111
uuuu uuuu
PIE1
8Ch
0000 -000
0000 -000
uuuu -uuu
1-uq(1,6)
PCON
8Eh
---- 1-0x
TXSTA
98h
0000 -010
0000 -010
EECON1
9Ch
---- x000
---- q000
VRCON
9Fh
000- 0000
000- 0000
----
---- --uu
uuu- uuuu
Legend:
Note 1:
2:
3:
4:
5:
u = unchanged, x = unknown, - = unimplemented bit, reads as ‘0’, q = value depends on condition.
If VDD goes too low, Power-on Reset will be activated and registers will be affected differently.
One or more bits in INTCON, PIR1 and/or PIR2 will be affected (to cause wake-up).
When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector (0004h).
See Table 14-6 for reset value for specific condition.
If wake-up was due to comparator input changing, then bit 6 = 1. All other interrupts generating a wake-up will cause
bit 6 = u.
6: If reset was due to brown-out, then bit 0 = 0. All other resets will cause bit 0 = u.
DS40300B-page 104
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 14-10: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 14-11: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 14-12: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 105
PIC16F62X
FIGURE 14-13: EXTERNAL POWER-ON
RESET CIRCUIT (FOR SLOW
VDD POWER-UP)
FIGURE 14-14: EXTERNAL BROWN-OUT
PROTECTION CIRCUIT 1
VDD
D
VDD
33k
VDD
VDD
10k
MCLR
R
40k
R1
PIC16F62X
MCLR
C
PIC16F62X
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: < 40 kΩ is recommended to make sure that
voltage drop across R does not violate the
device’s electrical specification.
3: R1 = 100Ω to 1 kΩ will limit any current flowing
into MCLR from external capacitor C in the
event of MCLR/VPP pin breakdown due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS).
Note 1: This circuit will activate reset when VDD
goes below (Vz + 0.7V) where Vz = Zener
voltage.
2: Internal Brown-out Reset circuitry should be
disabled when using this circuit.
FIGURE 14-15: EXTERNAL BROWN-OUT
PROTECTION CIRCUIT 2
VDD
VDD
R1
Q1
R2
40k
MCLR
PIC16F62X
Note 1: This brown-out circuit is less expensive,
albeit less accurate. Transistor Q1 turns off
when VDD is below a certain level such that:
R1
= 0.7 V
VDD x
R1 + R2
2: Internal brown-out reset should be disabled
when using this circuit.
3: Resistors should be adjusted for the characteristics of the transistor.
DS40300B-page 106
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
14.6
Interrupts
When an interrupt is responded to, the GIE is cleared
to disable any further interrupt, the return address is
pushed into 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 RB0/INT
recursive interrupts.
The PIC16F62X has 10 sources of interrupt:
•
•
•
•
•
•
•
•
External Interrupt RB0/INT
TMR0 Overflow Interrupt
PortB Change Interrupts (pins RB7:RB4)
Comparator Interrupt
USART Interrupt
CCP Interrupt
TMR1 Overflow Interrupt
TMR2 Match Interrupt
The interrupt control register (INTCON) records
individual interrupt requests in flag bits. It also has
individual and global interrupt enable bits.
A global interrupt enable bit, GIE (INTCON<7>)
enables (if set) all un-masked interrupts or disables (if
cleared) all interrupts. Individual interrupts can be
disabled through their corresponding enable bits in
INTCON register. GIE is cleared on reset.
The “return from interrupt” instruction, RETFIE, exits
interrupt routine as well as sets the GIE bit, which
re-enable RB0/INT interrupts.
For external interrupt events, such as the INT pin or
PORTB change interrupt, the interrupt latency will be
three or four instruction cycles. The exact latency
depends when the interrupt event occurs
(Figure 14-17). The latency is the same for one or two
cycle instructions. 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 multiple interrupt requests. Individual interrupt
flag bits are set regardless of the status of their
corresponding mask bit or the GIE bit.
Note 1:
Individual interrupt flag bits are set
regardless of the status of their
corresponding mask bit or the GIE bit.
2:
When an instruction that clears the GIE
bit is executed, any interrupts that were
pending for execution in the next cycle
are ignored. The CPU will execute a
NOP in the cycle immediately following
the instruction which clears the GIE bit.
The interrupts which were ignored are
still pending to be serviced when the GIE
bit is set again.
The INT pin interrupt, the RB port change interrupt and
the TMR0 overflow interrupt flags are contained in the
INTCON register.
The peripheral interrupt flag is contained in the special
register PIR1. The corresponding interrupt enable bit is
contained in special registers PIE1.
FIGURE 14-16: INTERRUPT LOGIC
TMR1IF
TMR1IE
TMR2IF
TMR2IE
CCP1IF
CCP1IE
CMIF
CMIE
TXIF
TXIE
RCIF
RCIE
EEIF
EEIE
 1999 Microchip Technology Inc.
Wake-up (If in SLEEP mode)
T0IF
T0IE
INTF
INTE
Interrupt to CPU
RBIF
RBIE
PEIE
GIE
Preliminary
DS40300B-page 107
PIC16F62X
14.6.1
RB0/INT INTERRUPT
14.6.3
External interrupt on RB0/INT pin is edge triggered:
either rising if INTEDG bit (OPTION<6>) is set, or falling, if INTEDG bit is clear. When a valid edge appears
on the RB0/INT pin, the INTF bit (INTCON<1>) is set.
This interrupt can be disabled by clearing the INTE
control bit (INTCON<4>). The INTF bit must be cleared
in software in the interrupt service routine before
re-enabling this interrupt. The RB0/INT interrupt can
wake-up the processor from SLEEP, if the INTE bit was
set prior to going into SLEEP. The status of the GIE bit
decides whether or not the processor branches to the
interrupt vector following wake-up. See Section 14.9 for
details on SLEEP and Figure 14-19 for timing of
wake-up from SLEEP through RB0/INT interrupt.
14.6.2
PORTB INTERRUPT
An input change on PORTB <7:4> sets the RBIF
(INTCON<0>) bit. The interrupt can be enabled/disabled by setting/clearing the RBIE (INTCON<4>) bit.
For operation of PORTB (Section 5.2).
Note:
14.6.4
If a change on the I/O pin should occur
when the read operation is being executed
(start of the Q2 cycle), then the RBIF interrupt flag may not get set.
COMPARATOR INTERRUPT
See Section 9.6 for complete description of comparator
interrupts.
TMR0 INTERRUPT
An overflow (FFh → 00h) in the TMR0 register will
set the T0IF (INTCON<2>) bit. The interrupt can
be enabled/disabled by setting/clearing T0IE
(INTCON<5>) bit. For operation of the Timer0 module,
see Section 6.0.
FIGURE 14-17: INT PIN INTERRUPT TIMING
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
OSC1
CLKOUT 3
4
INT pin
1
1
INTF flag
(INTCON<1>)
Interrupt Latency 2
5
GIE bit
(INTCON<7>)
INSTRUCTION FLOW
PC
Instruction
fetched
Inst (PC)
Instruction
executed
Inst (PC-1)
0004h
PC+1
PC+1
PC
Inst (0004h)
Inst (0005h)
Dummy Cycle
Inst (0004h)
—
Inst (PC+1)
Dummy Cycle
Inst (PC)
0005h
Note 1: INTF flag is sampled here (every Q1).
2: Asynchronous interrupt latency = 3-4 Tcy. Synchronous latency = 3 Tcy, where Tcy = instruction cycle time. Latency
is the same whether Inst (PC) is a single cycle or a 2-cycle instruction.
3: CLKOUT is available only in ER oscillator mode.
4: For minimum width of INT pulse, refer to AC specs.
5: INTF is enabled to be set anytime during the Q4-Q1 cycles.
TABLE 14-8:
Address
SUMMARY OF INTERRUPT REGISTERS
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on POR
Reset
Value on all
other resets(1)
0Bh
INTCON
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x
0000 000u
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
0000 -000
8Ch
PIE1
EEIE
CMIE
RCIE
TXIE
—
CCP1IE
TMR2IE
TMR1IE
0000 -000
0000 -000
Note 1:
Other (non power-up) resets include MCLR reset, Brown-out Reset and Watchdog Timer Reset during normal operation.
DS40300B-page 108
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
14.7
Context Saving During Interrupts
14.8
During an interrupt, only the return PC value is saved
on the stack. Typically, users may wish to save key registers during an interrupt e.g. W register and STATUS
register. This will have to be implemented in software.
Example 14-1 stores and restores the STATUS and W
registers. The user register, W_TEMP, must be defined
in both banks and must be defined at the same offset
from the bank base address (i.e., W_TEMP is defined
at 0x20 in Bank 0 and it must also be defined at 0xA0
in Bank 1). The user register, STATUS_TEMP, must be
defined in Bank 0. The Example 14-1:
•
•
•
•
Stores the W register
Stores the STATUS register in Bank 0
Executes the ISR code
Restores the STATUS (and bank select bit
register)
• Restores the W register
MOVWF
W_TEMP
;copy W to temp register,
;could be in either bank
SWAPF
STATUS,W
;swap status to be saved into W
BCF
STATUS,RP0
;change to bank 0 regardless
;of current bank
MOVWF
STATUS_TEMP
;save status to bank 0
;register
The WDT has a nominal time-out period of 18 ms, (with
no prescaler). The time-out periods vary with temperature, VDD and process variations from part to part (see
DC specs). If longer time-out periods are desired, a
prescaler with a division ratio of up to 1:128 can be
assigned to the WDT under software control by writing
to the OPTION register. Thus, time-out periods up to
2.3 seconds can be realized.
The CLRWDT and SLEEP instructions clear the WDT
and the postscaler, if assigned to the WDT, and prevent
it from timing out and generating a device RESET.
14.8.2
(ISR)
:
SWAPF
STATUS_TEMP,W
;swap STATUS_TEMP register
;into W, sets bank to original
;state
MOVWF
STATUS
;move W into STATUS register
SWAPF
W_TEMP,F
;swap W_TEMP
SWAPF
W_TEMP,W
;swap W_TEMP into W
 1999 Microchip Technology Inc.
WDT PERIOD
The TO bit in the STATUS register will be cleared upon
a Watchdog Timer time-out.
:
:
The watchdog timer is a free running on-chip RC oscillator which does not require any external components.
This RC oscillator is separate from the ER oscillator of
the CLKIN pin. That means that the WDT will run, even
if the clock on the OSC1 and OSC2 pins 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. If the device is in
SLEEP mode, a WDT time-out causes the device to
wake-up and continue with normal operation. The WDT
can be permanently disabled by programming the configuration bit WDTE as clear (Section 14.1).
14.8.1
EXAMPLE 14-1: SAVING THE STATUS AND
W REGISTERS IN RAM
Watchdog Timer (WDT)
WDT PROGRAMMING CONSIDERATIONS
It should also be taken in account that under worst case
conditions (VDD = Min., Temperature = Max., max.
WDT prescaler) it may take several seconds before a
WDT time-out occurs.
Preliminary
DS40300B-page 109
PIC16F62X
FIGURE 14-18: WATCHDOG TIMER BLOCK DIAGRAM
From TMR0 Clock Source
(Figure 6-6)
0
Watchdog
Timer
M
U
X
1
•
Postscaler
8
8 - to -1 MUX
PS<2:0>
•
To TMR0 (Figure 6-6)
PSA
WDT
Enable Bit
1
0
MUX
PSA
WDT
Time-out
Note: T0SE, T0CS, PSA, PS0-PS2 are bits in the OPTION register.
TABLE 14-9:
SUMMARY OF WATCHDOG TIMER REGISTERS
Address
Name
2007h
Config. bits
81h
OPTION
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Reset
LVP
BOREN
MCLRE
FOSC2
PWRTE
WDTE
FOSC1
FOSC0
uuuu uuuu
uuuu uuuu
RBPU
INTEDG
T0CS
T0SE
PSA
PS2
PS1
PS0
1111 1111
1111 1111
Bit 7
Value on
all other
Resets
Legend: Shaded cells are not used by the Watchdog Timer.
Note:
_
= Unimplemented location, read as “0”
+ = Reserved for future use
DS40300B-page 110
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
14.9
Power-Down Mode (SLEEP)
The Power-down mode is entered by executing a
SLEEP instruction.
If enabled, the Watchdog Timer will be cleared but
keeps running, the PD bit in the STATUS register is
cleared, the TO bit is set, and the oscillator driver is
turned off. The I/O ports maintain the status they had,
before SLEEP was executed (driving high, low, or
hi-impedance).
For lowest current consumption in this mode, all I/O
pins should be either at VDD, or VSS, with no external
circuitry drawing current from the I/O pin and the comparators and VREF should be disabled. I/O pins that are
hi-impedance inputs should be pulled 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
on chip pull-ups on PORTB should be considered.
The first event will cause a device reset. The two latter
events are considered a continuation of program execution. The TO and PD bits in the STATUS register can
be used to determine the cause of device reset. PD
bit, which is set on power-up is cleared when SLEEP is
invoked. TO bit is cleared if WDT Wake-up occurred.
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 and then branches to the interrupt address (0004h). In cases where the execution of
the instruction following SLEEP is not desirable, the
user should have an NOP after the SLEEP instruction.
Note:
The MCLR pin must be at a logic high level (VIHMC).
Note:
14.9.1
It should be noted that a RESET generated
by a WDT time-out does not drive MCLR
pin low.
WAKE-UP FROM SLEEP
The device can wake-up from SLEEP through one of
the following events:
1.
2.
3.
If the global interrupts are disabled (GIE is
cleared), but any interrupt source has both
its interrupt enable bit and the corresponding interrupt flag bits set, the device will
immediately wakeup from sleep. The sleep
instruction is completely executed.
The WDT is cleared when the device wakes-up from
sleep, regardless of the source of wake-up.
External reset input on MCLR pin
Watchdog Timer Wake-up (if WDT was enabled)
Interrupt from RB0/INT pin, RB Port change, or
the Peripheral Interrupt (Comparator).
FIGURE 14-19: 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
PC + 2
0004h
0005h
Inst(0004h)
Inst(0005h)
Dummy cycle
Inst(0004h)
Q4
OSC1
TOST(2)
CLKOUT(4)
INT pin
INTF flag
(INTCON<1>)
Interrupt Latency
(Note 2)
GIE bit
(INTCON<7>)
Processor in
SLEEP
INSTRUCTION FLOW
PC
PC
Instruction
fetched
Inst(PC) = SLEEP
Instruction
executed
Inst(PC - 1)
Note 1:
2:
3:
4:
PC+1
PC+2
PC+2
Inst(PC + 1)
Inst(PC + 2)
SLEEP
Inst(PC + 1)
Dummy cycle
XT, HS or LP oscillator mode assumed.
TOST = 1024TOSC (drawing not to scale). Approximately 1 µs delay will be there for ER osc mode.
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.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 111
PIC16F62X
14.10
Code Protection
If the code protection bit(s) have not been
programmed, the on-chip program memory can be
read out for verification purposes.
Note:
14.11
The entire data EEPROM and FLASH
program memory will be erased when the
code protection is turned off. The INTRC
calibration data is not erased.
FIGURE 14-20: TYPICAL IN-CIRCUIT SERIAL
PROGRAMMING
CONNECTION
External
Connector
Signals
ID Locations
Four memory locations (2000h-2003h) are designated
as ID locations where the user can store checksum or
other code-identification numbers. These locations are
not accessible during normal execution but are
readable and writable during program/verify. Only the
least significant 4 bits of the ID locations are used.
14.12
To Normal
Connections
PIC16F62X
+5V
VDD
0V
VSS
VPP
RA5/MCLR/THV
CLK
RB6
Data I/O
RB7
VDD
In-Circuit Serial Programming
The PIC16F62X microcontrollers can be serially
programmed while in the end application circuit. This is
simply done with two lines for clock and data, and three
other lines for power, ground, and the programming
voltage. This allows customers to manufacture boards
with unprogrammed devices, and then program the
microcontroller just before shipping the product. This
also allows the most recent firmware or a custom
firmware to be programmed.
The device is placed into a program/verify mode by
holding the RB6 and RB7 pins low while raising the
MCLR (VPP) pin from VIL to VIHH (see programming
specification). RB6 becomes the programming clock
and RB7 becomes the programming data. Both RB6
and RB7 are Schmitt Trigger inputs in this mode.
After reset, to place the device into programming/verify
mode, the program counter (PC) is at location 00h. A
6-bit command is then supplied to the device.
Depending on the command, 14-bits of program data
are then supplied to or from the device, depending if the
command was a load or a read. For complete details of
serial programming, please refer to the Programming
Specifications.
To Normal
Connections
14.13
Low Voltage Programming
The LVP bit of the configuration word, enables the low
voltage programming. This mode allows the microcontroller to be programmed via ICSP using only a 5V
source. This mode removes the requirement of VIHH to
be placed on the MCLR pin. The LVP bit is normally
erased to ’1’ which enables the low voltage programming. In this mode, the RB4/PGM pin is dedicated to
the programming function and ceases to be a general
purpose I/O pin. The device will enter programming
mode when a ’1’ is placed on the RB4/PGM pin. The
HV programming mode is still available by placing VIHH
on the MCLR pin.
Note 1: While in this mode the RB4 pin can no
longer be used as a general purpose I/O
pin.
2: VDD must be 5.0V +10% during erase/program operations while in low voltage programming mode.
A typical in-circuit serial programming connection is
shown in Figure 14-20.
If Low-voltage programming mode is not used, the LVP
bit can be programmed to a ’0’ and RB4/PGM becomes
a digital I/O pin. To program the device, VIHH must be
placed onto MCLR during programming. The LVP bit
may only be programmed when programming is
entered with VIHH on MCLR. The LVP bit cannot be
programmed when programming is entered with
RB4/PGM.
It should be noted, that once the LVP bit is programmed
to 0, only the high voltage programming mode is available and only high voltage programming mode can be
used to program the device.
DS40300B-page 112
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
15.0
INSTRUCTION SET SUMMARY
Each PIC16F62X 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 PIC16F62X instruction set summary in Table 15-2 lists byte-oriented,
bit-oriented, and literal and control operations.
Table 15-1 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.
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.
For literal and control operations, ’k’ represents an
eight or eleven bit constant or literal value.
TABLE 15-1:
OPCODE FIELD
DESCRIPTIONS
Field
• Byte-oriented operations
• Bit-oriented operations
• Literal and control operations
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 µs. If a
conditional test is true or the program counter is
changed as a result of an instruction, the instruction
execution time is 2 µs.
Table 15-1 lists the instructions recognized by the
MPASM assembler.
Figure 15-1 shows the three general formats that the
instructions can have.
Note:
To maintain upward compatibility with
future PICmicro® products, do not use the
OPTION and TRIS instructions.
All examples use the following format to represent a
hexadecimal number:
Description
0xhh
f
Register file address (0x00 to 0x7F)
W
Working register (accumulator)
b
Bit address within an 8-bit file register
k
Literal field, constant data or label
x
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.
d
The instruction set is highly orthogonal and is grouped
into three basic categories:
where h signifies a hexadecimal digit.
FIGURE 15-1: GENERAL FORMAT FOR
INSTRUCTIONS
Byte-oriented file register operations
13
8 7 6
OPCODE
d
f (FILE #)
Destination select; d = 0: store result in W,
d = 1: store result in file register f.
Default is d = 1
0
d = 0 for destination W
d = 1 for destination f
f = 7-bit file register address
label Label name
TOS
PC
Top of Stack
Bit-oriented file register operations
13
10 9
7 6
OPCODE
b (BIT #)
f (FILE #)
Program Counter
PCLATH Program Counter High Latch
GIE
Global Interrupt Enable bit
WDT
Watchdog Timer/Counter
TO
Time-out bit
PD
Power-down bit
b = 3-bit bit address
f = 7-bit file register address
Literal and control operations
dest Destination either the W register or the specified
register file location
[ ]
Options
( )
→
<>
∈
Contents
0
General
13
8
7
OPCODE
Assigned to
0
k (literal)
k = 8-bit immediate value
Register bit field
In the set of
CALL and GOTO instructions only
italics User defined term (font is courier)
13
11
OPCODE
10
0
k (literal)
k = 11-bit immediate value
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 113
PIC16F62X
TABLE 15-2:
PIC16F62X INSTRUCTION SET
Mnemonic,
Operands
Description
Cycles
14-Bit Opcode
MSb
LSb
Status
Affected
Notes
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
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
1
1
1 (2)
1 (2)
01
01
01
01
00bb
01bb
10bb
11bb
bfff
bfff
bfff
bfff
ffff
ffff
ffff
ffff
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
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
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
1,2
1,2
3
3
LITERAL AND CONTROL OPERATIONS
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
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 Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is
executed as a NOP.
DS40300B-page 114
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
15.1
Instruction Descriptions
ANDLW
AND Literal with W
Syntax:
[ label ] ANDLW
ADDLW
Add Literal and W
Syntax:
[ label ] ADDLW
Operands:
0 ≤ k ≤ 255
Operands:
0 ≤ k ≤ 255
Operation:
(W) + k → (W)
Operation:
(W) .AND. (k) → (W)
Status Affected:
C, DC, Z
Status Affected:
Z
Encoding:
11
k
111x
kkkk
kkkk
Encoding:
11
k
1001
kkkk
kkkk
Description:
The contents of the W register are
added to the eight bit literal ’k’ and the
result is placed in the W register.
Description:
The contents of W register are
AND’ed with the eight bit literal 'k'. The
result is placed in the W register.
Words:
1
Words:
1
Cycles:
1
Cycles:
1
Example
ADDLW
Example
0x15
=
W
0x10
ADDWF
=
=
0xA3
After Instruction
After Instruction
W
0x5F
Before Instruction
Before Instruction
W
ANDLW
W
0x25
Add W and f
ANDWF
=
0x03
AND W with f
Syntax:
[ label ] ADDWF
Syntax:
[ label ] ANDWF
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operation:
(W) + (f) → (dest)
Operation:
(W) .AND. (f) → (dest)
Status Affected:
C, DC, Z
Status Affected:
Z
Encoding:
00
f,d
0111
dfff
ffff
Encoding:
00
f,d
0101
dfff
ffff
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:
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'.
Words:
1
Words:
1
Cycles:
1
Cycles:
1
Example
ADDWF
FSR, 0
Example
Before Instruction
W =
FSR =
 1999 Microchip Technology Inc.
FSR, 1
Before Instruction
0x17
0xC2
W =
FSR =
After Instruction
W =
FSR =
ANDWF
0x17
0xC2
After Instruction
0xD9
0xC2
W =
FSR =
Preliminary
0x17
0x02
DS40300B-page 115
PIC16F62X
BCF
Bit Clear f
BTFSC
Bit Test, Skip if Clear
Syntax:
[ label ] BCF
Syntax:
[ label ] BTFSC f,b
Operands:
0 ≤ f ≤ 127
0≤b≤7
Operands:
0 ≤ f ≤ 127
0≤b≤7
Operation:
0 → (f<b>)
Operation:
skip if (f<b>) = 0
Status Affected:
None
Status Affected:
None
Encoding:
01
f,b
00bb
bfff
ffff
Description:
Bit ’b’ in register ’f’ is cleared.
Words:
1
Cycles:
1
Example
BCF
Encoding:
FLAG_REG = 0x47
bfff
ffff
If bit ’b’ in register ’f’ is ’0’ then the next
instruction is skipped.
If bit ’b’ is ’0’ then the next instruction
fetched during the current instruction
execution is discarded, and a NOP is
executed instead, making this a
two-cycle instruction.
Words:
1
Cycles:
1(2)
Before Instruction
FLAG_REG = 0xC7
10bb
Description:
FLAG_REG, 7
After Instruction
01
Example
HERE
FALSE
TRUE
BTFSC
GOTO
•
•
•
FLAG,1
PROCESS_CODE
Before Instruction
PC =
address HERE
After Instruction
if FLAG<1> = 0,
PC =
address TRUE
if FLAG<1>=1,
PC =
address FALSE
BSF
Bit Set f
Syntax:
[ label ] BSF
Operands:
0 ≤ f ≤ 127
0≤b≤7
Operation:
1 → (f<b>)
Status Affected:
None
Encoding:
Description:
01
01bb
bfff
ffff
Bit ’b’ in register ’f’ is set.
Words:
1
Cycles:
1
Example
f,b
BSF
FLAG_REG,
7
Before Instruction
FLAG_REG = 0x0A
After Instruction
FLAG_REG = 0x8A
DS40300B-page 116
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
BTFSS
Bit Test f, Skip if Set
CLRF
Clear f
Syntax:
[ label ] BTFSS f,b
Syntax:
[ label ] CLRF
Operands:
0 ≤ f ≤ 127
0≤b<7
Operands:
0 ≤ f ≤ 127
Operation:
Operation:
skip if (f<b>) = 1
00h → (f)
1→Z
Status Affected:
None
Status Affected:
Z
Encoding:
Description:
01
11bb
bfff
ffff
If bit ’b’ in register ’f’ is ’1’ then the next
instruction is skipped.
If bit ’b’ is ’1’, then the next instruction
fetched during the current instruction
execution, is discarded and a NOP is
executed instead, making this a
two-cycle instruction.
Words:
1
Cycles:
1(2)
Example
HERE
FALSE
TRUE
Encoding:
00
f
0001
1fff
ffff
Description:
The contents of register ’f’ are cleared
and the Z bit is set.
Words:
1
Cycles:
1
Example
CLRF
FLAG_REG
Before Instruction
FLAG_REG
BTFSS
GOTO
•
•
•
=
0x5A
=
=
0x00
1
After Instruction
FLAG,1
PROCESS_CODE
FLAG_REG
Z
Before Instruction
PC =
address HERE
After Instruction
if FLAG<1> = 0,
PC =
address FALSE
if FLAG<1> = 1,
PC =
address TRUE
CALL
Call Subroutine
CLRW
Clear W
Syntax:
[ label ] CALL k
Syntax:
[ label ] CLRW
Operands:
0 ≤ k ≤ 2047
Operands:
None
Operation:
(PC)+ 1→ TOS,
k → PC<10:0>,
(PCLATH<4:3>) → PC<12:11>
Operation:
00h → (W)
1→Z
Status Affected:
Z
Status Affected:
None
Encoding:
Encoding:
Description:
10
kkkk
kkkk
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.
Words:
1
Cycles:
2
Example
0kkk
00
0001
0000
0011
Description:
W register is cleared. Zero bit (Z) is
set.
Words:
1
Cycles:
1
Example
CLRW
Before Instruction
W
HERE
CALL
=
0x5A
After Instruction
THERE
W
Z
Before Instruction
=
=
0x00
1
PC = Address HERE
After Instruction
PC = Address THERE
TOS = Address HERE+1
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 117
PIC16F62X
CLRWDT
Clear Watchdog Timer
DECF
Decrement f
Syntax:
[ label ] CLRWDT
Syntax:
[ label ] DECF f,d
Operands:
None
Operands:
Operation:
00h → WDT
0 → WDT prescaler,
1 → TO
1 → PD
0 ≤ f ≤ 127
d ∈ [0,1]
Operation:
(f) - 1 → (dest)
Status Affected:
Z
Status Affected:
Encoding:
Description:
Encoding:
TO, PD
00
0000
0110
0100
CLRWDT instruction resets the
Watchdog Timer. It also resets the
prescaler of the WDT. Status bits TO
and PD are set.
Words:
1
Cycles:
1
Example
00
0011
dfff
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’.
Words:
1
Cycles:
1
Example
DECF
CNT, 1
Before Instruction
CLRWDT
CNT
Z
Before Instruction
WDT counter =
WDT counter =
WDT prescaler=
TO
=
PD
=
COMF
Complement f
Syntax:
[ label ] COMF
Operands:
=
=
0x01
0
=
=
0x00
1
After Instruction
?
CNT
Z
After Instruction
0x00
0
1
1
DECFSZ
Decrement f, Skip if 0
Syntax:
[ label ] DECFSZ f,d
0 ≤ f ≤ 127
d ∈ [0,1]
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operation:
(f) → (dest)
Operation:
(f) - 1 → (dest);
Status Affected:
Z
Status Affected:
None
Encoding:
Description:
00
1
Cycles:
1
Example
1001
f,d
dfff
ffff
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’.
Words:
ffff
Description:
COMF
REG1,0
Before Instruction
REG1
=
0x13
=
=
0x13
0xEC
After Instruction
REG1
W
Encoding:
Description:
00
dfff
ffff
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 0, the next instruction,
which is already fetched, is discarded. A
NOP is executed instead making it a
two-cycle instruction.
Words:
1
Cycles:
1(2)
Example
1011
skip if result = 0
HERE
DECFSZ
GOTO
CONTINUE •
•
•
CNT, 1
LOOP
Before Instruction
PC
=
address HERE
After Instruction
CNT
if CNT
PC
if CNT
PC
DS40300B-page 118
Preliminary
=
=
=
≠
=
CNT - 1
0,
address CONTINUE
0,
address HERE+1
 1999 Microchip Technology Inc.
PIC16F62X
GOTO
Unconditional Branch
INCFSZ
Increment f, Skip if 0
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ k ≤ 2047
Operands:
Operation:
k → PC<10:0>
PCLATH<4:3> → PC<12:11>
0 ≤ f ≤ 127
d ∈ [0,1]
Operation:
(f) + 1 → (dest), skip if result = 0
None
Status Affected:
None
Status Affected:
Encoding:
Description:
GOTO k
10
1kkk
kkkk
kkkk
GOTO is an unconditional branch. The
eleven bit immediate value is loaded
into PC bits <10:0>. The upper bits of
PC are loaded from PCLATH<4:3>.
GOTO is a two-cycle instruction.
Words:
1
Cycles:
2
Example
GOTO THERE
After Instruction
PC =
Address THERE
Encoding:
00
INCFSZ f,d
1111
dfff
ffff
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 0, the next instruction,
which is already fetched, is discarded.
A NOP is executed instead making it a
two-cycle instruction.
Words:
1
Cycles:
1(2)
Example
HERE
INCFSZ
GOTO
CONTINUE •
•
•
CNT,
LOOP
1
Before Instruction
PC
=
address HERE
After Instruction
CNT =
if CNT=
PC
=
if CNT≠
PC
=
CNT + 1
0,
address CONTINUE
0,
address HERE +1
INCF
Increment f
IORLW
Inclusive OR Literal with W
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operands:
0 ≤ k ≤ 255
(f) + 1 → (dest)
Operation:
(W) .OR. k → (W)
Operation:
Status Affected:
Z
Status Affected:
Z
Encoding:
Description:
INCF f,d
Encoding:
00
1010
dfff
ffff
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:
1
1
Words:
1
Cycles:
1
Example
INCF
1000
kkkk
IORLW
0x35
Before Instruction
CNT, 1
W
Before Instruction
CNT
Z
kkkk
The contents of the W register is
OR’ed with the eight bit literal 'k'. The
result is placed in the W register.
Words:
Cycles:
Example
11
IORLW k
=
0x9A
After Instruction
=
=
0xFF
0
=
=
0x00
1
W
Z
=
=
0xBF
1
After Instruction
CNT
Z
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 119
PIC16F62X
IORWF
Inclusive OR W with f
MOVF
Move f
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operation:
(W) .OR. (f) → (dest)
Operation:
(f) → (dest)
Status Affected:
Z
Status Affected:
Z
Encoding:
00
IORWF
f,d
0100
dfff
ffff
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’.
Words:
1
Cycles:
1
Example
IORWF
RESULT, 0
Before Instruction
RESULT =
W
=
0x13
0x91
Encoding:
Description:
00
1000
1
Cycles:
1
Example
MOVF
FSR, 0
0x13
0x93
1
W = value in FSR register
Z =1
MOVLW
Move Literal to W
MOVWF
Move W to f
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ k ≤ 255
Operands:
0 ≤ f ≤ 127
Operation:
k → (W)
Operation:
(W) → (f)
Status Affected:
None
Status Affected:
None
11
MOVLW k
00xx
kkkk
kkkk
Description:
The eight bit literal ’k’ is loaded into W
register. The don’t cares will assemble
as 0’s.
Words:
1
Cycles:
1
Example
Encoding:
1fff
ffff
Words:
1
Cycles:
1
MOVWF
OPTION
Before Instruction
After Instruction
=
0000
f
Move data from W register to register
'f'.
0x5A
W
00
MOVWF
Description:
Example
MOVLW
ffff
After Instruction
RESULT =
W
=
Z
=
Encoding:
dfff
The contents of register f is moved to
a destination dependent upon the
status of d. If d = 0, destination is W
register. If d = 1, the destination is file
register f itself. d = 1 is useful to test a
file register since status flag Z is
affected.
Words:
After Instruction
MOVF f,d
OPTION =
W
=
0x5A
0xFF
0x4F
After Instruction
OPTION =
W
=
DS40300B-page 120
Preliminary
0x4F
0x4F
 1999 Microchip Technology Inc.
PIC16F62X
NOP
No Operation
RETFIE
Return from Interrupt
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
None
Operands:
None
Operation:
No operation
Operation:
Status Affected:
None
TOS → PC,
1 → GIE
Status Affected:
None
Encoding:
00
NOP
0000
Description:
No operation.
Words:
1
Cycles:
1
Example
0xx0
0000
Encoding:
RETFIE
00
0000
0000
1001
Description:
Return from Interrupt. Stack is POPed
and Top of Stack (TOS) is loaded in
the PC. Interrupts are enabled by
setting Global Interrupt Enable bit,
GIE (INTCON<7>). This is a two-cycle
instruction.
Words:
1
Cycles:
2
NOP
Example
RETFIE
After Interrupt
PC =
GIE =
TOS
1
OPTION
Load Option Register
RETLW
Return with Literal in W
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
None
Operands:
0 ≤ k ≤ 255
Operation:
(W) → OPTION
Operation:
k → (W);
TOS → PC
Status Affected:
None
OPTION
Status Affected: None
Encoding:
Description:
00
0000
0110
0010
The contents of the W register are
loaded in the OPTION register. This
instruction is supported for code
compatibility with PIC16C5X products.
Since OPTION is a readable/writable
register, the user can directly
address it.
Encoding:
RETLW k
11
01xx
kkkk
Description:
The W register is loaded with the eight
bit literal ’k’. The program counter is
loaded from the top of the stack (the
return address). This is a two-cycle
instruction.
Words:
1
Words:
1
Cycles:
1
Cycles:
2
Example
CALL TABLE
Example
kkkk
To maintain upward compatibility
with future PICmicro® products, do
not use this instruction.
•
value
•
TABLE •
ADDWF
RETLW
RETLW
•
•
•
RETLW
;W contains table
;offset value
;W now has table
PC
k1
k2
;W = offset
;Begin table
;
kn
; End of table
Before Instruction
W
=
0x07
After Instruction
W
 1999 Microchip Technology Inc.
Preliminary
=
value of k8
DS40300B-page 121
PIC16F62X
RETURN
Return from Subroutine
Syntax:
[ label ]
Operands:
None
Operation:
TOS → PC
Status Affected:
None
Encoding:
Description:
RETURN
00
0000
0000
1000
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.
Words:
1
Cycles:
2
Example
RRF
Rotate Right f through Carry
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operation:
See description below
Status Affected:
C
Encoding:
Description:
RRF f,d
00
1100
dfff
ffff
The contents of register ’f’ are rotated
one bit to the right through the Carry
Flag. If ’d’ is 0 the result is placed in
the W register. If ’d’ is 1 the result is
placed back in register ’f’.
C
Register f
RETURN
After Interrupt
PC =
TOS
Words:
1
Cycles:
1
Example
RRF
REG1,0
Before Instruction
REG1
C
=
=
1110 0110
0
=
=
=
1110 0110
0111 0011
0
After Instruction
REG1
W
C
RLF
Rotate Left f through Carry
SLEEP
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operands:
None
Operation:
00h → WDT,
0 → WDT prescaler,
1 → TO,
0 → PD
Status Affected:
TO, PD
RLF
f,d
Operation:
See description below
Status Affected:
C
Encoding:
Description:
00
1101
C
Words:
1
Cycles:
1
Example
dfff
ffff
The contents of register ’f’ are rotated
one bit to the left through the Carry
Flag. If ’d’ is 0 the result is placed in
the W register. If ’d’ is 1 the result is
stored back in register ’f’.
RLF
Encoding:
Before Instruction
REG1
C
=
=
1110 0110
0
=
=
=
1110 0110
1100 1100
1
0000
0110
0011
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.
See Section 14.9 for more details.
Words:
1
Cycles:
1
Example:
SLEEP
Register f
REG1,0
00
SLEEP
After Instruction
REG1
W
C
DS40300B-page 122
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
SUBLW
Subtract W from Literal
SUBWF
Subtract W from f
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operation:
(f) - (W) → (dest)
Status
Affected:
C, DC, Z
Encoding:
00
SUBLW k
Operands:
0 ≤ k ≤ 255
Operation:
k - (W) → (W)
Status
Affected:
C, DC, Z
Encoding:
Description:
11
110x
kkkk
kkkk
The W register is subtracted (2’s complement method) from the eight bit literal
'k'. The result is placed in the W register.
Words:
1
Cycles:
1
Example 1:
SUBLW
0x02
Before Instruction
W
C
=
=
Example 2:
=
=
=
=
Example 3:
=
=
1
Cycles:
1
Example 1:
SUBWF
=
=
REG1
W
C
1
1; result is positive
=
=
=
3
2
?
After Instruction
REG1
W
C
2
?
Example 2:
0
1; result is zero
=
=
=
1
2
1; result is positive
Before Instruction
REG1
W
C
=
=
=
2
2
?
After Instruction
3
?
REG1
W
C
After Instruction
W =
C
=
tive
REG1,1
Before Instruction
Before Instruction
W
C
ffff
Words:
1
?
After Instruction
W
C
dfff
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'.
Before Instruction
W
C
0010
Description:
After Instruction
W
C
SUBWF f,d
0xFF
0; result is nega-
Example 3:
=
=
=
0
2
1; result is zero
Before Instruction
REG1
W
C
=
=
=
1
2
?
After Instruction
REG1
W
C
 1999 Microchip Technology Inc.
Preliminary
=
=
=
0xFF
2
0; result is negative
DS40300B-page 123
PIC16F62X
SWAPF
Swap Nibbles in f
XORLW
Exclusive OR Literal with W
Syntax:
[ label ] SWAPF f,d
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operands:
0 ≤ k ≤ 255
Operation:
(f<3:0>) → (dest<7:4>),
(f<7:4>) → (dest<3:0>)
Operation:
(W) .XOR. k → (W)
Status Affected:
Z
None
Encoding:
Status Affected:
Encoding:
Description:
00
1110
dfff
ffff
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’.
11
1
1
Cycles:
1
Example:
XORLW
0xAF
Before Instruction
0
W
Before Instruction
=
W
=
=
=
0xB5
After Instruction
0xA5
After Instruction
REG1
W
=
0x1A
0xA5
0x5A
TRIS
Load TRIS Register
XORWF
Exclusive OR W with f
Syntax:
[ label ] XORWF
Operands:
0 ≤ f ≤ 127
d ∈ [0,1]
Operation:
(W) .XOR. (f) → (dest)
Status Affected:
Z
Syntax:
[ label ] TRIS
Operands:
5≤f≤7
Operation:
(W) → TRIS register f;
f
Status Affected: None
Encoding:
Description:
00
0000
0110
0fff
The instruction is supported for code
compatibility with the PIC16C5X
products. Since TRIS registers are
readable and writable, the user can
directly address them.
Words:
1
Cycles:
1
kkkk
Words:
Cycles:
REG1
kkkk
The contents of the W register are
XOR’ed with the eight bit literal 'k'.
The result is placed in the
W register.
1
SWAPF REG,
1010
Description:
Words:
Example
XORLW k
Example
To maintain upward compatibility
with future PICmicro® products, do
not use this instruction.
Encoding:
00
0110
f,d
dfff
ffff
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'.
Words:
1
Cycles:
1
Example
XORWF
REG
1
Before Instruction
REG
W
=
=
0xAF
0xB5
=
=
0x1A
0xB5
After Instruction
REG
W
DS40300B-page 124
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
16.0
DEVELOPMENT SUPPORT
PICmicro®
MPLAB allows you to:
The
microcontrollers are supported with a
full range of hardware and software development tools:
• Integrated Development Environment
- MPLAB™ IDE Software
• Assemblers/Compilers/Linkers
- MPASM Assembler
- MPLAB-C17 and MPLAB-C18 C Compilers
- MPLINK/MPLIB Linker/Librarian
• Simulators
- MPLAB-SIM Software Simulator
• Emulators
- MPLAB-ICE Real-Time In-Circuit Emulator
- PICMASTER®/PICMASTER-CE In-Circuit
Emulator
- ICEPIC™
• In-Circuit Debugger
- MPLAB-ICD for PIC16F877
• Device Programmers
- PRO MATE II Universal Programmer
- PICSTART Plus Entry-Level Prototype
Programmer
• Low-Cost Demonstration Boards
- SIMICE
- PICDEM-1
- PICDEM-2
- PICDEM-3
- PICDEM-17
- SEEVAL
- KEELOQ
16.1
•
•
•
•
•
•
MPLAB Integrated Development
Environment Software
- The MPLAB IDE software brings an ease of
software development previously unseen in
the 8-bit microcontroller market. MPLAB is a
Windows-based application which contains:
Multiple functionality
- editor
- simulator
- programmer (sold separately)
- emulator (sold separately)
A full featured editor
A project manager
Customizable tool bar and key mapping
A status bar
On-line help
 1999 Microchip Technology Inc.
• Edit your source files (either assembly or ‘C’)
• One touch assemble (or compile) and download
to PICmicro tools (automatically updates all
project information)
• Debug using:
- source files
- absolute listing file
- object code
The ability to use MPLAB with Microchip’s simulator,
MPLAB-SIM, allows a consistent platform and the ability to easily switch from the cost-effective simulator to
the full featured emulator with minimal retraining.
16.2
MPASM Assembler
MPASM is a full featured universal macro assembler for
all PICmicro MCU’s. It can produce absolute code
directly in the form of HEX files for device programmers, or it can generate relocatable objects for
MPLINK.
MPASM has a command line interface and a Windows
shell and can be used as a standalone application on a
Windows 3.x or greater system. MPASM generates
relocatable object files, Intel standard HEX files, MAP
files to detail memory usage and symbol reference, an
absolute LST file which contains source lines and generated machine code, and a COD file for MPLAB
debugging.
MPASM features include:
• MPASM and MPLINK are integrated into MPLAB
projects.
• MPASM allows user defined macros to be created
for streamlined assembly.
• MPASM allows conditional assembly for multi purpose source files.
• MPASM directives 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 and integrated development environments 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
DS40300B-page 125
PIC16F62X
16.4
MPLINK/MPLIB Linker/Librarian
MPLINK is a relocatable linker for MPASM and
MPLAB-C17 and MPLAB-C18. It can link relocatable
objects from assembly or C source files along with precompiled libraries using directives from a linker script.
MPLIB is a librarian for pre-compiled code to be used
with MPLINK. When a routine from a library is called
from another source file, only the modules that contains
that routine will be linked in with the application. This
allows large libraries to be used efficiently in many different applications. MPLIB manages the creation and
modification of library files.
MPLINK features include:
• MPLINK works with MPASM and MPLAB-C17
and MPLAB-C18.
• MPLINK allows all memory areas to be defined as
sections to provide link-time flexibility.
MPLIB features include:
• MPLIB makes linking easier because single libraries can be included instead of many smaller files.
• MPLIB helps keep code maintainable by grouping
related modules together.
• MPLIB commands allow libraries to be created
and modules to be added, listed, replaced,
deleted, or extracted.
16.5
MPLAB-SIM Software Simulator
The MPLAB-SIM Software Simulator allows code
development in a PC host environment by simulating
the PICmicro 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-SIM fully supports symbolic debugging using
MPLAB-C17 and MPLAB-C18 and MPASM. The Software Simulator offers the flexibility to develop and
debug code outside of the laboratory environment making it an excellent multi-project software development
tool.
16.6
MPLAB-ICE High Performance
Universal In-Circuit Emulator with
MPLAB IDE
The MPLAB-ICE Universal In-Circuit Emulator is
intended to provide the product development engineer
with a complete microcontroller design tool set for
PICmicro microcontrollers (MCUs). Software control of
MPLAB-ICE is provided by the MPLAB Integrated
Development Environment (IDE), which allows editing,
“make” and download, and source debugging from a
single environment.
DS40300B-page 126
Interchangeable processor modules allow the system
to be easily reconfigured for emulation of different processors. The universal architecture of the MPLAB-ICE
allows expansion to support new PICmicro microcontrollers.
The MPLAB-ICE 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
3.x/95/98 environment were chosen to best make these
features available to you, the end user.
MPLAB-ICE 2000 is a full-featured emulator system
with enhanced trace, trigger, and data monitoring features. Both systems use the same processor modules
and will operate across the full operating speed range
of the PICmicro MCU.
16.7
PICMASTER/PICMASTER CE
The PICMASTER system from Microchip Technology is
a full-featured, professional quality emulator system.
This flexible in-circuit emulator provides a high-quality,
universal platform for emulating Microchip 8-bit
PICmicro microcontrollers (MCUs). PICMASTER systems are sold worldwide, with a CE compliant model
available for European Union (EU) countries.
16.8
ICEPIC
ICEPIC is a low-cost in-circuit emulation solution for the
Microchip Technology PIC16C5X, PIC16C6X,
PIC16C7X, and PIC16CXXX families of 8-bit one-timeprogrammable (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.
16.9
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 PIC16F877 and can be used to
develop for this and other PICmicro microcontrollers
from the PIC16CXXX family. MPLAB-ICD utilizes the
In-Circuit Debugging capability built into the
PIC16F87X. This feature, along with Microchip’s In-Circuit Serial Programming protocol, offers cost-effective
in-circuit flash programming and 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. The
MPLAB-ICD is also a programmer for the flash
PIC16F87X family.
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
16.10
PRO MATE II Universal Programmer
The PRO MATE II Universal Programmer is a full-featured programmer capable of operating in stand-alone
mode as well as PC-hosted mode. PRO MATE II is CE
compliant.
The PRO MATE II has programmable VDD and VPP
supplies which allows 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 can read, verify or
program PICmicro devices. It can also set code-protect
bits in this mode.
16.11
PICSTART Plus Entry Level
Development System
The PICSTART programmer is an easy-to-use, lowcost prototype programmer. It connects to the PC via
one of the COM (RS-232) ports. MPLAB Integrated
Development Environment software makes using the
programmer simple and efficient.
PICSTART Plus supports all PICmicro devices with up
to 40 pins. Larger pin count devices such as the
PIC16C92X, and PIC17C76X may be supported with
an adapter socket. PICSTART Plus is CE compliant.
16.12
SIMICE Entry-Level
Hardware Simulator
SIMICE is an entry-level hardware development system designed to operate in a PC-based environment
with Microchip’s simulator MPLAB-SIM. Both SIMICE
and MPLAB-SIM run under Microchip Technology’s
MPLAB Integrated Development Environment (IDE)
software. Specifically, SIMICE provides hardware simulation for Microchip’s PIC12C5XX, PIC12CE5XX, and
PIC16C5X families of PICmicro 8-bit microcontrollers.
SIMICE works in conjunction with MPLAB-SIM to provide non-real-time I/O port emulation. SIMICE enables
a developer to run simulator code for driving the target
system. In addition, the target system can provide input
to the simulator code. This capability allows for simple
and interactive debugging without having to manually
generate MPLAB-SIM stimulus files. SIMICE is a valuable debugging tool for entry-level system development.
16.13
PICDEM-1 Low-Cost PICmicro
Demonstration Board
The PICDEM-1 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 users can
program the sample microcontrollers provided with
 1999 Microchip Technology Inc.
the PICDEM-1 board, on a PRO MATE II or
PICSTART-Plus programmer, and easily test firmware. The user can also connect the PICDEM-1
board to the MPLAB-ICE emulator and download the
firmware to the emulator for testing. Additional 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.
16.14
PICDEM-2 Low-Cost PIC16CXX
Demonstration Board
The PICDEM-2 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 board, on a PRO MATE II programmer or PICSTART-Plus, and easily test firmware.
The MPLAB-ICE emulator may also be used with the
PICDEM-2 board to test firmware. Additional 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 I2C bus and separate headers for connection to an LCD module and a keypad.
16.15
PICDEM-3 Low-Cost PIC16CXXX
Demonstration Board
The PICDEM-3 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 a 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 board, on a PRO MATE II programmer or PICSTART Plus with an adapter socket, and
easily test firmware. The MPLAB-ICE emulator may
also be used with the PICDEM-3 board to test firmware. Additional prototype area has been provided to
the user for adding hardware and connecting it to the
microcontroller socket(s). Some of the features include
an 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
board is an LCD panel, with 4 commons and 12 segments, that is capable of displaying time, temperature
and day of the week. The PICDEM-3 provides an additional RS-232 interface and Windows 3.1 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.
Preliminary
DS40300B-page 127
PIC16F62X
16.16
PICDEM-17
The PICDEM-17 is an evaluation board that demonstrates the capabilities of several Microchip microcontrollers,
including
PIC17C752,
PIC17C756,
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 or
PICSTART Plus device programmers and easily debug
and test the sample code. In addition, PICDEM-17 supports down-loading of programs to and executing out of
external FLASH memory on board. The PICDEM-17 is
also usable with the MPLAB-ICE or 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.
16.17
SEEVAL Evaluation and Programming
System
The SEEVAL SEEPROM Designer’s Kit supports all
Microchip 2-wire and 3-wire Serial EEPROMs. The kit
includes everything necessary to read, write, erase or
program special features of any Microchip SEEPROM
product including Smart Serials and secure serials.
The Total Endurance Disk is included to aid in tradeoff analysis and reliability calculations. The total kit can
significantly reduce time-to-market and result in an
optimized system.
16.18
K
EELOQ Evaluation and
Programming Tools
KEELOQ evaluation and programming tools support
Microchips HCS Secure Data Products. The HCS evaluation kit includes an LCD display to show changing
codes, a decoder to decode transmissions, and a programming interface to program test transmitters.
DS40300B-page 128
Preliminary
 1999 Microchip Technology Inc.
Software Tools
Emulators
 1999 Microchip Technology Inc.
Programmers Debugger
á
á
á
PIC16C5X
á
á á á á
á
á
PIC14000
á
á á á
á
á
PIC12CXXX
á
á á á á
á
á
PICSTARTPlus
Low-Cost Universal Dev. Kit
PRO MATE II
Universal Programmer
á á
á
á
PIC16C8X
á
á á á á
á
á
PIC16C7XX
á
á á á á
á
á
PIC16C7X
á
á á á á
á
á
PIC16F62X
á
á á
PIC16CXXX
á
á á á á
PIC16C6X
á
á á á á
á
á
á
Preliminary
á
á á
á
á
á
á
á
á á
á
á
á
á á
á
á
* 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.
†
á
MCP2510 CAN Developer’s Kit
PIC16F8XX
á
†
MCRFXXX
á á á
13.56 MHz Anticollision microID
Developer’s Kit
á
125 kHz Anticollision microID
Developer’s Kit
á
125 kHz microID Developer’s Kit
á á á á
microID™ Programmer’s Kit
PIC16C9XX
á
KEELOQ Transponder Kit
á
KEELOQ® Evaluation Kit
á
PICDEM-17
á á á
á
PICDEM-14A
PIC17C4X
á á
á
†
á
PICDEM-3
á
á á á
**
24CXX/
25CXX/
93CXX
á
PICDEM-2
á
**
á
PICDEM-1
á á á
*
PIC17C7XX
á á
**
HCSXXX
á
SIMICE
MPLAB-ICD In-Circuit Debugger
ICEPIC Low-Cost
In-Circuit Emulator
PICMASTER/PICMASTER-CE
MPLAB™-ICE
MPASM/MPLINK
MPLAB C18 Compiler
PIC18CXX2
á
*
á
MPLAB C17 Compiler
TABLE 16-1:
Demo Boards and Eval Kits
MPLAB Integrated
Development Environment
PIC16F62X
DEVELOPMENT TOOLS FROM MICROCHIP
MCP2510
á
DS40300B-page 129
PIC16F62X
NOTES:
DS40300B-page 130
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
17.0
ELECTRICAL SPECIFICATIONS
Absolute Maximum Ratings †
Ambient temperature under bias................................................................................................................. -40 to +125°C
Storage temperature .............................................................................................................................. -65°C to +150°C
Voltage on VDD with respect to VSS ........................................................................................................... -0.3 to +6.5V
Voltage on MCLR and RA4 with respect to VSS ..........................................................................................-0.3 to +14V
Voltage on all other pins with respect to VSS ....................................................................................-0.3V to VDD + 0.3V
Total power dissipation (Note 1)...........................................................................................................................800 mW
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....................................................................................................200 mA
Maximum current sourced by PORTA and PORTB ..............................................................................................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.
Note:
Voltage spikes below VSS at the MCLR pin, inducing currents greater than 80 mA, may cause latch-up.
Thus, a series resistor of 50-100Ω should be used when applying a "low" level to the MCLR pin rather
than pulling this pin directly to VSS.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 131
PIC16F62X
FIGURE 17-1: PIC16F62X VOLTAGE-FREQUENCY GRAPH, 0°C ≤ TA ≤ +70°C
6.0
5.5
5.0
VDD
(Volts)
4.5
4.0
3.5
3.0
2.5
0
4
10
20
25
Frequency (MHz)
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
FIGURE 17-2: PIC16F62X VOLTAGE-FREQUENCY GRAPH, -40°C ≤ TA < 0°C, +70°C < TA ≤ 85°C
6.0
5.5
5.0
VDD
(Volts)
4.5
4.0
3.5
3.0
2.5
2.0
0
4
10
20
25
Frequency (MHz)
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
DS40300B-page 132
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 17-3: PIC16LF62X VOLTAGE-FREQUENCY GRAPH, 0°C ≤ TA ≤ +70°C
6.0
5.5
5.0
4.5
VDD
(Volts)
4.0
3.5
3.0
2.5
2.0
0
4
10
20
25
Frequency (MHz)
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
FIGURE 17-4: PIC16LF62X VOLTAGE-FREQUENCY GRAPH, -40°C ≤ TA < 0°C, +70°C < TA ≤ 85°C
6.0
5.5
5.0
VDD
(Volts)
4.5
4.0
3.5
3.0
2.5
2.0
0
4
10
20
25
Frequency (MHz)
Note 1: The shaded region indicates the permissible combinations of voltage and frequency.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 133
PIC16F62X
17.1
DC CHARACTERISTICS:
Param
No.
PIC16F62X-04 (Commercial, Industrial, Extended)
PIC16F62X-20 (Commercial, Industrial, Extended)
Standard Operating Conditions (unless otherwise stated)
Operating temperature –40°C ≤ TA ≤ +85°C for industrial and
0°C ≤ TA ≤ +70°C for commercial and
–40°C ≤ TA ≤ +125°C for extended
Sym
Characteristic
Min Typ† Max Units
Conditions
D001
VDD
Supply Voltage
3.0
-
5.5
V
D002
VDR
RAM Data Retention
Voltage (Note 1)
–
1.5*
–
V
Device in SLEEP mode
D003
VPOR
VDD start voltage to
ensure Power-on Reset
–
Vss
–
V
See section on power-on reset for details
D004
SVDD
VDD rise rate to ensure
Power-on Reset
0.05*
–
–
V/ms
See section on power-on reset for details
D005
VBOD
Brown-out Detect Voltage
3.7
3.7
4.0
4.0
4.3
4.4
V
D010
IDD
Supply Current (Note 2, 5)
–
–
0.7
mA
FOSC = 4.0 MHZ, VDD = 3.0
–
–
–
4.0
–
–
7.0
6.0
2.0
mA
mA
mA
FOSC = 20.0 MHz, VDD = 5.5
FOSC = 20.0 MHz, VDD = 4.5
FOSC = 10.0 MHz, VDD = 3.0
D013
D020
IPD
Power Down Current (Note 3)
–
–
–
–
–
–
–
–
2.2
5.0
9.0
15.0
µA
µA
µA
µA
VDD = 3.0
VDD = 4.5
VDD = 5.5
VDD = 5.5 Extended
∆IWDT
WDT Current (Note 4)
–
6.0
–
–
75
30
20
25
125
50
µA
µA
µA
µA
VDD=4.0V
(125°C)
BOD enabled, VDD = 5.0V
VDD = 4.0V
135
µA
VDD = 4.0V
200
4
4
20
KHz
MHz
MHz
MHz
∆IBOD
Brown-out Detect Current (Note 4)
∆ICOMP Comparator Current for each
Comparator (Note 4)
∆IVREF VREF Current (Note 4)
D023
1A
FOSC
*
†
Note 1:
2:
3:
4:
5:
BODEN configuration bit is cleared
(Extended)
–
LP Oscillator Operating Frequency
INTRC Oscillator Operating Frequency
XT Oscillator Operating Frequency
HS Oscillator Operating Frequency
0
–
0
0
–
–
–
–
All temperatures
All temperatures
All temperatures
All temperatures
These parameters are characterized but not tested.
Data in "Typ" column is at 5.0V, 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 in SLEEP mode 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 tri-stated, 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 in hi-impedance state and tied to VDD or VSS.
The ∆ current is the additional current consumed when this peripheral is enabled. This current should be added to the
base IDD or IPD measurement.
For RC osc configuration, current through Rext is not included. The current through the resistor can be estimated by the
formula Ir = VDD/2Rext (mA) with Rext in kΩ.
DS40300B-page 134
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
17.2
DC CHARACTERISTICS:
Param
No.
PIC16LF62X-04 (Commercial, Industrial, Extended)
Standard Operating Conditions (unless otherwise stated)
Operating temperature –40°C ≤ TA ≤ +85°C for industrial and
0°C ≤ TA ≤ +70°C for commercial and
–40°C ≤ TA ≤ +125°C for extended
Operating voltage VDD range as described in DC spec Table 17.1 and Table 12-2
Sym
Characteristic
Min Typ† Max Units
Conditions
D001
VDD
Supply Voltage
2.0
-
5.5
V
D002
VDR
RAM Data Retention
Voltage (Note 1)
–
1.5*
–
V
Device in SLEEP mode
D003
VPOR
VDD start voltage to
ensure Power-on Reset
–
VSS
–
V
See section on Power-on Reset for
details
D004
SVDD
VDD rise rate to ensure
Power-on Reset
0.05*
–
–
V/ms
See section on Power-on Reset for
details
D005
VBOD
Brown-out Detect Voltage
3.7
4.0
4.3
V
D010
IDD
Supply Current (Note 2, 5)
–
–
0.6
mA
FOSC = 4.0 MHZ, VDD = 2.5
–
–
–
4.0
–
–
7.0
6.0
2.0
mA
mA
mA
FOSC = 20.0 MHz, VDD = 5.5
FOSC = 20.0 MHz, VDD = 4.5
FOSC = 10.0 MHz, VDD = 3.0
–
–
–
–
–
–
–
–
2.0
2.2
5.0
9.0
15.0
µA
µA
µA
µA
µA
VDD = 2.5
VDD = 3.0
VDD = 4.5
VDD = 5.5
VDD = 5.5 Extended
WDT Current (Note 4)
Brown-out Detect Current (Note 4)
Comparator Current for each
Comparator (Note 4)
VREF Current (Note 4)
–
–
6.0
75
15
125
µA
µA
VDD=3.0V
BOD enabled, VDD = 5.0V
–
–
30
50
135
µA
µA
VDD = 3.0V
VDD = 3.0V
LP Oscillator Operating Frequency
INTRC Oscillator Operating Frequency
XT Oscillator Operating Frequency
HS Oscillator Operating Frequency
0
–
0
0
–
–
–
–
200
4
4
20
KHz
MHz
MHz
MHz
D013
D020
IPD
D023
∆IWDT
∆IBOD
∆ICOMP
∆IVREF
1A
FOSC
*
†
Note 1:
2:
3:
4:
5:
Power Down Current (Note 2)
BODEN configuration bit is cleared
All temperatures
All temperatures
All temperatures
All temperatures
These parameters are characterized but not tested.
Data in "Typ" column is at 5.0V, 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 in SLEEP mode 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 tristated, 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 in hi-impedance state and tied to VDD to VSS.
The ∆ current is the additional current consumed when this peripheral is enabled. This current should be added to the base
IDD or IPD measurement.
For RC osc configuration, current through Rext is not included. The current through the resistor can be estimated by the formula Ir = VDD/2Rext (mA) with Rext in kΩ.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 135
PIC16F62X
17.3 DC CHARACTERISTICS: PIC16F62X (Commercial, Industrial, Extended)
PIC16LF62X (Commercial, Industrial, Extended)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
–40°C ≤ TA ≤ +85°C for industrial and
0°C ≤ TA ≤ +70°C for commercial and
–40°C ≤ TA ≤ +125°C for extended
Operating voltage VDD range as described in DC spec Table 17.1 and Table 12-2
Param.
No.
Sym
VIL
D030
D031
D032
D033
VIH
D040
D041
D042
D043
D043A
D070
D060
D061
D063
Characteristic
Input Low Voltage
I/O ports
with TTL buffer
with Schmitt Trigger input
MCLR, RA4/T0CKI,OSC1 (in ER
mode)
OSC1 (in XT and HS)
OSC1 (in LP)
Input High Voltage
I/O ports
with TTL buffer
with Schmitt Trigger input
MCLR RA4/T0CKI
OSC1 (XT, HS and LP)
OSC1 (in ER mode)
IPURB PORTB weak pull-up current
Input Leakage Current
IIL
(Notes 2, 3)
I/O ports (Except PORTA)
PORTA
RA4/T0CKI
OSC1, MCLR
D080
Output Low Voltage
I/O ports
D083
OSC2/CLKOUT (ER only)
VOL
D090
Output High Voltage (Note 3)
I/O ports (Except RA4)
D092
OSC2/CLKOUT (ER only)
VOH
Open-Drain High Voltage
Capacitive Loading Specs on
Output Pins
COSC2 OSC2 pin
*D150
VOD
D100
D101
*
†
Note 1:
2:
3:
Min
Typ†
Max
Unit
VSS
-
V
V SS
Vss
-
0.8V
0.15VDD
0.2VDD
0.2VDD
Vss
Vss
-
0.3VDD
0.6VDD-1.0
V
V
V
-
V
V
Conditions
VDD = 4.5V to 5.5V
otherwise
Note1
2.0V
.25VDD + 0.8V
0.8V DD
0.8VDD
0.7VDD
0.9VDD
50
-
VDD
VDD
VDD
VDD
VDD
200
400
Note1
µA VDD = 5.0V, VPIN = VSS
-
-
±1.0
±0.5
±1.0
±5.0
µA
µA
µA
µA
VSS ≤ VPIN ≤ VDD, pin at hi-impedance
Vss ≤ VPIN ≤ VDD, pin at hi-impedance
Vss ≤ VPIN ≤ VDD
Vss ≤ VPIN ≤ VDD, XT, HS and LP osc
configuration
-
-
0.6
0.6
0.6
0.6
V
V
V
V
IOL=8.5 mA, VDD=4.5V,
IOL=7.0 mA, VDD=4.5V,
IOL=1.6 mA, VDD=4.5V,
IOL=1.2 mA, VDD=4.5V,
VDD-0.7
VDD-0.7
VDD-0.7
VDD-0.7
-
8.5*
V
V
V
V
V
IOH=-3.0 mA, VDD=4.5V, -40° to +85°C
IOH=-2.5 mA, VDD=4.5V, +125°C
IOH=-1.3 mA, VDD=4.5V, -40° to +85°C
IOH=-1.0 mA, VDD=4.5V, +125°C
RA4 pin PIC16F62X, PIC16LF62X
-
15
VDD = 4.5V to 5.5V
otherwise
V
V
-40° to +85°C
+125°C
-40° to +85°C
+125°C
pF In XT, HS and LP modes when external
clock used to drive OSC1.
pF
Cio All I/O pins/OSC2 (in ER mode)
50
These parameters are characterized but not tested.
Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested.
In ER oscillator configuration, the OSC1 pin is a Schmitt Trigger input. It is not recommended that the PIC16F62X be driven with
external clock in ER mode.
The leakage current on the MCLR pin is strongly dependent on 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 coming out of the pin.
DS40300B-page 136
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
TABLE 17-1:
COMPARATOR SPECIFICATIONS
Operating Conditions: 3.0V < VDD <5.5V, -40°C < TA < +125°C, unless otherwise stated.
Param
No.
Characteristics
Sym
Min
Typ
Max
Units
D300
Input offset voltage
VIOFF
-
± 5.0
± 10
mV
D301
Input common mode voltage*
VICM
0
-
VDD - 1.5
V
D302
Common Mode Rejection Ratio* CMRR
300
300A
Response Time
301
Comparator Mode Change to
Output Valid*
(1)*
55
-
-
db
TRESP
-
150
400
600
ns
ns
TMC2OV
-
-
10
µs
Comments
16F62X
16LF62X
* These parameters are characterized but not tested.
Response time measured with one comparator input at (VDD - 1.5)/2 while the other input transitions from VSS to VDD.
TABLE 17-2:
VOLTAGE REFERENCE SPECIFICATIONS
Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +125°C, unless otherwise stated.
Spec
No.
Characteristics
Sym
Min
Typ
Max
Units
D310
Resolution
VRES
VDD/24
-
VDD/32
LSb
D311
Absolute Accuracy
VRAA
-
-
1/4
1/2
LSb
LSb
D312
Unit Resistor Value (R)*
VRUR
-
2k
-
Ω
TSET
-
-
10
µs
310
Settling Time
(1)*
Comments
Low Range (VRR = 1)
High Range (VRR = 0)
* These parameters are characterized but not tested.
Settling time measured while VRR = 1 and VR<3:0> transitions from 0000 to 1111.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 137
PIC16F62X
17.4
Timing Parameter Symbology
The timing parameter symbols have been created with one of the following formats:
1. TppS2ppS
2. TppS
T
F
Frequency
Lowercase subscripts (pp) and their meanings:
pp
ck
CLKOUT
io
I/O port
mc
MCLR
Uppercase letters and their meanings:
S
F
Fall
H
High
I
Invalid (Hi-impedance)
L
Low
T
Time
osc
t0
OSC1
T0CKI
P
R
V
Z
Period
Rise
Valid
Hi-Impedance
FIGURE 17-5: LOAD CONDITIONS
Load condition 2
Load condition 1
VDD/2
RL
CL
Pin
CL
Pin
VSS
VSS
RL = 464Ω
CL = 50 pF
15 pF
TABLE 17-3:
for all pins except OSC2
for OSC2 output
DC CHARACTERISTICS: PIC16F62X, PIC16LF62X
Standard Operating Conditions (unless otherwise stated)
DC Characteristics
Parameter
Sym
No.
Characteristic
Data EEPROM Memory
Endurance
VDD for read/write
D120
D121
Ed
Vdrw
D122
Tdew
D130
D131
Ep
Vpr
Erase/Write cycle time
Program Flash Memory
Endurance
VDD for read
D132
D133
Vpew
Tpew
VDD for erase/write
Erase/Write cycle time
*
†
Min
Typ†
Max
1M*
VMIN
10M
—
—
5.5
—
4
8*
1000*
Vmin
10000
—
—
5.5
4.5
—
—
4
5.5
8*
Units
Conditions
E/W 25°C at 5V
V VMIN = Minimum operating
voltage
ms
E/W
V VMIN = Minimum operating
voltage
V
ms
These parameters are characterized but not tested.
Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
DS40300B-page 138
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
17.5
Timing Diagrams and Specifications
FIGURE 17-6: EXTERNAL CLOCK TIMING
Q4
Q1
Q3
Q2
Q4
Q1
OSC1
1
3
3
4
4
2
CLKOUT
TABLE 17-4:
Parameter
No.
EXTERNAL CLOCK TIMING REQUIREMENTS
Sym
Fosc
Characteristic
Min
External CLKIN Frequency
(Note 1)
Oscillator Frequency
(Note 1)
1
2
3
4
5
Tosc
Tcy
TosL,
TosH
INTRC
ER
Units
Conditions
—
4
MHz
DC
DC
—
—
20
200
MHz
kHz
XT and ER osc mode,
VDD=5.0V
HS osc mode
LP osc mode
—
—
—
—
4
37
—
—
—
4
4
20
200
MHz
MHz
MHz
kHz
MHz
kHz
ns
ns
µs
ER osc mode, VDD=5.0V
XT osc mode
HS osc mode
LP osc mode
INTRC mode (fast)
INTRC mode (slow)
XT and ER osc mode
HS osc mode
LP osc mode
—
—
—
—
ns
10,000 ns
1,000 ns
µs
ns
µs
DC
ns
—
ns
External CLKIN Period
(Note 1)
250
50
5
Oscillator Period
(Note 1)
250
250
50
5
 1999 Microchip Technology Inc.
Max
DC
0.1
1
Instruction Cycle Time (Note 1)
External CLKIN (OSC1) High
External CLKIN Low
Internal Calibrated ER
External Biased ER Frequency
Typ†
1.0
100 *
3.65
10kHz
250
27
TCY
—
4.00
Preliminary
—
—
—
4.28
8MHz
MHz
ER osc mode
XT osc mode
HS osc mode
LP osc mode
INTRC mode (fast)
INTRC mode (slow)
TCY = 4/FOSC
XT oscillator, TOSC L/H duty
cycle
VDD = 5.0V
VDD = 5.0V
DS40300B-page 139
PIC16F62X
FIGURE 17-7: CLKOUT AND I/O TIMING
Q1
Q4
Q2
Q3
OSC1
11
10
22
CLKOUT
23
13
12
19
18
14
16
I/O Pin
(input)
15
17
I/O Pin
(output)
new value
old value
20, 21
TABLE 17-5:
Parameter
No.
10
CLKOUT AND I/O TIMING REQUIREMENTS
Sym
Characteristic
TosH2ckL
OSC1↑ to CLKOUT↓
TosH2ckH
OSC1↑ to CLKOUT↑
16F62X
10A
11
11A
12
TckR
CLKOUT rise time
12A
13
TckF
CLKOUT fall time
13A
Min
Typ†
Max
Units
—
75
200
ns
16LF62X
—
—
400
ns
16F62X
—
75
200
ns
16LF62X
—
—
400
ns
16F62X
—
35
100
ns
16LF62X
—
—
200
ns
16F62X
—
35
100
ns
16LF62X
—
—
200
ns
14
TckL2ioV
CLKOUT ↓ to Port out valid
—
—
20
ns
15
TioV2ckH
Port in valid before
16F62X
Tosc
+200
ns
—
—
ns
CLKOUT ↑
16LF62X
Tosc
=400
ns
—
—
ns
0
—
—
ns
16F62X
—
50
150 *
ns
16LF62X
—
—
300
ns
100
200
—
—
ns
16
TckH2ioI
17
TosH2ioV
Port in hold after CLKOUT ↑
OSC1↑ (Q1 cycle) to
Port out valid
18
TosH2ioI
DS40300B-page 140
OSC1↑ (Q2 cycle) to Port input invalid
(I/O in hold time)
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
FIGURE 17-8: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP
TIMER TIMING
VDD
MCLR
30
Internal
POR
33
PWRT
Timeout
32
OSC
Timeout
Internal
RESET
Watchdog
Timer
RESET
31
34
34
I/O Pins
FIGURE 17-9: BROWN-OUT DETECT TIMING
BVDD
VDD
35
TABLE 17-6:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP
TIMER REQUIREMENTS
Parameter
No.
Sym
30
TmcL
31
Twdt
Min
Typ†
Max
Unit
s
MCLR Pulse Width (low)
2000
TBD
—
TBD
—
TBD
ns
ms
VDD = 5V, -40°C to +85°C
Extended temperature
Watchdog Timer Time-out Period
(No Prescaler)
7
TBD
18
TBD
33
TBD
ms
ms
VDD = 5V, -40°C to +85°C
Extended temperature
Characteristic
32
Tost
33*
Tpwrt
Oscillation Start-up Timer Period
34
TIOZ
I/O Hi-impedance from MCLR Low
or Watchdog Timer Reset
35
TBOD
Brown-out Detect pulse width
Power up Timer Period
 1999 Microchip Technology Inc.
Conditions
—
1024TOSC
—
—
TOSC = OSC1 period
28
TBD
72
TBD
132
TBD
ms
ms
VDD = 5V, -40°C to +85°C
—
—
2.0
µs
100
—
—
µs
Preliminary
VDD ≤ BVDD (D005)
DS40300B-page 141
PIC16F62X
FIGURE 17-10: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
RA4/T0CKI
41
40
42
RB6/T1OSO/T1CKI
46
45
47
48
TMR0 or
TMR1
DS40300B-page 142
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
TABLE 17-7:
TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Sym
40*
Tt0H
T0CKI High Pulse Width
41*
Tt0L
T0CKI Low Pulse Width
42*
Tt0P
T0CKI Period
45*
Tt1H
T1CKI High
Time
46*
Tt1L
T1CKI Low
Time
47*
Tt1P
T1CKI input
period
Characteristic
Min
No Prescaler
With Prescaler
No Prescaler
With Prescaler
0.5TCY + 20
10
0.5TCY + 20
10
Greater of:
TCY + 40
N
0.5TCY + 20
15
25
30
50
0.5TCY + 20
15
25
30
50
Greater of:
TCY + 40
N
Greater of:
TCY + 40
N
60
100
DC
Synchronous, No Prescaler
Synchronous, 16F62X
with Prescaler 16LF62X
Asynchronous 16F62X
16LF62X
Synchronous, No Prescaler
Synchronous, 16F62X
with Prescaler 16LF62X
Asynchronous 16F62X
16LF62X
Synchronous 16F62X
16LF62X
Typ† Max Units
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Conditions
ns
ns
ns
ns
ns N = prescale
value (2, 4, ...,
256)
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns N = prescale
value (1, 2, 4, 8)
—
Asynchronous 16F62X
—
—
ns
16LF62X
—
—
ns
Ft1
Timer1 oscillator input frequency range
— 200 kHz
(oscillator enabled by setting bit T1OSCEN)
48
TCKEZtmr1 Delay from external clock edge to timer
2Tosc
— 7Tos —
increment
c
* 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 17-11: CAPTURE/COMPARE/PWM TIMINGS
RB3/CCP1
(Capture Mode)
50
51
52
RB3/CCP1
(Compare or PWM Mode)
53
 1999 Microchip Technology Inc.
54
Preliminary
DS40300B-page 143
PIC16F62X
TABLE 17-8:
CAPTURE/COMPARE/PWM REQUIREMENTS
Param
Sym
No.
50*
51*
Characteristic
TccL CCP
input low time
TccH CCP
input high time
Min
No Prescaler
0.5TCY + 20
—
—
ns
10
—
—
ns
16F62X
With Prescaler 16LF62X
20
—
—
ns
0.5TCY + 20
—
—
ns
10
—
—
ns
20
—
—
ns
3TCY + 40
N
—
—
ns
16F62X
10
25
ns
16LF62X
25
45
ns
16F62X
10
25
ns
16LF62X
25
45
ns
No Prescaler
16F62X
With Prescaler 16LF62X
52*
TccP CCP input period
53*
TccR CCP output rise time
54*
TccF CCP output fall time
Typ† Max Units
Conditions
N = prescale
value (1,4 or
16)
* 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 17-12: TIMER0 CLOCK TIMING
RA4/T0CKI
41
40
42
TMR0
TABLE 17-9:
Parameter
No.
40
TIMER0 CLOCK REQUIREMENTS
Sym Characteristic
Tt0H T0CKI High Pulse Width
No Prescaler
Min
Typ†
Max
0.5 TCY + 20*
—
—
ns
10*
—
—
ns
0.5 TCY + 20*
—
—
ns
With Prescaler
41
Tt0L T0CKI Low Pulse Width
42
Tt0P T0CKI Period
No Prescaler
With Prescaler
*
†
Units Conditions
10*
—
—
ns
TCY + 40*
N
—
—
ns
N = prescale value
(1, 2, 4, ..., 256)
These parameters are characterized but not tested.
Data in "Typ" column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.
DS40300B-page 144
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
18.0
DEVICE CHARACTERIZATION
INFORMATION
Not Available at this time.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 145
PIC16F62X
NOTES:
DS40300B-page 146
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
19.0
PACKAGING INFORMATION
19.1
Package Marking Information
18-Lead PDIP
Example
XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXX
AABBCDE
18-Lead SOIC (.300")
XXXXXXXXXXXX
XXXXXXXXXXXX
XXXXXXXXXXXX
AABBCDE
20-Lead SSOP
XXXXXXXXXX
XXXXXXXXXX
AABBCDE
Legend: MM...M
XX...X
AA
BB
C
D
E
Note:
*
PIC16F627
-04I / P456
9923 CBA
Example
PIC16F627
-04I / S0218
9918 CDK
Example
PIC16F627
-04I / 218
9951 CBP
Microchip part number information
Customer specific information*
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Facility code of the plant at which wafer is manufactured
O = Outside Vendor
C = 5” Line
S = 6” Line
H = 8” Line
Mask revision number
Assembly code of the plant or country of origin in which
part was assembled
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.
Standard OTP marking consists of Microchip part number, year code, week code, facility code, mask
rev#, and assembly code. For OTP marking beyond this, certain price adders apply. Please check with
your Microchip Sales Office. For QTP devices, any special marking adders are included in QTP price.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 147
PIC16F62X
Package Type:
K04-007 18-Lead Plastic Dual In-line (P) – 300 mil
E
D
2
n
α
1
E1
A1
A
R
L
c
A2
B1
β
p
B
eB
Units
Dimension Limits
PCB Row Spacing
Number of Pins
Pitch
Lower Lead Width
Upper Lead Width
Shoulder Radius
Lead Thickness
Top to Seating Plane
Top of Lead to Seating Plane
Base to Seating Plane
Tip to Seating Plane
Package Length
Molded Package Width
Radius to Radius Width
Overall Row Spacing
Mold Draft Angle Top
Mold Draft Angle Bottom
INCHES*
NOM
0.300
18
0.100
0.013
0.018
0.055
0.060
0.000
0.005
0.005
0.010
0.110
0.155
0.075
0.095
0.000
0.020
0.125
0.130
0.890
0.895
0.245
0.255
0.230
0.250
0.310
0.349
5
10
5
10
MIN
n
p
B
B1†
R
c
A
A1
A2
L
D‡
E‡
E1
eB
α
β
MAX
0.023
0.065
0.010
0.015
0.155
0.115
0.020
0.135
0.900
0.265
0.270
0.387
15
15
MILLIMETERS
NOM
7.62
18
2.54
0.33
0.46
1.40
1.52
0.00
0.13
0.13
0.25
2.79
3.94
1.91
2.41
0.00
0.51
3.18
3.30
22.61
22.73
6.22
6.48
5.84
6.35
7.87
8.85
5
10
5
10
MIN
MAX
0.58
1.65
0.25
0.38
3.94
2.92
0.51
3.43
22.86
6.73
6.86
9.83
15
15
* Controlling Parameter.
†
Dimension “B1” does not include dam-bar protrusions. Dam-bar protrusions shall not exceed 0.003”
(0.076 mm) per side or 0.006” (0.152 mm) more than dimension “B1.”
‡
Dimensions “D” and “E” do not include mold flash or protrusions. Mold flash or protrusions shall not
exceed 0.010” (0.254 mm) per side or 0.020” (0.508 mm) more than dimensions “D” or “E.”
DS40300B-page 148
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
Package Type:
K04-051 18-Lead Plastic Small Outline (SO) – Wide, 300 mil
E1
p
E
D
2
B
1
n
X
45 °
α
L
R2
c
A
R1
β
Units
Dimension Limits
Pitch
Number of Pins
Overall Pack. Height
Shoulder Height
Standoff
Molded Package Length
Molded Package Width
Outside Dimension
Chamfer Distance
Shoulder Radius
Gull Wing Radius
Foot Length
Foot Angle
Radius Centerline
Lead Thickness
Lower Lead Width
Mold Draft Angle Top
Mold Draft Angle Bottom
L1
φ
A2
INCHES*
NOM
0.050
18
0.093
0.099
0.048
0.058
0.004
0.008
0.450
0.456
0.292
0.296
0.394
0.407
0.010
0.020
0.005
0.005
0.005
0.005
0.011
0.016
0
4
0.010
0.015
0.009
0.011
0.014
0.017
0
12
0
12
MIN
p
n
A
A1
A2
D‡
E‡
E1
X
R1
R2
L
φ
L1
c
B†
α
β
A1
MAX
0.104
0.068
0.011
0.462
0.299
0.419
0.029
0.010
0.010
0.021
8
0.020
0.012
0.019
15
15
MILLIMETERS
NOM
MAX
1.27
18
2.64
2.36
2.50
1.73
1.22
1.47
0.28
0.10
0.19
11.73
11.43
11.58
7.59
7.42
7.51
10.64
10.01
10.33
0.74
0.25
0.50
0.25
0.13
0.13
0.25
0.13
0.13
0.53
0.28
0.41
4
8
0
0.51
0.25
0.38
0.30
0.23
0.27
0.48
0.36
0.42
0
12
15
0
12
15
MIN
*
Controlling Parameter.
†
Dimension “B” does not include dam-bar protrusions. Dam-bar protrusions shall not exceed 0.003”
(0.076 mm) per side or 0.006” (0.152 mm) more than dimension “B.”
‡
Dimensions “D” and “E” do not include mold flash or protrusions. Mold flash or protrusions shall not
exceed 0.010” (0.254 mm) per side or 0.020” (0.508 mm) more than dimensions “D” or “E.”
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 149
PIC16F62X
Package Type:
K04-072 20-Lead Plastic Shrink Small Outline (SS) – 5.30 mm
E1
E
p
D
B
2
1
n
α
L
R2
c
A
A1
R1
φ
L1
A2
β
Units
Dimension Limits
Pitch
Number of Pins
Overall Pack. Height
Shoulder Height
Standoff
Molded Package Length
Molded Package Width
Outside Dimension
Shoulder Radius
Gull Wing Radius
Foot Length
Foot Angle
Radius Centerline
Lead Thickness
Lower Lead Width
Mold Draft Angle Top
Mold Draft Angle Bottom
INCHES
NOM
0.026
20
0.068
0.073
0.026
0.036
0.002
0.005
0.278
0.283
0.205
0.208
0.301
0.306
0.005
0.005
0.005
0.005
0.015
0.020
4
0
0.000
0.005
0.005
0.007
0.010
0.012
0
5
0
5
MIN
p
n
A
A1
A2
D‡
E‡
E1
R1
R2
L
φ
L1
c
B†
α
β
MAX
0.078
0.046
0.008
0.289
0.212
0.311
0.010
0.010
0.025
8
0.010
0.009
0.015
10
10
MILLIMETERS*
NOM
MAX
0.65
20
1.86
1.99
1.73
0.91
1.17
0.66
0.13
0.21
0.05
7.20
7.33
7.07
5.29
5.38
5.20
7.78
7.90
7.65
0.13
0.25
0.13
0.13
0.25
0.13
0.51
0.64
0.38
4
0
8
0.13
0.25
0.00
0.18
0.22
0.13
0.32
0.38
0.25
0
5
10
0
5
10
MIN
*
Controlling Parameter.
†
Dimension “B” does not include dam-bar protrusions. Dam-bar protrusions shall not exceed 0.003”
(0.076 mm) per side or 0.006” (0.152 mm) more than dimension “B.”
‡
Dimensions “D” and “E” do not include mold flash or protrusions. Mold flash or protrusions shall not
exceed 0.010” (0.254 mm) per side or 0.020” (0.508 mm) more than dimensions “D” or “E.”
DS40300B-page 150
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
INDEX
A
A/D
Special Event Trigger (CCP)....................................... 65
Absolute Maximum Ratings .............................................. 131
ADDLW Instruction ........................................................... 115
ADDWF Instruction ........................................................... 115
ANDLW Instruction ........................................................... 115
ANDWF Instruction ........................................................... 115
Architectural Overview .......................................................... 9
Assembler
MPASM Assembler................................................... 125
B
Baud Rate Error .................................................................. 73
Baud Rate Formula ............................................................. 73
Baud Rates
Asynchronous Mode ................................................... 74
Synchronous Mode ..................................................... 74
BCF Instruction ................................................................. 116
Block Diagram
TIMER0....................................................................... 45
TMR0/WDT PRESCALER .......................................... 48
Block Diagrams
Comparator I/O Operating Modes............................... 58
Comparator Output ..................................................... 60
RA3:RA0 and RA5 Port Pins ...................................... 35
Timer1......................................................................... 51
Timer2......................................................................... 54
USART Receive.......................................................... 80
USART Transmit......................................................... 78
BRGH bit ............................................................................. 73
Brown-Out Detect (BOD) .................................................. 101
BSF Instruction ................................................................. 116
BTFSC Instruction............................................................. 116
BTFSS Instruction ............................................................. 117
C
CALL Instruction ............................................................... 117
Capture (CCP Module) ....................................................... 64
Block Diagram............................................................. 64
CCP Pin Configuration................................................ 64
CCPR1H:CCPR1L Registers...................................... 64
Changing Between Capture Prescalers...................... 64
Software Interrupt ....................................................... 64
Timer1 Mode Selection ............................................... 64
Capture/Compare/PWM (CCP)........................................... 63
CCP1 .......................................................................... 63
CCP1CON Register ............................................ 63
CCPR1H Register............................................... 63
CCPR1L Register ............................................... 63
CCP2 .......................................................................... 63
Timer Resources......................................................... 63
CCP1CON Register ............................................................ 63
CCP1M3:CCP1M0 Bits............................................... 63
CCP1X:CCP1Y Bits .................................................... 63
CCP2CON Register
CCP2M3:CCP2M0 Bits............................................... 63
CCP2X:CCP2Y Bits .................................................... 63
Clocking Scheme/Instruction Cycle .................................... 12
CLRF Instruction ............................................................... 117
CLRW Instruction .............................................................. 117
CLRWDT Instruction ......................................................... 118
CMCON Register ................................................................ 57
Code Protection ................................................................ 112
COMF Instruction .............................................................. 118
Comparator Configuration................................................... 58
 1999 Microchip Technology Inc.
Comparator Interrupts......................................................... 61
Comparator Module ............................................................ 57
Comparator Operation ........................................................ 59
Comparator Reference ....................................................... 59
Compare (CCP Module) ..................................................... 65
Block Diagram ............................................................ 65
CCP Pin Configuration ............................................... 65
CCPR1H:CCPR1L Registers ..................................... 65
Software Interrupt ....................................................... 65
Special Event Trigger ................................................. 65
Timer1 Mode Selection............................................... 65
Configuration Bits ............................................................... 96
Configuring the Voltage Reference..................................... 69
Crystal Operation................................................................ 97
D
DATA .................................................................................. 93
Data .................................................................................... 93
Data EEPROM Memory...................................................... 91
EECON1 Register ...................................................... 91
EECON2 Register ...................................................... 91
Data Memory Organization................................................. 13
DECF Instruction .............................................................. 118
DECFSZ Instruction.......................................................... 118
Development Support ....................................................... 125
E
EECON1 ............................................................................. 92
Errata .................................................................................... 3
External Crystal Oscillator Circuit ....................................... 98
G
General purpose Register File............................................ 13
GOTO Instruction.............................................................. 119
I
I/O Ports ............................................................................. 27
I/O Programming Considerations ....................................... 44
ID Locations...................................................................... 112
INCF Instruction................................................................ 119
INCFSZ Instruction ........................................................... 119
In-Circuit Serial Programming........................................... 112
Indirect Addressing, INDF and FSR Registers ................... 26
Instruction Flow/Pipelining .................................................. 12
Instruction Set
ADDLW..................................................................... 115
ADDWF .................................................................... 115
ANDLW..................................................................... 115
ANDWF .................................................................... 115
BCF .......................................................................... 116
BSF........................................................................... 116
BTFSC...................................................................... 116
BTFSS ...................................................................... 117
CALL......................................................................... 117
CLRF ........................................................................ 117
CLRW ....................................................................... 117
CLRWDT .................................................................. 118
COMF ....................................................................... 118
DECF........................................................................ 118
DECFSZ ................................................................... 118
GOTO ....................................................................... 119
INCF ......................................................................... 119
INCFSZ..................................................................... 119
IORLW ...................................................................... 119
IORWF...................................................................... 120
MOVF ....................................................................... 120
MOVLW .................................................................... 120
MOVWF.................................................................... 120
Preliminary
DS40300B-page 151
PIC16F62X
NOP .......................................................................... 121
OPTION .................................................................... 121
RETFIE ..................................................................... 121
RETLW ..................................................................... 121
RETURN ................................................................... 122
RLF ........................................................................... 122
RRF........................................................................... 122
SLEEP ...................................................................... 122
SUBLW ..................................................................... 123
SUBWF ..................................................................... 123
SWAPF ..................................................................... 124
TRIS .......................................................................... 124
XORLW ..................................................................... 124
XORWF..................................................................... 124
Instruction Set Summary................................................... 113
INT Interrupt ...................................................................... 108
INTCON Register ................................................................ 21
Interrupt Sources
Capture Complete (CCP) ............................................ 64
Compare Complete (CCP) .......................................... 65
TMR2 to PR2 Match (PWM) ....................................... 66
Interrupts ........................................................................... 107
Interrupts, Enable Bits
CCP1 Enable (CCP1IE Bit)......................................... 64
Interrupts, Flag Bits
CCP1 Flag (CCP1IF Bit) ....................................... 64, 65
IORLW Instruction............................................................. 119
IORWF Instruction............................................................. 120
Power-Down Mode (SLEEP) ............................................ 111
Power-On Reset (POR) .................................................... 101
Power-up Timer (PWRT) .................................................. 101
PR2 Register ...................................................................... 54
Prescaler............................................................................. 48
Prescaler, Capture.............................................................. 64
Prescaler, Timer2 ............................................................... 66
PRO MATE II Universal Programmer ............................ 127
Program Memory Organization........................................... 13
PROTECTION .................................................................... 93
PWM (CCP Module) ........................................................... 66
Block Diagram ............................................................ 66
CCPR1H:CCPR1L Registers...................................... 66
Duty Cycle .................................................................. 66
Example Frequencies/Resolutions ............................. 67
Output Diagram .......................................................... 66
Period ......................................................................... 66
Set-Up for PWM Operation......................................... 67
TMR2 to PR2 Match ................................................... 66
Q
Q-Clock............................................................................... 66
Quick-Turnaround-Production (QTP) Devices...................... 7
R
Memory Organization
Data EEPROM Memory .............................................. 91
MOVF Instruction .............................................................. 120
MOVLW Instruction ........................................................... 120
MOVWF Instruction........................................................... 120
MPLAB Integrated Development Environment Software .. 125
RC Oscillator....................................................................... 98
READING ........................................................................... 93
Registers
Maps
PIC16C76 ........................................................... 14
PIC16C77 ........................................................... 14
RCSTA
Diagram .............................................................. 72
Reset .................................................................................. 99
RETFIE Instruction ........................................................... 121
RETLW Instruction............................................................ 121
RETURN Instruction ......................................................... 122
RLF Instruction ................................................................. 122
RRF Instruction................................................................. 122
N
S
NOP Instruction................................................................. 121
SEEVAL Evaluation and Programming System............. 128
Serialized Quick-Turnaround-Production
(SQTP) Devices.................................................................... 7
SLEEP Instruction............................................................. 122
Software Simulator (MPLAB-SIM) .................................... 126
Special ................................................................................ 99
Special Features of the CPU .............................................. 95
Special Function Registers ................................................. 15
Stack................................................................................... 25
Status Register ................................................................... 19
SUBLW Instruction ........................................................... 123
SUBWF Instruction ........................................................... 123
SWAPF Instruction ........................................................... 124
K
KeeLoq Evaluation and Programming Tools.................. 128
M
O
OPTION Instruction........................................................... 121
OPTION Register ................................................................ 20
Oscillator Configurations ..................................................... 97
Oscillator Start-up Timer (OST) ........................................ 101
Output of TMR2................................................................... 54
P
Package Marking Information ........................................... 147
Packaging Information ...................................................... 147
PCL and PCLATH ............................................................... 25
PCON Register ................................................................... 24
PICDEM-1 Low-Cost PICmicro Demo Board.................... 127
PICDEM-2 Low-Cost PIC16CXX Demo Board ................. 127
PICDEM-3 Low-Cost PIC16CXXX Demo Board............... 127
PICSTART Plus Entry Level Development System ....... 127
PIE1 Register ...................................................................... 22
Pin Functions
RC6/TX/CK ........................................................... 71–88
RC7/RX/DT ........................................................... 71–88
Pinout Description ............................................................... 11
PIR1 Register...................................................................... 23
Port RB Interrupt ............................................................... 108
PORTA................................................................................ 27
PORTB................................................................................ 34
Power Control/Status Register (PCON) ............................ 102
DS40300B-page 152
T
T1CKPS0 bit ....................................................................... 50
T1CKPS1 bit ....................................................................... 50
T1CON Register ................................................................. 50
T1OSCEN bit ...................................................................... 50
T1SYNC bit......................................................................... 50
T2CKPS0 bit ....................................................................... 55
T2CKPS1 bit ....................................................................... 55
T2CON Register ................................................................. 55
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
Timer0
TIMER0....................................................................... 45
TIMER0 (TMR0) Interrupt ........................................... 45
TIMER0 (TMR0) Module............................................. 45
TMR0 with External Clock........................................... 47
Timer1
Special Event Trigger (CCP)....................................... 65
Switching Prescaler Assignment................................. 49
Timer2
PR2 Register............................................................... 66
TMR2 to PR2 Match Interrupt ..................................... 66
Timers
Timer1
Asynchronous Counter Mode ............................. 52
Block Diagram .................................................... 51
Capacitor Selection............................................. 52
External Clock Input............................................ 51
External Clock Input Timing ................................ 52
Operation in Timer Mode .................................... 51
Oscillator ............................................................. 52
Prescaler....................................................... 51, 53
Resetting of Timer1 Registers ............................ 53
Resetting Timer1 using a CCP Trigger Output ... 53
Synchronized Counter Mode .............................. 51
T1CON................................................................ 50
TMR1H ............................................................... 52
TMR1L ................................................................ 52
Timer2
Block Diagram .................................................... 54
Module ................................................................ 54
Postscaler ........................................................... 54
Prescaler............................................................. 54
T2CON................................................................ 55
Timing Diagrams
Timer0....................................................................... 142
Timer1....................................................................... 142
USART Asynchronous Master Transmission.............. 79
USART RX Pin Sampling...................................... 76, 77
USART Synchronous Reception................................. 87
USART Synchronous Transmission ........................... 85
USART, Asynchronous Reception.............................. 81
Timing Diagrams and Specifications................................. 139
TMR0 Interrupt .................................................................. 108
TMR1CS bit ........................................................................ 50
TMR1ON bit ........................................................................ 50
TMR2ON bit ........................................................................ 55
TOUTPS0 bit....................................................................... 55
TOUTPS1 bit....................................................................... 55
TOUTPS2 bit....................................................................... 55
TOUTPS3 bit....................................................................... 55
TRIS Instruction ................................................................ 124
TRISA ................................................................................. 27
TRISB ................................................................................. 34
TXSTA Register .................................................................. 71
USART
Asynchronous Mode................................................... 78
Asynchronous Receiver.............................................. 80
Asynchronous Reception............................................ 82
Asynchronous Transmission ...................................... 79
Asynchronous Transmitter.......................................... 78
Baud Rate Generator (BRG) ...................................... 73
Sampling..................................................................... 76
Synchronous Master Mode......................................... 84
Synchronous Master Reception ................................. 86
Synchronous Master Transmission ............................ 84
Synchronous Slave Mode........................................... 88
Synchronous Slave Reception ................................... 88
Synchronous Slave Transmit...................................... 88
Transmit Block Diagram ............................................. 78
V
Voltage Reference Module ................................................. 69
VRCON Register ................................................................ 69
W
Watchdog Timer (WDT).................................................... 109
WRITE ................................................................................ 93
WRITING ............................................................................ 93
WWW, On-Line Support ....................................................... 3
X
XORLW Instruction ........................................................... 124
XORWF Instruction........................................................... 124
U
Universal Synchronous Asynchronous Receiver
Transmitter (USART) .......................................................... 71
Asynchronous Receiver
Setting Up Reception .......................................... 83
Timing Diagram .................................................. 81
Asynchronous Receiver Mode
Block Diagram .................................................... 83
Section ................................................................ 83
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 153
PIC16F62X
DS40300B-page 154
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
ON-LINE SUPPORT
Systems Information and Upgrade Hot Line
Microchip provides on-line support on the Microchip
World Wide Web (WWW) site.
The web site is used by Microchip as a means to make
files and information easily available to customers. To
view the site, the user must have access to the Internet
and a web browser, such as Netscape or Microsoft
Explorer. Files are also available for FTP download
from our FTP site.
The Systems Information and Upgrade Line provides
system users a listing of the latest versions of all of
Microchip’s development systems software products.
Plus, this line provides information on how customers
can receive any currently available upgrade kits.The
Hot Line Numbers are:
1-800-755-2345 for U.S. and most of Canada, and
1-602-786-7302 for the rest of the world.
Connecting to the Microchip Internet Web Site
981103
The Microchip web site is available by using your
favorite Internet browser to attach to:
www.microchip.com
The file transfer site is available by using an FTP service to connect to:
ftp://ftp.microchip.com
The web site and file transfer site provide a variety of
services. Users may download files for the latest
Development Tools, Data Sheets, Application Notes,
User’s Guides, Articles and Sample Programs. A variety of Microchip specific business information is also
available, including listings of Microchip sales offices,
distributors and factory representatives. Other data
available for consideration is:
• Latest Microchip Press Releases
• Technical Support Section with Frequently Asked
Questions
• Design Tips
• Device Errata
• Job Postings
• Microchip Consultant Program Member Listing
• Links to other useful web sites related to
Microchip Products
• Conferences for products, Development Systems, technical information and more
• Listing of seminars and events
 1999 Microchip Technology Inc.
Trademarks: The Microchip name, logo, PIC, PICmicro,
PICSTART, PICMASTER and PRO MATE are registered
trademarks of Microchip Technology Incorporated in the
U.S.A. and other countries. FlexROM, MPLAB and fuzzyLAB are trademarks and SQTP is a service mark of Microchip in the U.S.A.
All other trademarks mentioned herein are the property of
their respective companies.
Preliminary
DS40300B-page 155
PIC16F62X
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 (602) 786-7578.
Please list the following information, and use this outline to provide us with your comments about this Data Sheet.
To:
Technical Publications Manager
RE:
Reader Response
Total Pages Sent
From: Name
Company
Address
City / State / ZIP / Country
Telephone: (_______) _________ - _________
FAX: (______) _________ - _________
Application (optional):
Would you like a reply?
Device: PIC16F62X
Y
N
Literature Number: DS40300B
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 data sheet easy to follow? If not, why?
4. What additions to the data sheet do you think would enhance the structure and subject?
5. What deletions from the data sheet 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?
8. How would you improve our software, systems, and silicon products?
DS40300B-page 156
Preliminary
 1999 Microchip Technology Inc.
PIC16F62X
PIC16F62X PRODUCT IDENTIFICATION SYSTEM
To order or to obtain information, e.g., on pricing or delivery, please use the listed part numbers, and refer to the factory or the listed
sales offices.
PART NO.
-XX
X /XX XXX
Pattern:
3-Digit Pattern Code for QTP (blank otherwise)
Package:
P
SO
SS
=
=
=
PDIP
SOIC (Gull Wing, 300 mil body)
SSOP (209 mil)
Temperature Range:
I
E
=
=
=
0°C to +70°C
–40°C to +85°C
–40°C to +125°C
Frequency
Range:
04
04
20
=
=
=
200kHz (LP osc)
4 MHz (XT and ER osc)
20 MHz (HS osc)
Device:
PIC16F62X :VDD range 3.0V to 5.5V
PIC16F62XT:VDD range 3.0V to 5.5V (Tape and Reel)
PIC16LF62X:VDD range 2.0V to 5.5V
PIC16LF62XT:VDD range 2.0V to 5.5V (Tape and Reel)
Examples:
g) PIC16F627 - 04/P 301 =
Commercial temp., PDIP package, 4 MHz, normal VDD limits,
QTP pattern #301.
h) PIC16LF627- 04I/SO =
Industrial temp., SOIC package, 200kHz, extended VDD
limits.
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.
3.
Your local Microchip sales office
The Microchip Corporate Literature Center U.S. FAX: (602) 786-7277
The Microchip Worldwide Site (www.microchip.com)
Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using.
New Customer Notification System
Register on our web site (www.microchip.com/cn) to receive the most current information on our products.
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 157
PIC16F62X
NOTES:
DS40300B-page 158
 1999 Microchip Technology Inc.
PIC16F62X
NOTES:
 1999 Microchip Technology Inc.
Preliminary
DS40300B-page 159
WORLDWIDE SALES AND SERVICE
AMERICAS
AMERICAS (continued)
Corporate Office
Toronto
Singapore
Microchip Technology Inc.
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-786-7200 Fax: 480-786-7277
Technical Support: 480-786-7627
Web Address: http://www.microchip.com
Microchip Technology Inc.
5925 Airport Road, Suite 200
Mississauga, Ontario L4V 1W1, Canada
Tel: 905-405-6279 Fax: 905-405-6253
Microchip Technology Singapore Pte Ltd.
200 Middle Road
#07-02 Prime Centre
Singapore 188980
Tel: 65-334-8870 Fax: 65-334-8850
Atlanta
Microchip Asia Pacific
Unit 2101, Tower 2
Metroplaza
223 Hing Fong Road
Kwai Fong, N.T., Hong Kong
Tel: 852-2-401-1200 Fax: 852-2-401-3431
Microchip Technology Inc.
500 Sugar Mill Road, Suite 200B
Atlanta, GA 30350
Tel: 770-640-0034 Fax: 770-640-0307
Boston
Microchip Technology Inc.
5 Mount Royal Avenue
Marlborough, MA 01752
Tel: 508-480-9990 Fax: 508-480-8575
Chicago
Microchip Technology Inc.
333 Pierce Road, Suite 180
Itasca, IL 60143
Tel: 630-285-0071 Fax: 630-285-0075
Dallas
Microchip Technology Inc.
4570 Westgrove Drive, Suite 160
Addison, TX 75248
Tel: 972-818-7423 Fax: 972-818-2924
Dayton
Microchip Technology Inc.
Two Prestige Place, Suite 150
Miamisburg, OH 45342
Tel: 937-291-1654 Fax: 937-291-9175
Detroit
Microchip Technology Inc.
Tri-Atria Office Building
32255 Northwestern Highway, Suite 190
Farmington Hills, MI 48334
Tel: 248-538-2250 Fax: 248-538-2260
Los Angeles
Microchip Technology Inc.
18201 Von Karman, Suite 1090
Irvine, CA 92612
Tel: 949-263-1888 Fax: 949-263-1338
New York
Microchip Technology Inc.
150 Motor Parkway, Suite 202
Hauppauge, NY 11788
Tel: 631-273-5305 Fax: 631-273-5335
San Jose
Microchip Technology Inc.
2107 North First Street, Suite 590
San Jose, CA 95131
Tel: 408-436-7950 Fax: 408-436-7955
ASIA/PACIFIC
Hong Kong
ASIA/PACIFIC (continued)
Taiwan, R.O.C
Microchip Technology Taiwan
10F-1C 207
Tung Hua North Road
Taipei, Taiwan, ROC
Tel: 886-2-2717-7175 Fax: 886-2-2545-0139
EUROPE
Beijing
United Kingdom
Microchip Technology, Beijing
Unit 915, 6 Chaoyangmen Bei Dajie
Dong Erhuan Road, Dongcheng District
New China Hong Kong Manhattan Building
Beijing 100027 PRC
Tel: 86-10-85282100 Fax: 86-10-85282104
Arizona Microchip Technology Ltd.
505 Eskdale Road
Winnersh Triangle
Wokingham
Berkshire, England RG41 5TU
Tel: 44 118 921 5858 Fax: 44-118 921-5835
India
Denmark
Microchip Technology Inc.
India Liaison Office
No. 6, Legacy, Convent Road
Bangalore 560 025, India
Tel: 91-80-229-0061 Fax: 91-80-229-0062
Microchip Technology Denmark ApS
Regus Business Centre
Lautrup hoj 1-3
Ballerup DK-2750 Denmark
Tel: 45 4420 9895 Fax: 45 4420 9910
Japan
France
Microchip Technology Intl. Inc.
Benex S-1 6F
3-18-20, Shinyokohama
Kohoku-Ku, Yokohama-shi
Kanagawa 222-0033 Japan
Tel: 81-45-471- 6166 Fax: 81-45-471-6122
Arizona Microchip Technology SARL
Parc d’Activite du Moulin de Massy
43 Rue du Saule Trapu
Batiment A - ler Etage
91300 Massy, France
Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79
Korea
Germany
Microchip Technology Korea
168-1, Youngbo Bldg. 3 Floor
Samsung-Dong, Kangnam-Ku
Seoul, Korea
Tel: 82-2-554-7200 Fax: 82-2-558-5934
Arizona Microchip Technology GmbH
Gustav-Heinemann-Ring 125
D-81739 München, Germany
Tel: 49-89-627-144 0 Fax: 49-89-627-144-44
Shanghai
Arizona Microchip Technology SRL
Centro Direzionale Colleoni
Palazzo Taurus 1 V. Le Colleoni 1
20041 Agrate Brianza
Milan, Italy
Tel: 39-039-65791-1 Fax: 39-039-6899883
Microchip Technology
RM 406 Shanghai Golden Bridge Bldg.
2077 Yan’an Road West, Hong Qiao District
Shanghai, PRC 200335
Tel: 86-21-6275-5700 Fax: 86 21-6275-5060
Italy
11/15/99
Microchip received QS-9000 quality system
certification for its worldwide headquarters,
design and wafer fabrication facilities in
Chandler and Tempe, Arizona in July 1999. The
Company’s quality system processes and
procedures are QS-9000 compliant for its
PICmicro® 8-bit MCUs, KEELOQ® code hopping
devices, Serial EEPROMs and microperipheral
products. In addition, Microchip’s quality
system for the design and manufacture of
development systems is ISO 9001 certified.
All rights reserved. © 1999 Microchip Technology Incorporated. Printed in the USA. 11/99
Printed on recycled paper.
Information contained in this publication regarding device applications and the like is intended for suggestion only and may be superseded by updates. No representation or warranty is given and no liability is assumed
by Microchip Technology Incorporated with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights arising from such use or otherwise. Use of Microchip’s products
as critical components in life support systems is not authorized except with express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, under any intellectual property rights. The Microchip
logo and name are registered trademarks of Microchip Technology Inc. in the U.S.A. and other countries. All rights reserved. All other trademarks mentioned herein are the property of their respective companies.
 1999 Microchip Technology Inc.