PIC16F87X
There are four devices (PIC16F873, PIC16F874,
PIC16F876 and PIC16F877) covered by this data
sheet. The PIC16F876/873 devices come in 28-pin
packages and the PIC16F877/874 devices come in 40-
pin packages. The 28-pin devices do not have a Paral-
lel Slave Port implemented.
1.0
DEVICE OVERVIEW
This document contains device-specific information.
Additional information may be found in the PICmicro™
Mid-Range Reference Manual, (DS33023), which may
be obtained from your local Microchip Sales Represen-
tative or downloaded from the Microchip website. The
Reference Manual should be considered a comple-
mentary document to this data sheet, and is highly rec-
ommended reading for a better understanding of the
device architecture and operation of the peripheral
modules.
The following two figures are device block diagrams
sorted by pin number; 28-pin for Figure 1-1 and 40-pin
for Figure 1-2. The 28-pin and 40-pin pinouts are listed
in Table 1-1 and Table 1-2, respectively.
FIGURE 1-1: PIC16F873 AND PIC16F876 BLOCK DIAGRAM
Device
Program
FLASH
Data Memory
Data
EEPROM
PIC16F873
PIC16F876
4K
8K
192 Bytes
368 Bytes
128 Bytes
256 Bytes
13
8
PORTA
Data Bus
Program Counter
RA0/AN0
RA1/AN1
RA2/AN2/VREF-
RA3/AN3/VREF+
RA4/T0CKI
FLASH
Program
Memory
RAM
File
Registers
8 Level Stack
(13-bit)
RA5/AN4/SS
Program
Bus
14
RAM Addr (1)
PORTB
9
RB0/INT
RB1
RB2
RB3/PGM
RB4
Addr MUX
Instruction reg
Indirect
Addr
7
Direct Addr
8
RB5
FSR reg
RB6/PGC
RB7/PGD
STATUS reg
PORTC
8
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2
RC2/CCP1
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO
3
MUX
Power-up
Timer
Oscillator
Start-up Timer
Instruction
Decode &
Control
RC6/TX/CK
RC7/RX/DT
ALU
Power-on
Reset
8
Timing
Generation
Watchdog
Timer
W reg
OSC1/CLKIN
OSC2/CLKOUT
Brown-out
Reset
In-Circuit
Debugger
Low-Voltage
Programming
MCLR VDD, VSS
Timer2
Timer0
Timer1
10-bit A/D
Data EEPROM
Synchronous
Serial Port
USART
CCP1,2
Note 1: Higher order bits are from the STATUS register.
1999 Microchip Technology Inc.
DS30292B-page 5
MICROCHIP [ MICROCHIP ]
