
1999 Microchip Technology Inc.
DS30292B-page 5
PIC16F87X
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.
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.
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
FLASH
Program
Memory
13
Data Bus
8
14
Program
Bus
Instruction reg
Program Counter
8 Level Stack
(13-bit)
RAM
File
Registers
Direct Addr
7
RAM Addr (1)
9
Addr MUX
Indirect
Addr
FSR reg
STATUS reg
MUX
ALU
W reg
Power-up
Timer
Oscillator
Start-up Timer
Power-on
Reset
Watchdog
Timer
Brown-out
Reset
In-Circuit
Debugger
Instruction
Decode &
Control
Timing
Generation
OSC1/CLKIN
OSC2/CLKOUT
MCLR
V
DD
, V
SS
PORTA
PORTB
PORTC
RA4/T0CKI
RA5/AN4/SS
RB0/INT
RB1
RB2
RB3/PGM
RB4
RB5
RB6/PGC
RB7/PGD
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2
RC2/CCP1
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO
RC6/TX/CK
RC7/RX/DT
8
8
Note 1:
Higher order bits are from the STATUS register.
USART
CCP1,2
Synchronous
Serial Port
10-bit A/D
Timer0
Timer1
Timer2
RA3/AN3/V
REF
+
RA2/AN2/V
REF
-
RA1/AN1
RA0/AN0
8
3
Data EEPROM
Device
Program
FLASH
4K
8K
Data Memory
Data
EEPROM
128 Bytes
256 Bytes
PIC16F873
PIC16F876
192 Bytes
368 Bytes
Low-Voltage
Programming