Datasheet

PIC16F872
DS30221C-page 4 © 2006 Microchip Technology Inc.
FIGURE 1-1: PIC16F872 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
Instruction
Decode &
Control
Timing
Generation
OSC1/CLKIN
OSC2/CLKOUT
MCLR
VDD, VSS
PORTA
PORTB
PORTC
RA4/T0CKI
RA5/AN4/SS
RB0/INT
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2
RC2/CCP1
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO
RC6
RC7
8
8
Brown-out
Reset
Note 1: Higher order bits are from the STATUS register.
CCP
Synchronous
10-bit A/D
Timer0 Timer1 Timer2
Serial Port
RA3/AN3/VREF+
RA2/AN2/VREF-
RA1/AN1
RA0/AN0
8
3
Data EEPROM
RB1
RB2
RB3/PGM
RB4
RB5
RB6/PGC
RB7/PGD
In-Circuit
Debugger
Low Voltage
Programming