PIC16F818/819
FIGURE 1-1:
PIC16F818/819 BLOCK DIAGRAM
13
8
PORTA
Data Bus
RA0/AN0
Program Counter
RA1/AN1
Flash
RA2/AN2/VREF-
RA3/AN3/VREF+
RA4/AN4/T0CKI
RA5/MCLR/VPP
RA6/OSC2/CLKO
RA7/OSC1/CLKI
Program
Memory
1K/2K x 14
RAM
File
Registers
8-Level Stack
(13-bit)
128/256 x 8
Program
Bus
14
RAM Addr(1)
9
PORTB
RB0/INT
Addr MUX
Instruction reg
RB1/SDI/SDA
RB2/SDO/CCP1
RB3/CCP1/PGM
RB4/SCK/SCL
RB5/SS
Indirect
Addr
7
Direct Addr
8
FSR reg
RB6/T1OSO/T1CKI/PGC
RB7/T1OSI/PGD
Status reg
8
3
MUX
Power-up
Timer
Oscillator
Instruction
Decode &
Control
Start-up Timer
ALU
Power-on
Reset
8
Timing
Generation
Watchdog
Timer
W reg
RA7/OSC1/CLKI
RA6/OSC2/CLKO
Brown-out
Reset
MCLR VDD, VSS
Data EE
128/256 Bytes
Timer0
Timer1
Timer2
Synchronous
Serial Port
10-bit, 5-channel
A/D
CCP1
Note 1: Higher order bits are from the Status register.
DS39598E-page 6
2004 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
