Datasheet

PIC16F818/819
DS39598F-page 6  2001-2013 Microchip Technology Inc.
FIGURE 1-1: PIC16F818/819 BLOCK DIAGRAM
Flash
Memory
1K/2K x 14
13
Data Bus
8
14
Program
Bus
Instruction reg
Program Counter
8-Level Stack
(13-bit)
RAM
File
Registers
128/256 x 8
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
RA7/OSC1/CLKI
RA6/OSC2/CLKO
MCLR
VDD, VSS
Timer0
10-bit, 5-channel
Synchronous
Serial Port
PORTA
8
8
Brown-out
Reset
Note 1: Higher order bits are from the Status register.
CCP1
Timer1 Timer2
RA5/MCLR/VPP
RA6/OSC2/CLKO
RA4/AN4/T0CKI
RA3/AN3/VREF+
RA2/AN2/VREF-
RA1/AN1
8
3
Program
PORTB
RB0/INT
RB1/SDI/SDA
RB2/SDO/CCP1
RB3/CCP1/PGM
RB4/SCK/SCL
RB5/SS
RB6/T1OSO/T1CKI/PGC
RB7/T1OSI/PGD
RA7/OSC1/CLKI
RA0/AN0
128/256 Bytes
Data EE
A/D