Datasheet

© 2006 Microchip Technology Inc. DS39564C-page 9
PIC18FXX2
FIGURE 1-2: PIC18F4X2 BLOCK DIAGRAM
Power-up
Timer
Oscillator
Start-up Timer
Power-on
Reset
Watchdog
Timer
Instruction
Decode &
Control
OSC1/CLKI
OSC2/CLKO
MCLR
VDD, VSS
PORTA
PORTB
PORTC
RA4/T0CKI
RA5/AN4/SS
/LVDIN
RB0/INT0
RB4
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2
(1)
RC2/CCP1
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO
RC6/TX/CK
RC7/RX/DT
Brown-out
Reset
Note 1: Optional multiplexing of CCP2 input/output with RB3 is enabled by selection of configuration bit.
2: The high order bits of the Direct Address for the RAM are from the BSR register (except for the MOVFF instruction).
3: Many of the general purpose I/O pins are multiplexed with one or more peripheral module functions. The multiplexing combinations
are device dependent.
Addressable
CCP1
Master
Timer0
Timer1 Timer2
Serial Port
RA3/AN3/VREF+
RA2/AN2/VREF-
RA1/AN1
RA0/AN0
Parallel Slave Port
Timing
Generation
4X PLL
A/D Converter
RB1/INT1
Data Latch
Data RAM
(up to 4K
address reach)
Address Latch
Address<12>
12
(2)
Bank0, F
BSR
FSR0
FSR1
FSR2
4
12 4
PCH PCL
PCLATH
8
31 Level Stack
Program Counter
PRODLPRODH
8 x 8 Multiply
WREG
8
BIT OP
8
8
ALU<8>
8
Address Latch
Program Memory
(up to 2 Mbytes)
Data Latch
21
21
16
8
8
8
inc/dec logic
21
8
Data Bus<8>
Table Latch
8
Instruction
12
3
ROM Latch
Timer3
PORTD
PORTE
RE0/AN5/RD
RE1/AN6/WR
RE2/AN7/CS
CCP2
RB2/INT2
RB3/CCP2
(1)
T1OSCI
T1OSCO
PCLATU
PCU
RA6
Precision
Reference
Voltage
Synchronous
USART
Register
8
Table Pointer
inc/dec
logic
Decode
RD0/PSP0
RD1/PSP1
RD2/PSP2
RD3/PSP3
RD4/PSP4
RD5/PSP5
RD6/PSP6
RD7/PSP7
Low Voltage
Programming
In-Circuit
Debugger
Data EEPROM
RB5/PGM
RB6/PCG
RB7/PGD