Datasheet

 1998-2013 Microchip Technology Inc. DS30289C-page 91

PIC17C7XX

10.9 PORTJ and DDRJ Registers

(PIC17C76X only)

PORTJ is an 8-bit wide, bi-directional port. The corre-

sponding data direction register is DDRJ. A '1' in DDRJ

configures the corresponding port pin as an input. A '0'

in the DDRJ register configures the corresponding port

pin as an output. Reading PORTJ reads the status of

the pins, whereas writing to PORTJ will write to the

respective port latch.

PORTJ is a general purpose I/O port.

EXAMPLE 10-9: INITIALIZING PORTJ

FIGURE 10-19: PORTJ BLOCK DIAGRAM

MOVLB 8 ; Select Bank 8

CLRF PORTJ, F ; Initialize PORTJ data

; latches before setting

; the data direction

; register

MOVLW 0xCF ; Value used to initialize

; data direction

MOVWF DDRJ ; Set RJ<3:0> as inputs

; RJ<5:4> as outputs

; RJ<7:6> as inputs

Note: I/O pins have protection diodes to VDD and VSS.

Data Bus

RD_PORTJ

WR_PORTJ

RD_DDRJ

WR_DDRJ

VDD