PIC17C7XX_13 Datasheet, PDF (91/306 Pages) Microchip Technology – High-Performance 8-bit CMOS EPROM Microcontrollers with 10-bit A/D

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.
PIC17C7XX
EXAMPLE 10-9: INITIALIZING PORTJ
MOVLB
CLRF
MOVLW
MOVWF
8
PORTJ, F
0xCF
DDRJ
; Select Bank 8
; Initialize PORTJ data
; latches before setting
; the data direction
; register
; Value used to initialize
; data direction
; Set RJ<3:0> as inputs
; RJ<5:4> as outputs
; RJ<7:6> as inputs
FIGURE 10-19: PORTJ BLOCK DIAGRAM
D
Q
EENN
VDD
D
P
Q ^CK
Q
D
N
Q _CK
Note: I/O pins have protection diodes to VDD and VSS.
Data Bus
RD_PORTJ
WR_PORTJ
RD_DDRJ
WR_DDRJ
 1998-2013 Microchip Technology Inc.
DS30289C-page 91