PIC18F87J90 Datasheet, PDF (137/450 Pages) Microchip Technology – 64/80-Pin, High-Performance Microcontrollers with LCD Driver and nanoWatt Technology

PIC18F87J90 FAMILY
10.10 PORTJ, TRISJ and
LATJ Registers
Note: PORTJ is available only on PIC18F8XJ90
devices.
PORTJ is an 8-bit wide, bidirectional port. The
corresponding Data Direction and Output Latch registers
are TRISJ and LATJ. All pins on PORTJ are digital only
and tolerate voltages up to 5.5V.
All pins on PORTJ are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
Note: These pins are configured as digital inputs
on any device Reset.
All PORTJ pins, except RJ0, are multiplexed with LCD
segment drives controlled by the LCDSE4 register. I/O
port functions are only available on these pins when the
segments are disabled.
Each of the PORTJ pins has a weak internal pull-up.
The pull-ups are provided to keep the inputs at a known
state for the external memory interface while powering
up. A single control bit can turn off all the pull-ups. This
is performed by clearing bit, RJPU (PORTG<5>). The
weak pull-up is automatically turned off when the port
pin is configured as an output. The pull-ups are
disabled on any device Reset.
EXAMPLE 10-9: INITIALIZING PORTJ
CLRF
CLRF
MOVLW
MOVWF
PORTJ
LATJ
0CFh
TRISJ
; Initialize PORTJ by
; clearing output latches
; Alternate method
; to clear output latches
; Value used to
; initialize data
; direction
; Set RJ3:RJ0 as inputs
; RJ5:RJ4 as output
; RJ7:RJ6 as inputs
 2010 Microchip Technology Inc.
DS39933D-page 137