PIC18F87J10 Datasheet, PDF (138/394 Pages) Microchip Technology – 64/80-Pin High-Performance, 1-Mbit Flash Microcontrollers with nanoWatt Technology

PIC18F87J10 FAMILY
10.10 PORTJ, TRISJ and
LATJ Registers
Note: PORTJ is available only on 80-pin devices.
PORTJ is an 8-bit wide, bidirectional port. The corre-
sponding data direction register is TRISJ. Setting a
TRISJ bit (= 1) will make the corresponding PORTJ pin
an input (i.e., put the corresponding output driver in a
high-impedance mode). Clearing a TRISJ bit (= 0) will
make the corresponding PORTJ pin an output (i.e., put
the contents of the output latch on the selected pin). All
pins on PORTJ are digital only and tolerate voltages up
to 5.5V.
The Data Latch register (LATJ) is also memory
mapped. Read-modify-write operations on the LATJ
register read and write the latched output value for
PORTJ.
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.
When the external memory interface is enabled, all of
the PORTJ pins function as control outputs for the
interface. This occurs automatically when the interface
is enabled by clearing the EBDIS control bit
(MEMCON<7>). The TRISJ bits are also overridden.
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 PORTG by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
; Value used to
; initialize data
; direction
; Set RJ3:RJ0 as inputs
; RJ5:RJ4 as output
; RJ7:RJ6 as inputs
DS39663A-page 136
Advance Information
 2005 Microchip Technology Inc.