Information

PIC18F8722 FAMILY
DS39646C-page 154 © 2008 Microchip Technology Inc.
11.8 PORTH, LATH and
TRISH Registers
PORTH is an 8-bit wide, bidirectional I/O port. The
corresponding Data Direction register is TRISH. Set-
ting a TRISH bit (= 1) will make the corresponding
PORTH pin an input (i.e., put the corresponding output
driver in a high-impedance mode). Clearing a TRISH
bit (= 0) will make the corresponding PORTH pin an
output (i.e., put the contents of the output latch on the
selected pin).
The Data Latch register (LATH) is also memory
mapped. Read-modify-write operations on the LATH
register, read and write the latched output value for
PORTH.
All pins on PORTH are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
When the external memory interface is enabled, four of
the PORTH pins function as the high-order address
lines for the interface. The address output from the
interface takes priority over other digital I/O. The
corresponding TRISH bits are also overridden.
EXAMPLE 11-8: INITIALIZING PORTH
Note: PORTH is available only on
PIC18F8527/8622/8627/8722 devices.
Note: On a Power-on Reset, these pins are
configured as digital inputs.
CLRF PORTH ; Initialize PORTH by
; clearing output
; data latches
CLRF LATH ; Alternate method
; to clear output
; data latches
MOVLW 0CFh ; Value used to
; initialize data
; direction
MOVWF TRISH ; Set RH3:RH0 as inputs
; RH5:RH4 as outputs
; RH7:RH6 as inputs