Microchip Technology MA180025 Data Sheet

DS39933D-page 126

 2010 Microchip Technology Inc.

PORTD is an 8-bit wide, bidirectional port. The
corresponding Data Direction and Output Latch registers
are TRISD and LATD. All pins on PORTD are digital only
and tolerate voltages up to 5.5V.
All pins on PORTD are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.

Each of the PORTD pins has a weak internal pull-up. A
single control bit can turn off all the pull-ups. This is
performed by clearing bit, RDPU (PORTG<7>). The
weak pull-up is automatically turned off when the port
pin is configured as an output. The pull-ups are
disabled on all device Resets.

All of the PORTD pins are multiplexed with LCD
segment drives, controlled by bits in the LCDSE0
register. RD0 is multiplexed with the CTMU pulse
generator output.
I/O port functionality is only available when the LCD
segments are disabled.

These pins are configured as digital inputs
on any device Reset.

CLRF

PORTD

;

  Initialize PORTD by

 

; clearing output

 

; data latches

CLRF

LATD

; Alternate method

; to clear output

; data latches

MOVLW

 

0CFh

;

  Value used to 

; initialize data 

; direction

MOVWF

 

TRISD

;

  Set RD<3:0> as inputs

;

  RD<5:4> as outputs

;

  RD<7:6> as inputs