PIC18F45K80-I Datasheet, PDF (175/622 Pages) Microchip Technology – 28/40/44/64-Pin, Enhanced Flash Microcontrollers with ECAN and nanoWatt XLP Technology

PIC18F66K80 FAMILY
11.2 PORTA, TRISA and
LATA Registers
PORTA is a seven-bit wide, bidirectional port. The cor-
responding Data Direction and Output Latch registers
are TRISA and LATA.
RA5 and RA<3:0> are multiplexed with analog inputs
for the A/D Converter.
The operation of the analog inputs as A/D Converter
inputs is selected by clearing or setting the ANSELx
control bits in the ANCON1 register. The corresponding
TRISA bits control the direction of these pins, even
when they are being used as analog inputs. The user
must ensure the bits in the TRISA register are
maintained set when using them as analog inputs.
Note:
RA5 and RA<3:0> are configured as
analog inputs on any Reset and are read
as ‘0’.
OSC2/CLKO/RA6 and OSC1/CLKI/RA7 normally
serve as the external circuit connections for the exter-
nal (primary) oscillator circuit (HS Oscillator modes) or
the external clock input and output (EC Oscillator
modes). In these cases, RA6 and RA7 are not available
as digital I/O and their corresponding TRIS and LAT
bits are read as ‘0’. When the device is configured to
use HF-INTOSC, MF-INTOSC or LF-INTOSC as the
default oscillator mode, RA6 and RA7 are automatically
configured as digital I/O; the oscillator and clock
in/clock out functions are disabled.
RA5 has additional functionality for Timer1 and Timer3.
It can be configured as the Timer1 clock input or the
Timer3 external clock gate input.
EXAMPLE 11-1: INITIALIZING PORTA
CLRF
CLRF
MOVLW
MOVWF
MOVLW
MOVWF
PORTA
LATA
00h
ANCON1
0BFh
TRISA
; Initialize PORTA by
; clearing output latches
; Alternate method to
; clear output data latches
; Configure A/D
; for digital inputs
; Value used to initialize
; data direction
; Set RA<7, 5:0> as inputs,
; RA<6> as output
 2010-2012 Microchip Technology Inc.
DS39977F-page 175