Datasheet

Table Of Contents
PIC16F631/677/685/687/689/690
DS41262E-page 112 © 2008 Microchip Technology Inc.
EXAMPLE 9-1: A/D CONVERSION
9.2.7 ADC REGISTER DEFINITIONS
The following registers are used to control the
operation of the ADC.
;This code block configures the ADC
;for polling, Vdd reference, Frc clock
;and AN0 input.
;
;Conversion start & polling for completion
; are included.
;
BANKSEL ADCON1 ;
MOVLW B’01110000’ ;ADC Frc clock
MOVWF ADCON1 ;
BANKSEL TRISA ;
BSF TRISA,0 ;Set RA0 to input
BANKSEL ANSEL ;
BSF ANSEL,0 ;Set RA0 to analog
BANKSEL ADCON0 ;
MOVLW B’10000001’ ;Right justify,
MOVWF ADCON0 ; Vdd Vref, AN0, On
CALL SampleTime ;Acquisiton delay
BSF ADCON0,GO ;Start conversion
BTFSC ADCON0,GO ;Is conversion done?
GOTO $-1 ;No, test again
BANKSEL ADRESH ;
MOVF ADRESH,W ;Read upper 2 bits
MOVWF RESULTHI ;store in GPR space
BANKSEL ADRESL ;
MOVF ADRESL,W ;Read lower 8 bits
MOVWF RESULTLO ;Store in GPR space