Datasheet

PIC16F631/677/685/687/689/690
DS40001262F-page 110  2005-2015 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.
;
BANKSELADCON1;
MOVLWB’01110000’;ADC Frc clock
MOVWFADCON1;
BANKSELTRISA;
BSF TRISA,0;Set RA0 to input
BANKSELANSEL;
BSF ANSEL,0;Set RA0 to analog
BANKSELADCON0;
MOVLWB’10000001’;Right justify,
MOVWFADCON0; Vdd Vref, AN0, On
CALLSampleTime;Acquisiton delay
BSF ADCON0,GO;Start conversion
BTFSCADCON0,GO;Is conversion done?
GOTO$-1 ;No, test again
BANKSELADRESH;
MOVFADRESH,W;Read upper 2 bits
MOVWFRESULTHI;store in GPR space
BANKSELADRESL;
MOVFADRESL,W;Read lower 8 bits
MOVWFRESULTLO;Store in GPR space