PIC16F753 Datasheet, PDF (117/238 Pages) Microchip Technology – 14/16-Pin, Flash-Based 8-Bit CMOS Microcontrollers

12.2.6 A/D CONVERSION PROCEDURE
This is an example procedure for using the ADC to
perform an Analog-to-Digital conversion:
1. Configure Port:
• Disable pin output driver (See TRIS register)
• Configure pin as analog
2. Configure the ADC module:
• Select ADC conversion clock
• Configure voltage reference
• Select ADC input channel
• Select result format
• Turn on ADC module
3. Configure ADC interrupt (optional):
• Clear ADC interrupt flag
• Enable ADC interrupt
• Enable peripheral interrupt
• Enable global interrupt⁽¹⁾
4. Wait the required acquisition time⁽²⁾.
5. Start conversion by setting the GO/DONE bit.
6. Wait for ADC conversion to complete by one of
the following:
• Polling the GO/DONE bit
• Waiting for the ADC interrupt (interrupts
enabled)
7. Read ADC Result
8. Clear the ADC interrupt flag (required if interrupt
is enabled).
Note 1: The global interrupt can be disabled if the
user is attempting to wake-up from Sleep
and resume in-line code execution.
2: See Section 12.4 “A/D Acquisition
Requirements”.
PIC16F753/HV753
EXAMPLE 12-1: A/D CONVERSION
;This code block configures the ADC
;for polling, Vdd reference, Frc clock
;and RA0 input.
;
;Conversion start & polling for completion
; are included.
;
BANKSEL TRISA
;
BSF
TRISA,0
;Set RA0 to input
BANKSEL ADCON1
;
MOVLW B’01110000’ ;ADC Frc clock,
IORWF ADCON1
; and RA0 as analog
BANKSEL ADCON0
;
MOVLW B’10000001’ ;Right justify,
MOVWF ADCON0
;Vdd Vref, AN0, On
CALL SampleTime ;Acquisiton delay
BSF
ADCON0,GO ;Start conversion
TEST AGAIN
BTFSC ADCON0,GO ;Is conversion done?
GOTO TEST AGAIN ;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
 2013 Microchip Technology Inc.
Preliminary
DS40001709A-page 117