PIC16C923T-08I/SP View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16C923T-08I/SP

8-Bit CMOS Microcontroller with LCD Driver

Microchip Technology 

PIC16C9XX

12.4 A/D Conversions

Example 12-2 show how to perform an A/D conversion.

The RA pins are configured as analog inputs. The ana-

log reference (VREF) is the device VDD. The A/D inter-

rupt is enabled, and the A/D conversion clock is FRC.

The conversion is performed on the RA0 pin

(channel0).

Note: The GO/DONE bit should NOT be set in

the same instruction that turns on the A/D.

Clearing the GO/DONE bit during a conversion will

abort the current conversion. The ADRES register will

NOT be updated with the partially completed A/D con-

version sample. That is, the ADRES register will con-

tinue to contain the value of the last completed

conversion (or the last value written to the ADRES reg-

ister). After the A/D conversion is aborted, a 2TAD wait

is required before the next acquisition is started. After

this 2TAD wait, an acquisition is automatically started on

the selected channel.

EXAMPLE 12-2: DOING AN A/D CONVERSION

BCF

STATUS, RP1

; Select Bank1

BSF

STATUS, RP0

;

CLRF ADCON1

; Configure A/D inputs

BSF

PIE1, ADIE

; Enable A/D interrupts

BCF

STATUS, RP0

; Select Bank0

MOVLW 0xC1

; RC Clock, A/D is on, Channel 0 is selected

MOVWF ADCON0

;

BCF

PIR1, ADIF

; Clear A/D interrupt flag bit

BSF

INTCON, PEIE

; Enable peripheral interrupts

BSF

INTCON, GIE

; Enable all interrupts

;

; Ensure that the required acquisition time for the selected input channel has elapsed.

; Then the conversion may be started.

;

BSF

ADCON0, GO

; Start A/D Conversion

:

; The ADIF bit will be set and the GO/DONE bit

:

; is cleared upon completion of the A/D Conversion.

DS30444E - page 84

© 1997 Microchip Technology Inc.

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