ADC 8bit, 10bit, 12bit bằng MPASM

[tallht]

                       PROCESSOR PIC16F877A
	          INCLUDE <P16F877A.INC>
	    __CONFIG _XT_OSC & _WDT_OFF & _LVP_OFF & _CP_OFF
;*************************************************************
;CHUONG TRINH THU NGHIEM DUNG ADC CUA PIC 16F877A
;*************************************************************
;NGUOI THUC HIEN: TALLHT
;*************************************************************
;*************************************************************	
		COUNT 	EQU 0X20	;BIEN DELAY
		COUNT1	EQU 0X21
;************************************************************	
MAIN	
		BANKSEL TRISB
		CLRF TRISB		;PORTB XUAT LED
		MOVLW 0XFF
		MOVWF TRISA		;PORT A LA INPUT
LOOP	
		BANKSEL ADCON1
		MOVLW 0X00		;NGO VAO ANALOG,Fosc/2
		MOVWF ADCON1
		BANKSEL ADCON0
		MOVLW	0X01		;CHON RA0 LAM NGO VAO,ADON=1,BAT ADC
		MOVWF ADCON0
		CALL DELAY		;CHO 1 KHOANG THOI GIAN TRUOC KHI BAT DAU
		BSF ADCON0,GO		;SET BIT "GO",BAT DAU CONVERT
;***************************************
;KIEM TRA KET QUA
		BTFSC ADCON0,GO			;KIEM TRA BIT "DONE" CUA ADCON0
		GOTO $-1			;NEU BANG 1 THI CHO TIEP TUC
		MOVF ADRES,W                              ;LAY KẾT QUẢ VÀO W
		MOVWF PORTB			;XUAT RA PORTB
		GOTO LOOP
;*******************************************************
DELAY
		MOVLW D'10'
		MOVWF COUNT
BACK
		MOVLW D'4'
		MOVWF COUNT1
		DECFSZ COUNT1,F
		GOTO $-1
		DECFSZ COUNT,F
		GOTO BACK
		RETURN
END