adcconv.asm

ADI公司的产品aduc824单片机的ADC转换程序

;======================================================================
;
; Author        : ADI - Apps
;
; Date          : Sept. 1999
;
; File          : adcconv.asm
;
; Hardware      : ADuC824
;
; Description   : example routine to continuosuly trigger 
;		  a single conversion on the ADC main channel 
;		  The Conversion result is written to external memory, 
;		  P3.4 is toggled 5 times at 100ms delay
;		  The ADC result is written to external memory
;		  P3.4 is toggled 5 times at 500ms
;		  and the sequence repeats itself.
;
;======================================================================
;       
$MOD824					; Use 8052 predefined Symbols

FLAG	EQU	00H			; Define Bit


CSEG					; Defines the following as a segment of code

ORG     0000H				; Load Code at '0'	

		JMP     START		; Jump to START
;
;======================================================================
;
ORG 0033H				; Read ADC Result H/M/L to external Memory

					; 10 flashes at 100ms
		MOV	A,#01H		; 100msec delay
		MOV	R3,#0Ah		; loop=5
TIC1:		CPL 	P3.4		; Toggle LED
		CALL	DELAY		; Delay 100mSec
		DJNZ	R3,TIC1		; Dec loop

		MOV	DPTR, #00H	; DPTR=00
		MOV	A,ADC0L		; read ADC low byte 
		MOVX	@DPTR,A		; write low byte to ext memory
		INC	DPTR		; DPTR=01
		MOV	A,ADC0M		; read ADC Middle byte 
		MOVX	@DPTR,A		; write Middle byte to ext memory
		INC	DPTR		; DPTR=02
		MOV	A,ADC0H		; read ADC High byte 
		MOVX	@DPTR,A		; write low High byte to ext memory
		INC	DPTR
	
					; 5 flashes at 500ms
		MOV	A,#05H		; 500msec delay
		MOV	R3,#0Ah		; loop=10
TIC2:		CPL 	P3.4		; Toggle LED
		CALL	Delay		; Delay 100mSec
		DJNZ	R3,TIC2		; Dec loop
;
		SETB	Flag		; Set Flag
		
		RETI			; Return from Interrupt
;
;======================================================================
;
ORG 0060H
START:
					; Configure Interrupt System
		SETB	IT0		; CONFIG EXTERNAL INTERRUPT Falling Edge
		SETB	EA		; Enable Global Interrupts
		
					; Configure ADC
		MOV	ADCMODE,#20H	; ENABLE MAIN ADC; Mode- Power down 
		MOV	ADC0CON,#40H	; 24 BITS
					; USE EXTERNAL REFERENCE
					; AIN1-AIN2 
					; BIPOLAR MODE
					; RANGE = +/-20mV 
		SETB	EADC		; ENABLE ADC INTERRUPT

					; Looped single conversions			
CONV:		CLR 	FLAG		; Initial condition for FLAG variable
		MOV	ADCMODE,#22H	; INITIATE A MAIN ADC SINGLE CONVERSION
		CALL	DELAY		; Jump to subroutine DELAY
		JNB	FLAG,$		; Stay here until FLAG=1 i.e. wait for ADC Int.
		JMP	CONV		; Next ADC Conversion
;	
;======================================================================
;

DELAY:					; Delays by A*100ms (default Core Clk =1.57MHz)
		MOV	R0,A		; Acc holds delay variable
 DLY0:		MOV	R1,#0FEh	; Set up delay loop0
 DLY1:		MOV	R2,#019h	; Set up delay loop1
		DJNZ	R2,$		; Dec R2 & Jump here until R2 is 0
		DJNZ	R1,DLY1         ; Dec R1 & Jump DLY1 until R1 is 0
		DJNZ	R0,DLY0		; Dec R0 & Jump DLY0 until R0 is 0
		RET			; Return from subroutine		
;
END