;T0809.asm
;A/D轉(zhuǎn)換實驗

;****************根據(jù)查看端口資源修改下列符號值*******************
IOY0         EQU   9C00H          ;片選IOY0對應的端口始地址
;*****************************************************************
AD0809       EQU   IOY0+00H       ;AD0809的端口地址

STACK1 SEGMENT STACK
        DW 256 DUP(?)
STACK1 ENDS

DATA SEGMENT
STR1   DB  'AD0809:IN0  $'        ;定義顯示的字符串
DATA ENDS

CODE SEGMENT
	ASSUME CS:CODE,DS:DATA

START: MOV AX,DATA
	   MOV DS,AX

LOOP1: MOV DX,AD0809             ;啟動A/D轉(zhuǎn)換
	   OUT DX,AL
	   CALL DALLY

	   MOV DX,OFFSET STR1        ;顯示字符串AD0809:IN0
	   MOV AH,9
	   INT 21H

       MOV DX,AD0809             ;讀出轉(zhuǎn)換結(jié)果
       IN AL,DX

       MOV CH,AL                 ;分析結(jié)果進行顯示
       AND AL,0F0H
	   MOV CL,04H
	   SHR AL,CL                 ;取出數(shù)據(jù)的十位
	   CMP AL,09H
	   JG A1

	   ADD AL,30H                
	   JMP A2
A1:	   ADD AL,37H                ;對A～F的處理 
A2:    MOV DL,AL                 ;對0～9的處理 
       MOV AH,02H
	   INT 21H

       MOV AL,CH               
	   AND AL,0FH                ;取出數(shù)據(jù)的各位
	   CMP AL,09H
	   JG A3

	   ADD AL,30H
	   JMP A4
A3:	   ADD AL,37H                ;對A～F的處理 
A4:	   MOV DL,AL                 ;對0～9的處理 
       MOV AH,02H
	   INT 21H

       MOV DL,0DH                ;回車，置光標到行首
       MOV AH,02H
	   INT 21H

       MOV AH,1                  ;判斷是否有按鍵按下
       INT 16H
       JZ  LOOP1                 ;無按鍵則跳回繼續(xù)循環(huán)，有則退出

QUIT:  MOV AX,4C00H              ;結(jié)束程序退出
       INT 21H

DALLY PROC NEAR	                 ;軟件延時子程序
       PUSH CX
	   PUSH AX
	   MOV CX,4000H
D1:    MOV AX,0600H
D2:	   DEC AX
	   JNZ D2
	   LOOP D1
	   POP AX
	   POP CX
	   RET
DALLY ENDP

CODE ENDS
     END START