adc0808.asm

protues 仿真 adc0808和dac0808,很好的软件

;AD转换，用ADC0808，显示典型值
;参考电压为5V时，A--D的典型值为 0V--OOH,  2.5V--7FH,   5V--FFH
        ORG 0000H
		LJMP MAIN
		ORG 0030H

MAIN:   MOV R0,#0A0H
        MOV R1,#08H		
		MOV SCON,#00H

START:  MOV DPTR,#7FF8H
        
    	MOVX @DPTR,A  ;	产生WR\=0,START=1,开始AD转换

WAIT1:  JB P3.3,WAIT1

        MOVX A,@DPTR  ;	产生RD\=0,OE=1  ,读取AD转换的结果
        MOVX @R0,A

DISP:   MOV  R2,A      ;显示低位
        ANL A,#0FH
LP:     MOV DPTR,#TAB
        MOVC A,@A+DPTR	
		SETB P3.5
        MOV SBUF,A
WAIT2:  JNB TI,WAIT2
        CLR TI
	
	   
        MOV A,R2       ;显示高位
        SWAP A
        ANL A,#0FH
        MOVC A,@A+DPTR
		MOV SBUF,A
WAIT3:  JNB TI,WAIT3
        CLR TI
		CLR P3.5
       
        LCALL DELAY
        
		AJMP  MAIN

TAB:    DB 0fch,60h,0dah,0f2h,66h,0b6h,0beh,0e0h ;0,1,2,3,4,5,6,7
        DB 0feh,0f6h,0eeh,3eh,9ch,7ah,9eh,8eh    ;8,9,A,B,C,D,E,F
DELAY:  MOV R6,#0FFh
DELY2:  MOV R7,#0FFh
DELY1:  DJNZ R7,DELY1
        DJNZ R6,DELY2
        RET
        
		END