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$MOD52

	rd1 equ P0.0           	;Read signal P0.0
        wr1 equ P0.1           	;Write signal P0.1
        cs equ P0.2           	;Chip Select P0.2
        intr equ P0.3         	;INTR signal P0.3

        adc_port EQU P2       	;ADC data pins P2
        adc_val EQU 30H       	;ADC read value stored here

        org 0H
start:                    	;Start of Program
        acall conv            	;Start ADC conversion
        acall read            	;Read converted value
        mov P3,adc_val        	;Move the value to Port 3
        sjmp start            	;Do it again

conv:                     	;Start of Conversion
        clr cs                	;Make CS low
        clr wr1                	;Make WR1 Low
        nop
        setb wr1               	;Make WR High
        setb cs               	;Make CS high
wait:
        jb intr,wait          	;Wait for INTR signal
        ret                   	;Conversion done

read:                     	;Read ADC value
        clr cs                	;Make CS Low
        clr rd1                	;Make RD1 Low
        mov a,adc_port        	;Read the converted value
        mov adc_val,a         	;Store it in local variable
        setb rd1               	;Make RD1 High
        setb cs               	;Make CS High
        ret                   	;Reading done

END

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