Question 6.17: Assume that the lower three bits of P1 are connected to thre...

The 8051 Microcontroller and Embedded Systems

Assume that the lower three bits of P1 are connected to three switches. Write a program to send the following ASCII characters to P2 based on the status of the switches.

000 ‘0’
001 ‘1’
010 ‘2’
011 ‘3’
100 ‘4’
101 ‘5’
110 ‘6’
111 ‘7’

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MOV DPTR,#MYTABLE
MOV A,P1 ;get SW status
ANL A,#07H ;mask all but lower 3
MOVC A,@A+DPTR ;get data from table
MOV P2,A ;display value
SJMP $ ;stay here

; – – – – – – – – – – – – – – – – – –

ORG 400H

MYTABLE DB ‘0’,‘1’,‘2’,‘3’,‘4’,‘5’,‘6’,‘7’

END

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