Question 6.10: Read and test P1 to see whether it has the value 45H. If it ...

MOV    P2,#00        ;clear P2
MOV    P1,#0FFH   ;make P1 an input port
MOV    R3,#45H     ;R3=45H
MOV    A,P1             ;read P1
XRL^{\nearrow ^{\fbox{XRL can be used to see if two registers have the same value } } }     A,R3
JNZ^{\nearrow ^{\fbox{If both registers have the same value, 00 is placed in A. JNZ and JZ test the contents of the accumulator. } } }     EXIT            ;jump if A is not 0
MOV   P2,#99H

EXIT:           . . .