Question

Write an assembly language program to check whether fourth and fifth bits of a hexadecimal number stored in memory location D900H is logical one then store 00H else FFH of memory location D901H.

Answer 1

Label    Instructions      Comments 

         LXI H, D900H  ; Load HL to D900H       
         MOV A, M      ; Move M to A           
         ANI 18H       ; AND with 18H          
         SUI 18H       ; Subtract 18H with A    
         JZ Store      ; Jump on zero go to store
         MVI A, FFH    ; SET A To FFH             
Store    STA D901H     ; Store A to D901H        
         HLT           ; Stop