Mask Lower Nibble Algorithm Snapshot

Masking Lower Nibble Code

.model small                                                                 
 .data  
 a dw 0012H  
 .code  
      mov      ax, @data          ; Initialize data section  
      mov      ds, ax  
      mov      ax, a              ; Load number1 in ax  
      and      al, 0f0h           ; mask lower nibble.Result in al  
      mov      ch, 02h            ; Count of digits to be displayed  
      mov      cl, 04h            ; Count to roll by 4 bits  
      mov      bh, al             ; Result in reg bh  
 l2:     rol      bh, cl          ; roll bl so that msb comes to lsb   
      mov      dl, bh             ; load dl with data to be displayed  
      and      dl, 0fH            ; get only lsb  
      cmp      dl, 09             ; check if digit is 0-9 or letter A-F  
      jbe      l4  
      add      dl, 07             ; if letter add 37H else only add 30H  
 l4:      add      dl, 30H       
      mov     ah, 02              ; Function 2 under INT 21H (Display character)  
      int      21H  
      dec      ch                 ; Decrement Count  
      jnz      l2     
      mov      ah, 4ch  
      int      21h  
      end