我正在尝试制作一个将十六进制转换为二进制的程序，但是我的程序却相反。如何解决这个问题？

Question

.model small
.stack
.data     
    msg1 db "Enter hexadecimal number:$"
    msg2 db "The binary value is:$"   
    msg3 db "The number of 1's is:$"
    msg4 db "The number of 0's is:$" 
    countone db ?
    countzero db ? 

.code       
main proc
    mov ax,@data
    mov ds,ax  


    clear:
    mov ah,2
    mov dl,0dh
    int 21h
    mov dl,0ah
    int 21h

    mov ah,9
    lea dx,msg1
    int 21h

    xor bh,bh

    input:
    mov ah,1
    int 21h

    mov ch,al 

    cmp ch,0dh
    je print

    cmp ch,'0'
    jl exit

    cmp ch,'1'
    jg exit

    and ch,15
    shl bh,1
    or bh,ch  

    jmp input

print:
    mov ah,2
    mov dl,0dh
    int 21h
    mov dl,0ah
    int 21h

    mov ah,9
    lea dx,msg2
    int 21h

    mov ah,2

    cmp bh,9
    jle number

    cmp bh,15
    jle character

number:
    add bh,48
    mov ah,2
    mov dl,bh
    int 21h 

    mov ah,2
    mov dl,13
    int 21h
    mov dl,10
    int 21h

    mov ah,9
    lea dx,msg3
    int 21h

    mov ah,2
    mov dl,13
    int 21h
    mov dl,10
    int 21h

    mov ah,9
    lea dx,msg4
    int 21h 
    jmp clear


character:
    add bh,55
    mov ah,2
    mov dl,bh
    int 21h 

    mov ah,2
    mov dl,13
    int 21h
    mov dl,10
    int 21h

    mov ah,9
    lea dx,msg3
    int 21h

    mov ah,2
    mov dl,13
    int 21h
    mov dl,10
    int 21h

    mov ah,9
    lea dx,msg4
    int 21h 
    jmp clear





exit:
  mov ah,2
  mov dl,0dh
  int 21h
  mov dl,0ah 
  int 21h

  mov ah,4ch
  int 21h
 main endp
END main