6-1'.asm

TCP_USB试验平台下的几个常见的实验的相应要求与代码

data segment
        t0 equ 280h
        t1 equ 281h
        t2 equ 282h
        ctl53 equ 283h
        pa equ 288h
        pb equ 289h
        pc equ 28ah
        ctl55 equ 28bh
        in0 equ 290h
       dat db ?
       table db 3fh,30h,5bh,4fh,66h,6dh,7dh,07h,7fh,6fh,77h,7ch,39h,0deh,7bh,71h
data ends
code segment
        assume  cs:code,ds:data
start:
       mov ax,data
       mov ds,ax
       xor ax,ax
       xor  bx,bx
       xor  cx,cx

       mov dx,ctl55
       mov al,10001000b
       out dx,al

       mov dx,ctl53
       mov al,00100101b
       out dx,al
       mov dx,t0
       mov al,10h
       out dx,al
       
       mov dx,ctl53
       mov al,01100111b
       out dx,al
       mov dx,t1
       mov al,10h
       out dx,al

 mov dx,ctl53
       mov al,10100111b
       out dx,al
       mov dx,t2
       mov al,50h
       out dx,al


       mov  cx,0ah
l1:    mov dx,in0
       out dx,al

l2:    call led
       mov dx,pc
       in al,dx
       test al,80h
       jnz l2
       
       mov dx,in0
       in al,dx
       mov dat,al
       mov dx,pb
       out dx,al

l3:    call led
       mov dx,pc
       in al,dx
       test al,80h
       jz l3
       call screen
       mov al,dat
       mov dx,pa
       out dx,al
       loop l1
       mov ah,4ch
       int 21h



screen proc near 
      push cx
      mov cl,4
      mov al,dat
      shr al,cl
      and al,0fh
      cmp al,0ah
      jc l7
      add al,07h
l7:  add al,30h
      mov dl,al
      mov ah,02h
      int 21h
      mov al,dat
      and al,0fh
      cmp al,0ah
      jc l8
      add al,07h
l8:   add al,30h
       mov dl,al
       mov ah,02h
       pop cx
       int 21h
       ret
screen endp



led proc near
      push cx
      mov cl,4
      mov al,dat
      and al,0f0h
      rol al,cl
      lea bx,table
      xlat
     
     mov dx,pb
     out dx,al
     
     mov dx,pc
     mov al,02h
     out dx,al
    
     mov al,0
     out dx,al
     
     mov al,0fch
     out dx,al
    
    mov al,dat          
    and al,0fh           ;取低4位
    lea bx,table
    xlat                 ;八段显示器译码
    
     mov dx,pb
     out dx,al            ;送数据至B口
    
     mov dx,pc
     mov al,01h           ;送低位位码0000001
     out dx,al
    
     mov al,0             ;送间隔
     out dx,al
     
     mov al,0fch
     out dx,al
     pop cx   

     ret
led endp
code ends
         end start