3-2.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
      TABLE  db    10 dup(?)
      NUM    db    10
data ends

code segment 
   assume cs:code,ds:data
start:
      mov    dx,ctl53
      mov    al,00100101B
      out    dx,al
      mov    dx,T0
      mov    al,10H
      out    dx,al
      mov    dx,ctl53
      mov    al,01100101B
      out    dx,al
      mov    dx,T1
      mov    al,10H
      out    dx,al  
 
      mov     dx,ctl55
      mov     al,10011000B
      out     dx,al
      mov     dx,PC
  L0: in      al,dx
      test    al,80H
      jz      L0
      mov     dx,PA
      in      al,dx
      mov     dx,PB
      out     dx,al
      lea     bx,TABLE
      mov     [bx],al
      inc     bx
      mov     dx,PC
   L1:in      al,dx
      test    al,80H
      jz      L1
      dec     NUM
      cmp     NUM,00H
      jnz     L0
      mov     ah,4cH
      int     21H
code ends
      end  start