11.asm

8255LED实验的代码

　 data    segment

data1   db 'traficlight system','$'

data    ends

code    segment

        assume cs:code,ds:data

start:  mov ax,data

        mov ds,ax

        lea dx,data1

        mov ah,09h

        int 21h

        mov dx,21bh

        mov al,10000010b

        out dx,al

        mov dx,219h

        in al,dx

        mov bl,al

        mov dx,21bh

        mov al,10000000b

        out dx,al

        mov dx,219h

        mov al,0ffh

        out dx,al

        mov dx,21ah

        mov al,0f0h

        out dx,al

        call delay1

l1:     mov al,10100101b

        out dx,al

        call delay1

        mov al,0f5h

        out dx,al

        call loop1

l3:     mov dx,21ah

        mov al,5ah

        out dx,al

        call delay1

        

        

        

        mov al,0fah

        out dx,al

        call loop2

        mov dx,21ah

        mov al,11111111b

        out dx,al

        mov ah,0bh

        int 21h

        cmp al,00h

        je l1

l7:     mov ah,4ch

        int 21h

delay   proc

        mov ah,0bh

        int 21h

        cmp al,00h

        jne l7

        mov cx,2000h

l4:     push cx

        mov cx,2000

l5:     loop l5

        pop cx

        loop l4

        ret

delay   endp

loop1   proc

        mov ah,0bh

        int 21h

        cmp al,00h

        jne l7

        mov cx,8

l6:     mov dx,219h

        mov al,10101111b

        out dx,al

        push cx

        call delay

        pop cx

        mov al,0ffh

        out dx,al

        push cx

        call delay

        pop cx

        loop l6

        ret

loop1   endp

loop2   proc

        mov ah,0bh

        int 21h

        cmp al,00h

        jne l7

        mov cx,8

l9:     mov dx,219h

        mov al,5fh

        out dx,al

        push cx

        call delay

        pop cx

        mov al,0ffh

        out dx,al

        push cx

        call delay

        pop cx

        loop l9

        ret

loop2   endp

delay1  proc

        mov cx,10

l8:     push cx

        call delay

        pop cx

        loop l8

        ret

delay1  endp

code    ends

        end start