OUTBIT   equ 08002h  ; 位控制口
OUTSEG   equ 08004h  ; 段控制口
IN       equ 08001h  ; 鍵盤讀入口

LEDBuf   equ   60h     ; 顯示緩沖
Num      equ   70h     ; 顯示的數據
DelayT   equ   75h     ;
       ljmp  Start

LEDMAP:              ; 八段管顯示碼
       db    3fh, 06h, 5bh, 4fh, 66h, 6dh, 7dh, 07h
       db    7fh, 6fh, 77h, 7ch, 39h, 5eh, 79h, 71h

Delay:               ; 延時子程序
       mov   r7, #0
DelayLoop:
       djnz  r7, DelayLoop
       djnz  r6, DelayLoop
       ret

DisplayLED:
       mov   r0, #LEDBuf
       mov   r1, #6          ; 共6個八段管
       mov   r2, #00100000b  ; 從左邊開始顯示
Loop:
       mov   dptr, #OUTBIT
       mov   a, #0
       movx  @dptr, a        ; 關所有八段管

       mov   a, @r0
       mov   dptr, #OUTSEG
       movx  @dptr,a
       mov   dptr, #OUTBIT
       mov   a, r2
       movx  @dptr, a        ; 顯示一位八段管

       mov   r6, #01
       call  Delay

       mov   a, r2           ; 顯示下一位
       rr    a
       mov   r2, a

       inc   r0

       djnz  r1, Loop

       mov   dptr, #OUTBIT
       mov   a, #0
       movx  @dptr, a        ; 關所有八段管
       ret


Start:
       mov   sp, #40h
       mov   Num, #0
MLoop:
       inc   Num
       mov   a, Num
       mov   b, a
       mov   r0, #LEDBuf
FillBuf:
       mov   a, b
       anl   a, #0fh
       mov   dptr, #LEDMap
       movc  a, @a+dptr    ; 數字轉換成顯示碼
       mov   @r0,a         ; 顯示在碼填入顯示緩沖
       inc   r0
       inc   b
       cjne  r0, #LEDBuf+6, FillBuf

       mov   DelayT,#30
DispAgain:
       call  DisplayLED    ; 顯示
       djnz  DelayT,DispAgain

       ljmp  MLoop

       end