led.asm

一个双字点阵的程序,能实现左右移动的功能.

         ORG    00H
MOVE:    MOV    20H,#00H;代码暂存地址为20H
         MOV    R4,#00H;74154扫描指针初值
M1:      MOV    R1,#0fH;每幕停留时间
M2:      MOV    R6,#32;每幕32个数据
         MOV    R0,20H;取码指针存入R0
M3:      CALL   READ1
         INC    R4;扫描下一行
         DJNZ   R6,M3;是否显示完一幕?
         MOV    R4,#00h;清除74154扫描指针
         DJNZ   R1,M2;每幕停留时间到了吗?
         MOV    A,20H
         ADD    A,#08
         MOV    20H,A
         xrl	a,#0ffh;8个字是否左移完毕?
         JNZ    M1

READ1:   MOV    P1,R4;扫描指针载入
       
         MOV    A,R0;取码指针载入A
         MOV    DPTR,#TAB;数据指针到TAB
         MOVC   A,@A+DPTR;到TAB取上半部的数据码
         MOV    P0,A
         INC    R0
         MOV    A,R0
         MOV    DPTR,#TAB;数据指针到TAB
         MOVC   A,@A+DPTR;到TAB取下半部数据码
         MOV    P2,A
         INC    R0
         MOV    R3,#0ffh;延时
         DJNZ   R3,$
         MOV    A,#00H
         MOV    P0,A
         MOV    P2,A
         RET
TAB:	DB 00h,00h,00h,00h,0F8h,7Fh,08h,21h,08h,21h,0Ch,21h,0Bh,21h,08h,21h ; 
	DB 08h,21h,08h,21h,08h,21h,08h,21h,0F8h,7Fh,00h,00h,00h,00h,00h,00h ; "白" 0

	DB 40h,00h,40h,20h,44h,70h,44h,38h,44h,2Ch,44h,27h,0C4h,23h,0C4h,31h ; 
	DB 44h,10h,44h,12h,46h,14h,46h,18h,64h,70h,60h,20h,40h,00h,00h,00h ; "云" 1
  	END