display.txt

在Keil里面编写的可以运行于80C51单片机上的计算器程序。可以实现简单的加减乘除运算。

        ORG    0000H
	AJMP   START
	ORG    0030H
START:  
        MOV    48H,  #01
	MOV    49H,  #02
	MOV    4AH,  #03
	MOV    4BH,  #04
     DD:ACALL   DISPLAY
        AJMP    DD
DISPLAY:MOV     R5,  #04H
        MOV    R2,  #01H
        MOV     R0,  #48H
  DISP1:MOV     DPTR,#8FFFH
        MOV     A,   R2 
	MOVX    @DPTR,A
	MOV     A,   @R0
  DISP2:MOV     DPTR,#SHOWTABLE
        MOVC    A,   @A+DPTR
	MOV     DPTR,#9FFFH
	MOVX    @DPTR,A
	ACALL   DEL0
	MOV     A,   R2
	RL      A
	MOV     R2,  A
	INC     R0
	DJNZ    R5,  DISP1
      RET
SHOWTABLE:
        DB   3FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,6FH
  DEL0: MOV     R6,  #00H
    TM: MOV     R7,  #01H
        DJNZ    R7,  $
	DJNZ    R6,  TM
      RETI
    END