numprocess.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   20H, #00H
      MOV   21H, #01H
      MOV   22H, #05H
      ACALL MUNPROCESS
   


MUNPROCESS:
      MOV   A, 20H
      JZ    BCD1
 BCD2:MOV   A, 21H
      CJNE  A, #2, BCD2IN
      AJMP  RETURN 
BCD2IN:MOV  37H, 36H
      MOV   36H, 22H
      INC   21H
      MOV   48H, 30H
      MOV   49H, 31H
      AJMP  RETURN
 BCD1:MOV   A, 21H
      CJNE  A, #2, BCD1IN
      AJMP  RETURN
BCD1IN:MOV  31H, 30H
      MOV   30H, 22H
      INC   21H
      MOV   48H, 30H
      MOV   49H, 31H
RETURN:RET
     
  END