smg3.asm

51单片机开发入门与典型实例

;程序：SMG3.ASM    
   START:   MOV    R0, #0                               
            MOV    DPTR, #TABLE 
   LOOP:    ACALL  DISPLAY      
            INC     R0                 
	    CJNE   R0,#100,LOOP    
	    JMP    START                             
  DISPLAY:  MOV    A,R0               
            MOV    B, #10    
              DIV     AB   
            MOV    R1, A    
            MOV    R2, B      
            MOV    R3, #50    
  LOOP1:    MOV    A,  R2  
            ACALL  CHANG                                   
	    CLR     P2.0        
            ACALL  DLY10mS
            SETB    P2.0       
            MOV    A, R1      
            ACALL  CHANG                                   
            CLR     P2.1      
            ACALL  DLY10mS 
            SETB   P2.1       
            DJNZ  R3,LOOP1  
            RET               
 CHANG:     MOVC  A,@A+DPTR
            MOV   P0,A                 
            RET              
  DLY10mS:  mov   r6,#20      
   D1:      MOV   R7,#248   
            DJNZ    R7, $       
	    DJNZ    R6, D1                           
            RET                    
 TABLE:     DB  0C0H,0F9H,0A4H,0B0H
            DB  99H,  92H,  82H,  0F8H  
            DB  80H,  90H,  88H,   83H  
            DB  0C6H, 0A1H,  86H,  8EH                      
            END