rdout.asm

1

#INCLUDE <P16f877a.INC>

COUNT    EQU  0X20 
COUNT1   EQU  0x21
COUNT2   EQU  0x22
#DEFINE   IOX   PORTD
#DEFINE   TIOX  TRISD

ORG 0X0;
NOP
GOTO MAIN


ORG 0X30
MAIN;流水灯,RD口
  
 
  BSF   STATUS,RP0;  
  CLRF  TIOX;
  BCF	TRISE,PSPMODE;		必须关闭从并行端口模式
  BCF   STATUS,RP0;
  
  
  MOVLW 0X01
  MOVWF IOX;
  NOP
  CALL DELAY;

  MOVLW 0X02
  MOVWF IOX;
  NOP
  CALL DELAY;

  MOVLW 0X04
  MOVWF IOX;
  NOP
  CALL DELAY;

  MOVLW 0X08
  MOVWF IOX;
  NOP
  CALL DELAY;

  MOVLW 0X10;
  MOVWF IOX;
  NOP
  CALL DELAY;
  
 
  MOVLW 0X20
  MOVWF IOX;
  NOP;          
  CALL DELAY; 

  MOVLW 0X40
  MOVWF IOX;
  NOP;          
  CALL DELAY; 

  MOVLW 0X80
  MOVWF IOX;
  NOP;          
  CALL DELAY; 



  GOTO  MAIN;

DELAY                  ; 0.5s延时子程序		
	clrf	COUNT      ;
	clrf	COUNT1     ; 
	movlw	0x03       ; 
	movwf	COUNT2     ; 
LDloop		
	decfsz	COUNT,f    ; 
	goto	LDloop     ; 
	decfsz	COUNT1,f
	goto	LDloop
	decfsz	COUNT2,f
	goto	LDloop
	return
	
	END