学习单片机第5天

#include"reg52.h"
#include"intrins.h"

#define GPIO_LED P0
typedef unsigned char u8;
typedef unsigned int u16;

sbit IN_PL=P1^6;
sbit IN_Data=P1^7;
sbit SCK=P3^6;//clock


u8 Read74HC165(){
	//programm according to Sequence Diagram
	u8 indata;
	u8 i;
	IN_PL=0;
	_nop_();//短暂延时产生一定宽度的脉冲
	IN_PL=1;//将外部信号全部读入锁存器中
	_nop_();
	indata=0;//保存数据的变量清0
	
	for(i=0;i<8;i++){
		indata=indata<<1; //左移一位
		SCK=0;//时钟置0
		_nop_();
		indata|=IN_Data;
		SCK=1; //时钟置1
	}
	return indata;
}

void main(){
	u8 h165Value;
	while(1){
		h165Value=Read74HC165();
		if(h165Value!=0xff){
			GPIO_LED=h165Value;
		}		
	}
}