51单片机之流水灯，循环位移函数

先介绍循环位移函数

#include <reg52.h>
#include <intrins.h>  //还需要引入这个头文件

// 字符型循环左移：_crol_
//字符型循环右移：_cror_
void test1()
{
    unsigned char a;
    unsigned char b;
    unsigned char c;
    unsigned char d;
    unsigned char e;
    a = 0xfe;  //1111 1110
    b = _crol_(a, 1);  //1111 1101 
    c = _crol_(a, 2);  //1111 1011

    d = _cror_(a, 1);  //0111 1111
    e = _cror_(a, 2);  //1011 1111
}

// 注意对比位移运算符
void test2()
{
    unsigned char a;
    unsigned char b;
    unsigned char c;
   
    a = 0xfe;  //1111 1110
    b = a << 1;  //1111 1100  右边自动补0 
    c = a >> 1;  //0111 1111   左边自动补0
}

流水灯代码

#include <reg52.h>
#include <intrins.h>  //还需要引入这个头文件
#define uint unsigned int
#define uchar unsigned char

void delay(unsigned int z)
{
    unsigned int x, y;
    for(x = z; x > 0; x--)
        for(y = 114; y >0; y--);
}

void main()
{
    //变量初始化
    uchar temp;
    temp = 0xfe;
    P1 = temp;
    delay(100);
    while(1)
    {
        temp = _crol_(temp, 1);
        P1 = temp;
        delay(100);
    }
}