Question

请问以下有关单片机跑马灯的C语言程序各语句的含义（详细）

#include <reg51.h>
#include <intrins.h>
void Delay10ms(unsigned int c);

void main(void)
{
unsigned char LED;

LED = 0x01;

while(1)
{
P0 = LED;

Delay10ms(50);

LED = _crol_(LED,1);
}
}

void Delay10ms(unsigned int c)
{
unsigned char a, b;

for (;c>0;c--)
{
for (b=38;b>0;b--)
{
for (a=130;a>0;a--);
}
}
}

Answer 1

#include <reg51.h> //51头文件
#include <intrins.h> //包含移位函数_crol_
void Delay10ms(unsigned int c); //延时函数声明

void main(void)
{
unsigned char LED;

LED = 0x01; //一个unsigned char有8位，每一位代表了一个灯，初始点亮第一盏灯
while(1)
{
P0 = LED; //点亮一盏灯

Delay10ms(50); //延时500ms，让其量一会儿

LED = _crol_(LED,1); //向左移位函数，比如 0x01 --> 0x02 --> 0x04 -->0x08 ---> 0x10
}
}

void Delay10ms(unsigned int c) //延时函数
{
unsigned char a, b;

for (;c>0;c--) //三重循环延时，大约延时10ms
{
for (b=38;b>0;b--)
{
for (a=130;a>0;a--);
}
}
}