main.c

从零开始学51单片机源代码

//main.c
#include <reg51.h>	//包含头文件

 //定义端口寄存器
sfr P0M0 = 0X93;
sfr P0M1 = 0X94;
sfr P1M0 = 0X91;
sfr P1M1 = 0X92;
sfr P2M0 = 0X95;
sfr P2M1 = 0X96;  
sfr P3M0 = 0Xb1;
sfr P3M1 = 0Xb2;    

//定义延时函数
void ms_delay(unsigned int t)
{
	unsigned  int  i;
	for (t; t > 0; t--)	//外层循环t次	 
		for (i = 110;i > 0; i--)	//内层循环110次		   
		;
}  

main()
{
	int num = 0;

	//配置端口模式 
	P1M1 = 0x00;
	P1M0 = 0x00;   
	
	P1 = 0xff;	//P1.0 - P1.2部关闭	
	while(1)
	{
	 	switch (num)
		{
			case 0:	
				P1 = 0xff;	//P1.0 - P1.2全部关闭	
				break;
			case 1:
				P1 = 0xfe;	//打开P1.0	1111 1110
				break;
			case 2:
				P1 = 0xfd;	//打开P1.1 1111 1101
				break;
			case 3:
				P1 = 0xfc;	//打开P1.0、P1.1	1111 1100
				break;
			case 4:
				P1 = 0xfb;	//打开P1.2
				break;
			case 5:
				P1 = 0xfa;	//打开P1.2和P1.0
				break;
			case 6:
				P1 = 0xf9;	//打开P1.2和P1.1
				break;
			case 7:
				P1 = 0xf8;	//全开 
				break;
			default:	
				P1 = 0xff;	//P0.0 - P0.2全部关闭	
		}
		ms_delay(1000);
		num ++;
		if (num > 7)
			num = 0;	
	}
}