2/1.c

#include<reg52.h>
sbit LED1 = P2^0;
sbit LED2 = P2^1;
sbit LED3 = P2^2;
sbit LED4 = P2^3;
sbit LED5 = P2^4;
sbit LED6 = P2^5;
sbit LED7 = P2^6;
sbit LED8 = P2^7;
unsigned char i;
void main(){
	TMOD = 0x01;//T0 fangshi 1 dingshi
	TR0 = 1;//qidong
	i = 10;
	P2 = 0xF0;
	while(1){
		TH0 = 15536/256;//gaobawei chuzhi
		TL0 = 15536%256;//dibawei  chuzhi
		while(TF0 == 0);//waiting for yichu
		TF0 = 0;//TF ruanjianqingling
		i--;//yigezhouqishi 100ms   xitongshizhong 6MHZ
		if (i==0){
			P2 = ~P2;//qufan
			i = 10;
		}
	}
}