#include<reg51.h>
#define uint unsigned int
#define uchar unsigned char
//sbit A=P1^0;
//sbit B=P1^1;
//sbit C=P1^2;
//sbit D=P1^3;
uchar table[]={
0xfe,0xfd,0xfb,0xf7
};
uchar num;
void delay(uint z)
{
	uint x,y;
		for(x=z;x>0;x--)
			for(y=110;y>0;y--);
}
void main()
{
	num=0;
	while(1)
		{
			for(num=0;num<4;num++)
				{
					P1=table[num];
					delay(2);
				}
			for(num=4;num>0;num--)
				{
					P0=table[num];
					delay(3);
				}
		}
}