#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);
}
}
}