
#include <REGX51.H>
typedef unsigned int u16;
typedef unsigned char u8;
u8 i=0;
void delay_10us(u16 t)
{
while(t--);
}
void main()
{
P2=~0x01;
while(1)
{
if(P3_1==0)
{
delay_10us(50000);
while(P3_1==0)
delay_10us(50000);
i++;
if(i>=8)
i=0;
P2=~(0x01<<i);
}
if(P3_0==0)
{
delay_10us(50000);
while(P3_1==0)
delay_10us(50000);
if(i==0)
i=7;
else
i--;
P2=~(0x01<<i);
}
}
}