#include<reg52.h>

sbit ADDR0 = P1^0;

sbit ADDR1 = P1^1;

sbit ADDR2 = P1^2;

sbit ADDR3 = P1^3;

sbit ENLED = P1^4;

void main()

{

unsigned char cnt = 0;

unsigned int i=0;

ENLED = 0;

ADDR3 = 1;

ADDR2 = 1;

ADDR1 = 1;

ADDR0 = 0;

while(1)

{

P0 = ~(0x7F>>cnt);

for(i=0; i<30000; i++);

cnt++;

if(cnt>=8)

{

cnt = 0;

}

}

}