#include <REGX52.H>
#include <INTRINS.H>

void Delay500ms()    //@12.000MHz
{
  unsigned char i, j, k;

  _nop_();
  i = 4;
  j = 205;
  k = 187;
  do
  {
    do
    {
      while (--k);
    } while (--j);
  } while (--i);
}

void main()
{
  while(1)
  {
    P2 = 0xFE;
    Delay500ms();
    P2 = 0xFF;
    Delay500ms();
  }
}