STC89C52单片机实现LED流水灯

#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;  //1111 1110
    Delay500ms();
    P2=0xFD;  //1111 1101
    Delay500ms();
    P2=0xFB;  //1111 1011
    Delay500ms();
    P2=0xF7;  //1111 0111
    Delay500ms();
    P2=0xEF;  //1110 1111
    Delay500ms();
    P2=0xDF;  //1101 1111
    Delay500ms();
    P2=0xBF;  //1011 1111
    Delay500ms();
    P2=0x7F;  //0111 1111
    Delay500ms();
  }
}