/*-----------------------------------------------------------------------
延時函數(shù)
系統(tǒng)時鐘：8M
-----------------------------------------------------------------------*/
void delay_1us(void)                 //1us延時函數(shù)
  {
   int d=1;
   //asm("nop");
  }
void delay_nus(unsigned int n)       //N us延時函數(shù)
  {
   unsigned int i=0;
   for (i=0;i<n;i++)
   delay_1us();
  } 
void delay_1ms(void)                 //1ms延時函數(shù)
  {
   unsigned int i;
   for (i=0;i<1140;i++);
  } 
void delay_nms(unsigned int n)       //N ms延時函數(shù)
{
   unsigned int i=0;
   for (i=0;i<n;i++)
   delay_1ms();
}