#include "iom128v.h"
void Delay(unsigned int span)//延時1ms，f=4MHz
{
 	 unsigned char i;
	 
	 TCCR0=0x03; 	//32分頻計時
	 
	 //span=3*span;
	 
	 TIMSK=0x01; 		//開中斷
	 //TCNT0=0;
  while(span>0)
  {
   TCNT0=131;
   while((TIFR&0x01)!=0x01)
   ;
   TIFR=0x01;
   span=span-1;	
  }
}