#include "iom16v.h"  

//延時(shí)函數(shù)
//在16MHz時(shí)產(chǎn)生ms=2000時(shí)產(chǎn)生1ms的延時(shí)
void s_ms(unsigned int ms)
{
	for(;ms>1;ms--);
}	
 
main()
 {
 DDRD=0xff;
 //在端口d產(chǎn)生500Hz的信號(hào)
 while(1)
   {
   PORTD=0xff;
   s_ms(1000);
   PORTD=0x00;
   s_ms(1000);
   }
 }