#include <avr\io.h>    
  #include <avr\interrupt.h>
  
  isr(usart_udre_vect)
  {
     udr = 'g' ;
  }
  
  int main (void)
  {
    ucsrb = (1<<txen)|(1<<udrie) ;              
    ucsrc = (1<< ucsz1)|(1<<ucsz0)|(1<<ursel);
    ubrrl = 0x33 ;
  
    sei();        
  
    while (1);      
  
    return 0 ;
  }