#include <avr/io.h>
 
int main( void )
{
    short i;

    DDRB |= 1 << DDB6;
    PORTB |= 1 << PB6;
    PORTB &= ~( 1 << PB6 );

    while ( 1 ) {
        for ( i = 0; i < 10000; i++ );
	PORTB ^= 1 << PB6;
    }

    return 0;
}