AtMega32: Aufwachen aus Powerdown FAIL

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ISR(INT0_vect) {

}

int main(){

  GICR   |= (1<<INT0); // Enable INT0

  MCUCR  |= (1<<ISC01) | (1<<ISC00); // INTO set for rising edge

        DDRD  |= (0<<PD2); // Buttonpin set as input

  sei();    // Enable global interrupts

  while(1){    

    GICR |= (1<<INT0);

    if(led_index == 14){

      set_sleep_mode(SLEEP_MODE_PWR_DOWN);

      sleep_mode();      

    }

    GICR &= ~(1 << INT0);

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  }

}