unsigned char HN, LN;
unsigned char swap;
void setup() {
  DDRA= 0x00;
  DDRC= 0xFF;
}

void loop() {
  PINA= 0x34;
  LN= PINA & 0x0F;
  HN= PINA & 0xF0;
  HN= HN>>4;
  LN= LN<<4;
  PORTC= HN | LN;
}