#include <avr/interrupt.h>
#include <avr/signal.h>
#include <avr/pgmspace.h> 
#include <avr/delay.h>
#include <inttypes.h>

SIGNAL(SIG_UART_RECV)
{
	uint8_t data;
	// copy the UDR into portB
	data=inp(UDR);
	outp(~data,PORTB);
}
void UARTInit(void)
{
        // Initializing UART:
        outp(BV(RXCIE)|BV(TXCIE)|BV(RXEN)|BV(TXEN),UCR); 
        // Setting the control register
        outp(0x17, UBRR);  //Baudrate 9600 with onboard 
                           //oscillator at 3.68MHz 
        sei(); // enabling global interrupts
}

int main(void)
{
	outp(255,DDRB);
        UARTInit();  
	while(1);
}