#include <io.h>
#include <signal.h>
#include <interrupt.h>


#define SYSCLK		16000000
#define BAUD		9600UL
#define UBRR_BAUD	((SYSCLK/(16*BAUD))-1)


uint8_t timerflag = 0;
volatile uint8_t LTIMER = 0;
volatile uint8_t HTIMER = 0;


int main()
{

	PORTD |= (1<<PD2);
	
	// UART
	UBRRH = (unsigned char) (UBRR_BAUD>>8);									
	UBRRL = (unsigned char) UBRR_BAUD;
	UCSRB = (1<<RXCIE)|(1<<RXEN)|(1<<TXEN);									
	UCSRC = (1<<URSEL)|(1<<UCSZ1)|(1<<UCSZ0);	

	//Interrupts
	MCUCR |= (1<<ISC01) | (1<<ISC00);										
	GICR &= ~(1<<INT0);
																
	// Timer
	TCNT1H = 0;																
	TCNT1L = 0;																
   	TIMSK |= (1<<TOIE1);  
   	TCCR1A = 0;
	TCCR1B = 0b00000000;


	sei();


	while(1){																


	if (LTIMER > 0){		
		while ( !( UCSRA & (1<<UDRE)) );
		UDR = HTIMER;
		while ( !( UCSRA & (1<<UDRE)) );
		UDR = LTIMER;
		HTIMER = 0;
		LTIMER = 0;
	}		

	}

return 0;
}



SIGNAL (SIG_INTERRUPT0)
{ 
													
	uint8_t tmp_sreg;  
    	tmp_sreg = SREG;   
    	cli();             

	if (timerflag == 0) {													
		TCCR1B = 0b00000101;	
		timerflag = 1;
	} else {
		TCCR1B = 0b00000000;
		LTIMER = TCNT1L;
		HTIMER = TCNT1H;
		TCNT1H = 0;	
		TCNT1L = 0;															
		GICR &= ~(1<<INT0);													
		timerflag = 0;	
	}


	SREG = tmp_sreg;     
}


SIGNAL(SIG_UART_RECV)														
{
	uint8_t tmp_sreg;  
    	tmp_sreg = SREG;   
    	cli();  
          
	unsigned char buffer;															
	buffer = UDR;
	while ( !( UCSRA & (1<<UDRE)) );										
	UDR = buffer;

	TCNT1H = 0;																
	TCNT1L = 0;																
	GIFR |= (1<<INTF0);
	GICR |= (1<<INT0);
		
	SREG = tmp_sreg	;														
}