Uart mit Interrupt

#include <avr/io.h>

#include <avr/interrupt.h>

#include <util/delay.h>

#define F_CPU 20000000UL

#define  Led_GR_HI  PORTB|=(1<<PB0)

#define  Led_GR_LOW  PORTB&=~(1<<PB0)

#define  Led_RO_HI  PORTB|=(1<<PB5)

#define  Led_RO_LOW  PORTB&=~(1<<PB5)

void Port_Init()

{

  DDRB|=(1<<PB0)|(1<<PB5);

}

unsigned char RxData;

void UART_Init(void)

{

  UCSR0B|=(1<<RXEN0)|(1<<TXEN0)|(1<<RXCIE0); // Sender, Empfaenger, Interrupt ein

  UCSR0C|=(1<<UCSZ01)|(1<<UCSZ00); // Asynchron 8N1

  UBRR0H = 0;  // Aus dem Datenblatt fuer 19,2 kBaud

  UBRR0L = 64; // Aus dem Datenblatt

} 

ISR(USART_RX_vect) // Vector aus dem iomx8.h    

{

//  while ( !( UCSR0A & (1<<RXC0)) );  

  RxData = UDR0;

}

int main(void)

{

  Port_Init();

  UART_Init();

  sei();

  if(RxData == 0x01)

  {

    Led_GR_HI;

    _delay_ms(100);

  };

  Led_GR_LOW;

  if(RxData == 0x02)

  {

    Led_RO_HI;

    _delay_ms(100);

  };

  Led_RO_LOW;

  while(1);  

}