UART ATMega64L

#include <avr/io.h>

#include <avr/interrupt.h>

//#include <avr/signal.h>

#include <inttypes.h>

#include <avr/delay.h>

//#include <avr/iom64.h>

ISR (USART1_RX_vect);

#define F_OSC 8000000               /* oscillator-frequency in Hz */

#define UART_BAUD_RATE 9600

#define UART_BAUD_CALC(UART_BAUD_RATE,F_OSC) ((F_OSC)/((UART_BAUD_RATE)*16l)-1)

void visableDelay(uint8_t cnt)

{

  uint8_t c;

  // avr/delay.h  _dealy_loop_2() which takes a

  // uint16_t as its argument

  // provides a delay determined by the argument, 

  // this delay varies with processor speed

  // the value is fixed at 0x8000 for an the 8 mhz cerebot

  for(c = 0; c < cnt; c++)

  {

    _delay_loop_2(0x8000);      

  }

}

void usart_putc(unsigned char c) {

   // wait until UDR ready

  while(!(UCSR1A & (1 << UDRE1)));

  UDR1 = c;    // send character

  return;

}

void init(void) {

  // set baud rate

  UBRR1H = (uint8_t)(UART_BAUD_CALC(UART_BAUD_RATE,F_OSC)>>8);

  UBRR1L = (uint8_t)UART_BAUD_CALC(UART_BAUD_RATE,F_OSC);

  UCSR1A = (1 << RXC1);

  // Enable receiver and transmitter; enable RX interrupt

  UCSR1B = (1 << RXEN1) | (1 << TXEN1) | (1 << RXCIE1);

  //asynchronous 8N1

  UCSR1C = (1 << UCSZ10) | (1 << UCSZ11) | (1 << UMSEL1); //| (1 << UCSZ00) | (1 << UCSZ11);

  return;

}

// INTERRUPT can be interrupted

// SIGNAL can't be interrupted

ISR (USART1_RX_vect) { // USART RX interrupt

  unsigned char c;

  PORTE &= ~(1 << PE6);

  c = UDR1;

  usart_putc(c);

  return;

}

int main(void) {

  DDRE = 0xf0;

  //PORTE |= (1 << PE6);

  init(); // init USART

    //PORTE |= (1 << PE6);

  sei();  // enable interrupts

  // send initial character

  while(!(UCSR1A & (1 << UDRE1)));

  UDR1 = 0x43; // "C"

  PORTE |= (1 << PE4);

  while(!(UCSR1A & (1 << UDRE1)));

  UDR1 = 0x0d;

  // enable  PD5 as output

  while (1) {

    // PIN5 PORTD clear -> LED off

    PORTE &= ~(1 << PE5);

    visableDelay(15);

    // PIN5 PORTD set -> LED on

    PORTE |= (1 << PE5);

    visableDelay(15);  

  }

  return 0;

}