#include <avr/io.h>
#include <stdio.h>
#include <avr/interrupt.h>
unsigned char count=0;
void init_devices(void)
{
  cli();
  PORTD |= 0x01;   	// Switch PullUp 
	DDRD &= (~0x01);	// PORTD PD0 Input Port
	PORTL = 0x00;		// PORTL (PORTL LED)
	DDRL  = 0xff;		// PORTL Output Port
	// External Interrupt 0 ,Falling edge between two samples of INTn
	EICRA = (1<< ISC10);
	// External Interrupt 0 enable
	EIMSK |= (1 << INT0);
  sei();
}


int main(void)
{	init_devices();
	while(1){	
}
}
// External Interrupt

ISR (INT0_vect)
{
	EIMSK &= ~(1 << INT0);  	// External Interrupt 0 Disable
	count++;        		// count 
	// PORTL = count;  		// count LED
  PORTL = ~PORTL;
	EIFR |= (1 << INTF0);	// Clear External Interrupt Flag
	EIMSK |= (1 << INT0);              	// External Interrupt 0 enable
}