AVR Freaks

Hi,

I am trying to debug my ATmega324P TQFP INT0 interrupt.  I have configured the MCU so INT0 (PD2)  is triggered on an incoming logic low event and therefore I have used a pull-up resistor.  

The problem I have is the INT0 I/O pin after the first event is pulled low and will not reset high.  I have confirmed this by putting a scope on the I/O pin.

I have included my code below, and cross referenced with the datasheet, but I do not think I have made a mistake.  Can anybody see any problem, or am I implementing my interrupt incorrectly?

Thanks,

Tuurbo46

#define F_CPU 8000000UL  
#include <avr/io.h>
#include <util/delay.h>
#include <stdio.h>
#include <avr/interrupt.h>

 

int8_t Data;

 

ISR(INT0_vect) 
{            
    Data = 1;
}

 

int main(void)
{

DDRB = (1 << DDRB4);    // Set LED as output
PORTB = 0b00000000;     // Set LED state to zero

 

DDRD =  (0 << DDRD2);   // Set INT0 as input
PORTD = (1 << PORTD2);  // Set INT0 pull up resistor
        
EIMSK |= (1 << INT0);                              // Enable INT0                          
EICRA |= (0 << ISC01) | (0 << ISC00 );   // Trigger on logic low
sei();
     
     while(1)
     {
         if (Data)             
         {
              Data = 0;
                                            
              PORTB ^= PORTB4;  // Toggle led state
                                          
         }
     }
}