Testing external interrupt INT0 on tiny13

Tiny 13 have an external interrupt "INT0" on PB1, We have created a test project on avr-gcc to have a quick testing on the INT0.

#include <avr/io.h>
#include <avr/interrupt.h>
#include "pin_macros.h"

unsigned char led=0;

ISR(INT0_vect) {
     if (led){
             b0_high;
             led = 0;
     } else {
             b0_low;
             led = 1;
     }
}

int main (void)
{
     b1_input; //switch
     b0_output; //led output

     MCUCR = 1<<isc01; //set INT0 as falling edge trigger

     GIMSK = 1<<INT0; //enable INTO in global interrupt mask


     sei(); //enable interrupt

     while(1) {
              ;; //interrupt do the rest
     }
}

B1 is connected to a switch, and B0 is connected to a LED.
When B1 is pressed, it would toggle the LED On or Off.

Download the whole project : http://labs.bitartist.org/test_int0.tar.gz

Reference:
http://www.nongnu.org/avr-libc/user-manual/group__avr__interrupts.html