[avr-gcc-list] lack of interruption

[jeffrey traer bernstein]

can't quite figure out why my interrupt isn't interrupting... anybody
have any suggestions?

it's on an atmega16



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

void SIGNAL( SIG_OVERFLOW0 )
{
    PORTA = 0x00;
}


int main()
{
  DDRA = 0xff;
  PORTA = 0x01;  

  TIMSK = _BV(TOIE0);
  TCCR0 = 0x05;
  TCNT0 = 0;

  sei();

  while ( 1 );

  return 0;
}