[avr-gcc-list] Interrupt handling

[Kreyl Laurelindo]

Hi!

   Writing asm codes, I usually used things like this:

============
...
.org 0x09
reti         ; Timer0 overflow handler

...

; in main function:
...
_start:
        sei
        sleep   ; enter sleep mode

        ; do smth
rjmp _start

===========

   E.g.,  I  did  not  need  anything  else from that "Timer0 overflow
interrupt  handler"  than just awake from sleep mode. Now, I tried use
the same in c:

==========
...
void init (void)
{
   ... //setup timers, sleep mode, usart, etc.
}

void main (void)
{
   init();
   while(1)
   {
      usart_send('1');
      sei();
      sleep();
      usart_send('2');
      ... // do something
   }
}

SIGNAL (SIG_OVERFLOW0)
        ;

==============

So,  if  this  would  work  as I want, I would see '1' and then '2' at
terminal  window.  But I see only '1', as if 'while' loop begins again
after awake (not next instruction, as in aseembly). So, I decided I do
not understand something in interrupts realisation.

I tried 'asm volatile ("nop"::);' instead of just ';', and this had no
effect, too.

Maybe, things of such type would be realised in other way? I just want
to wake after sleep :-) with no need of special interrupt routines.


                                                Kreyl