RTC_init() will only work in setup() , loop forever if run in main()

[cpainchaud]

void RTC_init()
{
  /* Initialize RTC: */
  while (RTC.STATUS > 0  )
  {
    ;                                 /* Wait for all register to be synchronized */
  }
  RTC.CLKSEL = RTC_CLKSEL_INT1K_gc;   

  RTC.PITINTCTRL = RTC_PI_bm;           /* PIT Interrupt: enabled */

  RTC.PITCTRLA = RTC_PERIOD_CYC4096_gc 
                 | RTC_PITEN_bm;
}

while (RTC.STATUS > 0) is never ending loop when RTC_init() is run from main() instead of setup();

[cpainchaud]

I guess both options should be given but for sure it's now clear that RTC based one will be way more flexible.

[cpainchaud]

one last question: while (RTC.STATUS > 0 ); this will wait for registers sync. Does it happen at CPU clock timing or RTC/PIT clock timing? I am trying to evaluate the potential lag introduced by this statement which cannot be avoided (going to sleep before waiting for this sync to happen will make CPU sleep forever)

[SpenceKonde]

It's like all the rest of the 2-flipflop-synchronizers; it's clocked ffrom CLK_RTC; Takes 2-3 (depending on where in the clock the input changes state) RTC clocks.

[SpenceKonde]

Closing - no defect in core. Feel free to open issue if there are further problems - though consider using discussion if the matter at hand appears to be the weird behavior of the chip itself, as opposed to the core.