Posted on May 17, 2011 at 13:00Hello,
I've seen this behaviour when using the IWDG: if you refresh it continously, it doesn't work properly, even if you're checking first the IWDG_SR_RVU flag.
My testing program is just:
Code:
IWDG_Init()
while(1)
{
if( IWDG_GetFlagStatus(IWDG_FLAG_PVU) == RESET )
{
IWDG_ReloadCounter();
}
}
then I shortcircuit my external oscillator for a WD_RELOAD_TIME and expect that the micro will be reset. But it never happens.
In contrast, if I use a timer to ensure a minimum time between refreshes, it works as expected and the micro is reset when you stop the external oscillator.
Code:
// WDtimer is a msec counter updated in systick interrupt
while(1)
{
if( WDtimer > (WD_RELOAD_TIME / 5) )
{
IWDG_ReloadCounter();
WDtimer=0;
}
}
Maybe I have to look it thoroughly, but I haven't seen any explication to this behaviour in the Ref. Manual.
