RE: [avr-libc-dev] wdt_enable may fail to enable the watchdogonATmega1281

[Weddington, Eric]

> -----Original Message-----
> From: 
> address@hidden 
> [mailto:address@hidden
> org] On Behalf Of Joerg Wunsch
> Sent: Monday, August 31, 2009 12:13 PM
> To: address@hidden
> Subject: Re: [avr-libc-dev] wdt_enable may fail to enable the 
> watchdogonATmega1281
> 
> As Weddington, Eric wrote:
> 
> > > Instructions such as sts that use two words (32 bits) are not
> > > guaranteed to be executed before an interrupt may fire.
> 
> > Have you tested this on the ATmega1281?
> 
> This behaviour would surprise me a bit, given that the datasheet
> chapter about interrupt latency explicitly mentions the increased
> latency when the interrupt arrives while a multiword instruction is
> currently being executed.
> 
> I'd be interested in setting up a test setup that experimentally
> verifies this behaviour, as the assumption the next instruction will
> still be executed without being interrupted is quite crucial to the
> toolchain.

Exactly. I'm interested to hear what the OP has to say about this.