Lpc2000

You are right, Brendan, Jim. I just tested and the watchdog, once 
triggered, won't trigger again until it is set up again. So I will 
use the watchdog with a pretty short timer (minimum = 0xff) and then 
enter an endless "enter idle mode" loop. It looks like interrupts can 
take you out of idle mode even if they are disabled.

Thank you all.

Guille

--- In lpc2000@yahoogroups.com, "brendanmurphy37" 
<brendan.murphy@i...> wrote:
>
> 
> Hi,
> 
> The watchdog, if it underflows, does a reset of the system. 
According 
> to the manual (I'm looking at the LPC213x User Manual), and I see 
no 
> reason to doubt it, there's very few differences between an 
internal 
> (watchdog) reset and an external (reset pin) reset.
> 
> The watchdog mode register description in tne same manual shows 
that 
> the reset value of the enabled flags is 0 (i.e. not enabled). I'd 
> take that to mean that there's no danger of what you're concerned 
> about (i.e. an infinite loop of watchdog resets).
> 
> Bottom line: if you trust the manual contents, it should be OK for 
> your purposes (indeed, I hope that it is, as it's exactly what we 
do 
> for a "soft" reset). As you point out, attempting to do it in 
> software can get messy very fast, if you want something general 
> purpose.
> 
> Regards
> Brendan
> 
> --- In lpc2000@yahoogroups.com, "Guillermo Prandi" 
> <yahoo.messenger@m...> wrote:
> >
> > Thanks, Brendan. Yes, I thought of a hardware reset, but 
modifying 
> > the board is no longer an option at this stage. However, I would 
> like 
> > to -by software- do my best effort to handle this, although I 
know 
> I 
> > can't really cover all bases.
> > 
> > About the watchdog, I am concerned about such a short timer. 
Since 
> > there is no way I can turn the watchdog off by software, couldn't 
> my 
> > reset procedure be continually called by the watchdog, with not 
> > enough time to reset it properly? The LPC2138 user manual doesn't 
> say 
> > if the watchdog is stopped after triggered (or at least I 
couldn't 
> > find a word about it). In fact, once the watchdog is set up, what 
> > attributes am I allowed to change from it afterwards?
> >
>