Lpc2000

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?
>