Lpc2000

I have been wondering about that myself.

If you look very closely at the past threads, in this forum, others 
have been wondering about this also.

I have scoured all the LPC2xxx errata; and I have found no mention of 
this either.

It could very well be that certain revisions of the LPC22xx silicon 
may have this feature, whereas the later revisions may not, or that 
there is an errata in the UM.

In either case, I am very happy with the current state of affairs with 
my customer's projects using the LPC22xx...In that they all work 
pretty much flawlessly, (where the WDT is concerned).

To date, the best information I have gotten, on some of the 'features 
of the LPC22xx' has come from this forum.

These caveats include:
1.  WDT issues
2.  PLL setup and the VPB divider errata
3.  Changing between default level-triggered vs. edge triggered 
interrupts, (don't do this!)
4.  Changing between default low-level vs. high-level interrupt 
source, (again, don't do this!)
5.  Of course, the oft-repeated spurious interrupt issue. There was 
enough within the manuals, and this forum to scare me into doing 
something over-engineered (in my opinion)...but is guaranteed to work.

What I have done, in general, is read all the threads on these various 
topics, and try to ascertain how much trouble people out there are 
having with the various LPC2xxx issues.

Ken Wada

--- In lpc2000@yahoogroups.com, "Karl Olsen" <kro@p...> wrote:
>
> ---- Original Message ----
> From: "Ken Wada" <kwada@a...>
> To: <lpc2000@yahoogroups.com>
> Sent: Saturday, December 10, 2005 12:17 AM
> Subject: [lpc2000] Re: Problem with watchdog
> 
> > ok...
> > I can surely tell you this...
> > I had the Watchdog working perfectly, until I started adding 
interrupt
> > support, (mainly device drivers for the UART). After days of 
pulling
> > my hair out, and interpreting the UM for the LPC2214 as a lawyer 
would
> > do; it occured to me that the UM says 'feed 0x55 then 0xAA' It 
made
> > absolutely no mentioned about what may happen if the process got
> > preempted by an interrupt...
> > 
> > Then alas; when I installed my 1st interrupt service routine; all
> > worked fine, for a few hours, and sometimes for a couple of days..
.
> > 
> > Then my clients started complaining about 'these spurious reset
> > events'. They demanded that I fix the problem right away.
> > 
> > SO...
> > I came to this forum: AND I saw this:
> > message #5470 ---> Please also read all the threads that spawned 
from
> > this message.
> 
> OK, it certainly looks like an interrupt between the feed writes 
will reset
> the CPU.  All the manuals, including the new LPC2103 manual, have 
the same
> wording about WDFEED.  philips_apps, is this a bug in the manuals or 
in the
> chips?
> 
> Karl Olsen
>