Lpc2000

Check your power up reset signal length, it should be at least 10ms
(AFTER V18 is stable, check this).  If it is shorter than this the
processor may enter an "unknown state".

Richard

--- In lpc2000@yahoogroups.com, "moostieuk" <moostieuk@y...> wrote:
> 
> It's definately "latched up" in one way, cycling the reset line
> doesn't bring the chip out of the mode (which you would expect it to
> do).  Only thing to do is to completely power the board down so that
> the rails have all collapsed.
> 
> The board starts up perfectly nearly every time, it's once in a while
> it doesn't turn on when you apply power or you start switching the
> power supply on and off rapidly, then you are able to make it happen
> more often.
> 
> It's the lack of the processor not getting out of this state when
> reset is toggled that indicates it's a problem with the processor.
> 
> And with regards to attaching the debugger, I just decided to give
> that a go to see if I could actually talk to it, nobody on the list
> here has ever mentioned trying this - when I attach the debugger and
> break it's jumped to the undefined instruction handler (which branches
> to itself).  I don't understand how it thinks it's able to get here
> because the software/board runs perfectly 99% of the time.
> 
> 
> 
> --- In lpc2000@yahoogroups.com, "Richard" <richas@y...> wrote:
> > 
> > If you find yourself in an exception handler, probably looping
> > indefinetly because it is not really a "handler", then you are not
> > latched up, yoou are executing code.
> > 
> > Richard
> > 
> > --- In lpc2000@yahoogroups.com, "moostieuk" <moostieuk@y...> wrote:
> > > 
> > > We appear to have this problem on the LPC2114.  Our prototype board
> > > appears to latch into a state sometimes on powerup.  If you take the
> > > reset line down and back up when in this state the processor still
> > > doesn't come up.
> > > 
> > > Interestingly, if you attach the debugger to the processor it's
> > > sitting in the "undefined instruction" handler, if you tell it
to jump
> > > to the reset handler it does so and starts to execute but then finds
> > > it's way back into the undefined instruction handler....
> > > 
> > > This problem is most noticable when flicking the power on and off
> > rapidly.
> > > 
> > > Philips, I think we have a problem......
> > > 
> > > --- In lpc2000@yahoogroups.com, "g2100g" <g2100g@e...> wrote:
> > > > As described in the Errata Sheet, available on Philips web site:
> "The 
> > > > last letter in the third line (field `R') will identify the
device 
> > > > revision." 
> > > > 
> > > > --- In lpc2000@yahoogroups.com, "jamesradix1969" 
> > > > <jamesradix1969@y...> wrote:
> > > > >
> > > > > How can you tell which version of the chip you have?  Is it
> part of 
> > > > > the printed markings on the chip?  Do other family members
(2129) 
> > > > > have this problem too?
> > > > > Thanks,
> > > > > James