Lpc2000

At 07:50 AM 12/19/05 +0100, Rob Jansen wrote:
>Robert Adsett wrote:
> > And this is where something else is needed. I haven't seen any way to
> > deal
> >
> >with timing issues with JTAG, for that the most effective way seems to be
> >pin toggling.  Then there are those problems that you cannot stop the
> >microprocessor since to do so will necessarily result in invalid results in
> >the best case and blown hardware or worse in other cases.  There are a
> >number of problems that the only effective way I've found to deal with is
> >to provide a data log that is later downloaded to a PC for analysis at a
> >safe or convenient point.
> >
> >
>Data log ... especially usefull todiscover these nice interrupt related
>bugs ...
>But for timingrelated  stuff there are the ETM/ETB that can be part of
>the ARM core.
>The lpc3000  contains an ETM, worked great for my timing issues on a
>926EJ-S.

I've always used a scope for timing.  I can't imagine even a full ICE being 
particularly helpful there. Much less ETM.  Maybe we are talking about 
different things?

> >I am a little worried that the presence of JTAG has meant that there is no
> >real ICE for the ARMs so that the most powerful tool in the development
> >arsenal is going to be missing when a really intractable problem
> >appears.  I expect ETM would cover most of the remaining territory but a
> >lot of the new parts don't have that support and of course it takes away
> >even more pins.
>For embedded processors real In Circuit Emulators are almost not
>feasible, you needto rely on stuff

I've worked on several embedded processors with ICE support.  Indeed my 
experience is that they are far more common in the embedded than in the 
non-embedded world.  Most non-embedded developers get by with a hosted 
debugger as their most powerful tool.

>like ETM of ETB.
>Problem is support by JTAG debugger pods. Either not available or
>expensive ...
>I have also not seen ARM7 with ETM yet (have not looked for it though)

The LPC2104/5/6 have ETM.  Philips dropped support for it on most (all?) 
later variants.

Robert

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