Lpc2000

derbaier wrote:

>--- In lpc2000@yahoogroups.com, Michael Johnson <mpj@r...> wrote:
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>>Debug from reset doesn't work on any LPC2xxx boards we have. If it does 
>>work on the chip (which I doubt) then one of the many LPC2xxx board 
>>vendors could gain a technical advantage by producing a board that is 
>>correctly wired up. Philips don't seem to want to talk about this
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>area - 
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>>we asked a long time ago and received a similar answer to yours.
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>>Regards
>>Michael
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>ARM Application Note 31 talks about debugging directly from RESET, so
>it *can* be done. I am just getting started using Phillip's products,
>but I used to work for a chip manufacturer that used embedded ARM
>cores, and we also had problems with our earlier reference design
>circuit boards debugging from RESET. The ARM7TDMI can be debugged
>directly from reset, but it does take a correct circuit board and JTAG
>pod design to do it since JTAG has to come out of RESET before ARM
>comes out of reset accord to AN31. After we reworked our reference
>design circuit board hardware, we were able to debug software out of
>reset.  That was a really critical necessity at the time, since we had
>some write once registers for system configuration that needed to be
>written to very early in the normal boot sequence. If they were
>written before the debugger got control, it was too late to debug any
>difficulties related to that part of the system configuration.
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I know that other ARM devices/boards can be debugged from reset, we have 
quite a few of them. Perhaps the LPC2xxxx boards we have (made by 
theARMPatch, IAR, Olimex, Keil and Nohau) have all got the reset wiring 
wrong - but I doubt it.

Regards
Michael

>--Dave
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