Lpc2000

Hi All !!

I am a student at University of applied science Augsburg and currently
working on my Final Year Project.
It is a Webserverboard based on a LPC2214 with 4MB external SRAM to be
able to run uCLinux.
I build the board and tested the external memory using a little test
routine.
I wrote  a value to a pointer in the external SRAM and read it back.
Everything looks ok so far, but if i load ucLinux in the SRAM, i get an
interrupt for an undefinded intstruction.
If i use OpenOCD and have a look at the memory, i saw, that the content
is not right. The upper half-word is on a different address the the
lower half-word. It looks like that the upper half-words have on offset.

If i write to memory using a pointer in a C-routine, everthing looks ok
!! Even if i check the content of the memory with OpenOCD. !!

Has anybody an idea, where i can have a look for the error ??

Thanks,
Timo

At 09:44 AM 4/25/2006 +0100, Timo Bruderek wrote:
>If i write to memory using a pointer in a C-routine, everthing looks ok
>!! Even if i check the content of the memory with OpenOCD. !!
>
>Has anybody an idea, where i can have a look for the error ??

Some debugging suggestions.  It's possible but unlikely that  uCLinux  is 
copying in a strange fashion.  The first thing to do is probably to verify 
your memory interface is performing properly.  The simple test you've 
performed is a start but it's not sufficient.  You need a full memory test 
to check for various possible fault like stuck or shorted address lines.  I 
don't have one handy but I think Embedded Systems had a nice one a while 
back and I'm sure someone here could point you to a good starting point.

Robert


" 'Freedom' has no meaning of itself.  There are always restrictions,   be 
they legal, genetic, or physical.  If you don't believe me, try to chew a 
radio signal. "  -- Kelvin Throop, III
http://www.aeolusdevelopment.com/

Hi Timo,

Take a look at:
http://www.ulrichradig.de/site/arm_projekts/webserver/index.htm
Look for eagle schematics.
Or put a message on this forum:
http://www.ulrichradig.de/site/forum/index.php
Regards,
 Marcio
--- In lpc2000@yahoogroups.com, Timo Bruderek <timo.bruderek@...> wrote:

>
> Hi All !!
> 
> I am a student at University of applied science Augsburg and currently
> working on my Final Year Project.
> It is a Webserverboard based on a LPC2214 with 4MB external SRAM to be
> able to run uCLinux.
> I build the board and tested the external memory using a little test
> routine.
> I wrote  a value to a pointer in the external SRAM and read it back.
> Everything looks ok so far, but if i load ucLinux in the SRAM, i get an
> interrupt for an undefinded intstruction.
> If i use OpenOCD and have a look at the memory, i saw, that the content
> is not right. The upper half-word is on a different address the the
> lower half-word. It looks like that the upper half-words have on offset.
> 
> If i write to memory using a pointer in a C-routine, everthing looks ok
> !! Even if i check the content of the memory with OpenOCD. !!
> 
> Has anybody an idea, where i can have a look for the error ??
> 
> Thanks,
> Timo
>

Hi Robert !

Thanks for your idea !
I have desoldered one of the memory chips and limited the SRAM to 2MB now.
At the moment, i have no error and uCLinux is booting up to a certain
point without any memory problem.

I will try to replace the other chip with a new one. Maybe it it damaged
by ESD or something else.

Before i desoldered, i meassured at the address lines and all seams ok.
No error so far ! It is a little bit strange.

Thanks,
Timo

Robert Adsett schrieb:

>At 09:44 AM 4/25/2006 +0100, Timo Bruderek wrote:
>  
>
>>If i write to memory using a pointer in a C-routine, everthing looks ok
>>!! Even if i check the content of the memory with OpenOCD. !!
>>
>>Has anybody an idea, where i can have a look for the error ??
>>    
>>
>
>Some debugging suggestions.  It's possible but unlikely that  uCLinux  is 
>copying in a strange fashion.  The first thing to do is probably to verify 
>your memory interface is performing properly.  The simple test you've 
>performed is a start but it's not sufficient.  You need a full memory test 
>to check for various possible fault like stuck or shorted address lines.  I 
>don't have one handy but I think Embedded Systems had a nice one a while 
>back and I'm sure someone here could point you to a good starting point.
>
>Robert
>
>
>" 'Freedom' has no meaning of itself.  There are always restrictions,   be 
>they legal, genetic, or physical.  If you don't believe me, try to chew a 
>radio signal. "  -- Kelvin Throop, III
>http://www.aeolusdevelopment.com/
>
>
>
> 
>Yahoo! Groups Links
>
>
>
> 
>
>
>
>
>  
>


[Non-text portions of this message have been removed]

Hi !

Thanks for the tip, but i did it already. My schematics are a little bit
different in regard to the memory chipselect generation, but i think
that is not the problem.

thanks for help
timo

atmelbr schrieb:

>Hi Timo,
>
>Take a look at:
>http://www.ulrichradig.de/site/arm_projekts/webserver/index.htm
>Look for eagle schematics.
>Or put a message on this forum:
>http://www.ulrichradig.de/site/forum/index.php
>Regards,
> Marcio
>--- In lpc2000@yahoogroups.com, Timo Bruderek <timo.bruderek@...> wrote:
>  
>
>>Hi All !!
>>
>>I am a student at University of applied science Augsburg and currently
>>working on my Final Year Project.
>>It is a Webserverboard based on a LPC2214 with 4MB external SRAM to be
>>able to run uCLinux.
>>I build the board and tested the external memory using a little test
>>routine.
>>I wrote  a value to a pointer in the external SRAM and read it back.
>>Everything looks ok so far, but if i load ucLinux in the SRAM, i get an
>>interrupt for an undefinded intstruction.
>>If i use OpenOCD and have a look at the memory, i saw, that the content
>>is not right. The upper half-word is on a different address the the
>>lower half-word. It looks like that the upper half-words have on offset.
>>
>>If i write to memory using a pointer in a C-routine, everthing looks ok
>>!! Even if i check the content of the memory with OpenOCD. !!
>>
>>Has anybody an idea, where i can have a look for the error ??
>>
>>Thanks,
>>Timo
>>
>>    
>>
>
>
>
>
>
>
>
> 
>Yahoo! Groups Links
>
>
>
> 
>
>
>
>
>  
>


[Non-text portions of this message have been removed]