[U-Boot-Users] Software emulation exception on entry into RAM

[Thomas Laman <tlaman@rochester.rr.com>]

Wolfgang Denk wrote:

>In message <410A157E.5060307@rochester.rr.com> you wrote:
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>>In my board specific code, after initialization of the SDRAM, I have 
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>code that writes the address as data to that address - write 0x0 to 0x0, 
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>>0x4 to 0x4, etc. After the Software Emulation Exception, I go into the 
>>SDRAM and the code is copied correctly in the used areas, and my pattern 
>>is in the other areas.
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>And which data are you RADING from SDRAM? 
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The data that was copied prior to the branch to SDRAM.

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>>Because of this, I don't think my SDRAM settings are being changed.
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>You wrote you are using a BDI2000 - you can use  it  to  single  step
>into  the  code  in  SDRAM.  What  does  this give? And if you get an
>exception - where does it happen? What was the incorrect data?
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I get an exception on the first access of SDRAM (the address branched to 
from flash). The data is correct. I will have access to a logic analyzer 
this weekend and will check out the SDRAM burst read access.

>You got the tools - use it to analyze your problem [or just save  the
>time   and  re-check  your  SDRAM  initialization  against  the  chip
>manufacturer's manual; at least this is what I would do if I  was  in
>your position.]
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I have checked the SDRAM initialization and it appears to be correct. 
With the logic analyzer, I will check out the burst read cycle.

>Best regards,
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>Wolfgang Denk
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