[U-Boot-Users] SDRAM init problem? Was Re: uboot 1.1.2 problem

[Clemens Koller]

Hi, Sam!

As Wolfgang said, check the voltages, caps, terminations...

You might also try to actively lower/rise the voltages of
your board/ram/... a bit. If your problem changes, I would
bet it's a hardware problem.

Greets,

Clemens

Sam Song wrote:
> -- Wolfgang Denk <wd at denx.de> wrote:
> 
>>>Thanks. Actually, it involves the grey area which
>>>a probelm was supposed to produce by hardware or 
>>>software. The golden role is to check SW first.
>>
>>You must be one of these hardware guys who always
>>blame the software.
> 
> 
> Firmware guys is better to me. I amn't willing to 
> be an native HW fellow although I come from HW 
> field. To blame right is my hope. SW is only one
> side:-)
> 
> [snip]
> 
>>We've seen lots of "funny" problems with the many
>>boards we lay hands on. Three more things to check:
>>
>>* Check the voltages on your system: tolerances ok?
>>spikes  or  other noise on the lines? especially 
>>close to the CPU?
>>* Check the clocks. Check the clocks again.
>>* check for unconnected pins, missing pull-ups or
>>-downs, or incorrect resistor values
> 
> 
> Ummm, this is really what I want. It seems I should
> look back more to take case HW side:-)
> 
> Thanks so much,
> 
> Sam
> 

-- 
Clemens Koller
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