Problem with SDRAM SAMSUNG K4S511632D-UC75

Hi!

With our current SDRAM initialization (in our boot code), sometimes the
SDRAM does not work correctly after power-up reset. Every second quad-word
can't be accessed (it seems that it can't be written).

When the SDRAM is in this erroneous state after power-up, repetitive
resets (not power-up) won't resolve the problem. Only a power-off/on cycle
will resolve the problem.

So I think, something is missing or wrong in the initialization sequence.

We are using a Technologic Systems TS-7200 board with an EP9302 CPU.
The initialization code we took is from the Open TS-72XX system boot
code.

The data*** of the SDRAM does not cover the initialization sequence.


Any ideas?


Thank you in advance!
Gerhard



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