AT91RM9200 problems to run from SDRam

Hi,

We build own at91 board with an AT45DB642 and 64MB of SDRam.
Above I'll describe some details.

At45DB642 is attached to at91rm9200 on CS0 and SDRam is using a 32bits
of data path.
We already tested both, and they are working without any kind of
problem.  We wrote data on At45DB642 and read it without errors, the
same occured with SDRAM.

What occurs is that when we run a program from internal ram, everything
goes fine.
But when we try to run some program from SDRam we get an 0xff on debug
serial port.  And the program doesn't run.
We tested, our software, loader.bin and romboot.bin.

Does anybody see something like it?

Tkz,
Reiner

In comp.arch.embedded,
Reiner <reineruhry@gmail.com> wrote:
> Hi,
>
> We build own at91 board with an AT45DB642 and 64MB of SDRam.
> Above I'll describe some details.
>
> At45DB642 is attached to at91rm9200 on CS0 and SDRam is using a 32bits
> of data path.
> We already tested both, and they are working without any kind of
> problem.  We wrote data on At45DB642 and read it without errors, the
> same occured with SDRAM.
>
> What occurs is that when we run a program from internal ram, everything
> goes fine.
> But when we try to run some program from SDRam we get an 0xff on debug
> serial port.  And the program doesn't run.
> We tested, our software, loader.bin and romboot.bin.
>
> Does anybody see something like it?
>
Are you sure your code is OK and does the link address correspond with
the address range of the SDRAM?

How sure are you that your SDRAM works OK and how did you test it? If you
for instance tried write and read in fast succession and that went OK, you
may still have a problem with your refresh.

-- 
Stef    (remove caps, dashes and .invalid from e-mail address to reply by mail)