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RE: IDE unable to read partition table



Hi Jarkko,

I have now found the error why my IDE interface was not working.
The intrq1...intrq3 on my hardware which were not connected have flooded
the etrax with interrupts.

Thank you for your support
Christian

-----Original Message-----
From: owner-dev-etrax@xxxxxxx.se">mailto:owner-dev-etrax@xxxxxxx.se] On Behalf Of
Jarkko Tuomi
Sent: Sonntag, 13. Juli 2003 23:05
To: codedrone@xxxxxxx.de
Cc: dev-etrax@xxxxxxx.com
Subject: RE: IDE unable to read partition table

Christian wrote:
> I omitted the isolation buffers for the time being to test and attached
> the hd direct to the pins, because I think they do nothing. Could this
> be the problem?

That's it. The output current of Etrax io pins is just a fraction of the
current the external buffers can supply. Also the output voltage and thus
the achieved noise margin are lower. It seems to work also without
buffers, provided that you keep the cable short (just a few cm) and relax
the timings at os/linux/arch/cris/drivers/ide.c.

I once tried with the default timings and it didn't work with a 10 cm
cable. The values you should take a look at are PIO4 (drive detection) and
DMA2 (data transfer).


Hopefully this helps,


Jarkko