Subject: Re: pciide, DMA, and the alpha...
To: Bill Studenmund <email@example.com>
From: Manuel Bouyer <firstname.lastname@example.org>
Date: 08/12/1999 19:08:09
On Thu, Aug 12, 1999 at 10:04:06AM -0700, Bill Studenmund wrote:
> On Thu, 12 Aug 1999, Manuel Bouyer wrote:
> > Note that the CMD0646 is a cheap but weird chip. Especially it can't use
> > both channels at the same time, access has to be serailised (that's because
> > some internal registers are shared between the 2 channels).
> I was under the impression that only the 640 had that problem. Shouldn't
> the later chips be ok?
Never tried, but from the docs I fear it's not. I even have a web page
explaining how to serialise access to the channels when using DMA.
Maybe it's ok for PIO, but do you want to use parralel PIO or serialised DMA
Manuel Bouyer, LIP6, Universite Paris VI. Manuel.Bouyer@lip6.fr