From: Arto Vuori <avuori@ssh.com>
To: acurtis@onz.com
Cc: linuxppc-embedded@lists.linuxppc.org
Subject: Re: 8260 IDMA experience?
Date: Mon, 03 Jun 2002 16:56:37 +0300 [thread overview]
Message-ID: <3CFB7595.AF86DFF0@ssh.com> (raw)
In-Reply-To: NCBBIINEHIPFGJPLBEIFOEAFDIAA.acurtis@onz.com
Allen Curtis wrote:
> So it works but it may not be as fast as a memcpy(). Sounds like more
> testing is required to determine the overall benefit of freeing the
> processor.
Right. We are using IDMA only for accessing slow devices, so that CPU
don't need to wait for the data and can do some usefull work
simultaneously.
>
> > I did also notice that when i am doing memory-to-peripheral (or
> > vice-versa) transfers, IDMA corrupts simultaneous Ethernet traffic
> > unless IDMA is set to low-priority mode. Same might apply for
> > memory-to-memory transfers.
>
> What 8260 chip revision are you using? I have found lots of problems when
> rev A processors but rev C has been much better.
I have done most of my testing with revision A chips. I've had many
problems with those chips and it took some time with logic analyzer to
debug those IDMA transfers before i got them working.
Arto
--
Arto Vuori
email: avuori@ssh.com
mobile: +358 40 754 5223
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
prev parent reply other threads:[~2002-06-03 13:56 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-06-01 3:15 8260 IDMA experience? Allen Curtis
2002-06-03 12:33 ` Arto Vuori
2002-06-03 13:20 ` Allen Curtis
2002-06-03 13:56 ` Arto Vuori [this message]
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