Software triggered DMA on 823e?
bobtek at fishcamp.com
Sat Jul 13 04:50:07 EST 2002
The chip definitely requires that the DREQ signal be used to start a DMA
transfer. That is even if you are doing memory-to-memory transfers.
See section 126.96.36.199 in the Reference manual.
105 W. Clark Ave
Orcutt, CA 93455
From: owner-linuxppc-embedded at lists.linuxppc.org
[mailto:owner-linuxppc-embedded at lists.linuxppc.org] On Behalf Of Hihn
Sent: Friday, July 12, 2002 10:06 AM
To: linuxppc-embedded at lists.linuxppc.org
Subject: Software triggered DMA on 823e?
We're doing a design and due to the way some of our devices work, we
do a DMA transfer on an interrupt from a peripheral. My team is
if we can write a interrupt handler that will initiate the DMA xfer
having to use external pins, or if we have to route an output pin to
and trigger it that way.
Our peripheral is a memory mapped device, but it's only a buffer. We
catch its interrupt and DMA the buffer out to a place for our
We've been all over the manual and can't find the answer.
Any help is appreciated.
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