UDMA for Compact Flash over PC Card?

Steven Newbury s_j_newbury at yahoo.co.uk
Fri Apr 6 12:52:18 EDT 2007


--- Piotras <piotras at gmail.com> wrote:

> Am I correct to assume that the PXA DMA engine is using
> DMA signaling on the PCMCIA bus? Do you use WIN_READDMA*/
> WIN_WRITEDMA* commands to access the CF card?
> 
> Could you provide the details of your CF card?
> 
The former, the PXA DMA engine is very flexible.  The card is initialised
normally and then subsequent IO requests are sent and recieved in mutli-byte
bursts over the bus.  The CF card just operates normally.  Similar performance
can be achieved by using multi-sector IDE transers if your CF card supports it
although with more CPU load.

I've attached a patch that is also integrated with Thomas' MMIO patch although
as I said I couldn't get it going unfortunately.

By the way I didn't originally write the PXA PIODMA patch I just cleaned it up
and fixed a few bugs, and I'm not sure who did.  I got it from Richard Purdie's
archive in the tosort directory, it was part of a larger somewhat broken patch
tof random local changes that somebody had sent to Richard.  He may remember
who it was...

Steve


		
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