MPC85xx DMA support for Kernel 2.6?

Dan Malek dan at embeddededge.com
Sat Jul 2 07:49:52 EST 2005


On Jul 1, 2005, at 10:15 AM, Mark Chambers wrote:

> Is the SRAM being cached?  I don't think the CPU will generate bursts
> unless it's cached, right?

I don't really remember :-)  I know the 8xx will not burst if the line 
isn't
cached, and I know the 7xxx will.  I thought the 82xx and 85xx would
also burst if you had sufficient sequential operations queued.  On
83/85xx you have to further qualify the discussion based upon the DDR2
or the local bus interface :-)  The CPM and DMA will burst on all
buses for 8xx/82xx/83xx/85xx if the memory controller is configured
to do so.

I always end up writing code to test it, then those brain cells get
replaced by more meaningful experiences before I have to use
them again :-)

Thanks.


	-- Dan




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