Re: Problems with the NI PCI-6110

I figured my code was reading quicker than the card can dump to dma’d 
space.  So I assume the solution would be to slow down my reading to 
under the speed of the DMA transfer from the card.  From my reading its 
seems the mMITE handles the DMA operations, but I know the available 
data on the MITE/mMITE is small.  Does anyone have numbers as to how 
fast the mMITE can write back to DMA’d space?  Or alternatively is there 
a way to determine the speed/timing at which the card is trying to write 
back at?
If I can determine the speed/timing of the writeback to DMA, what is the 
best comedi-friendly method to slow down my read()’s as to not overrun 
the dma buffer?  Comedi_udelay()? 

Doug

Frank Mori Hess wrote:

>Your program still has to read() the data from comedi's kernel buffer 
>faster (on average) than the card is dma'ing it into the buffer.
>
>- -- 
>Frank
>  
>

-- 
==============================
Doug Farley

Safety Critical Avionics Systems Branch 
NASA Langley Research Center

< D.L.FARLEY_at_LaRC.NASA.GOV > 
< Phone +1 757 864-8141 >

Received on 2005-01-03Z20:13:48