Re: continuos ai pxi6070 acquisition and PCI burst mode.

On Wednesday 02 February 2005 11:49 am, David wrote:
> Hi all
>
>
> We are having problems to acquire from 5 pxi 6070. Each card has been
> configured with 12 channels at 100KS/s. The acquistions stops after few
> time. We have big comedi buffers.
>
>
> Using a logic analyzer we have seing pci bus cycles and during
> acquisition time, no burst transfers are used to send data from
> acquisition cards to comedi buffers. PCI has its best performance in
> burst transfers and we would like to know if comedi use one addres phase
> and one data phase for each sample due to any reason or if it is posible
> to configure comedi to use burst transfers.
>
>
> We have tried to change master latency timer in pxi 6070 cards but no
> burst transfers are obtained.

The CHCR_BURSTEN bit in the channel control register (MITE_CHCR()) enables 
burst transfers.  Try setting it in mite_prep_dma().

-- 
Frank