7831 FIFO and Memory

[pegel2]

Hi,

I have to use a NI7831 FPGA Board for some digital/analog input and output tasks.

For data transfer it is not quite clear when I have to prefere the FIFO (DMA) Function or using Read and Write Memory (configurated by the Memory Extension Utioity).

Is there a quick manual to the the differences/advantages of the two different methods ?

Peter  

[Jochen]

The answer is quite simple. DMA (Direct Memory access) is much faster than programmed I/O so whenever applicable you should use DMA. Currently DMA is only supported for transfers from the RIO board to the host PC. R&D is currently working on a solution to support DMA transfers from the host PC to the RIO board, too but we don't know when this feature will be released, yet.

Here are some links with further information:
Using DMA FIFO to Develop High-Speed Data Acquistion Applications for Reconfigurable I/O Devices
DMA Improves LabVIEW FPGA 8.0 Throughput by 20X
FPGA Design, Development and Programming Tutorial

Jochen Klier
National Instruments Germany