fpga

[Wes_Ramm1]

I am playing with P2P streaming, and have a DMA FIFO configured to take my data from the FPGA to the Host PC.  

Under the FPGA Target (7962), the DMA FIFO is configured for 32767 points.

When I try to "read" more than 10,000 points on my FIFO Read on the Host PC, I get the following Error:

Error -61073 

Invoke Method: FIFO.Read in niScope EX P2P Multi Record Analog Trigger HOST.vi

The DMA fifo is configured larger than this in the Project Explorer.  The Properties dialog of the DMA FIFO allows me to set this size (but nothing larger), but when I try to read anything larger than 10,000 for "record length" I get this error.

Any ideas?

Thanks,

Wes

[WillD · Accepted solution]

The DMA FIFO is actually implemented in 2 parts, you define the FPGA size in the project explorer(actual FPGA fabric), the Host side is defined programatically (Host RAM).

There is a configure method you can run on the Host, the default for the Host side is 10,000 elements.  I would set the FPGA side much smaller, 1000 or so elements, save a lot of FPGA fabric.  Configure the Host side to 64,000 or something.

Edit:

Here is a help link to the Configure method:

http://zone.ni.com/reference/en-XX/help/371599E-01/lvfpgahost/fpga_method_fifo_config/

and a link to the DMA FIFO help:

http://zone.ni.com/reference/en-XX/help/371599E-01/lvfpgaconcepts/pfi_data_transfer/#DMA_FIFOs

Message Edited by WillD on 05-11-2010 08:25 AM

[Wes_Ramm1]

An objective, helpful, correct answer.  Nicely done!

Wes

[WillD]

Glad you hear you got it working.