control memory block in FPGA from Host

[lightmiddle]

Hi

I am using Labview 7.1 for windows and FPGA 1.1 version. And NI PXI 7833 R card.

Now I wanna control to write or not write to the memory block in FPGA .

 I wrote a FPGA vi and run in FPGA . I could put the "write in " to be true to write the "data in " to memory block.

and verified with the output from memory block.

  Then I wrote a host vi. This time when I pushed the "write in " button to be true. the data from the memory all were zeros. which means the data might not be written to the memory block.

 Here are the two VIs. any help would be appreciated.

Message Edited by lightmiddle on 03-24-2006 05:31 PM

[Khalid]

Where are you running the Host VI?  Targeted on the cRIO-RT? 

If you're running this from the desktop, then you have to provide the VISA Resource as the input to the FPGA Reference VI. 

Hope this helps.

-Khalid

[lightmiddle]

running at Labview for Windows (xp Operation System)

[Dustin_W]

Remember that the FPGA and Host application run asynchronously - they are two separate VIs running in two separate places.  As soon as you open the FPGA reference, the FPGA will begin running (assuming you have the default 'open and run' selected on the open VI reference).  Most likely what is happening is that your memory writes are all happening long before the your host VI get's to a point where you send any information down to the FPGA.  Depending on what you have the write? boolean default set to, it is either going to not write, or write whatever your default data value is (I'm guessing a 0) in this case.

I suggest using some type of handshaking to ensure the memory write does not happen before you you expect it to.

-Dustin

[lightmiddle]

Yes, Dustin:

 You are right and your guess is right as well. I modified my VIs and it is working right now. Thanks a lot.