fpga data clock enable (5171r)

[bcl511]

Hello!

I am working with a PXIe 5171r reconfigurable scope.  It is installed and the sample program runs fine but I am running into trouble when I try to make my own program.  Along with the usual 40MHz clock the 5171r has a 250MHz clock which drives the ADCs (125MHz and 375MHz clocks are also provided).  When I run my program it behaves as though the data clock is not running.  I've attached the code that I am running, which sends a value down to the FPGA via DMA FIFO, pipes it into the 125MHz clock domain, then immediately sends it back to the 40MHz domain and back up to the PC (again, via DMA FIFO).  This program runs as expected when everything is on the 40MHz domain but when I run the secondary loop on the 125MHz clock (data clock).  I get nothing back.  The 5171r also has 8 user IO and I set pairs of them to toggle based off of the 40MHz, 125MHz, and 250MHz clocks as a sanity check and I only see the 40MHz clock active.

I spent some time looking through the instrument design libraries to see if there was some step that needed to be taken to enable the data clock, or set the clock source (it can be driven from either internal or external source) but I found none.  I know the user base for these things is not large but maybe someone has an idea of where to look to get this clock going?  At 1 hour per compile cycle my trial and error has been pretty slow!

thanks a lot!

Ben

[bcl511 · Accepted solution]

Hi Again,

I kept digging on this and finally found the place in the IDLs where the clock is set up.  It looks like I had misunderstood the degree to which the IDLs are necessary for operating this device so in a sense the premise of my original post was actually wrong.  If I might make a humble suggestion - it would be nice to have some kind of documentation that gives and overview of the libraries and how they map into the device's physical capabilities.  Or maybe that too already exists and I just haven't found it yet?  I can't complain too much since the libraries are completely open, but figuring out what they do by looking through each function is a pretty painful process!

[prof.maio@gmail.com]

HI,

you could specify where you enable the date clock?

Thanks

Giovanni