XUP JTAG-USB serial number issue

[acb]

I have recently purchased two XUP JTAG programming cables for use in debugging a transmitter and receiver design using Vivado 2016.4.  The issue I face is that when both of them are plugged into the same PC, only one shows up.  I believe I found a related post which seemed to indicate that the XUP does not set the serial number. I believe that is what I am seeing as well; mine just reports a long string of zeros.

https://forum.digilentinc.com/topic/4437-multi-xup-jtag-usb-programming/?page=0#comment-17535

My question is now that almost a year has passed since this linked post was updated, has there been a new release of software, firmware or whatever that fixes this issue.  If I use a newer version of the Xilinx Lab tools does this issue resolve (I am using Vivado 2016.4).  Some people have mentioned USB port-based identification. Since I am only using two I could probably make do with that method of connection.  Could someone at least explain how I would go about doing that?

 

Thanks,

Craig

 

[jpeyron]

Hi @acb,

There has not been a change to the firmware that would set serial numbers for the XUP JTAG USB.  USB port-based identification I believe refers to distinguishing between the two XUP JTAG USB through the com ports. I do not have 2 XUP JTAG USB's to help with getting them going. Please  attach a screen shot of what you see with both XUP JTAG USB's connected in vivado.

thank you,

Jon

 

 

 

[acb]

Thanks @jpeyron,

Correction - it seems that I can not plug both XUP devices into the PC at the same time and scan for new hardware; the system will just keep searching and neither of them will come up.  

When I plug in the XUP into the Rx board and scan for new hardware I get this screen:

After I finish connecting I get the following tcl output:

And the Device Properties window looks like this:

So it appears that the system can identify my FPGA (I think that is the IDCODE_HEX) but the long string of zeros in the DID is where the serial number of the JTAG is supposed to go.  

When I plug in the other XUP into the Tx board I get this tcl output:

and this device properties window:

Different device ID (and different FPGA part number); but still the same long string of zeros for the JTAG serial number (note this is a different physical JTAG cable).

As I stated, if I plug both cables into the PC at the same time and try to scan for hardware, the system hangs.  If I plug one in at a time either one comes up.  If I am already connected to one device and plug in the other JTAG cable, I seem to stay connected but the new hardware never shows up, it never tries to scan for changes or anything.  This is very different from the behavior I would see if for example I plugged in two platform USB cabels or two KC705 boards.  Both of them show up.

Thanks,

Craig

[jpeyron]

Hi @acb,

I reached out to one of our design engineers about this forum and they responded that "we didn’t write the manufacturing test for the XUP USB cable but it sounds like no serial number string is set at the time of manufacturing. If that’s the case, then I’m not sure that there is any way to set it. I’m also unaware of a way to tell Vivado or iMPACT which device to open. Since this doesn’t run Digilent firmware I have no idea how to fix it."  We manufacture the XUP USB cable for Xilinx. I would suggest to reach out to xilinx support.

thank you,

Jon

[acb]

Hi Jon,

Thank you for your continuing help and support on this issue.  

Given what your design engineer said, it sounds like there is a consistent flaw in Digilent's manufacture of this product.  Either there is a process step that has been consistently left out of the manufacturing flow or there is an issue with the Xilinx firmware.  As the manufacturer of the product, I'm sure Digilent will have more clout with Xilinx in getting this problem resolved than a single end user.  

I would suggest Digilent come up with a resolution for this design flaw or at a minimum clearly disclose on the product page that there is no serial number set and that only one XUP USB cable can be attached to the PC at a time.  

Respectfully,

Craig