How do I connect XTAG-3 to custom hardware?

[fas]

Hi, new to XMOS devices. We have a custom hardware design using an XU-216-128. I've checked that all voltages, clocks and reset are correct. JTAG is connected to a 20-pin header into which an XTAG-3 is connected. The XTAG-3 shows up in Windows Device Manager. However when I execute xrun -l I get "No Available Devices Found".

Is there something I need to do to tell the system about the hardware? I've combed through all the documentation and the forum and can't find anything. I've tried different USB ports. I've tried power cycling and manually asserting the reset.

Thanks

[mon2]

Hi fas. Can you post the relevant parts (power supply, clock, XMOS CPU, remove your secret sauce on the i/o pins if you wish) of your schematic for a review ?

In the meantime, please review sections G, H & I of the XU-216-128 datasheet:

https://www.xmos.com/download/private/X ... .10%29.pdf

[henk]

In addition to the check-lists, there is one trivial mistake that I often make: swapping TDI and TDO.

The output from xrun should tell you whether the tools have found the adapter or not. Open a command line window for the tools, and run xrun -l.

If the tools aren't installed properly, or your shell/command line prompt does not have its environment set up correctly you get:

Code: Select all

% xrun -l
-bash: xrun: command not found

(or its windows equivalent)

If there is a problem with the USB drivers or USB cable you will get something like this:

Code: Select all

% xrun -l

Available XMOS Devices
----------------------

  No Available Devices Found

If the XTAG is working fine, but the board is not wired up correctly you get this:

Code: Select all

15:15:09 % xrun -l

Available XMOS Devices
----------------------

  ID	Name			Adapter ID	Devices
  --	----			----------	-------
  0 	XMOS XTAG-2         	Qfq_Jqiv	None

Finally, if it all works you will get a device instead of the 'None':

Code: Select all

% xrun -l

Available XMOS Devices
----------------------

  ID	Name			Adapter ID	Devices
  --	----			----------	-------
  0 	XMOS XTAG-2         	Qfq_Jqiv	O[0]

[fas]

If there is a problem with the USB drivers or USB cable you will get something like this:

Code: Select all

% xrun -l

Available XMOS Devices
----------------------

  No Available Devices Found

This is what I'm getting. I've tried different USB ports but it's always the same response. Could it be because I'm not using the cable included with the XTAG? That cable is too short to reach from the back of my computer to our board. My gut is telling me the included cable is so short because there is a known issue.

[henk]

Hi fas,

Any high speed USB cable will do. If in doubt - just plug it in with the short cable without plugging it into your board (just connect the XTAG to USB), and see if it makes any difference.

Assuming the cable is fine, this is some issue with windows recognising the XTAG. I know preciously little about that, but I am sure there are plenty of others who know how.

What flavour of Windows do you use? There is something about windows 7 on <https://www.xmos.com/support/boards?product=19480>.

Cheers,
Henk

[fas]

Hi fas,

Any high speed USB cable will do. If in doubt - just plug it in with the short cable without plugging it into your board (just connect the XTAG to USB), and see if it makes any difference.

Assuming the cable is fine, this is some issue with windows recognising the XTAG. I know preciously little about that, but I am sure there are plenty of others who know how.

What flavour of Windows do you use? There is something about windows 7 on <https://www.xmos.com/support/boards?product=19480>.

Cheers,
Henk

I'm using Windows 7. I'm aware of the USB 3 problems with Windows 7 so I made sure to use a USB 2 port.

[fas]

So I've tried three different cables, including the short one included with the XTAG, two different XTAG's and six different USB ports. I've tried uninstalling and reinstalling the drivers. I've tried uninstalling and reinstalling the XMOS software. Always the same error: "No Available Devices Found".

What do I do now?

[fas]

Solved.

This issue was even though the ports on the PC are labeled USB 2.0 they are connected to a USB 3.0 root hub. This motherboard (Asus X99 Pro) is strange in that it connects all the USB ports to the USB 3.0 root hub and doesn't use any of the USB 2.0 controllers on the X99 chipset.

[mon2]

Hi fas. Thanks for your positive report. For closure, what was your solution ? Did you locate another host PC with true USB 2.0 ports which is able to detect the XTAG-3 tool ?

[fas]

Hi fas. Thanks for your positive report. For closure, what was your solution ? Did you locate another host PC with true USB 2.0 ports which is able to detect the XTAG-3 tool ?

Both. The first thing I tried was an old laptop running Windows XP. Worked first try. Then I went back to the new PC and set Device Manager to "Display Devices by Connection". That is when I found that the USB 2.0 ports are connected to a USB 3.0 root hub. I then added the environment variable to delay the renumeration and that got things to work.