Trouble with XTAG3

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samrjavs
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Trouble with XTAG3

Post by samrjavs »

I was working on a project using an XTAG3 on a custom board using an XS1-U8A-64-FB96. Before this problem occured I was able to download programs to the board and to step through it in debug mode in xTIME Composer so I believe everything was working and that the board layout must be ok.

Now I cannot debug the board using the XTAG3. When I use the "xflash -l" command it says "No Available Devices Found". The LEDs on the XTAG3 are behaving strangely. D7, the power LED, is on strong green. All of the other LEDs are on but very dim. For the LEDs that have a red and a green LED, both are on but very dim. I attached a picture of the board so you can see the LEDs but it may be difficult to make out. The LED behavior is the same whether the XTAG is plugged into the board or not.

I am running Windows 10 and if I open device manager I see the XTAG listed as XMOS XTAG-3 so it seems like the driver might be ok. In another thread I saw a suggestion to add an environment variable called "XMOS_XTAG_WINDOWS7_STARTUP_TIME" with a value of 500, but when I tried that it had no effect. I have tried rebooting my PC but that also didn't do anything.

The only thing I can think of that may have caused this is that I tried an "xflash --erase-all" command before this started happening, and I'm wondering if somehow I damaged the firmware on the XTAG itself? I searched but couldn't find any way to update or reinstall the XTAG firmware for the XTAG3.
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mon2
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Post by mon2 »

Do you recall if any changes were made to the hardware or software tools before this issue surfaced ?

The following thread may be on topic and is worth reading and testing:

https://www.xcore.com/forum/viewtopic.php?f=44&t=2497

Also, open your device manager and confirm the XTAG-3 tool is present. Then remove the XTAG-3 tool and the device manager should dynamically also remove this USB function. Then re-insert into the same USB port and the USB function should appear. This will confirm that the hardware is emitting the required USB IDs to the host PC and the host PC is reading and then pairing the required device driver. That is, the XTAG-3 tool is working and spitting out the required USB traffic to allow for the port to be listed in your device manager tree. Perhaps you can erase the firmware on the XTAG-3 tool but this test confirms that at least the boot loader is still working on the tool. Suggesting that you remove the tool and the seat into another free USB port and this port should be direct on the PC (no USB hubs). The above thread suggests to actually right mouse click and remove / uninstall the USB port while it is docked and then unplug and plug into the USB port so that the XTAG-3 tool is freshly detected (enumerated). It is a goofy work around for some PCs as the same issue was raised on StartKits. Personally not aware if XMOS ever did release the firmware for the XTAG-3 tool but do recall a FAE noting that XTAG-2 firmware is available if you wish to build your own. Just the same, another XTAG-3 is not so costly so for the about $20 USD you may be wiser to source another to confirm the operation of this tool.

Finally, which xTimeComposer version are you using ? Have you tested with older releases of operating systems ? xTimeComposer ? These are only ideas. XMOS or someone needs to throw these permutations onto an USB bus analyzer to nail this fairly common quirk sooner than later. We have these tools in our lab but just not enough time to take on the task. Over the "holidays" will see if we can log the traffic on the XTAG-3 to see if we can view the faults.

Oddworld
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Post by Oddworld »

Hi

Exactly the same issue for me.

I got 2 XTAG3 and they suddently stoped working 2 weeks ago without changing anything on my computer configuration.

Both are still detected by wTIMEcomposer and windows (7) but I have the message "No Available Devices Found". as soon as I try to use them.

Hopefully I have a working  XTAG2 in the meantime but I would like to solve this issue.

 

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mon2
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Post by mon2 »

On the XTAG3 tools which fail to work, is the XTAG3 hardware detected by the xTimeComposer s/w ? Having Windows detect (enumerate) the XTAG3 is a good start but only validates the USB side of the onboard XMOS processor (ie. USB PHY + CPU + related XMOS supplied USB state machine). It is possible the issue is on the XTAG (JTAG) side of the interface.

Detach the XTAG3 hardware from your target board and remove the USB connection from the PC then re-attach -> does the xTimeComposer s/w detect the attached XTAG3 adapter ?

If the above works to enumerate the XTAG3 tool, can you attach the same XTAG3 tool onto an official XMOS dev board to see if the toolchain can function with a different target board ? Wondering if the issues being raised are related to the target designs.

What is the length of the attached USB cable ? We recall that the XCORE-200 kit was supplied with relatively short cables (about 6" in length) and XTAG3 is most likely a High Speed (480 Mbps) USB interface. The quality of the cables will be a factor but enumeration of the adapter itself is not performed at the high speeds of the USB spec.

Does your target design use a supported FLASH device ? XN file properly maps this applied flash device ? Do you have a logic / bus analyzer ? The flash devices are SPI interfaces so you could monitor the activity of the flash devices to see if the XTAG3 tool is generating any activity onto the respective SPI pins.

A logical approach is to confirm if the XTAG3 tool is functional with a known reference kit from XMOS before migrating onto your target custom board. Share more details if you can on your target design. Which CPU ? Voltage rails stable and sequenced properly ? Properly strapped mode pins ? Ample current support for your power supply ? Unless your configuration is damaging the I/O pins on the XTAG3, the XTAG3 tool should be able to function.

Is the XTAG3 tool mating directly with a similar 0.1" spaced box header connection on your target PCB ? Or is there some extension cable between the XTAG3 and the target custom XMOS board ?

 

baffless
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Joined: Tue Feb 23, 2021 12:27 pm

Post by baffless »

Hi, the same problem. Just my xTAG3 is completely new and doesn't work the same way as described. Any solution?