J-Link no USB enumeration

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Max. 10 J-Links enumerate

When connecting multiple J-Links to USB 3.0 ports + hubs, it can happen that Windows only enumerates up to 10 J-Links and then throw enumeration errors. Depending on the USB setup, it may also be only 8 or 9 J-Links that are enumerated. This is not a problem in the J-Link USB driver, but a limitation of the USB 3.0 controller, as the error message indicates:

24JLinks USB30 Error.jpg

Sample setup with error

The following shows a sample setup which produces such an error

24JLinks USB30.png

Sample setup workaround

The following shows a sample setup which workarounds the problem and let Windows enumerate all J-Links

24JLinks USB2.png