Part Number: TMS320C6748
Other Parts Discussed in Thread: SYSBIOS
Again, not sure if this is hardware or code related. Probably both but I do not know where to start on either...
Our device is powered from USB 2.0. On powering up it sometimes does not enumerate properly. Windows does not read the vendor_id/hardware_id then the deice is listed as "Unknown Device" with Hardware Id USB/UNKNOWN. Cycling the plug sometimes makes it work, usually not.
Current solution is the "Magic Hub". By plugging the device into an un-powered hub then into the computer, the device typically enumerates correctly. Nobody knows why. I have recreated this problem with a USB analyzer in the mix. Recorded traces show a "Bad Turnaround/Timeout" on an early 18 byte device response packet, part of which includes the vendor_id/hardware_id. Guessing that this error prevents Windows from identifying the device and loading the driver. The device tries to send this packet 3 times, always with an error.
Problem is, I have no idea what this means, what might be the cause, or how to make a fix. And I have no idea who to ask.
Obviously need a USB 2.0 protocol specialist. But where does one find one of those? Anybody want a consulting job?
Any help or suggestions would be greatly appreciated.
