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usb fails to enumarate

punitha kutti

I developed a firmware for FX2 . I tested it in a board with fx2 and spartan FPGA. It worked fine . Now I want to use the same firmware for another board. Iam using cypress driver. When I download the firmware, the device does not enumarate as cypress sample device , some times it is taking a long time to enumarate . When it does not enumarate either it goes as unknown device or it is not listed in the devices list .Can any one say what is the reason for this . I used the same PID and VID of the previous board . Can I use the same PID and VID.?

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  • 0 in reply to vanitha kutti

    "I changed the port and it is working fine"

    Aha, it was surely a hardware problem, but not on the board :-)



    "How to get the unique PID and VID for my device?"

    a) For temporary use of development,

    you can apply any VID/PID, unless the pair conflicts with existing pairs on your PC. The VID/PID pairs registered to your PC are listed up on this registry key.

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\USB\Vid_????&Pid_????

    Choose a VID which doesn't appear on above registry, for example 0xFFFF.

    Then, search this candidate VID on the registered INF files
    The INF files are held in this folder.

    C:\Windows\inf\

    As the default, this folder is invisible. You'll need to change the folder option to see this folder on the explorer.
    Search the VID string, for example "VID_FFFF", in all .inf files in this folder using an utility like Grep, or multi-file search of your favorite text editor, or Windows search companion (search contents).

    No INF file has the VID string, the candidate VID is free on your PC.
    You can use any PID under this VID.

    b) For production,

    - Buy a VID from USB.org - US$2,000
    www.usb.org/.../

    - USB device manufacturers distribute unique PID under their VID, for sales promotion.
    SiLabs, FTDI, Microchip, etc.

    Tsuneo