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Unknown USB device (device descriptor request failed) | Cypress Semiconductor

Unknown USB device (device descriptor request failed)

Summary: 2 Replies, Latest post by Farris on 12 Sep 2016 12:31 PM PDT
Verified Answers: 0
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itamar's picture
4 posts


I am using CY8CKIT-050 PSOC 5LP DEV KIT.

I added a USB contoller to my psoc project, by the instrctions of the guide.

and when I connect the communication USB port to my PC and try to install the USB driver, and open the Device Manager, I see that my USB device is defined by:

"Unknown USB device (device descriptor request failed)".

I tried to installed the driver by using usb.inf (after editing this file using the new IDs) and it doesnt help.


I am using Windows 8 and used the INF file from the project directory as written in the instructions.


can someone help me with that?

thanks in advance,


scutifer's picture
Cypress Employee
134 posts

 Your descriptors may be improper i.e some of the fields may not be correct and so the PC had to abort the enumeration at the stage where it gets the device descriptor.


Post your project here and we'll take a look.

Farris's picture
1 post

I'm using the psoc 4L chip for usb (specifically CY8CC4247AZI-L433). When I use the HID example project, it says the same thing ("Unknown USB device (device descriptor request failed)"). I've attached the project. I'm on Windows 10. I haven't found any drivers that seem applicable because is should just be a generic HID driver. Any Suggestions?

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