Writing Custom USB descriptors

Question

I am working on a CX3 chip from cypress which has a USB 3.0 connectivity. I need to enumerate the USB to work as a UVC class(video class) and as a serial port simultaneously.

I have seen the USB documents related to the same but those don't clearly explain about how to write one.

The CX3 SDK provides help to generate the USB descriptors for a UVC class but that doesn't give info about how to add the COM port features into it.

So my query is how do you write the descriptor for the same.

Thanks in advance.

Answer 1

Refer to the attached project in this knowledge base article from Cypress - "Using CyU3PDebugPrint API to Send Debug Messages over USB-CDC Interface from FX3 Firmware – KBA231478"

This is a modified version on AN75779. You can compare this project with the original AN75779 appnote firmware available here to see the additions done for adding USB-CDC support in a UVC device.

Hope this helps!