1 Reply Latest reply on Feb 13, 2019 2:44 AM by abhinavg_21

    UVC in both USB 2 and USB 3


      I have an FX3 UVC camera that works in USB 3, but not in USB 2.  What I see is a long set of "clear feature" requests, which of course causes the stream to abort.  As soon as I get the application started, I get a "clear feature" and the application stops.


      I have some questions.  The endPointConfig and the dmaMultiConfig setups in the sample are set only for USB 3 information.  It seems to me that the packet size and the DMA buffer size/count values need to be tailored to the interface speed, but I don't see that in any of the samples.  How is that supposed to work?  The bulk packet size is set to 1024, but for high-speed the bulk packet has to be 512.  Is the API taking care of that for me?


      Does it matter whether the endPointConfig and dmaMultiConfig configuration is done at app init or at app start time?  I've seen it done both ways.

        • 1. Re: UVC in both USB 2 and USB 3



          I assume you are referring to "cyfxuvcinmem_bulk" example that comes along with SDK. I tested this example with USB 2.0 cable and it works fine. But if you want to test change the MACRO

          #define CY_FX_EP_BULK_VIDEO_PKT_SIZE   (0x400)    to 0x200 for USB 2.0 configuration.


          Thanks & Regards
          Abhinav Garg