1 Reply Latest reply on Apr 17, 2019 12:19 AM by HemanthR_06

    USB connection speed change issue




      We have been working on a CX3 based camera with USB Type-B connector. This will be connected to the host through a USB Type-B to Type-A cable. When connected to host’s USB 3.0 port, during USB  enumeration we are getting a CY_U3P_USB_EVENT_CONNECT event with the connection speed as SUPER SPEED.


      After this we are getting the CY_U3P_USB_EVENT_SS_COMP_ENTRY and CY_U3P_USB_EVENT_SS_COMP_EXIT USB events. Followed by the CY_U3P_USB_EVENT_RESET and CY_U3P_USB_EVENT_SUSPEND.

      In the event of above transactions we again get the CY_U3P_USB_EVENT_CONNECT event with the connection speed as HIGH SPEED and continues to work as USB 2.0 device.


      Can anyone explain why there is a change in USB speed after Super speed compliance entry and exit?


      In some scenarios after receiving the CY_U3P_USB_EVENT_SS_COMP_ENTRY event , further we are not receiving any USB event.

      What will be the reason for this behaviour ??



      Thanks in advance



        • 1. Re: USB connection speed change issue

          Hi Indumathi,


          As you might know,  an upstream port shall transition to Compliance Mode upon the 360-ms timer timeout (tPollingLFPSTimeout). So, the link state changes did not occur as necessary for a device enumeration.

          Then the Host might have issued a warm reset and even this time Super Speed connection failed, which led the device fallback to USB2.

          Can you please load USBBulkSrcSink example and collect the UART log so that we can see what's going on with USB3 connection.

          Is it your custom made board?