1 Reply Latest reply on Nov 16, 2018 8:40 PM by SrinathS_16

    Late ACK when using CY7C68001

      Hi,

       

      I'm task with figuring out, why our USB communication randomly is in-stable. In a USB trace I was able to locate the following strange behavior, where the ACK on the setup package seams very late (see image below). I was wondering, under which circumstances is such a behavior can be expected?

       

       

      I'm relative new to such low level debugging and would welcome any hints.

        • 1. Re: Late ACK when using CY7C68001
          SrinathS_16

          Hello,

           

          - What is the request that is sent to the device (bRequest = 0x00 from trace). Please explain what this request corresponds to.

          - Please let us know the USB class that the device conforms to.

          - From the trace, it can be seen that there is no ACK from the device. Kindly, ensure that the class specific request (0x00) is handled in the device's firmware.

           

          EDIT:

          - When designing a class specific device, the requests specific to that class ought to be handled in the firmware appropriately.

           

          Best regards,

          Srinath S