5 Replies Latest reply on Sep 8, 2014 1:46 AM by vavc

    CY7C68001 SX2 MS OS String descriptor

    rok.vogrin

      Hi,

         

       

         

      I am trying to set a MS OS string descriptor on SX2 to work with WINUSB driver but it doesn't work. 

         

       

         

      How can I set a string descriptor to index 0xEE? I don't see any option to tell SX2 the index of string descriptor.

         

      I also tried to handle a setup packet on my own but SX2 always handled a Get Descriptor on index 0xEE with no response and I didn't get SETUP interrupt or anything else.

         

      How can I fix that? 

         

      Do you have any example for MS OS Descriptor for SX2?

         

       

         

      Thanks for help,

         

      Rok

        • 1. Re: CY7C68001 SX2 MS OS String descriptor
          vavc

          Hi ,

             

           

             

          HOSt asks for the MS OS descriptors only when the device is enumerating for first time in the PC(with a particular VID/PID).From the second time onwards it won't ask the MS OS descriptors.

             

          During the first time if the host doesn;t respond then host won't ask it again as mentioned.

             

           

             

          Are you enumerating the SX2 from the EEPROM or from the external master?

             

           

             

          Regards,

             

          Vikas.

          • 2. Re: CY7C68001 SX2 MS OS String descriptor
            rok.vogrin

             Hi,

               

            I know that the host asks for MS OS descriptors only for the first time, so I uninstalled driver for this device and I deleted its entries in Registry editor. 

               

            Trace of USB activity with USBLyzer showed that request for MS OS descriptor is sent from host but with no response. When MS OS descriptor is requested I don't get SETUP interrupt to handle it on my own, but SX2 handles it itself (with no response).

               

            I am using external master to write descriptors to SX2, but I didn't find any option to write string descriptor with index 0xee.

               

            How can I do that?

               

             

               

            Regards,

               

            Rok

            • 3. Re: CY7C68001 SX2 MS OS String descriptor
              vavc

              Hi Rok,

                 

               

                 

              Please check whether you have enabled the SETUP interrupt or not. During enumeration SX2 will send an SETUP interrupt if it cannot handle the SETUP trasnsfer. Host has to read the SETUP register to know the details about the SETUP transfer.

                 

               

                 

              Regards,

                 

              Vikas,

              • 4. Re: CY7C68001 SX2 MS OS String descriptor
                vavc

                Hi ,

                   

                 

                   

                I am uploading the project in which MS OS string descriptor implementation is done.FX2LP is acting as a external master for SX2.

                   

                 

                   

                PFA.

                   

                 

                   

                Regards,

                   

                Vikas.