6 Replies Latest reply on Nov 3, 2016 5:47 AM by wilfried.walezack_1926086

    Questions regarding CYUSB3304

    myphones691_1585041

      Hello, I'm using this hub with one US from a computer and two DS's which I locally power supply, and therefore don't need any of the features ghost charge& ACA-Dock. I also want to configure the hub through internal ROM configuration in order to save an external EEPROM.

         

      From the datasheet I can see ACA-Dock is not supported by my selected device but ghost charge is. The default configuration enables the ghost charge, and I can't disable it when using internal ROM. I want to know what are the implications on my design? how do I need to connect VBUS_US & VBUS_DS? can I connect them to a local 5V DC-DC? can I leave them floating? I also doesn't need the OVRCURR& PWR_EN , can I leave theme floating? 

         

      I also don't fully understand the concept of Embedded_Hub, what is the default level using an internal ROM and what are the implications on the US? in the CY4609 evaluation board, the VBUS_US is connected to a local 5V through 2 10K  resistors voltage divider (why?) to turn the HX3 to work as Embedded hub, why is that?

         

      Thank you for your answer.

        • 1. Re: Questions regarding CYUSB3304
          gsns

          Hi Dan,

             

          Q)how do I need to connect VBUS_US & VBUS_DS?

             

          A) Connect the VBUS_US to VBUS of the host. VBUS_US is used to detect the connection from host. For normal operation VBUS_DS should be connected to local 5V supply.

             

          Q)can I connect them to a local 5V DC-DC? can I leave them floating?

             

          A) connect VBUS_DS to local 5V. don't leave it floating.

             

          Q) I also doesn't need the OVRCURR& PWR_EN , can I leave theme floating? 

             

          A) OVRCURR pins should be pulled high and PWR_EN can be left floating.

             

          The purpose of divider network on VBUS_US pin is to discharge VBUS faster in case of a disconnection event.

             

          Please refer to the app note in teh link given below: 

             

          http://www.cypress.com/file/140751/download

             

           

             

          Thanks,

             

          Krishna.

          • 2. Re: Questions regarding CYUSB3304
            myphones691_1585041

            Thank you.

               

            What is I2C address of the hub when configuring using external master? I couldn't find it on the datasheet nor the HX3 HW design guidelines.

               

            When configuring the hub using the internal ROM, is it still possible to read registers from the I2C master (processor, FPGA etc.) during normal operation? or do I need to change the boot sequence to I2C master in order for the host to read registers during normal operation?

            • 3. Re: Questions regarding CYUSB3304
              dhritiman.kashyap

              I2C slave address(7 bits) by default is 0x60. If you are enabling Pin strapping then the I2C slave address will depend on how you strap the I2C_DEV_ID pin. Refer to Table 6 on the HX3 datasheet.

                 

              It is not possible to read the HX3 registers by an external FPGA or processor in any of the boot modes. The USB hubs generally has an interrupt endpoint which the host will keep on polling to know thw status of the hub/downstream ports of the hub. 

              • 4. Re: Questions regarding CYUSB3304
                myphones691_1585041

                So I don't understand how can you read information like product&vendor ID from the hub. Where can I find application notes explaining this polling process?

                   

                Thank you in advance.

                • 5. Re: Questions regarding CYUSB3304
                  dhritiman.kashyap

                  The host does this by GET_DEVICE_DESCRIPTOR requests to the hub. Refer to Chapter 10 of the USB 3.1 spec.

                  • 6. Re: Questions regarding CYUSB3304
                    wilfried.walezack_1926086

                    Dear supplier,

                       

                    I'm  designing currently a USB 3.0 Hub with this component CYUSB3304.

                       

                    I have already purchased and tested  the development board CY4609, and it's working well.

                       

                    For my hub , i want to use the 5V DC of the UpStream for powered the usb component and 2 DownStream ports. So no need external 5V.

                       

                    Do you have any recommendations for self powered the Hub?

                       

                    Best regards.

                       

                    wilfried