4 Replies Latest reply on Jun 25, 2019 6:51 AM by ehka_4302626

    FX2LP not responsive after changing VID/PID



      I'm a newbie in Cypress world. I have a custom board with FX2LP chip. I changed the VID/PID which is saved on the onboard EEPROM. After that I can't connect to the board neither can I install the Cypress driver for windows 10. When I connect the board to PC, it's recognized as Unknown Device and when I try to install the driver, it says that the driver is not compatible with the device. When I connect the board to Ubuntu it's not recognized at all.

      How can I change the VID/PID to the original value? Or how can I connect to the board again?

      Thank you.

        • 1. Re: FX2LP not responsive after changing VID/PID

          When you changed the VID/PID from the default, you must provide a device driver corresponding to the VID/PID.


          For example, the FX3 SDK provides a device driver file "cyusb3.inf"  In that file several VID/PID pairs are recorded like following.


          ;%VID_XXXX&PID_XXXX.DeviceDesc%=CyUsb3, USB\VID_XXXX&PID_XXXX
          %VID_04B4&PID_00F0.DeviceDesc%=CyUsb3, USB\VID_04B4&PID_00F0
          %VID_04B4&PID_00F1.DeviceDesc%=CyUsb3, USB\VID_04B4&PID_00F1
          %VID_04B4&PID_00F3.DeviceDesc%=CyUsb3, USB\VID_04B4&PID_00F3
          %VID_04B4&PID_4720.DeviceDesc%=CyUsb3, USB\VID_04B4&PID_4720
          %VID_04B4&PID_00B0.DeviceDesc%=CyUsb3, USB\VID_04B4&PID_00B0


          If you add some lines containing your own VID/PID, the device driver can be used for your device for old Windows operating system.


          But it may not be accepted by new Windows like Windows 10 because of a security protection.


          I recommend to use the original VID/PID while you are doing experiments.




          • 2. Re: FX2LP not responsive after changing VID/PID

            Thank you very much for you answer.


            I removed (physically) the EEPROM chip from my board. Then connected the board to my PC and it's recognized as Cypress NO EEPROM Device.

            Now I wonder if I can write the EEProm using another MCU and solder it back on the board?

            • 3. Re: FX2LP not responsive after changing VID/PID

              I recommend to add a jumper or a switch at the SDA line.


              The evaluation board CY3684 has a switch at the SDA line as follows.


              CY3684 EZ-USB FX2LP Development Kit


              The EEPROM can be disconnected by the SW2 from the SDA line not to be accessed by FX2LP.

              When you want to update the EEPROM contents,

              0) turn off the power supply

              1) disconnect EEPROM from the SDA line

              2) turn on the power supply to boot as FX2LP bootloader

              3) connect EEPROM to the SDA line

              4) Rewrite the EEPROM from a utility tool like CyConsole


              Please refer the document "EZ-USB® Development Kit User Guide, Doc. # 001-66390" for more details.  The document can be downloaded from the evaluation kit page.




              • 4. Re: FX2LP not responsive after changing VID/PID

                Hi Noriaki,

                Thank you for your guide. I did exactly what you said & was v\able to solve my problem.

                The jumper on the SDA line, between the chip and the MCU helped me to use the CyConsole and rewrite the VID/PID.

                Thank again