1 Reply Latest reply on Jun 26, 2019 1:46 AM by SrinathS_16

    JTAG and SPI communication issue.




      We are using cypress FX3 DVK for our application and we are facing a major issue of jtag debugger and SPI communication pins.

      As we noticed that the SPI lines used by JTAG (FTDI chip), the same pins are used for SPI communication. Which are connected 220 ohms of resistance.


      And we have remove the resistance of 220 ohms and directly connected to the SPI lines.




      1. We are unable to debug the Cypress DVK using the JTAG debugger which is provided on the board itself after reaching 97% it will display error.

      2.On the MOSI line (SPI) we are observing continues pulses.


      Hoping for the faster replay.

      thank you in advance.



      Harsha A P

        • 1. Re: JTAG and SPI communication issue.

          Hello Harsha,


          - Please let me know the connection of FX3 JTAG lines.

          - Do you mean to say that the FX3 SPI lines are connected to the FTDI JTAG lines?

          - Please refer to the JTAG debugging section on the EzUsbSuite_UG.PDF file from the FX3 SDK.


          EDIT: Ensure that the JTAG lines do not have a pull-up/ pull-down resistor.


          Best regards,

          Srinath S