3 Replies Latest reply on Sep 2, 2018 10:51 PM by SananyaM_56

    FX2 dropping packets of data


      I have created a device that takes data generated and returns it to the PC.  The data has a numbered sequence in it to allow us to know if we have data loss.  Sometimes the device works well not dropping any data for long lengths of time.  Other times it will dribble data, this is with the same hardware and same PC and App.  Can you offer any advise as to how to get the data drop to cease?

        • 1. Re: FX2 dropping packets of data

          Hello Chris Hawthorne,


          - Please let me know if the data is transferred from an FPGA or external device to the FX2 and then to the host PC. If this is the case, kindly, probe the IFCLK, SLWR and the data lines.

          - Also, let me know if you are using a host application provided by Cypress or is it your own custom application.

          - Kindly, capture the USB traces using either a hardware analyzer like LeCroy or software analyzer like USBLyzer.


          Best regards,

          Srinath S

          • 2. Re: FX2 dropping packets of data

            The device generates 16 bytes of data at 11Khz using a Bulk USB transfer.  Each of the 16 Bytes or a line of data as we see it from the application, has significance.   Two 16 bit bytes connect to our ADC while the others connect to various data points including a RTC and a line counter.  This is how we know we are dropping data.  We have generated our own software.  Sometimes depending on the computer used it will run hours without a drop.  Other times it will dribble a bit of data.  The data accuracy is above 99% but the client would like to see if we can get it better since we typically drop 512 bytes at a time which is 32 lines of data on the screen..  Is there a secure way I can have one of the support engineers at Cypress review the firmware code and the software calls to see if there is something that can be optimized to get a little better yield? We have had issues in the past with data drop and Vikas was able to help.  I can send a link to the case if needed.

            • 3. Re: FX2 dropping packets of data

              Hi Chris,


              As tested, your firmware is fine; please update the latest version of the driver and library files from the FX3 SDK for optimizing your data transfers.


              Best Regards,