3 Replies Latest reply on Feb 21, 2016 9:18 PM by qinyi.wang

    Problem about communication with FPGA via USB 3.0

    qinyi.wang

      Dear all,

         

      My project is about communication between PC and FPGA. Previously, all things works well. However, this afternoon, the system broke down suddenly. When debugging, I found that I cannot implement loopback example (from AN65974) any more, which always succeeded previously. However, when I connect FX3 to USB2.0 ports, it still works.

         

      Then I wonder if a certain pin of USB3.0 failed. So I test the bulkloopauto example via USB3.0 port. It still works. I have no idea where is the problem, could someone give me some suggestions to narrow down the problem.?

         

      Thank you very much.

         

       

         

      Best Regards

         

      Zoe

        • 1. Re: Problem about communication with FPGA via USB 3.0
          Madhu Lakshmipathy

          Hi,

             

          I am wondering if FX3 had gone into low power mode in USB 3,0. Can you please add the API CyU3PUsbLPMDisable(); in the firmware after the CyU3PConnectState API and see?

             

          Regards,

             

          - Madhu Sudhan

          • 2. Re: Problem about communication with FPGA via USB 3.0
            qinyi.wang

            Hi,

               

            Thank you very much for your kindly reply. Yesterday, I tried again all previously succeeded examples between FPGA and FX3, neither connecting to USB 2.0 port nor connecting to USB 3.0 port can succeed any more. However, the bulkloopauto example can still work, both through USB 2.0 port and USB 3.0 port. By the way, the firmware I used is the one provided in the AN65974. Anyway, I will try your suggestion first.

               

            Thank you again.

               

            Best Regards

               

            Zoe

            • 3. Re: Problem about communication with FPGA via USB 3.0
              qinyi.wang

              Hi,

                 

              I have tried your suggestion, but it did not work. And I tried to catch all the control signals, I found that there was something strange of empty and partial empty flags of the U2P DMA channel. When I have not transfered any data from PC to FX3, the flags indicates the DMA channel is not empty. Do you have any ideas that what causes the flags wrong? The bulkloopauto example still works well. I do not think the FX3 broke. Also, I have tested my FPGA, it also works properly.

                 

              Thank you very much.

                 

               

                 

              Best Regards

                 

              Zoe