1 Reply Latest reply on Nov 16, 2011 11:32 PM by anand.srinivasan.asokan

    Problems with DMA transfer on FX3 and CyUSB driver

    silvio.ziegler

      I still encounter instable USB 3.0 connection when using the slave fifo interface http://www.cypress.com/?app=forum&id=167&rID=55620 with auto DMA transfer on the FX3.

         

      Now I found that if I am using the BulkAutoLoop (C++) Example from Cypress together with 2 kByte Packet size per transfer, no data is received the CyUSB driver crashes. At some point no data is received and then the driver crashes. When I send more than 2 kByte per transfer there is no problem. The DMA buffer on the FX3 is set up to 1x1 kByte.

         

      I suspect that there is a problem with the auto DMA transfer on the FX3 since the behavior changes if I use larger DMA buffer size than 1x1kByte. Also I do not see this problems when using manual DMA transfer mode. With larger DMA buffer size, 2 kByte data packets also fail and I need to send 4 or more kByte. At the same time there has to be an issue in the CyUSB driver since it always crashes when no data is received in the BulkAutoLoop example. Sometimes I even need to restart my computer, sometimes it is good enough to reload the FW on the FX3 Eval Board.

         

      I am using the following HW setup:

         

      FX3 Eval Board Revision “May 2011”, Beta3 SDK

         

      OS: Windows 7, 64 bit

         

      USB Host Controller: ASMedia USB 3.0 controller (Asus P8Z68-V Motherboard)

         

       

         

      Thanks for help.

         

       

         

      Regards

         

      Silvio