1 Reply Latest reply on Apr 29, 2020 3:52 AM by JayakrishnaT_76

    USBBulkSourceSink stop working after add uart print in Dma Callback

    xixu_4093676

      Hello support,

       

      I try to add  "CyU3PDebugPrint (4, "CyU3PDmaChannelGetBuffer buf_p.size %d\n", buf_p.size);" into CyFxBulkSrcSinkDmaCallback (cyfxbulksrcsink.c  line 227).

      then streamer tools can not get data from IN endpoint.

      By My understand, it maybe get very slow transfer data speed.

      Can you let me know what is reason on the issues?

      for your reference, I also attach my modified code on the offical sample code USBBulkSourceSink.

       

      Thanks,

      Martin

        • 1. Re: USBBulkSourceSink stop working after add uart print in Dma Callback
          JayakrishnaT_76

          Hello,

           

          It is not recommended to use the API CyU3PDebugPrint() inside a callback function. This is because it will delay the processing of DMA interrupts on all channels in the system. This is documented in page 46 of the document Getting started with FX3 SDK which can be found in the following location:

          C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\doc\firmware

           

          Note: This path may change depending on the installation directory of FX3 SDK.

           

          Best Regards,

          Jayakrishna