2 Replies Latest reply on Sep 25, 2016 8:55 AM by fabrizio.beltrandi

    manual mode endpoint and slave fifo

    fabrizio.beltrandi

      hi,

         

      I have a FX2LP configured in slave fifo (with an external device that is reading data). I have endpoint 2 and 4 configured as bulk endpoint in manual mode, with buffered 2x of 512 byte length.

         

      I would know if when 8051's FX2LP is accessing fifo data - before commit packet - is a safe practice, even if external device is reading data from slave fifo. 8051 checks fifo empty flag before accessdata,  and external device checks hardware empty flag before read data from slave fifo.

         

      What is the point of view of Cypress? Is there something to do for safety?

         

      Best Regards

         

      begos

        • 1. Re: manual mode endpoint and slave fifo
          madhul_36

          Hi,

             

          What do you mean by FX2lp accessing fifo data - before commit packet. Are you trying to process the data on the fifo before it is read by the external device?

             

          If so, it is fine. If not, please elaborate your application.

             

          Regards,

             

          - Madhu Sudhan

          • 2. Re: manual mode endpoint and slave fifo
            fabrizio.beltrandi

            Hi,

               

            I mean that I am processing data before committing packets (with instructions OUTPKTEND = 0x04 for ep4 for example...). External device is continuously sampling empty fifo flag, and is reading from slave fifo only when empty flag is not true. I have understood that, operating in manual mode, external device see fifo empty until 8051 commits packet writing on OUTPKTEND register. Am I correct?

               

            Best Regards,

               

            Begos