1 Reply Latest reply on Jan 18, 2018 9:33 PM by mddd

    Stupid question. How to use input PCLK with GPIF?  How to configure with code?

    user_463759797

      I have looked and googled and read.  During my searches I have seen some other requests for this type of information without answers from several years ago.

       

      All of the documentation seems to assume I already know how this part of the FX3 works.  I don't, and I can't find it.

       

      I want to supply the PCLK from a PSOC 5 bus clock (done, 24mhz output) into the PCLK input.

       

      I have not found any information on what code I need to do to make PCLK an input *and* force the GPIF state machine to *use* that input as its clock.

       

      I have not found *any* information on how to use the tools to make PCLK go *into* the FX3 and be used *instead* of the internal GPIF PCLK generator.  There is an "external" clock button in the GPIF II designer.  However, there is no information on what configuration to do int code to the GPIF pin to make it be the PCLK input, and then configure that input to feed the FX3 fabric as its clock source for the FX3 state machine / DMA transfer.

       

      In the Superspeed example there is *code* to make GPIF an *output* from the internal GPIF PCLK generator  but no explanation of how to make it an input and use that input as the clock instead.  Since there is code that appears to be required to configure

       

       

      Is it possible to do this?  What am I missing?

       

      if not, is there a way to configure the PSOC 5 EMIF to use an external clock rather than the bus clock?  I did not see where I could do that.