2 Replies Latest reply on Jul 18, 2016 5:32 AM by user_491519953

    GPIO signal synchronized to the GPIF clock input

    user_491519953

      Hi,

         

      I am using GPIF interface as a synchronous slave FIFO input. The transmission is initiated by the FX3 by pulsing a GPIO line. However the trigger signal must be synchronized to the GPIF clock rather than the FX3s main clock in this design. How can I ensure the IO buffer of a spare GPIF CTLx  pin is still using the GPIF clock source after I override it to use it as a simple IO within the firmware?

         

      Cheers,

         

      Helmut

        • 1. Re: GPIO signal synchronized to the GPIF clock input
          nisa

          Helmut, 

             

          Do you want to toggle the using GPIF clock source? Is so, you can do this in the GPIF state machine. You can do a DR_GPIO action to drive the status or toggle the GPIO. Please try.

          • 2. Re: GPIO signal synchronized to the GPIF clock input
            user_491519953

            Thanks Nishant, this what I ended up doing: I added an additional state transition to an idle state which is triggered by the Firmware trigger. While in the firmware triggered state the GPIO output signal is asserted. Now I can produce a GPIF clock synchronous trigger while the GPIF is in this idle state. However I will have to be able to assert this trigger signal independent of the state, as the next measurement should be triggered during transmission of the current measurement. Is there a way to create a second independent state machine for forwarding the firmware trigger, or some neat way to implement this rather than having a firmware trigger asserted copy of each state?