2 Replies Latest reply on Mar 2, 2018 12:53 AM by user_49271930

    DMA trq input timing

    user_300583242

      Hi at all,

       

      I'm trying to terminate a DMA transfer between RAM->VDAC using "trq" pin.

       

      I guess I'm not understanding the timing of "trq" signal with respect to "drq".

      In the DMA component datasheet is reported:

      "...This signal is only used when the channel is trying to transfer data. A positive edge on this line is ignored at other times..."

      I've tried to apply the rising edge of "trq" when "drq" is low or high (changing the delay whit respect to its rising edge) but without success.

       

      I've tried connecting "trq" to a PWM components (sync'ed to another PWM driving "drq") or connecting it to an external pulse generator.

      In both cases the transfer is not affected by "trq" signal.

       

      I can only terminate the transfer calling an interrupt routine in which I call the function...

      CyDmaChSetRequest(   DMA_Chan, CY_DMA_CPU_TERM_TD);

      The interrupt routine is called by PWM or ext pulse generator.

       

      any idea how to make it work properly?