Hi all,

My design uses Xilinx's FFT LogiCORE IP which I use to do FFT of transform length 128 points. I configure the IP core in Vivado GUI, instantiate in my code and it works very well. Now my requirement is to configure the IP core dynamically to select either 128 or 512 points. According to the AMD's PG109 document, we can configure the core attributes through "s_axis_config_tdata" in the code. when I do so, the core is performing only 512 points FFT no matter how you configure this attribute. 

Is there anyone who has done any research on this would be helpful!

Thank you 

set fft_config_data to X"FF09" for 512, for others see user guide then apply this process

    process(clk)   

    begin

      if rising_edge(clk) then

        fft_config_rdy_d <= fft_config_rdy;  --s_axis_config_tready

        s_axis_config_tvalid  <= fft_config_rdy and not fft_config_rdy_d;

      end if;

    end process;