VHDL-Forum

Tom · Gast

Hi all,

I am currently testing a Xilinx coregen 256-FFT (piplined one) in Modelsim.
I tested descrete sine and pseudo random noise at input side- values in frequency domain come out very strange.
For sine should be one peak but I receive many peaks.
For noise there should be nothing but there are also many peaks.
Of course I was aware of the twos complement values but it doesn't seem to work...
What could be wrong?