When I simulate my System Generator design, the following error is reported:  <p>"Although the behavior of this block, as configured, could be simulated, it will not be possible to target it to hardware because: <p> --- Cannot be synthesized  and it does not map to cores because the FFT core must be run at the system clock rate" <p>The problem apears when I put a Down Sample block before the FFT inputs, to obtain a zoom effect in simulation. <p>Anybody can help me?