Abstract: Fast Fourier transform is adopted in many applications.Through the study of the character of the radix-2 and radix-4 decimation-in-time Cooley-Turkey FFT algorithm,a kind of high performance FFT/IFFT processor is proposed.With the modified radix-4 butterfly unit it can process stride-by-2 permutation.The processor allows conflict-free access of the four operands distributed over (parallel)(memory) modules.Simulation result shows that the processor can be used in many situations demanding high speed and area.