This library element implements a single-channel DIT FFT using both AI Engine tiles and programmable logic to extract higher performance for larger point sizes. The VSS offers two modes of implementing the FFT: Mode 1 and Mode 2. Mode 1 performs more computation on AIE tiles compared to Mode 2. It also allows finer control over the value of SSR. Mode 2 uses more PL compute resources compared to Mode 1. It also uses less PL memory than Mode 1. The two modes thus offer different trade-offs between performance and resource utilization.