The design of the back-end IFFT-256 is a simplified version of the front-end design. It merely implements the transform and the zero-padding – there is no point-wise twiddle multiplications. The graph looks nearly identical to the front-end design shown earlier. The figure below shows the physical array view of the back-end design. It also uses I/O buffers and requires a memory footprint that spills over to the neighboring tile.