Methodology of logic synthesis for implementation using heterogeneous LUT FPGAs

Abstract

Logic synthesis method for heterogeneous LUT FPGAs implementation is proposed As all example, XILINX4000 architecture is considered. The method takes XILINX4000 architectural features (heterogeneous LUTs of 3 and 4 inputs) into account and includes two step decomposition. In the first step, two-level logic representation is transformed into a graph of at most 4 fanin nodes (after this step, each node can be mapped onto 4 input LUT). In the second step, selected 4 fanin nodes are re-decomposed into 3 fanin nodes to ensure mapping onto 3 input LUTs. Re-decomposition task is formulated as substituting node two fanins for exactly one fanin.