Lambda Set Selection in Roth-Karp Decomposition for LUT-Based FPGA Technology Mapping

Roth-Karp decomposition is a classical decomposition method. Because it can reduce the number of input variables of a function, it becomes one of the most popular techniques used in LUT-based FPGA technology mapping. However, the lambda set selection problem, which can dramatically affect the decomposition quality in Roth-Karp decomposition, has not been formally addressed before. In this paper, we propose a new heuristic-based algorithm to solve this problem. The experimental results show that our algorithm can efficiently produce outputs with better decomposition quality than that produced by other algorithms without using lambda set selection strategy.