On area/depth trade-off in LUT-based FPGA technology mapping

In this paper, we study the area and depth trade-off in lookup-table (LUT) based FPGA technology mapping. Starting from a depth-optimal mapping solution, we perform a sequence of depth relaxation operations and area-minimizing mapping procedures to produce a set of mapping solutions for a given design with smooth area and depth trade-off. As the core of the area minimization step, we have developed a polynomial time optimal algorithm for computing an area-minimum mapping solution without node duplication for a K-bounded general Boolean network, which makes a significant step towards complete understanding of the general area minimization problem in FPGA technology mapping. The experimental results on MCNC benchmark circuits show that our solution sets outperform the solutions produced by most existing mapping algorithms in terms of both area and depth minimization.<>