Improvements to technology mapping for LUT-based FPGAs

Abstract

The paper presents several improvements to state-of-the-art in FPGA technology mapping exemplified by a recent advanced technology mapper DAOmap [Chen and Cong, ICCAD '04]. Improved cut enumeration computes all K-feasible cuts without pruning for up to 7 inputs for the largest MCNC benchmarks. A new technique for on-the-fly cut dropping reduces by orders of magnitude memory needed to represent cuts for large designs. Improved area recovery leads to mappings with area on average 7% smaller than DAOmap, while preserving delay optimality when starting from the same optimized netlists. Applying mapping with structural choices derived by a synthesis flow on average reduces delay by 7% and area by 14%, compared to DAOmap.