Reducing Compilation Time of Zhong's FPGA-based SAT Solver

Pak K. Chan, M. J. Boyd, S. Goren, K. Klenk, V. Kodavati, R. Kundu, M. Margolese, J. Sun, K. Suzuki, E. Thorne, X. Wang, J. Xu, M. Zhu
Department of Computer Engineering
University of California, Santa Cruz
Santa Cruz, California 95064 USA

Abstract

We present schemes to reduce the compilation time of configurable hardware that solves Boolean Satisfiability. The SAT solver presented by Zhong in last year's FCCM conference has a large compilation time overhead mainly due to placement and routing of many FPGAs. We attack the problem on 3 fronts. First, we partition the SAT solver into instance-specific and non-specific components. Secondly, we transform SAT instances to a canonical form. Finally, we present a board-level architecture to solve large SAT instances. All these efforts amount to a reduction in placement and routing time to configure the reconfigurable hardware. We are able to reduce the compilation time to mere routing time of the implication circuits for each instance of the SAT problem, given the best scenario.