Abstract
Boolean Satisfiability (SAT)-based routing has unique advantages over conventional one-net-at-a-time approaches such as simultaneous net embedding or routability decision. Yet SAT-based routing has been criticized for scalability issues. On the other hand, geometric search routing algorithms, even with extensive rip-up-reroute capabilities, have difficulty achieving routing solution convergence when a problem has tight routing constraints. In this paper, we revisit the SAT-based routing idea for FPGA routing, and propose a new hybrid algorithm that integrates SAT-based FPGA routing with a conventional geometric search FPGA router. The advantages of such a combination are two- fold: 1) the scalability handicap of SAT-based routing is overcome due to the path pruning techniques of the geometric search algorithm, and 2) more concrete routability decisions can be made thus achieving the convergence, because the SAT-based technique considers simultaneously any paths in the history of iterative routings. The proposed algorithm named search-SAT is implemented and applied to real-world industry circuits. Preliminary experimental results show “search-SAT” is a more viable routing technique than any earlier SAT- based routing approach.
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References
V. Betz and J. Rose, “VPR: A New Packing, Placement and Routing Tool for FPGA Research,” the Seventh Annual Workshop on Field Programmable Logic and Applications, pp.213–222, 1997.
S. Brown, J. Rose, and Z. G. Vranesic, “A Detailed Router for Field Programmable Gate Arrays,” IEEE Transactions on CAD, pp. 620–628, vol. 11, no. 5, May 1992.
S. D. Brown, R.J. Francis, J. Rose, and Z.G. Vranesic, Field Programmable Gate Arrays, Boston, Kluwer Acad. Publishers, 1992.
M. R. Garey and D. S. Johnson, Computers and Intractability: A Guide to the Theory of NP-Completeness, W.H.Freeman and Company, 1979.
A. Hashimoto and J. Stevens, “Wire Routing by Optimizing Channel Assignment within Large Apertures”, Proceedings of 8th Design Automation Conference, pp. 155–169, 1971.
G. Lemieux and S. Brown, “A Detailed Router for Allocating Wire Segments in FPGAs,” Proc. ACM Physical Design Workshop, California, Apr. 1993.
J. P. Marques-Silva and K. A. Sakallah, “GRASP: A Search Algorithm for Propositional Sat-isfiability”, IEEE Transactions on Computers, vol. 48, no. 5, May 1999.
L. E. McMurchie and C. Ebeling, “PathFinder: A Negotiation-Based Path-Driven Router for FPGAs,” Proc. ACM/IEEE Intl. Symposium on Field Programmable Gate Arrays, Feb. 1995.
G.-J Nam, S. Kalman, J. Anderson, R. Jayaraman, S. Nag and J. Zhuang, “A Method and Apparatus for Testing Routability”, U.S. patent pending.
G.-J Nam, K. A. Sakallah, and R. A. Rutenbar, “Satisfiability-Based Layout Revisited: Detailed Routing of Complex FPGAs Via Search-Based Boolean SAT”, Intl. Sym. on FPGAs, Feb. 1999.
G.-J Nam, F. Aloul, K. A. Sakallah and R. A. Rutenbar, “A Comparative Study of Two Boolean Formulations of FPGA Detailed Routing Constraints”, Intl. Symp. on Physical Design, April 2001.
R. G. Wood and R. A. Rutenbar, “FPGA Routing and Routability Estimation Via Boolean Satisfiability,” IEEE Transactions on VLSI Systems, pp. 222–231, June 1998.
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Nam, GJ., Sakallah, K., Rutenbar, R. (2002). Hybrid Routing for FPGAs by Integrating Boolean Satisfiability with Geometric Search. In: Glesner, M., Zipf, P., Renovell, M. (eds) Field-Programmable Logic and Applications: Reconfigurable Computing Is Going Mainstream. FPL 2002. Lecture Notes in Computer Science, vol 2438. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-46117-5_38
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DOI: https://doi.org/10.1007/3-540-46117-5_38
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