Retiming is a technique for optimizing sequential circuits. In this paper, we discuss this problem and propose an improved retiming algorithm based on variables bounding. Through the computation of the lower and upper bounds on variables, the algorithm can significantly reduce the number of constraints and speed up the execution of retiming. Furthermore, the elements of matrixesD andW are computed in a demand-driven way, which can reduce the capacity of memory. It is shown through the experimental results on ISCAS89 benchmarks that our algorithm is very effective for large-scale sequential circuits.
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Leiserson C, Saxe J. Optimizing synchronous systems.Journal of VLSI and Computer Systems, 1993, 1(1): 41–67.
Leiserson C, Saxe J. Retiming synchronous circuits.Algorithmica, 1991, 6(1): 5–35.
Ishii A, Leiserson C, Papaefthymiou M C. Optimizing two-phase, level-clocked circuitry. InAdvanced Research in VLSI and Parallel Systems: Proc. the 1992 Brown/MIT Conference, Boston, USA, 1992, pp.246–264.
Lockyear B, Ebeling C. Optimal retiming of level-clocked circuits using symmetric clock schedules.IEEE Transactions on Computer-Aided Design, September, 1994, 13(9): 1097–1109.
Lalggudi K N, Papefthymiou M. DeLa Y: An efficient tool for retiming with realistic delay modeling. InProc. the ACM/IEEE Design Automation Conference, 1995, pp.304–309.
Even G, Spillinger I Y, Stok L. Retiming revisited and reversed.IEEE Transactions on Computer-Aided Design, March, 1996, 15(3): 348–357.
Monteiro J, Devadas S, Ghosh A. Retiming sequential circuits for low power. InProc. the ACM/IEEE International Conference on Computer-Aided Design, Santa Clara, California, USA, 1993, pp.398–402.
Shenoy N, Rudell R. Efficient implementation of retiming. InProc. the ACM/IEEE International Conference on Computer-Aided Design, San Jose, California, USA, 1994, pp.226–233.
Deokar R B, Sapatnekar S S. A fresh look at retiming via clock skew optimization. InProc. the ACM/IEEE Design Automation Conference, San Diego, California, USA, 1995, pp.310–315.
Sapatnekar S S, Deokar R B. Utilizing the retiming skew equivalence in a practical algorithm for retiming large circuits.IEEE Transactions on Computer-Aided Design, October, 1996, 15: 1237–1248.
Maheshwari M, Sapatnekar S S. A practical algorithm for retiming level-clocked circuits. InProc. the ACM/IEEE International Conference on Computer-Aided Design, Dallas, Texas, USA, 1996, pp.440–445.
This work is supported by the National Science Foundation. USA under contract 5978 East Asia and Pacific Program-9602485.
Lu Zongwei received both his B.E. and M.S. degrees from the Department of Automation at Tianjin University, P.R. China in 1995 and 1999, respectively. Currently, he works as an instructor at the VLSI Research Institute, the Department of Electronic Engineering, Shanghai Jiaotong University. His research interests include electronic design automation, VLSI circuits and systems design, low voltage and low power integrated circuits design, RFIC design and combinational optimization.
Lin Zhenghui did his undergraduate work in Shanghai Jiao-tong University, Shanghai, China and received his Ph.D. degree in electronic engineering from the University of Tokyo, Japan. He joined the Department of Electronic Engineering, Shanghai Jiaotong University in 1955, where he is currently a professor. He also holds visiting positions at University of California, Berkeley and the University of Tokyo, Japan. Dr. Lin is the founder and director of the Institute of VLSI at Shanghai Jiaotong University. He is a recipient of a National Science and Technology Award and an Outstanding Contribution Honor, both from the Chinese Government. He has published over 200 papers and seven books in the area of circuits and system theory, VLSI design, verification, testing and fault diagnosis, and discrete-event systems.
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Lu, Z., Lin, Z. & Chen, H. Variables bounding based retiming algorithm. J. Compt. Sci. & Technol. 17, 797–806 (2002). https://doi.org/10.1007/BF02960770
- linear program
- sequential circuits
- digital integrated circuit
- electronic design automation