Abstract
Coverage evaluation is indispensable for verification via simulation. As the functional complexity of modern design is increasing at a breathtaking pace, it is requisite to take observability into account. Unfortunately, nowadays coverage metrics taking observability into account are not very satisfactory. On the one hand, for the observability assessment algorithms proposed up to now, the overhead of computing is large, so they could not be integrated into simulation tools easily. On the other hand, the vector generation methods involving the metrics taking observability into account are not very efficient, and there exists a disconnection between these metrics and the vector generation process.
In this paper, some original ideas for the problems above are presented. (1) Precise and concise abstract representations from HDL (Hardware Description Language) descriptions at RTL (Register Transfer Level) are presented to model observability information. (2) A novel observability evaluation method based on the proposed models is introduced. This method is more computationally efficient than prior efforts to assess observability and it could be integrated into compilers and simulators easily. (3) A new simulation vector generation procedure involving the observability-enhanced statement coverage metric is developed. The method is simulation-based and driven by the distribution of unobserved statements. During this procedure, the proposed algorithm always tries to cover all unobserved statements, and reduce unnecessary backtracking, so it is efficient. The methods proposed have been implemented as a prototype tool for VHDL designs, and the results on benchmarks show significant benefits.
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This paper is supported in part by the National Natural Science Foundation of China (NSFC) under Grant No. 90207002, and in part by the Foundation of Institute of Computing Technology, Chinese Academy of Sciences (CAS) under Grant No. 20056340.
Wei Lu received the B.Eng. degree from Harbin University of Science and Technology, and the M.Eng. degree from Harbin Institute of Technology in 2000 and 2002 respectively, all in computer science. He is now a Ph.D. candidate in computer science at the Institute of Computing Technology, Chinese Academy of Sciences (CAS). His current research interests focus on VLSI/SoC design verification and test generation.
Xiu-Tao Yang received his B.S. and M.Eng. degrees from Shandong University of Science and Technology in 1999 and 2002 respectively. He is now a Ph.D. candidate at the Institute of Computing Technology, CAS. His current research interests focus on high level test generation.
Tao Lv received the B.Eng. degree from Harbin Engineering University, and the M.Eng. degree from Institute of Computing Technology, CAS, in 2000 and 2003 respectively, both in computer science. Currently, she is a Ph.D. candidate and assistant researcher at Institute of Computing Technology, CAS. Her current research interests include VLSI/SoC design verification, wireless sensor network.
Xiao-Wei Li received his B.Eng. and M.Eng. degrees in computer science from Hefei University of Technology (China) in 1985 and 1988 respectively, and his Ph.D. degree in computer science from Institute of Computing Technology, CAS, in 1991. Dr. Li joined Peking University as a postdoctoral research associate in 1991, and was promoted to associate professor in 1993, all with the Department of Computer Science and Technology. From 1997 to 1998, he was a visiting research fellow in the Department of Electrical and Electronic Engineering at the University of Hong Kong. In 1999 and 2000, he was a visiting professor in the Graduate School of Information Science, Nara Institute of Science and Technology, Japan. He joined Institute of Computing Technology, CAS, as a professor in 2000. His research interests include VLSI/SoC design verification and test generation, design for testability, low-power design, dependable computing. Dr. Li received the Natural Science Award from CAS in 1992, the Appreciation from IEEE Computer Society in 2001. He is a senior member of IEEE. He is an area editor of the Journal of Computer Science and Technology and an associate editor-in-chief of the Journal of Computer-Aided Design & Computer Graphics (in Chinese).
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Lu, W., Yang, XT., Lv, T. et al. An Efficient Evaluation and Vector Generation Method for Observability-Enhanced Statement Coverage. J Comput Sci Technol 20, 875–884 (2005). https://doi.org/10.1007/s11390-005-0875-6
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DOI: https://doi.org/10.1007/s11390-005-0875-6