A false-path aware Formal Static Timing Analyzer considering simultaneous input transitions

Timing closure has always been the biggest bottleneck in the modern VLSI design flow. Traditional timing verification techniques such as Static Timing Analysis (STA) are usually too conservative or sometimes too optimistic. This inaccuracy may lead to an unnecessary procrastination of time to market or even silicon failure. It is mainly due to the inability to detect false paths and handle multiple-input-transitioning effects in the timing analysis process. In this paper, we proposed a novel Formal Static Timing Analysis (FSTA) technique which can model the multiple-input transitioning effects, detect the false paths, and generate an input transition pattern for the true critical path at the same time. This is achieved by tightly integrating a state-of-the-art Boolean Satisfiability (SAT) solver with a STA engine, under a specialized multiple-input-transition timing library. Our experiments compare the FSTA engine with the traditional STA and random simulation techniques. The results show that our approach greatly outperforms random simulation while obtaining more accurate timing analysis results than STA.

[1]  David Blaauw,et al.  Slope propagation in static timing analysis , 2002, IEEE Trans. Comput. Aided Des. Integr. Circuits Syst..

[2]  Alexander Saldanha,et al.  Timing analysis with implicitly specified false paths , 2000, VLSI Design 2000. Wireless and Digital Imaging in the Millennium. Proceedings of 13th International Conference on VLSI Design.

[3]  Jyuo-Min Shyu,et al.  A new approach to solving false path problem in timing analysis , 1991, 1991 IEEE International Conference on Computer-Aided Design Digest of Technical Papers.

[4]  Jacob A. Abraham,et al.  A quick and inexpensive method to identify false critical paths using ATPG techniques: an experiment with a PowerPC/sup TM/ microprocessor , 2000, Proceedings of the IEEE 2000 Custom Integrated Circuits Conference (Cat. No.00CH37044).

[5]  Noel Menezes,et al.  A multi-port current source model for multiple-input switching effects in CMOS library cells , 2006, 2006 43rd ACM/IEEE Design Automation Conference.

[6]  Robert K. Brayton,et al.  Timing-safe false path removal for combinational modules , 1999, 1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051).

[7]  Massoud Pedram,et al.  A Current Source Model for CMOS Logic Cells Considering Multiple Input Switching and Stack Effect , 2008, 2008 Design, Automation and Test in Europe.

[8]  Jacob A. Abraham,et al.  Full chip false timing path identification: applications to the PowerPC/sup TM/ microprocessors , 2001, Proceedings Design, Automation and Test in Europe. Conference and Exhibition 2001.

[9]  Melvin A. Breuer,et al.  A new gate delay model for simultaneous switching and its applications , 2001, DAC '01.

[10]  David Hung-Chang Du,et al.  On the General False Path Problem in Timing Analysis , 1989, 26th ACM/IEEE Design Automation Conference.

[11]  Karem A. Sakallah,et al.  Modeling the effects of temporal proximity of input transitions on gate propagation delay and transition time , 1996, DAC '96.

[12]  Yi Zhu,et al.  Improving the efficiency of static timing analysis with false paths , 2005, ICCAD-2005. IEEE/ACM International Conference on Computer-Aided Design, 2005..

[13]  Hans Martin Lipp,et al.  Timing verification: a new understanding of false paths , 1992, [1992] Proceedings The European Conference on Design Automation.

[14]  Jacob A. Abraham,et al.  False timing path identification using ATPG techniques and delay-based information , 2002, DAC '02.

[15]  Kwang-Ting Cheng,et al.  False-path-aware statistical timing analysis and efficient path selection for delay testing and timing validation , 2002, DAC '02.