Timing Verification of Adaptive Integrated Circuits

Abstract

An adaptive circuit can perform built-in self-detection of timing variations and accordingly adjust itself to avoid timing violations. Compared with conventional over-design approach, adaptive circuit design is conceptually advantageous in terms of power-efficiency. Although the advantage has been witnessed in numerous previous works including test chips, adaptive design is far from being widely used in practice. A key reason is the lack of corresponding timing verification support. We developed new timing analysis techniques to fill this void. A main challenge is the large runtime complexity due to numerous adaptivity configurations. We propose several pruning and reduction techniques and apply them in conjunction with statistical static timing analysis (SSTA). The proposed method is validated on benchmark circuits including the recent ISPD'13 suite, which has circuit as large as 150K gates. The results show that our method can achieve orders of magnitude speed-up over Monte Carlo simulation with about the same accuracy. It is also several times faster than an exhaustive application of SSTA.