ABSTRACT Automating Post-Silicon Debugging and Repair.pdfVIP

Automating Post-Silicon Debugging and Repair Kai-hui Chang, Igor L. Markov, Valeria Bertacco EECS Department, University of Michigan, Ann Arbor, MI 48109-2121 {changkh, imarkov, valeria}@ ABSTRACT Modern IC designs have reached unparalleled levels of complexity, resulting in more and more bugs discovered after design tape-out However, so far only very few EDA tools for post-silicon debug- ging have been reported in the literature. In this work we develop a methodology and new algorithms to automate this debugging pro- cess. Key innovations in our technique include support for the phys- ical constraints specific to post-silicon debugging and the ability to repair functional errors through subtle modifications of an existing layout. In addition, our proposed post-silicon debugging methodol- ogy (FogClear) can repair some electrical errors while preserving functional correctness. Thus, by automating this traditionally man- ual debugging process, our contributions promise to reduce engi- neers’ debugging effort. As our empirical results show, we can automatically repair more than 70% of our benchmark designs. 1. INTRODUCTION Due to the high complexity of modern designs and the increas- ing pressure to reduce their time-to-market, errors are more likely to escape verification and are only found after a chip has been man- ufactured. Needless to say, such errors must be fixed before the In- tegrated Circuits (ICs) can be shipped to customers, making post- silicon debugging a crucial step in the design process. To this end, a recent EE Times article quotes: “post-silicon debugging is a dirty little secret that can cost $15 to $20 million and take six months to complete” [15]. Indeed, post-silicon debugging has become one of the most time-consuming part, 35% on average, of the chip de- sign cycle [2]. Given that the market window for many modern products is only a few years long, the delay caused by respins can dramatically impact revenues. Therefore, it is surprising that o