12/2008 : Is Asynchronous Logic More Robust than Synchronous Logic?

RR Number

12/2008

Conference

IEEE Transactions on Dependable and Secure Computing

Author(s)

Babak Rahbaran, Andreas Steininger

Abstract

With clock rates beyond 1 GHz the model of a system-wide synchronous clock is becoming difficult to maintain, therefore asynchronous design styles are increasingly receiving attention. While the traditional synchronous design style is well-proven and backed up by a rich field experience, comparatively little is known about the properties of asynchronous circuits in practical application. In the face of increased transient fault rates, robustness is a crucial property, and from a conceptual view the so called ”delay insensitive” asynchronous design approaches promise to be more robust than synchronous ones, since their operation does not depend on tight timing margins, and data are two-rail coded. A practical assessment of asynchronous designs in fault injection studies, however, can rarely be found, and there is a lack of adequate methods and tools in this particular domain. Therefore the objective of this work is (a) to provide a common approach for efficient and accurate fault injection in synchronous and in asynchronous designs, and (b) to experimentally compare the robustness of both synchronous and asynchronous designs. To this end a synchronous 16 bit processor as well as its asynchronous (delay insensitive) equivalent are subjected to signal flips and delay faults. The results of over 489 million experiments are summarized and discussed, and a detailed discussion on the specific properties of the chosen asynchronous design style is given

Bibtex

@article{ rahbaran:2009-12,
  author =       "Babak Rahbaran and Andreas Steininger",
  title =        "Is Asynchronous Logic More Robust than Synchronous Logic?",
  journal =      "IEEE Transactions on Dependable and Secure Computing",
  year =         "2009",
  month =        "Oct."
  volume = 6
  number = 4
  page = {282--294}
}

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