Low-Power and testable circuit synthesis using Shannon decomposition

ABSTRACT

Structural transformation of a design to enhance its testability while satisfying design constraints on power and performance can result in improved test cost and test confidence. In this article, we analyze the testability in a new style of logic design based on Shannon's decomposition and supply gating. We observe that the tree structure of a logic circuit due to Shannon's decomposition makes it intrinsically more testable than a conventionally synthesized circuit, while at the same time providing an improvement in active power. We have analyzed four different aspects of the testability of a circuit: a) IDDQ test sensitivity, b) test power during scan-based testing, c) test length (for both ATPG-generated deterministic and random patterns), and d) noise immunity. Simulation results on a set of MCNC benchmarks show promising results on all these aspects (an average improvement of 94% in IDDQ sensitivity, 50% in test power, 19% (21%) in test length for deterministic (random) patterns, and 50% in coupling noise immunity). We have also demonstrated that the new logic structure can improve parametric yield (6% on average) of a circuit under process variations when considering a bound on circuit leakage.

REFERENCES

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INDEX TERMS

Primary Classification:
  B. Hardware
  B.7 INTEGRATED CIRCUITS
      B.7.3 Reliability and Testing**

General Terms:
Design

Keywords:
Design-for-test, IDDQ, Shannon expansion, dynamic supply gating, noise immunity, test coverage, test power