Tech Report CS-89-43

Improved Methods for Modeling Uncertainty in RC Timing Analysis

Cheryl L. Harkness and Daniel P. Lopresti

November 1989


Uncontrollable variations in the fabrication process make it impossible to accurately predict the circuit parameters used in timing analysis. Instead, these values are known to fall within certain limits, resulting in a range of possible circuit behaviors. In this paper, we present two new interval-based techniques for computing best- and worst-case bounds on circuit delay. Both produce tighter bounds than an approach we described in an earlier paper. When compared to Monte Carlo simulation, all of the interval methods are more precise and significantly faster.

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