Synopsys, Inc.

Alexei Svizhenko

Arindam Chatterjee

Arthur Nieuwoudt

Joseph Gregory Rollins

A method for floating node reduction uses a capacitance matrix that specifies coupling capacitances between signal nodes and floating nodes of an interconnect structure. Random walks are performed from a first signal node to the other signal nodes, wherein each of the random walks traverses one or more of the floating nodes. Each of the random walks is directed based on probabilities derived from the coupling capacitances of the capacitance matrix. A count is maintained for each of the other signal nodes, wherein each count specifies a number of the random walks that end on the corresponding signal node. The indirect coupling capacitance from the first signal node to a second signal node is selected to correspond with the total indirect coupling capacitance of the first signal node, times the count associated with the second signal node, divided by the total number of random walks.

Floating node reduction using random walk method

A method for performing parasitic capacitance extraction of an integrated circuit (IC) design includes: defining a Gaussian surface around an origin net of the IC design; partitioning the Gaussian surface into a plurality of regions; performing an initial plurality of random walks from each region using a Monte Carlo field solver; and dynamically allocating an additional plurality of random walks among the plurality of regions, wherein the allocation is based on statistical errors associated with the initial plurality of random walks for each of the regions. Results from the random walks are averaged to estimate parasitic capacitance of the origin net. The method may include performing the random walks for each region in pairs, wherein a first random walk of the pair is selected in accordance with an anti-symmetric probability function, and a second random walk of the pair is antithetic to the first random walk of the pair.

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San Jose, CA, United States of America

Alexei Svizhenko