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Timing analysis for MOSFETS, an integrated approach

Timing and electrical verification is an essential part of the design of VLSI digital MOS circuits. It consists of determining the maximum operating frequency of a circuit, and verifying that the circuit will always produce the expected logical behavior at or under this frequency. This complex task requires considerable computer and human resources. / The classical simulation approach cannot be used to insure the timing and electrical correctness of the large circuits that are now being designed. The huge number of possible states in large circuits renders this method impractical. Worst-case analysis tools alleviate the problem by restricting the analysis to a limited set of states which correspond to the worst-case operating conditions. However, existing worst-case analysis tools for MOS circuits present several problems. Their accuracy is inherently limited since they use a switch-level model. Also, these procedures have a high computational complexity because they resort to path enumeration to find the latest path in each transistor group. Finally, they lack the ability to analyze circuits with arbitrarily complex clocking schemes. / In this text, a new procedure for circuit-level timing analysis is presented. Because it works at electronic circuit level, the procedure can detect electrical errors, and attains an accuracy that is impossible to attain by other means. Efficient algorithms, based on graph theory, have been developed to partition the circuits in a novel way, and to recognize series and parallel combinations. This enables the efficient computation of worst-case, earliest and latest, waveforms in the circuit, using specially designed algorithms. The new procedure extracts automatically the timing requirements from these waveforms and can compute the clocking parameters, including the maximum clock frequency, for arbitrarily complex clocking schemes. / A computer program was written to demonstrate the effectiveness of the new procedure and algorithms developed. It has been used to determine the clocking parameters of circuits using different clocking schemes. The accuracy obtained on these parameters is around 5 to 10% when compared with circuit-level simulations. The analysis time grows linearly with the circuit size and is approximately 0.5s per transistor, on a microVAX II computer. This makes the program suitable for VLSI circuits.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.75459
Date January 1987
CreatorsDagenais, Michel R.
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageDoctor of Philosophy (Department of Electrical Engineering.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 000550387, proquestno: AAINL44472, Theses scanned by UMI/ProQuest.

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