Patent · US Expired

Method and system for combinational verification having tight integration of verification techniques

US6308299A · kind A · utility

32Cited by
9References
30Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 17, 1998
Grant dateOct 23, 2001
Priority date
Expiry dateJul 17, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F30/3323
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A method and system for combinational verification tightly integrates multiple verification methods. The present invention performs random simulation on the inputs of two combinational netlists. The nets within the netlists are described as BDDs and divided into classes of cutpoint candidates based upon the signatures produced by the random simulation. Cutpoint candidates within each class are resolved to determine whether the candidates are equivalent. If the nets are likely to be equivalent, BDD composition is performed on the nets. Otherwise, SAT-based analysis is performed on the nets. If either method fails to resolve the cutpoints within an allocated amount of time or resources, then the other method is invoked and information learned by the first method is passed to the second method to assist in the resolution. This process repeats until the cutpoint candidates are resolved. If the cutpoint resolution produces a true negative, then the candidate classes are refined by performing directed simulation on the inputs of the netlists using the witness to the true negative generated by the cutpoint resolution. This directed simulation produces new candidate classes that are resolv…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.