The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 08, 2000
Filed:
Jun. 23, 1998
Ronald H Hardin, Pataskala, OH (US);
Robert Paul Kurshan, New York, NY (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
A method and apparatus for efficiently determining whether a set of constraints input to a verification tool are mutually contradictory or overconstraining. A set of constraints are mutually contradictory or overconstraining when they define values for system-model variables and/or inputs that are inconsistent with each other at a given state or group of states of a system-model state machine. It has been found that when a set of constraints assign inconsistent values at a given state or group of states of the system-model state space, the verification tool will treat the given state or group of states as a so-called non-returnable state. That is, the verification tool will not recognize any paths from the given state or group of states to a set of reset states. As a result, instead of having to analyze the values defined by every constraint input to the verification tool, it can be determined whether a set of constraints input to the verification tool are mutually contradictory or overconstraining by analyzing only the constraints enabled at the non-returnable states.