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:
May. 21, 2013
Filed:
Jul. 08, 2009
Nathan Francis Sheeley, Austin, TX (US);
Mark H. Nodine, Austin, TX (US);
Nicolas Xavier Pena, Austin, TX (US);
Irfan Waheed, Austin, TX (US);
Patrick Peters, Austin, TX (US);
Adrian J. Isles, Alameda, CA (US);
Nathan Francis Sheeley, Austin, TX (US);
Mark H. Nodine, Austin, TX (US);
Nicolas Xavier Pena, Austin, TX (US);
Irfan Waheed, Austin, TX (US);
Patrick Peters, Austin, TX (US);
Adrian J. Isles, Alameda, CA (US);
Apple Inc., Cupertino, CA (US);
Abstract
This disclosure describes a method for accomplishing sequential logical equivalence verification using a hierarchical piecewise approach. Initially, the method provides a reference semiconductor design and a second semiconductor design with logic edits relative to it. The method submits both to formal verification to check the reference design against the second semiconductor design with all edits disabled. The semiconductor design is partitionedand associated input constraints. The edits are further groupedand ordered. The invention also discovers a set of dependencies of the logic editsand checks that the ordering of groups obeys the dependencies. Each group of edits is further submitted to formal verificationand any input constraints assumed for any partitions are verified in their enclosing partition. Finally, the method reports success if formal verification succeeds on each group of logic edits and on each set of input constraints