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:
Sep. 20, 2005
Filed:
Nov. 04, 2002
Zhaoxuan Shen, San Jose, CA (US);
Zhaoxuan Shen, San Jose, CA (US);
Cadence Design Systems, Inc., San Jose, CA (US);
Abstract
A method for use by a placement and routing tool automatically selects positions for all n I/O buffers of an IC from among a set of m available legal positions for such buffers within an IC layout so as to best meet a set of criteria affected by I/O buffer placement. The method initially establishes a weighted cost function cquantifying a cost, relative to that set of criteria, of assigning the iI/O buffer to the jlegal position. The weighted cost function is then evaluated with respect to each possible combination of i and j to produce an m×n cost data matrix indicating all costs associated with all of the m×n possible I/O buffer placements. The cost data matrix is then analyzed to produce a placement plan assigning each I/O buffer to a separate legal position in a way that minimizes a total cost of the buffer placement with respect to the set of criteria. The method may also be used to assign I/O pads among a set of legal pad positions.