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:
Nov. 24, 1998
Filed:
Mar. 12, 1996
Yang Cai, San Jose, CA (US);
Michael Chin-Hsen Lin, Fremont, CA (US);
Avant| Corporation, Fremont, CA (US);
Abstract
A method for optimal track assignment in a grid-based channel router. Initially, interconnection information is extracted from a global routing result. Multiple pin nets derived from the interconnection information are decomposed into simpler mapped segments. A channel grid map is then built and marked with existing objects. Next, a vertical constraint graph specifying the relative positions of the mapped segments is constructed. A first track is computed. A track assignment loop is repeated until all requisite connections are realized. The track assignment loop includes the steps of breaking cycles and long paths and collecting a set of feasible links. One or more weighting functions are assigned to each such feasible link. A dynamic programming approach is used to select an optimal set of feasible links according to the weighting functions. In addition, an optimal set of feasible links corresponding to unpreferred layers is collected by applying dynamic programming. Finally, the chosen feasible links are physically realized on the current track.