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. 04, 2012
Filed:
Apr. 25, 2011
Meng-kai Hsu, New Taipei, TW;
Yao-wen Chang, Taipei, TW;
Tung-chieh Chen, Taipei, TW;
Springsoft Inc., Hsinchu, TW;
Springsoft USA, Inc., San Jose, CA (US);
Abstract
A placer produces a global placement plan specifying positions of cell instances and orientations of macros within an integrated circuit (IC) by initially clusterizing cell instances and macros to form a pyramidal hierarchy of blocks. Then the placer iteratively repeats the declusterization and routability improvement process from the highest level to the lowest level of the hierarchy. An objective function is provided in Cartesian coordinate for representing the position of each movable instance and in polar coordinate for representing the orientation of a macro relative to its the center. For each movable instance and each rotatable macro, its position or orientation is determined by conjugate gradient method to minimize total wire length. Finally, the placer uses a look-ahead legalization technique to rotate rotatable macros to legal orientations and move cell instances to legal positions in the end of global placement.