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:
Jan. 29, 2002
Filed:
Feb. 13, 2001
Subramani Kengeri, San Jose, CA (US);
Steve Lim, Cupertino, CA (US);
Silicon Access Networks, Inc., San Jose, CA (US);
Abstract
A content addressable memory (CAM) with built-in power saving management. The CAM includes a comparator circuit region that is coupled to a match line (ML) as well as a swing line (SL). The comparator circuit region is coupled to CAM cells. The comparator region is adapted for comparing match data with stored data within the CAM cells. The ML has its ML voltage level pre-charged to a pre-charge voltage level (Vc). Additionally, the SL is pre-charged to ground. In turn, in response to a data mismatch detected by the comparator, the ML voltage level drops from Vc by a ML voltage swing (Vswing) while the SL charge shares with the Ml. Advantageously, in response to this data mismatch, the SL charge shares with the ML such that Vswing is approximately less or equal to Vc/2. That is, the charge sharing prevents the ML from discharging all the way to ground. Thus, because Vswing is as large as Vc in a conventional CAM whereas Vswing is as large as about Vc/2 in the invention, the invention's Vswing restriction provides significant more power saving.