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:
Apr. 28, 2009
Filed:
Feb. 15, 2007
Shu-wei Chang, Sinjhuang, TW;
Wei Hwang, La Verne, CA (US);
Ming-hung Chang, Hsinchu, TW;
Po-tsang Huang, Yingge Township, Taipei County, TW;
Shu-Wei Chang, Sinjhuang, TW;
Wei Hwang, La Verne, CA (US);
Ming-Hung Chang, Hsinchu, TW;
Po-Tsang Huang, Yingge Township, Taipei County, TW;
National Chiao Tung University, Hsinchu, TW;
Abstract
In the proposed stored don't-care hierarchical search-line scheme, a content-addressable memory (CAM) is divided into several blocks. Each block contains a plurality of local search-lines, a global search-line, a buffer and a memory memory cell. Data are stored in the blocks in order according to the length of the prefix. Data with the longest prefix is stored at the bottommost, and its don't-care state is used as the control signal of the buffer to control whether to transfer the data on the global search-line to the local search-line or not. The local search-line then transfer the value into the memory cell. There is no complex control circuit and extra storage device needed. Moreover, because the control signal directly comes from the don't-care state, power consumption on search-lines can be effectively reduced with no increase of search delay.