Segmented match line arrangement for content addressable memory
US6452822B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 2001 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | Apr 26, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C15/04
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A semiconductor content addressable memory (CAM) is described that has the enhanced capability of simultaneously performing content search operations between two sets of input data and stored data. This invention utilizes a segmented ML scheme, where one long ML is separated into two parts: a SML (Segmented ML) and a main ML. The SML is for evaluation of the comparison between input A and the content stored in an array of CAM cells A, and the main ML is for evaluation of the comparison between input B and the content stored in an array of CAM cells B. A specialized circuit that ties the SML and the main ML together is provided. The SML sense & restore is utilized to sense the value on the SML, send the result to the main ML if the enable signal (enable SML) is on, and restore the SML to a precharge state, if necessary, after SML evaluation. The circuit is able to discharge the ML if the SML shows a mismatch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.