Content addressable memory storage device
US6044005A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1999 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Feb 3, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C15/046
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Binary and ternary content addressable memory (CAM) cells are disclosed, which permit the construction of high-performance, large-capacity CAM arrays. The CAM cells have a reduced match line power dissipation, and a reduced compare line loading that is data independent, and full swing comparator output. Match line power dissipation is limited by means of a NAND chain match line. Loading on compare lines is limited by connecting compare lines to the gate terminals of the CAM cell comparator. Local precharge devices at the output of the comparator provide full swing compare logic levels for faster matching. The same precharge devices also serve as an active reset for the comparator. Comparator circuits for ternary CAM cells further employ disable means, which makes the comparison operation conditional on the value stored in the mask memory element. The use of disable means allows the mask and data to be stored separately in a non-encoded form. As a result, mask and data information may be read and written independently of one another.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.