Quaternary content-addressable memory
US7523251B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 2005 |
| Grant date | Apr 21, 2009 |
| Priority date | — |
| Expiry date | Dec 30, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C11/56
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A quaternary content-addressable memory includes multiple entries configured to match a lookup word, with each of these entries including multiple cells and with the lookup word including multiple lookup bits for matching corresponding cells of each of the entries. Each of the cells is individually configurable to be in one of multiple states identified by two bits, with these states including a first matching state for matching a value of a corresponding bit of the lookup word with the value having a first matching value, a second matching state for matching the value of the corresponding bit having a second matching value, a wildcard state for matching the value of the corresponding bit having either the first or the second matching value, and an ignore state for indicating to ignore the cell in determining whether or not the entry to which the cell belongs matches the lookup word.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.