Selective match line discharging in a partitioned content addressable memory array
US6191970A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 13, 2000 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | May 13, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C15/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Rows of a CAM array are partitioned into a plurality of row segments, with each row segment having a number of CAM cells coupled to a corresponding match line segment. Each CAM cell includes a discharge circuit connected between the cell and ground potential. The discharge circuits connected to CAM cells in a row segment each include a control terminal coupled to receive a control signal indicative of the logical state of the match line segment of the preceding row segment. During compare operations, all match line segments are pre-charged toward a supply voltage. If there is a match in a first row segment, the first match line segment remains charged and, in response thereto, the discharge circuits within a subsequent row segment are turned on to allow the subsequent match line segments to indicate match conditions in the subsequent row segment. On the other hand, if there is a mismatch condition in the first row segment, thereby discharging the first match line segment, the discharge circuits in the subsequent row segment turn off to prevent corresponding match line segments in subsequent row segments from discharging.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.