Circuit and method for subdividing a CAMRAM bank by controlling a virtual ground
US7242600B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 2005 |
| Grant date | Jul 10, 2007 |
| Priority date | — |
| Expiry date | Oct 28, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C15/04
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A CAM bank is functionally divided into two or more sub-banks, without replicating CAM driver circuits, by disabling all match line discharge circuits in the bank, and selectively enabling the discharge circuits in entries comprising sub-banks. At least one selectively actuated switching circuit is interposed between the virtual ground node of each discharging comparator in the discharge circuit of a sub-bank and circuit ground. When the switching circuit is in a non-conductive state, the virtual ground node is maintained at a voltage level sufficiently above circuit ground to preclude discharging a connected match line within the CAM access time. When the switching circuit is placed in a conductive state, the virtual ground node is pulled to circuit ground and the connected match line may be discharged by a miscompare. Control signals, which may be decoded from address bits, are distributed to the switching circuits to define the CAM sub-banks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.