CAM NAND with OR function and full chip search capability
US8780634B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 2013 |
| Grant date | Jul 15, 2014 |
| Priority date | — |
| Expiry date | Aug 1, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/0483
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Various techniques for extending the capabilities of CAM NAND type memories are discussed. Multi-block or even full chip search operations can be performed. In addition to the inherent AND property of NAND strings, the memory array has an inherent OR property between NAND string from different blocks along the same bit line that can be exploited through multi-block CAM-type operations. To reduce data-dependent word line to word line effects, in multiple data dependent sensing operations, the sensing can be broken up into sub-operations that avoid data dependent values on adjacent word lines. To improve data protection, subsequent to writing a memory block with indices, the word lines are read back and compared bit-by-bit with their intended values and the results are accumulated to determine whether any of indices include error. A bloom filter can also be used as an initial check during data search operations in order to provide increased data protection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.