Flash memory device with physical cell value deterioration accommodation and methods useful in conjunction therewith
US8321625B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 2008 |
| Grant date | Nov 27, 2012 |
| Priority date | — |
| Expiry date | Apr 17, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/1032
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for determining thresholds useful for converting cell physical levels into cell logical values in an array of digital memory cells storing physical levels which diminish over time, the method comprising determining extent of deterioration of the physical levels and determining thresholds accordingly for at least an individual cell in said array; and reading the individual cell including reading a physical level in the cell and converting the physical level into a logical value using the thresholds, wherein the determining comprises storing predefined physical levels rather than data-determined physical levels in each of a plurality of cells and computing extent of deterioration by determining deterioration of the predefined physical levels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.