Background threshold voltage shifting using base and delta threshold voltage shift values in flash memory
US9251909B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2014 |
| Grant date | Feb 2, 2016 |
| Priority date | — |
| Expiry date | Sep 29, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2029/0409
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In one embodiment, a method for managing threshold voltage shifts in Flash memory includes determining, by a processor after writing data to a Flash memory block, base threshold voltage shift (TVSBASE) value(s) configured to track permanent changes in underlying threshold voltage distributions due to cycling of the Flash memory block, determining, after the writing of data to the Flash memory block, delta threshold voltage shift (TVSΔ) value(s) configured to track temporary changes, with respect to changes in the underlying threshold voltage distributions due to retention and/or read disturb errors, calculating an overall threshold voltage shift (TVS) value for the data written to the Flash memory block, the overall TVS value being a function of the TVSBASE and TVSΔ value(s) to be used when writing data to the Flash memory block, and applying the overall TVS value to a read operation of the data stored to the Flash memory block.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.