Threshold estimation in NAND flash devices
US11232842B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 2020 |
| Grant date | Jan 25, 2022 |
| Priority date | — |
| Expiry date | Nov 18, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C29/56008
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for determining an optimal threshold of a nonvolatile memory device, the method including: reading a page from a nonvolatile memory device with a default threshold and attempting to hard decode the page using the default threshold; reading the page two more times with a predetermined offset voltage when the hard decoding fails and attempting to soft decode the page using the default threshold; approximating an empirical distribution of successfully decoded bits with a Gaussian distribution for each level; finding an intersection of the Gaussian distributions; and setting the intersection as a new reading threshold and reading the page again with the new reading threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.