Auto-learning log likelihood ratio
US10291263B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 2017 |
| Grant date | May 14, 2019 |
| Priority date | — |
| Expiry date | Aug 1, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/0483
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for identifying log likelihood ratio (LLR) values includes programming codewords into nonvolatile memory devices in response to receiving host-requested write instructions and performing background reads of the programmed codewords in a block at a default threshold voltage, at one or more threshold voltage offset that is less than the default threshold voltage and at one or more threshold voltage offset that is greater than the default threshold voltage. One of the background reads is decoded to identify the stored codeword(s) and a set of LLR values is identified using the stored read results and the identified codeword(s). The process of performing background reads, storing, decoding and identifying is repeated to identify a set of LLR values for each block and further to identify updated sets of LLR values. Host-requested reads are performed and are decoded using LLR values from the updated set of LLR values corresponding to the block that was read.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.