Soft decoding of hard and soft bits read from a flash memory
US7814401B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2006 |
| Grant date | Oct 12, 2010 |
| Priority date | — |
| Expiry date | Jul 1, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2211/5634
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
To read one or more flash memory cells, the threshold voltage of each cell is compared to at least one integral reference voltage and to at least one fractional reference voltage. Based on the comparisons, a respective estimated probability measure of each bit of an original bit pattern of each cell is calculated. This provides a plurality of estimated probability measures. Based at least in part on at least two of the estimated probability measures, respective original bit patterns of the cells are estimated. Preferably, the estimated probability measures are initial probability measures that are transformed to final probability measures under the constraint that the bit pattern(s) (collectively) is/are a member of a candidate set, e.g. a set of codewords.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.