Deterministic read retry method for soft LDPC decoding in flash memories
US10176041B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 2014 |
| Grant date | Jan 8, 2019 |
| Priority date | — |
| Expiry date | Oct 25, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/6325
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method is disclosed for performing LDPC soft decoding of data stored in a flash storage device. Upon occurrence of a hard read failure, one or more retries with soft decoding after each retry are performed until soft decoding is successful or a maximum iteration count is reached. For each retry thresholds for sensing a level of a cell are adjusted according to a specific sequence. Likewise, the LLR table for each retry is selected from pre-determined LLR tables each corresponding to a retry attempt and the thresholds used for the retry attempt. The LLR table is not adjusted between retries or based on outcomes of any retries. A step size by which thresholds adjusted may be tuned to improve performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.