System and method for performing data retention in solid-state memory utilizing copy commands and usage data
US9135166B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 2013 |
| Grant date | Sep 15, 2015 |
| Priority date | — |
| Expiry date | Nov 22, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/7209
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Systems and methods for retaining data in non-volatile solid-state memory are disclosed in which refresh copy operations are performed on data stored in non-volatile solid-state memory. A controller can comprise a data retention module configured to issue copy commands within different periods of time and to maintain usage data on a storage subsystem. A refresh copy operation helps ensure that data written to memory retain integrity by causing data to be programmed again onto the memory. Execution of refresh copy commands may be prioritized over other commands based on a remaining length of time. One or more data structures may be used to determine memory blocks that require refresh copy operations. In one embodiment, a validity bit array is used to track blocks that contain valid data. In another embodiment, a least recently used list is used to track blocks that have been least recently written.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.