Memory system and control method thereof
US7949910B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 2010 |
| Grant date | May 24, 2011 |
| Priority date | — |
| Expiry date | Feb 12, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/16
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A memory system includes a nonvolatile memory including blocks as data erase units, a measuring unit which measures an erase time at which data in each block is erased, a block controller having a block table which associates a state value indicating one of a free state and a used state with the erase time for each block, a detector which detects blocks in which rewrite has collectively occurred within a short period, a first selector which selects a free block having an old erase time as a first block, a second selector which selects a block in use having an old erase time as a second block, and a leveling unit which moves data in the second block to the first block if the first block is included in the blocks detected by the detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.