Memory system managing access to nonvolatile memory
AssigneeToshiba Memory Corporation
InventorKohei Oikawa
Life of this patent
Estimating the term…
Abstract
According to one embodiment, for each area having a first size, a number of accesses to the area is recorded in first information. In units of sub areas each having a second size smaller than the first size, access information for the sub area is recorded in the second information. In the first information, the number of accesses to an area to which a sub area in which duplicate accesses occur belongs is updated.
Claims19
A memory system comprising:
- a nonvolatile memory including a plurality of areas having a first size and respective sub areas of a second size;
- a first recording unit;
- a second recording unit;
- and
- a memory controller configured to
- record, for each area, a number of accesses to the area in the first recording unit,
- record, in units of sub areas, access information to the sub area in the second recording unit, each of the sub areas being included in one of the areas and having a second size smaller than the first size, and
- for each of the areas for which accesses are recorded in the first recording unit and to which belongs a sub area in which occurs a duplicate access recorded in the second recording unit, update the number of accesses to each said area in the first recording unit in relation to the duplicate access to the respective sub area recorded in the second recording.
A memory system comprising:
- a nonvolatile memory including a plurality of areas having a first size, each area including respective sub areas of a second size smaller than said first size, and each sub area having small areas of a third size smaller than said second size;
- a first recording unit
- a second recording unit
- a third recording unit and
- a memory controller configured to
- control the nonvolatile memory,
- record, for each area, a number of accesses to the area in first recording unit,
- record, for each sub area, access information to the sub area in the second recording unit,
- record, in units of small areas, access information to the small areas in third recording unit,
- for each of the sub areas for which accesses are recorded in the second recording unit and to which belongs a small area in which occurs a duplicate access recorded in the third recording unit, update the number of accesses to each said sub area in the second recording unit in relation to the duplicate access to the respective small area recorded in the third recording unit, and
- for each of the areas for which accesses are recorded in the first recording unit and to which belongs the sub area in which occurs the duplicate access recorded in the second recording unit, update the number of accesses to each said area in the first recording unit in relation to the duplicate access to the respective sub area recorded in the second recording.
A method of controlling a memory system, the memory system including a nonvolatile memory including a plurality of areas having a first size and respective sub areas of a second size, a first recording unit, and a second recording unit, the method comprising:
- recording, for each area, a number of accesses to the area in first recording unit,
- recording, in units of sub areas, access information to the sub area in second recording unit,
- for each of the areas for which accesses are recorded in the first recording unit and to which belongs a sub area in which occurs a duplicate access recorded in the second recording unit, updating the number of accesses to each said area in the first recording unit in relation to the duplicate access to the respective sub area recorded in the second recording.
Dependencies are inferred from the claim text.