Patent ID: 7877569
Filing Date: 2011-01-25
Classification: G06F

Abstract:
1. A nonvolatile storage device to/from which data is written/read based on a logical address designated by a host, said nonvolatile storage device comprising: a nonvolatile memory to/from which data is written and read based on a physical address, said nonvolatile memory including a plurality of physical blocks; a logical/physical conversion table that stores relation information between the logical address and the physical address by indentifying a relationship between (i) a logical group address, which is an address of a logical group including a plurality of logical blocks, and (ii) an address of a physical group including at least one physical block, of the plurality of physical blocks comprising a data management unit of a plurality of data management units; a duplication table that stores duplication information identifying a relationship between the physical address and the logical address of (i) data having a size that is smaller than a size of the data management unit, and (ii) data for which the logical group address is identified in the relation information stored in said logical/physical conversion table; and a controller that controls an operation of said nonvolatile storage device, wherein said controller allows data, which has a logical address that is the same as a logical address of data already written in one of the plurality of management units, to be redundantly written in another management unit of the plurality of management units, wherein said controller controls the operation of said nonvolatile storage device using a plurality of write modes for redundantly writing the data having the logical address that is the same as the logical address of the data already written in the one of the plurality of management units, wherein said controller selectively switches between the plurality of write modes according to the logical address designated by the host, without updating the relation information stored in the logical/physical conversion table, and wherein the plurality of write modes includes at least two of: