Memory system and control method thereof
AssigneeKioxia Corporation
InventorsKazuya Kitsunai, Shinichi Kanno, Hirokuni Yano, Toshikatsu Hida, Junji Yano
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Abstract
A memory system includes a nonvolatile memory including a plurality of blocks as data erase units, a measuring unit which measures an erase time at which data of each block is erased, and a block controller which writes data supplied from at least an exterior into a first block which is set in a free state and whose erase time is oldest.
Claims20
A method of controlling a nonvolatile memory in a memory system, the nonvolatile memory including a plurality of blocks, each of the plurality of blocks being a unit for an erase operation, said method comprising:
- copying first data from a first block to a second block, the number of erase operations performed on the second block being larger than the number of erase operations performed on the first block;
- and
- when the copying is not performed, writing second data to a third block, the second data being data that is received through an interface and has not been stored in the nonvolatile memory.
A method of controlling a nonvolatile memory in a memory system, the nonvolatile memory including a plurality of blocks, each of the plurality of blocks being a unit for an erase operation, said method comprising:
- determining a difference between the number of erase operations performed on a first block and the number of erase operations performed on a second block, and
- upon determining that the difference is larger than a first threshold, copying first data from a third block to a fourth block, the number of erase operations performed on the fourth block being larger than the number of erase operations performed on the third block.
A method of controlling a nonvolatile memory in a memory system, the nonvolatile memory including a plurality of blocks, each of the plurality of blocks being a unit for an erase operation, the plurality of blocks including a plurality of first blocks, no valid data being stored in each of the plurality of first blocks, the valid data being data which is stored in a block and of which a logical address designated by a host is managed in the memory system to be associated with an identifier of the block, said method comprising:
- selecting a second block from the plurality of first blocks, the number of erase operations performed on the second block being smallest among the numbers of erase operations performed on the plurality of first blocks;
- and
- writing first data to the selected second block, the first data being data that is received through an interface and has not been stored in the nonvolatile memory.
Dependencies are inferred from the claim text.