摘要:
As a semiconductor storage device that can efficiently perform a refresh operation, provided is a semiconductor storage device comprising a non-volatile semiconductor memory storing data in blocks, the block being a unit of data erasing, and a controlling unit monitoring an error count of data stored in a monitored block selected from the blocks and refreshing data in the monitored block in which the error count is equal to or larger than a threshold value.
摘要:
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.
摘要:
As a semiconductor storage device that can efficiently perform a refresh operation, provided is a semiconductor storage device comprising a non-volatile semiconductor memory storing data in blocks, the block being a unit of data erasing, and a controlling unit monitoring an error count of data stored in a monitored block selected from the blocks and refreshing data in the monitored block in which the error count is equal to or larger than a threshold value.
摘要:
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.
摘要:
A semiconductor storage device includes a first memory area configured in a volatile semiconductor memory, second, third and fourth memory areas configured in a nonvolatile semiconductor memory, and a controller which executes following processing. The controller executes a first processing for storing a plurality of data by the first unit in the first memory area, a second processing for storing data by a first management unit in the fourth memory area, a third processing for storing data by a second management unit in the third memory area, a fourth processing for moving an area of the third unit from the fourth memory area to the second memory area, a fifth processing for copying data to an area of the third unit and allocating the area to the second memory area, and a sixth processing for copying data to an empty area of the third unit in the second memory area.
摘要:
A method of controlling a nonvolatile semiconductor memory including a plurality of blocks, each one of the plurality of blocks being a unit of data erasing, includes determining a monitored block as a candidate for refresh operation from among the plurality of blocks based on a predetermined condition. The method includes monitoring an error count of data stored in the monitored block and not monitoring an error count of data stored in blocks excluding the monitored block among the plurality of blocks. The method also includes performing the refresh operation on data stored in the monitored block in which the error count is larger than a first threshold value.
摘要:
A semiconductor storage device includes a first memory area configured in a volatile semiconductor memory, second, third and fourth memory areas configured in a nonvolatile semiconductor memory, and a controller which executes following processing. The controller executes a first processing for storing a plurality of data by the first unit in the first memory area, a second processing for storing data by a first management unit in the fourth memory area, a third processing for storing data by a second management unit in the third memory area, a fourth processing for moving an area of the third unit from the fourth memory area to the second memory area, a fifth processing for copying data to an area of the third unit and allocating the area to the second memory area, and a sixth processing for copying data to an empty area of the third unit in the second memory area.
摘要:
A semiconductor storage device includes a first storage unit having a plurality of first blocks as data write regions; an instructing unit that issues a write instruction of writing data into the first blocks; a converting unit that converts an external address of input data to a memory position in the first block with reference to a conversion table in which external addresses of the data are associated with the memory positions of the data in the first blocks; and a judging unit that judges whether any of the first blocks store valid data associated with the external address based on the memory positions of the input data, wherein the instructing unit issues the write instruction of writing the data into the first block in which the valid data is not stored, when any of the first blocks does not store the valid data.
摘要:
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.
摘要:
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.