Abstract: According to one embodiment, a controller transmits a response to a write request to a host before executing matching between first management information and second management information.

Abstract: According to one embodiment, a memory controller includes a writing destination management unit which determines a writing destination of user data, an encoding unit which generates a parity of the user data, and an ECC management unit which measures a fatigue degree of each certain memory area of a nonvolatile memory, selects an encoding method to instruct the encoding unit to be performed according to the encoding method, and changes the encoding method to an encoding method having a high error correction capability in a case where the fatigue degree corresponding to the writing destination is equal to or higher than a threshold and a total sum of parities is equal to or less than a predetermined amount.

Abstract: According to one embodiment, a controller of a host causes a memory device to transit from a first state that is an active state to a second state that is a sleep state in a case where there is no access to the memory device for a first time or more. The controller causes the memory device to transit from the second state to the first state in a case where there is no access to the memory device for a second time or more after the transition to the second state.

Abstract: According to one embodiment, a memory controller includes a writing destination management unit which determines a writing destination of user data, an encoding unit which generates a parity of the user data, and an ECC management unit which measures a fatigue degree of each certain memory area of a nonvolatile memory, selects an encoding method to instruct the encoding unit to be performed according to the encoding method, and changes the encoding method to an encoding method having a high error correction capability in a case where the fatigue degree corresponding to the writing destination is equal to or higher than a threshold and a total sum of parities is equal to or less than a predetermined amount.

Abstract: A memory system includes a memory and a controller. The memory includes a first memory chip and a second memory chip. The controller controls the memory. Each of the first and second memory chips includes string units and blocks including the string units. The memory holds information indicating a partial bad block including a bad string unit, and indicating which one of string units is the bad string unit in the partial bad block.

Abstract: According to one embodiment, a nonvolatile memory system includes a memory including a first memory and a second memory, the first memory including memory strings, the memory strings including memory cell transistors connected in series; and a memory controller which compresses a failure string position information of the first memory, which stores the compressed failure string position information in the second memory, and which decompresses the compressed failure string position information stored in the second memory.

Abstract: A memory system according to an embodiment includes: a plurality of magnetic nanowires; a read unit configured to read data from the magnetic nanowires; a shift control unit configured to shift domain walls in the magnetic nanowires; and a read control unit configured to cause the read unit to read the data from the magnetic nanowires in parallel, store two or more of the data read in parallel, determine a misalignment in the data when the data corresponding to a first magnetic nanowire of the magnetic nanowires are delayed or advanced as compared to the data corresponding to a second magnetic nanowire of the magnetic nanowires, and correct the stored data based on the determined misalignment.

Abstract: According to one embodiment, when shifting to a sleep mode, a processor of a memory device transmits a first command and saving data to a host and issues a power shut-off request. The first command is a command for writing data to a first memory of the host. The saving data includes register information. The register information includes register data stored in the control register and an address of the control register. A power supply circuit shuts off power supply to a second memory of the memory device, the control register, the processor, and a peripheral circuit in response to the issued power shut-off request.

Abstract: According to one embodiment, a memory system includes a non-volatile memory, a resource managing unit that reclaims resources associated with the non-volatile memory and increases the resources, when the usage of the resources associated with the non-volatile memory reaches the predetermined amount, a transmission rate setting unit that calculates a setting value of the transmission rate to receive the write data from a host device, and a transmission control unit that receives the write data from the host device and transmits the received write data to the non-volatile memory. The transmission rate setting unit calculates a small setting value when the usage of the resources associated with the non-volatile memory increases. The transmission control unit executes the reception of the write data from the host device at the transmission rate of the setting value, while the resource managing unit reclaims the resources.

Abstract: According to one embodiment, a memory system includes a bit-error-rate manager configured to manage information associated with a bit error rate for each physical block, a logical-block constructing unit configured to construct a logical block based on the information associated with the bit error rate, and a block manager configured to manage the correspondence between the logical block constructed by the logical-block constructing unit and the physical blocks. The logical block is a collection of a plurality of physical blocks.

Abstract: According to an embodiment, The control method includes reading a plurality of first pages in parallel on the basis of respectively different operation parameters. each of the first pages is respectively included in a plurality of first blocks. Each of the operation parameters includes a read voltage. The control method includes performing error correction on each of read data, and selecting one operation parameter out of the plurality of different operation parameters based on a result of the error correction.

Abstract: According to an embodiment, a storage device includes: a non-volatile memory, encoding units configured to generate a first, second, and third error correction code word, respectively; a memory interface configured to store a first, second, and third error correction code words to the non-volatile memory, and read the first, second, and third error correction code words from the non-volatile memory; decoding units configured to decode the first, second, and third error correction code words, respectively; and a position estimating unit configured to estimate a position of an error in the second correction code word based on information indicating whether the third error correction code word has successfully been decoded and information indicating whether the first error correction code word has successfully been decoded. The decoding unit decodes the second error correction code word using the position of the error estimated with the position estimating unit.

Abstract: According to one embodiment, a virtual block is constructed according to configuration conditions that, when a plurality of physical blocks included in the virtual block are selected, the sum of the number of physical block pairs and the number of single blocks allocated from the same memory chip to one virtual block is less than or equal to a first value.

Abstract: According to one embodiment, a controller groups a plurality of memory cells in each of the pages into a plurality of groups. The plurality of groups includes a first group and a second group. In a case of reading data from a first page, The controller performs first reading. The first reading includes reading data from the first page by using a first operation parameter for the first group. The controller performs second reading. The second reading includes reading data from the first page by using a second operation parameter for the second group. The controller merges first read data and second read data, and return the merged data as read data read from the first page. The first read data is acquired by the first reading. The second read data is acquired by the second reading.

Abstract: According to one embodiment, a memory system is provided with a nonvolatile memory, a controller, a volatile memory and an address translation table. The address translation table includes a high level and a plurality of low levels. The high level indicates positions in the nonvolatile memory in which the low levels are recorded. The low levels indicate positions in the nonvolatile memory in which data is recorded. The controller holds the high level of the address translation table in the first area of the volatile memory, and shuts off the supply of power to the second area of the volatile memory based on a transition from a normal-power state to a low-power state.

Abstract: According to one embodiment, a memory controller controlling a NAND memory having D bits/cell, includes: a code encoder which generates a code word having correction capability of t symbols; a write control unit which controls writing of the code word to the NAND memory; and a code decoder which decodes the code word read from the NAND memory, wherein the write control unit dispersedly allocates 2×D pages stored in adjacent two word lines in a block of the NAND memory to 2×D/t or more code words.

Abstract: A memory system includes a memory device, and a controller which controls the memory device. The memory device includes a plurality of memory cells capable of rewriting data, a plurality of word lines connected to the plurality of memory cells, a page including the plurality of memory cells connected to the same word line, a plane including a plurality of pages, a memory cell array including a plurality of planes, and a plurality of word line drivers which apply voltages to the plurality of word lines, and a plurality of switches provided for each plane and which assigns the word line drivers to the word lines.

Abstract: According to an embodiment, a retention time of each block group is managed and a degree of wear of each block is managed. A free block allocated to each block group is determined based on the retention time of each block group and the degree of wear of each block.

Abstract: According to one embodiment, a memory system includes a nonvolatile memory including first blocks configured to store an address indicating a data storage position, and second blocks configured to store the data, a first table configured to store a first address including first information and second information, the second information indicating a data storage position in the first block, and a second table configured to convert the first information into third information, the first information having a first data size by which one entry of the second table can be identified, the third information having a second data size which is larger than the first data size and by which one of the first blocks and the second blocks can be identified.

Abstract: According to one embodiment, a memory system includes a first memory, an interface, and a control unit. The first memory can operate in first mode in which n (n?2) pieces of unit data are written per word line and in second mode in which one piece of unit data is written per word line. When n pieces of unit data to be written to the first word line exist in the second memory, the control unit writes the first unit data to the first word line, using the n pieces of unit data to be written to the first word line. When receiving a flush request, the control unit writes a second unit data to a second word line, the second unit data being unit data stored in the second memory, based on the second mode.