Abstract: According to one embodiment, a memory system encodes a plurality of data frames written in the same block in an inter-frame direction and generates first parity data, encodes the first parity data in the inter-frame direction and generates second parity data, generates a plurality of pieces of first frame data by concatenating at least a part of the first or second parity data with each of the plurality of data frames, encodes each of the plurality of pieces of first frame data in an intra-frame direction and generates a plurality of third parity data, and writes a plurality of pieces of second frame data obtained by concatenating each of the plurality of pieces of first frame data and each of the plurality of pieces of third parity data in a plurality of pages in the same block in the non-volatile memory one by one.

Abstract: According to one embodiment, a memory system includes a memory and a controller electrically connected to the memory. The memory includes blocks. Each of the blocks includes one or more sub-blocks. Each of the one or more sub-blocks includes nonvolatile memory cells. The controller is configured to obtain read frequency of at least one of the sub-blocks, and move data stored in the at least one of the sub-blocks so that data having substantially the same read frequency are written into one block.

Abstract: According to one embodiment, a memory system comprising includes a semiconductor memory and a memory controller. The memory controller is configured to obtain first data read from the semiconductor memory using a first voltage, obtain second data read from the semiconductor memory using a second voltage, calculate a first value for a first section of the first data using the first data and the second data, calculate a second value for a second section of the first data using the first data and the second data, calculate a third value for a third section of the first data using the first data and the second data, and correct an error of the first data using the first to third values.

Abstract: According to one embodiment, a nonvolatile memory includes a plurality of memory areas and controller circuit including an error correction code encoder. The error correction code encoder encodes a first data to generate a first parity in a first operation and encodes a second data to generate a second parity in a second operation. The controller circuit writes the first data and the first parity into a first memory area among the plurality of memory areas and writes the second data and the second parity into a second memory area among the plurality of memory areas. The size of the second data is smaller than the size of the first data and the size of the second parity is equal to the size of the first parity.

Abstract: A semiconductor storage device includes a first memory area configured in a volatile semiconductor memory, second and third 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 outputted from the first memory area by a first management unit in the second memory area, and a third processing for storing data outputted from the first memory area by a second management unit in the third memory area.

Abstract: A semiconductor storage device includes a first memory area configured in a volatile semiconductor memory, second and third 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 outputted from the first memory area by a first management unit in the second memory area, and a third processing for storing data outputted from the first memory area by a second management unit in the third memory area.

Abstract: According to one embodiment, a memory system includes a nonvolatile semiconductor memory, and a controller. The semiconductor memory includes a memory cell, and a write circuit configured to write data to the memory cell by applying a program voltage to the memory cell and comparing a threshold voltage of the memory cell with a first reference voltage corresponding to the write data. The write circuit is configured to execute a first programming operation to obtain a value of a write parameter by comparing the threshold voltage with a second reference voltage different from the first reference voltage.

Abstract: According to one embodiment, a memory system includes a nonvolatile memory and a controller electrically connected to the nonvolatile memory. The controller selects a write mode from a first mode in which data having N bits is written per one memory cell and a second mode in which data having M bits is written per one memory cell. N is equal to or larger than one. M is larger than N. The controller writes data into the nonvolatile memory in the selected write mode. The controller selects either the first mode or the second mode at least based on a total number of logical addresses mapped in a physical address space of the nonvolatile memory.

Abstract: A memory system includes a nonvolatile memory and a memory controller. The memory controller is configured to execute a process to adjust a temperature of the nonvolatile memory upon determining that the temperature is outside a preferred range.

Abstract: According to one embodiment, a memory system includes a first memory as a nonvolatile memory storing first data, second data as a translation table for accessing the first data, third data, fourth data as a translation table for accessing the third data, and including two memory cell arrays which are accessible in parallel, a second memory in which the second and fourth data is storable, and which stores a management table for managing information about whether the second and fourth data is stored in the second memory, a controller checking whether the second and fourth data is stored in the second memory based on the management table, a third memory storing an order of executing commands to be issued to the first memory, and a scheduler scheduling the order based on a result of the checking, two of a first command for reading the first data, a second command for reading the second data, a third command for reading the third data and a fourth command for reading the fourth data being executed in parallel in t

Abstract: A memory system includes a nonvolatile memory that has a plurality of physical blocks, and a memory controller circuit configured to execute encoding of data to be written in the nonvolatile memory and decoding of data read from the nonvolatile memory, execute garbage collection for the nonvolatile memory, and determine whether or not decoding and encoding is to be executed, for data which is read from a valid cluster of a physical block targeted for garbage collection.

Abstract: According to one embodiment, a memory system includes a semiconductor memory and a controller. The semiconductor memory includes blocks each containing memory cells. The controller is configured to instruct the semiconductor memory to execute a first operation and a second operation. In the first operation and the second operation, the semiconductor memory selects at least one of the blocks, and applies at least one voltage to all memory cells contained in said selected blocks. A number of blocks to which said voltage is applied per unit time in the second operation is larger than that in the first operation.

Abstract: According to one embodiment, a memory system includes a nonvolatile first memory, a second memory which has a buffer, and a memory controller. The memory controller manages a plurality of pieces of translation information. In a case where the plurality of pieces of translation information include a first plurality of pieces of translation information, the memory controller caches first translation information among the first plurality of pieces of translation information and does not cache second translation information among the first plurality of pieces of translation information. The first plurality of pieces of translation information linearly correlates a plurality of continuous physical addresses with a plurality of continuous logical addresses.

Abstract: According to one embodiment, a memory system includes a nonvolatile memory and a controller. The nonvolatile memory includes erase blocks. The controller is configured to provide a host device with first information. The first information is indicative of whether or not an erase block to which data associated with a first stream are written and data unassociated with the first stream are not written is used for a garbage collection operation of the nonvolatile memory.

Abstract: According to one embodiment, a memory system includes a first memory as a nonvolatile memory storing first data, second data as a translation table for accessing the first data, third data, fourth data as a translation table for accessing the third data, and including two memory cell arrays which are accessible in parallel, a second memory in which the second and fourth data is storable, and which stores a management table for managing information about whether the second and fourth data is stored in the second memory, a controller checking whether the second and fourth data is stored in the second memory based on the management table, a third memory storing an order of executing commands to be issued to the first memory, and a scheduler scheduling the order based on a result of the checking, two of a first command for reading the first data, a second command for reading the second data, a third command for reading the third data and a fourth command for reading the fourth data being executed in parallel in t

Abstract: According to one embodiment, a controller executes first refreshing in a case where a first value of a first block is larger than a first threshold and less than a second threshold. The first refreshing includes reprogramming a plurality of second memory cells among a plurality of first memory cells included in the first block.

Abstract: A memory system includes a non-volatile memory having a plurality of memory cells, and a controller configured to carry out write operations in a first mode in which n-bit data is written per target memory cell of the non-volatile memory until an allowable data amount of data items has been written, and then, in a second mode in which m-bit data is written per target memory cell of the non-volatile memory, where n is an integer of one or more and m is an integer greater than n. The controller is further configured to detect that an idle state, in which a command has not been received from the host, has continued for a threshold period of time or more, increase the allowable data amount in response thereto, and after the increase, carry out a write operation to write data items in the non-volatile memory in the first mode.

Abstract: According to one embodiment, a controller executes first refreshing in a case where a first value of a first block is larger than a first threshold and less than a second threshold. The first refreshing includes reprogramming a plurality of second memory cells among a plurality of first memory cells included in the first block.

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.

Abstract: According to one embodiment, a memory system includes a nonvolatile first memory, a second memory which has a buffer, and a memory controller. The memory controller manages a plurality of pieces of translation information. In a case where the plurality of pieces of translation information include a first plurality of pieces of translation information, the memory controller caches first translation information among the first plurality of pieces of translation information and does not cache second translation information among the first plurality of pieces of translation information. The first plurality of pieces of translation information linearly correlates a plurality of continuous physical addresses with a plurality of continuous logical addresses.