Abstract: According to the embodiments, a first storage area and a second storage area specified by a trim request is managed by a first management unit, and the second storage area specified by the trim request is managed by a second management unit. A block in which data of the first management unit are all specified by the trim request from the first or second storage areas and a block in which data of the second management unit are all specified by the trim request from the second storage area are released.

Abstract: A controller performs a coding process based on a first frame including data of a plurality of pages connected to first word lines being a predetermined number of consecutive word lines in a block, and performs, when padding data is written to a plurality of pages connected to second word lines being the predetermined number of word lines subsequent to the first word lines, the coding process based on a second frame obtained by excluding the padding data from a frame including data of the pages connected to the second word lines.

Abstract: According to an embodiment, a controller performs a coding process based on a first frame including data of a plurality of pages connected to first word lines being a predetermined number of consecutive word lines in a block, and performs, when padding data is written to a plurality of pages connected to second word lines being the predetermined number of word lines subsequent to the first word lines, the coding process based on a second frame obtained by excluding the padding data from a frame including data of the pages connected to the second word lines.

Abstract: According to one embodiment, a controller reads out the non-volatile address management information required to execute one of the read commands into an address information cache and retrieves data from the nonvolatile memory according to the volatile address management information stored in the address information cache. In addition, the controller among the read commands stored in the command queue, preferentially executes the read command whose logical addresses are all found in the volatile address management information.

Abstract: According to the embodiments, a first storage area and a second storage area specified by a trim request is managed by a first management unit, and the second storage area specified by the trim request is managed by a second management unit. A block in which data of the first management unit are all specified by the trim request from the first or second storage areas and a block in which data of the second management unit are all specified by the trim request from the second storage area are released.

Abstract: According to one embodiment, a memory system comprises a nonvolatile memory including a memory cell array and a read buffer and a controller configured to receive a read request and to issue a first read command and a second read command to the memory. When issuing the first read command, the memory transfers data of the first size from the memory cell array to the read buffer and outputs the data from the read buffer to the controller. When issuing the second read command, the memory transfers first data of the first size from the memory cell array to the read buffer, outputs the first data from the read buffer to the controller, and transfers second data of the first size from the memory cell array to the read buffer. The controller selects one command from the two commands according to the read request.