Kabushiki Kaisha Toshiba

Takaya Suda

Hiroaki Muraoka

Daisaburo Takashima

Shuso Fujii

Takuya Futatsuyama

Hiroshi Sukegawa

Masaki Momodomi

Masayasu Kawase

According to one embodiment, a storage device includes a nonvolatile memory, a controller configured to copy data stored in a first page in a first block to a second page in a second block, and an ECC circuit. The controller reads data from a part of the first page by using an upper limit voltage and lower limit voltage, performs a direct copy operation in the nonvolatile memory without via the ECC circuit if the number of error cells having threshold voltages higher than the lower limit voltage and lower than or equal to the upper limit voltage is less than or equal to a specified value, and performs error correction by using the ECC circuit if the number of error cells exceeds the specified value.

Storage device and control method of nonvolatile memory

A memory system includes a nonvolatile memory having a plurality of data blocks each of which is a unit of data erase and has a plurality of pages, each of the pages being a unit of data write, and a controller which checks whether or not the nonvolatile memory has been affected by power interruption at power-on time and, if the nonvolatile memory has been affected by power interruption, writes data to that first page in a first data block which has not been affected by power interruption.

Memory system with nonvolatile memory

A memory system includes a nonvolatile semiconductor memory which includes a first original block composed of n (n being natural number) write unit areas and a first subblock composed of a plurality of write unit areas. A controller writes data having one of first to p-th (p being natural number smaller than n) addresses into the first original block. The controller writes data which has a first write address of one of the first to p-th addresses into the first subblock when the controller receives request to write data having the first write address and data having the first write address exists in the first original block.

Memory system and method of writing into nonvolatile semiconductor memory

A system for authenticating a memory card including: a memory card host device including a plural area authentication module which judges whether the memory card has plural storage areas, and an area switching module which switches a storage area subject to access a different storage area from among plural storage areas; a memory card including plural storage areas, at least one internal register which retains a value indicating the number of storage areas, and a controller which transmits the value indicating the number of the storage areas to the memory card host device; and a bus which transmits and receives data between the memory card host device and the memory card.

Memory card authentication system, memory card host device, memory card, storage area switching method, and storage area switching program

An apparatus for estimating a frequency of access to a storage device that includes a flash memory and a controller for controlling the flash memory includes interface. Data is written into the flash memory in units of a page and being erased from the flash memory in units of a block consisting of pages. The interface is supplied with an internal signal transferred between the flash memory and the controller, configured to recognize the internal signal, and outputs the internal signal as an input signal. An erasure sequence detection section outputs a detection signal when address data is followed by an erasure command requesting erasure of data in the block specified by the address data in the input signal. An address holding section holds address data in the internal signal, and outputs held address data as erasure address data when supplied with the detection signal.

Access frequency estimation apparatus and access frequency estimation method

A memory system includes a ferroelectric memory formed by arranging a plurality of memory cells having a ferroelectric capacitor and cell transistor, a flash EEPROM formed by arranging a plurality of memory cells having a floating gate and capable of electrically erasing and writing data, a control circuit configured to control the ferroelectric memory and flash EEPROM, and an interface circuit configured to communicate with the outside. The flash EEPROM stores data. The ferroelectric memory stores at least one of root information for storing the data, directory information, the file name of the data, the file size of the data, file allocation table information storing the storage location of the data, and the write completion time of the data.

Memory system combining flash EEPROM and FeRAM

A memory management device for managing a nonvolatile semiconductor memory which comprises a plurality of blocks, and permits data to be erased in units of one block, the memory management device comprises a setting unit configured to set an address range of data to be erased in response to an erase command in a block in which the data to be erased is written, when the erase command is issued with respect to the nonvolatile semiconductor memory and a controlling unit configured to output initial-value data as data to be read in response to a data read command, when the data read command is issued with respect to the nonvolatile semiconductor memory, and then when an address range of the data to be read in response to the data read command is included in the address range set by the setting unit.

Memory management device and memory device

A memory system includes a ferroelectric memory, flash EEPROM, control circuit, and interface circuit. The control circuit is configured to control the ferroelectric memory and flash EEPROM. The interface circuit is configured to communicate externally. Data is programmed in the flash EEPROM by a write unit which is smaller than a block as an erase unit and larger than a page as a program unit. The ferroelectric memory stores a logical address-physical address conversion table using the write unit.

Memory system having improved random write performance

A memory device used attach to a host system includes a nonvolatile memory including a plurality of blocks, each of the blocks being a unit for data erasure and including a plurality of pages, each of the pages including a data section which stores first data supplied from the host system, and a redundancy section which stores at least second data used to manage the first data, a detection circuit which generates a first code used to detect a first error contained in the second data, and detects the first error based on the first code, and a correction circuit which generates a second code used to detect and correct a second error contained in the first data and the second data, and detects and corrects the second error based on the second code.

Growing community of inventors

Kamakura, Japan

Takaya Suda