Toshiba Memory Corporation

Kioxia Corporation

Masahiro Kiyooka

Yoshihisa Kojima

Hironori Uchikawa

Kenji Sakurada

Daiki Watanabe

Naoaki Kokubun

Yuta Kumano

Kosuke Morinaga

Yoshiki Notani

Toshikatsu Hida

Riki Suzuki

A memory system according to an embodiment includes a nonvolatile memory and a memory controller. The nonvolatile memory includes a plurality of memory cells. The memory controller is configured to control the nonvolatile memory. In read operation for the memory cells, the memory controller is configured to: perform tracking including a plurality of reads in which a read voltage is shifted; determine a hard bit read voltage based on results of the tracking; calculate a soft bit read voltage based on the determined hard bit read voltage; perform soft bit read using the calculated soft bit read voltage; and perform a soft bit decoding process using a result of the soft bit read and a log-likelihood ratio table associated with the calculated soft bit read voltage.

Memory system

According to one embodiment, a memory system includes a non-volatile memory, a memory interface that reads data recorded in the non-volatile memory as a received value, a converting unit that converts the received value to first likelihood information by using a first conversion table, a decoder that decodes the first likelihood information, a control unit that outputs an estimated value with respect to the received value, which is a decoding result obtained by the decoding, when decoding by the decoder has succeeded, and a generating unit that generates a second conversion table based on a decoding result obtained by the decoding, when decoding of the first likelihood information by the decoder has failed. When the generating unit generates the second conversion table, the converting unit converts the received value to the second likelihood information by using the second conversion table, and the decoder decodes the second likelihood information.

Soft decoding method using LLR conversion table

Memory system and control method

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.

Memory system including a memory controller and error correction circuit for reading multi-bit data and for detecting and correcting read data errors

According to one embodiment, a storage device includes a plurality of nonvolatile semiconductor memories, a sensor and a controller. The sensor is configured to measure a temperature of the nonvolatile semiconductor memories. The controller is configured to receive data from a host, determine a rewriting interval of the data and write the data to, of the nonvolatile semiconductor memories, a nonvolatile semiconductor memory having a temperature corresponding to the rewriting interval.

Storage device and storage method

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Kanagawa, Japan

Masahiro Kiyooka