Patents by Inventor Akira Yamaga

Akira Yamaga has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20170076801
    Abstract: A memory system includes a semiconductor memory device having memory cells arranged in rows and columns, and a controller configured to issue a write command with or without a partial page program command to the semiconductor memory device. The semiconductor memory device, in response to the write command issued without the partial page command, executes a first program operation on a page of memory cells and then a first verify operation on the memory cells of the page using a first verify voltage for all of the memory cells of the page, and in response to the write command issued with the partial page command, executes a second program operation on a subset of the memory cells of the page and then a second verify operation on the memory cells of the subset using one of several different second verify voltages corresponding to the subset.
    Type: Application
    Filed: June 6, 2016
    Publication date: March 16, 2017
    Inventors: Masanobu SHIRAKAWA, Kenta YASUFUKU, Akira YAMAGA
  • Patent number: 9264070
    Abstract: A memory controller includes a memory interface that has multiple channels and carries out writing into a nonvolatile memory through each of the channels, a data buffer, an ECC (error correcting code) encoder for applying an error correction encoding processing on write data which are to be written into the nonvolatile memory to generate ECC data, a channel allocation part for allocating the channels to the write data and the ECC data based on a write data format of the nonvolatile memory, a write data reception processing part that stores the write data in the data buffer and outputs the write data to the ECC encoder, and a channel scheduler for transferring the write data stored in the data buffer and the ECC data to the channels of the memory interface as allocated by the channel allocation part.
    Type: Grant
    Filed: November 26, 2012
    Date of Patent: February 16, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tatsuhiro Suzumura, Akira Yamaga
  • Patent number: 8879349
    Abstract: A storage device according to an embodiment includes first and second non-volatile semiconductor memories. In addition, the storage device includes first controller that controls the first non-volatile memory to cause the first non-volatile memory to perform processes. In addition, the storage device includes second controller that controls the second non-volatile memory to cause the second non-volatile memory to perform processes. The storage device further includes a signal line which is connected to the first controller and the second controller and through which a token is transmitted between the first controller and the second controller. The first controller is capable of controlling the first non-volatile memory while holding the token and the second controller is capable of controlling the second non-volatile memory while holding the token.
    Type: Grant
    Filed: August 6, 2013
    Date of Patent: November 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yoshii, Ikuo Magaki, Naoto Oshiyama, Tokumasa Hara, Akira Yamaga, Ryo Yamaki, Kenta Yasufuku, Naomi Takeda, Yu Nakanishi, Arata Miyamoto, Naoaki Kokubun, Daisuke Iwai
  • Publication number: 20140241096
    Abstract: A storage device according to an embodiment includes first and second non-volatile semiconductor memories. In addition, the storage device includes first controller that controls the first non-volatile memory to cause the first non-volatile memory to perform processes. In addition, the storage device includes second controller that controls the second non-volatile memory to cause the second non-volatile memory to perform processes. The storage device further includes a signal line which is connected to the first controller and the second controller and through which a token is transmitted between the first controller and the second controller. The first controller is capable of controlling the first non-volatile memory while holding the token and the second controller is capable of controlling the second non-volatile memory while holding the token.
    Type: Application
    Filed: August 6, 2013
    Publication date: August 28, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro YOSHII, Ikuo MAGAKI, Naoto OSHIYAMA, Tokumasa HARA, Akira YAMAGA, Ryo YAMAKI, Kenta YASUFUKU, Naomi TAKEDA, Yu NAKANISHI, Arata MIYAMOTO, Naoaki KOKUBUN, Daisuke IWAI
  • Patent number: 8812774
    Abstract: According to an embodiment, a memory system includes semiconductor memories each having a plurality of blocks; a first table; a receiving unit; a generating unit; a second table; and a writing unit. The first table includes a plurality of memory areas each associated with each block and in each of which defect information is stored. The generating unit generates a set of blocks by selecting one block to which data are to be written in each semiconductor memory based on an index number indicating one of a plurality of rows in the first table and the first table. In the second table, an index number and a channel number are stored for each logical block address in association with one another. When a write command is received by the receiving unit, the writing unit writes data to a block associated with a selected channel number among blocks constituting the set.
    Type: Grant
    Filed: August 25, 2011
    Date of Patent: August 19, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shigehiro Asano, Shinichi Kanno, Kazuhiro Fukutomi, Akira Yamaga
  • Patent number: 8751896
    Abstract: A semiconductor storage device, a method of controlling the same, and an error correction system allow reduction in power consumption and circuit scale without detriment to error correction capability. An error correction code (ECC) circuit of a solid state drive (SSD) performs first error correction on read data using a first error correction code (Hamming code), and further performs second error correction on the result of the first error correction using a second error correction code (BHC code). Furthermore, the ECC circuit performs third error correction on the result of the second error correction using a third error correction code (RS code).
    Type: Grant
    Filed: July 11, 2013
    Date of Patent: June 10, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Akira Yamaga
  • Publication number: 20140068378
    Abstract: According to an embodiment, a semiconductor storage device includes a memory, an encoding unit that generates a parity, and a decoding unit that includes a syndrome calculating unit, an error position polynomial calculating unit, and an error searching and correcting unit, and performs an error correcting process based on data and the parity read from the memory. At the time of performing a compaction process, a process of the error searching and correcting unit is not performed, when the number of error bits acquired by an error position polynomial is equal to or less than a first threshold value based on valid data.
    Type: Application
    Filed: February 21, 2013
    Publication date: March 6, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro YOSHII, Naoaki Kokubun, Naoto Oshiyama, Ryo Yamaki, Ikuo Magaki, Kenta Yasufuku, Akira Yamaga
  • Publication number: 20130297984
    Abstract: A semiconductor storage device, a method of controlling the same, and an error correction system allow reduction in power consumption and circuit scale without detriment to error correction capability. An error correction code (ECC) circuit of a solid state drive (SSD) performs first error correction on read data using a first error correction code (Hamming code), and further performs second error correction on the result of the first error correction using a second error correction code (BHC code). Furthermore, the ECC circuit performs third error correction on the result of the second error correction using a third error correction code (RS code).
    Type: Application
    Filed: July 11, 2013
    Publication date: November 7, 2013
    Inventor: Akira Yamaga
  • Patent number: 8499216
    Abstract: A semiconductor storage device, a method of controlling the same, and an error correction system allow reduction in power consumption and circuit scale without detriment to error correction capability. An error correction code (ECC) circuit of a solid state drive (SSD) performs first error correction on read data using a first error correction code (Hamming code), and further performs second error correction on the result of the first error correction using a second error correction code (BHC code). Furthermore, the ECC circuit performs third error correction on the result of the second error correction using a third error correction code (RS code).
    Type: Grant
    Filed: January 17, 2013
    Date of Patent: July 30, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Akira Yamaga
  • Publication number: 20130173997
    Abstract: A memory controller includes a memory interface that has multiple channels and carries out writing into a nonvolatile memory through each of the channels, a data buffer, an ECC (error correcting code) encoder for applying an error correction encoding processing on write data which are to be written into the nonvolatile memory to generate ECC data, a channel allocation part for allocating the channels to the write data and the ECC data based on a write data format of the nonvolatile memory, a write data reception processing part that stores the write data in the data buffer and outputs the write data to the ECC encoder, and a channel scheduler for transferring the write data stored in the data buffer and the ECC data to the channels of the memory interface as allocated by the channel allocation part.
    Type: Application
    Filed: November 26, 2012
    Publication date: July 4, 2013
    Inventors: Tatsuhiro SUZUMURA, Akira Yamaga
  • Patent number: 8418028
    Abstract: To provide a Chien search device and a Chien search method capable of performing a Chien search process at a high speed. The Chien search device calculates an error position at the time of correcting an error included in data read from a nonvolatile memory, and includes a first processing unit that performs a search process of an error position in at least one-bit unit to an error-correction area of input data, and a second processing unit that processes at one time plural bits in an non-error-correction-target area of the input data.
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: April 9, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Akira Yamaga
  • Patent number: 8381066
    Abstract: A semiconductor storage device, a method of controlling the same, and an error correction system allow reduction in power consumption and circuit scale without detriment to error correction capability. An error correction code (ECC) circuit of a solid state drive (SSD) performs first error correction on read data using a first error correction code (Hamming code), and further performs second error correction on the result of the first error correction using a second error correction code (BHC code). Furthermore, the ECC circuit performs third error correction on the result of the second error correction using a third error correction code (RS code).
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: February 19, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Akira Yamaga
  • Patent number: 8312348
    Abstract: An error correcting device for correcting erroneous data included in data read out from a nonvolatile memory includes a determining unit that determines whether the data read out from the nonvolatile memory include an error beyond an error correcting capability of the error correcting device. When the determining unit has determined that an error beyond the error correcting capability exists, the error correcting device does not perform the correction of the error.
    Type: Grant
    Filed: February 27, 2009
    Date of Patent: November 13, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Akira Yamaga
  • Publication number: 20120246383
    Abstract: According to an embodiment, a memory system includes semiconductor memories each having a plurality of blocks; a first table; a receiving unit; a generating unit; a second table; and a writing unit. The first table includes a plurality of memory areas each associated with each block and in each of which defect information is stored. The generating unit generates a set of blocks by selecting one block to which data are to be written in each semiconductor memory based on an index number indicating one of a plurality of rows in the first table and the first table. In the second table, an index number and a channel number are stored for each logical block address in association with one another. When a write command is received by the receiving unit, the writing unit writes data to a block associated with a selected channel number among blocks constituting the set.
    Type: Application
    Filed: August 25, 2011
    Publication date: September 27, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Shigehiro Asano, Shinichi Kanno, Kazuhiro Fukutomi, Akira Yamaga
  • Publication number: 20120166908
    Abstract: A semiconductor storage device, a method of controlling the same, and an error correction system allow reduction in power consumption and circuit scale without detriment to error correction capability. An error correction code (ECC) circuit of a solid state drive (SSD) performs first error correction on read data using a first error correction code (Hamming code), and further performs second error correction on the result of the first error correction using a second error correction code (BHC code). Furthermore, the ECC circuit performs third error correction on the result of the second error correction using a third error correction code (RS code).
    Type: Application
    Filed: December 22, 2011
    Publication date: June 28, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Akira Yamaga
  • Patent number: 8176389
    Abstract: A decoder device includes: a decoder that decodes data stored in a storage medium by performing error correction on the data, the error correction being capable of correcting code error and code erasure included in the data; a memory that stores a history of an address in the storage medium of a code included in the data, the code being detected to have the code error by the decoding unit; and a controller that controls the decoder to change a detail of the error correction based on the history stored in the memory.
    Type: Grant
    Filed: June 3, 2008
    Date of Patent: May 8, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Horisaki, Akira Yamaga
  • Patent number: 8086933
    Abstract: A semiconductor storage device, a method of controlling the same, and an error correction system allow reduction in power consumption and circuit scale without detriment to error correction capability. An error correction code (ECC) circuit of a solid state drive (SSD) performs first error correction on read data using a first error correction code (Hamming code), and further performs second error correction on the result of the first error correction using a second error correction code (BHC code). Furthermore, the ECC circuit performs third error correction on the result of the second error correction using a third error correction code (RS code).
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: December 27, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Akira Yamaga
  • Publication number: 20110047441
    Abstract: To provide a Chien search device and a Chien search method capable of performing a Chien search process at a high speed. The Chien search device calculates an error position at the time of correcting an error included in data read from a nonvolatile memory, and includes a first processing unit that performs a search process of an error position in at least one-bit unit to an error-correction area of input data, and a second processing unit that processes at one time plural bits in an non-error-correction-target area of the input data.
    Type: Application
    Filed: September 19, 2008
    Publication date: February 24, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Akira Yamaga
  • Publication number: 20100313099
    Abstract: A semiconductor storage device, a method of controlling the same, and an error correction system allow reduction in power consumption and circuit scale without detriment to error correction capability. An error correction code (ECC) circuit of a solid state drive (SSD) performs first error correction on read data using a first error correction code (Hamming code), and further performs second error correction on the result of the first error correction using a second error correction code (BHC code). Furthermore, the ECC circuit performs third error correction on the result of the second error correction using a third error correction code (RS code).
    Type: Application
    Filed: September 19, 2008
    Publication date: December 9, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Akira Yamaga
  • Publication number: 20090222708
    Abstract: An error correcting device for correcting erroneous data included in data read out from a nonvolatile memory includes a determining unit that determines whether the data read out from the nonvolatile memory include an error beyond an error correcting capability of the error correcting device. When the determining unit has determined that an error beyond the error correcting capability exists, the error correcting device does not perform the correction of the error.
    Type: Application
    Filed: February 27, 2009
    Publication date: September 3, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Akira YAMAGA