Patents by Inventor Naofumi Abiko

Naofumi Abiko 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: 20160322110
    Abstract: According to one embodiment, there is provided a semiconductor storage device including a memory cell array and a control circuit. The memory cell array has multiple memory cells connected to word lines and bit lines. The control circuit sets a value of a control voltage used to control voltages on the bit lines at a first value and, if receiving a first command including a change request to change the control voltage and including a to-be-changed-to second value, changes the value of the control voltage used to control the voltages on the bit lines from the first value to the second value, according to the change request.
    Type: Application
    Filed: August 24, 2015
    Publication date: November 3, 2016
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Naofumi ABIKO, Yoshikazu HARADA
  • Publication number: 20160260497
    Abstract: According to one embodiment, a device includes a memory cell array including memory cells and controller. The controller executes verification of second data in a first verify period in a first verify operation and verification of third data in a second verify period in the first verify operation. The controller excludes memory cells to be written first data from a target of the first verify operation at a first time in the first verify period and excludes memory cells to be written the second data from the target at a second time in the second verify period.
    Type: Application
    Filed: September 4, 2015
    Publication date: September 8, 2016
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshikazu HARADA, Masahiro YOSHIHARA, Naofumi ABIKO
  • Publication number: 20160189777
    Abstract: A semiconductor storage device has a memory string including a memory cell, a bit line electrically connected to one end of the memory string, and a sense amplifier electrically connected to the bit line. The sense amplifier has a first transistor, one end of which is connected to a first node on an electric current path of the bit line, and another end of which is electrically connected to a second node, a second transistor electrically connected between the second node and a sense node, and a third transistor, a gate of which is connected to the first node, and the third transistor being electrically connected between the second node and a third node whose voltage can be adjusted.
    Type: Application
    Filed: March 7, 2016
    Publication date: June 30, 2016
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Masahiro YOSHIHARA, Naofumi ABIKO
  • Patent number: 9070444
    Abstract: A semiconductor memory device includes a memory cell array including memory cells arranged therein. A first latch circuit temporarily holds data to perform a read operation and a write operation on the memory cell array. The second latch circuit temporarily holds a control signal. A control circuit controls the memory cell array, the first latch circuit and the second latch circuit. The control circuit limits an operation of the first latch circuit in a state after an operation on the memory cell array has been finished, and limits an operation of the second latch circuit based on a command supplied from external.
    Type: Grant
    Filed: July 23, 2013
    Date of Patent: June 30, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naofumi Abiko, Masahiro Yoshihara, Akio Sugahara, Yoshikazu Harada
  • Patent number: 9001582
    Abstract: A nonvolatile semiconductor memory device includes memory cells arranged into memory strings with word lines each connected to a different memory cell of the memory strings. The device also includes bit lines each connected to a different memory string and a column decoder connected to the bit lines. The column decoder includes sense amplifiers, data latches, and a data bus connecting sense amplifiers and data latches. The data bus is divided into at least two portions and includes a first portion connected to a second portion by a switch.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: April 7, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomofumi Fujimura, Naofumi Abiko
  • Patent number: 8923074
    Abstract: A sense amplifier circuit is connected to a bit-line and senses and amplifies a signal read from a memory cell. A first data latch is connected to a sense amplifier via a first bus. A second data latch is connected to a second bus. A plurality of circuit groups are repeatedly provided in a first direction, each circuit group including one sense amplifier circuit and one first data latch. The second data latch is provided between the circuit groups and an input/output buffer.
    Type: Grant
    Filed: March 28, 2012
    Date of Patent: December 30, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masahiro Yoshihara, Naofumi Abiko, Katsumi Abe
  • Publication number: 20140269097
    Abstract: According to one embodiment, a non-volatile semiconductor memory device includes a memory cell array and a sense amplifier. The memory cell array includes a plurality of memory cell transistors. The sense amplifier reads data held in the memory cell transistors. The sense amplifier writes data to the memory cell transistors. The sense amplifier includes a first sense unit, a first operational unit, a second sense unit, and a second operational unit. The first sense unit includes a first sub-amplifier group and a first switch group. The second sense unit includes a second sub-amplifier group and a second switch group. The first sub-amplifier group is electrically connected to a first data bus. The second sub-amplifier group is electrically connected to a second data bus. The first operational unit is electrically connected to the first data bus and the second data bus.
    Type: Application
    Filed: September 9, 2013
    Publication date: September 18, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroyuki KAGA, Masahiro Yoshihara, Naofumi Abiko, Yoshikazu Harada
  • Publication number: 20140241072
    Abstract: A semiconductor memory device includes a memory cell array including memory cells arranged therein. A first latch circuit temporarily holds data to perform a read operation and a write operation on the memory cell array. The second latch circuit temporarily holds a control signal. A control circuit controls the memory cell array, the first latch circuit and the second latch circuit. The control circuit limits an operation of the first latch circuit in a state after an operation on the memory cell array has been finished, and limits an operation of the second latch circuit based on a command supplied from external.
    Type: Application
    Filed: July 23, 2013
    Publication date: August 28, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naofumi ABIKO, Masahiro Yoshihara, Akio Sugahara, Yoshikazu Harada
  • Patent number: 8599613
    Abstract: According to one embodiment, a nonvolatile semiconductor memory includes a memory cell array including memory cells of a first unit in which read and write are parallelly performed, n (n is a natural number of not less than 2) sense amplifiers, n detection circuits corresponding to the n sense amplifiers, an accumulator configured to divide the first unit data read from the memory cell array into z (z is a natural number) second unit data and accumulate a fail bit for which the write is incomplete for the second unit data, and a control circuit configured to control an operation of detecting the fail bit after the write.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: December 3, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naofumi Abiko, Masahiro Yoshihara
  • Publication number: 20130250684
    Abstract: A nonvolatile semiconductor memory device includes memory cells arranged into memory strings with word lines each connected to a different memory cell of the memory strings. The device also includes bit lines each connected to a different memory string and a column decoder connected to the bit lines. The column decoder includes sense amplifiers, data latches, and a data bus connecting sense amplifiers and data latches. The data bus is divided into at least two portions and includes a first portion connected to a second portion by a switch.
    Type: Application
    Filed: March 4, 2013
    Publication date: September 26, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tomofumi FUJIMURA, Naofumi ABIKO
  • Patent number: 8472248
    Abstract: According to one embodiment, a semiconductor memory includes a memory cell array which includes memory cells, the memory cells being arranged along a row direction and a column direction and storing data respectively corresponding to thresholds, a row control circuit which controls a row of the memory cell array, and a column control circuit which includes a control unit, the control unit generating a signal to control elements corresponding to column of the memory cell array in accordance with a pointer corresponding to an external address signal.
    Type: Grant
    Filed: September 18, 2011
    Date of Patent: June 25, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Kaga, Masahiro Yoshihara, Naofumi Abiko
  • Patent number: 8363486
    Abstract: According to one embodiment, in a nonvolatile semiconductor memory device, a data latch circuit which is connected to a sense amplifier circuit controls a data writing operation and a data reading operation to and from a nonvolatile memory cell array through a data bus, and outputs the stored data to the data bus when the sense amplifier circuit performs the data writing operation. The data latch circuit is provided with two nodes respectively storing and outputting normal data and reverse data which are connected to the data bus.
    Type: Grant
    Filed: September 17, 2010
    Date of Patent: January 29, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Naofumi Abiko
  • Publication number: 20120250409
    Abstract: According to one embodiment, a semiconductor memory includes a memory cell array which includes memory cells, the memory cells being arranged along a row direction and a column direction and storing data respectively corresponding to thresholds, a row control circuit which controls a row of the memory cell array, and a column control circuit which includes a control unit, the control unit generating a signal to control elements corresponding to column of the memory cell array in accordance with a pointer corresponding to an external address signal.
    Type: Application
    Filed: September 18, 2011
    Publication date: October 4, 2012
    Inventors: Hiroyuki KAGA, Masahiro Yoshihara, Naofumi Abiko
  • Publication number: 20120250424
    Abstract: A sense amplifier circuit is connected to a bit-line and senses and amplifies a signal read from a memory cell. A first data latch is connected to a sense amplifier via a first bus. A second data latch is connected to a second bus. A plurality of circuit groups are repeatedly provided in a first direction, each circuit group comprising one sense amplifier circuit and one first data latch. The second data latch is provided between the circuit groups and an input/output buffer.
    Type: Application
    Filed: March 28, 2012
    Publication date: October 4, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Masahiro YOSHIHARA, Naofumi Abiko, Katsumi Abe
  • Publication number: 20120250411
    Abstract: According to one embodiment, a nonvolatile semiconductor memory includes a memory cell array including memory cells of a first unit in which read and write are parallelly performed, n (n is a natural number of not less than 2) sense amplifiers, n detection circuits corresponding to the n sense amplifiers, an accumulator configured to divide the first unit data read from the memory cell array into z (z is a natural number) second unit data and accumulate a fail bit for which the write is incomplete for the second unit data, and a control circuit configured to control an operation of detecting the fail bit after the write.
    Type: Application
    Filed: March 23, 2012
    Publication date: October 4, 2012
    Inventors: Naofumi ABIKO, Masahiro Yoshihara
  • Patent number: 8203885
    Abstract: According to an embodiment, a nonvolatile semiconductor memory system includes: a nonvolatile semiconductor memory; and a memory controller having: a memory interface unit that inputs commands to the nonvolatile semiconductor memory and inputs or outputs data between the nonvolatile semiconductor memory; a memory that stores writing information indicating a memory cell transistor that is written the latest in each of the NAND cell units; and a processor that sets a read voltage based on the writing information to read out data from the memory cell transistors connected to a first word line; wherein a row controller is configured to set a plurality of levels of the read voltage to be applied to the first word line, with respect to one threshold for discriminating data stored in a memory cell transistors.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: June 19, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naofumi Abiko, Takuya Futatsuyama
  • Publication number: 20120002469
    Abstract: A nonvolatile semiconductor memory device according to an embodiment includes: a memory cell array including a plurality of memory cells selected by word lines and bit lines, each memory cell being capable of storing N-bit data, a set of n-th bits of a plurality of memory cells selected by one of the word lines constituting an n-th physical page, and a predetermined number of the bit lines constituting one column; and a data writing unit that divides each of first to N-th input data of the length of the physical page or less input from the outside into unit data of the length of the column, changes at least a portion of the order of unit data of the first to N-th input data of a predetermined column in the predetermined column before data writing, and performs writing.
    Type: Application
    Filed: March 18, 2011
    Publication date: January 5, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Akihiro IMAMOTO, Naofumi Abiko
  • Publication number: 20110267884
    Abstract: According to an embodiment, a nonvolatile semiconductor memory system includes: a nonvolatile semiconductor memory; and a memory controller having: a memory interface unit that inputs commands to the nonvolatile semiconductor memory and inputs or outputs data between the nonvolatile semiconductor memory; a memory that stores writing information indicating a memory cell transistor that is written the latest in each of the NAND cell units; and a processor that sets a read voltage based on the writing information to read out data from the memory cell transistors connected to a first word line; wherein a row controller is configured to set a plurality of levels of the read voltage to be applied to the first word line, with respect to one threshold for discriminating data stored in a memory cell transistors.
    Type: Application
    Filed: July 8, 2011
    Publication date: November 3, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: NAOFUMI ABIKO, TAKUYA FUTATSUYAMA
  • Patent number: 8009480
    Abstract: According to an embodiment, a nonvolatile semiconductor memory system includes: a nonvolatile semiconductor memory; and a memory controller having: a memory interface unit that inputs commands to the nonvolatile semiconductor memory and inputs or outputs data between the nonvolatile semiconductor memory; a memory that stores writing information indicating a memory cell transistor that is written the latest in each of the NAND cell units; and a processor that sets a read voltage based on the writing information to read out data from the memory cell transistors connected to a first word line; wherein a row controller is configured to set a plurality of levels of the read voltage to be applied to the first word line, with respect to one threshold for discriminating data stored in a memory cell transistors.
    Type: Grant
    Filed: December 3, 2009
    Date of Patent: August 30, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naofumi Abiko, Takuya Futatsuyama
  • Publication number: 20110141814
    Abstract: According to one embodiment, in a nonvolatile semiconductor memory device, a data latch circuit which is connected to a sense amplifier circuit controls a data writing operation and a data reading operation to and from a nonvolatile memory cell array through a data bus, and outputs the stored data to the data bus when the sense amplifier circuit performs the data writing operation. The data latch circuit is provided with two nodes respectively storing and outputting normal data and reverse data which are connected to the data bus.
    Type: Application
    Filed: September 17, 2010
    Publication date: June 16, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Naofumi ABIKO