Patents by Inventor Naoya Tokiwa

Naoya Tokiwa 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).

  • Patent number: 8339833
    Abstract: A nonvolatile semiconductor storage device includes a memory core that includes plural banks, the bank including plural memory cells and a data write circuit that supplies a bias voltage to the memory cell, the memory core being logically divided into plural pages, the page including a predetermined number of memory cells belonging to a predetermined number of banks; and a control circuit that controls the data write circuit to perform page write in each write unit including a predetermined number of memory cells, pieces of data being written in the page in the page write, the control circuit performing the page write by repeating a step including a program operation and a verify operation, the control circuit performing the program operation and the verify operation in a next step or later only to the write unit in which the data write is not completed in the verify operation.
    Type: Grant
    Filed: February 19, 2010
    Date of Patent: December 25, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoya Tokiwa, Hiroshi Maejima
  • Publication number: 20120303871
    Abstract: According to one embodiment, a semiconductor memory device includes a memory cell array including a plurality of memory cells, a first register configured to store data of the memory cells, and a sequence control circuit configured to control the memory cell array and the first register. In at least a data read operation of the memory cells, the sequence control circuit reads out, from the memory cell array, data including flag information representing whether the number of failed bits is in an allowable range.
    Type: Application
    Filed: March 23, 2012
    Publication date: November 29, 2012
    Inventor: Naoya TOKIWA
  • Patent number: 8289800
    Abstract: A nonvolatile semiconductor memory device has an internal step-down power generation circuit and a memory circuit. The internal step-down power generation circuit generates a first internal power supply voltage from an external power supply voltage in an active state, and generates a second internal power supply voltage different from the first internal power supply voltage from the external power supply voltage in a standby state. The memory circuit includes a cell array containing a nonvolatile memory cell and a sense amplifier detecting data read from the cell array. The sense amplifier is supplied with a voltage generated by the internal step-down power generation circuit as an internal power supply voltage.
    Type: Grant
    Filed: January 26, 2010
    Date of Patent: October 16, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takuya Futatsuyama, Naoya Tokiwa
  • Publication number: 20120195119
    Abstract: In writing, a first write operation to a first memory cell is executed; and a second write operation for providing a first threshold-voltage distribution to a second memory cell adjacent to the first one, is executed. The first threshold voltage distribution is a lowest threshold-voltage distribution among the positive threshold voltage distributions. It is verified whether a desired threshold voltage distribution has been obtained in the first memory cell or not (first write verify operation), moreover, it is verified whether a first threshold voltage distribution or a threshold voltage distribution having a voltage level larger than the first threshold-voltage distribution has been obtained in the second memory cell or not (second write verify operation). A control circuit outputs results of the first write verify operation and the second write verify operation.
    Type: Application
    Filed: January 24, 2012
    Publication date: August 2, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yasushi NAGADOMI, Naoya TOKIWA
  • Patent number: 8228733
    Abstract: A three-dimensionally stacked nonvolatile semiconductor memory of an aspect of the present invention including conductive layers stacked on a semiconductor substrate in such a manner as to be insulated from one another, a bit line which is disposed on the stacked conductive layers, a semiconductor column which extends through the stacked conductive layers, word lines for which the stacked conductive layers except for the uppermost and lowermost conductive layers are used and which have a plate-like planar shape, memory cells provided at intersections of the word lines and the semiconductor column, a register circuit which has information to supply a potential suitable for each of the word lines, and a potential control circuit which reads the information retained in the register circuit in accordance with an input address signal of a word line and which supplies a potential suitable for the word line corresponding to the address signal.
    Type: Grant
    Filed: June 21, 2011
    Date of Patent: July 24, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoya Tokiwa, Hideo Mukai
  • Publication number: 20120113719
    Abstract: A nonvolatile semiconductor storage device is disclosed, which includes a memory cell array in which nonvolatile memory cells are arranged, a first data holding circuit which temporarily holds a collective processing unit of read or write data to be simultaneously read from or written to the memory cells, a circuit which takes out the data held in the first data holding circuit from the device, and a second data holding circuit in which data is automatically set at a time when power supply is turned on and in which the data is changeable based on a command input to the device, wherein the collective processing unit is equal to a sum of the number of units used within the device and the maximum number of units continuously output from the device to outside or input to the device from outside.
    Type: Application
    Filed: January 18, 2012
    Publication date: May 10, 2012
    Inventor: Naoya Tokiwa
  • Patent number: 8120957
    Abstract: A nonvolatile semiconductor storage device is disclosed, which includes a memory cell array in which nonvolatile memory cells are arranged, a first data holding circuit which temporarily holds a collective processing unit of read or write data to be simultaneously read from or written to the memory cells, a circuit which takes out the data held in the first data holding circuit from the device, and a second data holding circuit in which data is automatically set at a time when power supply is turned on and in which the data is changeable based on a command input to the device, wherein the collective processing unit is equal to a sum of the number of units used within the device and the maximum number of units continuously output from the device to outside or input to the device from outside.
    Type: Grant
    Filed: December 1, 2010
    Date of Patent: February 21, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Naoya Tokiwa
  • Patent number: 8117508
    Abstract: A non-volatile memory device including: a memory cell array storing an electrically rewritable resistance value as data in a non-volatile manner; a first cache circuit configured to hold program data to be programmed in the cell array; a second cache circuit configured to hold preprogrammed data read from an area of the cell array; and a judging circuit configured to compare and check the program data with the preprogrammed data, and judge whether there are one or more disagreement bits therebetween or not.
    Type: Grant
    Filed: December 30, 2009
    Date of Patent: February 14, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Naoya Tokiwa
  • Publication number: 20120026804
    Abstract: A semiconductor memory device comprises a plurality of memory layers arranged in multilayer, each memory layer including a cell array, the cell array containing a plurality of first parallel lines, a plurality of second parallel lines arranged crossing the first lines, and a plurality of memory cells connected at intersections of the first lines and the second lines; a pulse generator operative to generate pulses required for data access to the memory cell; and a control means operative to control the pulse generator such that the pulse output from the pulse generator has energy in accordance with the memory layer to which the access target memory cell belongs.
    Type: Application
    Filed: October 12, 2011
    Publication date: February 2, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroyuki NAGASHIMA, Naoya Tokiwa
  • Patent number: 8064272
    Abstract: A semiconductor memory device comprises a plurality of memory layers arranged in multilayer, each memory layer including a cell array, the cell array containing a plurality of first parallel lines, a plurality of second parallel lines arranged crossing the first lines, and a plurality of memory cells connected at intersections of the first lines and the second lines; a pulse generator operative to generate pulses required for data access to the memory cell; and a control means operative to control the pulse generator such that the pulse output from the pulse generator has energy in accordance with the memory layer to which the access target memory cell belongs.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: November 22, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Nagashima, Naoya Tokiwa
  • Publication number: 20110249498
    Abstract: A three-dimensionally stacked nonvolatile semiconductor memory of an aspect of the present invention including conductive layers stacked on a semiconductor substrate in such a manner as to be insulated from one another, a bit line which is disposed on the stacked conductive layers, a semiconductor column which extends through the stacked conductive layers, word lines for which the stacked conductive layers except for the uppermost and lowermost conductive layers are used and which have a plate-like planar shape, memory cells provided at intersections of the word lines and the semiconductor column, a register circuit which has information to supply a potential suitable for each of the word lines, and a potential control circuit which reads the information retained in the register circuit in accordance with an input address signal of a word line and which supplies a potential suitable for the word line corresponding to the address signal.
    Type: Application
    Filed: June 21, 2011
    Publication date: October 13, 2011
    Inventors: Naoya TOKIWA, Hideo Mukai
  • Patent number: 8000155
    Abstract: The present invention provides a method for writing data to a non-volatile memory device having first wirings and second wirings intersecting one another and memory cells arranged at each intersection therebetween, each of the memory cells having a variable resistive element and a rectifying element connected in series. According to the method, the second wirings are charged to a certain voltage not less than a rectifying-element threshold value, prior to a rise in a selected first wiring. Then, a selected first wiring is charged to a voltage required for writing or erasing, after which a selected second wiring is discharged.
    Type: Grant
    Filed: January 13, 2011
    Date of Patent: August 16, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshiaki Edahiro, Kazushige Kanda, Naoya Tokiwa, Takuya Futatsuyama, Koji Hosono, Shigeo Ohshima
  • Patent number: 7986557
    Abstract: A memory may include word lines; bit lines; cells provided corresponding to intersections between the word lines and the bit lines; sense amplifiers detecting data; a column decoder selecting a certain bit line for the sense amplifiers to output read data or receive write data; a row decoder configured to select a certain word line; a charge pump supplying power to the sense amplifiers, the column decoder, and the row decoder; a logic circuit controlling the sense amplifiers, the column decoder, and the row decoder based on an address selecting the memory cells; a first power source input applying a voltage to the logic circuit; and a second power source input applying a voltage higher than a voltage of the first power source input to the charge pump, and to supply power to the charge pump at least at a data reading time and a data writing time.
    Type: Grant
    Filed: July 31, 2009
    Date of Patent: July 26, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoya Tokiwa, Shigeo Ohshima
  • Patent number: 7983084
    Abstract: A three-dimensionally stacked nonvolatile semiconductor memory of an aspect of the present invention including conductive layers stacked on a semiconductor substrate in such a manner as to be insulated from one another, a bit line which is disposed on the stacked conductive layers, a semiconductor column which extends through the stacked conductive layers, word lines for which the stacked conductive layers except for the uppermost and lowermost conductive layers are used and which have a plate-like planar shape, memory cells provided at intersections of the word lines and the semiconductor column, a register circuit which has information to supply a potential suitable for each of the word lines, and a potential control circuit which reads the information retained in the register circuit in accordance with an input address signal of a word line and which supplies a potential suitable for the word line corresponding to the address signal.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: July 19, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoya Tokiwa, Hideo Mukai
  • Patent number: 7965552
    Abstract: A non-volatile semiconductor memory device includes: a memory cell array; a bad block position data register area defined in the memory cell array to store bad block position data; an address decoder circuit configured to select a block in the cell array; and bad block flag latches disposed in the address decoder circuit, bad block flags being set in the bad block flag latches in accordance with the bad block position data read out the bad block position data register area, wherein the bad block position data in the bad block position data register area are defined by such a bit position assignment scheme that one bit is assigned to one block under the condition that block positions in the cell array and column positions in one page are set in one-to-one correspondence.
    Type: Grant
    Filed: December 24, 2008
    Date of Patent: June 21, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masanobu Shirakawa, Naoya Tokiwa
  • Publication number: 20110134681
    Abstract: A semiconductor memory device comprises a plurality of memory layers arranged in multi layer, each memory layer including a cell array, the cell array containing a plurality of first parallel lines, a plurality of second parallel lines arranged crossing the first lines, and a plurality of memory cells connected at intersections of the first lines and the second lines; a pulse generator operative to generate pulses required for data access to the memory cell; and a control means operative to control the pulse generator such that the pulse output from the pulse generator has energy in accordance with the memory layer to which the access target memory cell belongs.
    Type: Application
    Filed: February 15, 2011
    Publication date: June 9, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroyuki NAGASHIMA, Naoya Tokiwa
  • Patent number: 7952958
    Abstract: There is provided a non-volatile memory having electrically rewritable non-volatile memory cells arranged therein. A controller controls operation at the non-volatile memory. The non-volatile memory comprises a status output section configured to output status information indicating a status of read operation, write operation or erase operation in the non-volatile memory cell. The controller comprises a control signal generating section configured to output a control signal for a certain operation in the non-volatile memory, and a control signal switching section configured to instruct the control signal generating section to switch the control signal based on the status information.
    Type: Grant
    Filed: July 22, 2009
    Date of Patent: May 31, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kosuke Yanagidaira, Toshihiro Suzuki, Naoya Tokiwa
  • Publication number: 20110103135
    Abstract: The present invention provides a method for writing data to a non-volatile memory device having first wirings and second wirings intersecting one another and memory cells arranged at each intersection therebetween, each of the memory cells having a variable resistive element and a rectifying element connected in series. According to the method, the second wirings are charged to a certain voltage not less than a rectifying-element threshold value, prior to a rise in a selected first wiring. Then, a selected first wiring is charged to a voltage required for writing or erasing, after which a selected second wiring is discharged.
    Type: Application
    Filed: January 13, 2011
    Publication date: May 5, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toshiaki EDAHIRO, Kazushige Kanda, Naoya Tokiwa, Takuya Futatsuyama, Koji Hosono, Shigeo Ohshima
  • Publication number: 20110069549
    Abstract: A nonvolatile semiconductor storage device is disclosed, which includes a memory cell array in which nonvolatile memory cells are arranged, a first data holding circuit which temporarily holds a collective processing unit of read or write data to be simultaneously read from or written to the memory cells, a circuit which takes out the data held in the first data holding circuit from the device, and a second data holding circuit in which data is automatically set at a time when power supply is turned on and in which the data is changeable based on a command input to the device, wherein the collective processing unit is equal to a sum of the number of units used within the device and the maximum number of units continuously output from the device to outside or input to the device from outside.
    Type: Application
    Filed: December 1, 2010
    Publication date: March 24, 2011
    Inventor: Naoya TOKIWA
  • Patent number: 7911845
    Abstract: A non-volatile semiconductor memory device includes: a memory cell array having electrically rewritable and non-volatile memory cells arranged; a data register circuit configured to hold write data to be written into the memory cell array; and an address decode circuit configured to decode a write address signal and control the write data-loading in the data register circuit, the address decode circuit being settable in such a multiple selection mode that the same write data is loaded in multiple registers in the data register circuit in correspondence to multiple addresses.
    Type: Grant
    Filed: January 8, 2009
    Date of Patent: March 22, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoya Tokiwa, Masanobu Shirakawa