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).

  • Publication number: 20070297236
    Abstract: A semiconductor memory device includes: a memory cell array with electrically rewritable and non-volatile memory cells arranged therein; a data storage circuit configured to store data simultaneously read from or written into the memory cell array, the data constituting a collective processing unit; and a data state judgment circuit configured to sequentially judge the data states of multiple divided areas, which are obtained by dividing the collective processing unit.
    Type: Application
    Filed: May 29, 2007
    Publication date: December 27, 2007
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Naoya Tokiwa
  • Publication number: 20070247963
    Abstract: A semiconductor memory device includes: a memory cell array, in which electrically rewritable and non-volatile memory cells are arranged; a sense amplifier circuit configured to be coupled to the memory cell array; a data transfer circuit disposed between the sense amplifier circuit and data input/output ports; a control signal generation circuit configured to generate a plurality of control signals based on a reference clock signal externally supplied, the control signals serving for controlling data input and output of the sense amplifier circuit and data transferring timing in the data transfer circuit; and an internal clock signal generation circuit configured to generate an internal clock signal based on the reference clock signal for serving as the basis of the control signals, the internal clock signal having the same clock cycle as the reference clock signal and a constant duty ratio without regard to the duty ratio of the reference clock signal.
    Type: Application
    Filed: June 22, 2007
    Publication date: October 25, 2007
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Naoya TOKIWA
  • Publication number: 20070147144
    Abstract: A semiconductor integrated circuit device includes a memory cell array having a plurality of blocks, a storage unit, a block replacement information register group, and a bad block flag register group. The storage unit includes a block replacement information registration area with which it is possible to register block replacement information, and a bad block information registration area with which it is possible to register bad block information. The block replacement information register group is set in accordance with the block replacement information read out of the storage unit during a boot sequence, and the bad block flag register group is set in accordance with both of the block replacement information and the bad block information read out of the storage unit during the boot sequence.
    Type: Application
    Filed: December 26, 2006
    Publication date: June 28, 2007
    Inventor: Naoya Tokiwa
  • Patent number: 7236424
    Abstract: A semiconductor memory device includes: a memory cell array, in which electrically rewritable and non-volatile memory cells are arranged; a sense amplifier circuit configured to be coupled to the memory cell array; a data transfer circuit disposed between the sense amplifier circuit and data input/output ports; a control signal generation circuit configured to generate a plurality of control signals based on a reference clock signal externally supplied, the control signals serving for controlling data input and output of the sense amplifier circuit and data transferring timing in the data transfer circuit; and an internal clock signal generation circuit configured to generate an internal clock signal based on the reference clock signal for serving as the basis of the control signals, the internal clock signal having the same clock cycle as the reference clock signal and a constant duty ratio without regard to the duty ratio of the reference clock signal.
    Type: Grant
    Filed: March 23, 2005
    Date of Patent: June 26, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Naoya Tokiwa
  • Publication number: 20060044874
    Abstract: A semiconductor memory device includes: a memory cell array, in which electrically rewritable and non-volatile memory cells are arranged; a sense amplifier circuit configured to be coupled to the memory cell array; a data transfer circuit disposed between the sense amplifier circuit and data input/output ports; a control signal generation circuit configured to generate a plurality of control signals based on a reference clock signal externally supplied, the control signals serving for controlling data input and output of the sense amplifier circuit and data transferring timing in the data transfer circuit; and an internal clock signal generation circuit configured to generate an internal clock signal based on the reference clock signal for serving as the basis of the control signals, the internal clock signal having the same clock cycle as the reference clock signal and a constant duty ratio without regard to the duty ratio of the reference clock signal.
    Type: Application
    Filed: March 23, 2005
    Publication date: March 2, 2006
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Naoya Tokiwa
  • Patent number: 6950345
    Abstract: A nonvolatile semiconductor memory device with a function of executing a verify operation for write data that is input from outside includes a memory cell array including memory cells arranged in a matrix, and a password storage area for storing password data, an input buffer that receives data input from outside, a first retaining circuit that retains input password data or write data, which is input to the input buffer, a verify sense amplifier that detects, at a time of the verify operation, the password data that is read out of the password storage area or data that is read out of the memory cell array, and a coincidence determination circuit that determines whether the input password data coincides with the read-out password data, or determines whether the write data coincides with the read-out data.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: September 27, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Naoya Tokiwa
  • Publication number: 20050201156
    Abstract: A nonvolatile semiconductor memory device with a function of executing a verify operation for write data that is input from outside includes a memory cell array including memory cells arranged in a matrix, and a password storage area for storing password data, an input buffer that receives data input from outside, a first retaining circuit that retains input password data or write data, which is input to the input buffer, a verify sense amplifier that detects, at a time of the verify operation, the password data that is read out of the password storage area or data that is read out of the memory cell array, and a coincidence determination circuit that determines whether the input password data coincides with the read-out password data, or determines whether the write data coincides with the read-out data.
    Type: Application
    Filed: June 24, 2004
    Publication date: September 15, 2005
    Inventor: Naoya Tokiwa
  • Patent number: 6937524
    Abstract: A non-volatile semiconductor memory device capable of performing page programming at high speeds is provided. This nonvolatile memory device includes a cell array with a matrix of rows and columns of electrically writable and erasable nonvolatile memory cells, and a write control circuit which writes or “programs” one-page data into this cell array at a plurality of addresses within one page. The write control circuit is operable to iteratively perform iteration of a write operation for the plurality of addresses corresponding to one page and iteration of a verify-read operation of the plurality of addresses after writing until verify-read check is passed with respect to every address involved. Regarding an address or addresses with no cells to be written any more, the write control circuit skips the write operation and the after-write verify-read operation.
    Type: Grant
    Filed: June 11, 2003
    Date of Patent: August 30, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Shiga, Naoya Tokiwa
  • Publication number: 20040027901
    Abstract: A non-volatile semiconductor memory device capable of performing page programming at high speeds is provided. This nonvolatile memory device includes a cell array with a matrix of rows and columns of electrically writable and erasable nonvolatile memory cells, and a write control circuit which writes or “programs” one-page data into this cell array at a plurality of addresses within one page. The write control circuit is operable to iteratively perform iteration of a write operation for the plurality of addresses corresponding to one page and iteration of a verify-read operation of the plurality of addresses after writing until verify-read check is passed with respect to every address involved. Regarding an address or addresses with no cells to be written any more, the write control circuit skips the write operation and the after-write verify-read operation.
    Type: Application
    Filed: June 11, 2003
    Publication date: February 12, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hitoshi Shiga, Naoya Tokiwa