Patents by Inventor Koichi Kawai

Koichi Kawai 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: 20070076487
    Abstract: A semiconductor integrated circuit device has data rewritable nonvolatile memory cells which are formed on a semiconductor chip and in which data of three or more values can be stored. The nonvolatile memory cell has two or more write levels and two or more write threshold voltages are used. The two or more threshold voltage distribution widths are changed according to the two or more write levels.
    Type: Application
    Filed: September 19, 2006
    Publication date: April 5, 2007
    Inventors: Ken Takeuchi, Koichi Kawai
  • Publication number: 20070047360
    Abstract: Data read from memory cells of one page in a memory cell array that corresponds to a page address of a copy source is sensed and latched by a sense/latch circuit. The sense/latch circuit has a plurality of latch circuits, and the plurality of latch circuits is specified according to the column address. The latch circuit specified in accordance with the column address is supplied with the data to be rewritten. The latch circuit specified in accordance with its address latches the data to be rewritten, whereby rewriting of the data is performed. The data of one page after rewritten is written into the page in the memory cell array that corresponds to the page address of a copy destination.
    Type: Application
    Filed: October 17, 2006
    Publication date: March 1, 2007
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Koichi Kawai, Kenichi Imamiya, Hiroshi Nakamura
  • Patent number: 7180778
    Abstract: Data read from memory cells of one page in a memory cell array that corresponds to a page address of a copy source is sensed and latched by a sense/latch circuit. The sense/latch circuit has a plurality of latch circuits, and the plurality of latch circuits is specified according to the column address. The latch circuit specified in accordance with the column address is supplied with the data to be rewritten. The latch circuit specified in accordance with its address latches the data to be rewritten, whereby rewriting of the data is performed. The data of one page after rewritten is written into the page in the memory cell array that corresponds to the page address of a copy destination.
    Type: Grant
    Filed: September 2, 2005
    Date of Patent: February 20, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Kawai, Kenichi Imamiya, Hiroshi Nakamura
  • Publication number: 20070036016
    Abstract: A nonvolatile semiconductor memory device includes a memory cell array, read circuit, program circuit, read voltage generating circuit, memory circuit and switching circuit. The read voltage generating circuit generates and supplies a read voltage to the read circuit. The memory circuit stores information which changes the temperature characteristic of a memory cell in the memory cell array. The switching circuit changes the temperature dependency of read voltage generated from the read voltage generating circuit based on information stored in the memory circuit.
    Type: Application
    Filed: September 12, 2006
    Publication date: February 15, 2007
    Inventors: Ken Takeuchi, Takuya Futatsuyama, Koichi Kawai
  • Patent number: 7170780
    Abstract: A semiconductor memory device includes: a memory cell array with electrically rewritable and non-volatile memory cells arranged therein, each memory cell storing one of first, second, third and fourth data defined as being arranged in order of threshold voltage height; a read/write circuit configured to read data of and write data in the memory cell array; and a controller configured to control the read/write circuit so as to execute first and second write sequences, the first write sequence being defined as to write the second data into a first selected memory cell or cells within a selected page of the memory cell array which has been initialized in the first data state, the second write sequence being defined as to write the fourth data into a second selected memory cell or cells within memory cells storing the second or first data in the selected page, and successively write the third data into a third selected memory cell or cells within memory cells storing the first or second data in the selected page.
    Type: Grant
    Filed: February 16, 2005
    Date of Patent: January 30, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Koichi Kawai
  • Patent number: 7164605
    Abstract: A semiconductor memory device includes: a plurality of cell array blocks in each of which a plurality of memory cells are arranged; address decode circuits for selecting memory cells in the cell array blocks; sense amplifier circuits for reading cell data of the cell array blocks; and a busy signal generation circuit for generating a busy signal to the chip external, wherein in a first read cycle selecting a first area in a first cell array block, cell data read operations for the first area of the first cell array block and a second area of a second cell array block are simultaneously executed, while the busy signal generation circuit generates a true busy signal, and then a read data output operation is executed for outputting the read out data of the first area held in the sense amplifier circuits to the chip external, and in a second read cycle selecting the second area in the second cell array block, after the busy signal generation circuit has output a dummy busy signal shorter in time length than the t
    Type: Grant
    Filed: December 19, 2005
    Date of Patent: January 16, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Kawai, Tomoharu Tanaka, Noboru Shibata
  • Publication number: 20070008803
    Abstract: A semiconductor device of this invention includes an initialization circuit for initializing a predetermined circuit in accordance with the level of a power source voltage, and a status setting unit for setting the status. of the semiconductor device to “busy” during a period in which the initialization circuit performs initialization.
    Type: Application
    Filed: September 15, 2006
    Publication date: January 11, 2007
    Inventors: Kazushige Kanda, Koichi Kawai, Hiroshi Nakamura, Kenichi Imamiya
  • Publication number: 20070002635
    Abstract: In a semiconductor integrated circuit, an internal circuit is capable of executing a first operation and a second operation concurrently, and an output circuit outputs to the outside of the semiconductor integrated circuit information indicating whether or not the first operation is being executed and information indicating whether or not the second operation is executable.
    Type: Application
    Filed: September 5, 2006
    Publication date: January 4, 2007
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Toshio Yamamura, Koji Hosono, Koichi Kawai
  • Patent number: 7145806
    Abstract: A semiconductor memory device includes: a memory cell array having a plurality of word lines and a plurality of bit lines, which cross each other, and electrically rewritable and non-volatile memory cells disposed at crossings thereof; a read/write circuit configured to write data into a selected memory cell with applying a write voltage to a selected word line, and detect a discharge state of a selected bit line to read data of the selected memory cell after having precharged the selected bit line to a certain voltage; and a controller configured to control the read/write circuit to execute a write sequence by repeat of a write operation and a verify-read operation for the selected memory cell in such a way as to start a precharge operation of the selected bit line for the verify-read operation prior to the ending time of the write operation in the write sequence.
    Type: Grant
    Filed: February 16, 2005
    Date of Patent: December 5, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Koichi Kawai
  • Publication number: 20060256627
    Abstract: A semiconductor memory device including: a memory cell array with electrically rewritable and non-volatile memory cells arranged therein; a sense amplifier circuit configured to read data of the memory cell array; first data hold circuits configured to hold data for designating whether each column of the memory cell array is defective or not; and a second data hold circuit configured to hold data read out of the first data hold circuits, and to control skipping a defective column address of the memory cell array in accordance with the data read out of the first data hold circuit.
    Type: Application
    Filed: July 18, 2006
    Publication date: November 16, 2006
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Koichi Kawai
  • Patent number: 7130217
    Abstract: Data read from memory cells of one page in a memory cell array that corresponds to a page address of a copy source is sensed and latched by a sense/latch circuit. The sense/latch circuit has a plurality of latch circuits, and the plurality of latch circuits is specified according to the column address. The latch circuit specified in accordance with the column address is supplied with the data to be rewritten. The latch circuit specified in accordance with its address latches the data to be rewritten, whereby rewriting of the data is performed. The data of one page after rewritten is written into the page in the memory cell array that corresponds to the page address of a copy destination.
    Type: Grant
    Filed: January 9, 2006
    Date of Patent: October 31, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Kawai, Kenichi Imamiya, Hiroshi Nakamura
  • Patent number: 7123515
    Abstract: In a semiconductor integrated circuit, an internal circuit is capable of executing a first operation and a second operation concurrently, and an output circuit outputs to the outside of the semiconductor integrated circuit information indicating whether or not the first operation is being executed and information indicating whether or not the second operation is executable.
    Type: Grant
    Filed: May 3, 2005
    Date of Patent: October 17, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Toshio Yamamura, Koji Hosono, Koichi Kawai
  • Patent number: 7123526
    Abstract: A semiconductor device of this invention includes an initialization circuit for initializing a predetermined circuit in accordance with the level of a power source voltage, and a status setting unit for setting the status of the semiconductor device to “busy” during a period in which the initialization circuit performs initialization.
    Type: Grant
    Filed: January 24, 2006
    Date of Patent: October 17, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazushige Kanda, Koichi Kawai, Hiroshi Nakamura, Kenichi Imamiya
  • Patent number: 7117296
    Abstract: A non-volatile semiconductor memory device includes a memory cell array in which electrically erasable and programmable memory cells are arrayed, each of the memory cells storing therein a first logic state with a threshold voltage lower than or equal to a first value or a second logic state with a threshold voltage higher than or equal to a second value that is higher than the first value, a data hold circuit for holding program data and sensing data as read out of the memory cell array, and a controller configured to control a program sequence, wherein the controller has the control functions of: a program control function for applying a program voltage to a selected memory cell of the memory cell array to let the data shift from the first logic state to the second logic state; a program verify control function for verifying that the programmed data of the selected memory cell shifted to the second logic state; an erratic program verify control function for checking that the threshold voltage of a memory ce
    Type: Grant
    Filed: April 28, 2005
    Date of Patent: October 3, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hosono, Kenichi Imamiya, Hiroshi Nakamura, Mikito Nakabayashi, Koichi Kawai
  • Patent number: 7110294
    Abstract: A semiconductor memory device including: a memory cell array with electrically rewritable and non-volatile memory cells arranged therein; a sense amplifier circuit configured to read data of the memory cell array; first data hold circuits configured to hold data for designating whether each column of the memory cell array is defective or not; and a second data hold circuit configured to hold data read out of the first dada hold circuits, and control to skip a defective column address of the memory cell array in accordance with the data read out of the first data hold circuit.
    Type: Grant
    Filed: February 16, 2005
    Date of Patent: September 19, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Koichi Kawai
  • Publication number: 20060171210
    Abstract: A nonvolatile semiconductor memory device includes a memory cell array, interface, and write circuit. The write circuit can selectively write data in the memory cell array by first write procedures or second write procedures in accordance with a data write command input to the interface. When a data write command by the first write procedures is input from the interface, the write circuit executes the command when flag data has a first value and does not execute the command when the flag data has a second value.
    Type: Application
    Filed: March 29, 2006
    Publication date: August 3, 2006
    Inventors: Hiroyuki Nagashima, Tomoharu Tanaka, Koichi Kawai, Khandker Quader
  • Publication number: 20060164897
    Abstract: Data read from memory cells of one page in a memory cell array that corresponds to a page address of a copy source is sensed and latched by a sense/latch circuit. The sense/latch circuit has a plurality of latch circuits, and the plurality of latch circuits is specified according to the column address. The latch circuit specified in accordance with the column address is supplied with the data to be rewritten. The latch circuit specified in accordance with its address latches the data to be rewritten, whereby rewriting of the data is performed. The data of one page after rewritten is written into the page in the memory cell array that corresponds to the page address of a copy destination.
    Type: Application
    Filed: January 9, 2006
    Publication date: July 27, 2006
    Inventors: Koichi Kawai, Kenichi Imamiya, Hiroshi Nakamura
  • Publication number: 20060164886
    Abstract: A nonvolatile semiconductor memory device includes a memory cell array constituted by a plurality of memory blocks, an interface, a write circuit, and a read circuit. A protect flag is written in the memory block. The readout protect flag can be output to an external device through the interface. When a write command is input from the interface, the write circuit executes the write command when the protect flag in the selected memory block has a first value and does not execute the write command when the protect flag has a second value.
    Type: Application
    Filed: March 24, 2006
    Publication date: July 27, 2006
    Inventors: Tomoharu Tanaka, Koichi Kawai, Khandker Quader
  • Patent number: 7082054
    Abstract: Data read from memory cells of one page in a memory cell array that corresponds to a page address of a copy source is sensed and latched by a sense/latch circuit. The sense/latch circuit has a plurality of latch circuits, and the plurality of latch circuits is specified according to the column address. The latch circuit specified in accordance with the column address is supplied with the data to be rewritten. The latch circuit specified in accordance with its address latches the data to be rewritten, whereby rewriting of the data is performed. The data of one page after rewritten is written into the page in the memory cell array that corresponds to the page address of a copy destination.
    Type: Grant
    Filed: September 2, 2005
    Date of Patent: July 25, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Kawai, Kenichi Imamiya, Hiroshi Nakamura
  • Patent number: 7061799
    Abstract: The nonvolatile semiconductor memory device includes a memory cell array containing a plurality of nonvolatile memory cells and an initial setup data region in which initial setup data specified to determine operation conditions of the device is to be written. The device further includes a detection circuit which detects turn-on of power. The device further includes a readout circuit which reads out the initial setup data from the initial setup data region of the memory cell array upon detecting power-on by the detection circuit. The device further includes a determination circuit which determines whether the initial setup data read out by the readout circuit is effective or ineffective. The device further includes a setup circuit which sets up the device in an operative-prohibiting status when the initial setup data is determined as ineffective by the determination circuit.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: June 13, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Kawai, Kenichi Imamiya, Koji Hosono