Patents by Inventor Toshitsugu Sakamoto

Toshitsugu Sakamoto 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: 11481535
    Abstract: A numerical information generating apparatus receives information of a programmable logic integrated circuit that includes a plurality of crossbar switches each including resistance change elements, calculates, for each of the plurality of crossbar switches, a base delay that is a delay in which influence of a load capacitance of other crossbar switch is excluded and a correction delay that is a delay caused by influence of a fanout of other crossbar switch, and further calculates a delay of each of the plurality of crossbar switches based on the base delay and the correction delay corresponding to each of the plurality of crossbar switches.
    Type: Grant
    Filed: May 14, 2019
    Date of Patent: October 25, 2022
    Assignee: NANOBRIDGE SEMICONDUCTOR, INC.
    Inventors: Ayuka Tada, Toshitsugu Sakamoto, Makoto Miyamura, Yukihide Tsuji, Ryusuke Nebashi, Xu Bai
  • Patent number: 11139024
    Abstract: In order to eliminate an increase in the source potential of a transistor selected during writing or reading, this semiconductor device is equipped with: a variable-resistance type first switch having a first terminal and a second terminal; a variable-resistance type second switch having a third terminal and a fourth terminal, the third terminal being connected to the second terminal to form an intermediate node; first wiring connected to the first terminal; second wiring connected to the fourth terminal and, in a planar view, extending in a direction crossing the first wiring; a first selection transistor connected to the first wiring; a second selection transistor connected to the second wiring; a first well terminal connection line to which a well terminal of the first selection transistor is connected; and a second well terminal connection line to which a well terminal of the second selection transistor is connected.
    Type: Grant
    Filed: February 28, 2018
    Date of Patent: October 5, 2021
    Assignee: NANOBRIDGE SEMICONDUCTOR, INC.
    Inventors: Makoto Miyamura, Yukihide Tsuji, Toshitsugu Sakamoto, Ryusuke Nebashi, Ayuka Tada, Xu Bai
  • Publication number: 20210201996
    Abstract: Provided are a rewrite method for a variable resistance element that increases a rewrite count, and a non-volatile storage device using the variable resistance element. In the rewrite method for the variable resistance element, a variable resistance layer is disposed between a first electrode and a second electrode, and a write voltage is applied between the first electrode and the second electrode, thereby causing the resistance between the first electrode and the second electrode to reversibly change. After writing to the variable resistance element, the variable resistance element is read, the read current is measured, the measured read current is compared with a reference current, a condition of the writing is changed on the basis of the comparison results, and thereafter writing to the variable resistance element is performed again.
    Type: Application
    Filed: October 23, 2018
    Publication date: July 1, 2021
    Applicant: NEC Corporation
    Inventors: Toshitsugu SAKAMOTO, Naoki BANNO, Munehiro TADA, Yukihide TSUJI
  • Patent number: 11018671
    Abstract: A reconfigurable circuit includes: a first line; a first switch element disposed between the first line and a first power source line of first voltage; a second line; a second switch element disposed between the second line and a second power source line of second voltage which is different from the first voltage; and a resistive switch assembly disposed between the first line and the second line. The resistive switch assembly includes: a first non-volatile resistive switch; and a second non-volatile resistive switch whose first end is coupled to a first end of the first non-volatile resistive switch. The second end of the first non-volatile resistive switch is coupled to the first line, and the second end of the second non-volatile resistive switch is coupled to the second line.
    Type: Grant
    Filed: April 6, 2017
    Date of Patent: May 25, 2021
    Assignee: NEC CORPORATION
    Inventors: Xu Bai, Toshitsugu Sakamoto, Yukihide Tsuji, Makoto Miyamura, Ayuka Tada, Ryusuke Nebashi
  • Publication number: 20210133379
    Abstract: A design assistance system according to the present invention assists in designing a circuit to be mounted on a programmable logic integrated circuit including a resistance change element. The design assistance system includes: a memory; and at least one processor coupled to the memory. The processor performs operations. The operations includes: generating rewriting history information indicating a number (count) of changing times of a state of the resistance change element; calculating an abrasion cost of a switch included in the circuit, based on the rewriting history information; and carrying out wiring of the circuit, based on an evaluation function including the abrasion cost.
    Type: Application
    Filed: January 22, 2018
    Publication date: May 6, 2021
    Applicant: NEC Corporation
    Inventors: Ryusuke NEBASHI, Toshitsugu SAKAMOTO, Makoto MIYAMURA, Yukihide TSUJI, Ayuka TADA, Xu BAI
  • Patent number: 10979053
    Abstract: A logic integrated circuit includes a switch cell array. The switch cell array includes: a plurality of first wirings extending in a first direction; a plurality of second wirings extending in a second direction; a switch cell including a unit element including two serially connected resistance-changing elements, and a cell transistor to be connected to a shared terminal of the two resistance-changing elements; and a bit line to which the shared terminal is connected via the cell transistor. Two of the switch cells adjacent to each other in the first direction are each connected to the different first wiring and second wiring, and share the bit line, and a diffusion layer to which the bit line is connected.
    Type: Grant
    Filed: January 21, 2019
    Date of Patent: April 13, 2021
    Assignee: NANOBRIDGE SEMICONDUCTOR, INC.
    Inventors: Ryusuke Nebashi, Toshitsugu Sakamoto, Makoto Miyamura, Yukihide Tsuji, Ayuka Tada, Xu Bai
  • Publication number: 20210081591
    Abstract: A numerical information generating apparatus receives information of a programmable logic integrated circuit that includes a plurality of crossbar switches each including resistance change elements, calculates, for each of the plurality of crossbar switches, a base delay that is a delay in which influence of a load capacitance of other crossbar switch is excluded and a correction delay that is a delay caused by influence of a fanout of other crossbar switch, and further calculates a delay of each of the plurality of crossbar switches based on the base delay and the correction delay corresponding to each of the plurality of crossbar switches.
    Type: Application
    Filed: May 14, 2019
    Publication date: March 18, 2021
    Applicant: NEC Corporation
    Inventors: Ayuka TADA, Toshitsugu SAKAMOTO, Makoto MIYAMURA, Yukihide TSUJI, Ryusuke NEBASHI, Xu BAI
  • Publication number: 20210020238
    Abstract: A reconfigurable circuit includes: a complementary resistive switch including a first resistive switch, a second resistive switch and a selection transistor, wherein a first terminal of the first resistive switch is connected to a first terminal of the second resistive switch and connected to a first terminal of the selection transistor; a first current source having a first terminal connected to a second terminal of the first resistive switch and a second terminal connected to a ground voltage line; a second current source having a first terminal connected to a second terminal of the second resistive switch and a second terminal connected to the ground voltage line; and a resistor having a first terminal connected to a second terminal of the selection transistor and a second terminal connected to a power voltage line.
    Type: Application
    Filed: March 23, 2018
    Publication date: January 21, 2021
    Applicant: NEC Corporation
    Inventors: Xu BAI, Toshitsugu SAKAMOTO, Yukihide TSUJI, Makoto MIYAMURA, Ryusuke NEBASHI, Ayuka TADA
  • Patent number: 10879902
    Abstract: A reconfigurable circuit includes: a plurality of first lines; one or more second lines; a non-volatile resistive cell coupling one of the first lines with one of the second lines at each cross-point between the first lines and the second lines; and first switch elements including first terminals respectively coupled to the first lines, wherein each of the first switch elements is separately turned on or off in accordance with a control signal applied thereto.
    Type: Grant
    Filed: March 17, 2017
    Date of Patent: December 29, 2020
    Assignee: NEC CORPORATION
    Inventors: Xu Bai, Toshitsugu Sakamoto, Yukihide Tsuji, Makoto Miyamura, Ayuka Tada, Ryusuke Nebashi
  • Publication number: 20200381045
    Abstract: A semiconductor device which includes: a switch array in which a switch cell including a variable resistance switch is arranged at each location where a plurality of wires constituting a crossbar switch intersect; a first selection circuit that selects all of the variable resistance switches included in the switch array; a second selection circuit that selects any of the variable resistance switches included in the switch array; a reading circuit that reads a state of the variable resistance switch selected by any of the first selection circuit and the second selection circuit; and an error detection circuit that detects, based on a state of the variable resistance switch read by the reading circuit, an error in at least any of the variable resistance switches included in the switch array.
    Type: Application
    Filed: March 12, 2019
    Publication date: December 3, 2020
    Applicant: NEC Corporation
    Inventors: Toshitsugu SAKAMOTO, Ryusuke NEBASHI, Makoto MIYAMURA, Xu BAI, Yukihide TSUJI
  • Publication number: 20200380190
    Abstract: A design assistance system including: a logic synthesis unit that receives input of an operation description file of the programmable logic integrated circuit, logically synthesizes the inputted operation description file, and generates a net list by using logic elements included in the programmable logic integrated circuit; an arrangement wiring unit that generates resource information of the programmable logic integrated circuit, arranges the logic elements included in the net list on the basis of the generated resource information, and virtually generates a signal path by laying wires among the arranged logic elements; and a reliability control unit that generates configuration information of the programmable logic integrated circuit on the basis of at least two reliability modes, and outputs the generated configuration information.
    Type: Application
    Filed: November 21, 2018
    Publication date: December 3, 2020
    Applicant: NEC Corporation
    Inventors: Ryusuke NEBASHI, Toshitsugu SAKAMOTO, Makoto MIYAMURA, Yukihide TSUJI, Ayuka TADA, Xu BAI
  • Patent number: 10855283
    Abstract: A reconfigurable circuit comprising: crossbar switches; wires, each of which is coupled to one output port of one crossbar switch and input ports of the other crossbar switches; at least one inverter inserted on each wire for driving long-distance signal transfer, wherein one or less first inverter is inserted on the wire between two adjacent crossbar switches; one or two second inverters inserted between a crossbar switch input port and its connected wire.
    Type: Grant
    Filed: August 10, 2017
    Date of Patent: December 1, 2020
    Assignee: NEC CORPORATION
    Inventors: Xu Bai, Toshitsugu Sakamoto, Yukihide Tsuji, Makoto Miyamura, Ayuka Tada, Ryusuke Nebashi
  • Publication number: 20200350909
    Abstract: A semiconductor device includes: first wires which extend in a first direction; second wires extending in a second direction; a unit element which comprises two variable resistance elements connected in series, and has one end connected to a first wire and the other end connected to a second wire; a first control line for controlling the supply of a voltage to the first wire; a second control line for controlling the supply of a voltage to the second wire; and a cell circuit connected to an intermediate node between the two variable resistance elements and also connected to the first control line and the second control line. The cell circuit has: a cell transistor connected to an intermediate node writing driver which supplies a voltage to the intermediate node; and a cell control circuit which controls an electrical conduction state of the cell transistor.
    Type: Application
    Filed: February 8, 2019
    Publication date: November 5, 2020
    Applicant: NEC Corporation
    Inventors: Makoto MIYAMURA, Ryusuke NEBASHI, Toshitsugu SAKAMOTO, Yukihide TSUJI, Xu BAI, Ayuka TADA
  • Publication number: 20200336145
    Abstract: A logic integrated circuit includes a switch cell array. The switch cell array includes: a plurality of first wirings extending in a first direction; a plurality of second wirings extending in a second direction; a switch cell including a unit element including two serially connected resistance-changing elements, and a cell transistor to be connected to a shared terminal of the two resistance-changing elements; and a bit line to which the shared terminal is connected via the cell transistor. Two of the switch cells adjacent to each other in the first direction are each connected to the different first wiring and second wiring, and share the bit line, and a diffusion layer to which the bit line is connected.
    Type: Application
    Filed: January 21, 2019
    Publication date: October 22, 2020
    Applicant: NEC Corporation
    Inventors: Ryusuke NEBASHI, Toshitsugu SAKAMOTO, Makoto MIYAMURA, Yukihide TSUJI, Ayuka TADA, Xu BAI
  • Patent number: 10812076
    Abstract: A logic integrated circuit includes: a three-terminal resistance change switch including a first resistance change switch and a second resistance change switch connected in series; a reading circuit which reads first data based on a resistance state of the first resistance change switch and second data based on a resistance state of the second resistance change switch; and a first error detection circuit which compares the first data with the second data and issue an output based on a result of the comparison.
    Type: Grant
    Filed: January 16, 2017
    Date of Patent: October 20, 2020
    Assignee: NEC CORPORATION
    Inventors: Ryusuke Nebashi, Toshitsugu Sakamoto, Makoto Miyamura, Yukihide Tsuji, Ayuka Tada, Xu Bai
  • Publication number: 20200295764
    Abstract: A reconfigurable circuit includes: a first line; a first switch element disposed between the first line and a first power source line of first voltage; a second line; a second switch element disposed between the second line and a second power source line of second voltage which is different from the first voltage; and a resistive switch assembly disposed between the first line and the second line. The resistive switch assembly includes: a first non-volatile resistive switch; and a second non-volatile resistive switch whose first end is coupled to a first end of the first non-volatile resistive switch. The second end of the first non-volatile resistive switch is coupled to the first line, and the second end of the second non-volatile resistive switch is coupled to the second line.
    Type: Application
    Filed: April 6, 2017
    Publication date: September 17, 2020
    Applicant: NEC Corporation
    Inventors: Xu BAI, Toshitsugu SAKAMOTO, Yukihide TSUJI, Makoto MIYAMURA, Ayuka TADA, Ryusuke NEBASHI
  • Publication number: 20200295761
    Abstract: A reconfigurable circuit comprising: a first line; a first switch element disposed between the first line and a first power source line of first voltage; a second line; a second switch element disposed between the second line and a second power source line of second voltage which is different from the first voltage; and a resistive switch assembly disposed between the first line and the second line. The resistive switch assembly including a first non-volatile resistive switch, and a second non-volatile resistive switch whose first end is coupled to a first end of the first non-volatile resistive switch. The second end of the first non-volatile resistive switch is coupled to the first line, and the second end of the second non-volatile resistive switch is coupled to the second line.
    Type: Application
    Filed: May 13, 2016
    Publication date: September 17, 2020
    Applicant: NEC Corporation
    Inventors: Xu BAI, Toshitsugu SAKAMOTO, Yukihide TSUJI, Makoto MIYAMURA, Ayuka TADA, Ryusuke NEBASHI
  • Publication number: 20200266822
    Abstract: This logic integrated circuit has a plurality of first switch cells including variable resistance elements and a plurality of second switch cells including variable resistance elements. The logic integrated circuit comprises: a first output port and a second output port; the plurality of first switch cells for switching the electrical connections between a first wire and a third wire; the plurality of second switch cells for switching the electrical connections between a second wire and the third wire; a first control transistor which is connected to the first wire and which is for switching the electrical connections between the first wire and a first power line supplying power to the first wire; and a second control transistor which is connected to the second wire and which is for switching the electrical connections between the second wire and the first power line supplying power to the second wire.
    Type: Application
    Filed: September 14, 2018
    Publication date: August 20, 2020
    Applicant: NEC Corporation
    Inventors: Yukihide TSUJI, Toshitsugu SAKAMOTO, Makoto MIYAMURA, Ryusuke NEBASHI, Ayuka TADA, Xu BAI
  • Patent number: 10748614
    Abstract: In order to provide a highly reliable crossbar circuit that enables salvation of reversal of a resistive state of a variable resistance element, the semiconductor device has a configuration obtained by parallelly arranging two unit elements, each including variable-resistance two-terminal elements connected in series, the semiconductor device being provided with: a unit element group being connected to a first wiring and a second wiring; a first programming driver that changes, via the first wiring, a resistive state of the two-terminal element constituting the unit element group; a first selection transistor being connected to the first wiring and the first programming driver; a second programming driver that changes, via the second wiring, a resistive state of the two-terminal element constituting the unit element group; and a second selection transistor being connected to the second wiring and the second programming driver.
    Type: Grant
    Filed: September 11, 2017
    Date of Patent: August 18, 2020
    Assignee: NEC CORPORATION
    Inventors: Makoto Miyamura, Ryusuke Nebashi, Toshitsugu Sakamoto, Yukihide Tsuji, Xu Bai, Ayuka Tada
  • Publication number: 20200251496
    Abstract: A programmable integrated circuit includes: a crossbar switch constituted of a plurality of first wires arranged in a first direction, a plurality of second wires arranged in a second direction intersecting the first direction, and resistance change type elements connecting the first wires and the second wires; an output buffer group constituted of at least two output buffers operating with different drive powers; and a logic circuit group constituted of at least one logic circuit connected to an output of the second wire. The output buffers in the output buffer group is connected to an input of any one of a plurality of the first wires.
    Type: Application
    Filed: September 14, 2018
    Publication date: August 6, 2020
    Applicant: NEC Corporation
    Inventors: Makoto MIYAMURA, Toshitsugu SAKAMOTO, Yukihide TSUJI, Ryusuke NEBASHI, Ayuka TADA, Xu BAI