Patents by Inventor Noboru Sakimura
Noboru Sakimura 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).
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Patent number: 9478309Abstract: Provided is a magnetic domain wall displacement memory cell, including a recording layer including a magnetic film, the recording layer including: a magnetization reversal region in which magnetization is reversible; and first and second magnetization fixed regions that supply a spin-polarized electron to the magnetization reversal region. The magnetic domain wall displacement memory cell is configured so that a first region in which magnetization reversal occurs due to a first current flowing in a direction parallel to a film surface of the recording layer and a first magnetic field component in the direction parallel to the film surface of the recording layer is formed, and a second region in which no magnetization reversal occurs is formed.Type: GrantFiled: September 13, 2013Date of Patent: October 25, 2016Assignees: NEC CORPORATION, TOHOKU UNIVERSITYInventors: Ryusuke Nebashi, Noboru Sakimura, Tadahiko Sugibayashi, Yukihide Tsuji, Ayuka Tada, Hiroaki Honjou, Hideo Ohno
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Publication number: 20160300614Abstract: In order to provide a technique for reducing an area of a content addressable memory cell and suppressing a leak current in a content addressable memory which calculates similarity, a content addressable memory cell of the present invention, comprising: a resistance network which includes plural current paths, a logic circuit for selecting a current path in response to input data, and a variable-resistance-type non-volatile memory element that is arranged on at least one current path and stores data and whose resistance value is changed according to a result of logical calculation based on the input data and the stored data; and a charge/discharge circuit which is connected with the resistance network and a match line and whose delay time from inputting a signal through the match line until outputting the signal is changed according to the result of logical calculation based on the input data and the stored data.Type: ApplicationFiled: June 17, 2014Publication date: October 13, 2016Applicant: NEC CORPORATIONInventors: Ryusuke NEBASHI, Noboru SAKIMURA, Tadahiko SUGIBAYSHI
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Patent number: 9299435Abstract: Provided is a nonvolatile content addressable memory. Each word circuit includes a plurality of segments having an order relation. Each of the segments includes one or more memory cells. Each of the memory cells includes a nonvolatile storage element. Each of the segments includes a power switch for turning on/off a power of a memory cell of the segment. During stand-by, all the power switches are turned off, and, in search operation, the power switch is turned on as necessary for each of the segments.Type: GrantFiled: August 1, 2013Date of Patent: March 29, 2016Assignees: NEC CORPORATION, TOHOKU UNIVERSITYInventors: Noboru Sakimura, Ryusuke Nebashi, Tadahiko Sugibayashi, Shoun Matsunaga, Takahiro Hanyu, Hideo Ohno
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Publication number: 20160077563Abstract: A semiconductor integrated circuit (100) comprising: a plurality of processing circuits (11, 12, 13) each including a notification units for outputting a notification signal according to the processing state of the own processing circuit; a plurality of power supply switch units (SW1, SW2, SW3) for switching the connection states between the respective processing circuits and a power supply source; a power supply switch control circuit which is connected with the notification means (111, 121, 131), stores power supply control information (101) including a plurality of connection statuses, and controls the connection states on the basis of the notification signals and the power supply control information; and a data bus (BS) and the like connecting each of the processing circuits and the power supply switch control circuit, wherein: at least two or more of the plurality of processing circuits update the power supply control information via the data bus and the like before outputting a notification signal; andType: ApplicationFiled: January 7, 2014Publication date: March 17, 2016Applicant: NEC CORPORATIONInventors: Yukihide TSUJI, Noboru SAKIMURA, Ryusuke NEBASHI, Ayuka TADA
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Patent number: 9135988Abstract: A semiconductor device includes non-volatile registers, each including a holding circuit to hold data in a volatile manner and a non-volatile element. An address is allocated to each of the non-volatile registers. A non-volatile register control circuit performs control such that, in response to a write instruction, data held in the holding circuit is written to the non-volatile element in the non-volatile register having the address specified by the instruction and in response to a load instruction, data held in the non-volatile element is held in the holding circuit in the non-volatile register having the address specified by the instruction.Type: GrantFiled: September 7, 2012Date of Patent: September 15, 2015Assignee: NEC CORPORATIONInventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Ayuka Tada
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Publication number: 20150248939Abstract: Provided is a magnetic domain wall displacement memory cell, including a recording layer including a magnetic film, the recording layer including: a magnetization reversal region in which magnetization is reversible; and first and second magnetization fixed regions that supply a spin-polarized electron to the magnetization reversal region. The magnetic domain wall displacement memory cell is configured so that a first region in which magnetization reversal occurs due to a first current flowing in a direction parallel to a film surface of the recording layer and a first magnetic field component in the direction parallel to the film surface of the recording layer is formed, and a second region in which no magnetization reversal occurs is formed.Type: ApplicationFiled: September 13, 2013Publication date: September 3, 2015Applicants: NEC Corporation, Tohoku UniversityInventors: Ryusuke Nebashi, Noboru Sakimura, Tadahiko Sugibayashi, Yukihide Tsuji, Ayuka Tada, Hiroaki Honjou, Hideo Ohno
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Publication number: 20150235703Abstract: Provided is a nonvolatile content addressable memory. Each word circuit includes a plurality of segments having an order relation. Each of the segments includes one or more memory cells. Each of the memory cells includes a nonvolatile storage element. Each of the segments includes a power switch for turning on/off a power of a memory cell of the segment. During stand-by, all the power switches are turned off, and, in search operation, the power switch is turned on as necessary for each of the segments.Type: ApplicationFiled: August 1, 2013Publication date: August 20, 2015Applicants: TOHOKU UNIVERSITY, NEC CORPORATIONInventors: Noboru Sakimura, Ryusuke Nebashi, Tadahiko Sugibayashi, Shoun Matsunaga, Takahiro Hanyu, Hideo Ohno
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Patent number: 9100013Abstract: Provided is a nonvolatile resistor network assembly characterized by that: it comprises a first and a second resistor network which are each composed of a plurality of nonvolatile resistive elements connected together; it also comprises a write means for writing into the first and second resistor networks; and writing into the first and second resistor networks is performed by the use of the write means in a manner to make total resistances of respectively the first and second resistor networks different from each other. Further provided is a nonvolatile logic gate which performs logical operation using stored data determined by the total resistances of the respective nonvolatile resistor networks.Type: GrantFiled: September 6, 2012Date of Patent: August 4, 2015Assignee: NEC CORPORATIONInventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Tadahiko Sugibayashi
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Publication number: 20150138877Abstract: A nonvolatile logic gate device is configured to include a resistive network of a memory structure in which at least three nonvolatile resistive elements are connected, a reference resistive network as a reference resistance providing a tolerance of the memory structure to a resistance value of the resistive network of the memory structure, a writing part operable to selectively write or rewrite a value of each of the nonvolatile resistive elements in the resistive network into a maximum or a minimum corresponding to a logical value to be read when data are stored into the resistive network, and a logic circuit structure operable to use, as a logical value of the memory structure, a value obtained by comparison between the resistance value of the resistive network and the resistance value of the reference resistive network.Type: ApplicationFiled: May 15, 2013Publication date: May 21, 2015Applicants: TOHOKU UNIVERSITY, NEC CORPORATIONInventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Ayuka Tada, Tadahiko Sugibayashi, Takahiro Hanyu, Tetsuo Endoh, Hideo Ohno
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Publication number: 20150048680Abstract: A semiconductor device includes a current control unit whose conductance is variable and a control unit configured to control the conductance of the current control unit. The current control unit is connected to a direct current power source in parallel with a load for the direct current power source, through a capacitor. The control unit sets the current control unit to a first conductance when the direct current power source and the load are not in a conduction state, and sets the current control unit to a second conductance larger than the first conductance when the direct current power source and the load are in the conduction state.Type: ApplicationFiled: March 28, 2013Publication date: February 19, 2015Inventors: Makoto Miyamura, Noboru Sakimura, Ryusuke Nebashi, Yukihide Tsuji, Tadahiko Sugibayashi
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Publication number: 20150042376Abstract: Provided is a nonvolatile resistor network assembly characterized by that: it comprises a first and a second resistor network which are each composed of a plurality of nonvolatile resistive elements connected together; it also comprises a write means for writing into the first and second resistor networks; and writing into the first and second resistor networks is performed by the use of the write means in a manner to make total resistances of respectively the first and second resistor networks different from each other. Further provided is a nonvolatile logic gate which performs logical operation using stored data determined by the total resistances of the respective nonvolatile resistor networks.Type: ApplicationFiled: September 6, 2012Publication date: February 12, 2015Applicant: NEC CORPORATIONInventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Tadahiko Sugibayashi
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Patent number: 8902644Abstract: A magnetoresistive element 10 having a memory cell 100 according to the present invention contains a first lower terminal n1 and a second lower terminal n2 respectively connected to both ends of a conductive layer 3 whose longitudinal direction is different from the column direction (X direction). Further, the gates of the first transistors M1 respectively included in two memory cells among the plurality of memory cells 100 and adjacent to each other in a row direction (Y direction) are commonly connected to a first word line 14. As a result, without increase of the cell area, it becomes possible to reserve a margin in the dimension of the cell structure or in the process for MRMA.Type: GrantFiled: December 6, 2011Date of Patent: December 2, 2014Assignee: NEC CorporationInventors: Noboru Sakimura, Ryusuke Nebashi, Tadahiko Sugibayashi
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Patent number: 8872542Abstract: A semiconductor device comprises: reconfigurable logic circuit that includes plurality of resistance change elements; logical configuration of the reconfigurable logic circuit being decided depending on whether each of plurality of resistance change elements is in first resistance state or in second resistance state whose resistance value is lower than resistance value of first resistance state; resistance value monitor circuit that includes resistance change element pre-programmed to the first resistance state; the resistance value monitor circuit detecting whether or not pre-programmed resistance change element retains the first resistance state; and controller that, in case it is detected that resistance change element provided in resistance value monitor circuit doe not retain first resistance state, applies voltage used in programming from second resistance state to first resistance state to resistance change element retaining first resistance states, out of plurality of resistance change elements providType: GrantFiled: September 21, 2011Date of Patent: October 28, 2014Assignee: NEC CorporationInventors: Noboru Sakimura, Munehiro Tada, Toshitsugu Sakamoto, Ryusuke Nebashi
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Publication number: 20140313843Abstract: A semiconductor integrated circuit includes a plurality of first non-volatile registers including a retention circuit that retains volatile data and one or more non-volatile elements capable of retaining non-volatile data, and a second non-volatile register that retains a load enable bit that decides in which one of the plurality of first non-volatile registers data is loaded. The semiconductor integrated circuit also includes a non-volatile register control circuit that, when supply power is delivered from outside, loads to the retention circuit data retained by the non-volatile element(s) contained in the first non-volatile register specified by the load enable bit loaded from the second non-volatile register (FIG. 1).Type: ApplicationFiled: November 20, 2012Publication date: October 23, 2014Applicant: NEC CorporationInventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Ayuka Tada
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Publication number: 20140233304Abstract: A semiconductor device includes non-volatile registers, each including a holding circuit to hold data in a volatile manner and a non-volatile element. An address is allocated to each of the non-volatile registers. A non-volatile register control circuit performs control such that, in response to a write instruction, data held in the holding circuit is written to the non-volatile element in the non-volatile register having the address specified by the instruction and in response to a load instruction, data held in the non-volatile element is held in the holding circuit in the non-volatile register having the address specified by the instruction.Type: ApplicationFiled: September 7, 2012Publication date: August 21, 2014Applicant: NEC CorporationInventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Ayuka Tada
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Patent number: 8737119Abstract: A magnetic memory cell 1 is provided with a magnetic recording layer 10 which is a ferromagnetic layer and a pinned layer 30 connected with the magnetic recording layer 10 through a non-magnetic layer 20. The magnetic recording layer 10 has a magnetization inversion region 13, a first magnetization fixed region 11 and a second magnetization fixed region 12. The magnetization inversion region 13 has a magnetization whose orientation is invertible and overlaps the pinned layer 30. The first magnetization fixed region 11 is connected with a first boundary B1 in the magnetization inversion region 13 and a magnetization orientation is fixed on a first direction. The second magnetization fixed region 12 is connected with a second boundary B2 in magnetization inversion region 13 and a magnetization orientation is fixed on a second direction. The first direction and the second direction are opposite to each other.Type: GrantFiled: March 29, 2012Date of Patent: May 27, 2014Assignee: NEC CorporationInventors: Takeshi Honda, Noboru Sakimura, Tadahiko Sugibayashi, Hideaki Numata, Norikazu Ohshima
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Patent number: 8693238Abstract: An MRAM of a spin transfer type is provided with a memory cell 10 and a word driver 30. The memory cell 10 has a magnetic resistance element 1 and a selection transistor TR having one of source/drain electrodes which is connected with one end of the magnetic resistance element 1. The word driver 30 drives a word line WL connected with a gate electrode of the selection transistor TR. The word driver 30 changes a drive voltage of the word line WL according to the write data DW to be written in the magnetic resistance element 1.Type: GrantFiled: July 13, 2007Date of Patent: April 8, 2014Assignee: NEC CorporationInventors: Noboru Sakimura, Takeshi Honda, Tadahiko Sugibayashi
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Patent number: 8510633Abstract: Provided is an operation method which can be applied to a PRAM, an ReRAM, and a solid electrolyte memory which stores error correction codes, each of which comprises of symbols, each of which comprises bits, and which codes allow error correction in units of symbols. In the operation method, the respective symbols are read by using different reference cells 12. When a correctable error is detected in read data from data cells forming the error correction codes and corresponding to an input address, a data in a data cell corresponding to the error bit is corrected for a first error symbol of an one bit error pattern, and data in a reference cell that is used to read the second error symbol are corrected for a second error symbol related to a multi-bit error pattern.Type: GrantFiled: April 14, 2008Date of Patent: August 13, 2013Assignee: NEC CorporationInventors: Noboru Sakimura, Tadahiko Sugibayashi, Ryusuke Nebashi
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Patent number: 8503222Abstract: A non-volatile logic circuit includes an input section, a control section and an output section. The input section has perpendicular magnetic anisotropy and has a ferromagnetic layer whose magnetization state is changeable. The control section includes a ferromagnetic layer. The output section is provided in a neighborhood of the input section and the control section and includes a magnetic tunnel junction element whose magnetization state is changeable. The magnetization state of the input section is changed based on the magnetization state. A magnetization state of the magnetic tunnel junction element of the output section which state is changed based on the magnetization state of the ferromagnetic material of the control section and the magnetization state of the ferromagnetic material of the input section.Type: GrantFiled: January 21, 2010Date of Patent: August 6, 2013Assignee: NEC CorporationInventors: Tetsuhiro Suzuki, Shunsuke Fukami, Kiyokazu Nagahara, Nobuyuki Ishiwata, Tadahiko Sugibayashi, Noboru Sakimura, Ryusuke Nebashi
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Publication number: 20130182501Abstract: A magnetoresistive element 10 having a memory cell 100 according to the present invention contains a first lower terminal n1 and a second lower terminal n2 respectively connected to both ends of a conductive layer 3 whose longitudinal direction is different from the column direction (X direction). Further, the gates of the first transistors M1 respectively included in two memory cells among the plurality of memory cells 100 and adjacent to each other in a row direction (Y direction) are commonly connected to a first word line 14. As a result, without increase of the cell area, it becomes possible to reserve a margin in the dimension of the cell structure or in the process for MRMA.Type: ApplicationFiled: December 6, 2011Publication date: July 18, 2013Inventors: Noboru Sakimura, Ryusuke Nebashi, Tadahiko Sugibayashi