Patents by Inventor Koki Tsutsumida

Koki Tsutsumida 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: 9291671
    Abstract: There is provided a semiconductor integrated circuit in which a ring oscillator is formed by a variable delay circuit to cause the ring oscillator to oscillate (S2) at the test operation of the variable delay circuit and it is determined whether the variable delay circuit is normal or abnormal depending on whether the ring oscillator satisfies a predetermined monotonic increase condition (S6) and a predetermined linearity condition (S7).
    Type: Grant
    Filed: November 19, 2013
    Date of Patent: March 22, 2016
    Assignee: Hitachi, Ltd.
    Inventors: Yasuyoshi Sunaga, Hideki Sakakibara, Yuko Ito, Tomoji Nakamura, Atsushi Hazeyama, Kozaburo Kurita, Koki Tsutsumida
  • Publication number: 20140070863
    Abstract: There is provided a semiconductor integrated circuit in which a ring oscillator is formed by a variable delay circuit to cause the ring oscillator to oscillate (S2) at the test operation of the variable delay circuit and it is determined whether the variable delay circuit is normal or abnormal depending on whether the ring oscillator satisfies a predetermined monotonic increase condition (S6) and a predetermined linearity condition (S7).
    Type: Application
    Filed: November 19, 2013
    Publication date: March 13, 2014
    Applicant: Hitachi, Ltd.
    Inventors: Yasuyoshi Sunaga, Hideki Sakakibara, Yuko Ito, Tomoji Nakamura, Atsushi Hazeyama, Kozaburo Kurita, Koki Tsutsumida
  • Patent number: 8618823
    Abstract: A semiconductor device is designed to facilitate analyzing a position and a cause of the failure of an integrated circuit adopting a polyphase clock. To this end, the semiconductor device is provided with an error detecting unit that detects that a problem of the operation occurs in the integrated circuit, a clock state holding unit that holds the information of phases in a predetermined term of a two- or more-phase clock and an output unit that outputs the information of the phases in the predetermined term of the two- or more-phase clock when the error detecting unit detects that the problem of the operation occurs in the integrated circuit.
    Type: Grant
    Filed: January 13, 2011
    Date of Patent: December 31, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Kenichi Tada, Koki Tsutsumida, Masatoshi Kawashima, Hideki Hayashi, Tsutomu Sato, Koichi Sugimoto
  • Patent number: 8086889
    Abstract: A scan chain group structure in which a group of scan chains formed for each clock tree system in an LSI is subjected to a reconnection process so that the scan chain group is not present across a plurality of clock distribution regions obtained by dividing the clock-supplied region of the clock tree of one system and that the connection distance thereof in the distribution region becomes short, a test clock input mechanism in which test clocks to be input to the distribution regions are independent sub-clock phases, and an on/off mechanism of the clocks to be input to the distribution regions are realized. Further, the scan-in/out and scan test performed at the same time are limited in one region or between single regions, and tests in all regions and between all regions are carried out by a plurality of times of test steps.
    Type: Grant
    Filed: October 23, 2008
    Date of Patent: December 27, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Yuichi Ito, Yasuhiro Fujimura, Koki Tsutsumida, Shigeru Nakahara
  • Publication number: 20110204908
    Abstract: A semiconductor device is designed to facilitate analyzing a position and a cause of the failure of an integrated circuit adopting a polyphase clock. To this end, the semiconductor device is provided with an error detecting unit that detects that a problem of the operation occurs in the integrated circuit, a clock state holding unit that holds the information of phases in a predetermined term of a two- or more-phase clock and an output unit that outputs the information of the phases in the predetermined term of the two- or more-phase clock when the error detecting unit detects that the problem of the operation occurs in the integrated circuit.
    Type: Application
    Filed: January 13, 2011
    Publication date: August 25, 2011
    Inventors: Kenichi Tada, Koki Tsutsumida, Masatoshi Kawashima, Hideki Hayashi, Tsutomu Sato, Koichi Sugimoto
  • Publication number: 20110074385
    Abstract: There is provided a semiconductor integrated circuit in which a ring oscillator is formed by a variable delay circuit to cause the ring oscillator to oscillate (S2) at the test operation of the variable delay circuit and it is determined whether the variable delay circuit is normal or abnormal depending on whether the ring oscillator satisfies a predetermined monotonic increase condition (S6) and a predetermined linearity condition (S7).
    Type: Application
    Filed: August 3, 2010
    Publication date: March 31, 2011
    Inventors: Yasuyoshi Sunaga, Hideki Sakakibara, Yuko Ito, Tomoji Nakamura, Atsushi Hazeyama, Kozaburo Kurita, Koki Tsutsumida
  • Publication number: 20100169727
    Abstract: There is provided a technique for avoiding test-time IR drops which occur when the frequency that adjacent FFs in a scan chain have different logical values increases. An expected value derivation module derives the expected value of each FF by calculating probability propagation or performing logic simulation. A grouping module groups each FF subject to a test into a number of groups by referring to the obtained expected value. A scan chain configuration module pairs two groups whose logical-value-1 intake frequencies are opposite to each other, performs logic reversal on one group, and configures one scan chain.
    Type: Application
    Filed: December 26, 2009
    Publication date: July 1, 2010
    Inventors: Daisuke ITO, Hiroki Yamanaka, Koki Tsutsumida
  • Publication number: 20090113230
    Abstract: A scan chain group structure in which a group of scan chains formed for each clock tree system in an LSI is subjected to a reconnection process so that the scan chain group is not present across a plurality of clock distribution regions obtained by dividing the clock-supplied region of the clock tree of one system and that the connection distance thereof in the distribution region becomes short, a test clock input mechanism in which test clocks to be input to the distribution regions are independent sub-clock phases, and an on/off mechanism of the clocks to be input to the distribution regions are realized. Further, the scan-in/out and scan test performed at the same time are limited in one region or between single regions, and tests in all regions and between all regions are carried out by a plurality of times of test steps.
    Type: Application
    Filed: October 23, 2008
    Publication date: April 30, 2009
    Inventors: Yuichi Ito, Yasuhiro Fujimura, Koki Tsutsumida, Shigeru Nakahara