Patents by Inventor Shigetoshi Wakayama

Shigetoshi Wakayama 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: 8468481
    Abstract: A design support program executed by a computer includes operations of: locating at least one via hole for coupling target wiring in a first layer in circuit information to wiring in a second layer being different form the first layer; calculating an area of the target wiring based on a length and a width of the target wiring; setting a division condition based on the area and a number of the via hole; dividing the target wiring into divided wirings at a position other than a position where the via hole is provided based on the division condition; generating connection information indicating a connection relationship between the divided wirings and limitation information for coupling the divided wirings via a wiring in a third layer being different from the first layer; and outputting the connection information, the limitation information and circuit information obtained after dividing.
    Type: Grant
    Filed: July 23, 2010
    Date of Patent: June 18, 2013
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Toshiharu Nozawa, Shigetoshi Wakayama, Mitsuaki Igeta
  • Patent number: 8065553
    Abstract: A semiconductor integrated circuit device has a command decoder for issuing a control command in accordance with a supplied control signal, a DRAM core, and a timing adjusting circuit for supplying the control command, set active for a predetermined period, as a DRAM control signal to the DRAM core. The timing adjusting circuit generates n different clocks that are respectively shifted in phase with respect to a supplied reference clock, and generates the DRAM control signal by setting the control command active in a prescribed operation cycle for only a period starting at a first predetermined clock pulse of a first clock of the n clocks and ending at a second predetermined clock pulse of a second clock of the n clocks. In this way, timing design with relatively high accuracy of adjustment can be done in a short period.
    Type: Grant
    Filed: January 23, 2009
    Date of Patent: November 22, 2011
    Assignee: Fujitsu Limited
    Inventors: Hirotaka Tamura, Hisakatsu Yamaguchi, Shigetoshi Wakayama, Kohtaroh Gotoh, Junji Ogawa
  • Publication number: 20110041113
    Abstract: A design support program executed by a computer includes operations of: locating at least one via hole for coupling target wiring in a first layer in circuit information to wiring in a second layer being different form the first layer; calculating an area of the target wiring based on a length and a width of the target wiring; setting a division condition based on the area and a number of the via hole; dividing the target wiring into divided wirings at a position other than a position where the via hole is provided based on the division condition; generating connection information indicating a connection relationship between the divided wirings and limitation information for coupling the divided wirings via a wiring in a third layer being different from the first layer; and outputting the connection information, the limitation information and circuit information obtained after dividing.
    Type: Application
    Filed: July 23, 2010
    Publication date: February 17, 2011
    Applicant: FUJITSU SEMICONDUCTOR LIMITED
    Inventors: Toshiharu NOZAWA, Shigetoshi Wakayama, Mitsuaki Igeta
  • Patent number: 7642624
    Abstract: A multilayer interconnection structure of a semiconductor device includes a first guard ring extending continuously along a periphery of a substrate and a second guard ring extending continuously in the multilayer interconnection structure along the periphery so as to be encircled by the first guard ring and so as to encircle an interconnection pattern inside the multilayer interconnection structure, wherein the first and second guard rings are connected with each other mechanically and continuously by a bridging conductor pattern extending continuously in a band form along a region including the first and second guard rings when viewed in the direction perpendicular to the substrate.
    Type: Grant
    Filed: July 6, 2007
    Date of Patent: January 5, 2010
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Shigetoshi Wakayama, Matsuaki Kai, Hiroyuki Kato, Masato Suga
  • Publication number: 20090195281
    Abstract: A semiconductor integrated circuit device has a command decoder for issuing a control command in accordance with a supplied control signal, a DRAM core, and a timing adjusting circuit for supplying the control command, set active for a predetermined period, as a DRAM control signal to the DRAM core. The timing adjusting circuit generates n different clocks that are respectively shifted in phase with respect to a supplied reference clock, and generates the DRAM control signal by setting the control command active in a prescribed operation cycle for only a period starting at a first predetermined clock pulse of a first clock of the n clocks and ending at a second predetermined clock pulse of a second clock of the n clocks. In this way, timing design with relatively high accuracy of adjustment can be done in a short period.
    Type: Application
    Filed: January 23, 2009
    Publication date: August 6, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Hirotaka Tamura, Hisakatsu Yamaguchi, Shigetoshi Wakayama, Kohtaroh Gotoh, Junji Ogawa
  • Patent number: 7496781
    Abstract: A semiconductor integrated circuit device has a command decoder for issuing a control command in accordance with a supplied control signal, a DRAM core, and a timing adjusting circuit for supplying the control command, set active for a predetermined period, as a DRAM control signal to the DRAM core. The timing adjusting circuit generates n different clocks that are respectively shifted in phase with respect to a supplied reference clock, and generates the DRAM control signal by setting the control command active in a prescribed operation cycle for only a period starting at a first predetermined clock pulse of a first clock of the n clocks and ending at a second predetermined clock pulse of a second clock of the n clocks. In this way, timing design with relatively high accuracy of adjustment can be done in a short period.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: February 24, 2009
    Assignee: Fujitsu, Ltd.
    Inventors: Hirotaka Tamura, Hisakatsu Yamaguchi, Shigetoshi Wakayama, Kohtaroh Gotoh, Junji Ogawa
  • Patent number: 7342434
    Abstract: A capacitor has a MOS gate structure in which a gate insulating film is held between a gate terminal and a ground terminal as a dielectric. A switch unit is connected between the gate terminal and a power supply. The ground terminal is connected to a ground. A switch control circuit that switches a state of the switch unit between a conductive state and a nonconductive state is provided. A predetermined voltage and a voltage of the gate terminal are input to a non-inverting input terminal and an inverting input terminal of the switch control circuit, respectively. The switch unit is conductive when the voltage of the gate terminal is higher than the predetermined voltage, and nonconductive when the voltage of the gate terminal is lower than the predetermined voltage.
    Type: Grant
    Filed: January 26, 2005
    Date of Patent: March 11, 2008
    Assignee: Fujitsu Limited
    Inventors: Shigetoshi Wakayama, Mutsuaki Kai
  • Publication number: 20070257371
    Abstract: A multilayer interconnection structure of a semiconductor device includes a first guard ring extending continuously along a periphery of a substrate and a second guard ring extending continuously in the multilayer interconnection structure along the periphery so as to be encircled by the first guard ring and so as to encircle an interconnection pattern inside the multilayer interconnection structure, wherein the first and second guard rings are connected with each other mechanically and continuously by a bridging conductor pattern extending continuously in a band form along a region including the first and second guard rings when viewed in the direction perpendicular to the substrate.
    Type: Application
    Filed: July 6, 2007
    Publication date: November 8, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Shigetoshi Wakayama, Mutsuaki Kai, Hiroyuki Kato, Masato Suga
  • Patent number: 7256474
    Abstract: A multilayer interconnection structure of a semiconductor device includes a first guard ring extending continuously along a periphery of a substrate and a second guard ring extending continuously in the multilayer interconnection structure along the periphery so as to be encircled by the first guard ring and so as to encircle an interconnection pattern inside the multilayer interconnection structure, wherein the first and second guard rings are connected with each other mechanically and continuously by a bridging conductor pattern extending continuously in a band form along a region including the first and second guard rings when viewed in the direction perpendicular to the substrate.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: August 14, 2007
    Assignee: Fujitsu Limited
    Inventors: Shigetoshi Wakayama, Mutsuaki Kai, Hiroyuki Kato, Masato Suga
  • Patent number: 7106108
    Abstract: An input circuit writes an expected value to one end of an evaluation wiring. A latch circuit latches a logic level of the other end of the evaluation wiring. A first switch circuit connects an output of the input circuit to the input of the latch circuit. A second switch circuit connects the output of the input circuit to the one end of the evaluation wiring. A third switch circuit connects the other end of the evaluation wiring to the input of the latch circuit. By turning on, off, and off the first to third switch circuits, respectively, the output of the input circuit is directly connected to only the input of the latch circuit. In this state, the input circuit writes an expected value, and a logic level is read from the latch circuit. Accordingly, failure of the evaluation wiring can be easily discriminated from other failure.
    Type: Grant
    Filed: June 18, 2004
    Date of Patent: September 12, 2006
    Assignee: Fujitsu Limited
    Inventors: Mitsuaki Igeta, Shigetoshi Wakayama, Seiji Endou
  • Patent number: 7096375
    Abstract: A circuit for data transfer includes a first buffer operating at a first clock frequency, a plurality of second buffers operating at a second clock frequency, and a selector circuit which receives data at the first clock frequency, and supplies the data to a selected one of the first buffer and the second buffers.
    Type: Grant
    Filed: November 19, 2002
    Date of Patent: August 22, 2006
    Assignee: Fujitsu Limited
    Inventors: Shigetoshi Wakayama, Hiroshi Okano, Yoshio Hirose
  • Publication number: 20060061409
    Abstract: A capacitor has a MOS gate structure in which a gate insulating film is held between a gate terminal and a ground terminal as a dielectric. A switch unit is connected between the gate terminal and a power supply. The ground terminal is connected to a ground. A switch control circuit that switches a state of the switch unit between a conductive state and a nonconductive state is provided. A predetermined voltage and a voltage of the gate terminal are input to a non-inverting input terminal and an inverting input terminal of the switch control circuit, respectively. The switch unit is conductive when the voltage of the gate terminal is higher than the predetermined voltage, and nonconductive when the voltage of the gate terminal is lower than the predetermined voltage.
    Type: Application
    Filed: January 26, 2005
    Publication date: March 23, 2006
    Inventors: Shigetoshi Wakayama, Mutsuaki Kai
  • Publication number: 20050144546
    Abstract: An input circuit writes an expected value to one end of an evaluation wiring. A latch circuit latches a logic level of the other end of the evaluation wiring. A first switch circuit connects an output of the input circuit to the input of the latch circuit. A second switch circuit connects the output of the input circuit to the one end of the evaluation wiring. A third switch circuit connects the other end of the evaluation wiring to the input of the latch circuit. By turning on, off, and off the first to third switch circuits, respectively, the output of the input circuit is directly connected to only the input of the latch circuit. In this state, the input circuit writes an expected value, and a logic level is read from the latch circuit. Accordingly, failure of the evaluation wiring can be easily discriminated from other failure.
    Type: Application
    Filed: June 18, 2004
    Publication date: June 30, 2005
    Inventors: Mitsuaki Igeta, Shigetoshi Wakayama, Seiji Endou
  • Publication number: 20040188843
    Abstract: A multilayer interconnection structure of a semiconductor device includes a first guard ring extending continuously along a periphery of a substrate and a second guard ring extending continuously in the multilayer interconnection structure along the periphery so as to be encircled by the first guard ring and so as to encircle an interconnection pattern inside the multilayer interconnection structure, wherein the first and second guard rings are connected with each other mechanically and continuously by a bridging conductor pattern extending continuously in a band form along a region including the first and second guard rings when viewed in the direction perpendicular to the substrate.
    Type: Application
    Filed: February 13, 2004
    Publication date: September 30, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Shigetoshi Wakayama, Mutsuaki Kai, Hiroyuki Kato, Masato Suga
  • Publication number: 20030112051
    Abstract: A circuit for data transfer includes a first buffer operating at a first clock frequency, a plurality of second buffers operating at a second clock frequency, and a selector circuit which receives data at the first clock frequency, and supplies the data to a selected one of the first buffer and the second buffers.
    Type: Application
    Filed: November 19, 2002
    Publication date: June 19, 2003
    Inventors: Shigetoshi Wakayama, Hiroshi Okano, Yoshio Hirose
  • Patent number: 6493394
    Abstract: A signal transmission system has a response time of a signal transmission line which is set approximately equal to or longer than the length of a transmitted symbol. More specifically, terminal resistance is set larger than the characteristic impedance of the signal transmission line, driver output resistance is set to a large value, or a damping resistor is provided in series with the signal transmission line. With this configuration, signal power can be reduced drastically.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: December 10, 2002
    Assignee: Fujitsu Limited
    Inventors: Hirotaka Tamura, Miyoshi Saito, Kohtaroh Gotoh, Shigetoshi Wakayama, Junji Ogawa, Hisakatsu Araki, Tsz-shing Cheung
  • Patent number: 6484268
    Abstract: A semiconductor integrated circuit device has a command decoder for issuing a control command in accordance with a supplied control signal, a DRAM core, and a timing adjusting circuit for supplying the control command, set active for a predetermined period, as a DRAM control signal to the DRAM core. The timing adjusting circuit generates n different clocks that are respectively shifted in phase with respect to a supplied reference clock, and generates the DRAM control signal by setting the control command active in a prescribed operation cycle for only a period starting at a first predetermined clock pulse of a first clock of the n clocks and ending at a second predetermined clock pulse of a second clock of the n clocks. In this way, timing design with relatively high accuracy of adjustment can be done in a short period.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: November 19, 2002
    Assignee: Fujitsu Limited
    Inventors: Hirotaka Tamura, Hisakatsu Araki, Shigetoshi Wakayama, Kohtaroh Gotoh, Junji Ogawa
  • Publication number: 20020080883
    Abstract: A signal transmission system has a response time of a signal transmission line which is set approximately equal to or longer than the length of a transmitted symbol. More specifically, terminal resistance is set larger than the characteristic impedance of the signal transmission line, driver output resistance is set to a large value, or a damping resistor is provided in series with the signal transmission line. With this configuration, signal power can be reduced drastically.
    Type: Application
    Filed: February 19, 2002
    Publication date: June 27, 2002
    Applicant: FUJITSU LIMITED
    Inventors: Hirotaka Tamura, Miyoshi Saito, Kohtaroh Gotoh, Shigetoshi Wakayama, Junji Ogawa, Hisakatsu Araki, Tsz-shing Cheung
  • Patent number: 6377638
    Abstract: A signal transmission system has a response time of a signal transmission line which is set approximately equal to or longer than the length of a transmitted symbol. More specifically, terminal resistance is set larger than the characteristic impedance of the signal transmission line, driver output resistance is set to a large value, or a damping resistor is provided in series with the signal transmission line. With this configuration, signal power can be reduced drastically.
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: April 23, 2002
    Assignee: Fujitsu Limited
    Inventors: Hirotaka Tamura, Miyoshi Saito, Kohtaroh Gotoh, Shigetoshi Wakayama, Junji Ogawa, Hisakatsu Araki, Tsz-shing Cheung
  • Patent number: 6333883
    Abstract: A restoring circuit 24, provided for each of the memory blocks 191 and 192, having registers and a selector for selecting one of the present row address and the output of the registers, provides the output of the selector to a word decoder 26. The present row address is held in one of the registers. When amplification is started by a sense amplifier 15, transfer gates 10 and 11 connected between the bit lines BL1 and *BL1 and the sense amplifier 15 are turned off to decrease the load of the sense amplifier 15, the amplified signal is stored in a buffer memory cell circuit 18, and accessing is completed with omitting restoring to the memory cell 12. While the memory cell block 191 is not selected, the data held in the buffer memory cell circuit 18 is stored into the memory cell row addressed by the content of the selected register. The sense amplifier 15 has PMOS and NMOS sense amplifiers.
    Type: Grant
    Filed: January 25, 2001
    Date of Patent: December 25, 2001
    Assignee: Fujitsu Limited
    Inventors: Shigetoshi Wakayama, Kohtaroh Gotoh, Miyoshi Saito, Junji Ogawa