Patents by Inventor Hiroyuki Sugamoto

Hiroyuki Sugamoto 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: 9236097
    Abstract: A semiconductor memory device includes two memory cell arrays, a sense amplifier shared by the two memory cell arrays; and a control circuit configured to control data readout from the two memory cell arrays. Each memory cell array includes word lines, two or more bit lines, a dummy word line, memory cells provided at intersections of the bit lines and the word lines, and dummy cells provided at intersections of selected bit lines and the dummy word line. When the control circuit reads data from one memory cell array, the control circuit activates the dummy word line included in the other memory cell array and generates, with the dummy cell included in the other memory cell array, a reference level of the sense amplifier.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: January 12, 2016
    Assignee: SOCIONEXT INC.
    Inventor: Hiroyuki Sugamoto
  • Publication number: 20130070538
    Abstract: A semiconductor memory device includes two memory cell arrays, a sense amplifier shared by the two memory cell arrays; and a control circuit configured to control data readout from the two memory cell arrays. Each memory cell array includes word lines, two or more bit lines, a dummy word line, memory cells provided at intersections of the bit lines and the word lines, and dummy cells provided at intersections of selected bit lines and the dummy word line. When the control circuit reads data from one memory cell array, the control circuit activates the dummy word line included in the other memory cell array and generates, with the dummy cell included in the other memory cell array, a reference level of the sense amplifier.
    Type: Application
    Filed: September 14, 2012
    Publication date: March 21, 2013
    Applicant: FUJITSU SEMICONDUCTOR LIMITED
    Inventor: Hiroyuki SUGAMOTO
  • Publication number: 20100052727
    Abstract: The present invention provides a synchronous semiconductor device suitable for improving the efficiency of application of electrical stresses to the device, an inspection system and an inspection method thereof in order to efficiently carry out a burn-in stress test. A command latch circuit having an access command input will output a low-level pulse in synchronism with an external clock. The pulse will pass through a NAND gate of test mode sequence circuit and a common NAND gate to output a low-level internal precharge signal, which will resent a word line activating signal from the control circuit. Simultaneously, an internal precharge signal passing through the NAND gate will be delayed by an internal timer a predetermined period of time to output through the NAND gate a low-level internal active signal, which will set a word line activating signal from the control circuit.
    Type: Application
    Filed: November 9, 2009
    Publication date: March 4, 2010
    Applicant: FUJITSU LIMITED
    Inventors: Hiroyuki SUGAMOTO, Hidetoshi Tanaka, Yasushige Ogawa
  • Patent number: 7663392
    Abstract: The present invention provides a synchronous semiconductor device suitable for improving the efficiency of application of electrical stresses to the device, an inspection system and an inspection method thereof in order to efficiently carrying out a burn-in stress test. A command latch circuit having an access command input will output a low-level pulse in synchronism with an external clock. The pulse will pass through a NAND gate of test mode sequence circuit and a common NAND gate to output a low-level internal precharge signal, which will reset a word line activating signal from the control circuit. Simultaneously, an internal precharge signal passing through the NAND gate will be delayed by an internal timer a predetermined period of time to output through the NAND gate a low-level internal active signal, which will set a word line activating signal from the control circuit.
    Type: Grant
    Filed: April 30, 2008
    Date of Patent: February 16, 2010
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Ogawa
  • Patent number: 7593275
    Abstract: According to an aspect of one embodiment, it is provided that semiconductor memory device determining a data read time required to read data from a memory cell by an operation to read a replica cell to which a replica bit line having a load equivalent to a bit line to be connected to the memory cell and a replica word line are connected, the semiconductor memory device comprising: a write control signal generating unit that includes logic gates coupled in multi stages for receiving an input of a replica word line activating signal generated in response to a driving signal for driving the replica word line, the write control signal generating unit generating a write control signal to determine a data write time required to write data in the memory cell based on the replica word line activating signal.
    Type: Grant
    Filed: March 12, 2008
    Date of Patent: September 22, 2009
    Assignee: Fujitsu Microelectronics Ltd.
    Inventor: Hiroyuki Sugamoto
  • Publication number: 20080225612
    Abstract: According to an aspect of one embodiment, it is provided that semiconductor memory device determining a data read time required to read data from a memory cell by an operation to read a replica cell to which a replica bit line having a load equivalent to a bit line to be connected to the memory cell and a replica word line are connected, the semiconductor memory device comprising: a write control signal generating unit that includes logic gates coupled in multi stages for receiving an input of a replica word line activating signal generated in response to a driving signal for driving the replica word line, the write control signal generating unit generating a write control signal to determine a data write time required to write data in the memory cell based on the replica word line activating signal.
    Type: Application
    Filed: March 12, 2008
    Publication date: September 18, 2008
    Applicant: FUJITSU LIMITED
    Inventor: Hiroyuki SUGAMOTO
  • Publication number: 20080204067
    Abstract: The present invention provides a synchronous semiconductor device suitable for improving the efficiency of application of electrical stresses to the device, an inspection system and an inspection method thereof in order to efficiently carrying out a burn-in stress test. A command latch circuit having an access command input will output a low-level pulse in synchronism with an external clock. The pulse will pass through a NAND gate of test mode sequence circuit and a common NAND gate to output a low-level internal precharge signal, which will reset a word line activating signal from the control circuit. Simultaneously, an internal precharge signal passing through the NAND gate will be delayed by an internal timer a predetermined period of time to output through the NAND gate a low-level internal active signal, which will set a word line activating signal from the control circuit.
    Type: Application
    Filed: April 30, 2008
    Publication date: August 28, 2008
    Inventors: Hiroyuki SUGAMOTO, Hidetoshi Tanaka, Yasushige Ogawa
  • Patent number: 7378863
    Abstract: The present invention provides a synchronous semiconductor device suitable for improving the efficiency of application of electrical stresses to the device, an inspection system and an inspection method thereof in order to efficiently carrying out a burn-in stress test. A command latch circuit having an access command input will output a low-level pulse in synchronism with an external clock. The pulse will pass through a NAND gate of test mode sequence circuit and a common NAND gate to output a low-level internal precharge signal, which will reset a word line activating signal from the control circuit. Simultaneously, an internal precharge signal passing through the NAND gate will be delayed by an internal timer a predetermined period of time to output through the NAND gate a low-level internal active signal, which will set a word line activating signal from the control circuit.
    Type: Grant
    Filed: December 20, 2004
    Date of Patent: May 27, 2008
    Assignee: Fujitsu Limited
    Inventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Ogawa
  • Publication number: 20050111293
    Abstract: The present invention provides a synchronous semiconductor device suitable for improving the efficiency of application of electrical stresses to the device, an inspection system and an inspection method thereof in order to efficiently carrying out a burn-in stress test. A command latch circuit having an access command input will output a low-level pulse in synchronism with an external clock. The pulse will pass through a NAND gate of test mode sequence circuit and a common NAND gate to output a low-level internal precharge signal, which will reset a word line activating signal from the control circuit. Simultaneously, an internal precharge signal passing through the NAND gate will be delayed by an internal timer a predetermined period of time to output through the NAND gate a low-level internal active signal, which will set a word line activating signal from the control circuit.
    Type: Application
    Filed: December 20, 2004
    Publication date: May 26, 2005
    Inventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Ogawa
  • Patent number: 6891393
    Abstract: The present invention provides a synchronous semiconductor device suitable for improving the efficiency of application of electrical stresses to the device, an inspection system and an inspection method thereof in order to efficiently carrying out a burn-in stress test. A command latch circuit having an access command input will output a low-level pulse in synchronism with an external clock. The pulse will pass through a NAND gate of test mode sequence circuit and a common NAND gate to output a low-level internal precharge signal, which will reset a word line activating signal from the control circuit. Simultaneously, an internal precharge signal passing through the NAND gate will be delayed by an internal timer a predetermined period of time to output through the NAND gate a low-level internal active signal, which will set a word line activating signal from the control circuit.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: May 10, 2005
    Assignee: Fujitsu Limited
    Inventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Ogawa
  • Patent number: 6741518
    Abstract: Provided is a semiconductor integrated circuit device capable of, when data is written into a memory cell, fixing adjacent complimentary bit lines to a predetermined voltage, thereby reducing an effect of a write noise for a readout operation of the adjacent cells, making it possible to ensure stable operation. An address signal is inputted to a bit line short signal circuit and a column switch signal circuit, and the corresponding bit line short signal BRS0 or BRS1 and column switch signal CL01 or CL11 are selected. Complimentary bit lines /BL1, /BL2 or bit lines BL1 and BL2 in which a memory cell is not connected according to the bit line short signals BRS0 and BRS1 are selected altogether, these bit lines are fixed to a precharge voltage VPR, and a write noise is shielded. The column switch signal CL01 or CL11 makes conductive the corresponding column switches, and the selected bit line BL1, BL2, /BL1, or /BL2 is connected to a data bus DB or /DB.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: May 25, 2004
    Assignee: Fujitsu Limited
    Inventors: Kazumi Kojima, Yasushige Ogawa, Hiroyuki Sugamoto
  • Publication number: 20030140290
    Abstract: The present invention provides a synchronous semiconductor device suitable for improving the efficiency of application of electrical stresses to the device, an inspection system and an inspection method thereof in order to efficiently carrying out a burn-in stress test. A command latch circuit having an access command input will output a low-level pulse in synchronism with an external clock. The pulse will pass through a NAND gate of test mode sequence circuit and a common NAND gate to output a low-level internal precharge signal, which will reset a word line activating signal from the control circuit. Simultaneously, an internal precharge signal passing through the NAND gate will be delayed by an internal timer a predetermined period of time to output through the NAND gate a low-level internal active signal, which will set a word line activating signal from the control circuit.
    Type: Application
    Filed: February 27, 2003
    Publication date: July 24, 2003
    Applicant: FUJITSU LIMITED
    Inventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Ogawa
  • Patent number: 6559669
    Abstract: The present invention provides a synchronous semiconductor device suitable for improving the efficiency of application of electrical stresses to the device, an inspection system and an inspection method thereof in order to efficiently carrying out a burn-in stress test. A command latch circuit having an access command input will output a low-level pulse in synchronism with an external clock. The pulse will pass through a NAND gate of test mode sequence circuit and a common NAND gate to output a low-level internal precharge signal, which will reset a word line activating signal from the control circuit. Simultaneously, an internal precharge signal passing through the NAND gate will be delayed by an internal timer a predetermined period of time to output through the NAND gate a low-level internal active signal, which will set a word line activating signal from the control circuit.
    Type: Grant
    Filed: March 30, 2001
    Date of Patent: May 6, 2003
    Assignee: Fujitsu Limited
    Inventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Tanaka
  • Patent number: 6545940
    Abstract: A semiconductor integrated circuit that acquires an external signal precisely in a high speed operation. The semiconductor integrated circuit includes an internal circuit for acquiring an external signal in response to an address acquisition signal. A first holding circuit is connected to the internal circuit to hold the external signal for a predetermined period in response to a holding signal and provide the held external signal to the internal circuit. A control circuit is connected to the first holding circuit to generate the holding signal using the address acquisition signal.
    Type: Grant
    Filed: March 19, 2001
    Date of Patent: April 8, 2003
    Assignee: Fujitsu Limited
    Inventors: Hiroyuki Sugamoto, Satoshi Takashima, Yoshiyuki Ishida, Yasushige Ogawa
  • Patent number: 6542421
    Abstract: This invention provides a semiconductor memory device with a shift redundancy circuit which has a shortened redundancy operation. The semiconductor memory device of the present invention includes a plurality of shift switches and a changeover signal generating circuit connected to the shift switches. The changeover signal generating circuit may have a plurality of signal generating blocks including a first signal generating block for generating a first group of changeover signals and a second signal generating block for generating a second group of changeover signals.
    Type: Grant
    Filed: October 2, 2001
    Date of Patent: April 1, 2003
    Assignee: Fujitsu Limited
    Inventors: Hiroyuki Sugamoto, Yasushige Ogawa
  • Patent number: 6525975
    Abstract: There is intended to provide a semiconductor integrated circuit device capable of lowering the power consumption during data-write operation, enhancing operation speed, and reducing noises for stable operation. In the semiconductor integrated circuit, an active signal ACT to be inputted to a sense amplifier signal circuit SC1 is latched by a command latch circuit and outputted to a terminal N11. The terminal N11 outputs a control signal EDC1 via a timing adjusting circuit. The control signal EDC1 works to output a sense amplifier activating signal LE via a timing adjusting circuit and output buffer circuit and at the same time, the control signal EDC1 is outputted to a column switch signal circuit CS1. From the Column switch signal circuit CS1, a pulse signal is outputted via input of a control signal ACL, a pulse output circuit, and a terminal N13. In a logical circuit, AND processing is conducted between the pulse signal and an inversion signal of the control signal EDC1.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: February 25, 2003
    Assignee: Fujitsu Limited
    Inventors: Kazumi Kojima, Yasushige Ogawa, Hiroyuki Sugamoto
  • Publication number: 20020191476
    Abstract: Provided is a semiconductor integrated circuit device capable of, when data is written into a memory cell, fixing adjacent complimentary bit lines to a predetermined voltage, thereby reducing an effect of a write noise for a readout operation of the adjacent cells, making it possible to ensure stable operation. An address signal is inputted to a bit line short signal circuit and a column switch signal circuit, and the corresponding bit line short signal BRS0 or BRS1 and column switch signal CL01 or CL11 are selected. Complimentary bit lines /BL1, /BL2 or bit lines BL1 and BL2 in which a memory cell is not connected according to the bit line short signals BRS0 and BRS1 are selected altogether, these bit lines are fixed to a precharge voltage VPR, and a write noise is shielded. The column switch signal CL01 or CL11 makes conductive the corresponding column switches, and the selected bit line BL1, BL2, /BL1, or /BL2 is connected to a data bus DB or /DB.
    Type: Application
    Filed: December 7, 2001
    Publication date: December 19, 2002
    Applicant: Fujitsu Limited
    Inventors: Kazumi Kojima, Yasushige Ogawa, Hiroyuki Sugamoto
  • Patent number: 6469551
    Abstract: A starting circuit for an integrated circuit (IC) device insures that the IC device is properly initialized before an initialization signal is dropped. The starting circuit, which receives power from high and low potential power supplies, includes a first transistor having a threshold voltage within a known range. The first transistor receives a control voltage generated from the high and low potential power supplies and produces a start (initialization) signal, from the time that the high potential power supply voltage begins to rise to when the control voltage rises to the first transistor threshold voltage. A correction circuit connected to the first transistor adjusts the control voltage in accordance with the threshold voltage of the first transistor.
    Type: Grant
    Filed: November 22, 1999
    Date of Patent: October 22, 2002
    Assignee: Fujitsu Limited
    Inventors: Isamu Kobayashi, Hiroyuki Sugamoto
  • Publication number: 20020145927
    Abstract: There is intended to provide a semiconductor integrated circuit device capable of lowering the power consumption during data-write operation, enhancing operation speed, and reducing noises for stable operation. In the semiconductor integrated circuit, an active signal ACT to be inputted to a sense amplifier signal circuit SC1 is latched by a command latch circuit and outputted to a terminal N11. The terminal N11 outputs a control signal EDC1 via a timing adjusting circuit. The control signal EDC1 works to output a sense amplifier activating signal LE via a timing adjusting circuit and output buffer circuit and at the same time, the control signal EDC1 is outputted to a column switch signal circuit CS1. From the Column switch signal circuit CS1, a pulse signal is outputted via input of a control signal ACL, a pulse output circuit, and a terminal N13. In a logical circuit, AND processing is conducted between the pulse signal and an inversion signal of the control signal EDC1.
    Type: Application
    Filed: September 7, 2001
    Publication date: October 10, 2002
    Applicant: FUJITSU LIMITED
    Inventors: Kazumi Kojima, Yasushige Ogawa, Hiroyuki Sugamoto
  • Patent number: 6462997
    Abstract: A semiconductor memory, such as an SDRAM, includes a data bus pair, a first reset circuit, a second reset circuit and a control circuit. The first reset circuit is connected between the buses of the data bus pair and resets the buses at a first potential. The second reset circuit is also connected between the data buses and resets the buses at a second potential. The control circuit is connected to the first and second reset circuits and activates the first reset circuit and deactivates the second reset circuit prior to a write operation. The control circuit further deactivates the first reset circuit and activates the second reset circuit prior to a read operation.
    Type: Grant
    Filed: January 10, 2001
    Date of Patent: October 8, 2002
    Assignee: Fujitsu Limited
    Inventors: Hiroyuki Sugamoto, Takaaki Furuyama