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).
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Patent number: 9236097Abstract: 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: GrantFiled: September 14, 2012Date of Patent: January 12, 2016Assignee: SOCIONEXT INC.Inventor: Hiroyuki Sugamoto
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Publication number: 20130070538Abstract: 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: ApplicationFiled: September 14, 2012Publication date: March 21, 2013Applicant: FUJITSU SEMICONDUCTOR LIMITEDInventor: Hiroyuki SUGAMOTO
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Publication number: 20100052727Abstract: 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: ApplicationFiled: November 9, 2009Publication date: March 4, 2010Applicant: FUJITSU LIMITEDInventors: Hiroyuki SUGAMOTO, Hidetoshi Tanaka, Yasushige Ogawa
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Patent number: 7663392Abstract: 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: GrantFiled: April 30, 2008Date of Patent: February 16, 2010Assignee: Fujitsu Microelectronics LimitedInventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Ogawa
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Patent number: 7593275Abstract: 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: GrantFiled: March 12, 2008Date of Patent: September 22, 2009Assignee: Fujitsu Microelectronics Ltd.Inventor: Hiroyuki Sugamoto
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Publication number: 20080225612Abstract: 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: ApplicationFiled: March 12, 2008Publication date: September 18, 2008Applicant: FUJITSU LIMITEDInventor: Hiroyuki SUGAMOTO
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Publication number: 20080204067Abstract: 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: ApplicationFiled: April 30, 2008Publication date: August 28, 2008Inventors: Hiroyuki SUGAMOTO, Hidetoshi Tanaka, Yasushige Ogawa
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Patent number: 7378863Abstract: 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: GrantFiled: December 20, 2004Date of Patent: May 27, 2008Assignee: Fujitsu LimitedInventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Ogawa
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Publication number: 20050111293Abstract: 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: ApplicationFiled: December 20, 2004Publication date: May 26, 2005Inventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Ogawa
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Patent number: 6891393Abstract: 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: GrantFiled: February 27, 2003Date of Patent: May 10, 2005Assignee: Fujitsu LimitedInventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Ogawa
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Patent number: 6741518Abstract: 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: GrantFiled: December 7, 2001Date of Patent: May 25, 2004Assignee: Fujitsu LimitedInventors: Kazumi Kojima, Yasushige Ogawa, Hiroyuki Sugamoto
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Publication number: 20030140290Abstract: 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: ApplicationFiled: February 27, 2003Publication date: July 24, 2003Applicant: FUJITSU LIMITEDInventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Ogawa
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Patent number: 6559669Abstract: 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: GrantFiled: March 30, 2001Date of Patent: May 6, 2003Assignee: Fujitsu LimitedInventors: Hiroyuki Sugamoto, Hidetoshi Tanaka, Yasushige Tanaka
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Patent number: 6545940Abstract: 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: GrantFiled: March 19, 2001Date of Patent: April 8, 2003Assignee: Fujitsu LimitedInventors: Hiroyuki Sugamoto, Satoshi Takashima, Yoshiyuki Ishida, Yasushige Ogawa
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Patent number: 6542421Abstract: 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: GrantFiled: October 2, 2001Date of Patent: April 1, 2003Assignee: Fujitsu LimitedInventors: Hiroyuki Sugamoto, Yasushige Ogawa
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Patent number: 6525975Abstract: 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: GrantFiled: September 7, 2001Date of Patent: February 25, 2003Assignee: Fujitsu LimitedInventors: Kazumi Kojima, Yasushige Ogawa, Hiroyuki Sugamoto
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Publication number: 20020191476Abstract: 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: ApplicationFiled: December 7, 2001Publication date: December 19, 2002Applicant: Fujitsu LimitedInventors: Kazumi Kojima, Yasushige Ogawa, Hiroyuki Sugamoto
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Patent number: 6469551Abstract: 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: GrantFiled: November 22, 1999Date of Patent: October 22, 2002Assignee: Fujitsu LimitedInventors: Isamu Kobayashi, Hiroyuki Sugamoto
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Publication number: 20020145927Abstract: 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: ApplicationFiled: September 7, 2001Publication date: October 10, 2002Applicant: FUJITSU LIMITEDInventors: Kazumi Kojima, Yasushige Ogawa, Hiroyuki Sugamoto
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Patent number: 6462997Abstract: 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: GrantFiled: January 10, 2001Date of Patent: October 8, 2002Assignee: Fujitsu LimitedInventors: Hiroyuki Sugamoto, Takaaki Furuyama