Patents by Inventor Takeshi Hamamoto

Takeshi Hamamoto 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).

  • Publication number: 20020196680
    Abstract: A setting circuit provided at a central part of a chip to set a replacement address includes seven redundancy determining units, each of which includes a program set. Each of four banks are divided into half to provide the total of eight regions. Eight control buses are provided transmitting data corresponding to the eight regions respectively. A bus determining unit selects a corresponding control bus in accordance with the contents of the program set and outputs replacement information. Therefore, each of the seven program sets can be used for replacement in any of the eight regions.
    Type: Application
    Filed: April 11, 2002
    Publication date: December 26, 2002
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tsukasa Ooishi, Takeshi Hamamoto
  • Patent number: 6489819
    Abstract: Pulses are generated using an edge of a clock signal applied from a low speed tester as a trigger, and internal clock signals are generated utilizing the pulses. Internal circuitry is operated in synchronization with the internal clock signals. Thus a synchronous semiconductor device operating at high speed can be tested using a low speed tester.
    Type: Grant
    Filed: October 27, 1998
    Date of Patent: December 3, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Kono, Takeshi Hamamoto, Yasuhiro Konishi
  • Publication number: 20020141280
    Abstract: A clock signal, which is generated by utilizing a delay circuit having a delay time depending on the operation frequency of an internal clock signal, is applied to a first circuit for activation thereof, and a clock signal, which has a fixed delay not dependent on the clock frequency and is adjusted in phase with respect to an external clock signal, is applied to a second circuit receiving the output signal of the first circuit for operation thereof. Thus, the operation timing of the second circuit can be set to be as late as possible. Consequently, it is possible to mitigate the operation conditions of the first circuit, to achieve a high speed data transfer. Even in the high speed operation, internal data can be reliably taken in, and transferred accurately.
    Type: Application
    Filed: January 3, 2002
    Publication date: October 3, 2002
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Hamamoto, Takeo Miki
  • Patent number: 6449198
    Abstract: In the SDRAM, a selector selects one of four global IO line pairs according to a column block select signal and a word configuration selecting signal, and connects the selected global IO line pair to an input/output node pair of a preamplifier in a pulsed manner for a prescribed period of time. Since the equalization of the global IO line pair can be started immediately after the global IO line pair is connected in a pulsed manner to the input/output node pair of the preamplifier, longer equalization period for the global IO line can be set aside so that the read operation can be stabilized.
    Type: Grant
    Filed: November 22, 2000
    Date of Patent: September 10, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kei Hamade, Takeshi Hamamoto, Masaru Haraguchi, Yasuhiro Konishi
  • Patent number: 6438067
    Abstract: A DLL circuit includes a delay circuit for producing an output clock signal by delaying an input clock signal, and a phase comparator circuit for making a comparison between phases of the output and input clock signals. The delay circuit includes a plurality of delay units each having a unit delay amount changing in accordance with a drive potential level. The DLL circuit further includes a delay control circuit for controlling activation of the delay units in accordance with the result of phase comparison of the phase comparator circuit, and a drive potential control circuit for controlling the drive potential in accordance with the result of phase comparison of the phase comparator circuit.
    Type: Grant
    Filed: February 2, 2001
    Date of Patent: August 20, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigehiro Kuge, Takeshi Hamamoto
  • Publication number: 20020110939
    Abstract: A semiconductor chip is provided with a phase comparison circuit (1), in addition to an integrated circuit implementing a normal operation. The phase comparison circuit (1) compares phases between an internal signal (A) of the integrated circuit and an external signal and outputs a monitor signal (MONSIG) expressing the result of this comparison outward from the semiconductor chip. Thus, the phase of the internal signal (A) of the integrated circuit can be directly detected.
    Type: Application
    Filed: July 18, 2001
    Publication date: August 15, 2002
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Takeo Miki, Takeshi Hamamoto
  • Patent number: 6417715
    Abstract: A clock generation circuit includes a clock input circuit receiving complementary external clocks to generate an internal clock, a variable delay circuit delaying the internal clock to generate an internal operation clock, a replica circuit further delaying the internal operation clock by a predetermined time to generate a return clock, a phase comparator directly comparing the phase where potential levels of external clocks cross with the phase of the return clock, and a delay control circuit adjusting the delay amount of the variable delay circuit according to a phase comparison result of the phase comparator.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: July 9, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Hamamoto, Kiyohiro Furutani
  • Patent number: 6414891
    Abstract: A semiconductor memory device includes a pair of complementary data buses, capacitive element corresponding to an even-numbered address, an equalize circuit and amplifier, capacitive element corresponding to an odd-numbered address, and an equalize circuit and amplifier. The pair of complementary data buses continuously transfer even-numbered address data and odd-numbered address data read out from the memory cell array in an alternating manner. The equalize circuit corresponding to the odd-numbered address is operated when the amplifier corresponding to the even-numbered address operates whereas the equalize circuit corresponding to the even-numbered address is operated when the amplifier corresponding to the odd-numbered address operates.
    Type: Grant
    Filed: January 30, 2001
    Date of Patent: July 2, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigehiro Kuge, Takeshi Hamamoto
  • Publication number: 20020047089
    Abstract: An optical proximity effect correcting method in a semiconductor manufacturing process includes adding, detecting, judging, and deleting. The adding includes adding a first correcting region around a portion of a first design pattern. The portion faces a second design pattern. A first corrected design pattern includes the first correcting region and the first design pattern. The detecting includes detecting a space between the first corrected design pattern and the second design pattern. The judging includes judging whether the space is smaller than or equal to a predetermined value. The deleting includes deleting at least a portion of the first correcting region such that the space is larger than the predetermined value, when the space is smaller than or equal to the predetermined value.
    Type: Application
    Filed: December 4, 2001
    Publication date: April 25, 2002
    Inventors: Keiichiro Tounai, Takeshi Hamamoto
  • Patent number: 6377512
    Abstract: Data buses are arranged in a one-to-one correspondence to pads. These data buses are arranged in common to a plurality of memory arrays. A read data driver is rendered active selectively according to a word configuration to switch equivalently the connection between a memory array and a data bus.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: April 23, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Hamamoto, Takuya Ariki, Mikio Asakura, Takayuki Nishiyama
  • Publication number: 20020043615
    Abstract: An optical proximity effect correcting method in a semiconductor manufacturing process includes adding, detecting, judging, and deleting. The adding includes adding a first correcting region around a portion of a first design pattern. The portion faces a second design pattern. A first corrected design pattern includes the first correcting region and the first design pattern. The detecting includes detecting a space between the first corrected design pattern and the second design pattern. The judging includes judging whether the space is smaller than or equal to a predetermined value. The deleting includes deleting at least a portion of the first correcting region such that the space is larger than the predetermined value, when the space is smaller than or equal to the predetermined value.
    Type: Application
    Filed: December 4, 2001
    Publication date: April 18, 2002
    Inventors: Keiichiro Tounai, Takeshi Hamamoto
  • Publication number: 20020024082
    Abstract: A buried strap is formed after forming an SiC layer on the side surface of a trench in order to suppress the epitaxial growth of Si from the side surface (single crystal Si) of the trench to the buried strap (polycrystalline Si) without causing an increase in the contact resistance in the post process accompanied by high temperature after formation of the buried strap.
    Type: Application
    Filed: October 26, 2001
    Publication date: February 28, 2002
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshitaka Tsunashima, Katsuya Okumura, Masayuki Tanaka, Shigehiko Saida, Hirofumi Inoue, Takeshi Hamamoto
  • Patent number: 6343035
    Abstract: When a first data bus line and a second data bus line as a pair are used as a complementary bus, a complementary data signal ZDATA1 is provided to the second data bus line, and an output buffer circuit that becomes unnecessary is rendered inactive. On the other hand, when the first and second data bus lines are used as two single data buses, a differential amplifier transmits two data signals without amplification to the first and second data bus lines. A data signal DATA2 is provided to the second data bus line. The output buffer circuit is activated, and a data signal ZDATA2 is output from an output node.
    Type: Grant
    Filed: November 9, 2000
    Date of Patent: January 29, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Kubo, Jun Setogawa, Takeshi Hamamoto
  • Publication number: 20020003730
    Abstract: The semiconductor memory device has a word configuration determination signal generating circuit including a plurality of generating circuits, each of which is formed of two clocked inverters and two inverters. In a normal operation mode, a test mode signal TX4 is inactivated and a word configuration determination signal [×16E] of an H level is output. In a test mode, the test mode signal TX4 is activated and a word configuration determination signal [×4E] of an H level is output. Thus, in the test mode, the word configuration is switched to the one that is smaller than in the normal operation mode. This allows simultaneous testing of a larger number of semiconductor memory devices.
    Type: Application
    Filed: December 4, 2000
    Publication date: January 10, 2002
    Inventors: Shigekazu Aoki, Seiji Sawada, Mikio Asakura, Takeshi Hamamoto, Masakazu Hirose
  • Patent number: 6337824
    Abstract: A decoupling capacitor is coupled to a sense power supply line with respect to a sense amplifier circuit group, and the sense power supply line is selectively coupled with a power supply node in response to an operation mode of a sense amplifier. In a sensing operation, the potential of a bit line is determined by redistribution of charges between the decoupling capacitor and a load capacitor of the bit line. Refresh characteristics is improved without increasing a sense current and showing down the sensing operation.
    Type: Grant
    Filed: December 7, 1999
    Date of Patent: January 8, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Kono, Takeshi Hamamoto
  • Patent number: 6335887
    Abstract: The semiconductor memory device has a word configuration determination signal generating circuit including a plurality of generating circuits, each of which is formed of two clocked inverters and two inverters. In a normal operation mode, a test mode signal TX4 is inactivated and a word configuration determination signal [x16E] of an H level is output. In a test mode, the test mode signal TX4 is activated and a word configuration determination signal [x4E] of an H level is output. Thus, in the test mode, the word configuration is switched to the one that is smaller than in the normal operation mode. This allows simultaneous testing of a larger number of semiconductor memory devices.
    Type: Grant
    Filed: December 4, 2000
    Date of Patent: January 1, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigekazu Aoki, Seiji Sawada, Mikio Asakura, Takeshi Hamamoto, Masakazu Hirose
  • Patent number: 6333895
    Abstract: In an output data control circuit for transferring complementary data signals read from a memory array to an external data output node in accordance with an output clock signal, a clocked gate circuit transferring complementary data signals in synchronization with an output clock signal and an output data latch circuit latching an output signal of the clocked gate circuit are operated using a voltage level not exceeding an internal power supply voltage, and the complementary data signals read from a memory cell is subjected to an amplitude expanding processing in a stage preceding the clocked gate circuit, and then is applied to the clocked gate circuit. A clock synchronous semiconductor memory device allowing reduction of a clock access time is provided.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: December 25, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Hamamoto, Satoshi Kawasaki
  • Patent number: 6333670
    Abstract: Change in internal voltage on an internal voltage line is detected as discharging current of a capacitance element via an MOS transistor to change a charged voltage of the capacitance element. According to the charged voltage of the capacitance element, a current drive transistor is driven to supply a current to the internal voltage line. The internal voltage is stably generated with low current consumption and small occupation area.
    Type: Grant
    Filed: December 8, 1999
    Date of Patent: December 25, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Kono, Takeshi Hamamoto
  • Patent number: 6333892
    Abstract: A command decoder receives an externally supplied command independently of an internal clock signal, decodes the command, generates a column access mode instruction signal, and activates a column address activation signal when the internal clock signal rises. An internal column address signal generating circuit generates an internal column address signal from an externally supplied address signal according to the column address activation signal. Accordingly, the internal column address is generated at an advanced timing to enable a following column selecting operation to be started at a faster timing. A synchronous semiconductor memory device capable of performing the column selecting operation at a high speed is thus provided.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: December 25, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Hamamoto, Zenya Kawaguchi, Motoko Hara
  • Publication number: 20010054164
    Abstract: In the semiconductor memory device, a control circuit generates various commands for a memory cell array according to an internal command control signal and an internal address signal output from an input switching circuit for switching an input source of the command control signals and the address signal between an external terminal and a BIST circuit. In the BIST mode, the input switching circuit cuts the signal input from the external terminal and generates the internal command control signal and the internal address signal according to an output signal from the BIST circuit. Transition to the BIST mode and return to the normal operation mode are indicated by a combination of signals supplied to the external terminal. Therefore, an interface between a built in BIST circuit and other internal circuits can be secured without an addition of a special interface specification.
    Type: Application
    Filed: January 11, 2001
    Publication date: December 20, 2001
    Inventors: Tetsushi Tanizaki, Takeshi Hamamoto