Patents by Inventor Yukinori Kodama

Yukinori Kodama 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: 7320079
    Abstract: A semiconductor integrated circuit is disclosed that operates in synch with a clock signal supplied from an external source, and by a voltage supplied by a power supply. The circuit includes a detection means for detecting that at least one of a frequency of the clock signal and the supply voltage is reduced, and an internal voltage reduction means for lowering an internal voltage of the semiconductor integrated circuit when the detection means detects that at least one of the frequency and the supply voltage is lowered.
    Type: Grant
    Filed: August 7, 2006
    Date of Patent: January 15, 2008
    Assignee: Fujitsu Limited
    Inventors: Takaaki Suzuki, Sumie Kodama, legal representative, Yukinori Kodama, deceased
  • Patent number: 7302598
    Abstract: A semiconductor integrated circuit is disclosed that operates in synch with a clock signal supplied from an external source, and by a voltage supplied by a power supply. The circuit includes a detection means for detecting that at least one of a frequency of the clock signal and the supply voltage is reduced, and an internal voltage reduction means for lowering an internal voltage of the semiconductor integrated circuit when the detection means detects that at least one of the frequency and the supply voltage is lowered.
    Type: Grant
    Filed: April 23, 2004
    Date of Patent: November 27, 2007
    Assignee: Fujitsu Limited
    Inventors: Takaaki Suzuki, Sumie Kodama, legal representative, Yukinori Kodama, deceased
  • Publication number: 20060271807
    Abstract: A semiconductor integrated circuit is disclosed that operates in synch with a clock signal supplied from an external source, and by a voltage supplied by a power supply. The circuit includes a detection means for detecting that at least one of a frequency of the clock signal and the supply voltage is reduced, and an internal voltage reduction means for lowering an internal voltage of the semiconductor integrated circuit when the detection means detects that at least one of the frequency and the supply voltage is lowered.
    Type: Application
    Filed: August 7, 2006
    Publication date: November 30, 2006
    Inventors: Takaaki Suzuki, Yukinori Kodama, Sumie Kodama
  • Publication number: 20040199803
    Abstract: A semiconductor integrated circuit is disclosed that operates in synch with a clock signal supplied from an external source, and by a voltage supplied by a power supply. The circuit includes a detection means for detecting that at least one of a frequency of the clock signal and the supply voltage is reduced, and an internal voltage reduction means for lowering an internal voltage of the semiconductor integrated circuit when the detection means detects that at least one of the frequency and the supply voltage is lowered.
    Type: Application
    Filed: April 23, 2004
    Publication date: October 7, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Takaaki Suzuki, Yukinori Kodama, Sumie Kodama
  • Patent number: 6166992
    Abstract: A semiconductor device includes a one-shot pulse generating circuit that generates a one-shot pulse having a predetermined pulse width at a rise or fall timing of a first clock signal, a cycle time measuring circuit that measures a cycle-time of the first clock signal from the one-shot pulse output from the one-shot pulse generating circuit, an internal clock generating circuit that generates a second clock signal based on the cycle time measured by the cycle time measuring circuit and the one-shot pulse output from the one-shot pulse generating circuit. The second clock signal has a cycle time identical to the first clock signal and has a rise or fall timing which is advanced by a specific time than that of the first clock signal, and the specific time is obtained by subtracting the cycle time of the first clock signal from a predetermined time, and a data output circuit that outputs data after a predetermined delay time from the rise or fall timing of the second clock signal.
    Type: Grant
    Filed: March 2, 2000
    Date of Patent: December 26, 2000
    Assignee: Fujitsu Limited
    Inventors: Yoshihiro Takemae, Masao Taguchi, Yukinori Kodama, Makoto Yanagisawa, Takaaki Suzuki, Junji Ogawa, Atsushi Hatakeyama, Hirohiko Mochizuki, Hideaki Kawai
  • Patent number: 6009039
    Abstract: A semiconductor device includes a one-shot pulse generating circuit that generates a one-shot pulse having a predetermined pulse width at a rise or fall timing of a first clock signal, a cycle time measuring circuit that measures a cycle time of the first clock signal from the one-shot pulse output from the one-shot pulse generating circuit, an internal clock generating circuit that generates a second clock signal based on the cycle time measured by the cycle time measuring circuit and the one-shot pulse output from the one-shot pulse generating circuit. The second clock signal has a cycle time identical to the first clock signal and has a rise or fall timing which is advanced by a specific time than that of the first clock signal, and the specific time is obtained by subtracting the cycle time of the first clock signal from a predetermined time, and a data output circuit that outputs data after a predetermined delay time from the rise or fall timing of the second clock signal.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: December 28, 1999
    Assignee: Fujitsu Limited
    Inventors: Yoshihiro Takemae, Masao Taguchi, Yukinori Kodama, Makoto Yanagisawa, Takaaki Suzuki, Junji Ogawa, Atsushi Hatakeyama, Hirohiko Mochizuki, Hideaki Kawai
  • Patent number: 5767712
    Abstract: A semiconductor device includes a one-shot pulse generating circuit that generates a one-shot pulse having a predetermined pulse width at a rise or fall timing of a first clock signal, a cycle time measuring circuit that measures a cycle time of the first clock signal from the one-shot pulse output from the one-shot pulse generating circuit, an internal clock generating circuit that generates a second clock signal based on the cycle time measured by the cycle time measuring circuit and the one-shot pulse output from the one-shot pulse generating circuit. The second clock signal has a cycle time identical to the first clock signal and has rise or fall timing which is advanced by a specific time than that of the first clock signal, and the specific time is obtained by subtracting the cycle time of the first clock signal from a predetermined time, and a data output circuit that outputs data after a predetermined delay time from the rise or fall timing of the second clock signal.
    Type: Grant
    Filed: July 14, 1997
    Date of Patent: June 16, 1998
    Assignee: Fujitsu Limited
    Inventors: Yoshihiro Takemae, Masao Taguchi, Yukinori Kodama, Makoto Yanagisawa, Takaaki Suzuki, Junji Ogawa, Atsushi Hatakeyama, Hirohiko Mochizuki, Hideaki Kawai
  • Patent number: 5631866
    Abstract: A synchronous DRAM is disclosed. The DRAM comprises an input buffer, a memory cell array, an output buffer, a signal transfer circuit, first and second latch circuits, and a controller. The input buffer receives an operation control signal supplied externally. The memory cell array has a plurality of memory cells for storing data. The output buffer outputs a data signal read from the memory cells. The signal transfer circuit reads a data signal from one of the memory cells in accordance with the operation control signal from the input buffer, and sends this read data signal to the output buffer. The first and second latch circuits, provided between the input buffer and the output buffer, latch the associated input signals in response to a clock signal.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: May 20, 1997
    Assignee: Fujitsu Limited
    Inventors: Tomoharu Oka, Yukinori Kodama, Katsumi Shigenobu
  • Patent number: 5592433
    Abstract: A semiconductor memory device includes a memory cell array in which a number of sense amplifiers are provided, a plurality of segmented drive lines each connected to a group of sense amplifiers for driving the same, each of the segmented drive lines being formed of first and second drive line segments forming a pair, and a number of trunks for supplying electric power to the segmented drive lines. Each of the trunks includes a first conductor strip extending from a first side of the memory cell array toward a second side for connection to a plurality of the first drive line segments upon crossing the same, and a second conductor strip extending from the second side of the memory cell array toward the first side for connection to a plurality of the second drive line segments upon crossing the same.
    Type: Grant
    Filed: May 7, 1996
    Date of Patent: January 7, 1997
    Assignee: Fujitsu Limited
    Inventors: Hiroyoshi Tomita, Makoto Yanagisawa, Yukinori Kodama
  • Patent number: 5537354
    Abstract: A method of making an SDRAM (synchronous dynamic random access memory) into either a low-speed type or a high-speed type includes the steps of determining an electrical connection of a predetermined electrode of the SDRAM, and providing the predetermined electrode with a voltage level defined by the electrical connection, the voltage level determining whether the SDRAM is made into the low-speed type or the high speed type, wherein the low-speed type can carry out consecutive writing operations at a low clock rate for two addresses having the same row address, and the high-speed type can carry out simultaneous writing operations at a high clock rate for two addresses having the same row address and consecutive column addresses.
    Type: Grant
    Filed: December 14, 1994
    Date of Patent: July 16, 1996
    Assignee: Fujitsu Limited
    Inventors: Hirohiko Mochizuki, Yoshihiro Takemae, Yukinori Kodama, Makoto Yanagisawa, Hiroyoshi Tomita
  • Patent number: 5535169
    Abstract: A semiconductor memory device includes a plurality of banks each having a memory cell array and sense amplifiers, a data input/output circuit and an address circuit. A first part of the device receives control signals from an outside of the semiconductor memory device and generates a refresh signal therefrom. A second part generates bank select signals in response to the refresh signal, the bank select signals being used to select the plurality of banks. A third part receives the bank select signals and generating latch enable signals therefrom, the latch enable signals driving the sense amplifiers provided in the plurality of banks. A refresh operation is carried out by activating the sense amplifiers by using the latch enable signals.
    Type: Grant
    Filed: October 13, 1994
    Date of Patent: July 9, 1996
    Assignee: Fujitsu Limited
    Inventors: Tetsuya Endo, Hirohiko Mochizuki, Yukinori Kodama, Yoshihiro Takemae
  • Patent number: 5528540
    Abstract: A comparator 5 outputs a match signal EQ and a redundancy selection signal with active when an address A4 to A0 is a redundant address in order to select a redundant word line RWL0 or RWL1 for replacing word line WL0 or WL1. A decoder 61 supplies a potential VCC+.alpha. to a drain of an FET 60 when both the match signal EQ and the redundancy selection signal S0 are active. A gate driver 62 supplies a high potential VCC to the gate of the FET 60 for turning ON the FET 60 when the redundancy selection signal S0 is active.
    Type: Grant
    Filed: October 7, 1994
    Date of Patent: June 18, 1996
    Assignee: Fujitsu Limited
    Inventors: Kenji Shibata, Yukinori Kodama
  • Patent number: 5483497
    Abstract: A semiconductor memory having a plurality of banks, a first specify unit, and a second specify unit. The first specify unit is used to specify one of the banks by decoding a bank address signal contained in a row address signal. The second specify unit is used to specify one of the banks by decoding the bank address signal contained in the row address signal, according to bank status signals that indicate whether or not each of the banks is activated. Therefore, the semiconductor memory is used for different bank configurations. Namely, with this arrangement, the semiconductor memory is capable of serving as a memory having a smaller number of banks, to thereby improve convenience.
    Type: Grant
    Filed: July 19, 1994
    Date of Patent: January 9, 1996
    Assignee: Fujitsu Limited
    Inventors: Hirohiko Mochizuki, Yoshihiro Takemae, Yukinori Kodama, Makoto Yanagisawa, Katsumi Shigenobu
  • Patent number: 5455803
    Abstract: A semiconductor memory device includes a memory cell array, an address part for supplying address signals to the memory cell array, a read/write part for reading data from the memory cell array and writing data into the memory cell array, and an internal clock signal generating circuit for generating an internal clock signal from an external clock signal. The internal clock signal has a cycle with an active-level portion of constant duration independent of a frequency of the external clock signal and is output, as a timing signal, to predetermined structural parts of the address part and/or the read/write part.
    Type: Grant
    Filed: April 25, 1994
    Date of Patent: October 3, 1995
    Assignee: Fujitsu Limited
    Inventor: Yukinori Kodama
  • Patent number: 5384726
    Abstract: A semiconductor memory device includes a memory cell array in which a number of sense amplifiers are provided, a plurality of segmented drive lines each connected to a group of sense amplifiers for driving the same, each of the segmented drive lines being formed of first and second drive line segments forming a pair, and a number of trunks for supplying electric power to the segmented drive lines. Each of the trunks includes a first conductor strip extending from a first side of the memory cell array toward a second side for connection to a plurality of the first drive line segments upon crossing the same, and a second conductor strip extending from the second side of the memory cell array toward the first side for connection to a plurality of the second drive line segments upon crossing the same.
    Type: Grant
    Filed: February 8, 1994
    Date of Patent: January 24, 1995
    Assignee: Fujitsu Limited
    Inventors: Hiroyoshi Tomita, Makoto Yanagisawa, Yukinori Kodama
  • Patent number: 5353257
    Abstract: In a word line driving circuit coupled to a word line of a memory cell array of a semiconductor memory device, a first transistor has a first terminal receiving an input signal based on a row address signal applied to the semiconductor memory device, a second terminal, and a control terminal receiving a first timing signal. A second transistor having a first terminal receiving a second timing signal, a second terminal connected to the word line, and a control terminal connected to the second terminal of the first transistor. A third transistor has a first terminal connected to the second terminal of the second transistor, a second terminal set at a predetermined potential, and a control terminal receiving a third timing signal. The first transistor has a threshold voltage less than that of at least one of the second and third transistors.
    Type: Grant
    Filed: February 11, 1993
    Date of Patent: October 4, 1994
    Assignee: Fujitsu Limited
    Inventors: Makoto Yanagisawa, Yukinori Kodama
  • Patent number: 5327387
    Abstract: A dynamic random access memory comprises a CBR refresh detection unit for detecting a commencement of a CBR refreshing cycle and a control signal generation unit for deactivating data output during the CBR cycle, both of the CBR refresh detection unit and the control signal generation unit being supplied with a /RAS signal and a /CAS signal simultaneously, wherein the dynamic random access memory further comprises a CBR refresh control unit supplied with an output of the CBR refresh detection unit and further with an output of the control signal generation unit for producing a control signal during the CBR refreshing cycle such that the control signal is produced in response to the leading edge of the /RAS signal and terminated in response to the trailing edge of the /CAS signal.
    Type: Grant
    Filed: November 5, 1992
    Date of Patent: July 5, 1994
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Akira Sugiura, Yukinori Kodama
  • Patent number: 5319607
    Abstract: The present invention relates to a semiconductor unit including a delay circuit used for an address transition detecting circuit in a storage, wherein a change of an address is detected and, accordingly, an access address in a memory cell is altered. The present invention aims at ensuring extending an address signal even though that of a short pulse width is provided, and at outputting an address transition detection signal of a predetermined pulse width, thereby stabilizing the operation of the circuit and improving its reliability. The present invention includes a second address extending circuit having a complementary transistor circuit, a capacitor connected to the output part of the complementary transistor circuit, and a resistor serially connected between a pair of complementary transistors.
    Type: Grant
    Filed: November 18, 1991
    Date of Patent: June 7, 1994
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Yasuhiro Fujii, Hirohiko Mochizuki, Yukinori Kodama, Akira Sugiura
  • Patent number: 5291447
    Abstract: A semiconductor memory device includes a memory cell array including a plurality of memory cells provided in the form of a matrix along a plurality of word lines and a plurality of pairs of bit lines, a plurality of sense amplifiers operatively connected to the plurality of pairs of bit lines, and a sense amplifier control unit operatively connected to the plurality of sense amplifiers. When one of the plurality of memory cells is selected and data writing is carried out to the selected memory cell, the sense amplifier control unit selectively inactivates only a sense amplifier corresponding to the selected memory cell among the plurality of sense amplifiers. Thus, it is possible to remove useless dissipation of write current in the data write operation to thereby decrease the dissipated power, while realizing a high speed write operation.
    Type: Grant
    Filed: July 29, 1992
    Date of Patent: March 1, 1994
    Assignee: Fujitsu Limited
    Inventors: Yukinori Kodama, Yasuhiro Fujii
  • Patent number: 4989182
    Abstract: A dynamic random access memory includes a dummy word line which has an electrical characteristic identical to that of an actual word line. The dummy word line is charged up and is then discharged as in case of the actual word line. A latched row address in a row address latch circuit is reset when the potential of the dummy word line becomes equal to a predetermined low potential due to the discharge operation for the dummy word line.
    Type: Grant
    Filed: October 6, 1988
    Date of Patent: January 29, 1991
    Assignee: Fujitsu Limited
    Inventors: Hirohiko Mochizuki, Tsuyoshi Ohira, Yukinori Kodama, Meiko Kobayashi, Takaaki Furuyama