Patents by Inventor Keiichi Higeta

Keiichi Higeta 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: 20050013160
    Abstract: Disclosed herein is a semiconductor memory device having a memory array comprising CMOS flip-flop circuit type memory cells, which is capable of improving a noise margin, making a read rate fast and reducing power consumption. In the semiconductor memory device, an operating voltage of the memory cell is set higher than an operating voltage of each of peripheral circuits. Threshold voltages of MOS transistors that constitute the memory cell, are set higher than those of MOS transistors constituting the peripheral circuit. A gate insulting film for the MOS transistors that constitute the memory cell, is formed so as to be regarded as thicker than a gate insulting film for the MOS transistors constituting the peripheral circuit when converted to an insulating film of the same material. Further, a word-line selection level and a bit-line precharge level are set identical to the level of the operating voltage of the peripheral circuit.
    Type: Application
    Filed: August 13, 2004
    Publication date: January 20, 2005
    Inventors: Keiichi Higeta, Shigeru Nakahara, Hiroaki Nambu
  • Publication number: 20050007170
    Abstract: An asynchronous control circuit and a semiconductor integrated circuit achieving asynchronous operation and no limitation on the number of ports are offered. In an asynchronous control circuit, by being activated corresponding to at least one access request by acknowledging a plurality of access request signals generated asynchronously to each other and a plurality of input signals corresponding to each of the above-mentioned plurality of access requests, selecting one access request from one or more access requests in the activation mode, acknowledging an input signal corresponding thereto, transmitting the input signal to a memory, acknowledging the input signal corresponding to a non-executed access request after the end the operation corresponding to the input signal, and accessing the aforementioned memory circuit.
    Type: Application
    Filed: July 7, 2004
    Publication date: January 13, 2005
    Inventors: Shigeru Nakahara, Keiichi Higeta, Takahiro Kawata
  • Publication number: 20050002224
    Abstract: A semiconductor integrated circuit device endowed with memory circuits achieving high operation margin and low energy consumption with high speed and high integration. Composing a memory cell with a MOSFET having a first threshold voltage corresponding to a first voltage and supplying a selection signal corresponding to said first voltage to a word line by a word driver driven at said first voltage. Corresponding to a second voltage smaller than said first voltage, forming a selection signal sending to said word driver by a decoder comprising MOSFET with a second threshold voltage smaller than said first voltage, operating at said first voltage, and installing a first level shifting circuit including inverter circuits that form a selection signal corresponding to said first voltage by receiving a selection signal corresponding to said second voltage. Thereby, high operation margin and low energy consumption with high speed and high integration can be achieved.
    Type: Application
    Filed: May 14, 2004
    Publication date: January 6, 2005
    Inventors: Takahiro Kawata, Shigeru Nakahara, Keiichi Higeta
  • Patent number: 6826109
    Abstract: The invention provides a semiconductor integrated circuit device on which a RAM macro capable of selecting an operation mode adapted to improved ease of use, response, or low power consumption or selecting an input setup value is mounted. In a first operation mode of a RAM macro, a timing of receiving an input signal is set as a first timing. In a second operation mode, a timing of receiving an input signal is set to a second timing later than the first timing. In a semiconductor integrated circuit device including an input circuit for receiving an input signal and a decoder circuit for decoding an output signal of the input circuit, the input circuit is activated on the basis of a first signal and the decoder circuit is activated on the basis of a second signal.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: November 30, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Shigeru Nakahara, Satoshi Iwahashi, Takeshi Suzuki, Keiichi Higeta, Kazuo Kanetani
  • Patent number: 6807115
    Abstract: In a dynamic-type semiconductor integrated circuit in which precharge and evaluation operations are preformed per cycle, an IDDQ test and a light detection test can be conducted during an evaluation period for facilitating diagnosis and failure analysis so as to increase test accuracy. The dynamic-type semiconductor integrated circuit operates in a normal operation mode or a test mode, wherein a switch therebetween is triggered by a mode selection signal. In the normal operation mode, the pulse width of an internal activation signal is controlled to be constant, i.e., invariable with an operation cycle time length. In the test mode, the pulse width of the internal activation signal is controlled to vary according to an operation cycle time length.
    Type: Grant
    Filed: February 10, 2003
    Date of Patent: October 19, 2004
    Assignees: Renesas Technology Corporation, Hitachi Device Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Fumihiko Arakawa, Takeshi Kusunoki, Keiichi Higeta
  • Patent number: 6795368
    Abstract: The present invention provides a novel semiconductor integrated circuit device equipped with memory circuits, high-speed memories and large memory capacity memory circuits, which enables speeding up and facilitation of timing settings.
    Type: Grant
    Filed: December 15, 2003
    Date of Patent: September 21, 2004
    Assignee: Renesas Technology Corp.
    Inventors: Satoshi Iwahashi, Shigeru Nakahara, Takeshi Suzuki, Keiichi Higeta
  • Patent number: 6791895
    Abstract: A semiconductor memory device having a memory array comprising CMOS flip-flop circuit type memory cells, which is capable of improving a noise margin, making a read rate fast and reducing power consumption. In the semiconductor memory device, an operating voltage of the memory cell is set higher than an operating voltage of each of peripheral circuits. Threshold voltages of MOS transistors that constitute the memory cell, are set higher than those of MOS transistors constituting the peripheral circuit. A gate insulting film for the MOS transistors that constitute the memory cell, is formed so as to be regarded as thicker than a gate insulting film for the MOS transistors constituting the peripheral circuit when converted to an insulating film of the same material. Further, a word-line selection level and a bit-line precharge level are set identical to the level of the operating voltage of the peripheral circuit.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: September 14, 2004
    Assignee: Renesas Technology Corporation
    Inventors: Keiichi Higeta, Shigeru Nakahara, Hiroaki Nambu
  • Publication number: 20040170044
    Abstract: There is provided a semiconductor integrated circuit device which has realized high speed operation, high integration density and highly efficient layout of the RAM macro, in which a memory array which is divided into four sections in the X and Y coordinates directions is disposed, a first input circuit for receiving a signal which requires optimization for a signal delay is disposed to the center of such four memory arrays, a second input circuit for receiving a data input and control signals thereof is disposed to the center of Y coordinate corresponding to the extending direction of the word line and a signal line for transferring an input signal from the external circuit of the RAM macro to the first and second input circuits is formed using an upper layer wiring for the wiring to form the memory array.
    Type: Application
    Filed: March 4, 2004
    Publication date: September 2, 2004
    Applicants: Renesas Technology Corporation, Hitachi ULSI Systems Co., Ltd.
    Inventors: Takao Saotome, Takeshi Suzuki, Hiroyuki Tanaka, Shigeru Nakahara, Keiichi Higeta
  • Publication number: 20040169527
    Abstract: To speed up the operation of a decoder circuit, reduce the power consumption of the decoder circuit and increase the cycle, each circuit such as a buffer, a predecoder and a main decoder in the decoder circuit is composed by a semiconductor logic circuit wherein the number of columns of transistors for pulling down at an output node is small even if the number of inputs is many and the true and a complementary output signal having approximately the same delay time are acquired and the output pulse length of each circuit in the decoder circuit is reduced.
    Type: Application
    Filed: January 12, 2004
    Publication date: September 2, 2004
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Keiichi Higeta, Kunihiko Yamaguchi, Fumihiko Arakawa
  • Publication number: 20040159882
    Abstract: To reduce the width of isolation between the first and second p channel MIS•FETs driven by different voltages, a first p channel MIS•FET driven by a first supply voltage and a second p channel MIS•FET driven by a second supply voltage higher than the first supply voltage are arranged in the same n well of the same semiconductor substrate, and the second supply voltage is supplied as a common well bias voltage to the n well.
    Type: Application
    Filed: February 6, 2004
    Publication date: August 19, 2004
    Inventors: Takahiro Kawata, Shigeru Nakahara, Keiichi Higeta
  • Patent number: 6779144
    Abstract: A semiconductor integrated circuit device includes a test circuit including a first latch circuit for holding a test pattern input to an electronic circuit operating in accordance with a clock signal and a second latch circuit for holding the output signal of the electronic circuit corresponding to the test pattern. In the test circuit, the clock signal having a frequency higher than the noise frequency generated in the power line at the time of starting to supply the clock signal to the electronic circuit is continuously supplied to the electronic circuit and the test circuit, while at the same time performing, in accordance with the clock signal in a period longer than the period of the clock signal, the operation of inputting the test pattern to the first latch circuit and the operation of outputting the output signal held in the second latch circuit.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: August 17, 2004
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventors: Hideki Hayashi, Keiichi Higeta, Shigeru Nakahara
  • Publication number: 20040105339
    Abstract: A semiconductor memory device comprises a memory-cell array for storing data, a peripheral circuit for carrying out an operation to read out or write data from or into the memory-cell array, read clock generation circuits (111, 113 and 115) each used for generating a read clock signal to be supplied to the peripheral circuit in the operation to read out data from the memory-cell array, write clock generation circuits (112, 114 and 116) each used for generating a write clock signal to be supplied to the peripheral circuit in the operation to write data into the memory-cell array. Since the pulse widths of the clock signals in read and writes are adjusted individually, margin insufficiencies of the pulse widths can be evaluated and results of the evaluation can be fed back to a design phase for, among other purposes, correction of a layout.
    Type: Application
    Filed: November 25, 2003
    Publication date: June 3, 2004
    Inventors: Satoshi Iwahashi, Keiichi Higeta
  • Patent number: 6727532
    Abstract: There is provided a semiconductor integrated circuit device which has realized high speed operation, high integration density and highly efficient layout of the RAM macro, in which a memory array which is divided into four sections in the X and Y coordinates directions is disposed, a first input circuit for receiving a signal which requires optimization for a signal delay is disposed to the center of such four memory arrays, a second input circuit for receiving a data input and control signals thereof is disposed to the center of Y coordinate corresponding to the extending direction of the word line and a signal line for transferring an input signal from the external circuit of the RAM macro to the first and second input circuits is formed using an upper layer wiring for the wiring to form the memory array.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: April 27, 2004
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventors: Takao Saotome, Takeshi Suzuki, Hiroyuki Tanaka, Shigeru Nakahara, Keiichi Higeta
  • Patent number: 6717877
    Abstract: A semiconductor integrated circuit device includes a first variable delay circuit which delays a timing signal for activating a sense amplifier which is supplied with a signal read out from a memory array and amplifies the signal so that a timing difference between a dummy signal read out from a dummy memory cell and the timing signal of the sense amplifier is detected by a detection circuit to be made small in accordance with an output of the detection circuit, and a second variable delay circuit which adjusts a relative timing difference between the dummy signal and the timing signal of the sense amplifier.
    Type: Grant
    Filed: January 8, 2002
    Date of Patent: April 6, 2004
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Takeshi Suzuki, Shigeru Nakahara, Keiichi Higeta, Takeshi Kusunoki
  • Publication number: 20040057329
    Abstract: Disclosed herein is a semiconductor memory device having a memory array comprising CMOS flip-flop circuit type memory cells, which is capable of improving a noise margin, making a read rate fast and reducing power consumption. In the semiconductor memory device, an operating voltage of the memory cell is set higher than an operating voltage of each of peripheral circuits. Threshold voltages of MOS transistors that constitute the memory cell, are set higher than those of MOS transistors constituting the peripheral circuit. A gate insulting film for the MOS transistors that constitute the memory cell, is formed so as to be regarded as thicker than a gate insulting film for the MOS transistors constituting the peripheral circuit when converted to an insulating film of the same material. Further, a word-line selection level and a bit-line precharge level are set identical to the level of the operating voltage of the peripheral circuit.
    Type: Application
    Filed: September 29, 2003
    Publication date: March 25, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Keiichi Higeta, Shigeru Nakahara, Hiroaki Nambu
  • Patent number: 6707751
    Abstract: The present invention provides a novel semiconductor integrated circuit device equipped with memory circuits, high-speed memories and large memory capacity memory circuits, which enables speeding up and facilitation of timing settings.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: March 16, 2004
    Assignee: Renesas Technology Corporation
    Inventors: Satoshi Iwahashi, Shigeru Nakahara, Takeshi Suzuki, Keiichi Higeta
  • Patent number: 6677782
    Abstract: To speed up the operation of a decoder circuit, reduce the power consumption of the decoder circuit and increase the cycle, each circuit such as a buffer, a predecoder and a main decoder in the decoder circuit is composed by a semiconductor logic circuit wherein the number of columns of transistors for pulling down at an output node is small even if the number of inputs is many and the true and a complementary output signal having approximately the same delay time are acquired and the output pulse length of each circuit in the decoder circuit is reduced. According to the present invention, the operation of the decoder circuit can be sped up, the power consumption can be reduced, the cycles can be increased and in a semiconductor memory for example, the reduction of access time and power consumption and the increase of the cycles are enabled.
    Type: Grant
    Filed: April 24, 2001
    Date of Patent: January 13, 2004
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Keiichi Higeta, Kunihiko Yamaguchi, Fumihiko Arakawa
  • Patent number: 6670201
    Abstract: A manufacturing method of a semiconductor device capable of obtaining highly reliable semiconductor devices with the realization of high integration and high speed intended is provided. During processes after a desired circuit including a CMOS static type circuit is formed on a semiconductor substrate until product shipment, a first operation of feeding a predetermined input signal to the circuit and retrieving a first output signal corresponding to it and a second operation of giving an operating condition of increasing an ON resistance value of MOSFETs constituting the CMOS static type circuit and retrieving a second output signal corresponding to the condition are conducted, and a testing step of determining a failure by the first output signal varying from the second output signal.
    Type: Grant
    Filed: August 28, 2001
    Date of Patent: December 30, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Masaki Kouno, Masato Hamamoto, Atsushi Wakahara, Hideyuki Takahashi, Keiichi Higeta, Mitsugu Kusunoki, Kazutaka Mori
  • Patent number: 6657887
    Abstract: A semiconductor memory device having a memory array comprising CMOS flip-flop circuit type memory cells capable of improved noise margin, faster read rate and reduced power consumption is formed using an operating voltage of the memory cell that is set higher than an operating voltage of each of peripheral circuits. Threshold voltages of MOS transistors that constitute the memory cell, are set higher than those of MOS transistors constituting the peripheral circuit. A gate insulting film for the MOS transistors that constitute the memory cell, is formed so as to be regarded as thicker than a gate insulting film for the MOS transistors constituting the peripheral circuit when converted to an insulating film of the same material. Further, a word-line selection level and a bit-line precharge level are set identical to the level of the operating voltage of the peripheral circuit.
    Type: Grant
    Filed: July 22, 2002
    Date of Patent: December 2, 2003
    Assignee: Renesas Technology Corporation
    Inventors: Keiichi Higeta, Shigeru Nakahara, Hiroaki Nambu
  • Patent number: 6617610
    Abstract: In a dynamic-type semiconductor integrated circuit in which precharge and evaluation operations are preformed per cycle, an IDDQ test and a light detection test can be conducted during an evaluation period for facilitating diagnosis and failure analysis so as to increase test accuracy. The dynamic-type semiconductor integrated circuit operates in a normal operation mode or a test mode, wherein a switch therebetween is triggered by a mode selection signal. In the normal operation mode, the pulse width of an internal activation signal is controlled to be constant, i.e., invariable with an operation cycle time length. In the test mode, the pulse width of the internal activation signal is controlled to vary according to an operation cycle time length.
    Type: Grant
    Filed: December 13, 2001
    Date of Patent: September 9, 2003
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Fumihiko Arakawa, Takeshi Kusunoki, Keiichi Higeta