Patents by Inventor Fumihiko Arakawa

Fumihiko Arakawa 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: 7212744
    Abstract: The invention provides a transceiver circuit for communication that enhances the operation frequency of a synchronous digital circuit up to the maximum frequency of a flip-flop and inhibits the occurrence of jitters. A clock signal synchronized with data at f1/n Hz is converted by a multiplier so that the signal has a frequency of ā€œnā€ times so as to use the clock signal for triggering a flip-flop the operation frequency of which is f1 b/s in the synchronous digital circuit. The multiplier is arranged in the vicinity of the flip-flop triggered by the clock signal of f1 Hz so as to avoid the effect of the deterioration of the operation frequency by interconnect capacitance. The maximum operation frequency of the transceiver circuit determined based upon the operating frequency of the synchronous digital circuit can be enhanced up to the maximum operation frequency of the flip-flop.
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: May 1, 2007
    Assignee: Renesas Technology Corp
    Inventors: Nobuhiro Shiramizu, Kenichi Ohhata, Fumihiko Arakawa, Takeshi Kusunoki
  • Publication number: 20060119970
    Abstract: A write driver circuit capable of controlling the waveform of overshoot of a write current, more specifically, controlling a rise, amplitude, and duration of overshoot (OS) in the waveform of an output current independently of one another. The write driver circuit includes transistors for controlling the rise, amplitude, and duration of OS, an impedance matching unit between the write driver and the load, and a canceller of reflection waves from the head.
    Type: Application
    Filed: December 2, 2005
    Publication date: June 8, 2006
    Inventors: Yoshihiro Hayashi, Fumihiko Arakawa, Takeshi Kusunoki, Satoshi Ueno
  • Patent number: 6998878
    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 includes a semiconductor logic circuit in which 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. With this arrangement, 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, access time and power consumption can be reduced and the cycles can be increased.
    Type: Grant
    Filed: January 12, 2004
    Date of Patent: February 14, 2006
    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: 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
  • 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: 20040151506
    Abstract: The invention provides a transceiver circuit for communication that enhances the operation frequency of a synchronous digital circuit up to the maximum frequency of a flip-flop and inhibits the occurrence of jitters.
    Type: Application
    Filed: January 20, 2004
    Publication date: August 5, 2004
    Applicant: Renesas Technology Corp.
    Inventors: Nobuhiro Shiramizu, Kenichi Ohhata, Fumihiko Arakawa, Takeshi Kusunoki
  • 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: 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
  • Publication number: 20030123309
    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: Application
    Filed: February 10, 2003
    Publication date: July 3, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Fumihiko Arakawa, Takeshi Kusunoki, Keiichi Higeta
  • Publication number: 20020196053
    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: August 29, 2002
    Publication date: December 26, 2002
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Keiichi Higeta, Kunihiko Yamaguchi, Fumihiko Arakawa
  • Patent number: 6438050
    Abstract: A transmission circuit for transmitting a data signal between circuit units through a signal wire. The data signal is transmitted for precharging the signal wire to high potential during a precharge period and discharging it to low potential according to data transmitted during an evaluation period or keeping the signal wire as it is. Latch type Source-Coupled-Logic is configured so that a first node and a second node used as an output terminal to the next stage are respectively charged together to high potential during the precharge period. The second node is discharged according to a potential at the first node during the evaluation period, and the first node is discharged according to a potential on the signal wire. Thus, the operation of discharging the signal wire by the driver circuit can be sped up.
    Type: Grant
    Filed: January 8, 2002
    Date of Patent: August 20, 2002
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Fumihiko Arakawa
  • Publication number: 20020098602
    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: Application
    Filed: December 13, 2001
    Publication date: July 25, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Fumihiko Arakawa, Takeshi Kusunoki, Keiichi Higeta
  • Publication number: 20020057612
    Abstract: A transmission circuit for transmitting a data signal between circuit units through a signal wire. The data signal is transmitted for precharging the signal wire to high potential during a precharge period and discharging it to low potential according to data transmitted during an evaluation period or keeping the signal wire as it is. Latch type Source-Coupled-Logic is configured so that a first node and a second node used as an output terminal to the next stage are respectively charged together to high potential during the precharge period. The second node is discharged according to a potential at the first node during the evaluation period, and the first node is discharged according to a potential on the signal wire. Thus, the operation of discharging the signal wire by the driver circuit can be sped up.
    Type: Application
    Filed: January 8, 2002
    Publication date: May 16, 2002
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Fumihiko Arakawa
  • Patent number: 6369617
    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 include a semiconductor logic circuit wherein the number of columns of transistors for pulling down an output node is small even if the number of inputs is large, and the true output signal 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. By virtue of this arrangement, 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: November 10, 1999
    Date of Patent: April 9, 2002
    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: 6356493
    Abstract: A transmission circuit for transmitting a data signal between circuit units through a signal wire. The data signal is transmitted for precharging the signal wire to high potential during a precharge period and discharging it to low potential according to data transmitted during an evaluation period or keeping the signal wire as it is. Latch type Source-Coupled-Logic as configured so that a first node and a second node used as an output terminal to the next stage are respectively charged together to high potential during the precharge period. The second node is discharged according to potential at the first node during the evaluation period, and the first node is discharged according to a potential on the signal wire. Thus, the operation of discharging the signal wire by the driver circuit can be sped up.
    Type: Grant
    Filed: August 11, 2000
    Date of Patent: March 12, 2002
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Fumihiko Arakawa
  • Publication number: 20020017923
    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: April 24, 2001
    Publication date: February 14, 2002
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Keiichi Higeta, Kunihiko Yamaguchi, Fumihiko Arakawa
  • Patent number: 6337581
    Abstract: Disclosed herein is a transmission circuit for transmitting a data signal between circuit units on a semiconductor integrated circuit through a signal wire. The data signal is transmitted by a driver circuit for precharging the signal wire to a high potential during a precharge period and discharging the signal wire to a low potential according to data to be transmitted during an evaluation period or keeping the signal wire at a high potential as floating as it is.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: January 8, 2002
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Fumihiko Arakawa
  • Patent number: 6333881
    Abstract: One of the factors determining cycle time of an SRAM is recovery time of a bit line after writing. When the size of a precharge PMOS transistor is increased to shorten the recovery time, delay time which is caused by making the precharge PMOS transistors non-conductive at the time of read operation, that is, access time increases. To avoid this, a semiconductor memory is provided with a second precharge circuit in addition to the conventional bit line precharge circuit. The second precharge circuit operates upon detection of completion of writing and stops operation when it detects that the bit line is precharged to a high potential. Consequently, the recovery time after write operation is shortened and the cycle time is reduced without increasing the access time.
    Type: Grant
    Filed: June 28, 2000
    Date of Patent: December 25, 2001
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Takeshi Kusunoki, Fumihiko Arakawa, Hiroaki Nambu, Kazuo Kanetani, Kaname Yamasaki
  • Patent number: 6229745
    Abstract: A semiconductor memory in accordance with the present invention includes a sense amplifier composed of a plurality of MOS transistors. When the sense amplifier is on standby, a first control circuit brings an input signal of the sense amplifier to zero. A second control circuit uses voltages developed because of an offset voltage occurring in the sense amplifier to feed back the potentials in the wells of the MOS transistors so that the offset voltage will be nullified. When the offset voltage occurring in the sense amplifier is nullified, a delay time required by the sense amplifier is shortened. This results in the high-speed semiconductor memory.
    Type: Grant
    Filed: April 26, 2000
    Date of Patent: May 8, 2001
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Hiroaki Nambu, Kazuo Kanetani, Kaname Yamasaki, Fumihiko Arakawa, Takeshi Kusunoki
  • Patent number: 6075729
    Abstract: A semiconductor memory has a plurality of word lines a plurality of bit line pairs and a plurality of memory cells formed at intersection points between the word lines and the bit line pairs. A word decoder generates a word line select signal upon receipt of an address signal and a bit decoder generates a bit line select signal on receiving the address signal. A bit line load circuit receives a signal current from the applicable memory cell, a sense circuit detects an output signal from the bit line load circuit, and a bit line pull-down circuit and a bit line recovery circuit drives the applicable bit lines upon writing data to the memory cell in question.
    Type: Grant
    Filed: September 1, 1998
    Date of Patent: June 13, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Kenichi Ohhata, Fumihiko Arakawa, Takeshi Kusunoki, Hiroaki Nambu, Kazuo Kanetani, Kaname Yamasaki, Keiichi Higeta