Patents by Inventor Masakazu Yamashina

Masakazu Yamashina 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: 7366821
    Abstract: A memory system has a memory controller and a plurality of memories. The plurality of memories are connected via a switch to an end of a bus, which is connected to the memory controller, wherein the plurality of memories are controlled by the switch. By suppressing reflection and loads on the bus, a higher data transmission speed can be obtained.
    Type: Grant
    Filed: June 20, 2001
    Date of Patent: April 29, 2008
    Assignee: NEC Corporation
    Inventors: Muneo Fukaishi, Masato Motomura, Yoshiharu Aimoto, Masakazu Yamashina
  • Publication number: 20030163606
    Abstract: A memory system has a memory controller and a plurality of memories. The plurality of memories are connected via a switch to an end of a bus, which is connected to the memory controller, wherein the plurality of memories are controlled by the switch. By suppressing reflection and loads on the bus, a higher data transmission speed can be obtained.
    Type: Application
    Filed: March 18, 2003
    Publication date: August 28, 2003
    Inventors: Mueo Fukaishi, Masato Motomura, Yoshiharu Aimoto, Masakazu Yamashina
  • Patent number: 6229360
    Abstract: A first latching circuit transferring an input signal from the input terminal to the output terminal for a predetermined period in response to a level transition timing of one direction of a clock signal input to the clock terminal, and maintaining a signal condition of the output terminal in the remaining period, and a second latching circuit transferring an input signal from the input terminal to the output terminal for a predetermined period in response to a level transition timing of the other direction of the clock signal input to the clock terminal, and maintaining a signal condition of the output terminal in the remaining period, are provided. A desired logic circuit is connected between the first and second latching circuits. By synchronously operating the first and second latching circuits by supplying a common clock signal, a clock synchronization circuit not influenced by fluctuation of the device, fluctuation of temperature or power source can be formed.
    Type: Grant
    Filed: September 9, 1998
    Date of Patent: May 8, 2001
    Assignee: NEC Corporation
    Inventors: Masayuki Mizuno, Masakazu Yamashina
  • Patent number: 6094068
    Abstract: A CMOS logic circuit including (a) a PMOS transistor, (b) an NMOS transistor, (c) a first coupling capacitor electrically connected only between a gate and a substrate of the PMOS transistor, and (d) a second coupling capacitor electrically connected between a gate and drain of the NMOS transistor, wherein the PMOS and NMOS transistors include substrate voltages which are made higher than associated reference voltages during rising edges of signals transmitted to the gates, and made lower than the associated reference voltages during falling edges of the signals. The gates of the PMOS and NMOS transistors are electrically connected to each other, drains of the PMOS and NMOS transistors are electrically connected to each other, and an input signal is introduced into the electrically connected gates, and an output signal is taken through the electrically connected drains.
    Type: Grant
    Filed: June 18, 1998
    Date of Patent: July 25, 2000
    Assignee: NEC Corporation
    Inventors: Masahiro Nomura, Masakazu Yamashina
  • Patent number: 5801570
    Abstract: A plurality of MOS transistors connected to each other at a substrate electrode thereof to have a substrate potential are deviation-compensated by a combination of a power source having a power source potential independent from the substrate potential, a power supply line connected to a source electrode of each of the MOS transistors, a sample circuit composed of a sampled one of the MOS transistors, detection circuitry for detecting an action of the sample circuit to provide a detection signal representing a difference between the detected action of the sample circuit and a reference action therefor, and a voltage generator connected between the power source and the power supply line, the voltage generator generating a voltage depending on the detection signal.
    Type: Grant
    Filed: May 20, 1997
    Date of Patent: September 1, 1998
    Assignee: NEC Corporation
    Inventors: Masayuki Mizuno, Masakazu Yamashina
  • Patent number: 5742195
    Abstract: A plurality of MOS transistors connected to each other at a substrate electrode thereof to have a substrate potential are deviation-compensated by a combination of a power source having a power source potential independent from the substrate potential, a power supply line connected to a source electrode of each of the MOS transistors, a sample circuit composed of a sampled one of the MOS transistors, detection circuitry for detecting an action of the sample circuit to provide a detection signal representing a difference between the detected action of the sample circuit and a reference action therefor, and a voltage generator connected between the power source and the power supply line, the voltage generator generating a voltage depending on the detection signal.
    Type: Grant
    Filed: February 2, 1996
    Date of Patent: April 21, 1998
    Assignee: NEC Corporation
    Inventors: Masayuki Mizuno, Masakazu Yamashina
  • Patent number: 5686853
    Abstract: The present invention provides a driver circuitry having a single input terminal for receiving an input signal of binary digits consisting of high and low levels, and at least first and second output terminals, wherein the input signal is varied almost linearly in a first time period so as to be shifted between high and low levels, the driver circuitry comprises first and second control circuits. The first control circuit is coupled to the input terminal for receiving the input signal. The first control circuit is also coupled to the first output terminal for outputting a first output signal of binary digits via the first output terminal. The first control circuit is biased between a high voltage line which supplies a high level of voltage and a low voltage line which supplies a low level of voltage.
    Type: Grant
    Filed: December 29, 1995
    Date of Patent: November 11, 1997
    Assignee: NEC Corporation
    Inventors: Tomofumi Iima, Masakazu Yamashina, Masayuki Mizuno
  • Patent number: 5585754
    Abstract: An integrated digital circuit includes an oscillation circuit comprising basic gate circuits having the number of stages proportional to the number of gates existing in the critical path of a synchronized circuit network and capable of controlling an oscillating frequency by at least one control signal line. A synchronized circuit network constructed with basic gate circuits capable of controlling the delay time by at least one control signal line operates synchronously by an oscillation signal transfer line. A control circuit controls the oscillation circuit and the synchronized circuit network using the control signal line so that the frequency of signal input from an externally input signal line is equalized with the frequency of signal from the oscillation circuit.
    Type: Grant
    Filed: April 4, 1994
    Date of Patent: December 17, 1996
    Assignee: NEC Corporation
    Inventors: Masakazu Yamashina, Masayuki Mizuno
  • Patent number: 5559461
    Abstract: A drive circuit includes first and second circuit sections. The first circuit section maintains, during an initial stage of a transient period of an input signal, its output level before the signal transition and supplies after the transient period an output signal responsive to the signal transition. The second circuit section has a first circuit portion receiving the input signal and a second circuit portion, responsive to the input signal, and the output of the first circuit section, to accelerate the signal transition of the first circuit portion. Signal delay in a signal transition due to a large parasitic capacitance and resistance can be recovered by the drive circuit. The drive circuit has a large noise margin and operates at a high-speed and in a wide frequency range.
    Type: Grant
    Filed: June 27, 1995
    Date of Patent: September 24, 1996
    Assignee: NEC Corporation
    Inventors: Masakazu Yamashina, Youichi Koseki, Masayuki Mizuno
  • Patent number: 4985861
    Abstract: For improvement in processing speed, a high-speed digital signal processor has a feedback loop from a register which stores the calculating result produced by a Signed Digit (SD) arithmetic unit to one of the input ports of the SD arithmetic unit. The SD arithmetic unit executes an arithmetic operation on an input digital signal and the arithmetic result is formed of both signed digit numbers without the need to convert the calculation result represented by an SD number into a binary number.
    Type: Grant
    Filed: January 27, 1989
    Date of Patent: January 15, 1991
    Assignee: NEC Corporation
    Inventors: Masakazu Yamashina, Hachiro Yamada, Tadayoshi Enomoto
  • Patent number: 4849921
    Abstract: An arithmetic circuit has a first subtracter receiving first and second input signals which are composed of a plurality of bits and operative to output a first output signal representative of the first input signal minus the second input signal, and a second subtracter receiving the first and second input signals so as to output a second output signal representative of the second input signal minus the first input signal. A selector receives the first and second output signals and operates in response to one of the first and second output signals so as to alternately output the first and second output signals.
    Type: Grant
    Filed: June 19, 1986
    Date of Patent: July 18, 1989
    Assignee: NEC Corporation
    Inventors: Masaaki Yasumoto, Tadayoshi Enomoto, Masakazu Yamashina