Patents by Inventor Tatsuyuki Ohta

Tatsuyuki Ohta 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: 5619455
    Abstract: A pipeline-operating type memory system is arranged to have a first input unit for receiving a selector address signal for selecting data; a second input unit for receiving at least an address strobe signal, an X address signal and a Y address signal for selecting data; a first unit for receiving the X address signal and the Y address signal, latching these signals utilizing a first clock signal, and continuously outputting at least either of the X and the Y address signals until these address signals are unlatched; and a second unit for latching a selector address data signal output from the first input unit utilizing the first clock signal, and continuously and selectively outputting at least either of the address signal until the signal is unlatched. The memory system operates to transfer data in a manner to suit the pipeline operating cycle at a normal operating mode and at a fast page mode.
    Type: Grant
    Filed: March 23, 1993
    Date of Patent: April 8, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Noboru Akiyama, Yuji Yokoyama, Tatsuyuki Ohta, Kunihiko Suzuki, Yutaka Kobayashi
  • Patent number: 5602782
    Abstract: A pipeline-operating type memory system is arranged to have a first input unit for receiving a selector address signal for selecting data, a second input unit for receiving at least an address strobe signal, an X address signal and a Y address signal for selecting data; a first unit for receiving the X address signal and the Y address signal, latching these signals utilizing a first clock signal, and continuously outputting at least either of the X and the Y address signals until these address signals are unlatched; and a second unit for latching a selector address data signal output from the first input unit utilizing the first clock signal, and continuously and selectively outputting at least either of the address signal until the signal is unlatched. The memory system operates to transfer data in a manner to suit the pipeline operating cycle at a normal operating mode and at a fast page mode.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: February 11, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Noboru Akiyama, Yuji Yokoyama, Tatsuyuki Ohta, Kunihiko Suzuki, Yutaka Kobayashi
  • Patent number: 5506804
    Abstract: A Bi.CMOS semiconductor memory device is provided which includes an arrangement to simultaneously select a plurality of memory cells, followed by using a 3 bit Z addressing arrangement to determine a read or write operation for the simultaneously selected memory cells. To speed up the word line selection, a static selection type operation is used with the word line selecting voltage being greater than signal amplitude of the data lines during the write operation. Also, to speed up the read operation, separate common I/O lines are provided for the read and write operations. Read signals are transmitted as current signals, and then converted to voltage signals for improving reading speed. Also, improved arrangements are provided for resistance structure, logic circuitry, input circuitry, fuse cutting circuitry, drive circuitry, power circuitry, electrostatic protection circuitry, layout structure and testing methods for the semiconductor device.
    Type: Grant
    Filed: November 30, 1993
    Date of Patent: April 9, 1996
    Assignees: Hitachi, Ltd., VLSI Engineering Corp.
    Inventors: Kazumasa Yanagisawa, Tatsuyuki Ohta, Tetsu Udagawa, Kyoko Ishii, Hitoshi Miwa, Atsushi Nozoe, Masayuki Nakamura, Tetsurou Matsumoto, Yoshitaka Kinoshita, Yoshiaki Ouchi, Hiromi Tsukada, Shoji Wada, Kazuo Mihashi, Yutaka Kobayashi, Goro Kitsukawa
  • Patent number: 5373469
    Abstract: A high-speed memory employing the pipeline technique is disclosed, in which the minimum operating cycle time is reduced by use of a latch circuit for a small signal using a bipolar transistor. A small-signal latch circuit operating at a signal smaller than an output signal level is inserted between an amplifier circuit for amplifying the data held in a memory cell circuit and an output buffer circuit. A switch signal is also interposed between the latch circuit and the amplifier circuit, thereby shortening the cycle time.
    Type: Grant
    Filed: May 29, 1992
    Date of Patent: December 13, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Akioka, Noboru Akiyama, Yutaka Kobayashi, Tatsuyuki Ohta, Koyo Katsura
  • Patent number: 5276648
    Abstract: A Bi.CMOS semiconductor memory device is provided which includes an arrangement to simultaneously select a plurality of memory cells, followed by using a 3 bit Z addressing arrangement to determine a read or write operation for the simultaneously selected memory cells. To speed up the word line selection, a static selection type operation is used with the word line selecting voltage being greater than signal amplitude of the data lines during the write operation. Also, to speed up the read operation, separate common I/O lines are provided for the read and write operations. Read signals are transmitted as current signals, and then converted to voltage signals for improving reading speed. Also, improved arrangements are provided for resistance structure, logic circuitry, input circuitry, fuse cutting circuitry, drive circuitry, power circuitry, electrostatic protection circuitry, layout structure and testing methods for the semiconductor device.
    Type: Grant
    Filed: January 8, 1992
    Date of Patent: January 4, 1994
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Kazumasa Yanagisawa, Tatsuyuki Ohta, Tetsu Udagawa, Kyoko Ishii, Hitoshi Miwa, Atsushi Nozoe, Masayuki Nakamura, Tetsurou Matsumoto, Yoshitaka Kinoshita, Yoshiaki Ouchi, Hiromi Tsukada, Shoji Wada, Kazuo Mihashi, Yutaka Kobayashi, Goro Kitsukawa
  • Patent number: 5150325
    Abstract: A Bi.CMOS semiconductor memory device is provided which includes an arrangement to simultaneously select a plurality of memory cells, followed by using a 3 bit Z addressing arrangement to determine a read or write operation for the simultaneously selected memory cells. To speed up the word line selection, a static selection type operation is used with the word line selecting voltage being greater than signal amplitude of the data lines during the write operation. Also, to speed up the read operation, separate common I/O lines are provided for the read and write operations. Read signals are transmitted as curent signals, and then converted to voltage signals for improving reading speed. Also, improved arrangements are provided for resistance structure, logic circuitry, input circuitry, fuse cutting circuitry, drive circuitry, power circuitry, electrostatic protection circuitry, layout structure and testing methods for the semiconductor device.
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: September 22, 1992
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp
    Inventors: Kazumasa Yanagisawa, Tatsuyuki Ohta, Tetsu Udagawa, Kyoko Ishii, Hitoshi Miwa, Atsushi Nozoe, Masayuki Nakamura, Tetsurou Matsumoto, Yoshitaka Kinoshita, Yoshiaki Ouchi, Hiromi Tsukada, Shoji Wada, Kazuo Mihashi, Yutaka Kobayashi, Goro Kitsukawa