Patents by Inventor Kazuo Mihashi

Kazuo Mihashi 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: 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: 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
  • Patent number: 4941128
    Abstract: A dynamic type RAM is provided wherein the level of a precharge control signal supplied to a gate of a precharge MOSFET to precharge complementary data lines to a half level is made the half level during a period from the memory access until the selection of the word line, at the latest. Also, the precharge control signal, corresponding to a memory mat selected according to establishing of an address, is set to a low level, while the precharge control signal corresponding to a non-selective memory mat is set to a high level.
    Type: Grant
    Filed: April 25, 1988
    Date of Patent: July 10, 1990
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Shouji Wada, Nobuo Komatsu, Mitsuhiro Takano, Sinichi Miyatake, Kazuo Mihashi, Hiromi Tsukada