Patents by Inventor Yutaka Fukutani

Yutaka Fukutani 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: 6262924
    Abstract: A semiconductor memory device is provided with terminals for receiving a chip enable signal and an address signal, an internal circuit, and an internal control signal generating circuit for generating a predetermined internal control signal which makes an output timing of the semiconductor memory device same regardless of a level of the address signal when the chip enable signal undergoes a transition from an inactive level to an active level. The internal circuit is deactivated in response to the inactive level of the chip enable signal and is activated in response to the active level of the chip enable signal.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: July 17, 2001
    Assignee: Fujitsu Limited
    Inventors: Yutaka Fukutani, Tomohiro Nakayama, Seizi Hirayama, Waichiro Fujieda, Arayama Youji, Atsushi Fujii, Yoshitaka Takahashi, Masanori Nagasawa, Masakazu Kimura, Tutomu Taniguti, Hiroyuki Fujimoto
  • Patent number: 6026052
    Abstract: A semiconductor memory device is provided with terminals for receiving a chip enable signal and an address signal, an internal circuit, and an internal control signal generating circuit for generating a predetermined internal control signal which makes an output timing of the semiconductor memory device same regardless of a level of the address signal when the chip enable signal undergoes a transition from an inactive level to an active level. The internal circuit is deactivated in response to the inactive level of the chip enable signal and is activated in response to the active level of the chip enable signal.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: February 15, 2000
    Assignee: Fujitsu Limited
    Inventors: Yutaka Fukutani, Tomohiro Nakayama, Seizi Hirayama, Waichiro Fujieda, Arayama Youji, Atsushi Fujii, Yoshitaka Takahashi, Masanori Nagasawa, Masakazu Kimura, Tutomu Taniguti, Hiroyuki Fujimoto
  • Patent number: 5831933
    Abstract: A semiconductor memory device is provided with terminals for receiving a chip enable signal and an address signal, an internal circuit, and an internal control signal generating circuit for generating a predetermined internal control signal which makes an output timing of the semiconductor memory device same regardless of a level of the address signal when the chip enable signal undergoes a transition from an inactive level to an active level. The internal circuit is deactivated in response to the inactive level of the chip enable signal and is activated in response to the active level of the chip enable signal.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: November 3, 1998
    Assignee: Fujitsu Limited
    Inventors: Yutaka Fukutani, Tomohiro Nakayama, Seizi Hirayama, Waichiro Fujieda, Arayama Youji, Atsushi Fujii, Yoshitaka Takahashi, Masanori Nagasawa, Masakazu Kimura, Tutomu Taniguti, Hiroyuki Fujimoto
  • Patent number: 5781627
    Abstract: A semiconductor integrated circuit device with a copy-preventive function comprises a memory for storing data to be used by users, an input unit for performing various logical operations on at least one input information fed externally and accessing the memory, an output unit for performing various logical operations on the data at the time of supplying the data from the memory, a judging unit for comparing at least one of the state of the input information, the logical state of the input unit, the logical state of the output unit, and the state of data provided by the output unit with specific judgment information and indicating the result of comparison, and a control unit that when the result indicated by the judging unit reveals that the at least one of the states is consistent with a specific state, acts at least on the output unit so as to prevent data stored in the memory from being supplied normally.
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: July 14, 1998
    Assignee: Fujitsu Limited
    Inventors: Nobuo Ikuta, Kouji Ueno, Kouji Shishido, Yutaka Fukutani, Youji Arayama, Tomohiro Nakayama, Takanori Shiga, Masakazu Kimura, Hiroyuki Fujimoto, Yoshiyuki Fujita
  • Patent number: 5661694
    Abstract: A semiconductor memory device is provided with terminals for receiving a chip enable signal and an address signal, an internal circuit, and an internal control signal generating circuit for generating a predetermined internal control signal which makes an output timing of the semiconductor memory device same regardless of a level of the address signal when the chip enable signal undergoes a transition from an inactive level to an active level. The internal circuit is deactivated in response to the inactive level of the chip enable signal and is activated in response to the active level of the chip enable signal.
    Type: Grant
    Filed: May 3, 1994
    Date of Patent: August 26, 1997
    Assignee: Fujitsu Limited
    Inventors: Yutaka Fukutani, Tomohiro Nakayama, Seizi Hirayama, Waichiro Fujieda, Arayama Youji, Atsushi Fujii, Yoshitaka Takahashi, Masanori Nagasawa, Masakazu Kimura, Tutomu Taniguti, Hiroyuki Fujimoto
  • Patent number: 5600599
    Abstract: An object of the present invention is to improve the output speed of a data signal output circuit having a latch circuit when the supply voltage is low. The data signal output circuit according to the present invention includes a latch circuit; an output circuit; a latch control circuit; an output control circuit; and a supply voltage decrease detection circuit. The latch circuit latches and holds a data signal according to a latch signal output from the latch control circuit. By setting the latch signal to one of two logical states, the latch circuit changes to a through state directly outputting an input data signal. The output circuit changes between a state for outputting a data signal from the latch circuit and a high-impedance state according to an output control signal output from the output control circuit. The supply voltage decrease detection circuit detects whether or not the supply voltage is less than a pre-determined value.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: February 4, 1997
    Assignee: Fujitsu Limited
    Inventors: Tomohiro Nakayama, Yutaka Fukutani, Takanori Shiga, Masakazu Kimura