Patents by Inventor Masamichi Fujito

Masamichi Fujito 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: 6542411
    Abstract: A nonvolatile memory includes a control register (CRG) for providing instructions as to basic operations such as writing, erasing, reading, etc., a boosted voltage attainment detecting circuit for detecting whether a voltage boosted by a booster circuit has reached a desired level, a circuit which counts the time required to apply each of write and erase voltages, and a circuit which detects the completion of the writing or erasing. Respective operations are automatically advanced by simple setting of the operation instructions to the control register. After the completion of the operations, an end flag (FLAG) provided within the control register is set to notify the completion of the writing or erasing.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: April 1, 2003
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Hiroyuki Tanikawa, Toshihiro Tanaka, Yutaka Shinagawa, Yoshiki Kawajiri, Masamichi Fujito
  • Publication number: 20030016566
    Abstract: A semiconductor device whose characteristics are highly reliably regulated for circuits whose desired characteristics need to be realized without being affect by unevenness in device characteristics is to be provided. A replica MOS transistor for amperage measurement connected to an external measuring terminal is provided. A delay circuit and other circuits whose desired characteristics are to be realized have a constant current source MOS transistor formed in the same process as the replica MOS transistor, and a trimming voltage vtri is commonly applied to the respective gates of the constant current source MOS transistor and the replica MOS transistor. Trimming data determined on the basis of an amperage measured from the external measuring terminal are stored into a memory means such as an electrically rewritable non-volatile memory or the like. The trimming data determine the trimming voltage vtri.
    Type: Application
    Filed: September 20, 2002
    Publication date: January 23, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Takashi Yamaki, Kan Takeuchi, Mitsuru Hiraki, Toshihiro Tanaka, Yutaka Shinagawa, Masamichi Fujito
  • Patent number: 6480418
    Abstract: The present invention proposes a non-volatile semiconductor storage, comprising a plurality of main bit lines, a plurality of sub bit lines connected to the main bit lines, and a plurality of memory cell arrays, each including a plurality of non-volatile semiconductor memory cells disposed like an array. Each of those memory cells has a source terminal, a drain terminal, and a control gate, and each source-drain path is connected to a sub bit line. Between a main bit line and a sub bit line connected to the main bit line is disposed the source-drain path of a first transistor, and the source-drain path of a second transistor is connected to the sub bit line.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: November 12, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Toshihiro Tanaka, Yutaka Shinagawa, Kazuyoshi Shiba, Kazufumi Suzukawa, Masamichi Fujito, Takayuki Oshima, Sonoko Abe, Kiyoshi Matsubara
  • Patent number: 6477090
    Abstract: A semiconductor device whose characteristics are highly reliably regulated for circuits whose desired characteristics need to be realized without being affect by unevenness in device characteristics is to be provided. A replica MOS transistor for amperage measurement connected to an external measuring terminal is provided. A delay circuit and other circuits whose desired characteristics are to be realized have a constant current source MOS transistor formed in the same process as the replica MOS transistor, and a trimming voltage vtri is commonly applied to the respective gates of the constant current source MOS transistor and the replica MOS transistor. Trimming data determined on the basis of an amperage measured from the external measuring terminal are stored into a memory means such as an electrically rewritable non-volatile memory or the like. The trimming data determine the trimming voltage vtri.
    Type: Grant
    Filed: August 28, 2001
    Date of Patent: November 5, 2002
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Takashi Yamaki, Kan Takeuchi, Mitsuru Hiraki, Toshihiro Tanaka, Yutaka Shinagawa, Masamichi Fujito
  • Publication number: 20020048193
    Abstract: The invention includes a control register (CRG) for providing instructions as to basic operations such as writing, erasing, reading, etc., a boosted voltage attainment detecting circuit for detecting whether a voltage boosted by a booster circuit has reached a desired level, a circuit which counts the time required to apply each of write and erase voltages, and a circuit which detects the completion of the writing or erasing. Respective operations are automatically advanced by simple setting of the operation instructions to the control register. After the completion of the operations, an end flag (FLAG) provided within the control register is set to notify the completion of the writing or erasing.
    Type: Application
    Filed: October 5, 2001
    Publication date: April 25, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Hiroyuki Tanikawa, Toshihiro Tanaka, Yutaka Shinagawa, Yoshiki Kawajiri, Masamichi Fujito
  • Publication number: 20020041527
    Abstract: Disclosed is a nonvolatile memory with a shortened total write time, capable of stably writing data by making a write current constant while reducing fluctuations in a voltage generated by a booster circuit. In a nonvolatile memory such as a flash memory, data is determined at the time of writing operation. While skipping a bit corresponding to write data having the logic “1” (or logic “0”), writing operation to bits corresponding to write data having the logic “0” (or logic “1) is successively performed.
    Type: Application
    Filed: September 28, 2001
    Publication date: April 11, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Toshihiro Tanaka, Yutaka Shinagawa, Kazufumi Suzukawa, Masamichi Fujito, Takashi Yamaki, Kiichi Makuta, Masashi Wada, Yoshiki Kawajiri
  • Publication number: 20020027233
    Abstract: A semiconductor device whose characteristics are highly reliably regulated for circuits whose desired characteristics need to be realized without being affect by unevenness in device characteristics is to be provided. A replica MOS transistor for amperage measurement connected to an external measuring terminal is provided. A delay circuit and other circuits whose desired characteristics are to be realized have a constant current source MOS transistor formed in the same process as the replica MOS transistor, and a trimming voltage vtri is commonly applied to the respective gates of the constant current source MOS transistor and the replica MOS transistor. Trimming data determined on the basis of an amperage measured from the external measuring terminal are stored into a memory means such as an electrically rewritable non-volatile memory or the like. The trimming data determine the trimming voltage vtri.
    Type: Application
    Filed: August 28, 2001
    Publication date: March 7, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Takashi Yamaki, Kan Takeuchi, Mitsuru Hirakii, Toshihiro Tanaka, Yutaka Shinagawa, Masamichi Fujito
  • Publication number: 20020008992
    Abstract: The present invention proposes a non-volatile semiconductor storage, comprising a plurality of main bit lines, a plurality of sub bit lines connected to the main bit lines, and a plurality of memory cell arrays, each including a plurality of non-volatile semiconductor memory cells disposed like an array. Each of those memory cells has a source terminal, a drain terminal, and a control gate, and each source-drain path is connected to a sub bit line. Between a main bit line and a sub bit line connected to the main bit line is disposed the source-drain path of a first transistor, and the source-drain path of a second transistor is connected to the sub bit line.
    Type: Application
    Filed: September 14, 2001
    Publication date: January 24, 2002
    Inventors: Toshihiro Tanaka, Yutaka Shinagawa, Kazuyoshi Shiba, Kazufumi Suzukawa, Masamichi Fujito, Takayuki Oshima, Sonoko Abe, Kiyoshi Matsubara
  • Patent number: 6307780
    Abstract: The present invention proposes a non-volatile semiconductor storage, comprising a plurality of main bit lines, a plurality of sub bit lines connected to the main bit lines, and a plurality of memory cell arrays, each including a plurality of non-volatile semiconductor memory cells disposed like an array. Each of those memory cells has a source terminal, a drain terminal, and a control gate, and each source-drain path is connected to a sub bit line. Between a main bit line and a sub bit line connected to the main bit line is disposed the source-drain path of a first transistor, and the source-drain path of a second transistor is connected to the sub bit line.
    Type: Grant
    Filed: July 27, 2000
    Date of Patent: October 23, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Toshihiro Tanaka, Yutaka Shinagawa, Kazuyoshi Shiba, Kazufumi Suzukawa, Masamichi Fujito, Takayuki Oshima, Sonoko Abe, Kiyoshi Matsubara
  • Patent number: 6122196
    Abstract: The present invention proposes a non-volatile semiconductor storage, comprising a plurality of main bit lines, a plurality of sub bit lines connected to the main bit lines, and a plurality of memory cell arrays, each including a plurality of non-volatile semiconductor memory cells disposed like an array. Each of those memory cells has a source terminal, a drain terminal, and a control gate, and each source-drain path is connected to a sub bit line. Between a main bit line and a sub bit line connected to the main bit line is disposed the source-drain path of a first transistor, and the source-drain path of a second transistor is connected to the sub bit line.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: September 19, 2000
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Toshihiro Tanaka, Yutaka Shinagawa, Kazuyoshi Shiba, Kazufumi Suzukawa, Masamichi Fujito, Takayuki Oshima, Sonoko Abe, Kiyoshi Matsubara