Patents by Inventor Kazumasa Yanagisawa

Kazumasa Yanagisawa 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: 6381671
    Abstract: To enhance the speed of first access (read access different in word line from the previous access) to a multi-bank memory, multi-bank memory macro structures are used. Data are held in a sense amplifier for every memory bank. When access is hit to the held data, data latched by the sense amplifier are output to thereby enhance the speed of first access to the memory macro structures. Namely, each memory bank is made to function as a sense amplifier cache. To enhance the hit ratio of such a sense amplifier cache more greatly, an access controller self-prefetches the next address (an address to which a predetermined offset has been added) after access to a memory macro structure so that data in the self-prefetched address are preread by a sense amplifier in another memory bank.
    Type: Grant
    Filed: June 29, 1999
    Date of Patent: April 30, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Kazushige Ayukawa, Seiji Miura, Jun Satoh, Takao Watanabe, Kazumasa Yanagisawa, Yusuke Kanno, Hiroyuki Mizuno
  • Publication number: 20020012272
    Abstract: A semiconductor integrated circuit includes non-volatile memory elements (PM1, PM2), each of which has a first source electrode, a first drain electrode, a floating gate electrode and a control gate electrode and is capable of having different threshold voltages, and read transistor elements (DM1, DM2), each of which has a second source electrode and a second drain electrode and is capable of having different mutual conductances according to the threshold voltage of the non-volatile memory element. The read transistor element has a switching state according to the electron injection state or the electron emission state, in other words, the writing state or the erasing state of the floating gate electrode. In a read operation, it is not necessary to flow a channel current according to the threshold voltage of the non-volatile memory element.
    Type: Application
    Filed: March 9, 2001
    Publication date: January 31, 2002
    Inventors: Shoji Shukuri, Kazumasa Yanagisawa
  • Publication number: 20020009834
    Abstract: A semiconductor IC device is designed using a memory core with a plurality of I/O lines, a transfer circuit module and a logic library which are produced beforehand and stored in a data base. The memory core and a logic circuit are arranged so that their I/O lines extend in the same direction. A transfer circuit including plural stages of switch groups is arranged between the I/O lines of the memory core and the I/O lines of the logic circuit. Switches forming each stage of switch group are formed between the I/O lines of the memory core and the I/O lines of the logic circuit. When one stage of or a small number of stages of switch groups are turned on, the I/O lines of the memory core and the I/O lines of the logic circuit are turned on, thereby forming a desired transfer pattern. The memory core is constructed by the combination of functional modules such as an amplifier module, a bank module and a power supply module.
    Type: Application
    Filed: September 28, 2001
    Publication date: January 24, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Takao Watanabe, Kazushige Ayukawa, Ryo Fujita, Kazumasa Yanagisawa
  • Patent number: 6335898
    Abstract: A semiconductor IC device is designed using a memory core with a plurality of I/O lines, a transfer circuit module and a logic library which are produced beforehand and stored in a data base. The memory core and a logic circuit are arranged so that their I/O lines extend in the same direction. A transfer circuit including plural stages of switch groups is arranged between the I/O lines of the memory core and the I/O lines of the logic circuit. Switches forming each stage of switch group are formed between the I/O lines of the memory core and the I/O lines of the logic circuit. When one stage of or a small number of stages of switch groups are turned on, the I/O lines of the memory core and the I/O lines of the logic circuit are turned on, thereby forming a desired transfer pattern. The memory core is constructed by the combination of functional modules such as an amplifier module, a bank module and a power supply module.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: January 1, 2002
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corporation
    Inventors: Takao Watanabe, Kazushige Ayukawa, Ryo Fujita, Kazumasa Yanagisawa, Hitoshi Tanaka
  • Patent number: 6314044
    Abstract: A RAM mounted so as to mix with logic circuits has a plurality of memory mats and one control circuit provided for the plurality of memory mats. Arithmetic circuits for respectively performing +1 or −1 arithmetic operation are respectively provided so as to correspond to the respective memory mats and are electrically connected in cascade form. An input terminal of the initial-stage arithmetic circuit is supplied with address-setting fixed address signals. Input signals supplied to the next and subsequent arithmetic circuits or signals outputted therefrom are defined as own-assigned address signals (those assigned to the corresponding memory mats). A comparator provided in association with each arithmetic circuit referred to above makes comparisons for coincidence between the address signals and address signals input upon memory access. The corresponding memory mat is selected based on the resultant coincidence signal.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: November 6, 2001
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Toshio Sasaki, Yuji Tanaka, Kazumasa Yanagisawa, Hitoshi Tanaka, Jun Sato, Takashi Miyamoto, Mariko Ohtsuka, Satoru Nakanishi, Kazushige Ayukawa, Takao Watanabe
  • Publication number: 20010028581
    Abstract: A dynamic RAM includes sense amplifiers each formed of a latch circuit consisting of MOSFETs of a first and second conductivity types with the application of a first and second voltages to the sources thereof, respectively, and having a pair of input/output nodes corresponding to a first bit line pair which is connected with a number of dynamic memory cells, and further includes pairs of switching MOSFETs of the first conductivity type which connect selectively an input/output node pair of the latch circuits to a pair of second bit lines provided commonly to a plurality of the first bit line pair in response to the reception of the select signal. The switching MOSFETs have their threshold voltage set smaller in terms of absolute value than the threshold voltage of the MOSFETs of the first conductivity type of the latch circuits, and the select signal has its level of turning off the switching MOSFETs set greater in terms of absolute value than the first voltage with respect to the second voltage.
    Type: Application
    Filed: March 30, 2001
    Publication date: October 11, 2001
    Applicant: Hitachi, Ltd.
    Inventors: Kazumasa Yanagisawa, Toshio Sasaki, Satoru Nakanishi, Yoshihiko Yasu
  • Patent number: 6301184
    Abstract: A DRAM module is applied to the system LSI which is provided with a standby mode for suppressing the whole operation thereof and an operation standby mode which permits at least the DRAM module to operate but suppresses the operation of other circuits. The above-mentioned modes as well as a substrate bias control technology are applied to the CMOS system LSI that operates on a low voltage. The system LSI is controlled to hold or not to hold data, enabling a memory of a large capacity to be mounted and consuming a sufficiently decreased amount of electric power.
    Type: Grant
    Filed: January 11, 2000
    Date of Patent: October 9, 2001
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Toshio Sasaki, Yoshihiko Yasu, Kazumasa Yanagisawa, Yuji Tanaka, Toshiaki Takahira, Yasuto Igarashi, Mariko Ohtsuka, Yasunobu Aoki
  • Publication number: 20010019499
    Abstract: To reduce cost of defect redundancy and trimming in a semiconductor integrated circuit having multiple layer wirings and copper wirings, address for salvaging defect of a memory cell array in a semiconductor is stored by using a nonvolatile memory element constituting a floating electrode by a first layer of polysilicon, or the nonvolatile memory element is programmed in testing the semiconductor integrated circuit, thereby, a special process is not needed in forming the nonvolatile memory element, that is, the nonvolatile memory element can be formed in a process of forming CMOS device and apparatus of laser beam for programming is not needed since the programming is carried out in testing, time necessary for programming can be shortened and therefore, testing cost can be reduced.
    Type: Application
    Filed: February 12, 2001
    Publication date: September 6, 2001
    Inventors: Koichiro Ishibashi, Shoji Shukuri, Kazumasa Yanagisawa, Junichi Nishimoto, Masanao Yamaoka, Masakazu Aoki
  • Publication number: 20010014051
    Abstract: A semiconductor IC device is designed using a memory core with a plurality of I/O lines, a transfer circuit module and a logic library which are produced beforehand and stored in a data base. The memory core and a logic circuit are arranged so that their I/O lines extend in the same direction. A transfer circuit including plural stages of switch groups is arranged between the I/O lines of the memory core and the I/O lines of the logic circuit. Switches forming each stage of switch group are formed between the I/O lines of the memory core and the I/O lines of the logic circuit. When one stage of or a small number of stages of switch groups are turned on, the I/O lines of the memory core and the I/O lines of the logic circuit are turned on, thereby forming a desired transfer pattern. The memory core is constructed by the combination of functional modules such as an amplifier module, a bank module and a power supply module.
    Type: Application
    Filed: March 16, 2001
    Publication date: August 16, 2001
    Applicant: Hitachi, Ltd.
    Inventors: Takao Watanabe, Kazushiqe Ayukawa, Ryo Fujita, Kazumasa Yanagisawa, Hitoshi Tanaka
  • Publication number: 20010009551
    Abstract: Provided is a high-throughput large-capacity ATM switch in which variation in memory access time and data output delay time generated in the case where a DRAM is used as a cell buffer of the ATM switch is absorbed. To realize this, the ATM switch comprises a first memory using a DRAM for storing cells, a second memory using an SRAM for switching and temporarily storing the cells before transferring the cells to the first memory, and a controller for generating write/read address and timing signals for the first and second memories. The controller generates read address and timing signals for the second memory and write address and timing signals for the first memory taking variation in access time or delay time based on access address of the first memory into account, so that the cells are output on destination output lines after the cells are switched and stored in the second memory and then stored in the first memory.
    Type: Application
    Filed: March 5, 2001
    Publication date: July 26, 2001
    Inventors: Norihiko Moriwaki, Kenichi Sakamoto, Akihiko Takase, Akio Makimoto, Kazumasa Yanagisawa
  • Patent number: 6249524
    Abstract: Provided is a high-throughput large-capacity ATM switch in which variation in memory access time and data output delay time generated in the case where a DRAM is used as a cell buffer of the ATM switch is absorbed. To realize this, the ATM switch comprises a first memory using a DRAM for storing cells, a second memory using an SRAM for switching and temporarily storing the cells before transferring the cells to the first memory, and a controller for generating write/read address and timing signals for the first and second memories. The controller generates read address and timing signals for the second memory and write address and timing signals for the first memory taking variation in access time or delay time based on access address of the first memory into account, so that the cells are output on destination output lines after the cells are switched and stored in the second memory and then stored in the first memory.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: June 19, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Norihiko Moriwaki, Kenichi Sakamoto, Akihiko Takase, Akio Makimoto, Kazumasa Yanagisawa
  • Patent number: 6246629
    Abstract: A semiconductor IC device is designed using a memory core with a plurality of I/O lines, a transfer circuit module and a logic library which are produced beforehand and stored in a data base. The memory core and a logic circuit are arranged so that their I/O lines extend in the same direction. A transfer circuit including plural stages of switch groups is arranged between the I/O lines of the memory core and the I/O lines of the logic circuit. Switches forming each stage of switch group are formed between the I/O lines of the memory core and the I/O lines of the logic circuit. When one stage of or a small number of stages of switch groups are turned on, the I/O lines of the memory core and the I/O lines of the logic circuit are turned on, thereby forming a desired transfer pattern. The memory core is constructed by the combination of functional modules such as an amplifier module, a bank module and a power supply module.
    Type: Grant
    Filed: April 18, 2000
    Date of Patent: June 12, 2001
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corp.
    Inventors: Takao Watanabe, Kazushige Ayukawa, Ryo Fujita, Kazumasa Yanagisawa, Hitoshi Tanaka
  • Patent number: 6115319
    Abstract: A bootstrap circuit is provided for a word line selector for setting word lines connected with dynamic memory cells at a select level corresponding to a first voltage and a nonselect level corresponding to a second voltage. The bootstrap circuit generates a bootstrap voltage which is given a difference substantially equal to the threshold voltage of address select MOSFETs with respect to the high level of bit lines connected with the memory cells, and feeds the bootstrap voltage to the selected word lines. The bootstrap circuit is activated in synchronism with a clock signal at a timing corresponding to an action mode designated by a command in an SDRAM before a precharge action, thereby changing the select level of the word lines from the first voltage to the bootstrap voltage.
    Type: Grant
    Filed: February 13, 1998
    Date of Patent: September 5, 2000
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corp.
    Inventors: Yoshitaka Kinoshita, Kenji Nishimoto, Kazumasa Yanagisawa, Hitoshi Tanaka
  • Patent number: 6108264
    Abstract: An ordinary read/write operation (normal operation) and a refresh operation are separated from one another and the number of read amplification circuits or, in other words, the number of sense amplifiers operating during the normal operation is made smaller than that during the refresh operation. Accordingly, a bit line charge/discharge current during the normal operation can be reduced.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: August 22, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Takahashi, Takashi Shinoda, Masamichi Ishihara, Tetsu Udagawa, Kazumasa Yanagisawa
  • Patent number: 6097663
    Abstract: A semiconductor IC device is designed using a memory core with a plurality of I/O lines, a transfer circuit module and a logic library which are produced beforehand and stored in a data base. The memory core and a logic circuit are arranged so that their I/O lines extend in the same direction. A transfer circuit including plural stages of switch groups is arranged between the I/O lines of the memory core and the I/O lines of the logic circuit. Switches forming each stage of switch group are formed between the I/O lines of the memory core and the I/O lines of the logic circuit. When one stage of or a small number of stages of switch groups are turned on, the I/O lines of the memory core and the I/O lines of the logic circuit are turned on, thereby forming a desired transfer pattern. The memory core is constructed by the combination of functional modules such as an amplifier module, a bank module and a power supply module.
    Type: Grant
    Filed: October 6, 1999
    Date of Patent: August 1, 2000
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corporation
    Inventors: Takao Watanabe, Kazushige Ayukawa, Ryo Fujita, Kazumasa Yanagisawa, Hitoshi Tanaka
  • Patent number: 6091660
    Abstract: A RAM mounted so as to mix with logic circuits has a plurality of memory mats and one control circuit provided for the plurality of memory mats. Arithmetic circuits for respectively performing +1 or -1 arithmetic operations are respectively provided so as to correspond to the respective memory mats and are electrically connected in cascade form. An input terminal of the initial-stage arithmetic circuit is supplied with address-setting fixed address signals. Input signals supplied to the next and subsequent arithmetic circuits or signals outputted therefrom are defined as own-assigned address signals (those assigned to the corresponding memory mats). A comparator provided in association with each arithmetic circuit referred to above makes comparisons for coincidence between the address signals and address signals input upon memory access. The corresponding memory mat is selected based on the resultant coincidence signal.
    Type: Grant
    Filed: August 18, 1999
    Date of Patent: July 18, 2000
    Assignees: Hitachi, Ltd., Hitachi USLI Systems Co., Ltd.
    Inventors: Toshio Sasaki, Yuji Tanaka, Kazumasa Yanagisawa, Hitoshi Tanaka, Jun Sato, Takashi Miyamoto, Mariko Ohtsuka, Satoru Nakanishi, Kazushige Ayukawa, Takao Watanabe
  • Patent number: 6069834
    Abstract: A semiconductor IC device is designed using a memory core with a plurality of I/O lines, a transfer circuit module and a logic library which are produced beforehand and stored in a data base. The memory core and a logic circuit are arranged so that their I/O lines extend in the same direction. A transfer circuit including plural stages of switch groups is arranged between the I/O lines of the memory core and the I/O lines of the logic circuit. Switches forming each stage of switch group are formed between the I/O lines of the memory core and the I/O lines of the logic circuit. When one stage of or a small number of stages of switch groups are turned on, the I/O lines of the memory core and the I/O lines of the logic circuit are turned on, thereby forming a desired transfer pattern. The memory core is constructed by the combination of functional modules such as an amplifier module, a bank module and a power supply module.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: May 30, 2000
    Assignees: Hitachi, Ltd., Hitachi Ulsi Engineering Corporation
    Inventors: Takao Watanabe, Kazushige Ayukawa, Ryo Fujita, Kazumasa Yanagisawa, Hitoshi Tanaka
  • Patent number: 5995439
    Abstract: A semiconductor IC device is designed using a memory core with a plurality of I/O lines, a transfer circuit module and a logic library which are produced beforehand and stored in a data base. The memory core and a logic circuit are arranged so that their I/O lines extend in the same direction. A transfer circuit including plural stages of switch groups is arranged between the I/O lines of the memory core and the I/O lines of the logic circuit. Switches forming each stage of switch group are formed between the I/O lines of the memory core and the I/O lines of the logic circuit. When one stage of or a small number of stages of switch groups are turned on, the I/O lines of the memory core and the I/O lines of the logic circuit are turned on, thereby forming a desired transfer pattern. The memory core is constructed by the combination of functional modules such as an amplifier module, a bank module and a power supply module.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: November 30, 1999
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corporation
    Inventors: Takao Watanabe, Kazushige Ayukawa, Ryo Fujita, Kazumasa Yanagisawa, Hitoshi Tanaka
  • Patent number: 5978305
    Abstract: A RAM mounted so as to mix with logic circuits has a plurality of memory mats and one control circuit provided for the plurality of memory mats. Arithmetic circuits for respectively performing +1 or -1 arithmetic operations are respectively provided so as to correspond to the respective memory mats and are electrically connected in cascade form. An input terminal of the initial-stage arithmetic circuit is supplied with address-setting fixed address signals. Input signals supplied to the next and subsequent arithmetic circuits or signals outputted therefrom are defined as own-assigned address signals (those assigned to the corresponding memory mats). A comparator provided in association with each arithmetic circuit referred to above makes comparisons for coincidence between the address signals and address signals input upon memory access. The corresponding memory mat is selected based on the resultant coincidence signal.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: November 2, 1999
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Toshio Sasaki, Yuji Tanaka, Kazumasa Yanagisawa, Hitoshi Tanaka, Jun Sato, Takashi Miyamoto, Mariko Ohtsuka, Satoru Nakanishi, Kazushige Ayukawa, Takao Watanabe
  • Patent number: 5862095
    Abstract: An ordinary read/write operation (normal operation) and a refresh operation are separated from one another and the number of read amplification circuits or in other words, the number of sense amplifiers operating during the normal operation is made smaller than that during the refresh operation. Accordingly, a bit line charge/discharge current during the normal operation can be reduced.
    Type: Grant
    Filed: October 31, 1997
    Date of Patent: January 19, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Takahashi, Takashi Shinoda, Masamichi Ishihara, Tetsu Udagawa, Kazumasa Yanagisawa