Patents by Inventor Osamu Nagashima

Osamu Nagashima 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).

  • Publication number: 20020093870
    Abstract: A semiconductor memory device has a column address decoder which includes first and second pre-decoders corresponding to high-order and low-order addresses, respectively, a shift register for using the output signal of the second pre-decoder as an initial value, and an output circuit for selecting either the output signal of the second pre-decoder or the output signal of the shift register in accordance with an action mode. The select signal is formed by the output signal of the first pre-decoder and the output signal through the output circuit. The shift register includes a first shift register for an even address and a second shift register for an odd address and forms two sets of continuous select signals of the bit lines, as composed of a sequential action and an interleave action, on the basis of the initial value by combining its up and down shifting actions.
    Type: Application
    Filed: March 15, 2002
    Publication date: July 18, 2002
    Inventors: Hiromasa Noda, Youji Idei, Osamu Nagashima, Tetsuo Ado
  • Patent number: 6411543
    Abstract: There is produced a first internal voltage having a difference relative to a power supply voltage, the difference being substantially equal to a threshold voltage of an address selection MOSFET of a dynamic memory cell. The first voltage is supplied to a sense amplifier as an operating voltage on a high-level side thereof. There is produced a second internal voltage having a predetermined difference relative to a circuit ground potential. The second voltage is supplied to the sense amplifier as an operating voltage on a low-level side thereof. A write signal having a high level corresponding to the first internal voltage and a low level corresponding to the second internal voltage is generated by a write amplifier to be transferred to a pair of complementary data lines connected to the dynamic memory cell. A high level, e.g., the power supply voltage representing a selection level and a low level, e.g.
    Type: Grant
    Filed: January 8, 2001
    Date of Patent: June 25, 2002
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corp.
    Inventors: Seiji Narui, Osamu Nagashima, Masatoshi Hasegawa, Hiroki Fujisawa, Shinichi Miyatake, Tsuyuki Suzuki, Yasunobu Aoki, Tsutom Takahashi, Kazuhiko Kajigaya
  • Patent number: 6407963
    Abstract: A semiconductor memory device of a DDR configuration improved in glitch immunity and the convenience of use is to be provided. It is a dynamic type RAM the operation of whose internal circuit is controlled in synchronism with a clock signal; an input circuit is provided in which a second clock signal inputted when in write operation is used to take in a plurality of write data serially inputted in response to that signal into a plurality of first latch circuits, and said first clock signal is used to take the write data taken into the first latch circuits into the second latch circuit to convey them to an input/output data bus; a logic circuit is provided to mask, in accordance with the logic of the first clock signal and the second clock signal, any noise arising at the end of the second clock signal, and a third clock signal is generated and supplied to the first latch circuits which output the write data to at least the input of the second latch circuits.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: June 18, 2002
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd
    Inventors: Takahiro Sonoda, Takeshi Sakata, Sadayuki Morita, Yoshinobu Nakagome, Haruko Tadokoro, Osamu Nagashima
  • Patent number: 6396761
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Grant
    Filed: June 7, 2001
    Date of Patent: May 28, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Publication number: 20020060944
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Application
    Filed: January 9, 2002
    Publication date: May 23, 2002
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Publication number: 20020057620
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Application
    Filed: January 9, 2002
    Publication date: May 16, 2002
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Publication number: 20020057601
    Abstract: Switch MOSFETs are interposed between a sense amplifier disposed in a dynamic RAM and complementary bit lines. After signal voltages are read out by selecting operations of word lines from a plurality of dynamic memory cells selected, to the plurality of pairs of complementary bit lines in accordance with individual storage informations, the switch control signal of the switch MOSFETs is changed from a select level to a predetermined intermediate level. This turns on the switch MOSFETs thereby setting sense nodes to one level in accordance with the amplifying operations of the sense amplifier. An amplification signal generated by the amplifying operation is transmitted through the column select circuit to input/output lines in response to the column select signal, and the switch control signal is returned to the select level in response to the selecting operation of the column select circuit.
    Type: Application
    Filed: January 15, 2002
    Publication date: May 16, 2002
    Inventors: Tatsuya Sakamoto, Osamu Nagashima, Riichiro Takemura
  • Publication number: 20020057619
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an, operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Application
    Filed: January 9, 2002
    Publication date: May 16, 2002
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Patent number: 6385100
    Abstract: A semiconductor memory device has a column address decoder which includes first and second pre-decoders corresponding to high-order and low-order addresses, respectively, a shift register for using the output signal of the second pre-decoder as an initial value, and an output circuit for selecting either the output signal of the second pre-decoder or the output signal of the shift register in accordance with an action mode. The select signal is formed by the output signal of the first pre-decoder and the output signal through the output circuit. The shift register includes a first shift register for an even address and a second shift register for an odd address and forms two sets of continuous select signals of the bit lines, as composed of a sequential action and an interleave action, on the basis of the initial value by combining its up and down shifting actions.
    Type: Grant
    Filed: February 22, 2001
    Date of Patent: May 7, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Noda, Youji Idei, Osamu Nagashima, Tetsuo Ado
  • Publication number: 20020030509
    Abstract: Differential amplifier circuits that receive input signals fed through external terminals are served with a first operation voltage and a second operation voltage through a first switching MOSFET and a second switching MOSFET, said first and second switching MOSFETs are turned on by a bis voltage-generating circuit when said input signal is near a central voltage of said first and second operation voltages, control voltages are formed to turn either said first switching MOSFET or said second switching MOSFET on and to turn the other one off to produce a corresponding output signal when the input signal continuously assumes said first voltage or said second voltage for a predetermined period of time, thereby to supply an input signal of a first amplitude corresponding to said first operation voltage and said second operation voltage as well as an input signal of a second amplitude corresponding to a predetermined intermediate voltage between said first operation voltage and said second operation voltage.
    Type: Application
    Filed: November 15, 2001
    Publication date: March 14, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Takeshi Sakata, Hitoshi Tanaka, Osamu Nagashima, Masafumi Ohi, Sadayuki Morita
  • Publication number: 20020018396
    Abstract: An SDRAM has its operation mode selected to be the SDR mode in response to the first state of the external terminal (OPT), thereby releasing data, which has been read out of a memory mat, in response to a clock signal produced by a clock regenerating circuit having a function of comparing the phases of the input and output of the circuit, or selected to be the DDR mode in response to the second state of the external terminal (OPT), thereby releasing data, which has been read out of the memory mat, in response to a clock signal produced by a clock signal generation circuit in synchronism with an external clock signal.
    Type: Application
    Filed: September 28, 2001
    Publication date: February 14, 2002
    Inventors: Sadayuki Morita, Takeshi Sakata, Satoru Hanzawa, Takahiro Sonoda, Haruko Tadokoro, Hiroshi Ichikawa, Osamu Nagashima
  • Patent number: 6341088
    Abstract: Switch MOSFETs are interposed between a sense amplifier disposed in a dynamic RAM and complementary bit lines. After signal voltages are read out by selecting operations of word lines from a plurality of dynamic memory cells selected, to the plurality of pairs of complementary bit lines in accordance with individual storage informations, the switch control signal of the switch MOSFETs is changed from a select level to a predetermined intermediate level. This turns on the switch MOSFETs thereby setting sense nodes to one level in accordance with the amplifying operations of the sense amplifier. An amplification signal generated by the amplifying operation is transmitted through the column select circuit to input/output lines in response to the column select signal, and the switch control signal is returned to the select level in response to the selecting operation of the column select circuit.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: January 22, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuya Sakamoto, Osamu Nagashima, Riichiro Takemura
  • Patent number: 6339344
    Abstract: Differential amplifier circuits that receive input signals fed through external terminals are served with a first operation voltage and a second operation voltage through a first switching MOSFET and a second switching MOSFET, said first and second switching MOSFETs are turned on by a bias voltage-generating circuit when said input signal is near a central voltage of said first and second operation voltages, control voltages are formed to turn either said first switching MOSFET or said second switching MOSFET on and to turn the other one off to produce a corresponding output signal when the input signal continuously assumes said first voltage or said second voltage for a predetermined period of time, thereby to supply an input signal of a first amplitude corresponding to said first operation voltage and said second operation voltage as well as an input signal of a second amplitude corresponding to a predetermined intermediate voltage between said first operation voltage and said second operation voltage.
    Type: Grant
    Filed: February 2, 2000
    Date of Patent: January 15, 2002
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Takeshi Sakata, Hitoshi Tanaka, Osamu Nagashima, Masafumi Ohi, Sadayuki Morita
  • Patent number: 6335901
    Abstract: An SDRAM has its operation mode selected to be the SDR mode in response to the first state of the external terminal (OPT), thereby releasing data, which has been read out of a memory mat, in response to a clock signal produced by a clock regenerating circuit having a function of comparing the phases of the input and output of the circuit, or selected to be the DDR mode in response to the second state of the external terminal (OPT), thereby releasing data, which has been read out of the memory mat, in response to a clock signal produced by a clock signal generation circuit in synchronism with an external clock signal.
    Type: Grant
    Filed: March 20, 2000
    Date of Patent: January 1, 2002
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Sadayuki Morita, Takeshi Sakata, Satoru Hanzawa, Takahiro Sonoda, Haruko Tadokoro, Hiroshi Ichikawa, Osamu Nagashima
  • Publication number: 20010026478
    Abstract: A semiconductor memory device comprising: a memory array including a plurality of word lines and a plurality of bit lines; and a column address decoder for selecting a predetermined bit line from the plurality of bit lines. The column address decoder includes: first and second pre-decoders corresponding to high-order and low-order addresses, respectively; a shift register for using the output signal of the second pre-decoder as an initial value; and an output circuit for selecting either the output signal of the second pre-decoder or the output signal of the shift register in accordance with an action mode. The select signal is formed by the output signal of the first pre-decoder and the output signal through the output circuit.
    Type: Application
    Filed: February 22, 2001
    Publication date: October 4, 2001
    Inventors: Hiromasa Noda, Youji Idei, Osamu Nagashima, Tetsuo Ado
  • Publication number: 20010026495
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Application
    Filed: June 7, 2001
    Publication date: October 4, 2001
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Patent number: 6275440
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon reaching its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Grant
    Filed: December 5, 2000
    Date of Patent: August 14, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Patent number: 6240035
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon reaching its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Grant
    Filed: April 30, 1999
    Date of Patent: May 29, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Publication number: 20010001598
    Abstract: There is produced a first internal voltage having a difference relative to a power supply voltage, the difference being substantially equal to a threshold voltage of an address selection MOSFET of a dynamic memory cell. The first voltage is supplied to a sense amplifier as an operating voltage on a high-level side thereof. There is produced a second internal voltage having a predetermined difference relative to a circuit ground potential. The second voltage is supplied to the sense amplifier as an operating voltage on a low-level side thereof. A write signal having a high level corresponding to the first internal voltage and a low level corresponding to the second internal voltage is generated by a write amplifier to be transferred to a pair of complementary data lines connected to the dynamic memory cell. A high level, e.g., the power supply voltage representing a selection level and a low level, e.g.
    Type: Application
    Filed: January 8, 2001
    Publication date: May 24, 2001
    Inventors: Seiji Narui, Osamu Nagashima, Masatoshi Hasegawa, Hiroki Fujisawa, Shinichi Miyatake, Tsuyuki Suzuki, Yasunobu Aoki, Tsutom Takahashi, Kazuhiko Kajigaya
  • Publication number: 20010000991
    Abstract: Switch MOSFETs are interposed between a sense amplifier disposed in a dynamic RAM and complementary bit lines: after signal voltages were read out by the selecting operations of the word lines from a plurality of dynamic memory cells selected, to the plurality of pairs of complementary bit lines in accordance with their individual storage informations, the switch control signal of the switch MOSFETs is changed from a select level to a predetermined intermediate level. The switch MOSFETs, as fed with the intermediate potential at their gates, are turned ON as a result that sense nodes are set to one level in accordance with the amplifying operations of the sense amplifier. An amplification signal generated by the amplifying operation is transmitted through the column select circuit to input/output lines in response to the column select signal, and the switch control signal is returned from the intermediate potential level to the select level in response to the selecting operation of the column select circuit.
    Type: Application
    Filed: December 29, 2000
    Publication date: May 10, 2001
    Inventors: Tatsuya Sakamoto, Osamu Nagashima, Riichiro Takemura