Patents by Inventor Masaki Tsukude

Masaki Tsukude 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: 10515672
    Abstract: A semiconductor memory device including a pair of first bit lines extended in a first direction, a pair of second bit lines extended in the first direction, a first word line extended in a second direction crossing the first direction, a second word line extended in the second direction, a memory cell surrounded by the first bit line, the second bit line, the first word line, and the second word line, and including a drive transistor, a first transfer transistor coupled with one of the pair of first bit lines, and having a gate coupled with the first word line, a second transfer transistor coupled with one of the pair of second bit lines, and having a gate coupled with the second word line, and a load transistor, a write drive circuit that transfers data to the memory cell.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: December 24, 2019
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Shinji Tanaka, Yuichiro Ishii, Masaki Tsukude, Yoshikazu Saito
  • Publication number: 20190122703
    Abstract: A semiconductor memory device including a pair of first bit lines extended in a first direction, a pair of second bit lines extended in the first direction, a first word line extended in a second direction crossing the first direction, a second word line extended in the second direction, a memory cell surrounded by the first bit line, the second bit line, the first word line, and the second word line, and including a drive transistor, a first transfer transistor coupled with one of the pair of first bit lines, and having a gate coupled with the first word line, a second transfer transistor coupled with one of the pair of second bit lines, and having a gate coupled with the second word line, and a load transistor, a write drive circuit that transfers data to the memory cell.
    Type: Application
    Filed: December 21, 2018
    Publication date: April 25, 2019
    Inventors: Shinji Tanaka, Yuichiro Ishii, Masaki Tsukude, Yoshikazu Saito
  • Patent number: 10170161
    Abstract: A test method for a semiconductor memory device having a plurality of memory cells arranged in a matrix form, the test method including writing first data into a plurality of memory cells, while a plurality of word lines disposed in the columns of the memory cells are deselected, driving the low-potential side bit line of a bit line pair in the selected column, which is among a plurality of bit line pairs disposed in the columns of the memory cells, to a negative voltage level in accordance with second data complementary to the first data, and reading the data written into the memory cells.
    Type: Grant
    Filed: October 12, 2017
    Date of Patent: January 1, 2019
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Shinji Tanaka, Yuichiro Ishii, Masaki Tsukude, Yoshikazu Saito
  • Publication number: 20180047457
    Abstract: A test method for a semiconductor memory device having a plurality of memory cells arranged in a matrix form, the test method including writing first data into a plurality of memory cells, while a plurality of word lines disposed in the columns of the memory cells are deselected, driving the low-potential side bit line of a bit line pair in the selected column, which is among a plurality of bit line pairs disposed in the columns of the memory cells, to a negative voltage level in accordance with second data complementary to the first data, and reading the data written into the memory cells.
    Type: Application
    Filed: October 12, 2017
    Publication date: February 15, 2018
    Inventors: Shinji TANAKA, Yuichiro ISHII, Masaki TSUKUDE, Yoshikazu SAITO
  • Patent number: 9805821
    Abstract: A semiconductor memory device includes a memory array including a plurality of memory cells arranged in a matrix form, a plurality of bit line pairs disposed in the columns of the memory cells, a plurality of word lines disposed in the rows of the memory cells, a write drive circuit adapted to transfer data to a bit line pair in a selected column in accordance with write data, and a control circuit that deselects the word lines during a test and drives a low-potential side bit line of the bit line pair in the selected column to a negative voltage level in accordance with the potentials of bit lines in the selected column.
    Type: Grant
    Filed: August 11, 2016
    Date of Patent: October 31, 2017
    Assignee: Renesas Electronics Corporation
    Inventors: Shinji Tanaka, Yuichiro Ishii, Masaki Tsukude, Yoshikazu Saito
  • Publication number: 20170092378
    Abstract: Provided is a semiconductor memory device that is capable of accurately detecting a retention failure of a memory cell. The semiconductor memory device includes a memory array including a plurality of memory cells arranged in a matrix form, a plurality of bit line pairs disposed in the columns of the memory cells, a plurality of word lines disposed in the rows of the memory cells, a write drive circuit adapted to transfer data to a bit line pair in a selected column in accordance with write data, and a control circuit that deselects the word lines during a test and drives a low-potential side bit line of the bit line pair in the selected column to a negative voltage level in accordance with the potentials of bit lines in the selected column.
    Type: Application
    Filed: August 11, 2016
    Publication date: March 30, 2017
    Inventors: Shinji TANAKA, Yuichiro ISHll, Masaki TSUKUDE, Yoshikazu SAITO
  • Patent number: 8061895
    Abstract: There is provided a semiconductor device which can maintain a high tuning accuracy while suppressing a cost increase and suppress an increase in the time required for tuning. There are included, in addition to variable resistors configuring a level shift circuit, an additional resistor coupled between the output node of a VBGR voltage of a BGR circuit and one of the variable resistors and an additional resistor coupled between the other of the variable resistors and a reference voltage. N-channel MOS transistors are coupled in parallel with the additional resistors, respectively.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: November 22, 2011
    Assignee: Renesas Electronics Corporation
    Inventor: Masaki Tsukude
  • Publication number: 20110199844
    Abstract: A semiconductor memory device for operating in synchronization with a clock is disclosed. The semiconductor includes a memory array having a plurality of memory cells arranged in rows and columns; and a control circuit performing a control, operation to effect row access processing on a selected row and to effect column access processing on column(s). The control being performed in synchronization with a first clock defined by a time of production of the read signal or the write signal according to an externally applied control signal.
    Type: Application
    Filed: April 7, 2011
    Publication date: August 18, 2011
    Applicant: Renesas Technology Corp.
    Inventors: Takeo Miki, Seiji Sawada, Masaki Tsukude
  • Patent number: 7983103
    Abstract: A trigger producing circuit provides a trigger signal. A delay circuit receives the trigger signal, and provides a delay signal produced by delaying the trigger signal. A clock counter receives clocks, counts the received clocks for a period from reception of the trigger signal to reception of the delay signal, and provides a result of the counting. A determining circuit stores a relationship between the number of clocks and a latency, and determines the latency corresponding to the result of counting provided from the clock counter. A latency register holds the determined latency. A WAIT control circuit externally provides a WAIT signal based on the latency held in the latency register.
    Type: Grant
    Filed: December 12, 2008
    Date of Patent: July 19, 2011
    Assignee: Renesas Electronics Corporation
    Inventor: Masaki Tsukude
  • Patent number: 7693004
    Abstract: This invention discloses a semiconductor memory device having a voltage supply circuit for generating a driver power supply voltage. The voltage supply circuit is provided with a first voltage supply circuit for precharging the driver power supply voltage to a power supply voltage level of a memory cell, and a second voltage supply circuit for supplying a voltage lower than the power supply voltage level of the memory cell as the driver power supply voltage.
    Type: Grant
    Filed: January 14, 2008
    Date of Patent: April 6, 2010
    Assignee: Renesas Technology Corp.
    Inventor: Masaki Tsukude
  • Publication number: 20090196326
    Abstract: There is provided a semiconductor device which can maintain a high tuning accuracy while suppressing a cost increase and suppress an increase in the time required for tuning. There are included, in addition to variable resistors configuring a level shift circuit, an additional resistor coupled between the output node of a VBGR voltage of a BGR circuit and one of the variable resistors and an additional resistor coupled between the other of the variable resistors and a reference voltage. N-channel MOS transistors are coupled in parallel with the additional resistors, respectively.
    Type: Application
    Filed: January 30, 2009
    Publication date: August 6, 2009
    Inventor: Masaki TSUKUDE
  • Publication number: 20090091997
    Abstract: A trigger producing circuit provides a trigger signal. A delay circuit receives the trigger signal, and provides a delay signal produced by delaying the trigger signal. A clock counter receives clocks, counts the received clocks for a period from reception of the trigger signal to reception of the delay signal, and provides a result of the counting. A determining circuit stores a relationship between the number of clocks and a latency, and determines the latency corresponding to the result of counting provided from the clock counter. A latency register holds the determined latency. A WAIT control circuit externally provides a WAIT signal based on the latency held in the latency register.
    Type: Application
    Filed: December 12, 2008
    Publication date: April 9, 2009
    Applicant: RENESAS TECHNOLOGY CORP.
    Inventors: Takeo Miki, Seiji Sawada, Masaki TSUKUDE
  • Patent number: 7447098
    Abstract: In a DRAM having a complete hidden refresh function, when data refresh is to be carried out in an active mode, a signal for selecting a way is set to an “H” level and then reset to an “L” level at each cycle while the corresponding upper address is designated. When data refresh is to be carried out in a standby mode, the signal for selecting the way is maintained at an “H” level and is not reset to an “L” level while the corresponding upper address is designated. This can reduce the standby current.
    Type: Grant
    Filed: October 24, 2007
    Date of Patent: November 4, 2008
    Assignee: Renesas Technology Corp.
    Inventor: Masaki Tsukude
  • Publication number: 20080258805
    Abstract: The composing circuit outputs a lower voltage out of voltages output from the constant voltage generation circuit and the dummy pump circuit as a voltage to the sensing circuit. The sensing circuit compares voltages to generate a pump activation signal for activating the pump circuit. Since when an external power supply voltage is a low voltage, the voltage applied to the sensing circuit will be an output voltage of the dummy pump circuit having the same output characteristics as those of the pump circuit in place of the reference voltage, no pump activation signal is generated. As a result, when the external power supply voltage is a low voltage, power consumption can be suppressed without uselessly outputting a pump activation signal.
    Type: Application
    Filed: June 17, 2008
    Publication date: October 23, 2008
    Applicant: RENESAS TECHNOLOGY CORP.
    Inventor: Masaki Tsukude
  • Publication number: 20080205184
    Abstract: This invention discloses a semiconductor memory device having a voltage supply circuit for generating a driver power supply voltage. The voltage supply circuit is provided with a first voltage supply circuit for precharging the driver power supply voltage to a power supply voltage level of a memory cell, and a second voltage supply circuit for supplying a voltage lower than the power supply voltage level of the memory cell as the driver power supply voltage.
    Type: Application
    Filed: January 14, 2008
    Publication date: August 28, 2008
    Inventor: Masaki TSUKUDE
  • Patent number: 7397298
    Abstract: The composing circuit outputs a lower voltage out of voltages output from the constant voltage generation circuit and the dummy pump circuit as a voltage to the sensing circuit. The sensing circuit compares voltages to generate a pump activation signal for activating the pump circuit. Since when an external power supply voltage is a low voltage, the voltage applied to the sensing circuit will be an output voltage of the dummy pump circuit having the same output characteristics as those of the pump circuit in place of the reference voltage, no pump activation signal is generated. As a result, when the external power supply voltage is a low voltage, power consumption can be suppressed without uselessly outputting a pump activation signal.
    Type: Grant
    Filed: July 27, 2006
    Date of Patent: July 8, 2008
    Assignee: Renesas Technology Corp.
    Inventor: Masaki Tsukude
  • Publication number: 20080062776
    Abstract: In a DRAM having a complete hidden refresh function, when data refresh is to be carried out in an active mode, a signal for selecting a way is set to an “H” level and then reset to an “L” level at each cycle while the corresponding upper address is designated. When data refresh is to be carried out in a standby mode, the signal for selecting the way is maintained at an “H” level and is not reset to an “L” level while the corresponding upper address is designated. This can reduce the standby current.
    Type: Application
    Filed: October 24, 2007
    Publication date: March 13, 2008
    Applicant: RENESAS TECHNOLOGY CORPORATION
    Inventor: Masaki Tsukude
  • Patent number: 7301843
    Abstract: In a DRAM having a complete hidden refresh function, when data refresh is to be carried out in an active mode, a signal for selecting a way is set to an “H” level and then reset to an “L” level at each cycle while the corresponding upper address is designated. When data refresh is to be carried out in a standby mode, the signal for selecting the way is maintained at an “H” level and is not reset to an “L” level while the corresponding upper address is designated. This can reduce the standby current.
    Type: Grant
    Filed: March 15, 2006
    Date of Patent: November 27, 2007
    Assignee: Renesas Technology Corp.
    Inventor: Masaki Tsukude
  • Publication number: 20070024349
    Abstract: The composing circuit outputs a lower voltage out of voltages output from the constant voltage generation circuit and the dummy pump circuit as a voltage to the sensing circuit. The sensing circuit compares voltages to generate a pump activation signal for activating the pump circuit. Since when an external power supply voltage is a low voltage, the voltage applied to the sensing circuit will be an output voltage of the dummy pump circuit having the same output characteristics as those of the pump circuit in place of the reference voltage, no pump activation signal is generated. As a result, when the external power supply voltage is a low voltage, power consumption can be suppressed without uselessly outputting a pump activation signal.
    Type: Application
    Filed: July 27, 2006
    Publication date: February 1, 2007
    Inventor: Masaki Tsukude
  • Patent number: RE41245
    Abstract: Successive data read access with a final address specified is detected by a command mode detecting circuit to set a command mode entry status. In the command mode entry, a command of designating an internal state is made acceptable in accordance with a predetermined external signal. Consequently, a semiconductor memory device that enters a command mode, maintaining compatibility of pins and signal timings with a conventional status memory is provided.
    Type: Grant
    Filed: June 9, 2005
    Date of Patent: April 20, 2010
    Assignee: Renesas Technology Corporation
    Inventors: Ryu Makabe, Masaki Tsukude, Hirotoshi Sato, Shinichi Kobayashi