Patents by Inventor Koji Nii

Koji Nii 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: 9502112
    Abstract: A semiconductor memory device capable of a high-accuracy data search is provided. Each of the memory cells can hold two bits of information and includes a first cell and a second cell. The semiconductor memory device also includes a match line and a search line pair to transfer search data. The semiconductor memory device further includes a logic operation cell to drive the match line based on comparison results between information held in the first and the second cell and search data transferred by the search line pair and a search line driver to drive the search line pair. In a state with the search line pair precharged to a third voltage between a first voltage and a second voltage, the search line driver drives, according to the search data, one and the other search line included in the search line pair to the first and the second voltage, respectively.
    Type: Grant
    Filed: January 24, 2016
    Date of Patent: November 22, 2016
    Assignee: Renesas Electronics Corporation
    Inventor: Koji Nii
  • Patent number: 9496028
    Abstract: Cell power supply lines are arranged for memory cell columns, and adjust impedances or voltage levels of the cell power supply lines according to the voltage levels of bit lines in the corresponding columns, respectively. In the data write operation, the cell power supply line is forced into a floating state according to the bit line potential on a selected column and has the voltage level changed, and a latching capability of a selected memory cell is reduced to write data fast. Even with a low power supply voltage, a static semiconductor memory device that can stably perform write and read of data is implemented.
    Type: Grant
    Filed: November 16, 2015
    Date of Patent: November 15, 2016
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Koji Nii, Shigeki Obayashi, Hiroshi Makino, Koichiro Ishibashi, Hirofumi Shinohara
  • Patent number: 9449715
    Abstract: A semiconductor device having a capability of generating chip identification information includes: an SRAM macro having a plurality of memory cells arranged in rows and columns; a test address storage unit configured to store a test address; a self-diagnostic circuit configured to output the test address based on a result of confirmation of operation of the memory cell selected by the test address; and an identification information generation circuit configured to generate chip identification information based on the test address which is output by the self-diagnostic circuit.
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: September 20, 2016
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Hidehiro Fujiwara, Makoto Yabuuchi, Koji Nii, Yoshikazu Saito
  • Publication number: 20160247569
    Abstract: A semiconductor memory device capable of a high-accuracy data search is provided. Each of the memory cells can hold two bits of information and includes a first cell and a second cell. The semiconductor memory device also includes a match line and a search line pair to transfer search data. The semiconductor memory device further includes a logic operation cell to drive the match line based on comparison results between information held in the first and the second cell and search data transferred by the search line pair and a search line driver to drive the search line pair. In a state with the search line pair precharged to a third voltage between a first voltage and a second voltage, the search line driver drives, according to the search data, one and the other search line included in the search line pair to the first and the second voltage, respectively.
    Type: Application
    Filed: January 24, 2016
    Publication date: August 25, 2016
    Inventor: Koji NII
  • Publication number: 20160181255
    Abstract: In an image information chip or the like, a multi-port SRAM is embedded with a logic circuit. When the 3 port is used, the 1 port may serve as a differential write and readout port, and the 2 port may serve as a single ended readout dedicated port. While the occupied area of an embedded SRAM can be reduced, the number of write and readout ports is limited to only one, and readout characteristics as fast as differential readout cannot be expected in single ended readout. A new arrangement is therefore provided in which three differential write and readout ports are included in a memory cell structure of the embedded SRAM, an N-well region, for example, is arranged at the center of a cell, and a P-well region is arranged on both sides thereof.
    Type: Application
    Filed: August 6, 2013
    Publication date: June 23, 2016
    Inventor: Koji NII
  • Publication number: 20160172023
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Application
    Filed: February 24, 2016
    Publication date: June 16, 2016
    Applicant: Renesas Electronics Corporation
    Inventors: Koji NII, Shigeki OHBAYASHI, Yasumasa TSUKAMOTO, Makoto YABUUCHI
  • Publication number: 20160109915
    Abstract: A semiconductor device includes an identification information generation circuit having a power supply control circuit whose output voltage is controlled by a control signal, and a memory array having a first cell power line and a second cell power line. The power supply control circuit outputs a first supply voltage and a second supply voltage to a first cell power line and a second power line, respectively, when the control signal is in a first state, and outputs an intermediate voltage to the first cell power line and the second cell power line when the control signal is in a second state.
    Type: Application
    Filed: December 21, 2015
    Publication date: April 21, 2016
    Applicant: Renesas Electronics Corporation
    Inventors: Masanori ISODA, Hidehiro FUJIWARA, Koji NII
  • Patent number: 9299418
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: March 29, 2016
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Publication number: 20160078925
    Abstract: Cell power supply lines are arranged for memory cell columns, and adjust impedances or voltage levels of the cell power supply lines according to the voltage levels of bit lines in the corresponding columns, respectively. In the data write operation, the cell power supply line is forced into a floating state according to the bit line potential on a selected column and has the voltage level changed, and a latching capability of a selected memory cell is reduced to write data fast. Even with a low power supply voltage, a static semiconductor memory device that can stably perform write and read of data is implemented.
    Type: Application
    Filed: November 16, 2015
    Publication date: March 17, 2016
    Inventors: Koji NII, Shigeki OBAYASHI, Hiroshi MAKINO, Koichiro ISHIBASHI, Hirofumi SHINOHARA
  • Patent number: 9256261
    Abstract: A semiconductor device includes an identification information generation circuit having a power supply control circuit whose output voltage is controlled by a control signal, and a memory array having a first cell power line and a second cell power line. The power supply control circuit outputs a first supply voltage and a second supply voltage to a first cell power line and a second power line, respectively, when the control signal is in a first state, and outputs an intermediate voltage to the first cell power line and the second cell power line when the control signal is in a second state.
    Type: Grant
    Filed: May 28, 2013
    Date of Patent: February 9, 2016
    Assignee: Renesas Electronics Corporation
    Inventors: Masanori Isoda, Hidehiro Fujiwara, Koji Nii
  • Publication number: 20150380076
    Abstract: The invention provides a semiconductor integrated circuit device provided with an SRAM that satisfies the requirements for both the SNM and the write margin with a low supply voltage. The semiconductor integrated circuit device include: multiple static memory cells provided in correspondence with multiple word lines and multiple complimentary bit lines; multiple memory cell power supply lines that each supply an operational voltage to each of the multiple memory cells connected to the multiple complimentary bit lines each; multiple power supply circuits comprised of resistive units that each supply a power supply voltage to the memory cell power supply lines each; and a pre-charge circuit that supplies a pre-charge voltage corresponding to the power supply voltage to the complimentary bit lines, wherein the memory cell power supply lines are made to have coupling capacitances to thereby transmit a write signal on corresponding complimentary bit lines.
    Type: Application
    Filed: August 25, 2015
    Publication date: December 31, 2015
    Inventors: Noriaki MAEDA, Yoshihiro SHINOZAKI, Masanao YAMAOKA, Yasuhisa SHIMAZAKI, Masanori ISODA, Koji NII
  • Patent number: 9218873
    Abstract: Cell power supply lines are arranged for memory cell columns, and adjust impedances or voltage levels of the cell power supply lines according to the voltage levels of bit lines in the corresponding columns, respectively. In the data write operation, the cell power supply line is forced into a floating state according to the bit line potential on a selected column and has the voltage level changed, and a latching capability of a selected memory cell is reduced to write data fast. Even with a low power supply voltage, a static semiconductor memory device that can stably perform write and read of data is implemented.
    Type: Grant
    Filed: January 9, 2014
    Date of Patent: December 22, 2015
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Koji Nii, Shigeki Obayashi, Hiroshi Makino, Koichiro Ishibashi, Hirofumi Shinohara
  • Patent number: 9214222
    Abstract: A semiconductor device avoids the disturb problem and the collision between write and read operations in a DP-SRAM cell or a 2P-SRAM cell. The semiconductor device 1 includes a write word line WLA and a read word line WLB each coupled to memory cells 3. A read operation activates the read word line WLB corresponding to the selected memory cell 3. A write operation activates the write word line WLA corresponding to the selected memory cell 3. The selected write word line WLA is activated after activation of the selected read word line WLB in an operation cycle that performs both read and write operations.
    Type: Grant
    Filed: October 2, 2014
    Date of Patent: December 15, 2015
    Assignee: Renesas Electronics Corporation
    Inventors: Yuichiro Ishii, Yoshikazu Saito, Shinji Tanaka, Koji Nii
  • Patent number: 9123435
    Abstract: The invention provides a semiconductor integrated circuit device provided with an SRAM that satisfies the requirements for both the SNM and the write margin with a low supply voltage. The semiconductor integrated circuit device include: multiple static memory cells provided in correspondence with multiple word lines and multiple complimentary bit lines; multiple memory cell power supply lines that each supply an operational voltage to each of the multiple memory cells connected to the multiple complimentary bit lines each; multiple power supply circuits comprised of resistive units that each supply a power supply voltage to the memory cell power supply lines each; and a pre-charge circuit that supplies a pre-charge voltage corresponding to the power supply voltage to the complimentary bit lines, wherein the memory cell power supply lines are made to have coupling capacitances to thereby transmit a write signal on corresponding complimentary bit lines.
    Type: Grant
    Filed: May 1, 2013
    Date of Patent: September 1, 2015
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Noriaki Maeda, Yoshihiro Shinozaki, Masanao Yamaoka, Yasuhisa Shimazaki, Masanori Isoda, Koji Nii
  • Publication number: 20150023091
    Abstract: A semiconductor device avoids the disturb problem and the collision between write and read operations in a DP-SRAM cell or a 2P-SRAM cell. The semiconductor device 1 includes a write word line WLA and a read word line WLB each coupled to memory cells 3. A read operation activates the read word line WLB corresponding to the selected memory cell 3. A write operation activates the write word line WLA corresponding to the selected memory cell 3. The selected write word line WLA is activated after activation of the selected read word line WLB in an operation cycle that performs both read and write operations.
    Type: Application
    Filed: October 2, 2014
    Publication date: January 22, 2015
    Applicant: Renesas Electronics Corporation
    Inventors: Yuichiro Ishii, Yoshikazu SAITO, Shinji TANAKA, Koji NII
  • Patent number: 8879334
    Abstract: A semiconductor device avoids the disturb problem and the collision between write and read operations in a DP-SRAM cell or a 2P-SRAM cell. The semiconductor device 1 includes a write word line WLA and a read word line WLB each coupled to memory cells 3. A read operation activates the read word line WLB corresponding to the selected memory cell 3. A write operation activates the write word line WLA corresponding to the selected memory cell 3. The selected write word line WLA is activated after activation of the selected read word line WLB in an operation cycle that performs both read and write operations.
    Type: Grant
    Filed: January 25, 2013
    Date of Patent: November 4, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Yuichiro Ishii, Yoshikazu Saito, Shinji Tanaka, Koji Nii
  • Publication number: 20140293680
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Application
    Filed: April 28, 2014
    Publication date: October 2, 2014
    Applicant: Renesas Electronics Corporation
    Inventors: Koji NII, Shigeki OHBAYASHI, Yasumasa TSUKAMOTO, Makoto YABUUCHI
  • Publication number: 20140191338
    Abstract: In a region just below an access gate electrode in an SRAM memory cell, a second halo region is formed adjacent to a source-drain region and a first halo region is formed adjacent to a first source-drain region. In a region just below a drive gate electrode, a third halo region is formed adjacent to the third source-drain region and a fourth halo region is formed adjacent to a fourth source-drain region. The second halo region is set to have an impurity concentration higher than the impurity concentration of the first halo region. The third halo region is set to have an impurity concentration higher than the impurity concentration of the fourth halo region. The impurity concentration of the first halo region and the impurity concentration of the fourth halo region are different from each other.
    Type: Application
    Filed: July 29, 2011
    Publication date: July 10, 2014
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Koji Nii, Makoto Yabuuchi, Yasumasa Tsukamoto, Kengo Masuda
  • Patent number: 8743645
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Grant
    Filed: December 14, 2011
    Date of Patent: June 3, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Publication number: 20140126278
    Abstract: Cell power supply lines are arranged for memory cell columns, and adjust impedances or voltage levels of the cell power supply lines according to the voltage levels of bit lines in the corresponding columns, respectively. In the data write operation, the cell power supply line is forced into a floating state according to the bit line potential on a selected column and has the voltage level changed, and a latching capability of a selected memory cell is reduced to write data fast. Even with a low power supply voltage, a static semiconductor memory device that can stably perform write and read of data is implemented.
    Type: Application
    Filed: January 9, 2014
    Publication date: May 8, 2014
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Koji NII, Shigeki OBAYASHI, Hiroshi MAKINO, Koichiro ISHIBASHI, Hirofumi SHINOHARA