Patents by Inventor Makoto Kitayama

Makoto Kitayama 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: 20210343323
    Abstract: Methods, systems, and devices for refresh command management are described. A memory device may conduct a refresh operation to preserve the integrity of data stored to one or more memory cells. In some examples, the frequency of refresh operations conducted may be based on the memory device's temperature and may be initiated based on one or more commands received from an external device (e.g., a host device). Each command may be transmitted by the host device at a defined rate, which may impact the rate at which the memory device conducts one or more refresh operations. The memory device may postpone or skip at least a portion of one or more refresh operations based on one or more operating parameters of the memory device.
    Type: Application
    Filed: May 13, 2021
    Publication date: November 4, 2021
    Inventors: Nathaniel J. Meier, James S. Rehmeyer, Sang-Kyun Park, Makoto Kitayama
  • Patent number: 11017834
    Abstract: Methods, systems, and devices for refresh command management are described. A memory device may conduct a refresh operation to preserve the integrity of data stored to one or more memory cells. In some examples, the frequency of refresh operations conducted may be based on the memory device's temperature and may be initiated based on one or more commands received from an external device (e.g., a host device). Each command may be transmitted by the host device at a defined rate, which may impact the rate at which the memory device conducts one or more refresh operations. The memory device may postpone or skip at least a portion of one or more refresh operations based on one or more operating parameters of the memory device.
    Type: Grant
    Filed: November 30, 2018
    Date of Patent: May 25, 2021
    Assignee: Micron Technology, Inc.
    Inventors: Nathaniel J. Meier, James S. Rehmeyer, Sang-Kyun Park, Makoto Kitayama
  • Publication number: 20200176047
    Abstract: Methods, systems, and devices for refresh command management are described. A memory device may conduct a refresh operation to preserve the integrity of data stored to one or more memory cells. In some examples, the frequency of refresh operations conducted may be based on the memory device's temperature and may be initiated based on one or more commands received from an external device (e.g., a host device). Each command may be transmitted by the host device at a defined rate, which may impact the rate at which the memory device conducts one or more refresh operations. The memory device may postpone or skip at least a portion of one or more refresh operations based on one or more operating parameters of the memory device.
    Type: Application
    Filed: November 30, 2018
    Publication date: June 4, 2020
    Inventors: Nathaniel J. Meier, James S. Rehmeyer, Sang-Kyun Park, Makoto Kitayama
  • Publication number: 20190304516
    Abstract: Apparatuses and methods for coupling data lines in a memory device are disclosed. An example apparatus includes first and second local IO lines, first and second global IO lines, and a control circuit. The control circuit is configured in a write operation to bring the first local IO line and the first global IO line to one of first and second combinations in logic level and the second local IO line and the second global IO line to the other of the first and second combinations in logic level, and further configured in a read operation to cause the first local IO line and the first global IO line into to one of third and fourth combinations in logic level and the second local IO line and the second global IO line to the other of the third and fourth combinations in logic level.
    Type: Application
    Filed: March 28, 2018
    Publication date: October 3, 2019
    Applicant: Micron Technology, Inc.
    Inventors: Hideo Shimizu, Makoto Kitayama, Mototsugu Fujimitsu
  • Patent number: 9263110
    Abstract: A semiconductor memory device includes a plurality of memory banks each including a plurality of circuit areas selected based on an address signal, any one of which is selected by a corresponding bank selective signal (source transistor control signals), and a selective activation circuit that, from among circuit areas included in a memory bank that is selected based on the bank selective signal, activates any one of the circuit areas based on the address signal, and deactivates at least one of rest of the circuit areas. According to the present invention, the power consumption can be reduced in an active state by a dynamic power control in response to an address signal, not by entire power control by an external command.
    Type: Grant
    Filed: September 19, 2013
    Date of Patent: February 16, 2016
    Assignee: PS4 Luxco S.a.r.l.
    Inventor: Makoto Kitayama
  • Publication number: 20140016427
    Abstract: A semiconductor memory device includes a plurality of memory banks each including a plurality of circuit areas selected based on an address signal, any one of which is selected by a corresponding bank selective signal (source transistor control signals), and a selective activation circuit that, from among circuit areas included in a memory bank that is selected based on the bank selective signal, activates any one of the circuit areas based on the address signal, and deactivates at least one of rest of the circuit areas. According to the present invention, the power consumption can be reduced in an active state by a dynamic power control in response to an address signal, not by entire power control by an external command.
    Type: Application
    Filed: September 19, 2013
    Publication date: January 16, 2014
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Makoto KITAYAMA
  • Patent number: 8588023
    Abstract: A semiconductor memory device includes a plurality of memory banks each including a plurality of circuit areas selected based on an address signal, any one of which is selected by a corresponding bank selective signal (source transistor control signals), and a selective activation circuit that, from among circuit areas included in a memory bank that is selected based on the bank selective signal, activates any one of the circuit areas based on the address signal, and deactivates at least one of rest of the circuit areas. According to the present invention, the power consumption can be reduced in an active state by a dynamic power control in response to an address signal, not by entire power control by an external command.
    Type: Grant
    Filed: May 4, 2012
    Date of Patent: November 19, 2013
    Assignee: Elpida Memory, Inc.
    Inventor: Makoto Kitayama
  • Patent number: 8565036
    Abstract: A semiconductor memory device includes a plurality of word lines wired in a first direction, a plurality of bit lines wired in a direction crossing the first direction, a memory cell array including a plurality of DRAM cells provided corresponding to intersections between the word lines and the bit lines, a word line driver which drives the word lines, and a plurality of word line potential stabilization transistors connected to the respective word lines and disposed on an opposite side of the word line driver with the memory cell array sandwiched between the word line potential stabilization transistors and the word line driver, each word line potential stabilization transistor turning on when the word line adjacent to a relevant one of the word lines is selected, thereby connecting the relevant word line to a non-selected potential, and turning off when the relevant word line is selected.
    Type: Grant
    Filed: May 11, 2011
    Date of Patent: October 22, 2013
    Assignee: Elpida Memory, Inc.
    Inventor: Makoto Kitayama
  • Publication number: 20120224447
    Abstract: A semiconductor memory device includes a plurality of memory banks each including a plurality of circuit areas selected based on an address signal, any one of which is selected by a corresponding bank selective signal (source transistor control signals), and a selective activation circuit that, from among circuit areas included in a memory bank that is selected based on the bank selective signal, activates any one of the circuit areas based on the address signal, and deactivates at least one of rest of the circuit areas. According to the present invention, the power consumption can be reduced in an active state by a dynamic power control in response to an address signal, not by entire power control by an external command.
    Type: Application
    Filed: May 4, 2012
    Publication date: September 6, 2012
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Makoto KITAYAMA
  • Publication number: 20110286262
    Abstract: A semiconductor memory device includes a plurality of word lines wired in a first direction, a plurality of bit lines wired in a direction crossing the first direction, a memory cell array including a plurality of DRAM cells provided corresponding to intersections between the word lines and the bit lines, a word line driver which drives the word lines, and a plurality of word line potential stabilization transistors connected to the respective word lines and disposed on an opposite side of the word line driver with the memory cell array sandwiched between the word line potential stabilization transistors and the word line driver, each word line potential stabilization transistor turning on when the word line adjacent to a relevant one of the word lines is selected, thereby connecting the relevant word line to a non-selected potential, and turning off when the relevant word line is selected.
    Type: Application
    Filed: May 11, 2011
    Publication date: November 24, 2011
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Makoto Kitayama
  • Patent number: 7864610
    Abstract: A sense amplifier controlling circuit for controlling a sense amplifier in a semiconductor memory, which amplifies differential electric potential of a pair of bit lines to which memory cells are connected by sequentially operating a CMOS flip-flop and a preamplifier performing an amplification operation different from each other, controls the sense amplifier, and activate the preamplifier at an early operation stage of the CMOS flip-flop and the preamplifier independently of activation of the CMOS flip-flop during the amplification operation of the CMOS flip-flop.
    Type: Grant
    Filed: October 27, 2008
    Date of Patent: January 4, 2011
    Assignee: Elpida Memory, Inc.
    Inventor: Makoto Kitayama
  • Publication number: 20100149900
    Abstract: A semiconductor memory device includes a plurality of memory banks each including a plurality of circuit areas selected based on an address signal, any one of which is selected by a corresponding bank selective signal (source transistor control signals), and a selective activation circuit that, from among circuit areas included in a memory bank that is selected based on the bank selective signal, activates any one of the circuit areas based on the address signal, and deactivates at least one of rest of the circuit areas. According to the present invention, the power consumption can be reduced in an active state by a dynamic power control in response to an address signal, not by entire power control by an external command.
    Type: Application
    Filed: December 16, 2009
    Publication date: June 17, 2010
    Applicant: Elpida Memory, Inc.
    Inventor: Makoto KITAYAMA
  • Patent number: 7656220
    Abstract: Disclosed are a semiconductor device capable of reducing the number of program fuses used therein, and a fuse circuit selection method capable of reducing the number of program fuses. The semiconductor device includes: a fuse circuit (11) and an entire inversion fuse circuit (12), each of which includes plural program fuses, and which store desired addresses based on cutting patterns of the plural program fuses, wherein the fuse circuit (11) and the entire inversion fuse circuit (12) are configured to be capable of storing addresses different from each other based on the same cutting pattern. As described above, since plural types of the cutting patterns of the program fuses exist even in the same address, the fuse circuit for use is appropriately selected, thus it is made possible to reduce the number of fuse elements to be cut as a whole. Thus, manufacturing cost of the semiconductor device can be reduced, and in addition, it is made possible to enhance reliability of the semiconductor device.
    Type: Grant
    Filed: December 15, 2005
    Date of Patent: February 2, 2010
    Assignee: Elpida Memory, Inc.
    Inventors: Yosuke Kawamata, Makoto Kitayama
  • Publication number: 20090109779
    Abstract: A sense amplifier controlling circuit for controlling a sense amplifier in a semiconductor memory, which amplifies differential electric potential of a pair of bit lines to which memory cells are connected by sequentially operating a CMOS flip-flop and a preamplifier performing an amplification operation different from each other, controls the sense amplifier, and activate the preamplifier at an early operation stage of the CMOS flip-flop and the preamplifier independently of activation of the CMOS flip-flop during the amplification operation of the CMOS flip-flop.
    Type: Application
    Filed: October 27, 2008
    Publication date: April 30, 2009
    Inventor: Makoto Kitayama
  • Patent number: 7417479
    Abstract: A duty detection circuit is provided with a main circuit unit that includes at least a first capacitor that is discharged during the time period in which the clock signal is at a high level and charged during the time period in which the clock signal is at a low level, and a second capacitor that is charged during the time period in which the clock signal is at a high level and discharged during the time period in which the clock signal is at a low level, with the main circuit unit alternately charging or discharging the first and second capacitors in synchrony with the clock signal; and a duty correction signal generator for detecting the potential difference of the first and second capacitors and outputting a duty correction signal based on the potential difference.
    Type: Grant
    Filed: April 12, 2006
    Date of Patent: August 26, 2008
    Assignee: Elpida Memory, Inc.
    Inventor: Makoto Kitayama
  • Publication number: 20060232311
    Abstract: A duty detection circuit is provided with a main circuit unit that includes at least a first capacitor that is discharged during the time period in which the clock signal is at a high level and charged during the time period in which the clock signal is at a low level, and a second capacitor that is charged during the time period in which the clock signal is at a high level and discharged during the time period in which the clock signal is at a low level, with the main circuit unit alternately charging or discharging the first and second capacitors in synchrony with the clock signal; and a duty correction signal generator for detecting the potential difference of the first and second capacitors and outputting a duty correction signal based on the potential difference.
    Type: Application
    Filed: April 12, 2006
    Publication date: October 19, 2006
    Inventor: Makoto Kitayama
  • Publication number: 20060125549
    Abstract: Disclosed are a semiconductor device capable of reducing the number of program fuses used therein, and a fuse circuit selection method capable of reducing the number of program fuses. The semiconductor device includes: a fuse circuit (11) and an entire inversion fuse circuit (12), each of which includes plural program fuses, and which store desired addresses based on cutting patterns of the plural program fuses, wherein the fuse circuit (11) and the entire inversion fuse circuit (12) are configured to be capable of storing addresses different from each other based on the same cutting pattern. As described above, since plural types of the cutting patterns of the program fuses exist even in the same address, the fuse circuit for use is appropriately selected, thus it is made possible to reduce the number of fuse elements to be cut as a whole. Thus, manufacturing cost of the semiconductor device can be reduced, and in addition, it is made possible to enhance reliability of the semiconductor device.
    Type: Application
    Filed: December 15, 2005
    Publication date: June 15, 2006
    Inventors: Yosuke Kawamata, Makoto Kitayama
  • Publication number: 20060125548
    Abstract: Disclosed are a semiconductor device capable of reducing the number of program fuses used therein, and a fuse circuit selection method. The semiconductor device includes at least one first fuse circuit including: a storage circuit group which stores a desired address based on a cutting pattern of the plural program fuses; a hit detection unit which detects a match between the address stored in the storage circuit group and a selected address; and a use determination unit which activates the hit detection unit in response to the fact that at least one of the program fuses is cut. As described above, the first fuse circuit determines whether the first fuse circuit is in a used state or in an unused state depending on whether or not the program fuse itself is cut. Accordingly, an enable fuse becomes unnecessary.
    Type: Application
    Filed: December 15, 2005
    Publication date: June 15, 2006
    Inventors: Makoto Kitayama, Yosuke Kawamata
  • Publication number: 20010005325
    Abstract: A semiconductor memory device according to the invention comprises a first memory cell region, a second memory cell region, and a sense-amplifier row region disposed between the first and second memory cell regions, wherein the sense-amplifier row region has therein a plurality of transistor rows constituting a plurality of sense-amplifiers, at least one power-supply side sense-amplifier driver transistor disposed on the side f the first memory cell region of the plurality of transistor rows, and at least one ground side sense-amplifier driver transistor disposed on the side of the second memory cell region of the plurality of transistor rows.
    Type: Application
    Filed: December 12, 2000
    Publication date: June 28, 2001
    Applicant: NEC Corporation
    Inventors: Makoto Kitayama, Yukio Fukuzo, Takashi Obara, Yasuji Koshikawa, Toru Chonan, Yasushi Matsubara, Hideki Mitou
  • Patent number: 6137736
    Abstract: The present invention provides a semiconductor memory device having a block selective line selecting circuit connected to a plurality of block selective common lines, each of which is commonly connected to both corresponding normal and redundant memory cell blocks in normal and redundant memory cell arrays, wherein the block selective line selecting circuit is switched into a first state to permit transmissions of decoded normal row address signals having informations of designating a normal row address to which a normal memory cell to be selected belongs when a non-defective normal memory cell is selected in the normal memory cell array, and also the block selective line selecting circuit is switched into a second state to permit transmissions of decoded redundant row address signals having informations of designating a redundant row address to which a redundant memory cell to be selected belongs when a defective normal memory cell is selected in the normal memory cell array.
    Type: Grant
    Filed: December 28, 1998
    Date of Patent: October 24, 2000
    Assignee: NEC Corporation
    Inventor: Makoto Kitayama