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).
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Publication number: 20210343323Abstract: 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: ApplicationFiled: May 13, 2021Publication date: November 4, 2021Inventors: Nathaniel J. Meier, James S. Rehmeyer, Sang-Kyun Park, Makoto Kitayama
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Patent number: 11017834Abstract: 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: GrantFiled: November 30, 2018Date of Patent: May 25, 2021Assignee: Micron Technology, Inc.Inventors: Nathaniel J. Meier, James S. Rehmeyer, Sang-Kyun Park, Makoto Kitayama
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Publication number: 20200176047Abstract: 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: ApplicationFiled: November 30, 2018Publication date: June 4, 2020Inventors: Nathaniel J. Meier, James S. Rehmeyer, Sang-Kyun Park, Makoto Kitayama
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Publication number: 20190304516Abstract: 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: ApplicationFiled: March 28, 2018Publication date: October 3, 2019Applicant: Micron Technology, Inc.Inventors: Hideo Shimizu, Makoto Kitayama, Mototsugu Fujimitsu
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Patent number: 9263110Abstract: 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: GrantFiled: September 19, 2013Date of Patent: February 16, 2016Assignee: PS4 Luxco S.a.r.l.Inventor: Makoto Kitayama
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Publication number: 20140016427Abstract: 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: ApplicationFiled: September 19, 2013Publication date: January 16, 2014Applicant: ELPIDA MEMORY, INC.Inventor: Makoto KITAYAMA
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Patent number: 8588023Abstract: 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: GrantFiled: May 4, 2012Date of Patent: November 19, 2013Assignee: Elpida Memory, Inc.Inventor: Makoto Kitayama
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Patent number: 8565036Abstract: 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: GrantFiled: May 11, 2011Date of Patent: October 22, 2013Assignee: Elpida Memory, Inc.Inventor: Makoto Kitayama
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Publication number: 20120224447Abstract: 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: ApplicationFiled: May 4, 2012Publication date: September 6, 2012Applicant: ELPIDA MEMORY, INC.Inventor: Makoto KITAYAMA
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Publication number: 20110286262Abstract: 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: ApplicationFiled: May 11, 2011Publication date: November 24, 2011Applicant: ELPIDA MEMORY, INC.Inventor: Makoto Kitayama
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Patent number: 7864610Abstract: 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: GrantFiled: October 27, 2008Date of Patent: January 4, 2011Assignee: Elpida Memory, Inc.Inventor: Makoto Kitayama
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Publication number: 20100149900Abstract: 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: ApplicationFiled: December 16, 2009Publication date: June 17, 2010Applicant: Elpida Memory, Inc.Inventor: Makoto KITAYAMA
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Patent number: 7656220Abstract: 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: GrantFiled: December 15, 2005Date of Patent: February 2, 2010Assignee: Elpida Memory, Inc.Inventors: Yosuke Kawamata, Makoto Kitayama
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Publication number: 20090109779Abstract: 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: ApplicationFiled: October 27, 2008Publication date: April 30, 2009Inventor: Makoto Kitayama
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Patent number: 7417479Abstract: 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: GrantFiled: April 12, 2006Date of Patent: August 26, 2008Assignee: Elpida Memory, Inc.Inventor: Makoto Kitayama
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Publication number: 20060232311Abstract: 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: ApplicationFiled: April 12, 2006Publication date: October 19, 2006Inventor: Makoto Kitayama
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Publication number: 20060125549Abstract: 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: ApplicationFiled: December 15, 2005Publication date: June 15, 2006Inventors: Yosuke Kawamata, Makoto Kitayama
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Publication number: 20060125548Abstract: 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: ApplicationFiled: December 15, 2005Publication date: June 15, 2006Inventors: Makoto Kitayama, Yosuke Kawamata
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Publication number: 20010005325Abstract: 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: ApplicationFiled: December 12, 2000Publication date: June 28, 2001Applicant: NEC CorporationInventors: Makoto Kitayama, Yukio Fukuzo, Takashi Obara, Yasuji Koshikawa, Toru Chonan, Yasushi Matsubara, Hideki Mitou
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Patent number: 6137736Abstract: 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: GrantFiled: December 28, 1998Date of Patent: October 24, 2000Assignee: NEC CorporationInventor: Makoto Kitayama