Patents by Inventor Kazuhiko Kajigaya

Kazuhiko Kajigaya 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: 8964483
    Abstract: A semiconductor device is disclosed in which a plurality of memory cores are provided on a semiconductor chip. Each of the memory cores comprises: first and second circuit regions and a first and second through electrode groups. a first power supply is supplied in the first circuit region in which a data bus for parallel data is driven, and a second power supply separated from the first power supply is supplied in the second circuit region in which the parallel data and serial data are bidirectionally converted. The first through electrode group includes through electrodes supplying the first power supply to the first circuit region, and the second through electrode group includes through electrodes supplying the second power supply to the second circuit region.
    Type: Grant
    Filed: September 28, 2012
    Date of Patent: February 24, 2015
    Assignee: PS4 Luxco S.a.r.l.
    Inventors: Kazuhiko Kajigaya, Kazuo Ono, Tomonori Sekiguchi
  • Patent number: 8966153
    Abstract: A semiconductor memory device includes a plural number of data input/output pins, a plural number of banks, in each of which a plural number of the information data is stored, a selector and a control circuit. In a first access mode, the control circuit simultaneously accesses the multiple banks in response to a single read-out command or to a single write-in command from outside. In the first access mode, the selector coordinates a plurality of data input/output pins with the multiple banks in a predetermined relationship.
    Type: Grant
    Filed: November 22, 2013
    Date of Patent: February 24, 2015
    Assignee: PS4 Luxco S.a.r.l.
    Inventor: Kazuhiko Kajigaya
  • Publication number: 20150046774
    Abstract: A semiconductor device includes first and second memory cell arrays, each including a plurality of memory cells, each of which is connected between first and second terminals and is configured to be written to a first resistance state by applying a first current in a first direction between the first and second terminals and be written to a second resistance state by applying a second current in a second direction opposite to the first direction between the first and second terminals. The semiconductor device further includes an error-correction circuit and a control circuit. Additional apparatus and methods are disclosed.
    Type: Application
    Filed: August 12, 2014
    Publication date: February 12, 2015
    Inventor: Kazuhiko Kajigaya
  • Patent number: 8922025
    Abstract: There is provided a semiconductor device which includes a plurality of first through-substrate vias that are used to supply power from a first power supply and that penetrate through a substrate structure, and a plurality of second through-substrate vias that are used to supply power from a second power supply different from the first power supply and that penetrate through a substrate structure. The semiconductor device also includes a through-substrate via string composed by the first and second through-substrate vias, in which the first through-substrate vias are located adjacent to one another and the second through-substrate vias are also located adjacent to one another. The through-substrate via string is disposed in the substrate structure for extending in a first direction.
    Type: Grant
    Filed: June 10, 2013
    Date of Patent: December 30, 2014
    Assignee: PS4 Luxco S.a.r.l.
    Inventors: Kazuo Ono, Riichiro Takemura, Takamasa Suzuki, Kazuhiko Kajigaya, Akira Kotabe, Yoshimitsu Yanagawa
  • Patent number: 8917567
    Abstract: A semiconductor device includes a global bit line and a local bit line, and a switch coupled therebetween. Upon performing a precharge operation, a precharge voltage is supplied to the global bit line with turning the switch ON, so that the local bit line receives the precharge voltage through the global bit line and the switch, and after a lapse of a predetermined time, a precharge voltage is further supplied to the local bit line without an intervention of the global bit line and the switch.
    Type: Grant
    Filed: December 7, 2011
    Date of Patent: December 23, 2014
    Assignee: PS4 Luxco S.a.r.l.
    Inventors: Shinichi Takayama, Kazuhiko Kajigaya
  • Patent number: 8873307
    Abstract: A semiconductor device includes a sense amplifier, transistors selectively establishing electrical connection between the sense amplifier and a data bus, depending on address; a write amplifier connected to the data bus, an external terminal outputting data from a memory cell to outside via the sense amplifier, the transistors, and the data bus in a first operation mode and supplying data from outside to the sense amplifier via the write amplifier, the data bus, and the transistors in a second operation mode, and a control circuit supplying an electric potential to gate electrodes of first transistors that establish the electrical connection depending on the address.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: October 28, 2014
    Assignee: PS4 Luxco S.a.r.l.
    Inventor: Kazuhiko Kajigaya
  • Patent number: 8867294
    Abstract: A semiconductor device comprises a first memory cell array, a register storing information of whether or not one of the word lines in an active state exists in a unit area and storing address information, and a control circuit controlling a refresh operation for a refresh word line based on the information in the register when receiving a refresh request. When the one of the word lines in an active state does not exist, memory cells connected to the refresh word line are refreshed. When the one of the word lines in an active state exists, the one of the word lines in an active state is set into an inactive state temporarily and the memory cells connected to the refresh word line are refreshed after precharging bit lines of the memory cells.
    Type: Grant
    Filed: January 22, 2014
    Date of Patent: October 21, 2014
    Assignee: PS4 Luxco S.a.r.l.
    Inventor: Kazuhiko Kajigaya
  • Publication number: 20140293721
    Abstract: A single-ended sense amplifier circuit of the invention comprises first and second MOS transistors and first and second precharge circuits. The first MOS transistor drives the bit line to a predetermined voltage and switches connection between the bit line and a sense node and the second MOS transistor whose gate is connected to the sense node amplifies the signal via the first MOS transistor. The first precharge circuit precharges the bit line to a first potential and the second precharge circuit precharges the sense node to a second potential. Before sensing operation, the bit line is driven to the predetermined voltage when the above gate voltage is controlled to decrease. The predetermined voltage is appropriately set so that a required voltage difference at the sense node between high and low levels can be obtained near a changing point between charge transfer/distributing modes.
    Type: Application
    Filed: June 17, 2014
    Publication date: October 2, 2014
    Applicant: PS4 Luxco S.a.r.l.
    Inventors: Kazuhiko KAJIGAYA, Soichiro YOSHIDA, Yasutoshi YAMADA
  • Publication number: 20140241088
    Abstract: Disclosed herein is a semiconductor device comprising complementary pair of bit lines, memory cells connected to the bit lines, dummy cells having the same structure as the memory cells, a differential sense amplifier, an equalizing circuit equalizing potentials of the bit lines, and a control circuit. The memory cells are disconnected from the bit lines and the dummy cells are connected to the bit lines, and subsequently the bit lines are equalized by the equalizing circuit. When accessing a selected memory cell, the equalizing circuit is inactivated, a corresponding dummy cell is disconnected from the bit line, and subsequently the selected memory cell is connected to the bit line. Thereafter, the sense amplifier is activated so that potentials of the bit lines are amplified respectively.
    Type: Application
    Filed: May 8, 2014
    Publication date: August 28, 2014
    Applicant: PS4 LUXCO S.A.R.L.
    Inventor: Kazuhiko KAJIGAYA
  • Patent number: 8773935
    Abstract: Disclosed herein is a semiconductor device comprising complementary pair of bit lines, memory cells connected to the bit lines, dummy cells having the same structure as the memory cells, a differential sense amplifier, an equalizing circuit equalizing potentials of the bit lines, and a control circuit. The memory cells are disconnected from the bit lines and the dummy cells are connected to the bit lines, and subsequently the bit lines are equalized by the equalizing circuit. When accessing a selected memory cell, the equalizing circuit is inactivated, a corresponding dummy cell is disconnected from the bit line, and subsequently the selected memory cell is connected to the bit line. Thereafter, the sense amplifier is activated so that potentials of the bit lines are amplified respectively.
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: July 8, 2014
    Inventor: Kazuhiko Kajigaya
  • Publication number: 20140169111
    Abstract: A method for carrying out read and write operations in a synchronous memory device having a shared I/O, includes receiving a read command directed to a first internal memory bank during a first timeslot, activating the first internal memory bank to access read data at a read address requested by the read command, receiving a write command directed to a second internal memory bank during a second timeslot later than the first timeslot, determining whether a data collision between the read data for output to the shared I/O with normal read latency and write data to be received on the shared I/O with normal write latency would occur, and receiving the write data on the shared I/O with the normal write latency during a third timeslot later than the second timeslot.
    Type: Application
    Filed: February 10, 2014
    Publication date: June 19, 2014
    Applicant: Elpida Memory, Inc.
    Inventors: Kazuhiko Kajigaya, Tomonori Sekiguchi, Kazuo Ono
  • Publication number: 20140133255
    Abstract: A semiconductor device comprises a first memory cell array, a register storing information of whether or not one of the word lines in an active state exists in a unit area and storing address information, and a control circuit controlling a refresh operation for a refresh word line based on the information in the register when receiving a refresh request. When the one of the word lines in an active state does not exist, memory cells connected to the refresh word line are refreshed. When the one of the word lines in an active state exists, the one of the word lines in an active state is set into an inactive state temporarily and the memory cells connected to the refresh word line are refreshed after precharging bit lines of the memory cells.
    Type: Application
    Filed: January 22, 2014
    Publication date: May 15, 2014
    Inventor: Kazuhiko KAJIGAYA
  • Patent number: 8717805
    Abstract: A semiconductor random access memory device includes a memory cell including a resistor whose resistance varies by formation and disappearance of a filament due to an oxidation-reduction reaction of metal ions, a memory area configured to include a first memory area operable in a nonvolatile mode in which a stored content thereof is not lost by a power-off event, and a second memory area operable in a volatile mode in which the stored content thereof is lost by the power-off event, each of the first memory area and the second memory area including the plurality of the memory cells, a register circuit that stores information including a first address information indicating the first memory area, and a second address information indicating the second memory area, and a control circuit that controls the nonvolatile mode, and the volatile mode, with reference to the information stored in the register circuit.
    Type: Grant
    Filed: April 12, 2013
    Date of Patent: May 6, 2014
    Assignee: Elpida Memory, Inc.
    Inventor: Kazuhiko Kajigaya
  • Publication number: 20140085997
    Abstract: A method includes accessing a memory cell to allow the memory cell to output data stored therein onto a local bit line; transferring, in response to a data read mode, a signal related to the data from the local bit line to a global bit line; and restoring, in response to a refresh mode, the data into the memory cell while keeping the local bit line electrically isolated from the global bit line.
    Type: Application
    Filed: November 29, 2013
    Publication date: March 27, 2014
    Applicant: Elpida Memory, Inc.
    Inventors: Kazuhiko KAJIGAYA, Yasutoshi YAMADA
  • Publication number: 20140082306
    Abstract: A semiconductor memory device includes a plural number of data input/output pins, a plural number of banks, in each of which a plural number of the information data is stored, a selector and a control circuit. In a first access mode, the control circuit simultaneously accesses the multiple banks in response to a single read-out command or to a single write-in command from outside. In the first access mode, the selector coordinates a plurality of data input/output pins with the multiple banks in a predetermined relationship.
    Type: Application
    Filed: November 22, 2013
    Publication date: March 20, 2014
    Inventor: Kazuhiko KAJIGAYA
  • Publication number: 20140078805
    Abstract: A device includes first and second regions including first and second amplifiers, respectively and a memory cell array region formed between the first and second regions and includes first and second conductive layers each extending in a first direction, and a plurality of first pillar elements arranged in line in the first direction on the first conductive layer, each of the first pillar elements being coupled to the first conductive layer at one end thereof, and the first pillar elements comprising a plurality of first elements and a second element, and a plurality of second pillar elements arranged in line in the first direction on the second conductive layer, each of the second pillar elements being coupled to the second conductive layer at one end thereof, and the second pillar elements comprising a plurality of third elements and a fourth element.
    Type: Application
    Filed: November 22, 2013
    Publication date: March 20, 2014
    Applicant: Elpida Memory, Inc.
    Inventor: Kazuhiko KAJIGAYA
  • Patent number: 8675419
    Abstract: A semiconductor device includes a delay buffer, and a pipeline control circuit. The pipeline control circuit controls the delay buffer to hold read data from outputting to a read/write bus for each of banks based on a read command to the each bank while the pipeline control circuit controlling the delay buffer to output write data to the read/write bus, when a next command to the each bank is a write command for the write data. The read/write bus is common to the banks.
    Type: Grant
    Filed: January 3, 2011
    Date of Patent: March 18, 2014
    Assignee: Elpida Memory, Inc.
    Inventors: Kazuhiko Kajigaya, Tomonori Sekiguchi, Kazuo Ono
  • Publication number: 20140056063
    Abstract: A method includes performing a read operation on a memory cell of a device including a sensing line, a bit line coupled to the memory cell, a first transistor having a source-drain path coupled between the sensing line and the bit line, and a second transistor having a gate coupled to sense the sensing line, the performing including providing a gate of the first transistor with a first voltage, providing the sensing line with a second voltage, and providing the bit line with a third voltage, the third voltage being independent from the second voltage.
    Type: Application
    Filed: October 28, 2013
    Publication date: February 27, 2014
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Kazuhiko Kajigaya
  • Publication number: 20140032941
    Abstract: Disclosed herein is a device that includes: a memory cell array including a plurality of memory cells, the memory cell array operates on a first internal voltage; a peripheral circuit accessing selected one or ones of the memory cells, the peripheral circuit operates on a second internal voltage; a first internal voltage generation circuit that supplies the first internal voltage to the memory cell array; and a second internal voltage generation circuit that supplies the second internal voltage to the peripheral circuit. The second internal voltage generation circuit sets the second internal voltage to a first voltage value in a first mode, and to a second voltage value that is different from the first voltage value in a second mode. The first internal voltage generation circuit sets the first internal voltage to a third voltage value in both the first and second modes.
    Type: Application
    Filed: July 15, 2013
    Publication date: January 30, 2014
    Inventors: Kazuhiko KAJIGAYA, Takamasa SUZUKI
  • Patent number: 8638630
    Abstract: A device includes a plurality of restoring circuits each provided for an associated one of local bit lines, remaining one or ones of the restoring circuits other than the restoring circuit provided for the selected one of the local bit lines being configured to receive, through remaining one or ones of the local bit lines, data that is or are read out from a memory cell or cells connected to the remaining one or ones of the local bit lines, and restore, through the remaining one or ones of the local bit lines, the data into the memory cell or cells connected to the remaining one or ones of the local bit lines.
    Type: Grant
    Filed: September 15, 2012
    Date of Patent: January 28, 2014
    Assignee: Elpida Memory, Inc.
    Inventors: Kazuhiko Kajigaya, Yasutoshi Yamada