Patents by Inventor Daisaburo Takashima
Daisaburo Takashima 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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Patent number: 8335967Abstract: A memory system that can efficiently relieve a large number of defective bits with a small number of redundant bits is provided in a Flash-EEPROM nonvolatile memory. A memory system according to an embodiment of the present invention comprises a Flash-EEPROM memory in which a plurality of memory cells having a floating gate or a charge trapping layer and capable of electrically erasing and writing data are arranged; a control circuit that controls a cache memory and the Flash-EEPROM memory; and an interface circuit that communicates with outside, wherein a plurality of group data and a plurality of flag data for storing presence of inversion of all bits of respective group data are stored in a memory area of the Flash-EEPROM memory.Type: GrantFiled: August 7, 2008Date of Patent: December 18, 2012Assignee: Kabushiki Kaisha ToshibaInventor: Daisaburo Takashima
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Patent number: 8331191Abstract: According to one embodiment, a semiconductor integrated circuit device includes an output circuit which includes an inverter having a first transistor and a second transistor whose current paths are series-connected between a first power supply voltage and a second power supply voltage, a first diode circuit one end of which is connected to the first power supply voltage, and the other end of which is connected to a control terminal of the first transistor, and an adjustment circuit which forms a current path for discharging a charge of the control terminal of the first transistor to the second power supply voltage when an input clock is at a first level.Type: GrantFiled: September 15, 2011Date of Patent: December 11, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Takeshi Hioka, Daisaburo Takashima
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Publication number: 20120243307Abstract: According to one embodiment, a phase change memory includes a memory cell, a select transistor, and a memory cell array. The memory cell includes a chalcogenide wiring, resistance wirings and a cell transistor. The chalcogenide wiring becomes a heater. One end of a plurality of memory cells with sources and drains connected in series is connected to a source of the select transistor. The bit line is connected a drain of the select transistor. The memory cell array is obtained by forming a memory cell string.Type: ApplicationFiled: March 19, 2012Publication date: September 27, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventor: Daisaburo Takashima
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Publication number: 20120241837Abstract: According to one embodiment, a non-volatile memory includes a first non-volatile memory cell and a first selected transistor. A first cell block is formed by connecting a plurality of first non-volatile memory cells in series. An area S1 of the first insulating film at which the first floating gate is in contact with the first silicon channel is larger than an area S2 of the second insulating film at which the first floating gate is in contact with the first gate electrode.Type: ApplicationFiled: March 16, 2012Publication date: September 27, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventor: Daisaburo TAKASHIMA
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Patent number: 8274846Abstract: A reference voltage generation circuit includes a first node settable at a reference voltage to be any one of a plurality of voltage levels, a second node set at a pre-charge voltage, first and second switches connected in series between the first and second nodes, a plurality of capacitors, each capacitor comprising a first end connected to a connection node between the first and second switches and a second end settable at an independent voltage level, a switch controller configured to turn off the first switch and turn on the second switch in an initial state, and then to turn off the second switch, and then to turn on the first switch, and a voltage controller configured to individually set a voltage at the second end of each capacitor after the first switch is turned on.Type: GrantFiled: January 5, 2010Date of Patent: September 25, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Hidehiro Shiga, Daisaburo Takashima
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Patent number: 8259513Abstract: An internal voltage generator according to an embodiment generates a reference voltage used for detecting data stored in a semiconductor memory. A first AD converter is configured to convert an external voltage supplied to the semiconductor memory into a first digital value. A second AD converter is configured to convert a temperature characteristic voltage that changes depending on a temperature of the semiconductor memory into a second digital value. An adder is configured to receive a reference voltage trimming address that specifies the reference voltage, the first digital value, and the second digital value, and to output a third digital value obtained by performing a weighted addition of the reference voltage trimming address, the first digital value, and the second digital value. A driver is configured to output the reference voltage responding to the third digital value.Type: GrantFiled: July 13, 2010Date of Patent: September 4, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Ryu Ogiwara, Daisaburo Takashima
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Patent number: 8255762Abstract: This disclosure concerns a memory including: a first memory region including memory groups including a plurality of memory cells, addresses being respectively allocated for the memory groups, the memory groups respectively being units of data erase operations; a second memory region temporarily storing therein data read from the first memory region or temporarily storing therein data to be written to the first memory region; a read counter storing therein a data read count for each memory group; an error-correcting circuit calculating an error bit count of the read data; and a controller performing a refresh operation, in which the read data stored in one of the memory groups is temporarily stored in the second memory region and is written back the read data to the same memory group, when the error bit count exceeds a first threshold or when the data read count exceeds a second threshold.Type: GrantFiled: November 16, 2011Date of Patent: August 28, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Yasushi Nagadomi, Daisaburo Takashima, Kosuke Hatsuda
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Patent number: 8248835Abstract: Semiconductor memory contains memory cells having ferroelectric capacitors and cell transistors, bit lines connected to memory cells, word lines connected to gate electrodes of cell transistors, plate lines connected to one of two electrodes of ferroelectric capacitors, sense amplifiers connected between each pair of bit lines. Further, a test pad is provided in order to apply an external voltage to each of bit lines, test transistors are provided corresponding to bit lines respectively, each of test transistors is connected between the test pad and each of bit lines, a fatigue test bias circuit is connected to a first node located between the test pad and test transistors. Test transistors are shared in a first test to apply a first voltage to ferroelectric capacitors from an outside via the test pad and a second test to apply a second voltage to ferroelectric capacitors from the fatigue test bias circuit.Type: GrantFiled: March 5, 2010Date of Patent: August 21, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Tadashi Miyakawa, Daisaburo Takashima
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Patent number: 8238137Abstract: A ferroelectric random access memory device has a first bit line, a first ferroelectric capacitor, a second bit line, a second ferroelectric capacitor and a first to fourth MOS transistor. The first bit line is changed to a first data potential according to first data stored in the first ferroelectric capacitor, the second bit line is changed to a second data potential according to second data obtained by inverting a logic of the first data, and then the second MOS transistor and the fourth MOS transistor are turned on.Type: GrantFiled: September 17, 2009Date of Patent: August 7, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Daisuke Hashimoto, Daisaburo Takashima
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Publication number: 20120179942Abstract: To provide a memory system which determines a memory state such as an exhaustion level and allows a memory to be efficiently used. The memory system includes a NAND type flash memory 1 in which data can be electrically written/erased, a nonvolatile memory 2 which counts the number of erase operations of the NAND type flash memory 1 and retains the number of erase operations and a maximum number of erase operations, and a controller 3 which has a connection interface 31 to be given a self-diagnosis command from a computer 4, and retrieves the number of erase operations and the maximum number of erase operations from the nonvolatile memory 2 based on the self-diagnosis command and outputs the number of erase operations and the maximum number of erase operations to the computer 4 through the connection interface 31.Type: ApplicationFiled: March 22, 2012Publication date: July 12, 2012Applicant: Kabushiki Kaisha ToshibaInventors: Yasushi NAGADOMI, Daisaburo Takashima, Kosuke Hatsuda, Shinichi Kanno
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Publication number: 20120179863Abstract: A memory system includes a plurality of storage groups, each of which includes a nonvolatile first storing unit and a second storing unit as a buffer memory of the first storing unit and is capable of performing data transfer between the first storing unit and the second storing unit, and a plurality of MPUs. A first control for data transfer between the host device and the first storing unit via the second storing unit for one of the storage groups and a second control including a control for maintenance of the first storing unit for other storage groups are allocated to the MPUs to be performed independently by the MPUs.Type: ApplicationFiled: March 21, 2012Publication date: July 12, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Kosuke Hatsuda, Daisaburo Takashima
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Patent number: 8218372Abstract: According to one embodiment, a first node is connected to a gate of a second PMOS and a gate of a second NMOS, a second node is connected to a gate of a first PMOS and a gate of a first NMOS, a gate of the first transistor is connected to a first signal line, a source of a first transistor is connected to the first node, and a drain of the first transistor is connected to the second node, a gate of a second transistor is connected to the second node, a source of the second transistor is connected to a third node, and a drain of the second transistor is connected to a second signal line, and a gate of a third transistor is connected to a third signal line, a source of the third transistor is connected to a fourth signal line, and a drain of the third transistor is connected to the third node.Type: GrantFiled: September 8, 2010Date of Patent: July 10, 2012Assignee: Kabushiki Kaisha ToshibaInventor: Daisaburo Takashima
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Publication number: 20120166906Abstract: The embodiments include an error correction processing unit and an error correction history recording unit. The error correction processing unit performs an error correction process based on data read from a non-volatile semiconductor memory and a second-step error correction code corresponding to the data. The error correction history recording unit records error correction history indicating whether first error correction is successful through the first error correction process, in association with unit data. When error correction history of target unit data to be read indicates that correction is not successful, the second error correction process is executed without executing the first error correction process.Type: ApplicationFiled: September 21, 2011Publication date: June 28, 2012Applicant: Kabushiki Kaisha ToshibaInventors: Yasushi NAGADOMI, Daisaburo TAKASHIMA
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Patent number: 8199554Abstract: A ferro-electric random access memory apparatus has a memory cell array in which a plurality of memory cells each formed of a ferro-electric capacitor and a transistor are arranged, word lines are disposed to select a memory cell, plate lines are disposed to apply a voltage to a first end of the ferro-electric capacitor in a memory cell, and bit lines are disposed to read cell data from a second end of the ferro-electric capacitor in the memory cell. The ferro-electric random access memory apparatus has a sense amplifier which senses and amplifies a signal read from the ferro-electric capacitor onto the bit line. The ferro-electric random access memory apparatus has a bit line potential control circuit which exercises control to pull down a voltage on an adjacent bit line adjacent to the selected bit line onto which the signal is read, before operation of the sense amplifier at time of data readout.Type: GrantFiled: September 7, 2010Date of Patent: June 12, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Daisuke Hashimoto, Daisaburo Takashima
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Patent number: 8174913Abstract: A memory includes a cell region; a spare region including a spare block; a fuse region storing remedy information necessary for an access to the spare block instead of a remedy target block, the fuse region comprising non-defective cells in the remedy target block, or including cells in a first block of the spare region; an initial reading fuse storing a block address for identifying the remedy target block or the first block allocated as the fuse region, and a selection address for selecting a region in the remedy target block or a region in the first block allocated as the fuse region; and a controller configured to acquire the remedy information from the fuse region based on the block address and the selection address, and to change the access to the remedy target block to the access to the spare block based on the remedy information.Type: GrantFiled: February 10, 2010Date of Patent: May 8, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Daisuke Hashimoto, Daisaburo Takashima
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Patent number: 8169733Abstract: A magnetic disk device includes a disk that includes a plurality of tracks and magnetically stores therein data; a magnetic head that reads and writes data on the tracks; a data writing unit that classifies sectors along one track into a plurality of sector groups and writes to a physical address of each of the sector groups data of a logical address that is different from a logical address corresponding to the physical address in same track; and a first nonvolatile memory that stores therein a conversion table of the logical address and the physical address.Type: GrantFiled: September 4, 2009Date of Patent: May 1, 2012Assignee: Kabushiki Kaisha ToshibaInventor: Daisaburo Takashima
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Patent number: 8159285Abstract: A current supply circuit according to an embodiment of the present invention includes an operational amplifier having first and second input terminals and an output terminal, a transistor having a control terminal connected to the output terminal of the operational amplifier, and having first and second main terminals, a first resistance arranged between the first input terminal of the operational amplifier and the first main terminal of the transistor, a second resistance arranged between a predetermined node and a ground line, the predetermined node being between the first input terminal of the operational amplifier and the first resistance, first to Nth transistors, each of which has a control terminal connected to the control terminal or the second main terminal of the transistor, and has a main terminal outputting a current, where N is an integer of two or larger, and first to Nth switching transistors, each of which has a main terminal, the main terminals of the first to Nth switching transistors beingType: GrantFiled: March 22, 2010Date of Patent: April 17, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Takeshi Hioka, Ryu Ogiwara, Daisaburo Takashima
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Patent number: 8156393Abstract: To provide a memory system which determines a memory state such as an exhaustion level and allows a memory to be efficiently used. The memory system includes a NAND type flash memory 1 in which data can be electrically written/erased, a nonvolatile memory 2 which counts the number of erase operations of the NAND type flash memory 1 and retains the number of erase operations and a maximum number of erase operations, and a controller 3 which has a connection interface 31 to be given a self-diagnosis command from a computer 4, and retrieves the number of erase operations and the maximum number of erase operations from the nonvolatile memory 2 based on the self-diagnosis command and outputs the number of erase operations and the maximum number of erase operations to the computer 4 through the connection interface 31.Type: GrantFiled: November 28, 2007Date of Patent: April 10, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Yasushi Nagadomi, Daisaburo Takashima, Kosuke Hatsuda, Shinichi Kanno
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Publication number: 20120069623Abstract: One embodiment provides a ferroelectric memory including: memory cells each including a ferroelectric memory; first and second bitlines configured to read out cell signals from the memory cells; a first circuit configured to fix, when the cell signal is read from the memory cell to the first bitline, a voltage of the second bitline to a first power-supply voltage, and then set the second bitline to a second power-supply voltage different from the first power-supply voltage; a second circuit configured to set, after the first circuit sets the second bitline to the second power-supply voltage, the second bitline to a reference voltage; and a third circuit configured to amplify a voltage difference between the first bitline to which the cell signal is read and the second bitline to which the reference voltage is set.Type: ApplicationFiled: September 12, 2011Publication date: March 22, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tadashi MIYAKAWA, Daisaburo Takashima
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Publication number: 20120068763Abstract: According to one embodiment, a semiconductor integrated circuit device includes an output circuit which includes an inverter having a first transistor and a second transistor whose current paths are series-connected between a first power supply voltage and a second power supply voltage, a first diode circuit one end of which is connected to the first power supply voltage, and the other end of which is connected to a control terminal of the first transistor, and an adjustment circuit which forms a current path for discharging a charge of the control terminal of the first transistor to the second power supply voltage when an input clock is at a first level.Type: ApplicationFiled: September 15, 2011Publication date: March 22, 2012Inventors: Takeshi HIOKA, Daisaburo Takashima