Patents by Inventor Toshifumi Shano
Toshifumi Shano 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: 9947408Abstract: A semiconductor memory device includes a block of memory cells including first, second, and third memory cells, a first word line electrically connected to a gate of the first memory cell, a second word line electrically connected to a gate of the second memory cell, a third word line electrically connected to a gate of the third memory cell, and a control circuit configured to access the block in one of at least first and second modes to perform an operation thereon. When the control circuit accesses the block in the first mode, the same voltage is applied to the first and second word lines throughout the operation, and when the control circuit accesses the block in the second mode, the same voltage is applied to the second and third word lines throughout the operation.Type: GrantFiled: February 26, 2016Date of Patent: April 17, 2018Assignee: Toshiba Memeory CorporationInventors: Toshifumi Shano, Masanobu Shirakawa, Tokumasa Hara
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Publication number: 20160260483Abstract: A semiconductor memory device includes a block of memory cells including first, second, and third memory cells, a first word line electrically connected to a gate of the first memory cell, a second word line electrically connected to a gate of the second memory cell, a third word line electrically connected to a gate of the third memory cell, and a control circuit configured to access the block in one of at least first and second modes to perform an operation thereon. When the control circuit accesses the block in the first mode, the same voltage is applied to the first and second word lines throughout the operation, and when the control circuit accesses the block in the second mode, the same voltage is applied to the second and third word lines throughout the operation.Type: ApplicationFiled: February 26, 2016Publication date: September 8, 2016Inventors: Toshifumi SHANO, Masanobu SHIRAKAWA, Tokumasa HARA
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Patent number: 9299438Abstract: According to one embodiment, a semiconductor memory device includes a first string; a second string; and a controller. The first string is coupled with a first bit line and includes first memory cells. The second string is coupled with a second bit line and includes second memory cells. The controller executes writing first data into the first memory cells and writing second data into the second memory cells simultaneously. The controller reads data from the first and second strings after writing the first and second data.Type: GrantFiled: September 17, 2013Date of Patent: March 29, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Tokumasa Hara, Naoya Tokiwa, Hiroshi Sukegawa, Hitoshi Iwai, Toshifumi Shano, Shirou Fujita
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Patent number: 9177661Abstract: According to one embodiment, a semiconductor memory device reads data in units of page. The device includes: a memory cell array; a plurality of latch circuits; and an arithmetic operation circuit. The memory cell array holds data multiplexed in at least three pages. The latch circuits read and hold the multiplexed data at a startup. The arithmetic operation circuit performs operations by use of the multiplexed data.Type: GrantFiled: December 27, 2013Date of Patent: November 3, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Tokumasa Hara, Naoya Tokiwa, Hiroshi Sukegawa, Hitoshi Iwai, Toshifumi Shano, Shirou Fujita
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Patent number: 9165655Abstract: A nonvolatile semiconductor memory device comprises multiple memory strings each including a plurality of first and second groups of serially connected memory cells, and a back gate transistor serially connected between the first and second groups of memory cells, a plurality of word lines, each word line being connected to a control gate of a different memory cell in each of the memory strings, a voltage generating circuit configured to generate control voltages of different voltage levels, and a control circuit configured to control application of control voltages to the word lines and the back gate line. A control voltage applied to the back gate line may be varied depending on how far a selected word line is from the back gate line, and a control voltage applied to unselected word lines may be varied depending on how far the unselected word line is from the selected word line.Type: GrantFiled: August 25, 2014Date of Patent: October 20, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Koji Hosono, Toshifumi Shano
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Publication number: 20150036434Abstract: According to one embodiment, a semiconductor memory device reads data in units of page. The device includes: a memory cell array; a plurality of latch circuits; and an arithmetic operation circuit. The memory cell array holds data multiplexed in at least three pages. The latch circuits read and hold the multiplexed data at a startup. The arithmetic operation circuit performs operations by use of the multiplexed data.Type: ApplicationFiled: December 27, 2013Publication date: February 5, 2015Applicant: Kabushiki Kaisha ToshibaInventors: Tokumasa HARA, Naoya Tokiwa, Hiroshi Sukegawa, Hitoshi Iwai, Toshifumi Shano, Shirou Fujita
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Publication number: 20150016190Abstract: A nonvolatile semiconductor memory device comprises multiple memory strings each including a plurality of first and second groups of serially connected memory cells, and a back gate transistor serially connected between the first and second groups of memory cells, a plurality of word lines, each word line being connected to a control gate of a different memory cell in each of the memory strings, a voltage generating circuit configured to generate control voltages of different voltage levels, and a control circuit configured to control application of control voltages to the word lines and the back gate line. A control voltage applied to the back gate line may be varied depending on how far a selected word line is from the back gate line, and a control voltage applied to unselected word lines may be varied depending on how far the unselected word line is from the selected word line.Type: ApplicationFiled: August 25, 2014Publication date: January 15, 2015Inventors: Koji HOSONO, Toshifumi SHANO
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Publication number: 20140369127Abstract: According to one embodiment, a semiconductor memory device includes a first string; a second string; and a controller. The first string is coupled with a first bit line and includes first memory cells. The second string is coupled with a second bit line and includes second memory cells. The controller executes writing first data into the first memory cells and writing second data into the second memory cells simultaneously. The controller reads data from the first and second strings after writing the first and second data.Type: ApplicationFiled: September 17, 2013Publication date: December 18, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Tokumasa HARA, Naoya Tokiwa, Hiroshi Sukegawa, Hitoshi Iwai, Toshifumi Shano, Shirou Fujita
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Patent number: 8854896Abstract: A nonvolatile semiconductor memory device comprises multiple memory strings each including a plurality of first and second groups of serially connected memory cells, and a back gate transistor serially connected between the first and second groups of memory cells, a plurality of word lines, each word line being connected to a control gate of a different memory cell in each of the memory strings, a voltage generating circuit configured to generate control voltages of different voltage levels, and a control circuit configured to control application of control voltages to the word lines and the back gate line. A control voltage applied to the back gate line may be varied depending on how far a selected word line is from the back gate line, and a control voltage applied to unselected word lines may be varied depending on how far the unselected word line is from the selected word line.Type: GrantFiled: March 5, 2013Date of Patent: October 7, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Koji Hosono, Toshifumi Shano
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Publication number: 20140098612Abstract: A nonvolatile semiconductor memory device comprises multiple memory strings each including a plurality of first and second groups of serially connected memory cells, and a back gate transistor serially connected between the first and second groups of memory cells, a plurality of word lines, each word line being connected to a control gate of a different memory cell in each of the memory strings, a voltage generating circuit configured to generate control voltages of different voltage levels, and a control circuit configured to control application of control voltages to the word lines and the back gate line. A control voltage applied to the back gate line may be varied depending on how far a selected word line is from the back gate line, and a control voltage applied to unselected word lines may be varied depending on how far the unselected word line is from the selected word line.Type: ApplicationFiled: March 5, 2013Publication date: April 10, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Koji HOSONO, Toshifumi SHANO
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Patent number: 7613048Abstract: A nonvolatile semiconductor memory device including a memory cell array including a plurality of electrically rewritable nonvolatile memory cells arranged in series, the memory cell storing data using a plurality of threshold levels, a threshold level storage section storing a programming method switch threshold level on which a first programming method and a second programming method are switched, a comparison circuit comparing the programming method switch threshold level with a programming data threshold level and outputting a comparison result, a control signal generation circuit setting the first programming method or the second programming method based on the comparison result and outputting a control signal corresponding to the first programming method or the second programming method and a voltage generation circuit generating a programming voltage and an intermediate voltage which are applied to the memory cell based on the control signal.Type: GrantFiled: November 2, 2007Date of Patent: November 3, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Atsushi Inoue, Toshifumi Shano
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Publication number: 20080106946Abstract: A nonvolatile semiconductor memory device including a memory cell array including a plurality of electrically rewritable nonvolatile memory cells arranged in series, the memory cell storing data using a plurality of threshold levels, a threshold level storage section storing a programming method switch threshold level on which a first programming method and a second programming method are switched, a comparison circuit comparing the programming method switch threshold level with a programming data threshold level and outputting a comparison result, a control signal generation circuit setting the first programming method or the second programming method based on the comparison result and outputting a control signal corresponding to the first programming method or the second programming method and a voltage generation circuit generating a programming voltage and an intermediate voltage which are applied to the memory cell based on the control signal.Type: ApplicationFiled: November 2, 2007Publication date: May 8, 2008Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Atsushi INOUE, Toshifumi Shano