Patents by Inventor Yasushi Kasa

Yasushi Kasa 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: 20160259583
    Abstract: The present invention has an object of providing a storage device capable of making recovery of erased data difficult and erasing the data safely. Provided is a storage device system including a driver controlling an interface between a nonvolatile memory and an external host; and a second controller located between the nonvolatile memory and a first controller, the second controller detecting a logical address of an old data area for a deleted or overwritten file, the second controller detecting a logical address of an old data area for a deleted or overwritten file. The second controller writes invalid data to the logical address of the old data area for the deleted or overwritten file.
    Type: Application
    Filed: June 5, 2015
    Publication date: September 8, 2016
    Inventors: Yasushi KASA, Moriyoshi NAKASHIMA
  • Publication number: 20140281581
    Abstract: A storage device includes a storage area and connected to a computer for causing a file system to operate. The file system causes a data area for storing contents of a plurality of files and a management area for managing the plurality of files to be secured in the storage area. The storage device includes the storage area; a file system monitor for detecting that the file system has performed an operation of erasing a file; and a controller for, when the file system monitor detects an operation of erasing the file, performing erasure or write to put an area corresponding to the erased file in the storage area into an unrecoverable state.
    Type: Application
    Filed: March 17, 2014
    Publication date: September 18, 2014
    Applicant: GENUSION, INC.
    Inventor: Yasushi KASA
  • Patent number: 8769377
    Abstract: Error correcting systems, methods, and devices for non-volatile memory are disclosed. In one embodiment, a non-volatile memory device comprises a data area for storing data, an error correcting code generation section for generating an error correcting code in response to receipt of a code generation command, and an error correcting code area for storing the error correcting code.
    Type: Grant
    Filed: May 3, 2013
    Date of Patent: July 1, 2014
    Assignee: Spansion LLC
    Inventor: Yasushi Kasa
  • Publication number: 20130268823
    Abstract: Error correcting systems, methods, and devices for non-volatile memory are disclosed. In one embodiment, a non-volatile memory device comprises a data area for storing data, an error correcting code generation section for generating an error correcting code in response to receipt of a code generation command, and an error correcting code area for storing the error correcting code.
    Type: Application
    Filed: May 3, 2013
    Publication date: October 10, 2013
    Inventor: Yasushi KASA
  • Patent number: 8438460
    Abstract: Error correcting systems, methods, and devices for non-volatile memory are disclosed. In one embodiment, a non-volatile memory device comprises a data area for storing data, an error correcting code generation section for generating an error correcting code in response to receipt of a code generation command, and an error correcting code area for storing the error correcting code.
    Type: Grant
    Filed: June 22, 2012
    Date of Patent: May 7, 2013
    Assignee: Spansion LLC
    Inventor: Yasushi Kasa
  • Publication number: 20120266047
    Abstract: Error correcting systems, methods, and devices for non-volatile memory are disclosed. In one embodiment, a non-volatile memory device comprises a data area for storing data, an error correcting code generation section for generating an error correcting code in response to receipt of a code generation command, and an error correcting code area for storing the error correcting code.
    Type: Application
    Filed: June 22, 2012
    Publication date: October 18, 2012
    Inventor: Yasushi KASA
  • Patent number: 8225172
    Abstract: Error correcting systems, methods, and devices for non-volatile memory are disclosed. In one embodiment, a non-volatile memory device comprises a data area for storing data, an error correcting code generation section for generating an error correcting code in response to receipt of a code generation command, and an error correcting code area for storing the error correcting code. The non-volatile memory device further comprises a detector circuit for detecting the generating of the error correcting code, and a read section for correcting the data stored in the data area based on the error correcting code upon the detecting of the generation of the error correcting code by the detector circuit, where the code generation command is forwarded by a memory controller when the data are is filled with the data beyond a threshold level.
    Type: Grant
    Filed: June 16, 2008
    Date of Patent: July 17, 2012
    Assignee: Spansion LLC
    Inventor: Yasushi Kasa
  • Patent number: 7679150
    Abstract: A semiconductor device is provided which includes a pair of metal interconnections (B, C) provided above a semiconductor substrate (10), a program layer (20) provided over the pair of metal interconnections (B, C) and in which an opening (21) may be selectively formed in the program layer (20) on the basis of programming information, and a read circuit (40) reading the programming information by determining whether such an opening (21) is formed in the program layer (20) by utilizing an electrostatic capacitance between the pair of metal interconnections (B, C). The program layer (20) may be made of a material having a dielectric constant higher than that of air or the program layer (20) may be made of a conductor or a material having a dielectric constant lower than that of air.
    Type: Grant
    Filed: April 27, 2006
    Date of Patent: March 16, 2010
    Assignee: Spansion LLC
    Inventor: Yasushi Kasa
  • Publication number: 20090158123
    Abstract: Error correcting systems, methods, and devices for non-volatile memory are disclosed. In one embodiment, a non-volatile memory device comprises a data area for storing data, an error correcting code generation section for generating an error correcting code in response to receipt of a code generation command, and an error correcting code area for storing the error correcting code.
    Type: Application
    Filed: June 16, 2008
    Publication date: June 18, 2009
    Inventor: Yasushi KASA
  • Patent number: 7206241
    Abstract: The semiconductor device of the present invention includes at least one dummy cell of a programmed state proximately located to an edge of a reference cell array. Thus, the leak current does not flow when a data of the cell on the edge of the reference cell array is read out. The memory cell located around the center of the reference cell array has neighboring cells of the programmed state, and the leak current can be prevented when the data is read out from all the reference cells. Thus, the reference current can be supplied stably.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: April 17, 2007
    Assignee: Spansion LLC
    Inventors: Kazunari Kido, Yasushi Kasa, Minoru Yamashita, Kazuhiro Kurihara, Hiroaki Wada
  • Publication number: 20070052064
    Abstract: A semiconductor device is provided which includes a pair of metal interconnections (B, C) provided above a semiconductor substrate (10), a program layer (20) provided over the pair of metal interconnections (B, C) and in which an opening (21) may be selectively formed in the program layer (20) on the basis of programming information, and a read circuit (40) reading the programming information by determining whether such an opening (21) is formed in the program layer (20) by utilizing an electrostatic capacitance between the pair of metal interconnections (B, C). The program layer (20) may be made of a material having a dielectric constant higher than that of air or the program layer (20) may be made of a conductor or a material having a dielectric constant lower than that of air.
    Type: Application
    Filed: April 27, 2006
    Publication date: March 8, 2007
    Inventor: Yasushi Kasa
  • Patent number: 7012838
    Abstract: A nonvolatile semiconductor memory device includes a plurality of blocks each having a nonvolatile memory cell array, and a program potential generating circuit which supplies a program potential to the nonvolatile memory cell array, wherein the program potential generating circuit adjusts the program potential according to a first address signal selecting one of the blocks and a second address signal indicating a position of a write-accessed memory cell in the noted one of the blocks.
    Type: Grant
    Filed: August 1, 2003
    Date of Patent: March 14, 2006
    Assignee: Fujitsu Limited
    Inventors: Yasushi Kasa, Jyoji Kato
  • Publication number: 20050276112
    Abstract: The semiconductor device of the present invention includes at least one dummy cell of a programmed state proximately located to an edge of a reference cell array. Thus, the leak current does not flow when a data of the cell on the edge of the reference cell array is read out. The memory cell located around the center of the reference cell array has neighboring cells of the programmed state, and the leak current can be prevented when the data is read out from all the reference cells. Thus, the reference current can be supplied stably.
    Type: Application
    Filed: May 11, 2005
    Publication date: December 15, 2005
    Inventors: Kazunari Kido, Yasushi Kasa, Minoru Yamashita, Kazuhiro Kurihara, Hiroaki Wada
  • Patent number: 6865133
    Abstract: A memory circuit has a plurality of blocks which further comprises a plurality of regular sectors and a spare sector, wherein each sector further comprises a plurality of memory cells, and when a regular sector in a first block is defective, this defective regular sector is replaced with a spare sector in a second block. And responding to an address to be supplied, the regular sector corresponding to the supplied address in the first block and the spare selector in the second block are selected simultaneously during a first period, and after the first period, selection of one of the regular sector and the spare sector is maintained according to the result of redundancy judgment on whether the supply address matches with the redundant address.
    Type: Grant
    Filed: September 2, 2003
    Date of Patent: March 8, 2005
    Assignee: Fujitsu Limited
    Inventors: Yoshihiro Tsukidate, Kazuhiro Kurihara, Yasushi Kasa, Tsutomu Nakai, Andy Cheung
  • Publication number: 20040109371
    Abstract: A memory circuit has a plurality of blocks which further comprises a plurality of regular sectors and a spare sector, wherein each sector further comprises a plurality of memory cells, and when a regular sector in a first block is defective, this defective regular sector is replaced with a spare sector in a second block. And responding to an address to be supplied, the regular sector corresponding to the supplied address in the first block and the spare selector in the second block are selected simultaneously during a first period, and after the first period, selection of one of the regular sector and the spare sector is maintained according to the result of redundancy judgment on whether the supply address matches with the redundant address.
    Type: Application
    Filed: September 2, 2003
    Publication date: June 10, 2004
    Inventors: Yoshihiro Tsukidate, Kazuhiro Kurihara, Yasushi Kasa, Tsutomu Nakai, Andy Cheung
  • Publication number: 20040062078
    Abstract: A nonvolatile semiconductor memory device includes a plurality of blocks each having a nonvolatile memory cell array, and a program potential generating circuit which supplies a program potential to the nonvolatile memory cell array, wherein the program potential generating circuit adjusts the program potential according to a first address signal selecting one of the blocks and a second address signal indicating a position of a write-accessed memory cell in the noted one of the blocks.
    Type: Application
    Filed: August 1, 2003
    Publication date: April 1, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Yasushi Kasa, Jyoji Kato
  • Patent number: 6662262
    Abstract: A simultaneous operation flash memory capable of providing double protection to An OTP sector. The preferred simultaneous operation flash memory comprises an OTP write-protect CAM, which is in a programmed state if the OTP sector is write-protected. In addition, the preferred simultaneous flash memory further includes an OTP sector lock CAM that is electrically connected with the OTP write-protect CAM. The OTP sector lock CAM is used to lock the OTP write-protect CAM in the programmed state, which, in turn, will designate the OTP sector as read only.
    Type: Grant
    Filed: October 19, 1999
    Date of Patent: December 9, 2003
    Assignees: Advanced Micro Devices, Inc., Fujitsu Limited
    Inventors: Yasushi Kasa, Johnny Chung-Lee Chen, Guowei Wang, Tiao-Hua Kuo
  • Patent number: 6646920
    Abstract: A semiconductor memory device includes a plurality of word lines and a plurality of bit lines. A plurality of memory cells, each formed of a MIS transistor, are disposed at intersections of the word lines and the bit lines. The threshold voltages of the MIS transistors being externally electrically controllable according to charges to be injected to floating gates thereof. The floating gates of the MIS transistors being simultaneously discharged to collectively erase the memory cells. A first row decoder applies a normal voltage to a selected word line to select memory cells connected to the selected word line, when reading data. A second row decoder applies a predetermined source voltage to sources of memory cells connected to the selected word line, and applies an unselected state establishing voltage to the sources of memory cells, including those overerased by the collective erasing, connected to unselected word lines, when reading data.
    Type: Grant
    Filed: October 7, 2002
    Date of Patent: November 11, 2003
    Assignee: Fujitsu Limited
    Inventors: Nobuaki Takashina, Yasushi Kasa, Kiyoshi Itano
  • Publication number: 20030198083
    Abstract: A semiconductor memory device has 2n word lines, a plurality of bit lines, a plurality of nonvolatile memory cells disposed at each intersection of the word lines and the bit lines, a write circuit for writing data to a memory cell located at an intersection of selected ones of the word lines and the bit lines, and a sense amplifier for reading data out of the memory cells. Further, the semiconductor memory device comprises a first unit for simultaneously selecting a block of 2m (n>m) word lines among the 2n word lines, and a second unit for not selecting a block of 2k (m>k) word lines among the 2m word lines. The second unit does not select the block of 2k word lines, and selects a block of 2k word lines prepared outside the 2n word lines when any one of the 2k word lines among the 2m word lines is defective. Consequently, redundant word lines are effectively employed, write and verify operations are stable, and thereby the yield and performance of the semiconductor memory device are improved.
    Type: Application
    Filed: November 26, 2002
    Publication date: October 23, 2003
    Applicant: Fujitsu Limited
    Inventors: Takao Akaogi, Nobuaki Takashina, Yasushi Kasa, Kiyoshi Itano, Hiromi Kawashima, Minoru Yamashita, Shouichi Kawamura
  • Patent number: 6633949
    Abstract: A bank selector encoder comprises a partition indicator circuit having a plurality of partition boundary indicator terminals, a plurality of inverters arranged in a plurality of columns, with each column of the inverters coupled to a respective one of a plurality of columns of ROM cells in a ROM array and a plurality of bank selector code outputs coupled to respective columns of the inverters. The partition boundary indicator terminals are capable of designating a memory partition boundary to identify an upper memory bank and a lower memory bank. The bank selector encoder is capable of generating an identifying bank selector code for each of a plurality of the predetermined memory partition boundaries. The bank selector encoder outputs code bits of a bank selector code based upon the partition boundary indicator terminals.
    Type: Grant
    Filed: June 26, 2001
    Date of Patent: October 14, 2003
    Assignees: Advanced Micro Devices, Inc., Fujitsu Limited
    Inventors: Tiao-Hua Kuo, Yasushi Kasa, Nancy Leong, Johnny Chen, Michael Van Buskirk