Patents by Inventor Shigeo Homma

Shigeo Homma 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).

  • Cache control method and apparatus
    Patent number: 6085286
    Abstract: In an information processing system having a data processing apparatus, a control unit for a cache memory, and a storage unit for storing a record, respectively interconnected together, wherein when the control unit receives from the data processing apparatus a write request for a record to be written and if the record to be written is not being stored in the cache memory, the control unit receives a data to be written in the object record from the data processing apparatus and stores the received data in the cache memory. After notifying the data processing apparatus of a completion of a data write process, the control unit checks if the object record in which the data stored in the cache memory is being stored in the storage unit, if the object record is being stored in the storage unit, the data in the cache memory is written in the storage unit, and if not, the data in the cache memory is not written and such effect is notified to the data processing apparatus.
    Type: Grant
    Filed: December 21, 1998
    Date of Patent: July 4, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Akira Yamamoto, Shigeo Homma, Yoshihiro Asaka, Yoshiaki Kuwahara, Akira Kurano, Masafumi Nozawa, Hiroyuki Kitajima
  • Cache control by adding record identification information to partial write request
    Patent number: 5694576
    Abstract: In an information processing system having a data processing apparatus, a control unit for a cache memory, and a storage unit for storing a record, respectively interconnected together, wherein when the control unit receives from the data processing apparatus a write request for a record to be written and if the record to be written is not being stored in the cache memory, the control unit receives a data to be written in the object record from the data processing apparatus and stores the received data in the cache memory. After notifying the data processing apparatus of a completion of a data write process, the control unit checks if the object record in which the data stored in the cache memory is being stored in the storage unit, if the object record is being stored in the storage unit, the data in the cache memory is written in the storage unit, and if not, the data in the cache memory is not written and such effect is notified to the data processing apparatus.
    Type: Grant
    Filed: September 19, 1995
    Date of Patent: December 2, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Akira Yamamoto, Shigeo Homma, Yoshihiro Asaka, Yoshiaki Kuwahara, Akira Kurano, Masafumi Nozawa, Hiroyuki Kitajima
  • Cache control method and apparatus for storing data in a cache memory and for indicating completion of a write request irrespective of whether a record to be accessed exists in an external storage unit
    Patent number: 5497472
    Abstract: In an information processing system having a data processing apparatus, a control unit for a cache memory, and a storage unit for storing a record, respectively interconnected together, wherein when the control unit receives from the data processing apparatus a write request for a record to be written and if the record to be written is not being stored in the cache memory, the control unit receives a data to be written in the object record from the data processing apparatus and stores the received data in the cache memory. After notifying the data processing apparatus of a completion of a data write process, the control unit checks if the object record in which the data stored in the cache memory is being stored in the storage unit, if the object record is being stored in the storage unit, the data in the cache memory is written in the storage unit, and if not, the data in the cache memory is not written and such effect is notified to the data processing apparatus.
    Type: Grant
    Filed: January 19, 1995
    Date of Patent: March 5, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Akira Yamamoto, Shigeo Homma, Yoshihiro Asaka, Yoshiaki Kuwahara, Akira Kurano, Masafumi Nozawa, Hiroyuki Kitajima
  • Method of fault handling for a disk control unit with built-in cache
    Patent number: 5390186
    Abstract: In order for a disk control unit with built-in cache to write non-reflective data in the cache to a disk drive without stopping extension of a read/write command from host computer in the event of a fault in the cache or its backup memory, the track data in normal one of the cache and its backup memory is written to a certain physical track of the disk drive upon judging at read/write command execution that the accessed track is a non-reflective track, and a read/write command from the host computer is implemented for the physical track of the disk drive which has completed the non-reflective track write operation.
    Type: Grant
    Filed: November 20, 1990
    Date of Patent: February 14, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Tomohiro Murata, Masaharu Akatsu, Kenzo Kurihara, Shigeo Homma, Akira Yamamoto