The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 03, 1996
Filed:
Oct. 24, 1994
Keishichiro Tanaka, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A control system controls a disk unit and a cache storage unit having a cache memory and a nonvolatile memory based on a writing instruction supplied from a host computer. The control system includes a first processing block for writing the updated data in both the cache memory and the nonvolatile memory when an unused area in the nonvolatile memory is not less than a reference area. The updated data which has been written in the nonvolatile memory is written in the disk unit asynchronously with the writing instruction. The control system further includes a second processing block for writing the updated data in both the cache memory and the disk unit when the unused area in the nonvolatile memory is less than the reference area and the nonvolatile memory does not have the data corresponding to the identified track. The control system also includes a third processing block for carrying out the same process as that carried out by the first processing block when the unused area in the nonvolatile memory can be used for storing the data for one track. In addition, the control system includes a fourth processing block for writing the data which has been stored in the nonvolatile memory in the disk unit, and for writing the updated data in both the cache memory and the disk unit when the unused area in the nonvolatile memory cannot be used for storing the data for one track.