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:
Jan. 31, 1995
Filed:
Nov. 27, 1991
Kazumasa Hamaguchi, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A block substitution method of a cache memory incudes the steps of storing data integrity information with a main memory for each block of the cache memory and calculating a non-reference period of each block. The non-reference periods of the blocks are compared to determine an order of the blocks based on the non-reference periods and a difference between the non-reference period of the block having a longest non-reference period and the non-reference period of other blocks is calculated. Data integrity in the block having the longest non-reference period is examined and when there is no data integrity in that block the data integrity in other blocks is examined in the order of the non-reference period. A block having a longest non-reference period among the blocks having the data integrity is determined and the determined block is selected as a block to be substituted by a new data block when the difference is smaller than a predetermined value. New data is loaded to the selected block.