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:
Jul. 16, 1985
Filed:
Mar. 03, 1982
James R Hamstra, Plymouth, MN (US);
Merlin L Hanson, Arden Hills, MN (US);
Sperry Corporation, New York, NY (US);
Abstract
In a hierarchical memory system, replacement of segments in a cache memory is governed by a least recently used algorithm, while trickling of segments from the cache memory to the bulk memory is governed by the age since first write. The host processor passes an AGEOLD parameter to the memory subsystem and this parameter regulates the trickling of segments. Unless the memory system is idle (no I/O activity), no trickling takes place until the age of the oldest written-to segment is at least as great as AGEOLD. A command is generated for each segment to be trickled and the priority of execution assigned to such commands is variable and determined by the relationship of AGEOLD to the oldest age since first write of any of the segments. If the subsystem receives no command from the host processor for a predetermined interval, AGEOLD is ignored and any written-to segment becomes a candidate for trickling.