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:
Mar. 27, 1990
Filed:
Mar. 15, 1988
Claudio Fiacconi, Arcore, IT;
Bull HN Information Systems Italia S.p.A., Caluso, IT;
Abstract
A cache memory when receiving an operand read request and the operand address from a central processing unit responds with a signal indicative of an operand being available in the cache memory before having checked if such operand is effectively in the cache or if in a previous operand request, the effective operand presence in the cache had occurred or started a memory read operation before having checked if such operand is effectively not present in the cache or if in a previous operand request, the effective absence of the operand from the cache has occurred. The decision among the two alternatives is determined by state logic which stores the previously occurred HIT condition denoting the requested operand presence in the cache or MISS condition denoting the requested operand absence from the cache memory. The states of these conditions are updated during the course of a current read operation if a predicted HIT condition is followed by an effective MISS condition or if a predicted MISS condition is followed by an effective HIT condition.