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. 06, 1999
Filed:
Jun. 27, 1997
Bruce Petrick, Sunnyvale, CA (US);
Dale Greenley, Los Gatos, CA (US);
Sun Microsystems, Inc., Palo Alto, CA (US);
Abstract
An apparatus for processing a write miss signal from a copy-back data cache includes a load-store unit with an allocating load buffer, a non-allocating store buffer, and a priority control circuit to generate write-after-read hazards and read-after-write hazards to preserve the processing priority of entries within the allocating load buffer and the non-allocating store buffer. A prefetch circuit enqueues a prefetch command in the allocating load buffer and a store command in the non-allocating store buffer upon a write miss to the copy-back data cache. Thus, the priority control circuit forces a write-after-read hazard on the store command in the non-allocating store buffer. As a result, the prefetch command in the allocating load buffer secures an allocated line in the copy-back data cache, allowing the store command of the non-allocating store buffer to write data to the allocated line.