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:
Oct. 18, 1991
Samir Mitra, Milpitas, CA (US);
Renukanthan Raman, Sunnyvale, CA (US);
Joseph Petollno, Palo Alto, CA (US);
Sun Microsystems, Inc., Mountain View, CA (US);
Abstract
A cache memory controller and an associated method for fetching data are utilized to reduce the idle time of a central processing unit (CPU) of a computer system. Control circuitry and a plurality of cache fill status registers are provided to a cache controller to enable a data word to be fetched and returned to the CPU while a cache memory fill initiated due to a prior cache miss is still in progress. The data word is returned if the data word is stored in a main memory location which corresponds to a memory block offset of a main memory block frame currently being mapped into the cache memory. The data word is retrieved and returned to the CPU simultaneous with its writing into the cache memory, if the data word has not been written into the cache memory; otherwise, the data word is retrieved and returned to the CPU at the next dead cycle. As a result, CPU idle time due to cache read misses is reduced.