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:
May. 27, 1997
Filed:
Jul. 02, 1996
Applicant:
Inventor:
Richard D Freeman, Mission Viejo, CA (US);
Assignee:
Unisys Corporation, Blue Bell, PA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ; G06F / ;
U.S. Cl.
CPC ...
395445 ; 364D / ; 364D / ; 3642434 ; 36424342 ; 395450 ;
Abstract
A microcode cache memory is provided on a processor chip for supplying frequently used microcode instruction words to a processor. A bank of multiple Tag-Status RAMs holds addresses of microcode words residing in a bank of Data RAMs. A state machine and a special Least Recently Used Random Access Memory (LRU RAM) operate to maintain the more frequently used words in the Data RAMs so that more hits occur to provide the requested word in one clock cycle. A 90 bit microcode word with 20 fields enables the processor to perform multiple functions simultaneously in parallel.