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:
Feb. 15, 1994
Filed:
May. 04, 1992
Applicant:
Inventor:
Fong-Lu Lin, San Jose, CA (US);
Assignee:
OPTi, Inc., Santa Clara, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ; G06F / ;
U.S. Cl.
CPC ...
395425 ; 364D / ; 36424341 ; 395400 ;
Abstract
According to the invention, a chipset is provided which powers up in a default state with cacheing disabled and which writes permanently non-cacheable tags into tag RAM entries corresponding to memory addresses being read while cacheing is disabled. Even though no 'valid' bit is cleared, erroneous cache hits after cacheing is enabled are automatically prevented since any address which does match a tag in the tag RAM, is a non-cacheable address and will force retrieval directly from main memory anyway. Two cache tag test modes are also described, as is a cache sizing algorithm.