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:
Nov. 18, 2003
Filed:
Mar. 30, 2001
David A. Courtright, Los Gatos, CA (US);
Lawrence H. Hudepohl, Saratoga, CA (US);
Kevin D. Kissell, Le Bar sur Loup, FR;
G. Michael Uhler, Menlo Park, CA (US);
MIPS Technologies, Inc., MountainView, CA (US);
Abstract
An apparatus and method are provided that enable a central processing unit (CPU) to extend the attributes of virtual memory beyond that which an existing translation lookaside buffer within the CPU is capable of storing while at the same time preserving compatibility with legacy operating system software. The apparatus includes a translation lookaside buffer and extended attributes logic. The translation lookaside buffer (TLB) stores a plurality of TLB entries. Each of the TLB entries has an extended memory attributes index field. The extended attributes logic is coupled to the TLB. The extended attributes logic employs the extended memory attributes index field to access one of a plurality of extended memory attributes registers that is external to the TLB. Contents of the extended memory attributes register prescribe specific extended properties for a corresponding virtual memory page. The extended memory attributes index field is a field that is also employed by a legacy memory management protocol to prescribe legacy properties. The plurality of extended attributes registers are initialized to states that correspond to the legacy properties so that the CPU is compatible with operating systems employing the legacy memory management protocol.