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:
Aug. 10, 2004
Filed:
May. 08, 2002
Steven D. Krueger, Dallas, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A method and apparatus is provided for operating a digital system having several processors ( ) and peripheral devices ( ) connected to a shared memory subsystem ( ). Two or more of the processors execute separate operating systems. In order to control access to shared resources, a set of address space regions within an address space of the memory subsystem is defined within system protection map (SPM) ( ). Resource access rights are assigned to at least a portion of the set of regions to indicate which initiator resource is allowed to access each region. Using the address provided with the access request, the region being accessed by a memory access request is identified by the SPM. During each access request, the SPM identifies the source of the request using a resource identification value (R-ID) provided with each access request and then a determination is made of whether the resource accessing the identified region has access rights for the identified region. Access to the identified region is allowed to an initiator resource only if the resource has access rights to the identified region, otherwise an error process is initiated ( ).