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:
Dec. 21, 2010
Filed:
Mar. 17, 2005
Ray A. Bittner, Jr., Redmond, WA (US);
Michael Ginsberg, Redmond, WA (US);
Ray A. Bittner, Jr., Redmond, WA (US);
Michael Ginsberg, Redmond, WA (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
A multi-tasking operating system and method updates PCI address values in an extension register to ensure that various threads utilize the correct values when accessing peripheral PCI devices. When application program threads require access to a PCI device, the operating system writes the high order bits of the PCI device address to two places: (1) the extension register of the PCI host bridge to allow immediate addressing of the PCI device, and (2) separate memory locations associated with the threads. When a context switch occurs from a first thread to a second thread, the operating system retrieves the stored value from the memory location associated with the second thread and writes the value to the extension register. In this manner, when the second thread requires access to its PCI device, the proper address value is already located in the extension register.