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. 14, 1995
Filed:
Sep. 15, 1992
Steven E Golson, Carlisle, MA (US);
Sun Microsystems, Inc., Mountain View, CA (US);
Abstract
A computer system consisting of a host processor, memory and peripheral devices coupled via a bus which provides emulation of a microprocessor by coupling the microprocessor to the bus. The host processor provides emulation of microprocessor peripherals such that a microprocessor based system is supported and executes processes. A takeover mechanism is provided to enable the host processor to temporarily takeover the microprocessor to perform certain tasks. The host processor causes an interrupt to occur in the microprocessor and monitors the bus cycles initiated by the microprocessor to determine when the microprocessor performs fetches of the routine to service the interrupt. The host processor intercepts fetches for information regarding the location of the interrupt service routine and provides information that causes the microprocessor to execute code of a process to be executed during the takeover. For example, during the takeover, noninvasive debugging of the microprocessor can be performed. Alternatively, a context switch of processes can be performed during the takeover whereby the microprocessor will continue processing in the context of the process stored in the microprocessor. Once the takeover is complete, the host processor places the microprocessor in a state for normal processing after which normal processing by the microprocessor continues.