Patent ID: 6529933
Filing Date: 2003-03-04
Classification: G06F

Abstract:
A data processing system for arbitrating between exclusive requests for a resource comprising:a device for sending requests to lock and unlock the resource, wherein each request is an instruction; an addressable memory for storing variables; a bus for coupling said device to said memory; a variable associated with the resource, wherein the variable is stored in the memory at an address and the variable indicates whether the resource is locked; and lock management means for locking and unlocking the resource by changing the variable in response to requests from the device to a single bus operation carried out in response to a single instruction wherein one of said requests is transferred on said bus to thereby avoid multiple bus operations to change the variable wherein the lock instruction contains solely a test and set lock operation code and the address of the variable and the unlock instruction contains solely a clear and invalidate operation code and the address of the variable.