US Patent 7103528 Emulated atomic instruction sequences in a multiprocessor system

A method for enabling access to a resource shared by at least two processors over a bus that supports an atomic instruction, wherein a first processor does not support the atomic instruction, the method comprising the steps of providing an atomic instruction emulator coupled to the bus, the atomic instruction emulator including at least two register sets for implementing an atomic instruction; receiving by the emulator over the bus an emulation request from the first processor to perform the atomic instruction on the shared resource, the request including an address location; and performing by the emulator the atomic instruction for the processor using the data and the address location from the request.