Method and apparatus for developing multiprocessor cache control protocols using atomic probe commands and system data control response commands

A computing apparatus connectable to a cache and a memory, includes a system port configured to receive an atomic probe command or a system data control response command having an address part identifying data stored in the cache which is associated with data stored in the memory and a next coherence state part indicating a next state of the data in the cache. The computing apparatus further includes an execution unit configured to execute the command to change the state of the data stored in the cache according to the next coherence state part of the command (Full Patent Here).