MULTIPROCESSOR SYSTEM INCLUDING AN EXCLUSIVE ACCESS CONTROLLER WITH LOCK REQUEST HOLDING AND GRANT CIRCUITS

An exclusive access controller is incorporated into a multiprocessor system in which each processor generates a lock request and subsequently a memory access request when accessing shared data stored in the main memory of the system. Lock requests from the processors are held in a lock request holding circuit and one of the lock requests is selected by lock request arbitration circuitry and stored in a lock request grant circuit. Each processor includes a memory access inhibit circuit that inhibits the process from generating a memory access request until its lock request is stored in the lock request grant circuit.