The 1st agent informs about the necessity of service to the 2nd agent in the bus which transfers the data between the multiple data processing agents, the manner

摘要

PURPOSE: To improve the performance of a method for supporting the service request of bus architecture by using the arbitration number of the destination as a source and immediately starting a requested service routine after it is recognized that the ownership of a bus is immediately permitted at the destination. CONSTITUTION: Concerning the bus with which data are transferred between plural data processing agents by providing an arbitration line 34, address and data line 36 and control line 35, when the source request a service, that source requests the arbitration number of the destination. Even when the destination does not arbitrates the bus itself later, the ownership of the bus is given to that destination, afterwards, that destination immediately assumes the execution of the request and then, the requested service routine is started. Thus, standby time for destination request is made almost the same with the standby time of bus architecture to use an individual request line, and the performance of service request support can be improved.