| 摘要 |
PURPOSE:To eliminate a waste of input/output ports, by providing a bus controller which discriminates a control system on a basis of service requests, which are applied from plural input/output devices divided into groups, to control a high-speed bus. CONSTITUTION:A service request signal R31 applied to a request accepting part 21 from an input/output device in a block 31 is applied to a control system selecting circuit 22 through the request accepting part 21. Since the signal R31 is issued from the block 31, the circuit 22 transmits information indicating the first control system to a bus controlling part 23. As the result, the controlling part 23 controls a high-speed bus 40 in the first control system to execute the service for the input/output device in the block 31. When a service request signal R34 is outputted from an input/output device in a block 34, the circuit 22 sends information indicating the second control system to the controlling part 23, and the controlling part 23 controls the bus 40 in the second control system to execute the service for the input/output device in the block 34. Using this system, preparation of two-fold input/output ports is made unnecessary. |
