| 摘要 |
PURPOSE:To perform or invalidate processing according to an execution permit command or inhibition command by sending the execution permit command or execution inhibition command from a command-transmission-side subsystem and by holding the execution of the command when the received command changes in state at a reception-side subsystem. CONSTITUTION:Subsystems 1-0-1-n are connected by single bus 2, and then provided with coupled processor 6 connected to bus control circuit 3, sequence control circuit 4, and data transmission/reception control circuit 5. Further, computer 8 is connected to processor 6 via bus 7 in the subsystem. To circuits 3 of respective systems 1-0-1-n, hold line HLD and request address lines RQA0 and RQAn are connected and to circuits 4, command response control line CRA is connected. Further, data line DSL is connected to circuit 5. From a transmission-side subsystem, an execution permit command or execution inhibition command is sent and at a reception-side subsystem, the execution or invalidation of the processing is determined according to the sent command. |
