| 摘要 |
PURPOSE:To decrease the number of signal lines by providing a reserve bit part in response to each channel device to store the information on the using state of the channel device and replacing the contents of said reserve bit part to secure the right of priority for application of channel devices. CONSTITUTION:A reserve bit means 13 is set in a channel processor 11 in response to each channel device 12. The device 12 can replace the reserve bit via a bus line and the processor 11 can replace directly the reserve bit. Then the processor 11 or the device 12 replaces the reserve bit before a start or interruption process to acquire the processing priority. If the device fails to acquire the priority, the state or interruption process is discontinued. Thus it is possible to decrease extremely the number of signal lines set between the processor 11 and the device 12. |
