| 摘要 |
PURPOSE:To increase the processing speed of IO control and to shorten initialization time by providing a stand-by area for control words for controlling input and output equipment in a data channel device, and referring to a control word reference table and judging whether access to stand-by area is effective or not. CONSTITUTION:When a clear instruction for a data channel device arrives at a line S2 from a central controller CC, a microprogram execution processing part muPCTL judges initialization to sends a system setting signal to input and output equipment IO. Then, blank display of a state ''1'' is performed and in a stand-by area control table TBL, all-''1'' data is written through an adder ADD, a bus R-BUS, and a control word CLW. When an IO start instruction arrives at the line S2 from the controller C, the state of its channel is checked and then its corresponding input and output equipment address is used to read the table TBL, thereby checking the state of the corresponding IO in the TBL. |
