| 摘要 |
PURPOSE:To efficiently transfer the status information to the arithmetic controller, by installing a selector which selectively outputs the status information of the input-output device to the input-output controller and a register which holds the status information. CONSTITUTION:When an input-output instruction is outputted from an arithmetic controller to an input-output controller 4, apparatus select signals UL1 and UL0 assigned from the controller 4 are outputted to I/O UNs 0-3 and a selector 10, and ready signals RDY0-RDY3 from prescribed I/Os are selectively inputted into the unit 4 through the selector 10, and thus, the processing is executed. This processing is performed only for a preset time. When the 2nd I/O is accessed from the arithmetic controller, the signals RDY0- RDY3 are held in a register 20 and the signals are transferred to the arithmetic controller. After a prearranged time, a reset signal FWCLR is inputted into the controller 4 through a gate 30 and the processing for the 1st I/O is temporarily stopped, and then, the processing for the 2nd I/O is performed for a prescribed time. After the Prescribed time has passed, the processing, for the 1st I/O is again started. |
