| 摘要 |
PURPOSE:To serve an optional service request with an optional interruption, by selecting the service request, which is designated by a control word, most preferentially. CONSTITUTION:A control word group to be stored in a memory 1 is regulated in accordance with predetermined priority levels, and the control word of the next address is read into a control word register 2 each time one service selection is terminated, and only SELOUT1 is outputted by the output of a decoder 3 when the service request for the highest priority level of REQIN1 is designated. If this service request is not designated, only one service request is selected in accordance with predetermined fixed priority levels. |
