| 摘要 |
PURPOSE:To select dynamically a processor unit which can switch a mode, by inserting a switching circuit into the pre-stage of a mode flip-flop whose mode is set by the processor unit. CONSTITUTION:A NOR gate 32 gains an OR condition of a mode changeover control signal outputted from a processor unit A and a mode changeover control signal outputted from a processor unit B, and supplies it to a clock input terminal of a mode flip-flop 31. An AND gate 33 gains an AND condition of a mode changeover control signal outputted from the processor unit B and a signal which has inverted an output of a switch 35 by an invertor 34, and supplies it to one input terminal of the NOR gate 32. The switch 35 selects to permit the mode changeover by both the processor units A, B, or to inhibit the mode changeover by the processor unit A. |
