| 摘要 |
<p>PURPOSE:To shorten the restart time of a prescribed operation by detecting the fluctuation of a source voltage set at an operation stopping state, and preserving the content of a memory register, etc., without initializing when no source voltage goes less than a constant voltage while the operation stopping state is set. CONSTITUTION:A microcomputer makes a source voltage fluctuation detection circuit 2 monitor the fluctuation of the source voltage after interrupting the execution of a program instruction with a stopping signal. When a state is shifted from a stopping state to an operating state, a data setting signal 11 on a program counter 12 is generated. When the state is shifted to the operating state without setting the source voltage fluctuation detection circuit 2 at this time, data setting on the program counter is prohibited with AND gates 9 and 10 even when the data setting signal 11 on the program counter 12 is generated, thereby, the content of the program counter is held. In such a way, a time required for the start of the prescribed operation can be reduced.</p> |
