| 摘要 |
<p>PURPOSE:To eliminate the need of an input terminal for inputting a release signal from the outside by providing a circuit for detecting a voltage variation and a stand-by control circuit for releasing a stand-by state of a built-in CPU and setting it to an operating state. CONSTITUTION:When a power supply voltage inputted from a terminal 51 is boosted from a stand-by state to a voltage corresponding to an operating state of a microcomputer, its voltage rise is inputted to an edge detecting circuit 4 through a delaying circuit 3 and detected, and a stand-by releasing signal is outputted and inputted to a stand-by control circuit 6. In the stand-by control circuit 6, by receiving an input of the stand-by releasing signal, a stand-by state of a CPU 7 is released, and the microcomputer becomes an operating state. In such a way, an exclusive terminal for releasing the stand-by state from the outside becomes unnecessary.</p> |
