| 摘要 |
<p>PURPOSE:To economize the power consumption in a semiconductor integrated circuit which is provided with an oscillating circuit, by stopping an oscillating operation of the oscillaing circuit in case of a holding mode. CONSTITUTION:In case when there is the possibility that supply voltage becomes lower than a normal value and a malfunction is caused, a transistor (TR) Q is turned off, and an external terminal 32n of an input/output port 31 is reversed to a high level. When an H flag of a status register 30 is set and a holding mode is set, a timing generator 34 inputs a clock pulse until 1 instruction cycle ends, and thereafter, stops generating a timing signal and also outputs an oscillation stop signal of a high level. In this way, when generation of a timing signal is stopped, the inside of a microcomputer except an oscillating circuit 33 becomes a stand-by state, and is set to a low power consumption state.</p> |
