| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce power consumption in an integrated circuit by properly controlling a power supply voltage to be supplied in response to a supply situation of an external power supply. <P>SOLUTION: The integrated circuit is operated by applying the external power supply supplying a first power supply voltage. It is provided with a power supply voltage monitoring part monitoring a level of the first power supply voltage supplied from the external power supply to determine whether the first power supply voltage is supplied from the external power supply, a clock selecting part supplied with a first clock of a first frequency and a second clock having a second frequency lower than the first frequency, selecting the first clock if it is determined that the first power supply voltage is supplied in the power supply voltage monitoring part, and selecting and outputting the second clock if it is determined that the first power supply voltage is not supplied, and a processor operated by receiving supply of either one of the first clock or the second clock outputted by the clock selecting part, and controlling operation of the integrated circuit. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
