| 摘要 |
A reference clock oscillating circuit intermittently carries out an oscillating operation on the basis of an oscillation control signal from an oscillation control circuit. A frequency multiplying circuit successively measures the period of a reference clock signal by using a measuring clock signal generated therein during a period for which the reference clock signal is input from the reference clock oscillating circuit, and generates a multiplied clock signal by using the period data thus measured. During a period for which no reference clock signal is input, the multiplied clock signal is generated by using the period data stored in a period data register. The interval of the intermittent oscillating operation is set on the basis of temperature variation of IC or the like.
|
