CLOCK GENERATION DEVICE, METHOD OF OPERATING CLOCK GENERATION DEVICE, AND SYSTEM

摘要

PROBLEM TO BE SOLVED: To generate an output clock of a desired frequency from an input clock by means of a multiplication circuit of an arbitrary frequency specification.SOLUTION: A clock generation device includes: a first frequency division circuit for generating a first clock from an input clock by using a first division ratio; the multiplication circuit for generating a second clock from the first clock; and a second frequency division circuit for generating an output clock from the second clock by using a second division ratio. An expected value of a frequency of the second clock that the multiplication circuit can output is divided by a frequency of the first clock to produce an expected value of a multiplication number of the multiplication circuit. A product of an inverse number of a multiplication number that is a ratio of a frequency of the output clock to a frequency of the input clock and the expected value of the multiplication number thus produced is calculated, and an integral value resulting from dividing the calculated product by the first division ratio is determined as the second division ratio. A product of the multiplication number that is the ratio of the frequency of the output clock to the frequency of the input clock, the integral value and the first division ratio is calculated as the multiplication number given to the multiplication circuit.