Clock control circuit for microcomputer, corrects frequency of second clock signal based on first clock signal, and monitors oscillation state of first clock signal based on second clock signal

摘要

The circuit includes an oscillator circuit for producing a first clock signal using an oscillator. A CR oscillator circuit produces a second clock signal of lower frequency. A correction circuit corrects the oscillation frequency of the second clock signal based on the first clock signal. A monitoring circuit monitors the oscillation state of the first clock signal based on the second clock signal. Independent claims are included for a microcomputer; a method of setting the oscillation frequency of a clock signal in a microcomputer; and oscillator device; a further microcomputer; and a memory interface circuit