| 摘要 |
PROBLEM TO BE SOLVED: To comparatively inexpensively correct the fluctuation of an oscillation frequency caused by a temperature change. SOLUTION: First, a linear eguation is obtained as a temperature characteristic data showing the relation between the temperature and oscillation frequency of a crystal oscillator 10 in advance, and the temperature of the crystal oscillator 10 is detected in a fixed cycle by a diode 6 as a temperature detecting means. The oscillation frequency corresponding to the detected temperature is calculated from the said linear equation, and the frequency diving ratio of a built-in counter for dividing the frequency of an oscillated output from an oscillation circuit 11 is varied corresponding to the calculated oscillation frequency so that a reference clock can be provided in a fixed cycle regardless of the fluctuation of the oscillation frequency. |
