| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve problems of a conventional one-chip microcomputer that has increased the cost because mechanical adjustment of an external damping resistor requires time and man-hours where the mechanical adjustment for each oscillator is used to eliminate harmonic noise and cannot execute harmonic correction including dispersion in the oscillation characteristic of each LSI. SOLUTION: This one-chip microcomputer, in which, a variable damping resistor with built in chip is connected to an output terminal of an oscillation inverter of the microcomputer having a self-excited oscillation function, is provided with a harmonic noise detection section that detects undesired radiation noise with an oscillation frequency, a correction value generating circuit, and a harmonic correction discrimination circuit that self-discriminates whether or not the correction value automatically calculated by the hardware is correctly set, is characterized in that it has a function of optimizing the resistance of the variable damping resistor with respect to the harmonic noise.</p> |
