OSCILLATION FREQUENCY ADJUSTMENT CIRCUIT, SEMICONDUCTOR DEVICE, ELECTRONIC APPARATUS, AND OSCILLATION FREQUENCY ADJUSTMENT METHOD

摘要

PROBLEM TO BE SOLVED: To solve the problem that an overflow value is a fixed value, count time is fixed and it takes time for adjustment and tests.SOLUTION: An oscillation frequency adjustment circuit includes: a counter 3 for performing measurement on the basis of an oscillation frequency of a CR oscillation circuit 2; a comparator 4 for comparing a measured value of the oscillation frequency that is measured and a set comparison value for set comparison time; a setting part (selector 5) for setting the comparison value selected from the plurality of comparison values of different sizes and the comparison time according to the size of the selected comparison value to the comparison part; and an adjustment part (DEF, logical operation circuit) for adjusting the oscillation frequency of the CR oscillation circuit 2 so that the oscillation frequency measured in the counter 3 becomes a target oscillation frequency on the basis of a comparison result of the comparator 4. Adjustment is performed by the small comparison value and the short comparison time up to the prescribed number of times of adjustment, and the adjustment is performed by the large comparison value and long second comparison time when exceeding the prescribed number of times.