Patent ID: 11874694
Assignee: ROHM CO., LTD.
Field: Computer technology (Electrical engineering)
Classification: CPC G  H | IPC G

Claim 0:
1. A semiconductor device comprising:
an oscillator configured to generate a first clock signal, wherein the oscillator is a ring oscillator that includes:
an odd number of inverters;
a DAC (DA converter) configured to perform DA conversion on a coarse adjustment instruction from the controller;
a current feeder configured to pass through the inverters a current corresponding to an output of the DAC; and
a mirror capacitance adjuster configured to change a capacitance value of a capacitance connected to a node among the inverters based on a fine adjustment instruction from the controller;

the semiconductor device further comprising:
a first terminal via which an input clock signal is fed in from outside;
a first counter configured to count a clock signal based on the first clock signal between edges in the input clock signal; and
a controller configured to send to the oscillator an instruction to adjust a frequency of the first clock signal based on a result of comparison of a count value by the first counter with an expected value.