Semiconductor device and control methods thereof

A semiconductor device comprising:

• a first oscillator circuit generates an internal clock signal;
• a plurality of first clock monitoring circuit;
• and
• a mode switching circuit periodically switches an operation mode of the plurality of the first monitoring circuit to any of the first mode to third mode.
• wherein the first clock monitoring circuit comprises:
• a first clock counter;
• a first comparison circuit;
• and
• a first detection circuit;
• wherein one of the plurality of the first monitoring circuit executes a count processing which counts the number of the oscillation times by using the first clock counter at the first mode, executes a comparison processing which determines whether the number of the oscillation times is in a predetermined range by using the first comparison at the second mode, and executes a detection processing which detects whether a pulse from the output signal to the input signal is shifted or not by using the first detection circuit at the third mode.