The present invention is made to resolve problems of the above described
prior art. Prime object of the present invention is to provide an
oscillator circuit capable of outputting oscillation signal with stable
oscillation frequency, a semiconductor device and a semiconductor memory
device provided with the oscillator circuit, and control method of the
oscillator circuit. For achieving the prime object, there are taken the
following countermeasures at the time of initiating oscillation where the
inventive oscillator circuit can control to operate/stop oscillation. That
is, the countermeasures to be taken are: (1) oscillation operation is
stopped or an output of an oscillation signal is not permitted while
transient oscillation frequency is unstable; or (2) a period that
transient oscillation frequency is unstable is shortened.
