The oscillator circuit, a semiconductor device provided with the oscillator circuit, and a semiconductor memory device including the oscillator circuit

摘要

PPROBLEM TO BE SOLVED: To provide an oscillator circuit, which can acquire stable frequencies by stopping oscillating operations or not outputting oscillation signals in an unstable period of oscillation frequency at oscillation starting of the oscillator circuit in which operation and stop can be controlled. PSOLUTION: An oscillator 5 becomes in the state where oscillating operations is enabled by an oscillation enable signal (EN), and then a controller 4 starts operations. The controller 4 that starts operations changes an oscillation frequency control signal (VR) to a signal value corresponding to a specified oscillation frequency, and an oscillation frequency in the oscillator 5 is set. In addition, a detection signal (MON) is inputted into a detector 1 to be compared with a specified signal value, and outputted after detected that it reaches the specified signal value. When receiving the detection signal (MON), the oscillator 5 outputs an oscillation signal. Thereby, the transition state of VR can be detected, and unstable oscillation signals due to the transitional VR are not outputted. PCOPYRIGHT: (C)2006,JPO&NCIPI