1. Technical Field
The present invention relates to an oscillation circuit, an oscillator, an electronic device, a moving object, and a control method of an oscillator.
2. Related Art
An oscillator using a vibrator such as a quartz crystal resonator (piezoelectric vibrator) or a micro electro mechanical systems (MEMS) vibrator has been developed. Such an oscillator may have a special operation mode (for example, an operation mode for inspection, or an operation mode for setting information rewriting) used in manufacturing, in addition to an operation mode for normal use.
On the other hand, since a large number of terminals are not allowed for miniaturization of the oscillator, it may be difficult to provide an exclusive terminal for the special operation mode. For example, JP-A-9-294021 discloses a switch circuit in which analog/digital input and output terminals are commonly used in plural operation modes.
When an operation mode of an oscillator is switched by an electric potential or a signal input to a terminal, the operation mode may be erroneously switched due to affects of an unstable power source voltage, falling of thunderbolt, a physical shock, or the like.