Patent ID: 7714673
Filing Date: 2010-05-11
Classification: H03B

Abstract:
1. An apparatus for automatically controlling a plurality of operation modes of an oscillator and automatically switching the operation modes, comprising: a RC oscillator, for generating a first oscillated clock; a power-on reset circuit, for generating a reset signal; a control logic gate, coupled to the RC oscillator, for receiving the first oscillated clock and a confirming signal, and outputting a drive signal according to the first oscillated clock and the confirming signal; a plurality of T flip flops, coupled to the control logic gate, for receiving the drive signal and generating at least one option signal; a multi-mode oscillator, coupled to the T flip flops, having at least two input terminals for the plurality of operation modes, for receiving the at least one option signal and generating a second oscillated clock according to the option signal; and a finite state machine, coupled to the multi-mode oscillator and the control logic gate, for receiving the second oscillated clock and generating the confirming signal according to the received second oscillated clock.