US Patent 7739533 Systems and methods for operational power management

Various systems and methods for power management are disclosed herein. For example, a synchronous semiconductor circuit is disclosed that includes two or more clock sources and a power management controller. The power management controller is operable to apply power to one of the clock sources and to select another of the clock sources for synchronization of the circuit. Then, upon stabilization of the first clock source, it is selected by the power management controller to synchronize the circuit.