Voltage control for clock generating circuit

An apparatus comprising:

• a clock distribution network;
• at least one oscillator coupled to the clock distribution network so as to provide a clock signal on the clock distribution network;
• and
• a power control circuit to control power applied to the at least one oscillator, the power control circuit including:
• a bandgap device to produce a reference voltage based on a desired power level;
• and
• a decision device to receive the reference voltage from the bandgap device and to receive a voltage signal from a power source external to the apparatus, the decision device to determine whether the voltage signal received from the power source corresponds to the desired power level.

An apparatus comprising:

• a processor core having a voltage control circuit and at least one oscillator to produce core clock signals;
• and
• a power source located external to the core to provide power for the at least one oscillator based on a signal received from the processor core,
• the voltage control circuit including:
• a first device to produce a reference signal indicative of a desired power level to power the at least one oscillator;
• and
• a second device to receive the reference signal and to receive a signal from the power source, the second device to determine whether the signal received from the power source corresponds to the desired power level.