A method of operating a clock signal source, the method comprising: (a) providing a control signal to the clock signal source; (b) detecting an output signal from the clock signal source; (c) measuring a value of a frequency of the output signal; (d) comparing the measured frequency value to a predetermined operating range of frequency values initially bounded by a lower end of an initial lower value and an upper end of an initial upper value and, if the measured frequency value is outside the predetermined operating range, then: (d) determining if the frequency of the output signal should or should not be changed; and (d) if it is determined that the frequency of the output signal should be changed, then modifying the control signal by a first predetermined value if the measured frequency is below the predetermined operating range or by a second predetermined value if the measured frequency is above the predetermined operating range; (e) providing the modified control signal to the clock signal source; and (f) repeating (b)-(e); wherein the clock signal source comprises a voltage regulator coupled to a voltage controlled oscillator, and wherein modifying the control signal provided to the clock signal source comprises: changing the control signal by one of the first or second predetermined values, wherein the first predetermined value causes an increase in an output of the voltage regulator by a first predetermined incrementing value and the second predetermined value causes causes a decrease in the output of the voltage regulator by a second predetermined decrementing value, wherein the clock signal source is a component of a system and wherein determining if the frequency of the output signal should or should not be changed is determined as a function of a current state of operation of the system. (a) providing a control signal to the clock signal source; (b) detecting an output signal from the clock signal source; (c) measuring a value of a frequency of the output signal; (d) comparing the measured frequency value to a predetermined operating range of frequency values initially bounded by a lower end of an initial lower value and an upper end of an initial upper value and, if the measured frequency value is outside the predetermined operating range, then: (d) determining if the frequency of the output signal should or should not be changed; and (d) if it is determined that the frequency of the output signal should be changed, then modifying the control signal by a first predetermined value if the measured frequency is below the predetermined operating range or by a second predetermined value if the measured frequency is above the predetermined operating range; (d) determining if the frequency of the output signal should or should not be changed; and (d) if it is determined that the frequency of the output signal should be changed, then modifying the control signal by a first predetermined value if the measured frequency is below the predetermined operating range or by a second predetermined value if the measured frequency is above the predetermined operating range; (e) providing the modified control signal to the clock signal source; and (f) repeating (b)-(e); <EOS>