Patent ID: 7388437

Claim:
An apparatus for generating an output signal having a particular frequency, comprising: an oscillator operable to generate an output signal associated with an output frequency; a first tuning module operable, when coupled to the oscillator, to induce changes in the output frequency, wherein the first tuning module is operable to induce changes in the output frequency of a particular magnitude within a first amount of time; a second tuning module operable, when coupled to the oscillator, to induce changes in the output frequency, wherein the second tuning module is operable to induce changes in the output frequency of the particular magnitude within a second amount of time, wherein the second amount of time is greater than the first amount of time; a frequency divider operable to: receive information indicating a divisor associated with a requested frequency; generate a divided signal, wherein the divided signal is associated with a frequency equal to the output frequency divided by the divisor; and a selector operable to couple at least a selected one of the first tuning module and the second tuning module to the oscillator based, at least in part, on a difference between the divided signal and a reference signal; wherein the first tuning module comprises: a first counter operable to count a quantity of edges in the divided signal; a second counter operable to count a quantity of edges in a reference signal; a comparator operable to compare a first count output by the first counter to a second count output by the second counter; and a trigger element operable to store a first output of the comparator; and wherein the first tuning module is operable to: increase the output frequency associated with the output signal if the first count is less than the second count; and decrease the output frequency associated with the output signal if the first count is greater than the second count; and wherein the selector is operable to: couple the second tuning module to the oscillator if the first count is equal to the second count; and couple the second tuning module to the oscillator based, at least in part, on the stored first output and a second output of the comparator.