Patent ID: 7928782

Claim:
A locked-loop operatively coupled to a device that can perform a plurality of operations, the locked-loop comprising: a phase adjusting device configured to receive a reference clock signal, the phase adjusting device being structured to generate an output clock signal having a phase relative to the phase of the reference clock signal that is determined by a phase control signal; a phase detector having a first input coupled to receive the reference clock signal and a second input coupled to receive the output clock signal, the phase detector being structured to generate a first output signal responsive to the phase of the reference clock signal less the phase of the output clock signal being greater than a first value, and being structured to generate a second output signal responsive to the phase of the output clock signal less the phase of the reference clock signal and being greater than a second value, the magnitude of at least one of the first and second values being controlled by a hysteresis control signal; a control circuit coupled to receive the first and second output signals from the phase detector, the control circuit being structured to generate a phase control signal that causes the phase adjusting device to increase the phase of the output clock signal relative to the phase of the reference clock signal responsive to the first output signal from the phase detector, the control circuit further being structured to generate a phase control signal that causes the phase adjusting device to decrease the phase of the output clock signal relative to the phase of the reference clock signal responsive to the second output signal from the phase detector; and a hysteresis controller coupled to the phase detector, the hysteresis controller being configured to determine the operation being performed by the device and provide the hysteresis control signal to the phase detector, the magnitude of at least one of the first and second values controlled by the hysteresis control signal being at least in part determined by the operation being performed by the device.