Abstract: Apparatus and associated methods relating to reducing lock time include pre-calibrating and storing phase-locked loop (PLL) and/or injection-locked oscillator (ILO) adaptation values during startup and loading the pre-calibrated values during rate change. In an illustrative example, an integrated circuit may include a controllable frequency circuit operable at frequencies within each of a plurality of frequency bands. A data store may store operational settings associated with each frequency of the plurality of frequency bands. A state machine may be coupled to the controllable frequency circuit and the data store configured to select a predetermined frequency band in response to a command signal, retrieve, from the data store, operational settings associated with the predetermined frequency band, and, apply the retrieved operational settings to the controllable frequency circuit.

Abstract: Apparatus and associated methods relating to reducing lock time include pre-calibrating and storing phase-locked loop (PLL) and/or injection-locked oscillator (ILO) adaptation values during startup and loading the pre-calibrated values during rate change. In an illustrative example, an integrated circuit may include a controllable frequency circuit operable at frequencies within each of a plurality of frequency bands. A data store may store operational settings associated with each frequency of the plurality of frequency bands. A state machine may be coupled to the controllable frequency circuit and the data store configured to select a predetermined frequency band in response to a command signal, retrieve, from the data store, operational settings associated with the predetermined frequency band, and, apply the retrieved operational settings to the controllable frequency circuit.

Abstract: An example method of clock and data recovery in a receiver includes generating data samples and crossing samples of a received signal based on a data clock signal and a crossing clock signal, respectively, which are derived from a sampling clock signal; adjusting a phase of the sampling clock signal using a clock and data recovery (CDR) circuit based on the data samples and the crossing samples; adjusting relative phase between the data clock signal and the crossing clock signal from a first phase difference to a second phase difference that is less than ninety degrees; and reverting the relative phase between the data clock signal and the crossing clock signal to the first phase difference after a threshold time period.

Abstract: An example method of clock and data recovery in a receiver includes generating data samples and crossing samples of a received signal based on a data phase and a crossing phase, respectively, of a sampling clock supplied by a phase interpolator in the receiver; generating a phase detect result signal in response to phase detection of the data samples and the crossing samples; filtering the phase detect result signal to generate a phase interpolator code, the phase interpolator generating the sampling clock based on the phase interpolator code; determining an average phase detect result from the phase detect result signal; and adjusting the phase interpolator code in response to the average phase detect result being less than a threshold value.

Abstract: A method relates generally to a receiver. In such a method, a check of a clock and data recovery block of the receiver for a metastable state is performed. A phase input to a phase interpolator of the receiver is changed to cause the clock and data recovery block of the receiver to exit the metastable state within a time limit. To check for the metastable state, a phase difference in received data is determined, and the phase difference is determined to be less than a threshold for the clock and data recovery block being in the metastable state.