An apparatus for generating an oscillation signal is provided. The apparatus includes an input configured to receive a first reference oscillation signal, and a phase detector circuit configured to determine a phase drift of the first reference oscillation signal with respect to a second reference oscillation signal. Further, the apparatus includes a phase shifter circuit configured to generate the oscillation signal based on the first reference oscillation signal and a control signal. The control signal is based on the phase drift and a frequency control signal comprising control data for the phase shifter circuit for adjusting a frequency of the oscillation signal to a desired frequency.

In an audio processing apparatus configured to supply audio data to a processor configured to process audio data, a plurality of receivers, each configured to receive audio data and a work clock carried with the audio data and to supply the audio data to the processor; a plurality of PLL circuits corresponding to the plurality of receivers, each PLL circuit being configured to generate a clock signal based on a word clock received by the corresponding receiver; and a selector configured to select a clock signal from among a plurality of clock signals generated by the plurality of PLL circuits, and to supply the selected clock signal to the processor, the processor outputting the processed audio data at timing synchronized with the selected clock signal are provided.

A phase locked loop includes a signal receiver configured to generate a mixed signal based on the received signal and an oscillator signal, and a frequency control circuit configured to compare the mixed signal to a reference signal, and adjust the oscillator signal based on a result of the comparing.

In accordance with embodiments disclosed herein, there is provided systems and methods for link training between a host device and a device. The host device includes a clock source, front-end circuitry, a duty cycle monitor (DCM), link training logic, and a duty cycle adjustor (DCA). The front-end circuitry is to transmit a training sequence and a forward clock signal to the device and is to receive a strobe signal from the device over a physical transmission media. The DCM is to monitor duty cycle of the strobe signal and duty cycle of the clock signal. The link training logic is to determine a adjustment to the clock signal and is to generate a control signal. The DCA is to receive the clock signal and the control signal and is to adjust the clock signal to generate an adjusted forward clock signal in view of the control signal.

An objective of the present technology is to provide a transmission device, a reception device, and a transceiver system of which miniaturization can be achieved. The transmission device includes an oscillator configured to oscillate a first clock signal; and a register signal reception unit configured to receive a register signal transmitted from a reception device and used for controlling the first clock signal. The reception device includes a signal generation unit configured to generate a register signal for controlling a first clock signal transmitted from the transmission device based on a comparison result obtained by comparing a reference clock signal with one of the first clock signal and a second clock signal which is based on the first clock signal; and a register signal transmission unit configured to transmit the register signal generated by the signal generation unit to the transmission device.

A system for time synchronization of a network element including a GNSS receiver operative to receive at least one signal from at least one but less than four GNSS satellites, a locator operative to supply a location of a network element including the GNSS receiver to the GNSS receiver and a time synchronization calculator operative to time synchronize the network element with the GNSS satellites based on the at least one signal and the location.

Disclosed are circuits and method for reducing or eliminating reference spurs in frequency synthesizers. In some implementations, a phase-locked loop (PLL) such as a Frac-N PLL of a frequency synthesizer can include a phase frequency detector (PFD) configured to receive a reference signal and a feedback signal. The PFD can be configured to generate a first signal representative of a phase difference between the reference signal and the feedback signal. The PLL can further include a compensation circuit configured to generate a compensation signal based on the first signal. The PLL can further includes a voltage-controlled oscillator (VCO) configured to generate an output signal based on the compensation signal. The compensation signal can include at least one feature for substantially eliminating one or more reference spurs associated with the PLL.

An apparatus is disclosed that implements phase-locked loop (PLL) calibration. In an example aspect, the apparatus includes a PLL and a signal extraction path. The PLL includes an error determiner with an error output node and a loop filter with a filter input node and a filter output node. The filter input node is coupled to the error output node. The PLL also includes a voltage-controlled oscillator (VCO) with a VCO input node. The VCO input node is coupled to the filter output node. The PLL further includes a PLL tap node coupled between the filter output node and the VCO input node. The signal extraction path includes at least one switch, with the signal extraction path coupled to the PLL tap node.

A clock and data recovery circuit includes a first sampling phase detector and filter circuitry, a frequency detector circuit, a current source circuit, a band controller circuit, and a voltage controlled oscillator. The first sampling phase detector and filter circuitry generates a first voltage according to a pair of data and a first set of clock signals. The frequency detector circuit generates an up control signal and a down control signal according to the pair of data and the first set of clock signals. The current source circuit generates the first voltage according to the up control signal and the down control signal. The band controller circuit generates a band control signal according to the first voltage. The voltage controlled oscillator adjusts the first set of clock signals according to the band control signal and the first voltage.

An eye width monitor (EWM) for a clock and data recovery (CDR) circuit includes a delay circuit, a first multiplexer (MUX) and a calibration circuit. The delay circuit includes an input terminal and an output terminal. The first MUX, coupled to the delay circuit, includes a first input terminal, a second input terminal and an output terminal. The first input terminal of the first MUX is coupled to a clock input terminal of the EWM. The second input terminal of the first MUX is coupled to the output terminal of the delay circuit. The output terminal of the first MUX is coupled to the input terminal of the delay circuit. The calibration circuit, coupled to the delay circuit, is configured to receive an oscillation clock from the delay circuit and receive a reference clock, and calibrate the oscillation clock with the reference clock.