A clock and data recovery circuit includes a voltage controlled oscillator, a frequency detector and a control circuit. The voltage controlled oscillator is configured to generate a clock signal according to a voltage signal. The frequency detector is configured to detect whether increasing a frequency of the clock signal is required according to a plurality of sampling results of the input data signal and accordingly generate a first up control signal. The control circuit is coupled to the voltage controlled oscillator and the frequency detector and configured to adjust the voltage signal according to the first up control signal. The clock and data recovery circuit operates in a data recovery mode after detecting that the frequency of the clock signal is locked, and the frequency detector is configured to detect whether increasing the frequency of the clock signal is required in the data recovery mode.

A clock calibration module, a high-speed receiver, and an associated calibration method are provided. The calibration method is applied to the high-speed receiver having the clock calibration module and a sampler. The sampler samples an equalized data signal with a sampler-input clock. The clock calibration module includes multiple clock generation circuits and a clock calibration circuit. Each of the clock generation circuits includes a phase interpolator, a duty cycle corrector, and a phase corrector. In a calibration mode, the phase interpolator interpolates a reference input clock and generates an interpolated clock accordingly. The duty cycle corrector generates a duty cycle corrected clock based on the interpolated clock. The phase corrector generates the sampler-input clock based on the duty cycle corrected clock. The phase interpolator is controlled by a phase interpolator calibration signal, and the phase corrector is controlled by a phase corrector calibration signal.

An apparatus for generating an output signal having a waveform that is repeated every period, includes a storage configured to store values corresponding to the waveform in a portion of a period of the output signal, a counter configured to generate a first index of a sample included in the output signal, a controller configured to generate at least one control signal based on the first index and the period of the output signal, and a calculation circuit configured to generate the output signal by calculating an output from the storage based on the at least one control signal.

A method for controlling a phase-locked loop circuit, can include: acquiring values of a voltage-controlled oscillator capacitor array control signal respectively corresponding to desired values of a frequency control word signal and acquiring values of a charge pump current control signal respectively corresponding to the desired values of the frequency control word signal in a calibration mode, where the frequency control word signal characterizes a ratio of a desired locked frequency to a frequency of a reference signal; and determining a target value of the voltage-controlled oscillator capacitor array control signal corresponding to a target value of the frequency control word signal and a target value of the charge pump current control signal corresponding to the target value of the frequency control word signal in a phase-locked mode, in order to control the phase-locked loop circuit to achieve phase lock.

A transmitter includes a modulator configured to digitally generate a communication signal whose modulation represents coded information to be transmitted to a local management unit. The transmitter can include a control unit configured to generate harmonic frequencies that are in-phase, inverted, or out-of-phase from a raw signal using fundamental frequencies for modulation.

A transmitter includes a modulator configured to digitally generate a communication signal whose modulation represents coded information to be transmitted to a local management unit. The transmitter can include a control unit configured to generate harmonic frequencies that are in-phase, inverted, or out-of-phase from a raw signal using fundamental frequencies for modulation.

A semiconductor device has a current controlled oscillation circuit configured to generate an oscillation clock in response to a current supplied, a first circuit configured to output a first signal when a phase of the oscillation clock is later than a phase of reception data, and to output a second signal when a phase of the oscillation clock is earlier than a phase of the reception data, and a current control circuit configured to control a current to be supplied to the current controlled oscillation circuit such that the number of times of output of the first signal from the first circuit matches the number of times of output of the second signal from the first circuit.

A circuit includes a voltage-controlled oscillator (VCO) and a frequency divider. The frequency divider input is coupled to the VCO output. The circuit further includes a phase-frequency detector (PFD). A control output of the PFD is coupled to the VCO. A first PFD input is coupled to a first frequency divider output, and a second PFD input is coupled to a second frequency divider output. The first frequency divider output is configured to provide a first frequency divider signal and the second frequency divider output is configured to provide a second frequency divider signal 90 degrees out of phase with respect to the first frequency divider signal. The PFD is configured to detect an occurrence of at least two edges of a signal on the data input while the second frequency divider signal is continuously logic high across the at least two edges.

A clock recovery circuit includes a clock detector configured to receive a serial data stream from a remote device over a reverse channel, wherein the serial data stream includes clock reference data, reverse channel data, or a combination of the clock reference data and the reverse channel data, and the clock detector configured to output a clock detect signal in response to detecting the clock reference data in the serial data stream; a phase lock loop including a first detector configured to receive the serial data stream and to detect phase and frequency; and a controller configured to receive the clock detect signal and to selectively enable the first detector based on the clock detect signal.

A data transmitting and receiving system includes a first device including an encoder configured to encode row data to generate precoding data and a transmitter configured to transmit the precoding data through a transmission channel and a second device including an integrator configured to perform an integral on the precoding data, an integral sampler including a plurality of samplers configured to output sampling data based on an offset value and an output value of the integrator, a decoder configured to decode outputs of some of the samplers to generate decoded data, and a phase detector configured to detect a phase difference between the precoding data and a clock based on the decoded data and an output of another one of the samplers.