A clock data calibration circuit including a first comparator, a multi-phase clock generator, a plurality of samplers, a plurality of data comparators and a data selector is provided. The first comparator compares first input data with second input data to generate a data signal. The multi-phase clock generator generates a plurality of clock signals, and the clock signals are divided into a plurality of clock groups. The sampler samples the data signal according to the clock groups to respectively generate a plurality of first sampled data signal groups. The data comparators respectively sample the first sampled data signal groups according to selected clocks to generate a plurality of second sampled data signal groups. Each data comparator generates a plurality of status flags according to a variation state of a plurality of second sampled data. The data selector generates a plurality of output data signals according to the status flags.

A clock data calibration circuit including a first comparator, a multi-phase clock generator, a plurality of samplers, a plurality of data comparators and a data selector is provided. The first comparator compares first input data with second input data to generate a data signal. The multi-phase clock generator generates a plurality of clock signals, and the clock signals are divided into a plurality of clock groups. The sampler samples the data signal according to the clock groups to respectively generate a plurality of first sampled data signal groups. The data comparators respectively sample the first sampled data signal groups according to selected clocks to generate a plurality of second sampled data signal groups. Each data comparator generates a plurality of status flags according to a variation state of a plurality of second sampled data. The data selector generates a plurality of output data signals according to the status flags.

Circuits, methods, and apparatus that may reconstruct a data signal in the presence of ground drift and high-frequency signal coupling. An illustrative embodiment of the present invention may reconstruct a received data signal by taking an finite difference of the received data signal, detecting edges of the received data signal by detecting positive and negative peaks of the finite difference of the received signal, and reconstructing the received data signal using the detected edges. Taking a finite difference of the received data signal removes the DC component of the received data signal, as well as the ground drift that may cause the DC component of the received data signal to change over time. Additional filtering may be used to reduce high-frequency signal coupling and power supply inductive coupling.

A clock and data recovery device includes a data sampling module, a phase detection circuit, a frequency estimator, a clock generation module, and a data recovery module. The data sampling module samples input data according to first clock signals to generate data values, in which phases of the first clock signals are different from one another. The phase detection circuit detects a phase error of the input data according to at least one second clock signal, to generate an error signal. The frequency estimator generates an adjustment signal according to the error signal, a phase threshold value, and a frequency threshold value. The clock generation module generates the first clock signals and the at least one second clock signal according to the adjustment signal and a reference clock signal. The data recovery module generates recovered data corresponding to the input data according to the data values.

The present invention is to reduce detection of an erroneous edge caused by variation in a case of a sampling frequency that is not larger than a data transmission frequency. A semiconductor device includes: a data reception circuit configured to receive first data at first time and receive second data at second time; and an edge recognition circuit configured to set a range and detect an edge contained in the range. The edge recognition circuit includes a measurement circuit configured to measure a first period taken from the reception of the first data to the reception of the second data, and is configured to determine the range in which the edge contained in the data that is received by the data reception circuit is detected, on the basis of the first period.

A clock generation circuit for generating a plurality of output clocks includes: a differential circuit for receiving a single input clock signal and outputting two differential clock signals, and a DC signal; a first polyphase filter for generating four clock signals from the differential clock signals which are a quadrature phase apart from each other; a plurality of setting buffers for setting a same DC point for the four clock signals and generating four resultant clock signals; coupled polyphase filters for generating four more clock signals which are a quadrature apart from each other, and outputting the resultant eight clock signals; a phase mixer, for generating eight output clock signals 45 degrees apart from each other; and a plurality of restoration buffers for setting a DC point for each of the eight clock signals and generating eight output clock signals all riding on a same DC point.

The present invention is to reduce detection of an erroneous edge caused by variation in a case of a sampling frequency that is not larger than a data transmission frequency. A semiconductor device includes: a data reception circuit configured to receive first data at first time and receive second data at second time; and an edge recognition circuit configured to set a range and detect an edge contained in the range. The edge recognition circuit includes a measurement circuit configured to measure a first period taken from the reception of the first data to the reception of the second data, and is configured to determine the range in which the edge contained in the data that is received by the data reception circuit is detected, on the basis of the first period.

A device includes feed-forward clock circuitry to provide a receiver (RX) clock to a sampler circuit that samples a data lane of a set of RX data lanes, the feed-forward clock circuitry having a temperature-induced delay. The device also includes an RX phase-locked loop (PLL) coupled between the feed-forward clock circuitry and the sampler circuit. The RX PLL includes a phase interpolator positioned in a feedback path of the RX PLL. The phase interpolator has a negative delay that matches the temperature-induced delay of the feed-forward clock circuitry to cause the sampler circuit to cancel out the common noise shared between the feed-forward clock circuitry and the data lane.

A device includes feed-forward clock circuitry to provide a receiver (RX) clock to a sampler circuit that samples a data lane of a set of RX data lanes, the feed-forward clock circuitry having a temperature-induced delay. The device also includes an RX phase-locked loop (PLL) coupled between the feed-forward clock circuitry and the sampler circuit. The RX PLL includes a phase interpolator positioned in a feedback path of the RX PLL. The phase interpolator has a negative delay that matches the temperature-induced delay of the feed-forward clock circuitry to cause the sampler circuit to cancel out the common noise shared between the feed-forward clock circuitry and the data lane.

Embodiments of this application disclose example phase detection methods, phase detection circuits, and clock recovery apparatuses. One example method includes receiving a first signal and deciding a (2M−1) level of the first signal to obtain a decision result, where the first signal is a (2M−1)-level signal, and M is a positive integer. A response amplitude parameter of a transmission channel can then be obtained. Clock phase information in the first signal can then be extracted based on the first signal, the decision result, and the response amplitude parameter. Output clock phase information can then be determined based on at least three decision results and at least three pieces of clock phase information in at least three symbol periods.