Generating, during a first and second signaling interval, an aggregated data signal by forming a linear combination of wire signals received in parallel from wires of a multi-wire bus, wherein at least some of the wire signals undergo a signal level transition during the first and second signaling interval; measuring a signal skew characteristic of the aggregated data signal; and, generating wire-specific skew offset metrics, each wire-specific skew offset metric based on the signal skew characteristic.

A receiver includes an equalization circuit configured to output a data sample signal and an edge sample signal by sampling a data input signal according to clock signal, and to perform an equalization operation according to the data sample signal and the edge sample signal; and a clock gate circuit configured to select the clock signals from among a plurality of multi-phase clock signals according to a selection signal.

A signaling system includes a pre-emphasizing transmitter and an equalizing receiver coupled to one another via a high-speed signal path. The receiver measures the quality of data conveyed from the transmitter. A controller uses this information and other information to adaptively establish appropriate transmit pre-emphasis and receive equalization settings, e.g. to select the lowest power setting for which the signaling system provides some minimum communication bandwidth without exceeding a desired bit-error rate.

An apparatus is described and includes a current integrating phase interpolator core having a programmable bias current; an AC-coupled inverter circuit coupled to an output of the current integrating phase interpolator core for receiving a signal comprising a periodic sawtooth waveform therefrom; a digital-to-analog (D/A) converter for setting an input common mode voltage of the AC-coupled inverter circuit; a duty cycle measurement (DCM) circuit for measuring a duty cycle distortion (DCD) of a rectangular wave clock signal output from the AC-coupled inverter circuit; and a circuit for computing a difference in the DCD of the rectangular wave clock signal when the input common mode voltage of the AC-coupled inverter circuit is set to a high voltage and when the input common mode voltage of the AC-coupled inverter circuit is set to a low voltage.

A phase interpolator of a physical layer (PHY) device comprise a phase interpolator to generate a set of asynchronous sampler clocks. A sampler of the PHY device samples a calibration data pattern using a first sampler clock from the set of asynchronous sampler clocks. A calibration control component of the PHY device detects a misalignment of a phase relationship among the set of asynchronous sampler clocks based on the sampled data. In response to detecting the misalignment, the calibration control component calibrates the first sampler clock using a second sampler clock and a third sampler clock.

Methods and systems are described for generating two comparator outputs by comparing a received signal to a first threshold and a second threshold according to a sampling clock, the first and second thresholds determined by an estimated amount of inter-symbol interference on a multi-wire bus, selecting one of the two comparator outputs as a data decision, the selection based on at least one prior data decision, and selecting one of the two comparator outputs as a phase-error decision, the phase error decision selected in response to identification of a predetermined data decision pattern.

A clock synchronization packet exchanging method includes sending, by a first device in a Flexible Ethernet (FlexE) group, a first FlexE instance at a first physical layer (PHY), where the first FlexE instance includes a clock synchronization packet, and a second FlexE instance sent by the first device in the FlexE group at a second PHY also includes a clock synchronization packet. The clock synchronization packets are carried in a plurality of FlexE instances transmitted between a transmit end and a receive end in the FlexE group.

A network transceiver device is provided, including at least two variable gain amplifiers (VGAs), and at least two sets of analog digital converters (ADCs), each set including ADCs coupled to an output of one of the VGAs, the sets being arranged in VGA-specific channels. The device includes a plurality of feed-forward equalizers (FFEs), each FFE being coupled to receive an output of one of the ADCs in one of the VGA-specific channels. Each FFE is configured to adaptively equalize the output received from the ADCs utilizing a first equalization coefficient subset with coefficient values that are common to all FFEs, and a second equalization coefficient subset that is channel specific and that has a first set of coefficient values for a first VGA-specific channel and a second set of coefficient values for a second VGA-specific channel, the sets of coefficient values being computed independently.

Methods, apparatus, and systems to synchronize Ethernet signals are disclosed. An example apparatus includes slicer circuitry having an input coupled to interface circuitry and having an output, the slicer circuitry configured to receive an analog signal corresponding to a first Analog to Digital Converter (ADC) clock in a plurality of ADC clocks and operable to determine symbols based on the analog signal; logic circuitry to determine whether there is a symbol transition in the symbols; timing error detector circuitry to update an error value in response to the determination that there is a symbol transition; timing loop circuitry to determine a frequency of voltage oscillations based on at least the error value; and phase interpolator circuitry to change a plurality of phase parameters corresponding to the plurality of ADC clocks at a rate given by the frequency of voltage oscillations.

Generating, during a first and second signaling interval, an aggregated data signal by forming a linear combination of wire signals received in parallel from wires of a multi-wire bus, wherein at least some of the wire signals undergo a signal level transition during the first and second signaling interval; measuring a signal skew characteristic of the aggregated data signal; and, generating wire-specific skew offset metrics, each wire-specific skew offset metric based on the signal skew characteristic.