A pair of ground planes arranged in parallel, a dielectric medium disposed in between the pair of ground planes, and a set of at least four signal conductors disposed in the dielectric medium, the set of at least four signal conductors having (i) a first pair of signal conductors arranged proximate to a first ground plane of the pair of ground planes and (ii) a second pair of signal conductors arranged proximate to a second ground plane of the pair of ground planes, each signal conductor of the set of at least four signal conductors configured to carry a respective signal corresponding to a symbol of a codeword of a vector signaling code.

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.

Methods and systems are described for measuring a vertical opening of a signal eye of a pulse amplitude modulated (PAM) signal received over a channel to determine a vertically-centered voltage decision threshold of a sampler receiving a sampling clock, determining channel-characteristic parameters indicative of a frequency response of the channel, determining a correctional vernier value from the channel-characteristic parameters, and generating a horizontally-centered voltage decision threshold that introduces a horizontal sampling offset in the sampling clock in a direction closer to a horizontal center of the signal eye by combining the vertically-centered voltage decision threshold and the correctional vernier value.

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.

An efficient communications apparatus is described for a vector signaling code to transport data and optionally a clocking signal between integrated circuit devices. Methods of designing such apparatus and their associated codes based on a new metric herein called the “ISI Ratio” are described which permit higher communications speed, lower system power consumption, and reduced implementation complexity.

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.

Equalization methods and equalizers employing discrete-time filters are provided with dynamic perturbation effect based adaptation. Tap coefficient values may be individually perturbed during the equalization process and the effects on residual ISI monitored to estimate gradient components or rows of a difference matrix. The gradient or difference matrix components may be assembled and filtered to obtain components suitable for calculating tap coefficient updates with reduced adaptation noise. The dynamic perturbation effect based updates may be interpolated with precalculated perturbation effect based updates to enable faster convergence with better accommodation of analog component performance changes attributable to variations in process, supply voltage, and temperature.

A pair of ground planes arranged in parallel, a dielectric medium disposed in between the pair of ground planes, and a set of at least four signal conductors disposed in the dielectric medium, the set of at least four signal conductors having (i) a first pair of signal conductors arranged proximate to a first ground plane of the pair of ground planes and (ii) a second pair of signal conductors arranged proximate to a second ground plane of the pair of ground planes, each signal conductor of the set of at least four signal conductors configured to carry a respective signal corresponding to a symbol of a codeword of a vector signaling code.

Methods, systems, and devices for techniques for communicating multi-level signals are described. A first device may be configured to communicate signals with a second device according to a modulation scheme. The first device may transmit a first signal to the second device at a first voltage level of the modulation scheme corresponding to a first multi-bit value. The first device may select a second voltage level of the modulation scheme based on a difference between the first voltage level and a third voltage level of the PAM scheme, and may transmit a second signal to the second device at the second voltage level to indicate a second multi-bit value corresponding to the third voltage level. The second device may decode the second signal to determine the second multi-bit value based on receiving the first signal at the first voltage level and the second signal at the second voltage level.

Methods and systems are described for obtaining a set of carrier-modulated symbols of a carrier-modulated codeword, each carrier-modulated symbol received via a respective wire of a plurality of wires of a multi-wire bus, applying each carrier-modulated symbol of the set of carrier-modulated symbols to a corresponding transistor of a set of transistors, the set of transistors further connected to a pair of output nodes according to a sub-channel vector of a plurality of mutually orthogonal sub-channel vectors, recovering a demodulation signal from the carrier-modulated symbols, and generating a demodulated sub-channel data output as a differential voltage on the pair of output nodes based on a linear combination of the set of carrier-modulated symbols by controlling conductivity of the set of transistors according to the demodulation signal.