Abstract: Multi-drop communications channels can have significantly deep notches in their frequency response causing a corresponding limitation of the effective data transmission rate. A special time-ordered coding method is described which results in the emitted spectrum of the data stream transmitted into the channel having a notch at the same frequency as the notch in the channel frequency response, permitting channel receivers to successfully decode the transmitted data stream. The described coding method may be applied at various multiples of the channel notch frequency to support different throughput rates, and may be combined with other coding techniques such as group or vector signaling codes.

Abstract: Methods and systems are described for obtaining, at a phase-error aggregator, a plurality of data-derived phase-error signals for two or more data lanes of a multi-wire bus, each data-derived phase-error signal generated using at least (i) a phase of one or more phases of a local oscillator signal and (ii) a corresponding data signal associated with one of the two or more data lanes, generating a composite phase-error signal representing a combination of the two or more obtained data-derived phase-error signals, receiving the composite phase-error signal at a loop filter responsively generating an oscillator control signal, and receiving the oscillator control signal at a local oscillator and responsively adjusting a timing of the local oscillator to adjust the one or more phases of the local oscillator signal.

Abstract: 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.

Abstract: Methods and systems are described for receiving signal elements corresponding to a first group of symbols of a vector signaling codeword over a first densely-routed wire group of a multi-wire bus at a first set of multi-input comparators (MICs), receiving signal elements corresponding to a second group of symbols of the vector signaling codeword over a second densely-routed wire group of the multi-wire bus at a second set of MICs, and receiving signal elements corresponding to the first and the second groups of symbols of the vector signaling codeword at a global MIC.

Abstract: 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.

Abstract: Methods and systems are described for obtaining, at a phase-error aggregator, a plurality of data-derived phase-error signals for two or more data lanes of a multi-wire bus, each data-derived phase-error signal generated using at least (i) a phase of one or more phases of a local oscillator signal and (ii) a corresponding data signal associated with one of the two or more data lanes, generating a composite phase-error signal representing a combination of the two or more obtained data-derived phase-error signals, receiving the composite phase-error signal at a loop filter responsively generating an oscillator control signal, and receiving the oscillator control signal at a local oscillator and responsively adjusting a timing of the local oscillator to adjust the one or more phases of the local oscillator signal.

Abstract: Methods and systems are described for receiving a sampling signal, pre-charging a pair of output nodes prior to a sampling interval, initiating the sampling interval by enabling a current source according to a first transition of the received sampling signal, generating a differential output voltage at the pair of output nodes by discharging the pair of output nodes according to a differential input signal, the pair of output nodes discharged according to current drawn by the current source during the sampling interval, terminating the sampling interval by disabling the current source in response to a second transition of the received sampling signal, and inhibiting a recharge of the pair of output nodes for a hold time after termination of the sampling interval and prior to initiation of a subsequent sampling interval.

Abstract: Methods and systems are described for receiving, over a plurality of consecutive signaling intervals, a plurality of codewords, each codeword received as a plurality of symbols via wires of a multi-wire bus, the plurality of symbols received at a plurality of multi-input comparators (MICs), wherein each symbol is received by at least two MICs, generating, for each codeword, a corresponding linear combination of the received symbols, generating a plurality of composite skew measurement signals over the plurality of consecutive signaling intervals, each composite skew measurement signal based on samples of one or more linear combinations, and updating wire-specific skew values of the wires of the multi-wire bus, wherein one or more wire-specific skew values are updated according to composite skew measurement signals associated with linear combinations formed by at least two different MICs.

Abstract: Multi-drop communications channels can have significantly deep notches in their frequency response causing a corresponding limitation of the effective data transmission rate. A special time-ordered coding method is described which results in the emitted spectrum of the data stream transmitted into the channel having a notch at the same frequency as the notch in the channel frequency response, permitting channel receivers to successfully decode the transmitted data stream. The described coding method may be applied at various multiples of the channel notch frequency to support different throughput rates, and may be combined with other coding techniques such as group or vector signaling codes.

Abstract: Transmission of baseband and carrier-modulated vector codewords, using a plurality of encoders, each encoder configured to receive information bits and to generate a set of baseband-encoded symbols representing a vector codeword; one or more modulation circuits, each modulation circuit configured to operate on a corresponding set of baseband-encoded symbols, and using a respective unique carrier frequency, to generate a set of carrier-modulated encoded symbols; and, a summation circuit configured to generate a set of wire-specific outputs, each wire-specific output representing a sum of respective symbols of the carrier-modulated encoded symbols and at least one set of baseband-encoded symbols.

Abstract: Methods and systems are described for receiving symbols of a codeword via wires of a multi-wire bus, the codeword representing an aggregate sum of a plurality of sub-channel constituent codewords, each sub-channel constituent codeword representing a weight applied to an associated sub-channel vector of a plurality of sub-channel vectors of an orthogonal matrix, generating a plurality of comparator outputs using a plurality of common-mode resistant multi-input comparators (MICs), each common-mode resistant MIC having a set of input coefficients representing a corresponding sub-channel vector of the plurality of sub-channel vectors, each sub-channel vector (i) mutually orthogonal and (ii) orthogonal to a common-mode sub-channel vector, outputting a set of forward-channel output bits formed based on the plurality of comparator outputs, obtaining a sequence of reverse-channel bits, and transmitting the sequence of reverse-channel bits by sequentially transmitting common-mode codewords over the wires of the multi-

Abstract: 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 indication, the phase error indication selected in response to identification of a predetermined data decision pattern.

Abstract: 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.

Abstract: Methods and systems are described for obtaining a plurality of information bits, and responsively partitioning the obtained plurality of information bits into a plurality of subsets of information bits, generating a plurality of streams of forward error correction (FEC)-encoded bits using a plurality of FEC encoders receiving respective subsets of the plurality of subsets of information bits, providing the plurality of streams of FEC-encoded bits to a plurality of sub-channel encoders, each sub-channel encoder receiving a respective stream of FEC-encoded bits from a different FEC encoder of the plurality of FEC encoders for generating a set of codewords of a vector signaling code, and wherein sequential streams of FEC-encoded bits from a given FEC encoder are provided to different sub-channel encoders for each successively generated set of codewords, and transmitting the successively generated sets of codewords of the vector signaling code over a multi-wire bus.

Abstract: 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.

Abstract: Multi-mode non-return-to-zero (NRZ) and orthogonal differential vector signaling (ODVS) clock and data recovery circuits having configurable sub-channel multi-input comparator (MIC) circuits for forming a composite phase-error signal from a plurality of data-driven phase-error signals generated using phase detectors in a plurality of receivers configured as ODVS sub-channel MICs generating orthogonal sub-channel outputs in a first mode and a separate first and second data driven phase-error signal from two receivers of a plurality of receivers configured as NRZ receivers in a second mode.

Abstract: Methods and systems are described for receiving symbols of a codeword via wires of a multi-wire bus, the codeword representing an aggregate sum of a plurality of sub-channel constituent codewords, each sub-channel constituent codeword representing a weight applied to an associated sub-channel vector of a plurality of sub-channel vectors of an orthogonal matrix, generating a plurality of comparator outputs using a plurality of common-mode resistant multi-input comparators (MICs), each common-mode resistant MIC having a set of input coefficients representing a corresponding sub-channel vector of the plurality of sub-channel vectors, each sub-channel vector (i) mutually orthogonal and (ii) orthogonal to a common-mode sub-channel vector, outputting a set of forward-channel output bits formed based on the plurality of comparator outputs, obtaining a sequence of reverse-channel bits, and transmitting the sequence of reverse-channel bits by sequentially transmitting common-mode codewords over the wires of the multi-

Abstract: Transmission of baseband and carrier-modulated vector codewords, using a plurality of encoders, each encoder configured to receive information bits and to generate a set of baseband-encoded symbols representing a vector codeword; one or more modulation circuits, each modulation circuit configured to operate on a corresponding set of baseband-encoded symbols, and using a respective unique carrier frequency, to generate a set of carrier-modulated encoded symbols; and, a summation circuit configured to generate a set of wire-specific outputs, each wire-specific output representing a sum of respective symbols of the carrier-modulated encoded symbols and at least one set of baseband-encoded symbols.

Abstract: Systems and methods are described for transmitting data over physical channels to provide a high bandwidth, low latency interface between a transmitting device and a receiving device operating at high speed with low power utilization. Communication is performed using group signaling over sets of four wires using a vector signaling code, where each wire of a set carries a low-swing signal that may take on one of four signal values. Topologies and designs of wire sets are disclosed with preferred characteristics for group signaling communications.

Abstract: Multi-drop communications channels can have significantly deep notches in their frequency response causing a corresponding limitation of the effective data transmission rate. A special time-ordered coding method is described which results in the emitted spectrum of the data stream transmitted into the channel having a notch at the same frequency as the notch in the channel frequency response, permitting channel receivers to successfully decode the transmitted data stream. The described coding method may be applied at various multiples of the channel notch frequency to support different throughput rates, and may be combined with other coding techniques such as group or vector signaling codes.