75 results about "Skew" patented technology

Time-interleaved signal converter systems are provided that multiplex respective digital sequences of system converters into an interleaved digital sequence before filtering each respective digital sequence with digital filters that apply respective filter coefficients to thereby reduce system degradation caused by converter timing skews. Use of the interleaved digital sequence in the filtering process substantially increases the system bandwidth from approximately one half of the converter sample rate RC to approximately one half of a greater system sample rate RS. Converter system embodiments are preferably configured to reduce large timing skews prior to filtering the interleaved digital sequence to obtain further reduction. This combined approach has been found to enhance interleaved system performance.

Systems and methods for determining inline skew of one or more seismic streamers are disclosed. One system embodiment includes a seismic streamer including a plurality of receivers, a skew detector adapted to detect inline skew of the streamer, and a receiver selector adapted to select which receivers in the streamer to use in data acquisition based on the detected streamer inline skew. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

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 applies a calibration method to compensate for skew between input channels. The receiver skew is estimated by observing the coefficients of an adaptive equalizer which adjusts the coefficients based on time-varying properties of the multi-channel input signal. The receiver skew is compensated by programming the phase of the sampling clocks for the different channels. Furthermore, during real-time operation of the receiver, channel diagnostics is performed to automatically estimate differential group delay and / or other channel characteristics based on the equalizer coefficients using a frequency averaging or polarization averaging approach. Framer information can furthermore be utilized to estimate differential group delay that is an integer multiple of the symbol rate. Additionally, a DSP reset may be performed when substantial signal degradation is detected based on the channel diagnostics information.

An HDMI cable may exhibit frequency dependent signal attenuation, inter symbol interference, and inter-pair skew. A boost device integrated with the cable can compensate for such impairments of the cable. A self calibrating cable with a boost device of the embodiment of the invention is described, in which parameters that control the response of the boost device are set optimally in a self-calibrating process comprising looping the boosted cable on itself through a calibration fixture that contains a calibration control device. The boost device includes pattern generators and a sampling circuit. Each high speed channel of the cable is separately tested and calibrated with the help of one of the other channels serving as a sampling channel.

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 data handoff controller includes a counter coupled to supply a count value indicative of a skew between a first clock signal and a second clock signal. The first and second clock signal have a fundamental beat frequency. A greatest common factor circuit is used to determine the fundamental beat frequency and the second is reset based on the beat frequency. A sampling circuit samples first clock domain data with the second clock signal. The sampling circuit is controlled to sample, at least in part, based on the count value. The count value can be used to impose a blackout window in which data is not sampled to avoid sampling data around data transitions of the first clock domain data. The count value can also be used to select an edge of the second clock signal to use for sampling the first clock domain data to ensure first clock domain data is not sampled during data transitions.

Methods and systems are described for receiving a plurality of signals corresponding to symbols of a codeword on a plurality of wires of a multi-wire bus, and responsively generating a plurality of sub-channel outputs using a plurality of multi-input comparators (MICs) connected to the plurality of wires of the multi-wire bus, generating a plurality of wire-specific skew control signals, each wire-specific skew control signal of the plurality of wire-specific skew control signals generated by combining (i) one or more sub-channel specific skew measurement signals associated with corresponding sub-channel outputs undergoing a transition and (ii) a corresponding wire-specific transition delta, and providing the plurality of wire-specific skew control signals to respective wire-skew control elements to adjust wire-specific skew.

The invention discloses a DDR (Double Data Rate) time sequence and delay skew simulation evaluation method based on a lookup table. The time sequence simulation evaluation method comprises the following steps: step 1), performing time sequence simulation in advance on signal lines of various signal transmission component types and delay physical property types, and obtaining a unit length delay lookup table of the signal lines; step 2), dividing signal lines of signals to be analyzed into signal line sub segments, and determining the delay physical property type and line length of each signal line sub segment; step 3), obtaining the signal delay of each signal line sub segment by the lookup table; and step 4), summarizing the delays of various signal line sub segments and obtaining a total delay of the signals to be analyzed; the delay skew simulation evaluation method subtracts the total delay of two signals to be analyzed and calculates the delay skews of the two signals to be analyzed. The DDR time sequence and delay skew simulation evaluation method based on the lookup table provided by the invention can simply and quickly perform simulation evaluation on the DDR signal delay and skew, and provide fast and accurate time sequence evaluation and design reference for the DDR signal design in view of the influences of different signal transmission components and delay physical properties.

Methods and systems are described for sequentially obtaining a plurality of data streams, the plurality of data streams comprising a data stream in a current condition, a data stream in a skewed-forward condition, and a data stream in a skewed-backward condition, calculating, for each data stream in the plurality of data streams, a corresponding set of cost-function values by obtaining a corresponding set of eye measurements, the eye measurements obtained by adjusting a sampling threshold of a sampler generating a plurality of samples of the data stream, the plurality of samples comprising edge samples and data samples, wherein the data stream is sampled at a rate equal to twice a rate of the data stream and calculating the corresponding set of cost-function values based on the corresponding set of eye measurements, and generating a skew control signal based on a comparison of the sets of calculated cost-function values.

A system for a backplane that employs i) an adjustment of positive-to-negative (P-N) driver skew of a transmit signal of a relatively high-speed differential driver to reduce far-end crosstalk, ii) a high-speed differential subtraction circuit combining a gain-adjusted replica of at least one transmit signal with a received signal to reduce near-end crosstalk, and iii) a phase-locked loop (PLL) synchronization circuit to align timing events between a set of near-end and far-end high-speed interfaces.

An apparatus for determining the amount of skew to be injected into a high-speed data communications system of including a plurality of lanes having a data bus per lane, relative to a reference lane, for system skew compensation. By knowing the relative amount of skew that each lane requires for alignment, an appropriate amount of skew can be injected on each lane to provide alignment and thus compliancy with the SFI-5 and SxI-5 standards, in terms of data skew specifications. The relative skew amounts for each transmitting lane are determined using a methodology involving internal loopback and characteristics from a connected communications element to the chip receive path.

The invention relates to a tri-mode probe with automatic skew adjustment. A probe, including a first input configured to receive a first input signal, a second input configured to receive a second input signal, a first cable connected to the first input, a second cable connected to the second input, an electronically adjustable delay connected to the first cable, the electronically adjustable delay configured to delay the first input signal to remove a skew between the first input signal and the second input signal, and an amplifier configured to receive the first input signal from the electronically adjustable delay and a second input signal.

A system and method are provided for calibrating temporal skew in a multichannel optical transport network (OTN) transmission device. The method accepts a pair of 2n-phase shift keying (2n-PSK) modulated signals, as well as a pair of 2p-PSK modulated signals. The 2n-PSK and 2p-PSK signals are converted to 2n-PSK and 2p-PSK optical signals, respectively. The 2n-PSK and 2p-PSK optical signals are orthogonally polarized and transmitted. A timing voltage is generated that is responsive to the intensity of the orthogonally polarized signals. The timing voltage is correlated to a reference frame calibration pattern associated with a preamble / header portion of an OTN frame. Then, the timing voltages associated with the Ix, Qx, Iy, and Qy signal paths are compared, and the misalignment between the timing voltages and the reference frame calibration pattern is minimized in response to adjusting time delay modules in the Ix, Qx, Iy, and Qy signal paths.

An analog to digital converter (ADC) device includes ADC circuitries, a calibration circuitry, and a skew adjustment circuitry. The ADC circuitries are configured to convert an input signal according to interleaved clock signals, in order to generate first quantization outputs. The calibration circuitry is configured to perform at least one calibration operation according to the first quantization outputs, in order to generate second quantization outputs. The skew adjustment circuitry is configured to determine maximum value signals, to which the second quantization outputs respectively correspond during a predetermined interval, and to average the maximum value signals to generate a reference signal, and to compare the reference signal with each of the maximum value signals to generate adjustment signals, in order to reduce a clock skew of the ADC circuitries.

Methods and systems are described for sequentially obtaining a plurality of data streams, the plurality of data streams comprising a data stream in a current condition, a data stream in a skewed-forward condition, and a data stream in a skewed-backward condition, calculating, for each data stream in the plurality of data streams, a corresponding set of cost-function values by obtaining a corresponding set of eye measurements, the eye measurements obtained by adjusting a sampling threshold of a sampler generating a plurality of samples of the data stream, the plurality of samples comprising edge samples and data samples, wherein the data stream is sampled at a rate equal to twice a rate of the data stream and calculating the corresponding set of cost-function values based on the corresponding set of eye measurements, and generating a skew control signal based on a comparison of the sets of calculated cost-function values.

A data handoff controller includes a counter coupled to supply a count value indicative of a skew between a first clock signal and a second clock signal. The first and second clock signal have a fundamental beat frequency. A greatest common factor circuit is used to determine the fundamental beat frequency and the second is reset based on the beat frequency. A sampling circuit samples first clock domain data with the second clock signal. The sampling circuit is controlled to sample, at least in part, based on the count value. The count value can be used to impose a blackout window in which data is not sampled to avoid sampling data around data transitions of the first clock domain data. The count value can also be used to select an edge of the second clock signal to use for sampling the first clock domain data to ensure first clock domain data is not sampled during data transitions.

A deskew system includes a first voltage control delay receiving a data signal and generating N-numbered delayed data signals obtained by delaying a phase of the data signal in units of 90 / N, where N is a natural number that is not less than 1. In response to a phase control signal, a second voltage control delay receives a clock and generates N-numbered delayed clocks by delaying a phase of the clock in units of 90 / N. A skew compensation control unit generates a plurality of skew control signals to compensate for skew between the data signal and the clock based on the data signal, the N-numbered delayed data signals, the clock, and the N-numbered delayed clocks.

The present invention relates to a method and an apparatus for automatic skew compensation. The apparatus according to the present invention comprises: a skew compensating part configured to receive a high speed data signal and output a plurality of delay data signals having different delay times; a start code detecting part configured to detect a start code from the plurality of delay data signals; and a control part configured to determine a skew delay time depending on signal reception quality which is determined on the basis of the number of start codes normally detected for each different delay time. The apparatus may further comprise a packet start detecting part configured to receive an LP signal separated from an MIPI D-PHY and count the number of received packets. The packet start detecting part receives the LP signal separated from the MIPI D-PHY, and counts the number of packets received at every preset quality evaluation time by detecting the start location of a packet according to the state of the LP signal. The signal reception quality is obtained using the number of normally detected start codes and the number of received packets received and counted at every quality evaluation time. The present invention can automatically compensate the skew between a data signal and a clock signal in an MIPI D-PHY reception system.