Abstract: A timing lock detection apparatus and method for digital broadcasting receiver are provided. The apparatus includes: a discrete value generator for cyclically selecting a discrete signal value from a continuous timing error signal; a differential calculator for obtaining a difference between the currently selected timing error signal value and a previously selected timing error signal that is a timing jitter signal; a sign variation detector for detecting variation in a sign of the timing jitter signal; a lock control signal generator for discriminating a period based on the detected sign changing time, and controlling a lock step of the loop filter according to a convergence mode of the timing jitter signal at each period; and a lock detection signal generator for generating a lock signal or an unlock signal according to whether the timing jitter signal reaches a steady state and using the current lock step signal.

Abstract: The present invention recognises and eliminates from a biomagnetic measurement signal interferences whose source is disposed in the direct vicinity of an object being measured. The invention utilises the SSS method that can be used to separate from one another the signals associated with the internal and external sources of a set of measurement sensors by calculating two series developments. The sources to be examined in the invention and disposed in the so-called intermediate space produce a component to both of the developments, and can, therefore, be detected by means of an analysis to be performed in a time domain. This division into components can be made using the Principal Component Analysis (PCA), the Independent Component Analysis (ICA) or the Singular Value Decomposition. Finally, the clarified interferences in the intermediate space can be eliminated from the measured signal using, for example, the linear algebraic orthogonal projection.

Abstract: A system and circuit for determining data signal jitter via asynchronous sampling provides a low cost and production-integrable mechanism for measuring data signal jitter. The data signal is edge-detected and sampled by a sampling clock of unrelated frequency the sampled values are collected in a histogram according to a folding of the samples around a timebase. The timebase is determined by sweeping to detect a minimum jitter for the folded data. The histogram for the correct estimated timebase period is representative of the probability density function of the location of data signal edges and the jitter characteristics are determined by the width and shape of the density function peaks. Frequency drift can be corrected by adjusting the timebase used to fold the data across the sample set.

Abstract: A circuit for detecting noise events in a system with time variable operating points is provided. A first voltage, which is averaged over time, is compared to a second voltage. A signal is generated to instruct circuits within a processor to initiate actions to keep a voltage from drooping further.

Abstract: Delay-fault testing and parametric analysis systems and methods utilizing one or more variable delay time-base generators. In embodiments of the delay-fault testing systems, short-delay logic paths are provided with additional scan-chain memory elements and logic that, in conjunction with the one or more variable-delay time-base generators, provides the effect of over-clocking without the need to over-clock. Related methods provide such effective over-clocking. In embodiments of parametric analysis systems, test point sampling elements and analysis circuitry are clocked as a function of the output of the one or more variable-delay time-base generators to provide various parametric analysis functionality. Related methods address this functionality.

Abstract: Methods and apparatuses for reducing the response time along with increasing the probability of ranging of optical rangefinders that digitize the signal waveforms obtained from the pulse echoes returned from various types of objects to be ranged, the pulse echoes being too weak to allow successful ranging from a single waveform or the objects being possibly in motion during the capture of the pulse echoes. In a first embodiment of the invention, the response time at close range of a digital optical rangefinder is reduced by using a signal averaging process wherein the number of data to be averaged varies with the distance according to a predetermined function. In a second embodiment of the invention, the probability of ranging objects in motion along the line of sight of a digital optical rangefinder is increased and the object velocity measured by performing a range shift of each acquired signal waveform prior to averaging.

Abstract: A system for estimating bit error rates (BER) may include using a normalization factor that scales a BER to substantially normalize a Q-scale for a distribution under analysis. A normalization factor may be selected, for example, to provide a best linear fit for both right and left sides of a cumulative distribution function (CDF). In some examples, the normalized Q-scale algorithm may identify means and probabilistic amplitude(s) of Gaussian jitter contributors in the dominant extreme behavior on both sides of the distribution. For such contributors, means may be obtained from intercepts of both sides of the CDF(Qnorm(BER) with the Q(BER)=0 axis, standard deviations (sigmas) may be obtained from reciprocals of slopes of best linear fits, and amplitudes may be obtained directly from the normalization factors. In an illustrative example, a normalized Q-scale algorithm may be used to accurately predict bit error rates for sampled repeating or non-repeating data patterns.

Abstract: A method and apparatus for anti-islanding of distributed power generation systems having an inverter comprising a phase locked loop (PLL), a phase shift generator for injecting a phase shift into the PLL during at least one sample period, and a phase error signature monitor for monitoring at least one phase error response of the PLL during the at least one sample period.

Abstract: A system for determining signal-to-noise ratio (SNR), signal-to-noise and distortion ratio (SINAD), and total harmonic distortion (THD), includes logic for estimating a frequency of a dominant sinusoidal signal present in a sampled data record, logic for iteratively fitting a curve, the curve including a fundamental sinusoid, harmonic components and a DC offset, and logic for computing SNR, SINAD and THD using the fundamental sinusoid, harmonic components and a DC offset.

Abstract: Methods and apparatuses for reducing the response time along with increasing the probability of ranging of optical rangefinders that digitize the signal waveforms obtained from the pulse echoes returned from various types of objects to be ranged, the pulse echoes being too weak to allow successful ranging from a single waveform or the objects being possibly in motion during the capture of the pulse echoes. In a first embodiment of the invention, the response time at close range of a digital optical rangefinder is reduced by using a signal averaging process wherein the number of data to be averaged varies with the distance according to a predetermined function. In a second embodiment of the invention, the probability of ranging objects in motion along the line of sight of a digital optical rangefinder is increased and the object velocity measured by performing a range shift of each acquired signal waveform prior to averaging.

Abstract: A path of a signal extends from an initial point through first and second cells to an end point. The signal is supplied as a first signal to the first cell and outputted therefrom as a second signal. The signal is supplied as a third signal to the second cell and outputted therefrom as a fourth signal. First delay amounts of the signal in the first cell and a transition time of the second signal are calculated based on a transition time of the first signal and a voltage supplied to the first cell. Second delay amounts of the signal in the second cell and a transition time of the fourth signal are calculated similarly. Here, the transition time of the second signal is set to be a transition time of the third signal. Jitter values in the end point are calculated based on the first and second amounts.

Abstract: An approach is provided for measuring, identifying, and removing at least one sinusoidal interference signal (Ak·ej(?kt+?k), Ak·ej(?·?k?t+?k)) in a noise signal (w(t), w(?·?t)). A frequency range to be measured is split into a plurality of frequency bands (?) via a Fast Fourier Transform (FFT) filter bank. For each of the frequency bands (?), an autocorrelation matrix ({circumflex over (R)}?) is determined, wherein parameters of the autocorrelation matrices ({circumflex over (R)}?) are variably adjusted based on whether the at least one sinusoidal interference signal (Ak·ej(?kt+?k), Ak·ej(?·?k?t+?k)) is to be measured, identified, or removed and further based on at least one averaging. The autocorrelation matrices ({circumflex over (R)}?) are jointly utilized for one or more of measuring, identifying, or removing the at least one sinusoidal interference signal (Ak·ej(?kt+?k), Ak·ej(?·?k?t+?k)) in the noise signal (w(t), w(?·?t)).

Abstract: The invention proposes a method of processing a noisy digital time signal yk corresponding to an initial time signal xt after having been conditioned by a conditioning chain, the said initial signal xt representing information about radiations coming from a radiation source, these radiations having an energy distribution, characterised in that a state model is implemented, representing the conditioning imposed by the said chain to pass from the initial time signal xt to the noisy digital time signal yk in order to obtain from the noisy digital time signal yk a non-noisy digital estimate signal of the initial time signal xt. The invention furthermore proposes a system capable of implementing said method.

Abstract: Relative noise is a single scalar value that is used to predict the maximum value of the expected noise at any point and is calculated from the measured signal and a mathematical noise model. The mathematical noise model is selected or estimated from an observation that includes statistical and/or numerical modeling based on a population of measurement points. An absolute noise for a plurality of points of the measured signal is estimated. An array of values is calculated by dividing each of a plurality of points of the absolute noise by a corresponding expected noise value calculated from the mathematical noise model. The relative noise is calculated by taking a standard deviation of a plurality of points of the array. The relative noise can be used to calculate scaled background signal noise, filter regions, denoise data, detect false positives from features, calculate S/N, and determine a stop condition for acquiring data.

Abstract: An approach is provided for digital triggering a recording of one or more digitized signals on a digital oscilloscope by means of carrying out a level comparison for determining a triggering instant in each case between two successive sample values of a reference signal and a threshold values. According to the approach, at least one additional sample value of the reference signal is determined between two sequential samples of the reference signals by means of interpolation.

Abstract: In a particular embodiment, a method is disclosed that estimates a total static noise margin of a bit cell of a memory. The method includes determining a correlation coefficient of a left static noise margin of the bit cell as compared to a right static noise margin of the bit cell and estimating a total static noise margin of the bit cell by evaluating an analytical function based on the correlation coefficient.

Abstract: A measuring apparatus measures a signal-under-test having a signal level that changes at predetermined bit time intervals. A strobe timing generator sequentially generates strobes at even time intervals. A level comparator detects a level of the signal at a timing at which each strobe is sequentially provided. A capture memory stores a signal level output from the comparator. A signal processor calculates a measurement of the signal based on a data series including data taken at even time intervals, each larger than a bit time interval of the signal.

Abstract: In one embodiment, distortion in a received speech signal is estimated using at least one model trained based on subjective quality assessment data. A speech quality assessment for the received speech signal is then determined based on the estimated distortion.

Abstract: Embodiments of the invention are related to managing noise in sensed signals in implantable medical devices, amongst other things. In an embodiment the invention includes a method for processing electrical signals obtained from a patient including gathering a first set of electrical signals using an implantable medical device, filtering to provide a second set of electrical signals, the second set including frequencies above a threshold frequency, and estimating the amount of noise present in the first set of electrical signals based on the magnitude of the second set. In an embodiment, the invention includes a medical device configured to gather a first set of electrical signals, filter the first set to provide a second set of electrical signals including frequencies above a threshold frequency, and estimate the amount of noise present in the first set based on the magnitude of the second set. Other embodiments are also included herein.

Abstract: Provided is a signal output control section that inputs to a digitizer a reference signal whose frequency changes at each prescribed measurement cycle; a data extracting section that extracts a number of pieces of data corresponding to an integer multiple of a period of the reference signal in each measurement cycle, from pieces of data of a reference digital signal output by the digitizer according to the reference signal that come after a prescribed wait interval has passed since an initiation timing of each measurement cycle; a distortion identifying section that calculates the non-linear distortion caused by the digitizer for each frequency of the reference signal, based on the data in each measurement cycle extracted by the data extracting section; and a distortion calculating section that calculates the non-linear distortion caused by the digitizer when the analog signal input to the digitizer has a frequency that differs from any of the plurality of frequencies at which the reference signal transitions

Abstract: Provided is a jitter injection circuit that generates a jittery signal including jitter, including a plurality of delay circuits that receive a supplied reference signal in parallel and that each delay the received reference signal by a preset delay amount and a signal generating section that generates each edge of the jittery signal according to a timing of the signal output by each delay circuit. In the jitter injection circuit the delay amount of at least one delay circuit is set to be a value different from an integer multiple of an average period of the jittery signal.

Abstract: Disclosed is an apparatus for generating a stable clock signal having a Long term jitter noise removed therefrom. In a mobile communication terminal having a power management chip for converting a sinusoidal wave oscillated in a crystal into a clock signal of square wave, the sinusoidal wave is converted into a square wave clock signal by the stabilized driving power having no alternating current components, and thus a power noise of the square wave clock signal is removed. Then, the square wave clock signal having the power noise removed therefrom is outputted after a predetermined delay time. Accordingly, it is possible to supply the clock signal having the Long term jitter noise removed therefrom and synchronized to each device in the mobile communication terminal.

Abstract: A method of testing input signals coupled to a circuit for performing a predetermined function is disclosed. The method comprises coupling input signals to inputs of the circuit by way of programmable interconnects; controlling the paths of the input signals within the circuit from the inputs to an output of the circuit; maintaining the states of the input signals coupled to the inputs of the circuit and routed to the output of the circuit; and testing output signals of the circuit to determine whether the correct input signals were provided to the inputs of the circuit by way of the programmable interconnects. A device having programmable logic which enables testing of input signals is also disclosed.

Abstract: Systems and methods are presented for measuring power levels of primary and interfering signals as well as noise, particularly for satellite transmitted signals. A typical method comprises the steps of receiving a signal comprising a primary signal, an interference signal and noise, demodulating the primary signal to remove a carrier frequency, decoding the primary signal to obtain symbols, estimating a power level of the primary signal based upon the demodulated and decoded primary signal. Additionally, an ideal primary signal can be generated from the carrier power and frequency and the symbols and subtracted from the received signal to produce the noise and interference signal. The noise and interference power is then estimated from the noise and interference signal.

Abstract: A method of and a system for detecting a person occupying a vehicle seat or a corresponding underlay whereby the underlay is provided with a single dynamic sensor and whereby the measurement signal is compared with a reference signal in comparing means, wherein the system comprises first measuring means for measuring a first measurement signal in a first frequency band representing a signal for human presence, and second measuring means for measuring the reference signal as a second measurement signal in a second frequency band representing a signal for background noise, comparing means for indicating an occupancy, wherein the signal strength in the first measurement signal in the first frequency band of human presence signal domination is compared to the signal strength in the reference signal in the second frequency band where essentially only background noise exists.

Abstract: There is provided a probability density function separating apparatus that separates a predetermined component in a given probability density function. The probability density function separating apparatus includes a domain transforming section that is supplied with the probability density function and transforms the probability density function into a spectrum in a frequency domain, and a deterministic component computing section that multiplies a multiplier coefficient according to a type of distribution of a deterministic component included in the given probability density function by a first null frequency of the spectrum in the frequency domain and computes a peak to peak value of the probability density function with the deterministic component.

Abstract: The present invention relates to verification of a transmission margin of various transmission lines transmitting a signal such as a high-speed digital signal and ensures improved verification accuracy. A transmission margin verification apparatus according to the present invention is configured with a measurement unit (e.g., LSI tester 4, network analyzer 6, pulse generator 8, oscilloscope 10) operable to measure a transmission loss and a leading edge waveform of pseudo transmission lines (e.g., transmission lines 56, 62, 66) corresponding to a target device 44 to be verified, and a calculation unit (tester controller 12) operable to reference the transmission line loss and the leading edge waveform measured by the measurement unit, calculate a transmission waveform of the target device, and associate the transmission waveform with a mask of the target device to calculate a transmission margin of the target device.

Abstract: Apparatus and method for increasing the sensitivity in the detection of optical coherence tomography and low coherence interferometry (“LCI”) signals by detecting a parallel set of spectral bands, each band being a unique combination of optical frequencies. The LCI broad bandwidth source is split into N spectral bands. The N spectral bands are individually detected and processed to provide an increase in the signal-to-noise ratio by a factor of N. Each spectral band is detected by a separate photo detector and amplified. For each spectral band the signal is band pass filtered around the signal band by analog electronics and digitized, or, alternatively, the signal may be digitized and band pass filtered in software. As a consequence, the shot noise contribution to the signal is reduced by a factor equal to the number of spectral bands. The signal remains the same. The reduction of the shot noise increases the dynamic range and sensitivity of the system.

Abstract: A system and circuit for constructing a synchronous signal diagram from asynchronous sampled data provides a low cost and production-integrable technique for providing a signal diagram. The data signal is edge-detected and asynchronously sampled (or alternatively a clock signal is latched). The data signal or a second signal is compared to a settable threshold voltage and sampled. The edge and comparison data are folded according to a swept timebase to find a minimum jitter period. The crossing of the signal diagram edges is determined from a peak of a histogram of the folded edge data. A histogram of ratios of the sample values versus displacement from the position of the crossing location is generated for each threshold voltage. The technique is repeated over a range of settable threshold voltages. Then, the ratio counts are differentiated across the histograms with respect to threshold voltage, from which a signal diagram is populated.

Abstract: Noise discrimination in signals from a plurality of sensors is conducted by enhancing the phase difference in the signals such that off-axis pick-up is suppressed while on-axis pick-up is enhanced. Alternatively, attenuation/expansion are applied to the signals in a phase difference dependent manner, consistent with suppression of off-axis pick-up and on-axis enhancement. Nulls between sensitivity lobes are widened, effectively narrowing the sensitivity lobes and improving directionality and noise discrimination.

Abstract: An apparatus, method, and computer program are provided for controller performance monitoring in a process control system. A level of disturbance associated with the process system is determined, and at least one value identifying a stability measure of a controller in the process system is determined using the determined level of disturbance and operating data associated with operation of the process system. The at least one value is compared to at least one threshold value, and a problem with the controller is identified based on the comparison. As an example, the process system could represent a product production system. Also, the operating data could include at least one of: measurement data from one or more sensors and control data for one or more actuators. The controller may be operable to receive the measurement data and generate the control data.

Abstract: Method and systems for aligning a clock at a second device based on a reference clock at a first device and reducing clock rate jitter between asynchronous devices in a network are disclosed. A transmission latency may be determined between the first device and the second device. A data packed may be received containing information pertaining to the reference clock at the second device. The phase of the clock may then be adjusted at the second device based on the information contained in the packet and the transmission latency.

Abstract: There is provided a measuring apparatus for measuring a signal-to-noise ratio of a discrete waveform which is output from an AD converter in response to an input signal, where the signal-to-noise ratio indicates a ratio of a signal component of the input signal to noise generated by the AD converter. The measuring apparatus includes a spectrum compensating section that receives a spectrum of the discrete waveform output from the AD converter, and compensates the received spectrum in accordance with a non-symmetric sideband between an upper sideband and a lower sideband of the received spectrum, where the upper and lower sidebands are defined with respect to a fundamental frequency of the input signal, and a phase noise waveform calculating section that calculates a phase noise waveform of the discrete waveform based on the spectrum which has been compensated by the spectrum compensating section.

Abstract: There is provided a jitter measuring apparatus for measuring jitter in a signal-under-measurement having a first pulse generator for detecting edges of the data-signal-under-measurement to output a first pulse signal having a pulse width set in advance corresponding to the edge, a second pulse generator for detecting boundaries of data sections where data values do not change in the data-signal-under-measurement to output a second pulse signal having a pulse width set in advance corresponding to timing of the detected boundaries of the data sections, a filter for removing carrier frequency components of said data-signal-under-measurement from first and second pulse signals and a jitter calculating section for calculating timing jitter in the data-signal-under-measurement based on the first and second pulse signals.

Abstract: A method implemented by a user equipment includes selecting a first estimate of a signal-to-noise (SNR) ratio, calculating a first amplitude and first noise variance, calculating a second amplitude and a second noise variance, calculating a second SNR, calculating a resolution value, adjusting the first SNR, and performing estimation iterations until the resolution value is equal to a predetermined value.

Abstract: Provided is an evaluation apparatus that evaluates a characteristic of a propagation apparatus propagating a signal, comprising an output signal measuring section that measures a probability density function expressing a probability density distribution of jitter of an output signal passed by the propagation apparatus; an isolating section that isolates at least one of a random component of a jitter component and a deterministic component of the jitter component in the jitter of the output signal, from the probability density function of the jitter of the output signal; and an evaluating section that evaluates the characteristic of the propagation apparatus based on the jitter component isolated by the isolating section.

Abstract: A test apparatus for testing a device under test includes a multi-strobe generating section that generates a plurality of strobe signals with different phases in each of cycles of an output signal output from the device under test, a plurality of timing comparing sections that obtain a value of the output signal respectively at timings of the plurality of strobe signals, a transition detecting section that generates transition data identifying one of the plurality of strobe signals which is positioned at a transition of the output signal, based on the values of the output signal which are respectively obtained at the timings of the plurality of strobe signals, a transition memory that sequentially stores thereon the transition data input thereto, a selecting section that selects, in association with each of the cycles of the output signal, whether to input the transition data output from the transition detecting section into the transition memory, and a calculating section that calculates jitter of the output

Abstract: A D/U ratio is measured for desired and undesired signals in a wireless video transmission system at a shared channel frequency based on a received signal at a geographic location in proximity to regions within respective service areas for the desired and undesired signals. A video tuner demodulates the received signal to generate a baseband video signal. A leveling circuit normalizes the baseband signal. A video processor identifies horizontal sync pulses within the baseband signal, generates a sampled signal comprising the horizontal sync pulses, and removes components of the desired signal from the sampled signal to generate an undesired signal component. A D/U analyzer determines a Fourier transform having a plurality of bins in response to the undesired signal component, identifies at least one of the bins having a spectral peak corresponding to an undesired signal, and calculates the D/U ratio in response to a magnitude of the identified peak.

Abstract: Time correlation of signal to distortion characteristics is achieved by acquiring time domain data for a frequency band representing a communication signal, the communication signal having multiple channels. The time domain data is simultaneously converted to frequency and demodulation domain data in sequential time blocks. The frequency and demodulation domain data are processed to obtain respectively frequency and demodulation domain measurements. The resulting measurements are displayed simultaneously as a function of time for all the time blocks and/or for a selected one of the time blocks. An ACLRogram display provides a display having a time axis and a frequency axis in the form of bars spanning the frequency band for each time block with each bar being divided into frequency sub-bands representing a main channel and adjacent side channels, the shading of each segment of the bar representing a measurement value for that segment.

Abstract: A communications connector tester for quickly and accurately analyzing communications connectors at production to determine whether the connectors are fit for use in certain communications applications is disclosed. Test signals at several discrete frequencies are sequentially inputted into pairs of conductors in the communications connector under test, and output signals are detected for the pairs under test. The output signals are compared to acceptable ranges for certain applications of the communications connector and the connector is passed or failed for certain applications based on the output signal values. Near-end crosstalk, far-end crosstalk, return loss, insertion loss, and other communications connector qualities may be measured using the present invention.

Abstract: In order to measure the phase jitter of a high-frequency signal, a spectrum analyzer is used. The high-frequency signal (HF) to be measured is either multiplied by M and/or the output frequency of the variable frequency oscillator of the spectrum analyzer is divided by N, and both signals are set to the same frequency and mixed in a mixer. The output signal of the mixer is then evaluated in the preferably digital evaluating device of the spectrum analyzer according to the Fast Fourier Transformation principle. To this end, the spectrum analyzer requires only one additional mixer, frequency divider and/or frequency multiplier.

Abstract: In some embodiments an apparatus includes a higher order statistical signal processor to process a jittered digital signal, a diagonal line average unit to identify a distinct line in a signal output from the higher order statistical signal processor, and a peak detection unit to determine a peak value in response to an output of the diagonal line average unit and to provide a data rate signal as an output. Other embodiments are described and claimed.

Abstract: A semiconductor integrated circuit includes a first power source having a power supply voltage that operates the semiconductor integrated circuit, a voltage comparator that compares the power supply voltage with a reference voltage, and a comparison result recording unit that records a comparison result of the voltage comparator, wherein the comparison result recording unit records a length of a period based on a clock signal for which the power supply voltage exceeds the reference voltage.

Abstract: Selectable portions of a display on a display screen allow a user to select bits of a digital signal. A mode selection menu changes the bit selection to select bits in different ways. If an individual bit designation mode is selected, objects are displayed that correspond to the respective bits of the digital signal. A user selects the object corresponding to a desired bit by use of a mouse. After bit selection, an eye pattern, derived from only selected bits, is displayed. Additionally, jitter analysis results derived from only the selected bits are displayed.

Abstract: A method and apparatus identifies a region of interest of transient vibration data needing analysis and provides context and construction for analytical plots. The method provides transient data, determines a region of interest of the transient data, specifies a construction mode corresponding to a derived graphical display of the transient data, and specifies one or more construction parameters corresponding to the specified construction mode. The method also processes the transient data to produce at least one derived plot based on the transient data, the region of interest, the specified construction mode, and the specified construction parameters. This method may be performed by a graphical tool having a hardware module and a software module. The hardware module including a processor, a memory, a display, and a communicator, and the software module including a plotting module and a plot control module.

Abstract: A method and apparatus that is configured to issue an echo extended link service with a payload of data patterns that are known in the art of fiber channel to produce jitter. The inventive apparatus is configured to use an echo extended link service to send data with a specified data pattern. Failing data patterns are compared against data patterns that are known in the art of fiber channel to create jitter and the results may be presented to the user.

Abstract: A jitter measurement apparatus measures a jitter of a data signal having a substantially constant data rate. The jitter measurement apparatus includes therein a signal converting section that generates a clock signal based on the data signal, where the clock signal retains timings of data transition edges of the data signal at which a data value of the data signal transits and has edges whose cycle is substantially equal to the data rate, an analytic signal generating section that generates an analytic signal represented by a complex number based on the clock signal, and a jitter measuring section that measures the jitter of the data signal based on the analytic signal.

Abstract: Systems and methods for synchronizing communication between devices include using a test circuit to measure a propagation time through a delay circuit. The propagation time is used to determine an initial delay value within a delay lock loop. This delay value is then changed until a preferred delay value, resulting in synchronization, is found. In various embodiments, used of the initial delay value increases the speed, reliability or other beneficial features of the synchronization.

Abstract: Coded test signals in two or more distinct coding formats are applied sequentially to the equipment under test (EUT) according to a test sequence. The ordering, timing and source characteristics of the coded test signals are fully programmable. The output of the EUT is analyzed to verify proper decoding and detect audible artifacts. A means for comparing recorded test events allows a test engineer to detect failure modes of the autodetection system in the EUT.

Abstract: A data communication system includes circuitry to assure components respond to variations in the time length of the valid data window or “eye” of the high speed data communication signal. A self-test portion of the system periodically injects the effects of phase jitter into the data communication signal to assure the system performs properly.