Abstract: In a preferred embodiment, the invention provides a circuit for reducing bit error rates. A data recovery circuit recovers data from a first HSS link to differential bit pair inputs. Data from the differential bit pair outputs of the data recovery circuit drive differential bit pair inputs to a plurality of FIFOs. The data is then driven from a parallel output of the plurality of FIFOs to the parallel input of a synchronizer. The data is then driven from the parallel output of the synchronizer to the parallel input of a serializer. The serializer, through different bit pair outputs, drives a second serial HSS link.

Abstract: The present invention relates to a detector arrangement and a charge pump circuit for a recovery circuit recovering timing information for random data. The detector arrangement comprises first latch means for sampling a quadrature component of a reference signal based on an input signal, to generate a first binary signal, a second latch means for sampling an in-phase component of the reference signal based on the input signal, to generate a second binary signal, and a third latch means for sampling the first binary signal based on the second binary signal, to generate a frequency error signal. Thus, a simple and fast detection circuitry can be achieved based on a digital implementation. Furthermore, the charge pump circuit comprises a differential input circuit and control means for controlling a tail current of the differential input circuit in response to a frequency-locked state of frequency detector arrangement.

Abstract: A method for the compensation of frequency-response mismatch errors in M-channel time-interleaved ADCs. The compensation is done utilizing a technique that makes use of a number of fixed filters, that approximate differentiators of different orders, and a few variable multipliers that directly correspond to parameters in polynomial models of the M channel frequency responses. A compensated M-channel time-interleaved ADC is based on and can perform the method.

Abstract: One embodiment of the invention is a portion of a test system that includes a timing generation circuit and a formatter that are coupled together, which are on a single CMOS (complementary metal oxide semiconductor) integrated circuit. The timing Generation circuit generates software words. The formatter receives the software words and provides a specified number of transitions per second and a specified edge placement resolution and accuracy. It is noted that the formatter includes a drive circuit and a response circuit. Specifically, the drive circuit includes a plurality of slices, where each slice receives an independent data stream and produces an independent formatted level. The response circuit includes a plurality of slices, where each slice receives an independent data stream and produces an independent strobe marker.

Abstract: Methods and apparatus provide for: a plurality of stages of combinational logic, each stage including a full latch circuit operable to transfer data into the given stage of combinational logic and a transparent latch circuit operable transfer output data from the given stage of combinational logic to a next of the stages; in each stage, passing state changes of output data from the given combinational logic irrespective of when such changes occur when a clock signal of the transparent latch circuit is at a first of two logic levels; and in each stage, withholding state changes of the output data until the clock signal of the transparent latch circuit transitions from the second of the two logic levels to the first logic level.

Abstract: An apparatus and method for reducing false triggering of a signal due to an electrostatic discharge event are disclosed. The method includes detecting a high voltage on a signal received at an input of a delay circuit and delaying the signal between the input of the delay circuit and an output of the delay circuit for a predetermined amount of time. If a low voltage is detected on the signal after the predetermined amount of time, the high voltage is prevented from propagating to the output of the delay circuit.

Abstract: In a circuit and method for correcting skew among a plurality of communication channels used in communicating with a memory circuit, and in a memory controller and memory controlling method, and in a memory system and method, the circuit for correcting skew includes a transmitting circuit for transmitting a reference signal to input ends of the plurality of channels and through the plurality of channels, and a plurality of receiving circuits for receiving at the input ends of the plurality of channels a respective plurality of reflected signals, the reflected signals being reflected from respective output ends of the plurality of channels. A detection circuit receives the reflected signals and detects relative signal propagation time differences between the plurality of channels. A delay circuit coupled to at least one of the channels sets a signal propagation delay in the at least one of the channels based on the detected relative signal propagation time differences.

Abstract: The present invention relates to a substrate testing circuit comprising a testing bus and a testing signal terminal connected to the testing bus, a signal line to be tested in the substrate being connected to the testing bus via a signal connecting terminal, wherein a plurality of signal access terminals are provided on the testing bus; one testing branch is connected between each the signal access terminal and the testing signal terminal; and resistance values of the testing branches are the same.

Abstract: A method and apparatus for synchronizing plural test devices coupled to a host. A counter of each of the devices is initialized, and each of the counters is incremented, such as by a periodic signal indicating a start of a data stream. An action, typically either a source signal or a measurement signal, is triggered when a respective counter reaches a programmed counter value.

Abstract: In a receiver, a skew detector detects a skew between two synchronization symbols having different wavelengths among synchronization symbols included in received signals. A skew rough adjustment calculator calculates a delay compensation amount for each received signal based on the skew and a signal delay characteristic in a transmission path. A variable delay processor deskews the received signals based on the delay compensation amount.

Abstract: In a digital PLL system, instead of measuring a binarized playback RF signal with a high frequency clock, pulse-length data is generated by using N phase clocks (for example, 16 phase clocks). The pulse-length data is then counted with a virtual channel clock so as to extract run-length data. In this digital PLL system, the number of changing points of an asynchronous signal during an interval between adjacent clocks of the N phase clocks is detected so as to determine phase errors from the detected number of changing points. Phase errors are also determined from the timing relationship between changing points of a signal synchronized with the N phase clocks and each clock of the N phase clocks.

Abstract: A semiconductor integrated circuit that self-tests the skew margin of the clock and data signals in an LVDS. A clock signal CKB1 is held in flip-flop circuit 105 synchronously with checking clock signal A1. Checking pattern signal PAT_A is held in flip-flop circuit 104 synchronously with checking clock signal A2. When the skew margin of clock signal CKA_IN and data signal DA_IN are checked, the checking signal TCKA of flip-flop circuit 105 is input instead of clock signal CKA_IN, and the checking signal TDA of flip-flop circuit 104 is input instead of clock signal DA_IN. The timing relationship between clock signal CKB7 and checking timing signal A1 and the timing relationship between clock signal CKB7 and checking timing signal A2 are controlled independently by timing control circuit 109.

Abstract: A dummy wiring 25 is provided for simulating an actual wiring 26 connecting semiconductor integrated circuits 2 and 6 on a circuit board. The semiconductor integrated circuit comprises a data output circuit 28 capable of variably setting the slew rate and a circuit 29 for measuring signal delay time between a signal sending point and a signal reflection point (characteristic impedance mismatching point) using the dummy wiring 25, and the delay time so obtained by the measuring circuit is used for the determination of the signal transition time of the output circuit. The transition time of the signal is set at least twice of the signal delay time between the signal sending point and the wiring branch at the nearest end. In this way, signal transmission with alleviated reflection by the reflection point at the nearest end is realized.

Abstract: A synchronous semiconductor memory device including a data alignment reference pulse generating unit configured to generate a data alignment reference pulse in response to a data strobe signal (DQS), an alignment hold signal generating unit configured to generate an alignment hold signal, which is activated during a period corresponding to a postamble of the data strobe signal, in response to the data alignment reference pulse and a data input clock, and a data alignment unit configured to align input data in response to the data alignment reference pulse and the alignment hold signal.

Abstract: In a proximity communication system, transmit elements on one chip are aligned with receive elements on a second chip juxtaposed with the first chip. However, if the elements are misaligned, either statically or dynamically, the coupling between chips is degraded. The misalignment may be compensated by controllably degrading performance of the system. For example, the transmit signal strength may be increased. The bit period or the time period for biasing each bit may be increased, thereby decreasing the bandwidth. Multiple coupling elements, such as capacitors, may be ganged together, thereby decreasing the number of channels. The granularity of symbols, such as images, may be increased by decreasing the number of bits per symbol. Multiple coupling elements, such as capacitors, may be ganged together, thereby decreasing the number of channels.

Abstract: Circuits, methods and apparatus are provided to reduce skew among signals being provided or transmitted by a data interface. Signal path delays are varied such that signals transmitted by a memory interface are calibrated or aligned with each other along a rising and/or falling edge. For example, self-calibration, external circuitry, or design tools can provide skew adjustment of each output channel by determining one or more delays for each output channel path. When aligning multiple edges, the edges of the output signals may be aligned independently, e.g., using edge specific delay elements.

Abstract: The present invention provides a method and apparatus for correcting symbol timing of a receiver. The receiver receives a signal transmitted by a transmitter based on a symbol period. The method includes: sampling the signal with a sampling period to generate N sampled data in series, wherein the sampling period is half the symbol period; from Kth data of the N sampled data, getting M data to serve as a first data set; performing a timing recovery algorithm upon the first data set to generate a first timing metric; from (Kth+1) data of the N sampled data, getting M data to serve as a second data set; performing the timing recovery algorithm upon the second data set to generate a second timing metric; and correcting the symbol timing according to the first and second timing metrics.

Abstract: Disclosed is a method for monitoring an internal control signal of a memory device and an apparatus therefore. The method includes (a) generating a first signal having a first pulse width by a burst operation command, (b) receiving the first signal, and generating N?1 (where, N is a burst length) second signals having a second pulse width, (c) receiving the first signal and the second signals, and outputting a third signal by changing the first pulse width of the first signal and the second pulse width of the second signals in accordance with a variation of a frequency of a clock signal of the memory device, (d) outputting the third signal to an external pin of the memory device and monitoring the third signal, and (e) adjusting a pulse width of a signal that controls an operation of a data bus connecting a bit-line sense amplifier and a data sense amplifier using the third signal.

Abstract: An apparatus and method for processing a captured image and, more particularly, for processing a captured image comprising a document. In one embodiment, an apparatus comprising a camera to capture documents is described. In another embodiment, a method for processing a captured image that includes a document comprises the steps of distinguishing an imaged document from its background, adjusting the captured image to reduce distortions created from use of a camera and properly orienting the document is described.

Abstract: In a method for data transmission, which transmits data through a transmission line, which integrates a plurality of links into one transmission line, a first link group, which transmits information data by at least one link out of a plurality of links, a second link group, which transmits parity data generated by the information data by at least one link out of a plurality of links, which are different from the first link group, and a third link group, which generates an error check data related to an error correction from the information data or the parity data, when an error occurs in the information data or the parity data, and transmits by at least one link out of a plurality of links, which are different from the first link group and the second link group, are integrated and transmitted.

Abstract: A semiconductor integrated circuit includes: an input/output cell that is included in a path captured during propagation delay testing and that has an output-stage buffer on an output bus; and a terminal connected to the output bus and an input bus of the input/output cell. An external load or a testing device is connectable to the terminal. The input/output cell has a switching part that is capable of switching between a first path that loops back at an output side of the output-stage buffer and a second path that loops back at an input side of the output-stage buffer. The first path is selected during normal operation and the second path is selected during the propagation delay testing.

Abstract: A method for controlling a variable of a switching electrical circuit detects values for each of a first waveform and of a second waveform in the switching circuit at a beginning of and at a predetermined instant during a switching interval of a switching operation of the electrical circuit, both of the first and second waveforms are perturbed by the switching operation, and evaluates the variable based on the corresponding values of both the first waveform and the second waveform detected at the beginning and at the predetermined instant during the switching interval. The method further adjusts an operating point of the circuit based on a change in the variable between the two evaluations so as to maximize the variable.

Abstract: Signal-integrity measurement systems and methods utilizing unique time-base generation techniques for controlling the sampling of one or more signals under test. A time-base generator made in accordance with the present disclosure includes a phase filter and modulation circuitry that generates a rapidly varying phase signal as a function of the output of a sigma-delta modulator. The phase filter filters unwanted high-frequency phase components from the rapidly varying phase signal. The filtered signal is used to clock one or more samplers so as to create sampling instances of the signal(s) under test. The sampling instances are then analyze using any one or more of a variety of techniques suited to the type of signal(s) under test.

Abstract: Systems, controllers and methods are disclosed, such as an initialization system including a controller that receives patterns of read data coupled from a memory device through a plurality of read data lanes. The controller is operable to detect any lane-to-lane skew in the patterns of read data received through the read data lanes. The controller then adjusts the manner in which the read data received through the read data lanes during normal operation are divided into frames. The controller can also couple patterns of command/address bits to the memory device through a plurality of command/address lanes. The memory device can send the received command/address bits back to the controller through the read data lanes. The controller is operable to detect any lane-to-lane skew in the patterns of command/address bits received through the read data lanes to adjust the manner in which the command/address bits coupled through the command/address lanes during normal operation are divided into frames.

Abstract: A system and method is provided for bit eye center retraining. In general, the system samples an incoming data stream to determine where transitions in the data stream occur, selectively compares the location of the transitions to the expected locations to produce difference values, and combines pairs of difference values to determine when the sample point of the data stream needs to be adjusted.

Abstract: A device has at least one integrated signal path having a measurable asymmetrical signal lag and/or jitter, an output signal of the integrated signal path being able to be decoupled in a first measuring operating mode using a controllable integrated multiplexer to measure an asymmetrical signal lag of a measuring path, which includes the integrated signal path and the integrated multiplexer, and a measuring signal being able to be decoupled in a second measuring operating mode using the controllable integrated multiplexer to measure the asymmetrical signal lag of the integrated multiplexer.

Abstract: A series of pulses may be driven down each drive channel, which creates a series of composite pulses at the output of the buffer. Each composite pulse is a composition of the individual pulses driven down the drive channels. Timing offsets associated with the drive channels may be adjusted until the individual pulses of the composite pulse align or closely align. Those timing offsets calibrate and/or deskew the drive channels, compensating for differences in the propagation delays through the drive channels. The composite pulse may be feed back to the tester through compare channels, and offsets associated with compare signals for each compare channel may be aligned to the composite pulse, which calibrates and/or deskews the compare channels.

Abstract: A method, apparatus and computer instructions for application based tracing and for normalization of processor clocks in a symmetric multiprocessor environment. By deliberately establishing a large skew among processor clocks, it is possible to perform application based tracing by directly using the processors. In addition, the identity, time stamp, and drift information of each processor may be used to create a time library. The time library is used to adjust a measured time to execute a program or software routine. The adjusted time is a normalized time that is statistically more accurate than the measured time alone. The adjusted time is then reported as the time to execute the program or software routine.

Abstract: A circuit including a first stage register that operates in response to a first clock having a period TCYCLE, a programmable delay circuit that introduces a programmable delay to the first clock, thereby creating a second clock, a second stage register that operates in response to the second clock, combinational logic coupled between the first register output and the second register input, and a third register having an input coupled to the second register output. The programmable delay is selected: (1) to have a positive value if the signal delay between the first and second registers exceeds TCYCLE, and (2) such that the signal delay between the second and third registers is less than TCYCLE minus the programmable delay. Additional delayed clocks generated in response to the second clock signal can be used to operate additional second stage registers, thereby staggering the outputs of these second stage registers within TCYCLE.

Abstract: In a high-speed serial link, an eye finder diagnostic circuit has improved performance by being on-chip with the existing capture latch(es) of a receive equalizer. The eye finder circuit employs an additional capture latch with its input tied to the same input node as the existing capture latch(es) of a receive equalizer. The additional capture latch has a clock input and reference voltage input. The clock input is adjusted through a phase interpolator (or variable delay line) while the reference voltage input is adjusted by a voltage generator. A digital post processing circuit then compares the output of the additional capture latch with the output of the other existing capture latch(es), in order to determine the receive eye opening. The horizontal eye opening is measured by changing the phase of the additional capture latch through the phase interpolator, while the vertical eye opening is measured by changing the reference voltage of the voltage generator of the additional capture latch.

Abstract: A clock pulse controller includes a test clock pulse input for receiving test clock pulses. A scan enable input receives a scan enable signal having a first state and a second state. A trigger pulse input receives a trigger pulse. A clock pulse output generates a launch clock pulse and a capture clock pulse from the test clock pulses immediately after receiving a predetermined number of the test clock pulses immediately following the trigger pulse. A delayed scan enable output generates a delayed scan enable signal that transitions from the first state to the second state between a leading edge of the launch clock pulse and a leading edge of the capture clock pulse.

Abstract: An apparatus and method for processing a data signal is provided. An acquisition unit of a test instrument acquires a data signal for a predetermined time. The data signal is stored in a memory of the test instrument and a clock recovery unit recovers a clock signal from the stored data signal. The stored data signal is sliced by a processor into a plurality of data segments of a predetermined length in accordance with the recovered clock signal.

Abstract: An integrated circuit tester channel includes an integrated circuit (IC) for adding a programmably controlled amount of jitter to a digital test signal to produce a DUT input signal having a precisely controlled jitter pattern. The IC also measures periods between selected edges of the same or different ones of the DUT output signal, the DUT input signal, and a reference clock signal. Additionally, when the DUT input and output signals convey repetitive patterns, the IC can measure the voltage of the DUT input out output signal as selected points within the pattern by comparing it to an adjustable reference voltage. Processing circuits external to the IC program the IC to provide a specified amount of jitter to the test signal, control the measurements carried out by the measurement circuit, and process measurement data to determine the amount of jitter and other characteristics of the DUT output signal, and to calibrate the jitter in the DUT input signal.

Abstract: A computer-implemented method, for application based tracing and for normalization of processor clocks in a symmetric multiprocessor environment. By deliberately establishing a large skew among processor clocks, it is possible to perform application based tracing by directly using the processors. In addition, the identity, time stamp, and drift information of each processor may be used to create a time library. The time library is used to adjust a measured time to execute a program or software routine. The adjusted time is a normalized time that is statistically more accurate than the measured time alone. The adjusted time is then reported as the time to execute the program or software routine.

Abstract: Provided are a method and an apparatus for converting an interface between high speed data having various capacities. The apparatus includes a data transmitting part and a data receiving part. The data transmitting part generates a deskew channel having respective timing data of a plurality of data transmitted from a first communicating device, and outputs the generated deskew channel together with the plurality of data to a second communicating device. The data receiving part compares the deskew channel transmitted from the second communicating device with the plurality of data to measure skew values of the data, aligns bits and bytes of the plurality of data using the skew values, and transmits the plurality of data to the first communicating device.

Abstract: Systems, controllers and methods are disclosed, such as an initialization system including a controller that receives patterns of read data coupled from a memory device through a plurality of read data lanes. The controller is operable to detect any lane-to-lane skew in the patterns of read data received through the read data lanes. The controller then adjusts the manner in which the read data received through the read data lanes during normal operation are divided into frames. The controller can also couple patterns of command/address bits to the memory device through a plurality of command/address lanes. The memory device can send the received command/address bits back to the controller through the read data lanes. The controller is operable to detect any lane-to-lane skew in the patterns of command/address bits received through the read data lanes to adjust the manner in which the command/address bits coupled through the command/address lanes during normal operation are divided into frames.

Abstract: An apparatus for testing an IC device includes a test signal generator for generating a predefined sequence of test signals that are input to the IC device. A timing skew monitor is provided for monitoring the test signals input in the IC device and a signal output from the IC device for a predetermined time period, and creating an array indicating an execution or a nonexecution of signal timing combinations of one of the test signals relative to at least one of the other test signals within the predetermined time period by the IC device. A determination as to whether the desired signal timing combinations of the test signals have been executed by the IC device is made by an operator.

Abstract: Two delay chains having in each case n series-connected unidirectional delay elements are provided for controllably delaying electrical signals between a circuit input and at least one circuit output. Each delay element is an active circuit with a fixed transit time. The input of the first delay element of the first chain is connected to the circuit input and the output of each delay element of the first delay chain is selectively connectable to the input of the (n?i+1)th delay element of the second delay chain via a respectively associated switch of a first group of switches, wherein i=1 . . . n is the ordinal number of the delay elements of the first delay chain. The output of the last delay element of the second chain is connected as a circuit output.

Abstract: The apparatus for analyzing a delay defect of the present invention obtains the RC of the maximal incidence among region codes (RCs) to which check circuits detecting errors caused with gradual increase in the frequency of an operational clock pulse fed to an integrated circuit belongs. The apparatus obtains information on latch in which an error is caused with the RC of the maximal incidence, with reference to a mapping table that describes the mapping relationship between an RC and a latch. The apparatus extracts a circuit portion in which an error can be captured with the region code of the maximal incidence by exhaustively tracing back circuit portions connected with each obtained latch, from the latch to the latch described in the mapping table. The apparatus gives delay defects to the input and the output pin of each of logic elements included in the extracted circuit portion, generates test patterns for detecting the given delay defects, and performs delay tests.

Abstract: A method of identifying and correcting each of the changes that may occur with wire pairs between the transmitter and receiver in Ethernet 10GBase-T cabling is provided. The method includes four wire pairs A, B, C and D, a polarity swapping and scrambler state machine that determine if the chosen pair matches the requirements for pair A. A slave Tap state machine generates a rule for correct B, C and D patterns based on a pair chosen as pair A. The cables B, C and D are iteratively swapped to rearrange the pair mapping into the polarity swap state machine, and a deskew state machine identifies the latency difference between the different pairs. If the rules are not satisfied, a new pair A is designated at the swapping state machine and the process is repeated until the rules are satisfied.

Abstract: A semiconductor device including an interrupt pattern generator for generating an interrupt enabling signal and interrupt data, an input buffer for receiving input serial data, a selector, receiving through-data serially output from said input buffer and serial data obtained on parallel-to-serial conversion of said interrupt data, for selecting and serially outputting said through-data when said interrupt enabling signal is in an inactive state, and for selecting and serially outputting said interrupt data when said interrupt enabling signal is in an active state, and a circuit exercising control for instructing said interrupt pattern generator to generate said interrupt data and to activate said interrupt enabling signal in case the information instructing the merging of said interrupt data in a predetermined position of said through-data is detected from said input serial data.

Abstract: There is provided a clock generator for generating a single-phase clock into which jitter has been injected, having a multi-phase clock generating section for generating a plurality of clock signals having an almost equal phase difference from each other and a jitter injecting section for injecting jitter into the respective clock signals.

Abstract: Provided are an apparatus and method for transmitting and receiving data bits. The apparatus includes a transmitter configured to generate a transmission signal corresponding to the data bits and having a periodic transition, a data line configured to transmit the generated transmission signal, and a receiver configured to generate a reception clock signal from the periodic transition of the transmission signal (“reception signal”) transmitted through the data line, sample the reception signal according to the generated reception clock signal to recover the data bits. Accordingly, it is possible to transmit clock information without a clock line separate from the data line.

Abstract: A time correcting apparatus includes a data input section which inputs all event trace data generated for each event executed on computing devices and outputs the event trace data in order of occurrence time of the event data. An inter-machine communication-time-table generating section extracts transmission and reception events from the output event trace data and generates a communication time table indicating communication times between computing devices based on the differences in occurrence time between the corresponding transmission and reception events. A time-offset deriving section generates a time offset table indicating a time offset value for each computing device based on the communication time table. A time correcting section corrects the event occurrence times of all event data based on the time offset table. A data integrating section inputs all event data whose occurrence times have been corrected and outputs the event data in order of corrected occurrence time.

Abstract: A method and apparatus for a structure of a flip-flop that is tolerant to the noise pulses occurring due to the presence of crosstalk faults by sampling the input data multiple times before and after the active clock edge. The final stored value at the flip-flop is determined by the resolution of a counter circuit residing in the flip-flop, which is activated at the change of the sampled input data. This counter based resolution mechanism allows for the detection and filtering of the noise pulse induced at the input of the flip-flop due to a crosstalk fault.

Abstract: In measuring a certain time lag between generations of two pulse signals, a time lag measuring device prevents errors in measurement results even with an error in two reference signals for measuring the time lag. The device measures a time lag between a start signal M1 and a stop signal M2 and includes a reference signal generating section 41 generating two reference signals S1, S2 having a phase difference ?/2, and an amplitude detecting section 42 detects amplitudes A11, A12 and A21, A22 of the reference signals S1, S2 at generation timings for the start signal M1 and the stop signal M2, a phase difference detecting section 43 calculating a phase _ of the reference signals S according to each set of the amplitudes (A11, A12) and (A21, A22), and a correcting section 46 correcting the calculated phase using correction data for error correction in the reference signals S1, S2.

Abstract: Methods and apparatus are provided for monitoring and compensating for skew on a high speed parallel bus. Delay skew for a plurality of signals on a parallel bus is monitored by obtaining a plurality of samples of the plurality of signals for each unit interval; and identifying a location of transitions in the plurality of signals based on the samples. The samples can be obtained, for example, by sampling the plurality of signals using a plurality of latches and estimating a value of one or more of the plurality of signals by comparing values of the latches. A microprocessor can optionally be employed to determine a relative distribution of transitions in the plurality of signals and to align transitions in the plurality of signals to a common position. The transitions in the plurality of signals can be aligned to a common position by adjusting a delay control setting for a buffer associated with each of the plurality of signals.

Abstract: A detector to detect the magnitude of the jitter that may occur in a first clock signal and a second clock signal and to generate an alarm signal if the magnitude of the jitter exceeds the threshold value. The detector comprises a one-hot register storing a one-hot value comprising a first logic bit (=1) centered around one or more second logic bits (=0). The detector comprises a threshold register storing a threshold value comprising one or more second logic bits centered around one or more first logic bits. An event of a first clock rotates the contents of the one-hot value and an event of a second clock rotates the contents of the threshold value. A match between the pre-specified bit of the one-hot value and the threshold value indicates the occurrence of the jitter having a magnitude greater than the threshold value.

Abstract: A restoration frame identifier monitoring unit checks restoration frame identifiers within split frames and carries out processing to divide inputted split frames for input to a first split frame processing circuit or a second split frame processing circuit according to the value of the frame identifier and determines whether or not the split frames are inputted within a fixed monitoring time. The split frame accumulation buffer unit repeatedly accumulates inputted split frames until a split frame for a final frame is inputted. When the split frame for the final frame is inputted, this split frame and the accumulated split frames are combined so as to generate a single restored frame. The split frame accumulation buffer unit is then cleared when the split frames are not inputted within a fixed monitoring time.

Abstract: There is provided a test apparatus that tests a device under test including a plurality of data terminals and a clock output terminal, the test apparatus including a plurality of first variable delay circuits that delays a reference clock, a plurality of timing clock generating sections that outputs a timing clock having a phase obtained by shifting a phase of the delayed reference clock by a designated phase shift amount, a timing comparator that acquires a data signal in accordance with the timing clock, a plurality of second variable delay circuits that delays the timing clock, a plurality of phase comparators that outputs a phase shift amount according to a phase difference between a clock signal and the timing clock, a first adjusting section that adjusts a delay amount of the first variable delay circuit so that the timing comparator acquires a data signal based on the timing clock, and a second adjusting section that adjusts a delay amount of the second variable delay circuit so that the timing compara