WO2011024394A1 - 変調された被試験信号の試験装置および試験方法 - Google Patents
変調された被試験信号の試験装置および試験方法 Download PDFInfo
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- WO2011024394A1 WO2011024394A1 PCT/JP2010/004995 JP2010004995W WO2011024394A1 WO 2011024394 A1 WO2011024394 A1 WO 2011024394A1 JP 2010004995 W JP2010004995 W JP 2010004995W WO 2011024394 A1 WO2011024394 A1 WO 2011024394A1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/317—Testing of digital circuits
- G01R31/3181—Functional testing
- G01R31/319—Tester hardware, i.e. output processing circuits
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/317—Testing of digital circuits
- G01R31/3181—Functional testing
- G01R31/319—Tester hardware, i.e. output processing circuits
- G01R31/31917—Stimuli generation or application of test patterns to the device under test [DUT]
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/317—Testing of digital circuits
- G01R31/31706—Testing of digital circuits involving differential digital signals, e.g. testing differential signal circuits, using differential signals for testing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/317—Testing of digital circuits
- G01R31/3181—Functional testing
- G01R31/319—Tester hardware, i.e. output processing circuits
- G01R31/3193—Tester hardware, i.e. output processing circuits with comparison between actual response and known fault free response
- G01R31/31932—Comparators
Definitions
- the present invention relates to a test apparatus.
- the digital wireless communication system transmits / receives multi-bit information on a carrier signal. That is, the data rate is not directly limited to the carrier frequency.
- a QAM (Quadrature ⁇ ⁇ Amplitude Modulation) transmission method which is the most basic orthogonal modulation / demodulation method can realize four-value transmission with one channel.
- 64QAM 64-value transmission can be realized with one carrier. That is, the transfer capacity can be improved by such a multi-level modulation method without increasing the carrier frequency.
- Such a modulation / demodulation method is not limited to wireless communication but can also be performed by wired communication, and has already begun to be applied as PAM (Pulse Amplitude Modulation), QPSK (Quadrature Phase Shift Keying) or DQPSK (Differential QPSK) method.
- PAM Pulse Amplitude Modulation
- QPSK Quadrature Phase Shift Keying
- DQPSK Differential QPSK
- Such a digital modulation / demodulation method may be applied to a wired interface between devices such as memory and SoC (System On a Chip). There is no channel testing equipment.
- test apparatuses and test modules have communication ports (I / O ports) for I / O (input / output) in the first place. Since it is usually limited to one or several, conventional test apparatuses and test modules have only a few communication ports. Therefore, it is difficult to use these test apparatuses and test modules for testing devices having I / O ports of tens to hundreds of channels or more such as memories.
- the signal output from the DUT (Device Under Test) is A / D (analog-digital) converted, and the enormous data obtained as a result is subjected to signal processing (including software processing). To determine the expected value. Therefore, the test time becomes long.
- the digital pins of the conventional test equipment basically assume only binary (in some cases, ternary with high impedance state Hi-Z added) test, and digital modulation signal Does not have a demodulation function.
- I / O of devices such as memory and MPU (Micro Processing Unit)
- MPU Micro Processing Unit
- I / O with several tens to hundreds of channels exists in one device, and hundreds of them. It is required to test at the same time. That is, a test apparatus having several thousand channels of digital modulation / demodulation signal input / output is required, and the CPU resource of the test apparatus is limited, so that real-time tests are all required at the hardware level.
- test apparatus capable of testing in real time test signals modulated by various methods such as amplitude modulation (AM), frequency modulation (FM), amplitude shift keying modulation (ASK), phase shift keying modulation (PSK), etc. can be used. Very useful for manufacturers.
- AM amplitude modulation
- FM frequency modulation
- ASK amplitude shift keying modulation
- PSK phase shift keying modulation
- the present invention has been made in view of such a situation, and one of exemplary purposes of an aspect thereof is to provide a test apparatus and a test method capable of testing a modulated signal under test at high speed.
- the test apparatus includes a cross timing measurement unit that generates cross timing data indicating a timing at which the level of the signal under test crosses each of a plurality of threshold values, and a plurality of threshold values for the expected value waveform expected for the signal under test.
- An expected value data generating unit that generates timing expected value data indicating a timing at which the expected value waveform crosses each threshold when compared with a value, and a comparing unit that compares the cross timing data with the timing expected value data.
- the quality of the device under test and the waveform quality of the signal under test are evaluated based on the timing at which the level of the signal under test changes, not the baseband signal obtained by demodulating the signal under test. Can do.
- Still another aspect of the present invention is a test apparatus.
- This device receives a cross timing data for generating cross timing data indicating the timing at which the level of the signal under test crosses each of a plurality of threshold values, and receives the cross timing data for each threshold value, and receives the time direction and amplitude.
- a waveform reconstruction unit that reconstructs the waveform of the signal under test by interpolating in the direction.
- the modulated signal under test can be tested at high speed.
- FIG. 3A is a time chart illustrating the operation of the cross timing data generation unit
- FIG. 3B is a diagram illustrating an expected value waveform, a plurality of threshold values, and timing expected value data.
- 4A to 4C are diagrams illustrating an example of comparison processing by the timing comparison unit.
- the test apparatus targets a device under test (DUT) having a digitally modulated digital data transmission / reception interface. That is, the pattern signal is digitally modulated and supplied to the DUT, and the digitally modulated data output from the DUT is compared with the expected value to determine whether the signal is good or bad.
- the test apparatus may include a function for analyzing the waveform of digitally modulated data, a function for generating a constellation map, and the like in addition to pass / fail determination.
- Digital modulation includes APSK (amplitude phase shift keying), QAM (quadrature amplitude shift keying), QPSK (quaternary phase shift keying), BPSK (binary phase shift keying), FSK (frequency shift keying) and the like.
- the DUT is assumed to be a device having a multi-channel I / O port such as a memory or MPU, but is not particularly limited.
- FIG. 1 is a block diagram showing a configuration of a test apparatus 2 according to the first embodiment of the present invention.
- the test apparatus 2 in FIG. 1 includes a plurality of I / O terminals PIO provided for each I / O port of the DUT 1.
- Each I / O pin P IO of the test apparatus 2 are connected via a transmission path and the corresponding I / O ports of DUT1, tested signal S1 modulated from DUT1 is input.
- I / O ports P IO number is arbitrary, in the case of the memory or MPU, provided several tens to hundreds or more, but for simplicity of facilitating the description of understanding the figure, a single I / O pin Only the PIO and associated blocks are shown.
- test apparatus 2 is provided with each I / O pin P IO, cross timing data generator 10, the expected value data generator 30, the three functional blocks of timing comparing section 40. Each will be described in turn below.
- the cross timing data generation unit 10 is a cross timing indicating the timing at which the level of the signal under test S1 crosses each of a plurality of threshold values V 0 to V N (N is a natural number). Data DCRS is generated.
- the cross timing data generation unit 10 includes a multi-value comparator 12, a threshold level setting unit 14, a time digital converter 16, and a real-time timing generator (hereinafter also referred to as a timing generator) 22.
- the real-time timing generator 22 may be installed for each cross timing data generation unit 10, or a single real-time timing generator 22 may be shared by a plurality of cross timing data generation units 10.
- the multi-value comparator 12 compares the level of the signal under test S1 with a plurality of threshold values V 0 to V N and outputs comparison data D CMP0 to D CMPN indicating the comparison result for each of the threshold values V 0 to V N.
- the i-th (0 ⁇ i ⁇ N) comparison data D CMPi is, for example, S1> when the V i 1 (high level) 0 when S1 ⁇ V i (low level) Take. The assignment of the high level and the low level may be reversed.
- the threshold values V 0 to V N are arranged at equal intervals.
- the present invention is not limited to this, and depending on the modulation method applied to the signal under test S1, the equal intervals are not necessarily optimal, and may be unequal intervals. That is, the threshold values V 0 to V N may be set appropriately according to the type of DUT 1 and the modulation method.
- comparison data D CMP0 to D CMPN are so-called thermometer codes in which 1 and 0 change (or take all 0 or all 1) with a certain bit as a boundary.
- the least significant bit comparison data D CMP0, the D CMPN to the most significant bit of the (N + 1) sets of bits collectively referred to as comparison code D CMP.
- the threshold level setting unit 14 generates threshold values V 0 to V N.
- the threshold level setting unit 14 is a D / A converter, and generates a threshold that can be adjusted in accordance with an external digital control signal.
- the threshold value may be dynamically controlled according to the type of DUT 1, the modulation method, or the like, or may be calibrated to a predetermined value with high accuracy in advance.
- the amplitude variation of the signal under test S1 from the DUT 1 may be allowed, or the DC offset may be allowed to vary.
- the threshold level setting unit 14 may measure the amplitude and DC offset of the signal under test S1 and optimize the threshold values V 0 to V N based on the measurement result.
- the time digital converter 16 receives the comparison data D CMP0 to D CMPN for each of the threshold values V 0 to V N and measures the timing at which each of the comparison data D CMP0 to D CMPN changes to thereby detect the cross timing data DCRS0. Generate D CRSN .
- the cross timing data D CRS0 to D CRS0 are generated for each threshold value.
- a single cross timing data DCRS indicating the timing at which any of the plurality of comparison data DCMP changes may be generated.
- the time digital converter 16 includes a latch array 18 and an encoder 20.
- FIG. 2 is a circuit diagram showing a configuration example of the latch array 18.
- the timing generator 22 generates K-phase (K is an integer) multi-strobe signals STRB 1 to STRB K in which the phase of each edge is shifted by a predetermined sampling interval Ts.
- the sampling interval Ts is set according to the symbol rate (frequency) of the signal under test S1 and the modulation method. For example, the sampling period Ts is set to 1 / integer (eg, 1/8 times) of the symbol period Tsym (reciprocal of the symbol rate) of the signal under test S1. That is, the latch array 18 oversamples the comparison data D CMP0 to D CMPN at a predetermined frequency.
- the latch array 18 has K flip-flops FF 1 to FF K for each of the comparison data D CMP0 to D CMPN .
- the i-th comparison data D CMPi is input to K flip-flops corresponding thereto.
- K-phase multi-strobe signals STRB 1 to STRB K are input to clock terminals of the K flip-flops, respectively.
- the output data of each of the flip-flops FF 1 to FF K is a K-bit thermometer code (hereinafter referred to as timing code TC).
- timing code TC K-bit thermometer code
- the output of FF 1 is assigned to the most significant bit (MSB)
- the output of FF K is assigned to the least significant bit (LSB).
- the timing generator 22 may repeatedly generate the strobe signals STRB 1 to STRB K with reference to the test rate (period T RATE ). An index (j) is attached to the repeated test rate.
- the i-th timing code TC i indicates the timing at which the signal under test S1 crosses the i-th threshold value V i .
- t j ⁇ T RATE + (L ⁇ Ts) Represents the cross timing (elapsed time from the start of the test).
- the value L can be calculated by priority encoding the timing code TC i .
- the encoder 20 receives the timing code TC and generates cross timing data D CRS0 to D CRSN indicating the cross timing t.
- the data format of the cross timing data D CRS0 to D CRSN is arbitrary, but may include a pair of values j and L.
- FIG. 3A is a time chart showing the operation of the cross timing data generation unit 10.
- the solid line under test signals S1 dashed line shows a comparison code D CMP which is digitized by the multi-level comparator 12.
- the cross timing sequences t 0 ′ to t 8 ′ indicate timings when the value of the comparison code DCMP changes.
- cross timing data generation unit 10 The above is the configuration and operation of the cross timing data generation unit 10. Note that the configuration of the cross timing data generation unit 10 is not limited to that described above, and may be configured in other circuit formats.
- the test apparatus 2 knows what pattern data the signal under test S1 output from the DUT 1 is based on. This is called an expected value or a baseband expected value pattern.
- the expected value pattern generator 32 generates a binary baseband expected value pattern PAT.
- the expected value pattern PAT is data corresponding to one symbol, and is 4 bits in the case of 16QAM. The number of bits of the expected value pattern PAT is set according to the modulation method.
- the encoding circuit 34 virtually digital multi-value modulates the baseband expected value pattern PAT by digital signal processing in the same manner as the DUT 1, and generates an expected value waveform S2 obtained as a result.
- the expected value pattern generator 32 compares the expected value waveform S2 expected for the signal under test S1 with a plurality of threshold values V 0 to V N , the expected value waveform S2 is converted into each threshold value V 0 to Timing expected value data DT EXP indicating the timing of crossing V N is generated by digital signal processing.
- FIG. 3B shows an expected value waveform S2, threshold values V 0 to V N and timing expected value data DT EXP .
- the expected timing value data DT EXP includes expected value cross timings t 0 , t 1 .
- the encoding circuit 34c outputs rate setting data RATE indicating the rate of the expected timing value data DT EXP .
- the timing generator 22 receives the rate setting data RATE and generates a strobe signal STRB including an edge sequence with an interval corresponding to the value in synchronization with the rate clock.
- the timing comparison unit 40 receives the cross timing data D CRS (t 0 ′, t 1 ′) and the expected timing value data DT EXP (t 0 , t 1 ,). By comparing, the quality of DUT1 is determined, or the defective part is specified.
- FIG. 4A to 4C are diagrams illustrating an example of comparison processing by the timing comparison unit 40.
- FIG. 4A By the waveform distortion or the like, the measured cross timing data D CRS is, indicating a value outside the range of tolerance ⁇ T in comparison with the timing expected value data DT EXP, it is possible to determine the DUT1 defective.
- An upper limit value and a lower limit value window of the expected value timing t may be provided, and it may be determined whether or not the measured cross timing t ′ is included in the window.
- the cross timing t 8 ′ with respect to the threshold value V 3 deviates from the range of the expected value t 8 .
- FIG. 4B shows a case where amplitude degradation has occurred in the signal under test S1 from the DUT1.
- FIG. 4C shows a case where a DC offset has occurred in the signal under test S1.
- the measured cross timing t 'deviates from the expected value timing t also due to amplitude deterioration and DC offset. Therefore, according to the test apparatus 2 according to the embodiment, these defects can also be detected.
- FIG. 5 is a block diagram showing a configuration of a test apparatus 2a according to the second embodiment of the present invention.
- the test apparatus 2a includes a waveform reconstruction unit 50 and a waveform analysis unit 52 in place of or in addition to the timing comparison unit 40 of the first embodiment. A description of the same blocks as those in FIG. 1 is omitted.
- the waveform reconstruction unit 50 receives the cross timing data D CRS0 to D CRSN for each of the threshold values V 0 to V N. These data are nothing but the representation of the signal under test S1 in the form of a column of (t k , V i ). k is an integer indicating a sampling index number. I (0 ⁇ i ⁇ N) represents an index number indicating a threshold level.
- the waveform reconstruction unit 50 reconstructs the waveform of the signal under test S1 with digital values by interpolating in the time direction and the amplitude direction.
- FIG. 6 is a diagram illustrating how various modulated waves are sampled by the cross timing data generation unit 10. While general sampling is performed with respect to the time axis direction, the present embodiment is characterized in that sampling is performed with reference to threshold values V 0 to V N in the amplitude direction.
- FIG. 7 is a diagram illustrating a waveform reconstructed by the waveform reconstructing unit 50.
- a white circle indicates a point sampled with reference to a threshold, and a black circle indicates a point interpolated.
- the waveform reconstruction unit 50 is a DSP (Digital Signal Processor) or a computer that can execute signal processing such as linear interpolation, polynomial interpolation, and cubic spline interpolation. Considering the convenience of signal processing in the subsequent stage, it is desirable that the waveform reconstruction unit 50 interpolates the cross timing data DCRS for each threshold value V at equal intervals in the time axis direction.
- the interpolated waveform data S3 is input to the waveform analysis unit 52.
- the waveform analysis unit 52 performs signal processing on the reconstructed waveform data S3, and performs analysis or modulation analysis in the time domain or frequency domain of the signal under test S1.
- the waveform data S3 may be subjected to Fourier transform (Fast Fourier Transform, FFT) and converted to the frequency domain, followed by spectrum analysis or phase noise analysis (single sideband phase noise spectrum analysis) of the signal under test S1. Good.
- FFT Fast Fourier Transform
- phase noise analysis single sideband phase noise spectrum analysis
- eye diagram analysis or jitter analysis of the signal under test S1 may be performed.
- modulation analysis may be applied to the waveform data S3 to create a constellation map.
- time domain and frequency domain analysis and modulation analysis can be performed by a single test apparatus without using a spectrum analyzer or a digitizer.
- FIG. 8 is a block diagram showing a partial configuration of the test apparatus 2b according to the first modification. These modifications can be applied to both the test apparatus 2 in FIG. 1 and the test apparatus 2a in FIG. The configuration subsequent to the multi-value comparator 12 is omitted because it is the same as the device of FIG. 1 or FIG. 5 or a combination thereof.
- the test apparatus 2b includes a level adjustment unit 13 in front of the multi-value comparator 12.
- the level adjusting unit 13 has a function of changing at least one of the amplitude component and the DC offset of the signal under test S1, and can be configured by any one of a variable attenuator, a variable amplifier, a level shifter, or a combination thereof.
- the level adjuster 13 may measure the peak voltage value, amplitude, DC offset, etc. of the signal under test S1, and control the attenuation rate, gain, and offset amount accordingly. For this control, a so-called AGC (Automatic Gain Control) circuit may be used.
- AGC Automatic Gain Control
- the DUT 1 when the amplitude variation and the DC offset variation are allowed in the signal under test S1, the DUT 1 can be evaluated in a state in which those influences are excluded.
- FIG. 9 is a block diagram showing a configuration of a test apparatus 2c according to the second modification.
- the modification of FIG. 9 further includes a retiming processing unit 70 and a level comparison unit 72 in addition to the components of FIGS.
- the timing comparison unit 40 determines whether the timing at which the signal under test S1 crosses a certain threshold level matches the expected value.
- the level comparison unit 72 determines whether the amplitude level at a certain timing of the signal under test S1 matches the expected value.
- the expected value data generation unit 30c includes an expected value pattern generator 32 and an encoding circuit 34c.
- the expected value pattern generator 32 generates an expected value pattern PAT indicating expected value data from the DUT 1.
- the encoding circuit 34c receives the expected value pattern PAT and encodes it, thereby generating amplitude expected value data DA EXP in addition to the timing expected value data DT EXP .
- the encoding process of the expected timing value data DT EXP is as described above.
- the generation process of the expected amplitude data DA EXP is executed as follows.
- Amplitude expected value data DA EXP indicating to which of the plurality of amplitude segments SEG 0 to SEG N + 1 the amplitude level for each sampling point of the modulated signal waveform is generated.
- the encoding process may be performed by reading out amplitude expected value data DA EXP prepared in advance for each value of the expected value pattern PAT from the memory. Alternatively, numerical calculation processing may be performed.
- the multi-value comparator 12, the threshold level setting unit 14, the latch array 18, and the retiming processing unit 70 convert the signal under test S1 into a signal format that can be compared with the amplitude expected value data DA EXP .
- this conversion processing is called demodulation, and is different from general demodulation processing in which a baseband signal is extracted by frequency mixing.
- the multi-value comparator 12 compares the signal under test S1 with threshold values V 0 to V N that define the boundaries of the plurality of amplitude segments SEG 0 to SEG N + 1 , and generates a plurality of comparison data D CMP0 to D CMPN . .
- the threshold level setting unit 14 sets the threshold level of the multi-value comparator 12 according to the number of amplitude segments, the voltage range of the input signal under test S1 and the modulation method.
- the latch array 18 operates in the same manner as the latch array 18 shown in FIGS. That is, the comparison data D CMP0 to D CMPN output from the multi-value comparator 12 are latched at every predetermined sampling timing defined by the strobe signal STRB.
- determination data TC 0 to TC N latched by the latch array 18 indicate to which amplitude segment the signal under test S1 belongs at each sampling timing.
- the retiming processing unit 70 receives the determination data TC 0 to TC N latched by the latch array 18. Retiming processing unit 70, for synchronization with the subsequent level comparing section 72, the judgment data TC 0 ⁇ TC N and retiming to match the rate of the amplitude expected value data DA EXP.
- the encoding circuit 34c outputs the timing data TD indicating the time interval of the sampling points together with the amplitude expected value data DA EXP .
- the timing generator 70 generates a strobe signal STRB including a pulse edge sequence PE1 having an interval corresponding to the timing data TD.
- the encoding circuit 34c outputs rate setting data RATE indicating the rate of the expected amplitude data DA EXP .
- the timing generator 70 receives the rate setting data RATE and generates a second pulse edge sequence PE2 having a frequency corresponding to the value.
- the retiming processing unit 70 synchronizes the plurality of determination data TC 0 to TC N from the latch array 18 with the timing of the second pulse edge sequence PE2.
- Level comparison unit 72 receives the determination data TC 0 ⁇ TC N and amplitude expected value data DA EXP retimed by retiming processing unit 68, at each sampling timing based on these, of the test signal S1 from DUT1 It is determined whether the amplitude belongs to the expected amplitude segment.
- FIG. 10 is a diagram conceptually illustrating a comparison process between the expected amplitude data and the determination data in the level comparison unit 72.
- the solid line waveform indicates the signal under test S1.
- the amplitude is divided into a plurality of segments SEG 0 to SEG N + 1 .
- a one-dot chain line indicates a window corresponding to an expected modulated signal waveform of a symbol, that is, an expected value waveform S2, and is defined by amplitude expected value data DA EXP .
- expected amplitude value data DA EXP defining a window corresponding to 16 symbols is output from the encoding circuit 34c.
- the window for each symbol may be set according to a modulation scheme, a coding scheme such as Gray coding, an expected amplitude error, and a phase error.
- FIG. 10 shows an expected value window corresponding to the symbol (0100).
- Level comparing section 72 compares the amplitude expected value data DA EXP defining the window, the amplitude level of the test signal S1 shown determination data TC 0 ⁇ TC N. As a result, it can be determined whether or not the symbol of the signal under test S1 matches the expected value.
- one sampling timing may be arranged at the center of the window time width Tw.
- pulse edge PE1b you may arrange
- the pulse edge frequency may be set as high as possible to highly digitize the signal under test S1.
- the signal under test S1 can be evaluated from both the time axis direction and the amplitude direction.
- FIG. 1 A configuration in which the retiming processing unit 70 and the level comparison unit 72 are added to FIG. 1 and a configuration in which the retiming processing unit 70 and the level comparison unit 72 are added to FIG. 5 are also effective as an aspect of the present invention.
- test apparatus In the embodiment, it does not matter whether the transmission line connecting the DUT 1 and the test apparatus 2 is wired or wireless. Moreover, the test apparatus according to the present invention can be used not only for modulated signals but also for various analog signal tests in general.
- the signal under test S1 from the DUT 1 is generated in synchronization with the internal rate clock of the test apparatus 2.
- the strobe signal (pulse edge train) STRB provided to the latch array 18 by the timing generator 22 may be generated in synchronization with the rate clock. If the signal under test S1 is generated asynchronously with the rate clock, preamble data is inserted as a training sequence at the head of the signal under test S1, and the reference clock is reproduced using the training sequence.
- the strobe signal STRB may be generated in synchronization with the reference clock.
- the present invention can be used for a test apparatus.
Abstract
Description
図1は、本発明の第1の実施の形態に係る試験装置2の構成を示すブロック図である。図1の試験装置2は、DUT1のI/Oポートごとに設けられた複数のI/O端子PIOを備える。試験装置2のI/O端子PIOはそれぞれ、DUT1の対応するI/Oポートと伝送路を介して接続されており、DUT1からの変調された被試験信号S1が入力される。I/OポートPIOの個数は任意であり、メモリやMPUの場合、数十~百個以上設けられるが、図では理解の容易化と説明の簡略化のため、単一のI/O端子PIOとそれに関連するブロックのみを示す。
クロスタイミングデータ生成部10は、被試験信号S1のレベルが、複数のしきい値V0~VN(Nは自然数)それぞれとクロスするタイミングを示すクロスタイミングデータDCRSを生成する。
S1>Viのとき1(ハイレベル)
S1<Viのとき0(ローレベル)
をとる。なお、ハイレベル、ローレベルの割り当ては反対であってもよい。本実施の形態において、しきい値V0~VNは等間隔に配置される。ただし本発明はこれに限定されず、被試験信号S1に施される変調方式によっては、等間隔が最適であるとは限らず不等間隔であってもよい。つまりしきい値V0~VNは、DUT1の種類、変調方式などに応じて適切に設定すればよい。
タイミング発生器22は、それぞれのエッジの位相が所定のサンプリング間隔TsずつシフトしているK相(Kは整数)のマルチストローブ信号STRB1~STRBKを発生する。サンプリング間隔Tsは、被試験信号S1のシンボルレート(周波数)や変調方式に応じて設定される。たとえばサンプリング期間Tsは、被試験信号S1のシンボル期間Tsym(シンボルレートの逆数)の整数分の1(たとえば1/8倍)に設定される。つまりラッチアレイ18は、比較データDCMP0~DCMPNを所定の周波数でオーバーサンプリングする。
t=j×TRATE+(L×Ts)
が、クロスタイミング(テスト開始からの経過時間)を表す。値Lは、タイミングコードTCiをプライオリティエンコードすることで算出することができる。エンコーダ20は、タイミングコードTCを受け、クロスタイミングtを示すクロスタイミングデータDCRS0~DCRSNを発生する。クロスタイミングデータDCRS0~DCRSNのデータ形式は任意であるが、値jとLのペアを含んでもよい。
また、クロスタイミング列t0’~t8’は、比較コードDCMPの値が変化するタイミングを示す。
続いて図1に戻り、期待値データ生成部30について説明する。
試験装置2は、DUT1から出力される被試験信号S1が、どのようなパターンデータにもとづいているかを知っている。これを期待値またはベースバンド期待値パターンという。期待値パターン発生器32は、2値のベースバンド期待値パターンPATを発生する。期待値パターンPATは、1シンボルに相当するデータであり、16QAMの場合4ビットとなる。期待値パターンPATのビット数は、変調方式に応じて設定される。
タイミング比較部40は、クロスタイミングデータDCRS(t0’、t1’・・・)とタイミング期待値データDTEXP(t0、t1、・・・)を比較することにより、DUT1の良否を判定し、あるいはその不良箇所を特定する。
波形歪み等によって、測定されたクロスタイミングデータDCRSが、タイミング期待値データDTEXPに比べて許容量ΔTの範囲をはずれた値を示す場合、DUT1を不良と判定することができる。期待値タイミングtの上限値と下限値のウインドウを設け、測定されたクロスタイミングt’がウインドウに含まれるか否かを判定すればよい。図4(a)では、しきい値V3に対するクロスタイミングt8’が、期待値t8の範囲から逸脱している。
図5は、本発明の第2の実施の形態に係る試験装置2aの構成を示すブロック図である。試験装置2aは、第1の実施の形態のタイミング比較部40に代えて、またはそれに加えて、波形再構成部50および波形解析部52を備える。図1と重複するブロックの説明は省略する。
図8は、第1の変形例に係る試験装置2bの一部の構成を示すブロック図である。これらの変形例は、図1の試験装置2および図5の試験装置2aいずれの実施の形態にも適用可能である。多値コンパレータ12より後段の構成は、図1もしくは図5、あるいはそれらの組み合わせの装置と同様であるため省略されている。
図9は、第2の変形例に係る試験装置2cの構成を示すブロック図である。図9の変形例は、図1、図5の構成要素に加えて、リタイミング処理部70およびレベル比較部72をさらに備える。
実施の形態において、DUT1と試験装置2を接続する伝送線路は、有線であると無線であるとを問わない。また本発明に係る試験装置は、変調された信号のみでなく、さまざまなアナログ信号の試験全般に利用することができる。
もし被試験信号S1がレートクロックと非同期で生成される場合には、被試験信号S1の先頭にトレーニングシーケンスとしてプリアンブルデータを挿入しておき、トレーニングシーケンスを利用して基準クロックを再生し、再生された基準クロックと同期してストローブ信号STRBを生成すればよい。
Claims (10)
- 被試験デバイスからの変調された被試験信号を試験する試験装置であって、
前記被試験信号のレベルが、複数のしきい値それぞれとクロスするタイミングを示すクロスタイミングデータを生成するクロスタイミング測定部と、
前記被試験信号に期待される期待値波形を前記複数のしきい値と比較した場合に前記期待値波形が各しきい値とクロスするタイミングを示すタイミング期待値データを生成する期待値データ生成部と、
前記クロスタイミングデータと前記タイミング期待値データを比較する比較部と、
を備えることを特徴とする試験装置。 - 前記クロスタイミング測定部は、
前記被試験信号のレベルを前記複数のしきい値と比較し、各しきい値ごとに比較結果を示す比較データを生成する多値コンパレータと、
前記しきい値ごとの前記比較データを受け、前記比較データが変化するタイミングを測定することにより、前記クロスタイミングデータを生成する時間デジタル変換器と、
を含むことを特徴とする請求項1に記載の試験装置。 - 前記時間デジタル変換器は、
前記多値コンパレータからの比較データを所定の周波数でサンプリングするラッチアレイと、
前記ラッチアレイから出力されるラッチデータにもとづき、前記クロスタイミングデータを生成するエンコーダと、
を含むことを特徴とする請求項2に記載の試験装置。 - しきい値ごとの前記クロスタイミングデータを受け、時間方向および振幅方向に補間することにより、前記被試験信号の波形を再構成する波形再構成部をさらに備えることを特徴とする請求項1から3のいずれかに記載の試験装置。
- 前記波形再構成部は、しきい値ごとの前記クロスタイミングデータを、時間軸方向に等間隔に補間することを特徴とする請求項4に記載の試験装置。
- 被試験デバイスからの変調された被試験信号を試験する方法であって、
前記被試験信号のレベルが、複数のしきい値それぞれとクロスするタイミングを示すクロスタイミングデータを生成するステップと、
前記被試験信号に期待される期待値波形を前記複数のしきい値と比較した場合に前記期待値波形が各しきい値とクロスするタイミングを示すタイミング期待値データを生成するステップと、
前記クロスタイミングデータと前記タイミング期待値データを比較するステップと、
を備えることを特徴とする方法。 - 被試験デバイスからの変調された被試験信号を試験する試験装置であって、
前記被試験信号のレベルが、複数のしきい値それぞれとクロスするタイミングを示すクロスタイミングデータを生成するクロスタイミング測定部と、
しきい値ごとの前記クロスタイミングデータを受け、時間方向および振幅方向に補間することにより、前記被試験信号の波形を再構成する波形再構成部と、
を備えることを特徴とする試験装置。 - 前記波形再構成部により再構成された前記被試験信号の波形を解析する波形解析部をさらに備えることを特徴とする請求項7に記載の試験装置。
- 前記波形再構成部は、しきい値ごとの前記クロスタイミングデータを、時間軸方向に等間隔に補間することを特徴とする請求項7に記載の試験装置。
- 被試験デバイスからの変調された被試験信号を試験する試験装置であって、
前記被試験信号のレベルが、複数のしきい値それぞれとクロスするタイミングを示すクロスタイミングデータを生成するステップと、
しきい値ごとの前記クロスタイミングデータを受け、時間方向および振幅方向に補間することにより、前記被試験信号の波形を再構成するステップと、
を備えることを特徴とする方法。
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CN2010800375271A CN102483440A (zh) | 2009-08-26 | 2010-08-09 | 调制后的被测试信号的测试装置以及测试方法 |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2021009042A (ja) * | 2019-06-28 | 2021-01-28 | 株式会社アドバンテスト | 信号処理装置および信号処理方法 |
Families Citing this family (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3930037B1 (ja) * | 2006-04-27 | 2007-06-13 | 株式会社アドバンテスト | 試験装置および試験方法 |
JP5274551B2 (ja) * | 2008-05-09 | 2013-08-28 | 株式会社アドバンテスト | デジタル変調信号の試験装置および試験方法 |
DE102016119244B4 (de) * | 2015-11-27 | 2020-10-01 | Roentdek-Handels Gmbh | Zeit-zu-Digital-Konverter |
CN110070906A (zh) * | 2019-04-10 | 2019-07-30 | 晶晨半导体(上海)股份有限公司 | 一种存储系统的信号调试方法 |
US10803914B1 (en) * | 2019-08-27 | 2020-10-13 | Micron Technology, Inc. | Selectively squelching differential strobe input signal in memory-device testing system |
US11102596B2 (en) | 2019-11-19 | 2021-08-24 | Roku, Inc. | In-sync digital waveform comparison to determine pass/fail results of a device under test (DUT) |
US10892800B1 (en) | 2020-01-06 | 2021-01-12 | Nucurrent, Inc. | Systems and methods for wireless power transfer including pulse width encoded data communications |
US11303165B2 (en) | 2020-07-24 | 2022-04-12 | Nucurrent, Inc. | Low cost communications demodulation for wireless power receiver system |
US11303164B2 (en) | 2020-07-24 | 2022-04-12 | Nucurrent, Inc. | Low cost communications demodulation for wireless power transmission system |
US11569694B2 (en) * | 2021-02-01 | 2023-01-31 | Nucurrent, Inc. | Automatic gain control for communications demodulation in wireless power receivers |
US11811244B2 (en) | 2021-02-01 | 2023-11-07 | Nucurrent, Inc. | Automatic gain control for communications demodulation in wireless power transmitters |
US11431204B2 (en) | 2021-02-01 | 2022-08-30 | Nucurrent, Inc. | Automatic gain control for communications demodulation in wireless power transfer systems |
US11277031B1 (en) | 2021-02-01 | 2022-03-15 | Nucurrent, Inc. | Automatic gain control for communications demodulation in wireless power transmitters |
US11431205B2 (en) | 2021-02-01 | 2022-08-30 | Nucurrent, Inc. | Systems and methods for receiver beaconing in wireless power systems |
US11277034B1 (en) | 2021-02-01 | 2022-03-15 | Nucurrent, Inc. | Systems and methods for receiver beaconing in wireless power systems |
US11277035B1 (en) | 2021-02-01 | 2022-03-15 | Nucurrent, Inc. | Automatic gain control for communications demodulation in wireless power transmitters |
CN114675236B (zh) * | 2022-05-25 | 2022-08-23 | 中达天昇(江苏)电子科技有限公司 | 一种任意频域形状实信号波形调制技术 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01311282A (ja) * | 1988-06-08 | 1989-12-15 | Yokogawa Electric Corp | 波形表示装置 |
JPH06242185A (ja) * | 1993-02-15 | 1994-09-02 | Fujitsu Ltd | 信号波形測定装置及び信号波形測定方法 |
WO2007088603A1 (ja) * | 2006-02-01 | 2007-08-09 | Fujitsu Limited | 半導体装置及びノイズ計測方法 |
WO2008114699A1 (ja) * | 2007-03-21 | 2008-09-25 | Advantest Corporation | 試験装置および測定回路 |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0471119A1 (en) * | 1990-08-14 | 1992-02-19 | Hewlett-Packard Limited | Waveform measurement |
US20040183769A1 (en) * | 2000-09-08 | 2004-09-23 | Earl Schreyer | Graphics digitizer |
US6429799B1 (en) * | 2001-07-14 | 2002-08-06 | Agilent Technologies, Inc. | Method and apparatus for analog to digital conversion using time-varying reference signal |
WO2003073280A1 (en) * | 2002-02-26 | 2003-09-04 | Advantest Corporation | Measuring apparatus and measuring method |
US20040123018A1 (en) * | 2002-09-30 | 2004-06-24 | Martin Miller | Method and apparatus for analyzing serial data streams |
US6717540B1 (en) * | 2002-10-10 | 2004-04-06 | Agilent Technologies, Inc. | Signal preconditioning for analog-to-digital conversion with timestamps |
JP4429625B2 (ja) * | 2003-04-25 | 2010-03-10 | 株式会社アドバンテスト | 測定装置、及びプログラム |
US7496169B2 (en) * | 2004-09-14 | 2009-02-24 | Nippon Precision Circuits Inc. | Frequency synthesizer, pulse train generation apparatus and pulse train generation method |
US7398169B2 (en) | 2006-02-27 | 2008-07-08 | Advantest Corporation | Measuring apparatus, measuring method, testing apparatus, testing method, and electronics device |
US7681091B2 (en) * | 2006-07-14 | 2010-03-16 | Dft Microsystems, Inc. | Signal integrity measurement systems and methods using a predominantly digital time-base generator |
GB2444953B (en) * | 2006-12-19 | 2009-07-22 | Westerngeco Seismic Holdings | Method for obtaining an image of a subsurface by regularizing irregularly sampled seismic data |
WO2009001451A1 (ja) * | 2007-06-27 | 2008-12-31 | Advantest Corporation | 検出装置及び試験装置 |
-
2009
- 2009-08-26 US US12/548,399 patent/US20110054827A1/en not_active Abandoned
-
2010
- 2010-08-09 WO PCT/JP2010/004995 patent/WO2011024394A1/ja active Application Filing
- 2010-08-09 CN CN2010800375271A patent/CN102483440A/zh active Pending
- 2010-08-09 JP JP2011528629A patent/JPWO2011024394A1/ja not_active Ceased
- 2010-08-09 KR KR1020127007268A patent/KR101334445B1/ko not_active IP Right Cessation
- 2010-08-09 DE DE112010003393T patent/DE112010003393T8/de not_active Expired - Fee Related
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01311282A (ja) * | 1988-06-08 | 1989-12-15 | Yokogawa Electric Corp | 波形表示装置 |
JPH06242185A (ja) * | 1993-02-15 | 1994-09-02 | Fujitsu Ltd | 信号波形測定装置及び信号波形測定方法 |
WO2007088603A1 (ja) * | 2006-02-01 | 2007-08-09 | Fujitsu Limited | 半導体装置及びノイズ計測方法 |
WO2008114699A1 (ja) * | 2007-03-21 | 2008-09-25 | Advantest Corporation | 試験装置および測定回路 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2021009042A (ja) * | 2019-06-28 | 2021-01-28 | 株式会社アドバンテスト | 信号処理装置および信号処理方法 |
JP7217204B2 (ja) | 2019-06-28 | 2023-02-02 | 株式会社アドバンテスト | 信号処理装置および信号処理方法 |
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