JP5290213B2 - Error rate measuring apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically detect the data length of an inputted measured signal, and also to observe the waveform of a bit string waveform in the measured signal. <P>SOLUTION: An error rate detecting part 20 identifies the pattern of a signal level in the measured signal which is inputted via a tested device 50, compares identification pattern data indicating the identification result with a reference pattern held by a reference pattern generating part 10, and then calculates an error rate. Next, the calculated error rate is compared with a predetermined reference error rate threshold, and when the calculated error rate becomes lower than the reference error rate threshold, it is determined that pattern synchronization is obtained between the compared reference pattern and measured signal, and the bit number N of the reference pattern synchronized in pattern with the measured signal is multiplied by integer to obtain a frequency division ratio M. Then, a waveform observing part 40 performs the display control of a signal waveform in the measured signal, based on the M frequency division information indicating the frequency division ratio M. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an error rate measuring apparatus that performs bit error rate measurement and waveform measurement / display of a signal under measurement input via a device under test, and in particular automatically detects the data length of the input signal under measurement, The present invention relates to an error rate measuring apparatus and method capable of observing a waveform of a bit string of the signal under measurement.

  In recent years, various types of digital wired communication devices are required to have a larger capacity transmission capability with the increase in the number of users and the spread of multimedia communication. As an index for evaluating the quality of digital signals in these digital wired communication apparatuses, a bit error rate (Bit Error Rate) defined as a comparison between the number of received code errors and the total number of received data. )It has been known.

  In addition, a test signal including fixed data is sent to the device under test (Device Under Test), such as a photoelectric conversion component to be tested, and the signal under measurement input via the device under test and a reference signal as a reference For example, an error rate measuring device as disclosed in Patent Document 1 below is known as a device that detects the error rate of a signal under measurement by comparing the above with bit by bit.

FIG. 6 is a schematic configuration diagram of an error rate measuring apparatus disclosed in Patent Document 1 below. As shown in the figure, the bit error measuring apparatus 100 includes a data storage unit 101 configured by a memory such as a RAM, a comparison data storage unit 102, a position information storage unit 103, and a signal transmission unit 104 configured by an integrated circuit or the like. , A signal reception unit 105, a synchronization detection unit 106, a comparison unit 107, a display control unit 108, a display device 109 such as a CRT or a liquid crystal display, and an operation unit 110 such as a keyboard. by comparing the known data to be received from the data measurement target 200 in the bit error measurement apparatus 100 that measures an error bit, a comparison data storage unit 10 2 having a plurality of blocks, the input data and the known received A ratio of bit strings including one or a plurality of detection bits detected by comparing with data and detected under a predetermined detection condition The compare data, the comparator unit 107 which sequentially stores the plurality of blocks in response to being detected, the respective bit sequence obtained from the comparison data stored in the plurality of blocks, according to a predetermined arrangement condition position constitute a display control unit 108 to be displayed on the display device 109 side by side with respect to the.

JP 2007-274474 A

  By the way, when an error rate of a device under test is measured using a conventional error rate measurement device including the error rate measurement device of Patent Document 1 described above, if an abnormality is found in the measurement result, a signal waveform of an oscilloscope or the like is displayed. The cause of the problem is investigated by measuring and displaying the waveform of the signal under measurement input from the device under test using the waveform observer to measure and display.

At this time, for example, when displaying the bit string waveform of the signal under measurement having a data length of N bits with a waveform observer, an external trigger signal synchronized with the pattern period N of the signal under measurement is input, or the M divider circuit Therefore, it is necessary to preset a frequency division ratio M that is an integral multiple of the pattern period N of the signal under measurement and generate a trigger signal that internally matches the pattern period N.
For this reason, it is difficult to observe the bit string waveform by the waveform observer when the external trigger signal cannot be obtained or when the pattern period N of the input signal under measurement is unknown.

  Accordingly, the present invention has been made in view of the above problems, and has an error rate measurement function and a waveform observation function, and can automatically recognize the data length of the input signal under measurement and display the bit string waveform of the signal. It is an object of the present invention to provide a simple error rate measuring apparatus and method.

To achieve the above object, the error rate measuring apparatus according to claim 1 includes an error rate detecting unit 20 for detecting a bit error rate of a signal under measurement input via the device under test 50, and the signal under measurement. An error rate measuring apparatus 1 having a waveform observing unit 40 that performs waveform observation of
The error rate detector is
A data identifying unit 21 for identifying a signal level pattern of the signal under measurement based on a clock timing of a reproduction clock synchronized with a bit rate of the signal under measurement, and outputting the identified pattern as identification pattern data;
An error rate calculated by comparing the identification pattern data input from the data identification unit with a reference pattern to be compared for calculating an error rate of the identification pattern data, and a degree of pattern synchronization A reference error rate threshold value is compared, and when the error rate falls below the reference error rate threshold value, information on a frequency division ratio M obtained by multiplying the number N of bits of the reference pattern synchronized with the signal under measurement by an integer is obtained. A data analysis unit 22 that outputs M division information to the waveform observation unit;
It is provided with.

The error rate measuring apparatus according to claim 2 includes an error rate detection unit 20 that detects a bit error rate of a signal under measurement input via the device under test 50, and a waveform observation unit 40 that performs waveform observation of the signal under measurement. And an error rate measuring apparatus 1 comprising:
The error rate detector is
A data identifying unit 21 for identifying a signal level pattern of the signal under measurement based on a clock timing of a reproduction clock synchronized with a bit rate of the signal under measurement, and outputting the identified pattern as identification pattern data;
It holds the first input pattern of the identification pattern data input from the data identification unit as the first pattern, and comparing said identification pattern data and the top pattern while counting the number of bits of the identification pattern data, the identification pattern A data analysis unit that outputs information on the frequency division ratio M, which is an integer multiple of the number N of bits of the identification pattern data counted until the data once circulates and again matches the head pattern, to the waveform observation unit as M frequency division information 22,
It is provided with.

  The error rate measurement device according to claim 3 is the error rate measurement device according to claim 1, wherein the data analysis unit 22 uses a plurality of the reference patterns when comparing the calculated error rate and the reference pattern. When the error rate exceeds the reference error rate threshold when all the reference patterns in the configured reference pattern group are compared, the error rate is calculated again using the reference pattern with the lowest error rate error. It is characterized by doing.

The error rate measurement method according to claim 4 is an error rate detection step for detecting a bit error rate of a signal under measurement input via the device under test 50, and a waveform observation unit 40 performs waveform observation of the signal under measurement. An error rate measurement method comprising a waveform observation step,
The error rate detection step includes:
A data identification step of identifying a signal level pattern of the signal under measurement based on a clock timing of a reproduction clock synchronized with a bit rate of the signal under measurement, and outputting the identified pattern as identification pattern data;
To determine the error rate calculated by comparing the identification pattern data output from the data identification step with a reference pattern to be compared for calculating the error rate of the identification pattern data, and the degree of pattern synchronization When the error rate falls below the reference error rate threshold, information on the frequency division ratio M obtained by multiplying the number N of bits of the reference pattern synchronized with the signal under measurement by an integer A data analysis step of outputting to the waveform observation unit as M frequency division information;
It is characterized by including.

The error rate measurement method according to claim 5 is an error rate detection step for detecting a bit error rate of a signal under measurement input via the device under test 50, and a waveform observation unit 40 performs waveform observation of the signal under measurement. An error rate measurement method comprising a waveform observation step,
The error rate detection step includes:
A data identification step of identifying a signal level pattern of the signal under measurement based on a clock timing of a reproduction clock synchronized with a bit rate of the signal under measurement, and outputting the identified pattern as identification pattern data;
Holds the first input pattern data of the identification pattern data output from the data identification step as the head pattern, comparing said identification pattern data and the top pattern while counting the number of bits of the identification pattern data , Information on the frequency division ratio M, which is an integer multiple of the number N of bits of the identification pattern data counted until the identification pattern data circulates once and coincides with the head pattern again, is output to the waveform observation unit as M frequency division information Data analysis step to perform,
It is characterized by including.

  According to the error rate measuring apparatus of the present invention, when a signal under measurement of a known pulse pattern is input via the device under test, the data length of the bit string of the signal under measurement is automatically recognized in comparison with the reference pattern, Since the frequency division ratio M, which is an integer multiple of the number of bits N of the data length, can be acquired, error rate measurement and waveform observation of the signal under measurement can be performed even if the pattern period of the signal under measurement is unknown in advance. It can be carried out.

  Even when a signal under measurement having an unknown pulse pattern is input from the device under test, the number of bits of the signal under measurement is counted to automatically recognize the data length of the bit string, and the number of bits N of the data length Since the division ratio M that is an integer multiple can be acquired, even when the pattern period of the signal under measurement is unknown in advance, the error rate measurement and waveform observation of the signal under measurement can be performed.

It is a schematic block diagram which shows the apparatus outline of the error rate measuring apparatus of the 1st form which concerns on this invention. It is a block diagram which shows the detailed structure of the data analysis part in the same apparatus. It is a conceptual diagram which shows the clock delay control by a delay control means. It is a schematic block diagram which shows the apparatus outline of the error rate measuring apparatus of the 2nd form which concerns on this invention. It is a block diagram which shows the detailed structure of the data analysis part in the same apparatus. It is a schematic block diagram which shows the structure of the conventional error rate measuring apparatus.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited by this embodiment, and all other forms, examples, operation techniques, etc. that can be implemented by those skilled in the art based on this form are included in the scope of the present invention. .

[First form]
First, an error rate measuring apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

<Device configuration>
As shown in FIG. 1, the error rate measuring apparatus 1 of the first embodiment is roughly configured to include a reference pattern generation unit 10, an error rate detection unit 20, a clock control unit 30, and a waveform observation unit 40, and a device under test 50. Is an apparatus for measuring the error rate of the signal under measurement (NRZ signal) input via the, and observing the waveform of the input signal to evaluate the performance of the device under test 50.

  The device under test 50 includes a reference pattern group composed of a plurality of reference patterns (for example, a plurality of preset PRBS patterns (Pseudorandom Binary (Bit) Sequence patterns)) and an arbitrary pattern arbitrarily set by the user. A reference pattern from a pulse pattern generator 60 having a function of a pulse pattern generator (PPG) that transmits a test signal of a known pulse pattern arbitrarily selected from A test signal based on is output.

  In order to calculate the error rate of the device under test 50, the reference pattern generator 10 outputs a reference pattern to be compared to an error rate calculation means 22a described later. In addition, when the reference pattern switching unit 10 receives a reference pattern switching signal from a synchronization determination unit 22b described later, the reference pattern generation unit 10 selects a reference pattern that is not compared from the reference pattern group and outputs it to the error rate calculation unit 22a. Yes. Further, when the reference pattern selection unit 10 receives the reference pattern selection signal from the synchronization determination unit 22b, the reference pattern generation unit 10 outputs a reference pattern corresponding to the signal to the error rate calculation unit 22a.

  The error rate detection unit 20 includes a data identification unit 21 and a data analysis unit 22, and inputs a test signal transmitted from the pulse pattern generation unit 60 as a signal under measurement via the device under test 50. It has the function of an error rate detector (ED) that detects the error rate of the signal.

  The data identification unit 21 identifies a signal level (High / Low) pattern in the signal under measurement based on the clock timing of the recovered clock input from the clock control unit 30, and the data analysis unit 22 uses this identified pattern as identification pattern data. Is output.

  As shown in FIG. 2, the data analysis unit 22 includes an error rate calculation unit 22a, a synchronization determination unit, and a data length detection unit 22c. The data analysis unit 22 analyzes the identification pattern data input from the data identification unit 21, M frequency division information indicating a frequency division ratio M (M is a natural number) used when the signal to be measured is frequency-divided by the M frequency dividing means 32 described later is output.

  The error rate calculation unit 22a calculates the error rate by comparing the identification pattern data input from the data identification unit 21 with the reference pattern output from the reference pattern generation unit 10, and uses the calculated error rate as a synchronization determination unit. To 22b.

The synchronization determination unit 22b compares the error rate calculated by the error rate calculation unit 22a with a reference error rate threshold set in advance, and determines whether the pattern is synchronized with the reference pattern compared by the error rate calculation unit 22b. Judging. When the calculated error rate falls below the reference error rate threshold as a result of the determination, the synchronization determination unit 22b determines that the compared reference pattern and the signal under measurement are pattern-synchronized, and the determination result is used as the data length detection unit. 22c. Further, when the calculated error rate exceeds the reference error rate threshold value as a result of the comparison, the synchronization determination unit 22b determines that the compared reference pattern and the signal under measurement are not pattern-synchronized, and other reference patterns The reference pattern switching signal for calculating the error rate again is output to the reference pattern generation unit 10 in comparison with.
That is, in the comparison determination in the synchronization determination unit 22b, when the calculated error rate exceeds the reference error rate threshold, it is not a comparison target from the reference pattern group until the calculated error rate falls below the reference error rate threshold. Comparison discrimination is performed by sequentially switching to the reference pattern.

  Note that the synchronization determination unit 22b compares all the error rates calculated by the error rate calculation unit 22a with all the reference patterns in the above-described reference pattern group when comparing the error rate calculated by the error rate calculation unit 22a with the reference error rate. When the threshold value is exceeded, the reference pattern selection signal for requesting the corresponding reference pattern is output to the reference pattern generation unit 10 in order to calculate the error rate again using the reference pattern having the lowest error rate error.

  The data length detection unit 22c provides information on the frequency division ratio M, which is an integral multiple of the number of bits N (N is a natural number) of the reference pattern that is pattern-synchronized with the signal under measurement based on the determination result notification input from the synchronization determination unit 22b. It is output to the clock control unit 30 as peripheral information.

  The clock control unit 30 includes a clock reproduction unit 31 and an M frequency division unit 32. The clock control unit 30 performs clock reproduction from a signal under measurement input via the device under test 50, and performs M division on the waveform observation unit 40. It outputs the clock that is around.

  The clock recovery means 31 extracts a clock synchronized with the pattern period of the signal under measurement input via the device under test 50 and outputs the extracted clock to the error rate detection unit 20 and the M frequency dividing means 32 as a recovered clock. doing.

  The M frequency dividing means 32 divides the frequency of the recovered clock input from the clock recovery means 31 based on the M frequency division information output from the data analysis unit 22, and outputs the M frequency divided clock to the waveform observation unit 40. doing.

  The waveform observation unit 40 includes a delay control unit 41, a sampling unit 42, an A / D conversion unit 43, and a waveform display unit 44. For example, the waveform observation unit 40 converts an analog measurement waveform such as a sampling oscilloscope into a digital signal and converts it into waveform data. And a waveform observer function that reproduces and displays a waveform image on the display screen based on waveform data obtained by discretely sampling events in which voltage and current values change over time. .

  As shown in FIG. 3, the delay control means 41 has a delay time ΔT (for example, several femtoseconds) arbitrarily set based on the frequency band to be measured and the sampling clock frequency. The amount of deviation is arbitrary) and is output to the sampling means 42 and the A / D conversion means 43 as sampling clocks that are shifted by one. In this way, by shifting the M-divided clock as a trigger from the sampling start point by an arbitrary delay time ΔT, the signal under measurement to be sampled can be sampled once.

  The sampling means 42 samples the signal under measurement at the clock timing of the sampling clock input from the delay control means 41 and outputs the sampled sampling signal to the A / D conversion means 43.

  The A / D conversion means 43 converts the sampling signal (analog signal) into a digital signal at the clock timing of the sampling clock input from the delay control means 41 and outputs it to the waveform display means 44.

  The waveform display means 44 controls the display (not shown) of the signal waveform of the sampling signal digitally converted by the A / D conversion means 43 in a display form desired by the user.

<Processing operation>
Next, the processing operation in the error rate measuring apparatus 1 described above will be described. Here, a processing operation when transmitting a test signal having a known pattern in advance to the device under test 50 and performing error rate measurement and waveform observation of the signal under measurement input via the device under test 50 will be described.

  First, a test signal having a known pulse pattern arbitrarily selected by the user is generated by the pulse pattern generator 60 and transmitted to the device under test 50. The error rate detection unit 20 inputs the transmitted test signal as a signal under measurement via the device under test 50.

  Next, the signal level of the signal under measurement input based on the recovered clock input from the clock control unit 30 is identified, and the identification pattern data as the identification result and the reference pattern group held by the reference pattern generation unit 10 are arbitrarily selected. The error rate is calculated by comparing with the selected reference pattern. Then, the calculated error rate is compared with a preset reference error rate threshold value.

At this time, when the calculated error rate falls below the reference error rate threshold, it is determined that the reference pattern to be compared and the signal under measurement are pattern-synchronized, and the reference that is pattern-synchronized with the signal under measurement is determined based on the determination result. The division ratio M is obtained by multiplying the bit number N (N is a natural number) of the pattern by an integer.
On the other hand, when the calculated error rate exceeds the reference error rate threshold, it is determined that the reference pattern to be compared and the signal under measurement are not in pattern synchronization, and the error rate is set again by switching to another reference pattern. calculate.

  The waveform observation unit 40 divides the recovered clock of the signal under measurement by M based on the M division information indicating the division ratio M acquired by the error rate detection unit 20. The M-divided clock is a sampling clock shifted by an arbitrarily set delay time, and the signal under measurement is sampled at the clock timing. After the sampled sampling signal is converted into a digital signal at the clock timing of the sampling clock, the signal waveform of the digitally converted sampling signal is displayed and controlled.

[Second form]
Next, an error rate measuring apparatus 1 according to a second embodiment of the present invention will be described with reference to FIGS. Note that in the error rate measuring apparatus 1 of the second embodiment described below, the same constituent elements as those of the error rate measuring apparatus 1 of the first embodiment described above are denoted by the same reference numerals, description thereof is omitted, and is different. Only the configuration requirements are described.

  As shown in FIGS. 4 and 5, the error rate measuring apparatus 1 according to the second embodiment uses bit string data in the input signal under measurement even when the pulse pattern of the signal under measurement input from the device under test 50 is unknown. A data analysis unit 22 capable of detecting the length is provided, and the apparatus configuration is configured to enable error rate measurement and input signal waveform observation.

<Device configuration>
As shown in FIG. 5, the data analysis unit 22 in the error rate measurement apparatus 1 of the second embodiment includes a head pattern holding unit 22d, a coincidence determination unit 22e, a bit number counting unit 22f, and a data length detection unit 22c. I have.

  When the identification pattern data from the data identification unit 21 is input, the head pattern holding unit 22d holds a part or all of the input identification pattern data and also sends a data holding start signal indicating the start of data holding to the coincidence determining unit. 22e and the bit number counting means 22f. The head pattern holding means 22d determines the first input pattern data that has started holding the identification data pattern as the head pattern.

  When the coincidence determination means 22e receives the data holding start signal from the head pattern holding means 22d, the head pattern held until the identification pattern data goes around once and matches the head pattern again and the identification pattern inputted from the data identification section 21 Compare the data. Then, as a result of the comparison, when the input identification pattern data and the head pattern match, the coincidence determination unit 22e outputs a count end signal for ending the bit number count to the bit number counting unit 22f.

  When the data holding start signal from the head pattern holding means 22d is input, the bit number counting means 22f starts counting the number of bits in order from the head pattern of the identification pattern data based on the reproduction clock input from the clock controller 30. When the bit number counting means 22f receives the count end signal from the coincidence determining means 22e, the bit number counting means 22f finishes counting the number of bits, outputs bit number data indicating the bit count number to the data length detection means 22c, and then counts. Reset the number.

  The data length detection unit 22c outputs information on the frequency division ratio M obtained by multiplying the bit number N (N is a natural number) of the bit number data input from the bit number counting unit 22f to the clock control unit 30 as M division information. ing.

<Processing operation>
Next, the processing operation in the error rate measuring apparatus 1 according to the second embodiment described above will be described. Here, a processing operation when performing error rate measurement and waveform observation of a signal under measurement having an unknown pulse pattern input via the device under test 50 will be described.

  The error rate detection unit 20 inputs the signal under measurement having an unknown pulse pattern via the device under test 50. Next, the signal level of the signal under measurement input based on the reproduction clock input from the clock control unit 30 is identified. Then, a part or all of the identification pattern data as the identification result is held, and counting of the number of bits is started in order from the head pattern of the identification pattern data.

  Next, until the identification pattern data goes around once and matches the head pattern again, the held head pattern is compared with the identification pattern data input from the data identification unit 21, and the input identification pattern data matches the head pattern. At that point, the bit count is finished. Then, the counted bit number N (N is a natural number) is multiplied by an integer to obtain the frequency division ratio M.

  The waveform observation unit 40 divides the recovered clock of the signal under measurement by M based on the M division information indicating the division ratio M acquired by the error rate detection unit 20. The M-divided clock is a sampling clock shifted by an arbitrarily set delay time, and the signal under measurement is sampled at the clock timing. After the sampled sampling signal is converted into a digital signal at the clock timing of the sampling clock, the signal waveform of the digitally converted sampling signal is displayed and controlled.

  As described above, the error rate measuring apparatus 1 according to the first embodiment described above identifies the signal level of the signal under measurement, which is a known pulse pattern input via the device under test 50, and indicates the identification result. The error rate is calculated by comparing the pattern data with the reference pattern held by the reference pattern generator 10. Next, the calculated error rate is compared with a preset reference error rate threshold, and when the calculated error rate falls below the reference error rate threshold, the number of bits N ( N is a natural number) multiplied by an integer to obtain a frequency division ratio M.

  Then, the waveform observing unit 40 divides the reproduction clock of the signal under measurement by M based on the M division information indicating the division ratio M, and then uses the clock timing as a sampling clock shifted by an arbitrarily set delay time. The signal under measurement is sampled and the sampling signal is converted into a digital signal at the clock timing of the sampling clock, and then the signal waveform of the sampling signal is displayed and controlled on the waveform display means 44.

  As a result, when a signal under measurement having a known pulse pattern is input from the device under test 50, the data length of the bit string in the signal under measurement is automatically recognized, and a frequency division ratio M that is an integral multiple of the pattern period is obtained. Therefore, even when the pattern period of the signal under measurement is unknown in advance, the error rate measurement and waveform observation of the signal under measurement can be performed.

  Further, in the error rate measuring apparatus 1 of the second embodiment, the signal level of the signal under measurement which is an unknown pulse pattern input via the device under test 50 is identified, and a part of the identification pattern data indicating the identification result or All are held, and counting of the number of bits is started in order from the head pattern of the identification pattern data. After the start of counting the number of bits, until the identification pattern data goes around once and coincides with the head pattern again, the held head pattern is compared with the identification pattern data input from the data identification unit 21, and the input identification pattern data and the head pattern are compared. When the number of bits coincides, the counting of the number of bits is terminated, and the counted number of bits N (N is a natural number) is multiplied by an integer to obtain a frequency division ratio M.

  Then, the waveform observing unit 40 divides the reproduction clock of the signal under measurement by M based on the M division information indicating the division ratio M, and then uses the clock timing as a sampling clock shifted by an arbitrarily set delay time. The signal under measurement is sampled and the sampling signal is converted into a digital signal at the clock timing of the sampling clock, and then the signal waveform of the sampling signal is displayed and controlled on the waveform display means 44.

  Thus, even when a signal under measurement having an unknown pulse pattern is input from the device under test 50, a frequency division ratio that automatically recognizes the data length of the bit string in the signal under measurement and is an integer multiple of the pattern period Since M can be acquired, even when the pattern period of the signal under measurement is unknown in advance, the error rate measurement and waveform observation of the signal under measurement can be performed.

  By the way, in the first embodiment described above, the error rate measurement and waveform relating to the signal under measurement transmitted in advance by transmitting the known test signal generated by the pulse pattern generator 60 to the device under test 50. Although it has been described that the observation is performed, since the pulse pattern of the signal under measurement may be a known pulse pattern in advance, for example, a test signal with a known pulse pattern is transmitted from the outside to the device under test 50 in advance. A configuration in which a signal input via the test device 50 is a signal under measurement may be used. At this time, a reference pattern used when calculating the error rate in the data analysis unit 22 is also input from the outside.

DESCRIPTION OF SYMBOLS 1 ... Error rate measuring device 10 ... Reference pattern generation part 20 ... Error rate detection part 21 ... Data identification part 22 ... Data analysis part (22a ... Error rate calculation means, 22b ... Synchronization determination means, 22c ... Data length detection means, 22d (... Lead pattern holding means, 22e ... Match determination means, 22f ... Bit number counting means)
DESCRIPTION OF SYMBOLS 30 ... Clock control part 31 ... Clock reproduction | regeneration means 32 ... M frequency division means 40 ... Waveform observation part 41 ... Delay control means 42 ... Sampling means 43 ... A / D conversion means 44 ... Waveform display means 50 ... Device under test 60 ... Pulse Pattern generator

Claims (5)

An error rate having an error rate detector (20) for detecting a bit error rate of a signal under measurement input via the device under test (50), and a waveform observation unit (40) for observing the waveform of the signal under measurement. A measuring device (1) comprising:
The error rate detector is
A data identification unit (21) for identifying a signal level pattern of the signal under measurement based on a clock timing of a reproduction clock synchronized with a bit rate of the signal under measurement, and outputting the identified pattern as identification pattern data;
An error rate calculated by comparing the identification pattern data input from the data identification unit with a reference pattern to be compared for calculating an error rate of the identification pattern data, and a degree of pattern synchronization A reference error rate threshold value is compared, and when the error rate falls below the reference error rate threshold value, information on a frequency division ratio M obtained by multiplying the number N of bits of the reference pattern synchronized with the signal under measurement by an integer is obtained. A data analysis unit (22) for outputting to the waveform observation unit as M frequency division information;
An error rate measuring apparatus comprising: An error having an error rate detector (20) for detecting the bit error rate of the signal under measurement input via the device under test (50) and a waveform observation unit (40) for observing the waveform of the signal under measurement. A rate measuring device (1),
The error rate detector is
A data identification unit (21) for identifying a signal level pattern of the signal under measurement based on a clock timing of a reproduction clock synchronized with a bit rate of the signal under measurement, and outputting the identified pattern as identification pattern data;
While holding the first input pattern data among the identification pattern data input from the data identification unit as a head pattern , comparing the identification pattern data and the head pattern while counting the number of bits of the identification pattern data, Information of the division ratio M, which is an integer multiple of the number N of bits of the identification pattern data counted until the identification pattern data makes a round and again coincides with the head pattern, is output to the waveform observation unit as M division information. A data analysis unit (22);
An error rate measuring apparatus comprising: When comparing the calculated error rate with the reference pattern, the data analysis unit (22) calculates the error rate when comparing all reference patterns in a reference pattern group composed of a plurality of reference patterns. 2. The error rate measuring apparatus according to claim 1, wherein when the reference error rate threshold value is exceeded, the error rate is calculated again using the reference pattern that has the lowest error rate error. An error having an error rate detection step of detecting a bit error rate of a signal under measurement input via the device under test (50) and a waveform observation step of observing the waveform of the signal under measurement by a waveform observation unit (40). A rate measuring method,
The error rate detection step includes:
A data identification step of identifying a signal level pattern of the signal under measurement based on a clock timing of a reproduction clock synchronized with a bit rate of the signal under measurement, and outputting the identified pattern as identification pattern data;
To determine the error rate calculated by comparing the identification pattern data output from the data identification step with a reference pattern to be compared for calculating the error rate of the identification pattern data, and the degree of pattern synchronization When the error rate falls below the reference error rate threshold, information on the frequency division ratio M obtained by multiplying the number N of bits of the reference pattern synchronized with the signal under measurement by an integer A data analysis step of outputting to the waveform observation unit as M frequency division information;
An error rate measurement method comprising: An error rate having an error rate detection step for detecting a bit error rate of a signal under measurement input via the device under test (50), and a waveform observation step for observing the waveform of the signal under measurement in a waveform observation unit (40). A measuring method,
The error rate detection step includes:
A data identification step of identifying a signal level pattern of the signal under measurement based on a clock timing of a reproduction clock synchronized with a bit rate of the signal under measurement, and outputting the identified pattern as identification pattern data;
Holds the first input pattern data of the identification pattern data output from the data identification step as the head pattern, comparing said identification pattern data and the top pattern while counting the number of bits of the identification pattern data , Information on the frequency division ratio M, which is an integer multiple of the number N of bits of the identification pattern data counted until the identification pattern data circulates once and coincides with the head pattern again, is output to the waveform observation unit as M frequency division information Data analysis step to perform,
An error rate measurement method comprising:

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