Error measuring device and error measuring method

Abstract

This invention provides an error measurement device and an error measurement method that can display a reliability level in accordance with the measurement conditions when executing a matrix scan function. [Solution] The error measurement device displays a matrix scan display screen 40 that displays information related to the matrix scan function. The matrix scan display screen 40 includes a spin box 44 for inputting the measurement time of the signal under test, spin boxes 52a and 52b for inputting the tolerance value of the error rate of the signal under test, a spin box 53 for inputting the tolerance value of the number of errors during the measurement time of the signal under test, and a text box 51 for displaying the reliability level. The error measurement device calculates the reliability level based on the data rate of the signal under test and the measurement time, the tolerance value of the error rate, and the tolerance value of the number of errors input into the matrix scan display screen 40.

Description

[Technical Field]

[0001] The present invention relates to an error measurement device and an error measurement method, which, during link training in a state where the device under test (DUT) is in a signal pattern folding state, transmits a test signal to the DUT based on parameter values ​​defined, for example, by the PCI Express 6.0 standard (hereinafter also referred to as the PCIe Gen6 standard), receives the signal under test folded back from the DUT in conjunction with the transmission of the test signal, and measures the number of errors and the error rate of the signal under test. [Background technology]

[0002] Error measurement devices are conventionally known as devices that measure the number of errors and error rate of the signal under test by sending a test signal of a known pattern containing fixed data to the DUT, and comparing the signal under test, which is received back from the DUT in conjunction with the transmission of the test signal, with a reference signal on a bit-by-bit basis.

[0003] For example, when testing whether a DUT (Device Under Test) complies with communication standards such as PCI Express, the error measurement device performs emphasis adjustment of the DUT's output waveform during link training. To ensure communication quality between the error measurement device and the DUT (link partner), it is necessary to select the optimal combination of emphasis in the error measurement device's transmitter and equalizer in the DUT's receiver.

[0004] Therefore, a matrix scan function is used that scans the emphasis settings of the transmitter section of the error measurement device to find the optimal setting for the DUT's receiver section and automatically searches for the optimal setting for the DUT's receiver section (see, for example, Patent Document 1). The matrix scan function can perform many error measurements at once.

[0005] Here, the confidence level (CL) for the error rate of the signal under test is defined by the following equation (1). The confidence level represents the probability that the true error rate of the signal under test is less than the predefined target BER (Bit Error Rate).

[0006]

number

[0007] In equation (1), N: Bitrate [bit / s] × Measurement time [s] (Number of bits measured) BER S :Target BER E: Target number of errors That is the case. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2024-022235 [Overview of the project] [Problems that the invention aims to solve]

[0009] However, conventional error measurement devices, such as the one disclosed in Patent Document 1, were not configured to display the reliability level, which is in line with the measurement conditions when the matrix scan function is executed, on the display screen along with the measurement results.

[0010] Therefore, conventionally, when performing the matrix scan function, there was a problem in that users had to perform cumbersome tasks themselves, such as opening a separate website or performing calculations, in order to know the reliability level that was appropriate for the measurement conditions.

[0011] The present invention has been made to solve such conventional problems, and an object thereof is to provide an error measurement device and an error measurement method capable of displaying a reliability level according to measurement conditions during execution of a matrix scan function.

Means for Solving the Problems

[0012] In order to solve the above problems, an error measurement device according to the present invention transmits a test signal based on parameter values of cells to be scanned, which are selected and set from a triangular matrix formed by combinations of coefficient values of C, C, and C in a Full Swing value defined by the PCI Express standard, to a DUT (100) during link training, receives a measured signal reflected from the DUT along with transmission of the test signal, and measures the number of errors and error rate of the measured signal, and is an error measurement device (1) that executes a matrix scan function. The coefficient values of C are selectably displayed by a number of tabs corresponding to the Full Swing value, and each combination of the coefficient value of C of the selected tab, each coefficient value of C, and each coefficient value of C is matrix-displayed on a display screen as the cell. With C as the horizontal coordinate axis, C as the vertical coordinate axis, and C as the depth direction coordinate axis, C, C, C -2 、C -1 、C +1 の各係数値の組み合わせによる三角行列マトリックスの中から選択設定されるスキャン対象のセルのパラメータ値に基づくテスト信号をリンクトレーニング中に被測定物(100)に送信し、前記テスト信号の送信に伴って前記被測定物から折り返される被測定信号を受信して、前記被測定信号のエラー数とエラーレートを測定するマトリックススキャン機能を実行する誤り測定装置(1)であって、前記Full Swing値に応じた数のタブにより前記C -2 の係数値を選択可能に表示し、選択したタブの前記C -2 の係数値と前記C +1 の各係数値と前記C -1 の各係数値との組み合わせの一つ一つを前記セルとして表示画面上にマトリックス表示するとともに、前記C +1 を横方向座標軸、前記C -1 を縦方向座標軸、前記C -2 を奥行き方向座標軸として、前記C -2 、前記C -1 、前記C +1 It should be noted that the content contains some unclear or potentially incorrect notations in the original text, which may affect the accuracy of the translation. It is recommended to check and clarify the original text for more precise translation.The system comprises a display control unit (17) that displays the matrix in a three-dimensional overhead view on the display screen, an operation display unit (32) that selects and sets a range including at least one of the cells to be scanned in the matrix display or the overhead view, a control unit (15) that executes the matrix scan function based on the parameter values ​​of the range selected and set by the operation display unit, an error measurement unit (14) that measures the number of errors and the error rate of the signal under test over a predetermined measurement time, and a reliability level calculation unit (20) that calculates a reliability level related to the allowable value of the error rate of the signal under test, wherein the display screen is, The reliability level calculation unit includes a measurement time input unit (44) for inputting the measurement time of the signal under test, a target error rate input unit (52a, 52b) for inputting an acceptable value for the error rate of the signal under test, a target error count input unit (53) for inputting an acceptable value for the number of errors during the measurement time of the signal under test, and a reliability level display unit (51) for displaying the reliability level. The reliability level calculation unit is configured to calculate the reliability level based on the data rate of the signal under test and the measurement time, the acceptable value for the error rate, and the acceptable value for the number of errors, which are input to the display screen.

[0013] With this configuration, the error measurement device according to the present invention displays a reliability level that corresponds to the measurement conditions during the execution of the matrix scan function on the display screen where the measurement conditions during the execution of the matrix scan function are set. As a result, the error measurement device according to the present invention eliminates the need for the user to separately open a website or the like to calculate the reliability level themselves.

[0014] Furthermore, in the error measurement device according to the present invention, the reliability level calculation unit substitutes the product of the data rate and the measurement time into N in the following formula (2), and the allowable value of the error rate is calculated in the following formula (2) ER S The reliability level may be calculated by substituting the values ​​into the equation and substituting the allowable number of errors into E in the following equation (2).

number

[0015] Furthermore, the error measurement device according to the present invention may further include a result output unit (21) that outputs the allowable value of the error rate, the allowable value of the number of errors, and the reliability level displayed on the display screen in a predetermined file format.

[0016] With this configuration, the error measurement device according to the present invention outputs various measurement conditions, including the allowable error rate of the signal under measurement, the allowable number of errors, and the reliability level, displayed on the display screen, in a predetermined file format. As a result, even at a later date after the matrix scan function has been executed, the user can confirm the reliability level in accordance with the measurement conditions at the time the matrix scan function was executed.

[0017] Furthermore, the error measurement method according to the present invention relates to the C value in the Full Swing value as defined in the PCI Express standard. -2 , C -1 , C +1 An error measurement method that performs a matrix scan function to measure the number of errors and error rate of the measured signal, wherein the number of tabs corresponding to the Full Swing value of the C -2 Step (S1) displays the coefficient value of the selected tab C -2 The coefficient value and the C +1 Each coefficient value and the C -1 Step (S1) displays each combination of each coefficient value as a cell in a matrix on the display screen, and C +1 The horizontal coordinate axis, C -1 The vertical coordinate axis, and the C -2 Using the depth coordinate axis, the C -2 , said C -1 , said C +1The steps include: (S1) displaying the matrix in a three-dimensional overhead view on the display screen; (S2) selecting and setting a range that includes at least one of the cells to be scanned in the matrix display or the overhead view; (S3) calculating a reliability level for the allowable value of the error rate of the signal under test; (S4) displaying the reliability level on the display screen; and (S5-S7) executing the matrix scan function based on the parameter values ​​of the selected range, wherein the step of executing the matrix scan function measures the number of errors and the error rate of the signal under test over a predetermined measurement time. The system includes an error measurement step (S7) to determine the reliability level, and the display screen includes a measurement time input unit (44) for inputting the measurement time of the signal under test, a target error rate input unit (52a, 52b) for inputting an acceptable value for the error rate of the signal under test, a target error count input unit (53) for inputting an acceptable value for the number of errors during the measurement time of the signal under test, and a reliability level display unit (51) for displaying the reliability level, wherein the reliability level calculation step calculates the reliability level based on the data rate of the signal under test and the measurement time, the acceptable value for the error rate, and the acceptable value for the number of errors, which are input to the display screen. [Effects of the Invention]

[0018] The present invention provides an error measurement device and an error measurement method that can display a reliability level in accordance with the measurement conditions when executing a matrix scan function. [Brief explanation of the drawing]

[0019] [Figure 1] This is a block diagram showing the configuration of an error measuring device according to an embodiment of the present invention. [Figure 2] This figure shows the matrix scan display screen when the [Measurement] tab is selected in the error measurement device according to the present invention. [Figure 3]This figure shows the matrix scan display screen when the [Starting Preset] tab is selected in the error measurement device according to the present invention. [Figure 4] This figure shows the matrix scan display screen when the [Scan] tab is selected in the error measurement device according to the present invention. [Figure 5] This figure shows an example of a matrix scan editing screen in the error measurement device according to the present invention. [Figure 6] This figure shows an example of the contents of a file output from the result output unit of the error measurement device according to the present invention. [Figure 7] This flowchart shows the process of an error measurement method using an error measurement device according to an embodiment of the present invention. [Figure 8] This figure shows a preset table of coefficient values ​​defined in the PCIe Gen6 standard. [Modes for carrying out the invention]

[0020] Hereinafter, embodiments of the error measuring device and error measuring method according to the present invention will be described with reference to the drawings.

[0021] [Summary of the present invention] The error measurement device according to the present invention uses a device compliant with the PCIe Gen6 standard as shown in PCI Express Base Specification Revision 6.0 16 December 2021 as the device under test (DUT), for example, as a connection standard for expansion buses and expansion slots. During link training in which the DUT is in a signal pattern folding state, a test signal based on parameter values ​​defined in the PCIe Gen6 standard is sent to the DUT, and the number of errors and error rate of the signal under test that is folded back from the DUT upon transmission of this test signal are measured.

[0022] Furthermore, section 8.3.3 Tx Equalization Presets for 8.0, 16.0, 32.0, 1, and 64.0 GT / s of the PCIe Gen6 standard includes descriptions of emphasis preset values, as shown in Figure 8-6 Definition of Tx Voltage Levels and Equalization Ratios, Table 8-1 Tx Preset Ratios and Corresponding Coefficient Values ​​for 8.0, 16.0, and 32.0 GT / s, and Table 8-2 Tx Preset Ratios and Corresponding Coefficient Values ​​for 64.0 GT / s (see Figure 8).

[0023] Furthermore, section 8.3.3.8 Coefficient Range and Tolerance for 8.0, 16.0, 32.0, 1, and 64.0 GT / s of the PCIe Gen6 standard includes a description of a triangular matrix table, as shown in Figure 8-10 Transmit Equalization Coefficient Space Triangular Matrix Example for 64.0 GT / s.

[0024] The matrix scan function described above refers to the C value in the Full Swing value (one of 24, 48, or 63) as defined by the PCIe Gen6 standard. -2 , C -1 , C +1 This function automatically searches for the optimal settings for the DUT's receiver by sequentially sending test signals to the DUT during link training, based on the parameter values ​​of the cells to be scanned, selected from a triangular matrix mapped by combinations of coefficient values, and receiving the measured signal folded back from the DUT in conjunction with this transmission, and measuring the number of errors and error rate of the measured signal.

[0025] As shown in Figure 1, the error measurement device 1 of this embodiment is generally configured to include a data transmission unit 10, a data reception unit 12, a control unit 15, a data storage unit 30, and an operation display unit 32.

[0026] As shown in Figure 1, the DUT100 is generally configured to include a control unit 110, a data receiving unit 120, and a data transmitting unit 130. The configuration of the DUT100 and the error measuring device 1 will be described below with reference to the drawings.

[0027] [Regarding the composition of the object being measured] The control unit 110 includes a link status management mechanism (LTSSM (Link Training and Status State Machine)) 111, which manages the link status and provides overall control of the data receiving unit 120 and the data transmitting unit 130 when performing error measurement.

[0028] When performing error measurement, the data receiving unit 120 receives the test signal transmitted from the data transmitting unit 10 of the error measurement device 1 while in a state where the signal pattern is folded back, also known as loopback, under the control of the control unit 110.

[0029] The data receiving unit 120 is equipped with an equalizer 121 that can be set arbitrarily by the user. The equalizer 121 adjusts the frequency characteristics of the test signal received from the data transmitting unit 10 of the error measurement device 1 to improve reception sensitivity.

[0030] When performing error measurement, the data transmission unit 130, under the control of the control unit 110, transmits a response signal to the received test signal as the signal to be measured back to the error measurement device 1 when the data reception unit 120 receives a test signal from the data transmission unit 10 of the error measurement device 1.

[0031] [Regarding the configuration of the error measurement device] The operation display unit 32 consists of a graphical user interface (GUI) that combines the functions of both an operation unit, such as a mouse, for inputting various information related to error measurement, and a display unit for displaying screens related to error measurement settings and measurement results.

[0032] The operation display unit 32 displays the matrix scan display screen 40 in the display format shown in Figure 2. A "Start" soft key 41, which is pressed when executing the matrix scan function, is provided in the upper right corner of the matrix scan display screen 40 in Figure 2. The matrix scan display screen 40 consists of a parameter setting display area 42 for making the necessary settings to execute the matrix scan function, and a measurement result display area 43 for displaying the measurement results when the matrix scan function is executed.

[0033] The operation display unit 32 sets various measurement conditions necessary to execute the matrix scan function in the parameter setting display area 42 of the matrix scan display screen 40 in Figure 2. These various settings are made by selecting one of the following tabs in the parameter setting display area 42: [Measurement] tab 42a, [Starting Preset] tab 42b, or [Scan] tab 42c.

[0034] First, let's explain what happens when you select the [Measurement] tab 42a in the parameter setting display area 42 of Figure 2. In this case, the "BER Meas. Time [sec]" spin box 44 allows you to set the measurement time for error measurement of the signal under test with a setting range of 1 to 300 seconds and a step of 1 second / step. The "BER Meas. Time [sec]" spin box 44 constitutes a measurement time input section for inputting the measurement time of the signal under test.

[0035] Furthermore, the screen of the [Measurement] tab 42a includes a text box 51 labeled "Target CL", spin boxes 52a and 52b labeled "ER", and a spin box 53 labeled "Target EC".

[0036] Furthermore, the "Target CL" text box 51 contains the target reliability level CL calculated by the reliability level calculation unit 20, which will be described later. S This is displayed in a range, for example, from 0.0 to 99.9%. The text box 51 labeled "Target CL" is the target confidence level CL. S A reliability level display unit is configured to show the reliability level.

[0037] The "ER" spin boxes 52a and 52b target the error rate ER of the signal under test from the DUT100. s This section contains a target error rate input unit for inputting the target error rate ER. s This is the allowable value for the error rate of the signal under measurement in the error measurement by the error measurement unit 14.

[0038] Spin boxes 52a and 52b have a target error rate ER s The system allows input in exponential notation, with the mantissa being entered in spin box 52a and the exponent in spin box 52b. For example, spin boxes 52a and 52b can accept values ​​in the range of 1E-15 to 9E-3.

[0039] The "EC" spin box 53 allows input of the target number of errors E during the measurement time of the signal under test. For example, the spin box 53 can accept values ​​in the range of 0 to 10.

[0040] Next, we will explain what happens when you select tab 42b of the [Starting Preset] in the parameter setting display area 42 of Figure 3. In this case, pressing the "All ON" or "All OFF" button will select or deselect all of the initial preset settings for error measurement. Alternatively, pressing any of the "Q0" to "Q10" buttons will allow you to individually select or deselect the initial preset settings for error measurement. Note that the initial preset settings are performed as initial settings to adjust the behavior of each DUT100.

[0041] Next, we will explain what happens when you select the [Scan] tab 42c in the parameter setting display area 42 of Figure 4. In this case, under "FS (Full Swing)," you can set the Full Swing value of the matrix scan function by selecting from the pull-down menu values: 24, 48, and 63.

[0042] The "LF (Low Frequency)" field displays the Low Frequency calculated from the Full Swing value of the matrix scan function. Figure 4 shows the display of Low Frequency "8," which is calculated from a Full Swing value of "24."

[0043] In "Search Direction," you can set the scan direction by selecting from "Horizontal," "Vertical," and "Depth" in the pull-down menu. Figure 4 shows the state when "Horizontal" is selected.

[0044] In "Full Scan," you can configure this by checking checkbox 45 to perform a matrix scan on all cells. Note that when checkbox 45 for "Full Scan" is checked, "Scan Mode" will be grayed out.

[0045] In "Scan Mode," you can set the scanning method by selecting either "Start from Selected Cell" or "Scan Scenario" with the "Full Scan" checkbox (45) unchecked. Figure 4 shows the state when "Scan Scenario" is selected.

[0046] To the right of "Full Scan," the scan target is displayed in two formats: a 3D format (X: horizontal coordinate axis, Y: vertical coordinate axis, Z: depth coordinate axis) and a table format. In the 3D format display of the scan target, C +1 The horizontal coordinate axis (X-axis), C -1 The vertical coordinate axis (Y axis), C -2 Using the depth coordinate axis (Z axis), C -2 , C -1 , C +1 It displays a three-dimensional, bird's-eye view.

[0047] Furthermore, in the table format display of the scan target, a C appears above the 3D format display of the scan target. -2 Each coefficient value (0, 1, 2 in Figure 4) is displayed independently, C -2 For each coefficient value (0,1,2), the combination is C +1 Each coefficient value (0-8) is plotted on the horizontal axis (X-axis), C -1 The coefficient values ​​(0-6) are displayed as a matrix on the vertical axis (Y-axis). In both the 3D and table formats, the scan targets (Target) and non-scan targets (Non-target) are distinguished by color coding. For example, scan targets are displayed in green and non-scan targets in gray.

[0048] Here, the "Scenario Edit" button 49 located within the "Full Scan" section is operated when the "Start from Selected Cell" or "Scan Scenario" is selected while the "Full Scan" checkbox 45 is unchecked, and the matrix scan editing screen 60 shown in Figure 5 is called up.

[0049] The matrix scan editing screen 60 in Figure 5 is a screen for selecting the scan target, and the "FS (Full Swing) display" shows the currently selected FS setting. Figure 5 shows the case where the currently selected FS setting is "24". The operation display unit 32 displays the matrix scan editing screen 60 in Figure 5 and, as described below, selects a range that includes at least one cell to be scanned on the matrix scan editing screen 60.

[0050] At the top right of the matrix scan editing screen 60, an "Edit selection combo box" 61 is displayed for selecting the scan target to edit from a pull-down menu.

[0051] Furthermore, when a user changes the scan target, selecting the scan target can be difficult depending on the Full Swing value (for example, setting it to 63). To address this, in this embodiment, multiple scenarios (e.g., Scenario0 to 5) consisting of cells with different combinations of pre-edited parameter values ​​are provided, and can be selected from the pull-down menu of the "Edit Selection Combo Box" 61. Figure 5 shows the state where "Scenario0" is selected from the pull-down menu of the "Edit Selection Combo Box" 61. Note that the prepared scenarios may also include cells with parameter values ​​specified in the PCIe Gen6 standard (parameter values ​​of PresetQ0 to Q10 in Figure 8).

[0052] Below the "Edit Selection Combo Box" 61, several buttons are displayed vertically: "All ON," "All OFF," "ON," and "OFF." The "All ON" button is used to select all items to scan, and the "All OFF" button is used to deselect all items to scan. Additionally, the "ON" button is used to make the selected matrix a scan target, and the "OFF" button is used to remove the selected matrix from the scan target.

[0053] In the center of the matrix scan editing screen 60, the "Scan Target Selection Matrix" 62 is displayed for selecting cells to be scanned from the matrix using the mouse. Figure 5 shows the "Scan Target Selection Matrix" 62 when the Full Swing value is "24", C -2 :0,1,2,3 are displayed independently, C -2 :C for 0, 1, 2, 3 -1 :0~6,C +1 The combinations of 0 to 8 are displayed as a matrix. In the "Scan Target Selection Matrix" 62, selected cells, targets, and non-targets are displayed in different colors.

[0054] In Figure 5, C -2 :0,2 in (C -1 ,C +1 )=(2,1), (C -1 ,C +1 )=(2,2), (C -1 ,C +1 )=(3,1), (C -1 ,C +1 )=(3,2) is displayed in light blue (black area in Figure 5) as the selected cell, C -2 :0,2 in (C -1 ,C +1 )=(2,5), (C -1 ,C +1 )=(2,6), (C -1 ,C +1 )=(3,5), (C -1 ,C +1 )=(5,0), (C -1 ,C +1 )=(5,1), (C -1 ,C +1 )=(6,0), (C -1 ,C +1 The area )=(6,1) is displayed as the target in green (the upward-sloping diagonal line in Figure 5), while the remaining area is displayed as the non-target in gray (the white area in Figure 5).

[0055] On the left side of the "Scan Target Selection Matrix" 62, C -2A "Scan Target Diagram" 63 is displayed to represent the scan target in three dimensions. +1 The horizontal coordinate axis (X-axis), C -1 The vertical coordinate axis (Y axis), C -2 Using the depth coordinate axis (Z axis), C -2 , C -1 , C +1 Display it in a three-dimensional, overhead view, C -2 The scan targets are displayed in different colors. For example, C -2 Scan targets are displayed in green, and non-scan targets are displayed in gray. "Scan Target Diagram" 63 indicates which side is C -2 This displays in 3D whether an object is eligible for scanning.

[0056] The "OK" button located at the bottom right of the matrix scan editing screen 60 is used to save the editing results. The "Cancel" button to the right of the "OK" button is used to discard the editing results.

[0057] Furthermore, the operation display unit 32 allows selection of the test pattern that will be the basis for the test signal transmitted to the DUT 100 on a settings screen (not shown). The test pattern can be selected from PRBS (Pseudo Random Bit Sequence) and Compliance (a 1b / 1b encoded test pattern compliant with the PCIe Gen6 standard). Compliance can be further selected from MCP (Modified Compliance Pattern: a test pattern for BER measurement), CP (Compliance Pattern: a test pattern used for waveform calibration or Init Tx EQ.Tx LEQ Response Time Test), and Jitter Measurement Pattern (a 1,0 pattern for measuring jitter).

[0058] Figure 1 illustrates a configuration in which the operation display unit 32 combines the functions of both an operation unit for inputting various information and a display unit for displaying setting screens, measurement screens, etc. However, the operation display unit 32 may also be configured with the operation unit and display unit as separate components.

[0059] The data transmission unit 10 includes an emphasis control unit 11 that adjusts and controls the emphasis of the output waveform of the error measurement device 1. When the DUT 100 is in a loopback state and error measurement is performed on the DUT 100, the data transmission unit 10 generates a pattern signal as a test signal, which is a PRBS pattern or an arbitrary programmable pattern whose emphasis of the output waveform has been adjusted and controlled by the emphasis control unit 11, and transmits it to the DUT 100 as a known pattern to be input to the DUT 100.

[0060] The test signal is a signal that has been emphasized based on parameter values ​​consisting of a table of triangular matrices mapped from the coefficients of preset cursor values ​​defined in the PCIe Gen6 standard to the test pattern selected in the operation display unit 32.

[0061] To explain further, when the [Scan] tab 42c of the parameter setting display area 42 is selected, and one of the ranges 24, 48, or 63 is selected as the configurable range in FS (Full Swing), the data transmission unit 10 transmits all or a specified preset C defined in the PCIe Gen6 standard within the selected range. -2 , C -1 , C +1 Va, Vb, Vc1, Vc2, and Vd are calculated from the emphasis ratio (actually de-emphasis) based on PS2, PS1, DE, and Boost in the combination of these elements, and from the total amplitude value of the data transmission unit (signal generator) 10, and a test signal generated based on the calculation result is sent to the DUT100.

[0062] Here, PS2 represents Pre-Shoot2 (dB), PS1 represents Pre-Shoot1 (dB), and DE represents De-Emphasis (dB).

[0063] The data storage unit 30 is composed of memory such as RAM (Random Access Memory). The data storage unit 30 stores known pattern signal data that is input from the data transmission unit 10 to the DUT 100, such as bit sequence data (data consisting of a sequence of bits consisting of 0s or 1s) of NRZ (Non Return to Zero) type signals (hereinafter also simply referred to as "NRZ signals"), and symbol sequence data (data consisting of a sequence of symbols consisting of 0s, 1s, 2s, or 3s) of PAM4 (Pulse Amplitude Modulation 4) type signals (hereinafter also simply referred to as "PAM4 signals").

[0064] Furthermore, the data storage unit 30 may also store the bit sequence data of the MSB (Most Significant Bit) and LSB (Least Significant Bit) of the PAM4 signal input to the DUT 100. The symbol sequence data of the PAM4 signal, the bit sequence data of the MSB and LSB, and the bit sequence data of the NRZ signal stored in the data storage unit 30 also serve as reference data for the error measurement unit 14 to compare with the signal under measurement from the DUT 100.

[0065] When error measurement is performed, the data receiving unit 12 receives the signal to be measured, which is transmitted in return by the data transmitting unit 130 of the DUT 100 in conjunction with the transmission of the test signal, when the test signal from the data transmitting unit 10 is transmitted to the DUT 100.

[0066] The data receiving unit 12 includes an error measurement unit 14 that measures the number of errors and the error rate of the signal under measurement over a predetermined measurement period.

[0067] The error measurement unit 14 measures the number of errors and the error rate of the signal under test by sequentially comparing the bit sequence data or symbol sequence data contained in the signal under test with reference data stored in the data storage unit 30.

[0068] The error measurement unit 14 is configured to count the number of errors in the measured signal over the measurement time set by the spin box 44 of "BER Meas. Time [sec]" on the matrix scan display screen 40. Further, the error measurement unit 14 calculates the value obtained by dividing the counted number of errors by the number of measurement data of the measured signal over the above measurement time as the error rate of the measured signal.

[0069] Furthermore, the data storage unit 30 stores various setting information set by the operation display unit 32 when performing error measurement, the measurement results of error measurement, the editing results of scenarios on the matrix scan editing screen 60, and the like.

[0070] The data storage unit 30 stores parameter values consisting of a table of triangular matrix matrices mapped from each coefficient of preset cursor values defined by the PCIe Gen6 standard for each setting range (24, 48, 63) in order to generate a test signal when performing error measurement, and stores the correction formulas (A) to (D) of PS2, PS1, DE, and Boost shown below.

[0071] PS2 = (1 - 2×C +1 - 2×C -1 - 2×C -2 ) / (1 - 2×C +1 - 2×C -1 )... Correction formula (A) PS1 = (1 - 2×C +1 ) / (1 - 2×C +1 - 2×C -1 )... Correction formula (B) DE = (1 - 2×C +1 - 2×C -1 ) / (1 - 2×C -1 )... Correction formula (C) Boost = 1 / (1 - 2×C +1 - 2×C -1 )... Correction formula (D)

[0072] Here, the method of generating a test signal by the data transmission unit 10 will be described. The data transmission unit 10 is the C of the cell to be scanned.-2 , C -1 , C +1 The PS2, PS1, DE, and Boost values ​​are calculated using correction formulas (A) to (D) stored in the data storage unit 30. Note that the C of the cell to be scanned is... -2 , C -1 , C +1 The coefficient value can be determined from the Swing value / Full Swing value (one of 24, 48, or 63). For example, C -2 Regarding this, the coefficient value when Swing value = 2 and Full Swing value = 24 is 2 / 24 = 0.083333...

[0073] The data transmission unit 10 then calculates the emphasis (actually de-emphasis) ratio based on PS2, PS1, DE, and Boost: PS2 = 20log 10 (Vc2 / Vb), PS1=20log 10 (Vc1 / Vb), DE=20log 10 (Vb / Va), Boost=20log 10 Va, Vb, Vc1, Vc2, and Vd are calculated from (Vd / Vb) and the total amplitude value of the data transmission unit 10 (signal generator) (a value determined by DUT100), and a test signal with emphasis applied based on the above calculation results is generated for the test pattern selected by the operation display unit 32.

[0074] The control unit 15 is composed of a control device such as a computer, which includes, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an FPGA (Field Programmable Gate Array), ROM (Read Only Memory), RAM, and an HDD (Hard Disk Drive).

[0075] The control unit 15 comprehensively controls the data transmission unit 10, the data reception unit 12, the data storage unit 30, and the operation display unit 32 to execute the matrix scan function. Furthermore, for example, the control unit 15 configures the link status management unit 16, the display control unit 17, the transmission speed conversion unit 18, the reliability level calculation unit 20, and the result output unit 21 in software by executing a predetermined program by the CPU or GPU.

[0076] The link status management unit 16 has an LTSSM as the same or equivalent mechanism as the link status management unit 111 mounted on the DUT100, and operates in accordance with the PCIe Gen6 standard used.

[0077] To explain further, the link status management unit 16 recognizes the current link status of the DUT 100's link status management unit 111 based on the training patterns (TS1 Ordered Sets and TS2 Ordered Sets) communicated with the DUT 100 (data receiving unit 120, data transmitting unit 130). Specifically, the link status management unit 16 obtains various information such as link speed, presence or absence of loopback, lane number for lane identification, link number, pattern signal generation time and number of occurrences, emphasis amount, and equalizer adjustment value.

[0078] When the error measurement unit 14 performs error measurement, the display control unit 17 controls the operation display unit 32 to display various information and measurement results necessary for the control unit 15 to execute the matrix scan function, for example, as a matrix scan display screen 40 in the display format shown in Figures 2 to 4.

[0079] The transmission speed conversion unit 18 converts the known baud rate of the signal under test from the DUT 100 to a transmission speed (data rate) corresponding to the measurement unit of the signal under test. The baud rate of the signal under test may be set via a setting screen (not shown).

[0080] The data rate is a parameter that indicates the number of measurement units contained per second in the signal being measured. Measurement units can be, for example, bits, symbols (PAM4 Symbol), frits, or codewords.

[0081] Target Error Rate (ER) S This can be, for example, BER, SER (Symbol Error Rate), Uncorrectable Codeword Rate, or Flit Error Rate, and represents the upper limit of the error rate that can be tolerated for the signal being measured.

[0082] "Bit" is the unit of measurement when measuring the BER of the signal under test. When the unit of measurement is "Bit" and the signal under test is an NRZ signal, the transmission speed conversion unit 18 outputs the baud rate of the signal under test as the data rate. When the unit of measurement is "Bit" and the signal under test is a PAM4 signal, the transmission speed conversion unit 18 outputs a rate that is twice the baud rate of the signal under test as the data rate.

[0083] "PAM4 Symbol" is the unit of measurement when measuring the SER of the signal under test. When the unit of measurement is "PAM4 Symbol" and the signal under test is a PAM4 signal, the transmission speed conversion unit 18 outputs the baud rate of the signal under test directly as the data rate.

[0084] "Flit" is the unit of measurement used when measuring the Flit Error Rate of the signal under test. When the unit of measurement is "Flit," the transmission speed conversion unit 18 outputs a data rate obtained by doubling the baud rate of the signal under test and dividing it by the Flit length. Here, the Flit length is 2048 bits.

[0085] "Codeword" is the unit of measurement used when measuring the Uncorrectable Codeword Rate of a signal under test. When the unit of measurement is "Codeword," the transmission speed conversion unit 18 outputs a data rate obtained by doubling the baud rate of the signal under test and dividing it by the CW (Codeword) length. Here, the CW length is 5440 bits in the case of RS-FEC (Reed-Solomon Forward Error Correction) (544,514) as defined in IEEE 802.3.

[0086] The reliability level calculation unit 20 calculates the target error rate ER of the signal under test. s Target reliability level CL S The system is designed to calculate the reliability level, which is the target error rate (ER). S This represents the probability that the true error rate of the measured signal will be smaller than the given value.

[0087] Specifically, the reliability level calculation unit 20 substitutes the product of the data rate [data / s] output from the transmission speed conversion unit 18 and the measurement time [s] input to the spin box 44 of "BER Meas. Time [sec]" on the matrix scan display screen 40 into N in the following equation (2), and the target error rate ER input to the spin boxes 52a and 52b of "ER" on the matrix scan display screen 40. s The ER of the following equation (2) S Substitute the values ​​into the equation, and then substitute the target error count E entered into spin box 53 of "Target EC" into E in equation (2) below to obtain the target reliability level CL S Calculate.

[0088]

number

[0089] N is a parameter that indicates the number of measurement units included in the signal under measurement over the measurement time, i.e., the number of measurement data points.

[0090] Furthermore, the reliability level calculation unit 20 uses the number of errors measured by the error measurement unit 14 to calculate the target error rate ER s It is also possible to calculate the reliability level related to this.

[0091] Specifically, the reliability level calculation unit 20 substitutes the product of the data rate [data / s] output from the transmission speed conversion unit 18 and the measurement time [s] input to the spin box 44 of "BER Meas. Time [sec]" on the matrix scan display screen 40 into N in the following equation (3), and the target error rate ER input to the spin boxes 52a and 52b of "ER" on the matrix scan display screen 40. s The ER of the following equation (3) S Substitute the values ​​into the equation, and then substitute the number of errors measured by the error measurement unit 14 into E in equation (3) below to calculate the reliability level CL.

[0092]

number

[0093] The operation display unit 32 displays the measurement results when the matrix scan function is executed in the measurement result display area 43 of the matrix scan display screen 40 shown in Figures 2 to 4.

[0094] As shown in Figures 2 to 4, the measurement result display area 43 consists of a table display area 46 and a detail display area 47. The table display area 46 has a number of tabs corresponding to the Full Swing value (4 tabs if the Full Swing value is 24, 7 tabs if the Full Swing value is 48, and 9 tabs if the Full Swing value is 63) -2 The coefficient values ​​are displayed as selectable options.

[0095] Then, the table display area 46 is C of the selected tab. -2 The coefficient value and C +1 Each coefficient value and C -1 Each combination with each coefficient value, that is, C -2 The coefficient value and C+1 The coefficient value and C -1 Each combination of coefficient values ​​is treated as a cell, and the number of errors for each cell (EC in the table display area 46 of Figures 2 to 4) and the error rate (BER in the table display area 46 of Figures 2 to 4) when the matrix scan function is executed are displayed in a matrix, and the error rate for each cell is color-coded according to the degree of error.

[0096] Each cell displays the PS2, PS1, DE, and Boost values ​​calculated using correction formulas (A) to (D), along with the number of errors and the error rate. The error rate for each cell is color-coded according to the degree of error, such as Link fail, Auto Search Fail, Syncloss / Clock loss, BER≧1E-6, 1E-6>BER≧1E-7, 1E-7>BER≧1E-8, 1E-8>BER≧1E-10, 1E-10>BER≧1E-12, and Error free.

[0097] Furthermore, each cell contains the measurement time [s] entered into spin box 44 for "BER Meas. Time [sec]" and the target error rate ER entered into spin boxes 52a and 52b for "ER". s Then, the reliability level CL calculated by the reliability level calculation unit 20 based on the number of errors measured by the error measurement unit 14 is displayed.

[0098] Note that Figures 2 to 4 are C +1 Each coefficient value is plotted on the horizontal axis (X axis), C -1 The coefficient values ​​of each are displayed as a matrix with the vertical axis (Y axis), but C +1 Each coefficient value is plotted on the vertical axis (Y axis), C -1 The coefficient values ​​may also be displayed as a matrix with the horizontal axis (X-axis).

[0099] The detailed display area 47 displays thumbnail images of each cell, color-coded according to the degree of error. This thumbnail display is C -2 Each coefficient value (0, 1, 2, 3 in Figures 2-4) is displayed independently, and C-2 For each coefficient value (0, 1, 2, 3), the combination is C +1 Each coefficient value (0-8) is plotted on the horizontal axis (X-axis), C -1 Each coefficient value (0-6) is displayed as a matrix on the vertical axis (Y-axis). Furthermore, the thumbnail display in the detailed display area 47, similar to the display in the table display area 46, displays thumbnails of reduced images, color-coding the error rate of each cell according to the degree of error.

[0100] The matrix scan display screen 40 has C on the left side of the thumbnail display in the detailed display area 47. +1 The horizontal coordinate axis (X-axis), C -1 The vertical coordinate axis (Y axis), C -2 Using the depth coordinate axis (Z axis), C -2 , C -1 , C +1 This provides a three-dimensional overview of the newly added C by the PCI Express 6 standard. -2 By using the depth coordinate axis (Z-axis), it is possible to create a three-dimensional overhead view that takes advantage of the display capabilities of PCI Express 5.0 and earlier standards.

[0101] C in the overview view in the detailed display area 47 -2 In the vicinity of C -2 An input box 48a is provided for inputting the coefficient value by operating the increment / decrement keys. Similarly, C -1 In the vicinity of C -1 An input box 48b is provided for inputting the coefficient value by operating the increment / decrement keys, C +1 In the vicinity of C +1 An input box 48c is provided for inputting the coefficient value by operating the increment / decrement keys. Then, the C is determined by the values ​​entered in each input box 48a, 48b, 48c. -2 , C -1 , C +1 The portion corresponding to the coefficient value (the rectangular portion) is identified and displayed, for example, by coloring it green.

[0102] Note that in a three-dimensional overhead view, C +1 The coordinate axes and C-1 The coordinate axes are aligned with the matrix display. That is, Figures 2 to 4 are C +1 The horizontal axis (X-axis), C -1 Since it is displayed as a matrix with the vertical axis (Y axis), C +1 The horizontal coordinate axis (X-axis), C -1 This is used as the vertical coordinate axis (Y-axis).

[0103] The matrix scan display screen 40 is located below the overview display in the detailed display area 47, and the inputs C entered in the overview display input boxes 48a, 48b, and 48c are displayed. -2 , C -1 , C +1 The cell's BER (Error Rate), EC (Error Count), CL (Confidence Level) (%), PS2 (dB), PS1 (dB), DE (dB), and Boost (dB) are displayed based on the combination of coefficient values. Here, BER and EC are measured values ​​obtained by the error measurement unit 14, while PS2, PS1, DE, and Boost are calculated values ​​obtained by the data transmission unit 10.

[0104] Figures 2 to 4 are C -2 =1, C -1 =2, C +1 This example shows the BER, EC, CL(%), PS2(dB), PS1(dB), DE(dB), and Boost(dB) values ​​for a cell based on the combination of =1. For example, BER is 7.5E-13, EC is 300, CL(%) is 0.0, PS2(dB) is -1.0, PS1(dB) is 1.7, DE(dB) is -0.9, and Boost(dB) is 2.5.

[0105] The result output unit 21 displays the target error rate ER of the measured signal in the parameter setting display area 42 of the matrix scan display screen 40. s , target error count E, and target reliability level CL s The system is designed to output various measurement conditions, including those mentioned above, in a predetermined file format.

[0106] Furthermore, the results output unit 21 outputs the calculated values ​​of PS2, PS1, DE, and Boost, as well as the measured values ​​of EC and BER, and the reliability level CL based on EC, which are displayed in the measurement result display area 43 of the matrix scan display screen 40, in a predetermined file format. Figure 6 shows an example of the contents of the file output from the results output unit 21.

[0107] Here, the specified file format is, for example, HTML (HyperText Markup Language) or CSV (Comma Separated Values). The file output from the result output unit 21 may be stored in the data storage unit 30, or it may be stored in an external storage device or a computer-readable recording medium.

[0108] Below, an example of the error measurement method using the error measurement device 1 of this embodiment will be described with reference to the flowchart in Figure 7. Note that when error measurement is performed, it is assumed that the DUT 100 has transitioned to the signal pattern folding state. Explanations that overlap with the above-described explanation of the configuration of the error measurement device 1 will be omitted as appropriate.

[0109] First, the control unit 15 displays a matrix scan display screen 40 on the operation display unit 32 for setting the matrix scan function (step S1).

[0110] Next, the user inputs various settings necessary to execute the matrix scan function into the matrix scan display screen 40 via the operation display unit 32 (step S2).

[0111] In step S2, for example, the measurement time of the signal under test from DUT100 is input to spin box 44 labeled "BER Meas. Time[sec]", and the target error rate ER is input to spin boxes 52a and 52b labeled "ER". s The input is entered, and the target error count E is entered into spin box 53 labeled "EC".

[0112] In step S2, with the [Scan] tab 42c selected in the parameter setting display area 42 of the matrix scan display screen 40, the Full Swing value (24, 48, or 63) is selected for "FS (Full Swing)", the scan direction (e.g., Horizontal) is set for "Search Direction", the checkbox 45 for "Full Scan" is checked, or "Start from Selected Cell" or "Scan Scenario" is selected for "Scan Mode" to set the scan target.

[0113] Next, the reliability level calculation unit 20 calculates the data rate of the signal under measurement and the measurement time and target error rate ER, which were input to the matrix scan display screen 40 in step S2. S Based on the target number of errors E, the target reliability level CL S Calculate the reliability level (reliability level calculation step S3).

[0114] Next, the display control unit 17 displays the target reliability level CL calculated in the reliability level calculation step S3 in the "Target CL" text box 51 on the display screen of the operation display unit 32, for example, as shown in the matrix scan display screen 40 in Figures 2 to 4. S Display (Step S4).

[0115] Next, the data transmission unit 10 of the error measurement device 1, under the control of the control unit 15, sequentially generates test signals based on the parameters to be scanned and transmits the sequentially generated test signals to the DUT 100 (step S5). That is, the data transmission unit 10 sequentially generates emphasized test signals based on parameter values ​​consisting of a table of triangular matrix values ​​mapped from the coefficients of preset cursor values ​​defined in the PCIe Gen6 standard for the test pattern selected by the operation display unit 32, and transmits them to the DUT 100.

[0116] Under the control of the control unit 110, the DUT100 receives test signals sequentially transmitted from the data transmission unit 10 of the error measurement device 1 using the data reception unit 120, and transmits a response signal to the received test signal back to the error measurement device 1 as the signal to be measured via the data transmission unit 130.

[0117] The data receiving unit 12 of the error measurement device 1 receives the signal to be measured, which is transmitted sequentially by the data transmitting unit 130 of the DUT 100 (step S6).

[0118] Next, the error measurement unit 14 counts the number of errors in the signal under measurement over the measurement time entered on the matrix scan display screen 40 in step S2, and calculates the error rate of the signal under measurement (error measurement step S7).

[0119] Next, the reliability level calculation unit 20 calculates the data rate of the signal under measurement and the measurement time and target error rate ER entered into the matrix scan display screen 40 in step S2. S Based on the number of errors measured in the error measurement step S7, the reliability level CL is calculated (reliability level calculation step S8).

[0120] Next, the display control unit 17 displays the measurement results and the reliability level CL calculated in the reliability level calculation step S8 in the measurement result display area 43 (table display area 46, detail display area 47) on the display screen of the operation display unit 32, for example, as shown in the matrix scan display screen 40 in Figures 2 to 4 (step S9).

[0121] As described above, the error measurement device 1 according to this embodiment displays a target reliability level CL in accordance with the measurement conditions during the execution of the matrix scan function on the matrix scan display screen 40, which is used to set the measurement conditions during the execution of the matrix scan function. S This displays the target reliability level CL. S This eliminates the need to calculate the value.

[0122] Furthermore, the error measurement device 1 according to this embodiment displays the reliability level CL of the signal under measurement during the execution of the matrix scan function on the matrix scan display screen 40, which displays the measurement results during the execution of the matrix scan function. As a result, the error measurement device 1 according to this embodiment can automatically evaluate the reliability level CL of each of the many measurement results obtained by the matrix scan function and present it to the user.

[0123] Furthermore, the error measurement device 1 according to this embodiment has a target reliability level CL that matches the measurement conditions when the matrix scan function is executed. S The measurement results and reliability level CL during the execution of the matrix scan function are displayed on the matrix scan display screen 40. Thus, the error measurement device 1 according to this embodiment allows the user to set a target reliability level CL. S This facilitates the verification of measurement results during matrix scanning by comparing them with the reliability level CL.

[0124] Furthermore, the error measurement device 1 according to this embodiment displays the target error rate ER of the signal under measurement in the parameter setting display area 42 of the matrix scan display screen 40. s , target error count E, and target reliability level CL S Various measurement conditions, including those mentioned above, are output in a predetermined file format. This allows the error measurement device 1 according to this embodiment to output the target reliability level CL, which is consistent with the measurement conditions at the time of the matrix scan, even at a later date after the matrix scan function has been executed. S This can be confirmed.

[0125] Furthermore, the error measurement device 1 according to this embodiment outputs the calculated values ​​of PS2, PS1, DE, and Boost, the measured values ​​of EC and BER, and the reliability level CL value based on EC, which are displayed in the measurement result display area 43 of the matrix scan display screen 40, in a predetermined file format. This makes it easy for the error measurement device 1 according to this embodiment to verify the measurement results at the time of execution of the matrix scan function based on the reliability level CL, even at a later date after the execution of the matrix scan function.

[0126] Furthermore, although the error measurement device 1 according to this embodiment was described using the PCI Express 6 standard as an example, the present invention is not limited to this standard and can be applied to devices having equivalent matrix scanning capabilities. [Explanation of Symbols]

[0127] 1. Error measuring device 10 Data transmission unit 11 Emphasis Control Unit 12 Data receiving unit 14 Error Measurement Unit 15 Control Unit 16. Link Status Management Unit 17 Display Control Unit 18 Transmission speed conversion unit 20 Reliability Level Calculation Unit 21 Result Output Section 30 Data storage unit 32 Operation display section 40 Matrix scan display screen (display screen) 42 Parameter setting display area 42a, 42b, 42c tabs 43 Measurement result display area 44 Spin Box 45 checkboxes 46 Table display area 47 Detail display area 48a, 48b, 48c Input Boxes 49 buttons 51 Text Box 52a, 52b Spin Box 53 Spin Box 60 Matrix scan editing screen (display screen) 100 DUT 110 Control Unit 111 Link Status Management Unit 120 Data receiving unit 121 Equalizer 130 Data transmission unit

Claims

1. C in the Full Swing value as defined in the PCI Express standard －２ , C －１ , C ＋１ An error measuring device (1) performs a matrix scan function that measures the number of errors and the error rate of the measured signal by receiving a measured signal that is reflected back from the measured object (100) in conjunction with the transmission of the test signal, based on the parameter values ​​of the cells to be scanned, selected and set from a triangular matrix of combinations of coefficient values, during link training, The coefficient value of C is selectively displayed by tabs in a number corresponding to the Full Swing value, and each combination of the coefficient value of C of the selected tab and each coefficient value of C and each coefficient value of C is displayed in a matrix on the display screen as the cell. At the same time, C is used as the horizontal coordinate axis, C is used as the vertical coordinate axis, and C is used as the depth direction coordinate axis, and C, C, and C are three-dimensionally displayed in a bird's-eye view on the display screen. A display control unit (17); －２ The coefficient value of C can be selectively displayed by tabs in a number corresponding to the Full Swing value, and the coefficient value of C of the selected tab and each coefficient value of C and each coefficient value of C are displayed in a matrix on the display screen as the cell. At the same time, C is used as the horizontal coordinate axis, C is used as the vertical coordinate axis, and C is used as the depth direction coordinate axis, and C, C, and C are three-dimensionally displayed in a bird's-eye view on the display screen. A display control unit (17); －２ The coefficient value of C of the selected tab and each coefficient value of C and each coefficient value of C are displayed in a matrix on the display screen as the cell. At the same time, C is used as the horizontal coordinate axis, C is used as the vertical coordinate axis, and C is used as the depth direction coordinate axis, and C, C, and C are three-dimensionally displayed in a bird's-eye view on the display screen. A display control unit (17); ＋１ Each coefficient value of C and each coefficient value of C and each coefficient value of C are displayed in a matrix on the display screen as the cell. At the same time, C is used as the horizontal coordinate axis, C is used as the vertical coordinate axis, and C is used as the depth direction coordinate axis, and C, C, and C are three-dimensionally displayed in a bird's-eye view on the display screen. A display control unit (17); －１ Each combination of the coefficient value of C of the selected tab and each coefficient value of C and each coefficient value of C is displayed in a matrix on the display screen as the cell. At the same time, C is used as the horizontal coordinate axis, C is used as the vertical coordinate axis, and C is used as the depth direction coordinate axis, and C, C, and C are three-dimensionally displayed in a bird's-eye view on the display screen. A display control unit (17); ＋１ Using C as the horizontal coordinate axis, C as the vertical coordinate axis, and C as the depth direction coordinate axis, C, C, and C are three-dimensionally displayed in a bird's-eye view on the display screen. A display control unit (17); －１ Using C as the vertical coordinate axis, C as the depth direction coordinate axis, C, C, and C are three-dimensionally displayed in a bird's-eye view on the display screen. A display control unit (17); －２ Using C as the depth direction coordinate axis, C, C, and C are three-dimensionally displayed in a bird's-eye view on the display screen. A display control unit (17); －２ C, C, and C are three-dimensionally displayed in a bird's-eye view on the display screen. A display control unit (17); －１ C, C, and C are three-dimensionally displayed in a bird's-eye view on the display screen. A display control unit (17); ＋１ A display control unit (17) that three-dimensionally displays C, C, and C in a bird's-eye view on the display screen; An operation display unit (32) for selecting and setting a range that includes at least one of the cells to be scanned in the matrix display or the overview display, A control unit (15) that executes the matrix scan function using parameter values ​​within the range selected and set on the operation display unit, An error measurement unit (14) measures the number of errors and the error rate of the signal under measurement over a predetermined measurement period, The system includes a reliability level calculation unit (20) that calculates a reliability level relating to the allowable value of the error rate of the signal under measurement, The aforementioned display screen is A measurement time input unit (44) for inputting the measurement time of the signal to be measured, A target error rate input unit (52a, 52b) for inputting the allowable value of the error rate of the signal under measurement, A target error input unit (53) for inputting an acceptable value for the number of errors during the measurement time of the signal under measurement, It includes a reliability level display unit (51) that displays the aforementioned reliability level, The error measurement device is characterized in that the reliability level calculation unit calculates the reliability level based on the data rate of the signal to be measured, the measurement time, the allowable value of the error rate, and the allowable value of the number of errors, which are input to the display screen.

2. The reliability level calculation unit substitutes the product of the data rate and the measurement time into N in the following formula (2), and the allowable value of the error rate is calculated as ER in the following formula (2). Ｓ The error measuring device according to claim 1, characterized in that the reliability level is calculated by substituting the values ​​into the following formula (2) and substituting the allowable number of errors into E. [Math 1]

3. The error measuring device according to claim 1 or 2, further comprising a result output unit (21) that outputs the allowable value of the error rate, the allowable value of the number of errors, and the reliability level displayed on the display screen in a predetermined file format.

4. C in the Full Swing value as defined in the PCI Express standard －２ , C －１ , C ＋１ An error measurement method that performs a matrix scan function to measure the number of errors and the error rate of the measured signal, which involves sending a test signal to the object under test (100) during link training based on the parameter values ​​of the cells to be scanned, selected and set from a triangular matrix of combinations of coefficient values, and receiving the measured signal that is reflected back from the object under test in conjunction with the transmission of the test signal, According to the number of tabs corresponding to the Full Swing value, C －２ Step (S1) displays the coefficient value in a selectable format, The C of the selected tab －２ The coefficient value and the aforementioned C ＋１ Each coefficient value and the C －１ Step (S1) is to display each combination of each coefficient value as a cell in a matrix on the display screen, Said C ＋１ The horizontal coordinate axis, C －１ The vertical coordinate axis, and the C －２ Using the depth coordinate axis, the C －２ , said C －１ , said C ＋１ Step (S1) of displaying the above on the display screen in a three-dimensional overhead view, Step (S2) of selecting and setting a range that includes at least one of the cells to be scanned in the matrix display or the overview display, A reliability level calculation step (S3) for calculating the reliability level related to the allowable value of the error rate of the signal under measurement, The steps include: displaying the reliability level on the display screen (S4), The steps include (S5 to S7) executing the matrix scan function using the parameter values ​​within the selected range, The step of performing the matrix scan function includes an error measurement step (S7) of measuring the number of errors and the error rate of the signal under measurement over a predetermined measurement time, The aforementioned display screen is A measurement time input unit (44) for inputting the measurement time of the signal to be measured, A target error rate input unit (52a, 52b) for inputting the allowable value of the error rate of the signal under measurement, A target error input unit (53) for inputting an acceptable value for the number of errors during the measurement time of the signal under measurement, It includes a reliability level display unit (51) that displays the aforementioned reliability level, The error measurement method is characterized in that the reliability level calculation step calculates the reliability level based on the data rate of the signal to be measured, the measurement time, the allowable value of the error rate, and the allowable value of the number of errors, which are input to the display screen.

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