Link test method, computer equipment, storage medium and program product

Abstract

The invention discloses a link testing method, computer equipment, a storage medium and a program product, and relates to the technical field of link testing, and the method comprises the steps: obtaining a first amplitude value of a first received signal and a second amplitude value of a second received signal, the first received signal is obtained after a first source signal is transmitted through a target link, and the second received signal is obtained after a second source signal is transmitted through the target link; the second receiving signal is obtained after a second source signal is transmitted through the target link, and the first source signal and the second source signal are different in frequency; calculating the total link loss under the target frequency based on a loss difference value determined by the first amplitude value and the second amplitude value, the first frequency of the first source signal and the second frequency of the second source signal; and calculating the compensation loss according to the preset link total loss and the link total loss, so as to execute simulation compensation on the target link, obtain the target test signal waveform transmitted by the target link after the simulation compensation is executed, and further determine the link test result, thereby solving the technical problem of tedious link test in related technologies, and improving the link test efficiency. The technical effect of improving the link test efficiency is achieved.

Description

Technical Field

[0001] The present application relates to the field of link testing technology, and in particular to a link testing method, computer equipment, storage medium, and program product. Background Art

[0002] The current link testing method mainly uses a test fixture to lead out the test signal from the link transmitter and the signal from the link receiver, calculates the link loss during the transmission of the test signal from the link transmitter to the link receiver, and then calculates the compensation value based on the loss value to compensate the link. Then, a standard test environment is constructed to test the link. However, each time a link test is performed, a test fixture is required to measure the link loss and then calculate the compensation value, which is cumbersome. Summary of the Invention

[0003] The present application provides a link testing method, computer equipment, storage medium and program product to solve the complex technical problems of link testing in related technologies.

[0004] This application provides a link testing method, which is applied to a signal analysis device. The link testing method includes: Obtain a first amplitude value of a first received signal and a second amplitude value of a second received signal, wherein the first received signal is obtained after the first source signal is transmitted through the target link, and the second received signal is obtained after the second source signal is transmitted through the target link, and the first source signal and the second source signal have different frequencies; determine a loss difference based on the first amplitude value and the second amplitude value; calculate the total link loss at the target frequency based on the loss difference, the first frequency of the first source signal, and the second frequency of the second source signal; calculate the compensation loss based on the preset link total loss and the total link loss, and the compensation loss is used to perform simulation compensation on the target link; obtain a target test signal waveform transmitted through the target link after performing simulation compensation, and determine a link test result based on the target test signal waveform.

[0005] The present application also provides a computer device, comprising: a memory for storing a computer program; and a processor for implementing the steps of the link testing method in the following implementation manner when executing the computer program.

[0006] Obtain a first amplitude value of a first received signal and a second amplitude value of a second received signal, wherein the first received signal is obtained after the first source signal is transmitted through the target link, and the second received signal is obtained after the second source signal is transmitted through the target link, and the first source signal and the second source signal have different frequencies; determine a loss difference based on the first amplitude value and the second amplitude value; calculate the total link loss at the target frequency based on the loss difference, the first frequency of the first source signal, and the second frequency of the second source signal; calculate the compensation loss based on the preset link total loss and the total link loss, and the compensation loss is used to perform simulation compensation on the target link; obtain a target test signal waveform transmitted through the target link after performing simulation compensation, and determine a link test result based on the target test signal waveform.

[0007] The present application also provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the steps of the link testing method in the following embodiment are implemented.

[0008] Obtain a first amplitude value of a first received signal and a second amplitude value of a second received signal, wherein the first received signal is obtained after the first source signal is transmitted through the target link, and the second received signal is obtained after the second source signal is transmitted through the target link, and the first source signal and the second source signal have different frequencies; determine a loss difference based on the first amplitude value and the second amplitude value; calculate the total link loss at the target frequency based on the loss difference, the first frequency of the first source signal, and the second frequency of the second source signal; calculate the compensation loss based on the preset link total loss and the total link loss, and the compensation loss is used to perform simulation compensation on the target link; obtain a target test signal waveform transmitted through the target link after performing simulation compensation, and determine a link test result based on the target test signal waveform.

[0009] The present application also provides a computer program product, including a computer program, which implements the steps of the link testing method in the following embodiment when the computer program is executed by a processor.

[0010] Obtain a first amplitude value of a first received signal and a second amplitude value of a second received signal, wherein the first received signal is obtained after the first source signal is transmitted through the target link, and the second received signal is obtained after the second source signal is transmitted through the target link, and the first source signal and the second source signal have different frequencies; determine a loss difference based on the first amplitude value and the second amplitude value; calculate the total link loss at the target frequency based on the loss difference, the first frequency of the first source signal, and the second frequency of the second source signal; calculate the compensation loss based on the preset link total loss and the total link loss, and the compensation loss is used to perform simulation compensation on the target link; obtain a target test signal waveform transmitted through the target link after performing simulation compensation, and determine a link test result based on the target test signal waveform.

[0011] The link testing method provided by the present application obtains the first amplitude value of the first received signal and the second amplitude value of the second received signal, the first received signal is obtained after the first source signal is transmitted through the target link, and the second received signal is obtained after the second source signal is transmitted through the target link, and the first source signal and the second source signal have different frequencies; the loss difference is determined based on the first amplitude value and the second amplitude value; the total link loss at the target frequency is calculated based on the loss difference, the first frequency of the first source signal and the second frequency of the second source signal; the compensation loss is calculated according to the preset total link loss and the total link loss, and the compensation loss is used to perform simulation compensation on the target link; the target test signal waveform transmitted through the target link after the simulation compensation is performed is obtained, and the link test result is determined according to the target test signal waveform. In this way, by calculating the total link loss at the target frequency, the full-band scanning of the target link is avoided, saving the link detection time. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0013] Figure 1 It is a structural diagram of a link test system in related art 1; Figure 2 It is a structural diagram of the link test system in the related technology 2; Figure 3 A schematic diagram of the structure of a link testing system provided in one embodiment of the present application; Figure 4 A flowchart of a link testing method provided in one embodiment of the present application; Figure 5 A schematic diagram of signal waveforms provided in an embodiment of the present application; Figure 6 A flowchart of a link testing method provided in another embodiment of the present application; Figure 7 A schematic diagram of the structure of a link testing device provided in one embodiment of the present application; Figure 8 This is a diagram of the internal structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0014] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of this application.

[0015] It should be noted that, in the description of this application, the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. The terms "first," "second," etc., in this application are used to distinguish similar objects, and are not used to describe a particular order or sequence.

[0016] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0017] The PCI Express (PCIE) protocol is a high-speed serial computer expansion bus standard used to connect peripheral devices to computer systems. Compared to traditional parallel bus standards such as PCI and PCI-X, PCIE offers lower latency and higher data transfer rates. Each device connected to the motherboard is connected to it via an independent point-to-point connection, eliminating the competition for bandwidth between devices sharing the same bus. With its advantages such as high-speed data transmission, low latency, scalability, hot-swap support, versatility, high reliability, and strong compatibility, the PCIE protocol is widely used in graphics processing, AI computing, storage controllers, network adapters, accelerator cards and coprocessors, sound cards, video capture cards, and other expansion cards, playing an increasingly important role in modern computer systems.

[0018] PCIE interface conformance testing is a crucial step in verifying the performance and compatibility of PCIE devices, ensuring compliance with PCIE standards and stable data transmission. PCIE TX testing focuses on evaluating the performance and consistency of data transmitted by the device, including key metrics such as transmission link status, data transfer rate, and signal quality. PCIE TX testing primarily verifies the performance of the signal transmitter of PCIE devices (such as CPUs, GPUs, and network cards) to ensure that the signal quality they transmit meets standard specifications and can be correctly interpreted by the receiving end.

[0019] Performing PCIE TX testing with professional testing tools can ensure that PCIE devices meet performance requirements in actual applications and provide guarantees for efficient and stable data transmission.

[0020] See also Figure 1 In related technology 1, the test signal originates from the CPU, passes through the CPU package, the motherboard PCB traces, the CEM connector, and the expansion card before reaching the integrated circuit on the expansion card. The link loss at this point mainly consists of two components: motherboard loss and expansion card loss.

[0021] Motherboard: The test signal originates from the CPU, passes through the CPU package, and then through the motherboard PCB traces to the PCIE CEM connector (slot) on the motherboard. Motherboard losses primarily come from the CPU package and the motherboard PCB traces.

[0022] Expansion card: The test signal enters the expansion card through the PCIE CEM connector, travels along the card's PCB traces, and reaches the device package on the expansion card. Losses in the expansion card primarily come from losses in the PCIE CEM connector slot and gold finger itself, losses in the card's PCB traces, and losses in the integrated circuit package on the expansion card.

[0023] According to the PCI-SIG PHY Test Specification, in PCI-E Tx testing, the full link loss, including the CPU and AIC (expansion card, a term for various cards that can be added to the motherboard to expand system functionality), should be 36dB @ 16GHz. This 36dB limit is an extremely stringent upper limit for the total signal loss of the transmitter test channel, established to ensure stable system operation at the ultra-high speed of 64GT / s. @ 16GHz means the loss value is defined at a frequency of 16GHz. This means that when performing link testing, the link loss must be 36dB.

[0024] See also Figure 2 In the second related technology, before performing the PCIE TX test, it is necessary to measure and calibrate the full link loss including the test fixture, cables and PCB traces, and then fill in the link loss by embedding S parameters in the oscilloscope to build the target of a total link loss of 36dB required by the specification, so as to simulate a standard test environment that meets the full link loss of 36dB@16GHz on the oscilloscope, and thus fairly and accurately evaluate the quality of the original signal emitted by the CPU.

[0025] Currently, link loss testing is typically performed using a VNA (vector network analyzer). Signals from the CPU and device (CEM connector slot, the physical interface for expansion cards on the motherboard) are extracted using a test fixture and connected to the VNA for loss testing. The loss from the CPU package to the test fixture is measured and recorded as A.

[0026] Vector network analyzer is a professional instrument for measuring S parameters. Use the test fixture to draw out the signal points of the CPU slot and expansion card slot on the motherboard, such as Figure 2 The CPU slot is connected to the VNA through PORT1, and the CEM connector slot is connected to the VAN through the test fixture and PORT2.

[0027] Before performing PCIE TX testing, link loss compensation must be performed to meet association specifications. The compensation value is denoted as B. Compensation B = Preset Total Link Loss - Loss A - CPU Package Loss - Loss of the Test Signal Path to the Oscilloscope (mainboard PCB traces, test fixture CLB, and cables). CPU package loss is provided by the CPU manufacturer, while cable loss can be measured (approximately 1.5 dB).

[0028] The compensation value B is embedded in the oscilloscope in the form of S parameters. After the embedded compensation, the waveform displayed on the oscilloscope screen is the standard waveform of the model sent by the CPU after the total link loss is 36dB, so as to build a test environment with a total loss of 36dB on the oscilloscope end.

[0029] However, VNA link loss measurement in related technologies is cumbersome, and the results are significantly affected by the test environment and test techniques, making it prone to inaccurate results. Furthermore, to ensure test results comply with protocol specifications, link loss must be remeasured and compensated whenever the test topology is changed, which is cumbersome and labor-intensive. Loss estimates for components such as the CPU package may deviate from actual results, leading to inaccurate test results. Furthermore, link loss measurement and PCIE TX testing are performed separately, making it impossible to reflect in real time the impact of environmental factors such as temperature and humidity fluctuations and electromagnetic interference on current link loss and test results.

[0030] See also Figure 3The link test system of this application mainly includes a transmitter (CPU) and a receiver (signal analysis equipment, such as the oscilloscope shown in the figure). The transmitter and receiver transmit signals through a target link, which is specifically the link from the motherboard, test fixture, and cable to the oscilloscope shown in the figure. The receiver can also be a vector signal analyzer (VSA), an integrated analysis module of a bit error rate tester (BERT), a dedicated protocol analyzer, or even an industrial computer with a built-in high-speed acquisition card, etc., which is an electronic test and measurement device capable of performing signal acquisition, waveform analysis, and embedded S-parameter or filter functions.

[0031] In response to the above technical issues, such as Figure 4 As shown, an embodiment of the present application provides a link testing method, which is applied to a signal analysis device. The method specifically includes the following steps: Step 101: Obtain a first amplitude value of a first received signal and a second amplitude value of a second received signal, where the first received signal is obtained by transmitting a first source signal through a target link, and the second received signal is obtained by transmitting a second source signal through the target link, and the first source signal and the second source signal have different frequencies.

[0032] First, the transmitting end sends the first source signal and the second source signal to the target link respectively, and transmits the first source signal and the second source signal to the receiving end through the target link. Since the first source signal and the second source signal will be lost when transmitted in the link, the receiving end receives the first received signal obtained after the first source signal is transmitted through the target link, and the second received signal obtained after the second source signal is transmitted through the target link. Here, the first source signal can be a high-frequency signal and the second source signal can be a low-frequency signal. Correspondingly, the first received signal is a high-frequency signal and the second received signal is a low-frequency signal.

[0033] Because high-frequency and low-frequency signals are affected differently by factors such as skin effect, dielectric loss, stray capacitance and inductance, as well as signal radiation and conduction during link transmission, signal transmission media such as PCBs and cables attenuate high-frequency and low-frequency signals to varying degrees. Generally, higher signal frequencies result in greater signal loss. The skin effect refers to the phenomenon in which, when high-frequency signals are transmitted through a conductor, current is concentrated more on the conductor's surface, reducing the effective transmission area and increasing resistance, leading to signal attenuation. This is one of the causes of high-frequency signal loss. Generally speaking, the higher the frequency, the more pronounced the skin effect and the greater the signal loss. Dielectric loss refers to the phenomenon in which signals are lost through transmission media such as PCBs and cables, as part of the electromagnetic energy is converted into heat due to the polarization and absorption properties of the dielectric material. The degree of attenuation varies with signal frequency. Stray capacitance refers to unwanted parasitic capacitance in a circuit, formed by electric field coupling between conductors. It interferes with signal transmission, affecting signal integrity and leading to signal loss or distortion.

[0034] like Figure 5 , for sine wave signals of different frequencies with the same amplitude, after passing through the same link, the amplitude of the low frequency is attenuated less (the waveform above), while the amplitude of the high frequency is attenuated more (the waveform below).

[0035] In this application, the first source signal and the second source signal with the same amplitude but different frequency are input into the same link through the transmitting end, and the relationship between the link loss and the frequency is obtained (such as the relationship between the attenuation constant and the frequency). The total loss of the link can be inferred by the amplitude difference of the signals with different frequencies.

[0036] In one embodiment, before inputting the first source signal and the second source signal into the target link, a first initial amplitude value of the first source signal and a second initial amplitude value of the second source signal may be obtained to determine whether the first initial amplitude value and the second initial amplitude value are consistent. If the first initial amplitude value and the second initial amplitude value are consistent, the first source signal and the second source signal are directly input into the target link. If the first initial amplitude value and the second initial amplitude value are inconsistent, the initial amplitude value of the first source signal or the initial amplitude value of the second source signal is calibrated based on the difference between the first initial amplitude value and the second initial amplitude value so that the initial amplitude values ​​of the first source signal and the second source signal after calibration are the same, and the first source signal and the second source signal with the same initial amplitude value after calibration are input into the target link.

[0037] Step 102: Determine a loss difference based on the first amplitude value and the second amplitude value.

[0038] Specifically, the first amplitude value and the second amplitude value are converted into a first loss value and a second loss value respectively; the difference between the first loss value and the second loss value is calculated, and the difference is used as the loss difference; The loss difference is expressed as: ; △A represents the loss difference, A1 represents the first amplitude value, and A2 represents the second amplitude value.

[0039] The first and second amplitude values ​​here can be measured voltage amplitudes. Assuming the initial amplitude values ​​of the first and second source signals are A0, when transmitted through the link, the total loss of the link will attenuate the signal. Generally, the greater the total loss, the smaller the amplitude value measured by the receiving end. Assuming the measured first amplitude value of the first received signal F1 is A1, and the second amplitude value of the second received signal F2 is A2, the total loss of the first received signal is: SL(F1) = 20*log10(A0 / A1); the total loss of the second received signal is: SL(F2) = 20*log10(A0 / A2). Arranging these two formulas yields △A. Here, the loss difference is calculated based on the actual measured voltage amplitude to facilitate the subsequent calculation of the total link loss.

[0040] Step 103: Calculate the total link loss at the target frequency based on the loss difference, the first frequency of the first source signal, and the second frequency of the second source signal.

[0041] In one embodiment, a loss-frequency relationship function is determined, and a loss difference is determined based on the loss-frequency relationship function; a proportional parameter is determined based on the loss difference, the first frequency, and the second frequency, the proportional parameter being used to characterize a target link loss characteristic; and a total link loss at the target frequency is calculated based on the proportional parameter, the target frequency, and a total link loss formula. The loss difference is expressed as: ; ΔA represents the loss difference, a(f1) represents the target link loss coefficient per unit length at the first frequency, a(f2) represents the target link loss coefficient per unit length at the second frequency, L represents the target link length, and k represents the target link dielectric loss coefficient.

[0042] This application assumes that the link loss model is a(f) (unit: dB / inch or dB / m), and the signal transmission distance is L, then the total loss = a(f)·L. Establish the relationship function between loss and frequency. For cables, the attenuation constant is usually is proportional to , where f is the signal frequency and k is a constant. (Different media have different attenuation models, but they can all be defined as a function of frequency f.) If the relative loss difference between a high-frequency signal (frequency f1) and a low-frequency signal (frequency f2) is known to be ΔA (in dB), ΔA here represents the relationship between the theoretical loss difference and the proportionality parameter, which is primarily used to derive the proportionality parameter.

[0043] Specifically, the scale parameter is expressed as: ; kL represents a proportional parameter, k represents a target link dielectric loss coefficient, which is used to characterize the target link dielectric loss characteristics, L represents a target link length, which is used to characterize the target link length loss characteristics, f1 represents a first frequency, and f2 represents a second frequency.

[0044] It's understandable that k here reflects the attenuation caused by the inherent properties of the transmission line dielectric material and is unaffected by signal frequency. kL represents the inherent, frequency-invariant physical properties of the target link. Therefore, when subsequently testing the target link using different test signals, the corresponding ratio parameters and amplitude values ​​can be used to quickly calculate the loss value.

[0045] After obtaining the proportional parameters, the total link loss formula is derived based on the total loss = a(f)·L: ; Wherein, SL(f) represents the total link loss at the target frequency, kL represents the proportional parameter, ΔA represents the loss difference, f represents the target frequency, f1 represents the first frequency, and f2 represents the second frequency.

[0046] This application uses the different attenuation levels of high-frequency and low-frequency signals along a signal link (PCB traces or cables) to calculate link loss. The CPU (or other transmitting device) is controlled to transmit high-frequency and low-frequency signals of the same amplitude but different frequencies. An oscilloscope measures the amplitudes of the high-frequency and low-frequency signals after link attenuation. This calculation yields the overall link loss. By taking advantage of the different attenuation levels of high- and low-frequency signals along the signal transmission link, link loss is calculated by transmitting high- and low-frequency signals and measuring their amplitude difference. This overcomes the equipment limitations of traditional loss measurement, reduces testing costs, and simplifies the measurement process.

[0047] In another embodiment, calculating the target link total loss at the target frequency based on the loss difference, the first frequency of the first source signal, and the second frequency of the second source signal further includes: Determine the relationship function between temperature loss, dielectric loss and frequency, and determine the target loss difference based on the temperature loss, dielectric loss and the relationship function; determine the current target link ambient temperature loss coefficient corresponding to the current target link ambient temperature, and determine the target proportional parameter based on the current target link ambient temperature loss coefficient, the target loss difference, the first frequency and the second frequency. The target proportional parameter is used to characterize the target link loss characteristics; based on the target proportional parameter, the target frequency and the target link total loss formula, calculate the target link total loss at the target frequency.

[0048] Among them, the target loss difference is expressed as: ; △A1 represents the target loss difference, a(f1) represents the target link loss coefficient per unit length at the first frequency, a(f2) represents the target link loss coefficient per unit length at the second frequency, L represents the target link length, k represents the target link dielectric loss coefficient, and t represents the current target link ambient temperature loss coefficient.

[0049] The total loss formula of the target link is expressed as: ; Wherein, SL(f,T) represents the target link total loss at the target frequency, (k+t)L represents the scaling parameter, ΔA1 represents the target loss difference, f represents the target frequency, f1 represents the first frequency, and f2 represents the second frequency.

[0050] Determining the target link ambient temperature loss coefficient corresponding to the target link ambient temperature includes: Obtain the current target link ambient temperature, the reference target link ambient temperature, the current target link ambient temperature loss coefficient, the reference target link ambient temperature loss coefficient, the target link temperature coefficient, and the ambient temperature loss coefficient calculation formula; Input the current target link ambient temperature, the reference target link ambient temperature, the current target link ambient temperature loss coefficient, the reference target link ambient temperature loss coefficient, and the target link temperature coefficient into the ambient temperature loss coefficient calculation formula to obtain the current target link ambient temperature loss coefficient; Among them, the calculation formula of the ambient temperature loss coefficient is expressed as: t=t j [1+λ(TT j )]; t represents the current target link ambient temperature loss coefficient corresponding to the current target link ambient temperature T, t j Indicates the reference target link ambient temperature T j The corresponding reference target link ambient temperature loss coefficient, λ represents the target link temperature coefficient, which is used to characterize the sensitivity of the target link medium's loss coefficient to temperature changes.

[0051] In a feasible implementation, the same link can be measured at different temperature points (T) in a controlled environment (such as a temperature box) to obtain the total loss characteristics of the link at that temperature. The reference temperature can be set: usually T j =25°C. Measure multiple temperature points: For example, measure at four temperatures T = [25°C, 35°C, 55°C, 85°C]. Calculate kL(T) at each temperature: At each temperature T, measure the difference in loss ΔA between the high-frequency signal and the low-frequency signal at that temperature. i The proportionality factor at this temperature is calculated using the formula: kL(T) = ΔA i / (√f2 - √f1); Thus, the proportional factors corresponding to multiple temperature points are obtained. These proportional factors are then linearly regressed to form a straight line, and the slope of the fitted line is used as the target link temperature coefficient. By introducing the temperature coefficient λ, the link loss model is temperature-aware and adaptive, eliminating measurement errors introduced by ambient temperature changes.

[0052] In practical applications, the target link is a complex link composed of multiple transmission media. The link testing method further includes: determining the target transmission medium type corresponding to the multiple transmission media corresponding to the target link; determining the target transmission medium loss calculation formula based on the target transmission medium type; and calculating the total loss of the complex link based on the target transmission medium loss calculation formula.

[0053] Specifically, the target transmission medium type includes a first transmission medium, a second transmission medium, and a third transmission medium. Determining a target transmission medium loss calculation formula based on the target transmission medium type; calculating the total loss of the complex link based on the target transmission medium loss calculation formula includes: In response to the target transmission medium being the first transmission medium, the first transmission medium is a transmission line, such as an FR4 trace, a cable, or the like. A first transmission medium loss calculation formula corresponding to the first transmission medium is expressed as: ; ; Wherein, SL1(f,T) represents the total loss of the first transmission medium at the target frequency, (k1+t1)L1 represents the proportional parameter of the first transmission medium, which characterizes the loss characteristics of the first transmission medium, f represents the target frequency, t1 represents the current first transmission medium ambient temperature loss coefficient corresponding to the current first transmission medium ambient temperature T1, t j1 Indicates the reference first transmission medium ambient temperature T j1 The corresponding reference first transmission medium ambient temperature loss coefficient, λ1 represents the first transmission medium temperature coefficient, which is used to characterize the sensitivity of the first transmission medium's loss coefficient to temperature changes; In response to the target transmission medium being the second transmission medium, the second transmission medium being a connector, such as a certain type of connector or via, a second transmission medium loss calculation formula corresponding to the second transmission medium is expressed as: SL2(f,T)=(C+t2) f d ; t2=t j2 [1+λ2(T2-T j2 )]; Wherein, SL2(f,T) represents the total loss of the second transmission medium at the target frequency, C represents the loss coefficient of the second transmission medium, f represents the target frequency, d represents the correlation index between the second transmission medium and the frequency, t2 represents the current second transmission medium ambient temperature loss coefficient corresponding to the current second transmission medium ambient temperature T2, t j2 Indicates the reference second transmission medium ambient temperature T j2 The corresponding reference second transmission medium ambient temperature loss coefficient, λ2 represents the second transmission medium temperature coefficient, which is used to characterize the sensitivity of the second transmission medium's loss coefficient to temperature changes; In response to the target transmission medium being the third transmission medium, the third transmission medium being a device package, such as a CPU package, a transmission medium loss calculation formula corresponding to the third transmission medium is expressed as: SL3(f,T)=P·f dp ; Wherein, SL3(f,T) represents the total loss of the third transmission medium at the target frequency, P represents the loss coefficient of the third transmission medium, f represents the target frequency, and dp represents the correlation index between the third transmission medium and the frequency.

[0054] In this application, the loss coefficients of different transmission media can be stored in the database in advance for easy subsequent retrieval. The topology information of the target link is obtained, and according to the transmission medium composition of the target link reflected by the target link topology information, the corresponding transmission medium loss formula and the loss coefficient of the transmission medium are called to perform loss calculation, which can refine the loss calculation. At the same time, when encountering more complex links in the future, it is only necessary to split the more complex links into units of transmission media, call the corresponding transmission medium loss formula and the loss coefficient of the transmission medium to perform loss calculation, and integrate the loss calculation results according to the number of different transmission media to obtain the total link loss of the more complex link. It is not limited to a single medium link, and any complex hybrid link can be analyzed to simplify the total loss calculation of complex links.

[0055] Step 104: Calculate compensation loss according to the preset total link loss and the total link loss, and the compensation loss is used to perform simulation compensation on the target link.

[0056] Specifically, the preset total link loss is obtained. The preset total link loss here is used to characterize the required link loss for building a link test environment. The total link loss after subsequent compensation of the link needs to be consistent with the preset total link loss. Its value can be customized according to actual needs. This application does not limit the specific value of the preset total link loss, as long as it meets the requirements of the test environment for link testing.

[0057] Using the preset total link loss as the minuend and the total link loss as the subtrahend, a subtraction operation is performed. The difference obtained is the compensation loss value. This compensation loss value can be embedded into the target link using an oscilloscope in the form of S-parameters. S-parameters (Scattering Parameters) are a set of standard parameters used to describe how signals are reflected and transmitted in high-frequency networks. They establish the relationship between the incident wave, reflected wave, and transmitted wave between the input and output ports. Specifically, a special, idealized S-parameter model file can be generated based on the compensation loss value. This file has an S-parameter amplitude of 10^{-L2 / 20} and a phase of 0 (or linear phase) across the entire defined frequency range.

[0058] Load the generated S-parameter file into the "Channel Setting" or "De-embedding / Embedding" function module of the oscilloscope to realize simulation compensation of the target link.

[0059] Step 105: Obtain a target test signal waveform transmitted via the target link after simulation compensation is performed, and determine a link test result based on the target test signal waveform.

[0060] Specifically, after simulation compensation is performed on the target link, the transmitter will send a target test signal, which will be transmitted to the signal molecule device via the target link. At this time, the signal analysis device is already in the simulation compensation state, and can be triggered to execute the waveform acquisition function to obtain the target test signal waveform transmitted through the target link after simulation compensation is performed; what the signal analysis device acquires here is the final waveform of the test data signal after physical attenuation of the target link and simulation compensation inside the device.

[0061] Perform a waveform analysis operation on the target test signal waveform to obtain an analysis result reflecting the target link signal transmission quality, the waveform analysis operation including at least one of eye diagram analysis, jitter analysis, and amplitude analysis; determine the link test result based on the analysis result.

[0062] Based on the waveform data captured by the target test waveform, all possible unit intervals (UIs) can be superimposed to generate an eye diagram and measure the eye height and eye width. Eye height is the vertical opening of the eye diagram, and eye width is the horizontal opening. The eye diagram is then determined to see if it violates the PCIE protocol specification. If not, the eye diagram analysis result is a pass; otherwise, it fails. The timing error of signal edges can be decomposed into total jitter (the total time difference between the signal edge and its ideal position), deterministic jitter (predictable jitter caused by physical mechanisms such as ISI and crosstalk), and random jitter (unbounded jitter caused by noise and conforming to a Gaussian distribution). The overall jitter, deterministic jitter, and random jitter of the target test waveform are then determined to see if they violate the PCIE protocol specification. If not, the jitter analysis result is a pass; otherwise, it fails. Amplitude analysis can be performed by measuring signal voltage level parameters, such as peak voltage, average voltage, high level, and low level values, to determine whether the voltage level parameters of the target test waveform violate the PCIE protocol specifications. If not, the amplitude analysis result is a pass; otherwise, the amplitude analysis result is a fail. If the analysis operation results in a success, it indicates that the target link signal transmission quality meets the requirements, and the link test result is determined to be a pass. If any analysis operation results in a fail, it indicates that the target link signal transmission quality does not meet the requirements, and the link test result is determined to be a fail.

[0063] See also Figure 6 In a specific embodiment, the link testing method provided by this application can be shown as follows: Here, the signal sending module is the sending end, and the signal receiving and measuring module and the signal calculation and compensation module are the receiving end.

[0064] S1. Signal transmission module: This module controls the transmitting chip (CPU, etc.) to send high-frequency and low-frequency signals with the same initial amplitude to the target link. The high-frequency signal frequency f1 and the low-frequency signal frequency f2 satisfy the link loss and frequency correlation characteristics, and the difference in signal frequency between the two is set within a reasonable range to ensure that the amplitude difference at the receiving end can accurately reflect the link loss situation.

[0065] S2. Signal capture and measurement: At the receiving end, the first amplitude value A1 of the high-frequency signal and the second amplitude value A2 of the low-frequency signal are captured and measured respectively.

[0066] S3. Calculate the relative loss difference: Use the amplitude value to convert to dB loss difference and calculate the loss difference ΔA between the high and low frequency signals in the target link.

[0067] S4. Calculate the total link loss at the frequency to be tested: Based on the link type (such as the transmission medium and interface characteristics of the PCIE link), call a pre-established loss-frequency model (for cable links, a model related to the square root of frequency can be used). Substitute ΔA into the model to calculate the total link loss L1 at the frequency of the PCIE signal to be tested, and determine the degree of attenuation of the target signal by the link.

[0068] S5. Compensation value calculation: Compensation value L2 is calculated according to the formula L2 = 36 - |L1| (the compensation loss L2 is calculated based on the preset total link loss 36 and the total link loss L1). This compensation value is used to compensate for the total link loss required by the protocol and ensure the accuracy and consistency of signal quality analysis.

[0069] S6. Compensation value loading: The compensation value L2 is embedded into the target link in the form of S parameters through an oscilloscope.

[0070] S7. Post-compensation signal analysis: Measure and analyze the compensated PCIE TX signal at the receiving end, including parameters such as signal eye diagram, jitter, and amplitude, to evaluate the link signal transmission quality.

[0071] S8. can connect the oscilloscope and the device under test through Python API, realizing the automation of the entire process from signal transmission, loss calculation to compensation loading.

[0072] This application leverages the different attenuation levels of high- and low-frequency signals within a signal transmission link to calculate link loss by transmitting high- and low-frequency signals and measuring their amplitude difference. This overcomes the equipment limitations of traditional loss measurement, reduces testing costs, and simplifies the measurement process. Diverse loss-frequency relationship functions are established for different link types (cables, PCBs, etc.), enabling universal measurement across different media. This method can be applied to real-time link loss testing and calibration compensation in test scenarios such as PCIE TX, improving test efficiency and accuracy.

[0073] The embodiment of the present application provides a link test device, which is applied to a signal analysis device. The link test device is specifically as follows: Figure 7 As shown, the link testing device includes: an acquisition module 20 , a calculation module 21 and a determination module 22 .

[0074] The acquisition module 20 is used to obtain a first amplitude value of a first received signal and a second amplitude value of a second received signal, where the first received signal is obtained by transmitting the first source signal through a target link, and the second received signal is obtained by transmitting the second source signal through a target link, and the first source signal and the second source signal have different frequencies.

[0075] The calculation module 21 is used to determine the loss difference based on the first amplitude value and the second amplitude value; calculate the total link loss at the target frequency based on the loss difference, the first frequency of the first source signal and the second frequency of the second source signal; calculate the compensation loss according to the preset total link loss and the total link loss, and the compensation loss is used to perform simulation compensation on the target link.

[0076] The determination module is used to obtain the target test signal waveform transmitted through the target link after performing simulation compensation, and determine the link test result according to the target test signal waveform.

[0077] like Figure 8 As shown, an embodiment of the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute the steps in any one of the above-mentioned link testing method embodiments.

[0078] An embodiment of the present application further provides a computer-readable storage medium, in which a computer program is stored. The computer program is configured to execute the steps of any one of the above-mentioned link testing method embodiments when running.

[0079] In an exemplary embodiment, the computer-readable storage medium may include, but is not limited to, various media that can store computer programs, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk, or an optical disk.

[0080] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be judged to be beyond the scope of this application.

[0081] The above is a detailed introduction to a link testing method provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only intended to help understand the method and core ideas of the present application. It should be noted that, for those skilled in the art, without departing from the principles of the present application, several improvements and modifications may be made to the present application, and such improvements and modifications also fall within the scope of protection of the present application.

Claims

1. A link testing method, characterized in that: Applied to signal analysis equipment, the link testing method includes: Obtaining a first amplitude value of a first received signal and a second amplitude value of a second received signal, where the first received signal is obtained by transmitting a first source signal through a target link, and the second received signal is obtained by transmitting a second source signal through the target link, and the first source signal and the second source signal have different frequencies; determining a loss difference based on the first amplitude value and the second amplitude value; Calculate the total link loss at a target frequency based on the loss difference, the first frequency of the first source signal, and the second frequency of the second source signal; Calculating compensation loss according to the preset total link loss and the total link loss, wherein the compensation loss is used to perform simulation compensation on the target link; A target test signal waveform transmitted through a target link after simulation compensation is performed is obtained, and a link test result is determined according to the target test signal waveform.

2. The link testing method according to claim 1, wherein: The initial amplitude values ​​of the first source signal and the second source signal before entering the target link are the same; or based on the difference between the initial amplitude values ​​of the first source signal and the second source signal, the initial amplitude value of the first source signal and the initial amplitude value of the second source signal are calibrated so that the initial amplitude values ​​of the first source signal and the second source signal after calibration are the same.

3. The link testing method according to claim 1, wherein: Determining the loss difference based on the first amplitude value and the second amplitude value includes: Convert the first amplitude value and the second amplitude value into a first loss value and a second loss value respectively; Calculating a difference between the first loss value and the second loss value, and using the difference as a loss difference; The loss difference is expressed as: ； Wherein, ΔA represents the loss difference, A1 represents the first amplitude value, and A2 represents the second amplitude value.

4. The link testing method according to claim 1, wherein: Calculating the total link loss at the target frequency based on the loss difference, the first frequency of the first source signal, and the second frequency of the second source signal includes: Determine a loss-frequency relationship function, and determine a loss difference based on the loss-frequency relationship function; determining a proportional parameter based on the loss difference, the first frequency, and the second frequency, wherein the proportional parameter is used to characterize a target link loss characteristic; Calculate the total link loss at the target frequency based on the ratio parameter, target frequency, and the total link loss formula; The loss difference is expressed as: ； ΔA represents the loss difference, a(f1) represents the target link loss coefficient per unit length at the first frequency, a(f2) represents the target link loss coefficient per unit length at the second frequency, L represents the target link length, and k represents the target link dielectric loss coefficient.

5. The link testing method according to claim 4, wherein: The scale parameter is expressed as: ； kL represents a proportional parameter, k represents a target link dielectric loss coefficient, which is used to characterize the target link dielectric loss characteristics, L represents a target link length, which is used to characterize the target link length loss characteristics, f1 represents a first frequency, and f2 represents a second frequency.

6. The link testing method according to claim 4, wherein: The total link loss formula is expressed as: ； Wherein, SL(f) represents the total link loss at the target frequency, a(f) represents the loss coefficient per unit length of the target link at the target frequency, L represents the target link length, kL represents the scaling parameter, ΔA represents the loss difference, f represents the target frequency, f1 represents the first frequency, and f2 represents the second frequency.

7. The link testing method according to claim 1, wherein: Calculating the target link total loss at the target frequency based on the loss difference, the first frequency of the first source signal, and the second frequency of the second source signal further includes: Determine a relationship function between temperature loss, dielectric loss and frequency, and determine a target loss difference based on the temperature loss, dielectric loss and the relationship function; determining a current target link ambient temperature loss coefficient corresponding to a current target link ambient temperature, and determining a target proportional parameter based on the current target link ambient temperature loss coefficient, the target loss difference, the first frequency, and the second frequency, wherein the target proportional parameter is used to characterize a target link loss characteristic; Calculate the target link total loss at the target frequency based on the target ratio parameter, the target frequency, and the target link total loss formula; The target loss difference is expressed as: ； △A1 represents the target loss difference, a(f1) represents the target link loss coefficient per unit length at the first frequency, a(f2) represents the target link loss coefficient per unit length at the second frequency, L represents the target link length, k represents the target link dielectric loss coefficient, t represents the current target link ambient temperature loss coefficient, f1 represents the first frequency, and f2 represents the second frequency.

8. The link testing method according to claim 7, wherein: The target link total loss formula is expressed as: ； Wherein, SL(f,T) represents the target link total loss at the target frequency, (k+t)L represents the scaling parameter, ΔA1 represents the target loss difference, f represents the target frequency, f1 represents the first frequency, and f2 represents the second frequency.

9. The link testing method according to claim 7, wherein: Determining the target link ambient temperature loss coefficient corresponding to the target link ambient temperature includes: Obtain the current target link ambient temperature, the reference target link ambient temperature, the current target link ambient temperature loss coefficient, the reference target link ambient temperature loss coefficient, the target link temperature coefficient, and the ambient temperature loss coefficient calculation formula; Input the current target link ambient temperature, the reference target link ambient temperature, the current target link ambient temperature loss coefficient, the reference target link ambient temperature loss coefficient, and the target link temperature coefficient into the ambient temperature loss coefficient calculation formula to obtain the current target link ambient temperature loss coefficient; Among them, the calculation formula of the ambient temperature loss coefficient is expressed as: t=t j [1+λ(T-T j )]; t represents the current target link ambient temperature loss coefficient corresponding to the current target link ambient temperature T, t j Indicates the reference target link ambient temperature T j The corresponding reference target link ambient temperature loss coefficient, λ represents the target link temperature coefficient, which is used to characterize the sensitivity of the target link medium's loss coefficient to temperature changes.

10. The link testing method according to claim 1, wherein: The target link is a complex link composed of multiple transmission media, and the link testing method further includes: determining a target transmission medium type corresponding to multiple transmission media corresponding to the target link; Determine a target transmission medium loss calculation formula based on the target transmission medium type; The total loss of the complex link is calculated based on the target transmission medium loss calculation formula.

11. The link testing method according to claim 10, wherein: The target transmission medium type includes a first transmission medium, a second transmission medium, and a third transmission medium, and the target transmission medium loss calculation formula is determined based on the target transmission medium type; Calculating the total loss of a complex link based on the target transmission medium loss calculation formula includes: In response to the target transmission medium being a first transmission medium, the first transmission medium being a transmission line, a first transmission medium loss calculation formula corresponding to the first transmission medium is expressed as: ； ； Wherein, SL1(f,T) represents the total loss of the first transmission medium at the target frequency, (k1+t1)L1 represents the proportional parameter of the first transmission medium, which characterizes the loss characteristics of the first transmission medium, f represents the target frequency, t1 represents the current first transmission medium ambient temperature loss coefficient corresponding to the current first transmission medium ambient temperature T1, t j1 Indicates the reference first transmission medium ambient temperature T j1 The corresponding reference first transmission medium ambient temperature loss coefficient, λ1 represents the first transmission medium temperature coefficient, which is used to characterize the sensitivity of the first transmission medium's loss coefficient to temperature changes; In response to the target transmission medium being the second transmission medium, and the second transmission medium being a connector, a second transmission medium loss calculation formula corresponding to the second transmission medium is expressed as: SL2(f,T)=(C+t2)f d ; t2=t j2 [1+λ2(T2-T j2 )]; Where SL2(f,T) represents the total loss of the second transmission medium at the target frequency, C represents the loss coefficient of the second transmission medium, f represents the target frequency, d represents the correlation index between the second transmission medium and the frequency, t2 represents the current second transmission medium ambient temperature loss coefficient corresponding to the current second transmission medium ambient temperature T2, t j2 Indicates the reference second transmission medium ambient temperature T j2 The corresponding reference second transmission medium ambient temperature loss coefficient, λ2 represents the second transmission medium temperature coefficient, which is used to characterize the sensitivity of the second transmission medium's loss coefficient to temperature changes; In response to the target transmission medium being the third transmission medium, the third transmission medium being a device package, a transmission medium loss calculation formula corresponding to the third transmission medium is expressed as: SL3(f,T)=P·f dp ; Wherein, SL3(f,T) represents the total loss of the third transmission medium at the target frequency, P represents the loss coefficient of the third transmission medium, f represents the target frequency, and dp represents the correlation index between the third transmission medium and the frequency.

12. The link testing method according to claim 1, wherein: The step of obtaining a target test signal waveform transmitted through a target link after simulation compensation is performed, and determining a link test result according to the target test signal waveform includes: Acquire a target test signal waveform transmitted through a target link after simulation compensation is performed; Performing a waveform analysis operation on the target test signal waveform to obtain an analysis result reflecting the target link signal transmission quality, wherein the waveform analysis operation includes at least one of eye diagram analysis, jitter analysis, and amplitude analysis; A link test result is determined based on the analysis result.

13. A computer device, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the link testing method according to any one of claims 1 to 12 when executing the computer program.

14. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, wherein the computer program implements the steps of the link testing method according to any one of claims 1 to 12 when executed by a processor.

15. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the link testing method according to any one of claims 1 to 12 are implemented.

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