Extreme value triggering method and device

Abstract

The invention belongs to the technical field of digital systems, and particularly relates to an extreme value triggering method and device, and the method comprises the steps: starting a first counting process, obtaining a first counting value, judging whether the first counting value is the same as a pre-triggering depth value or not, and if yes, entering a triggering waiting state; starting a second counting process, obtaining a second counting value, judging whether the second counting value is the same as a preset threshold value or not, if not, obtaining a dynamic threshold value from a data point of the waveform data, traversing the data point of the waveform data, judging whether the data point of the waveform data meets a target condition relative to the dynamic threshold value or not, and if yes, executing the second counting process; changing a data point of the waveform data into a dynamic threshold value, and taking a storage position corresponding to the data point of the waveform data as a trigger address; and finishing triggering by taking the current triggering address as a triggering condition until the second count value is the same as the preset threshold value. According to the method, the triggering precision can be greatly improved for signals with variable amplitudes and variable periods, and the possibility of false triggering and missing triggering is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of digital systems, and in particular to an extreme value triggering method and device. Background Art

[0002] The trigger mode is the core function of the digital system, which enables the waveform to be displayed stably and repeatedly on the screen. The common trigger modes of existing digital systems, such as edge, pulse width, slope and other advanced triggers, are based on the core principle of fixed level triggers, but these trigger modes are difficult to stably trigger signals with variable amplitudes and periods.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0004] In view of at least one of the above technical problems, the present application provides an extreme value triggering method and device.

[0005] In a first aspect, an extreme value triggering method is provided, which is applied to a digital system, and includes:

[0006] Obtain a preset trigger position point and obtain a preset time difference, where the preset time difference is the difference between the preset trigger position point and the zero point of the time axis;

[0007] According to the preset time difference and sampling frequency, a preset gate value is obtained, and the sampling frequency is the real-time sampling frequency of the digital system;

[0008] According to the preset gate value, the pre-trigger depth value is obtained;

[0009] Get waveform data;

[0010] Start a first counting process, obtain a first counting value, determine whether the first counting value is the same as the pre-trigger depth value, and if so, enter a waiting trigger state;

[0011] Starting a second counting process, obtaining a second counting value, determining whether the second counting value is the same as a preset threshold value, if not, obtaining a dynamic threshold value from a data point of the waveform data, traversing the data points of the waveform data, determining whether the data points of the waveform data meet the target condition relative to the dynamic threshold value, and if so, changing the data point of the waveform data to the dynamic threshold value, and using the storage location corresponding to the data point of the waveform data as the trigger address;

[0012] Until the second count value is the same as the preset gate value, the trigger is completed with the current trigger address as the trigger condition.

[0013] One of the above technical solutions has at least one of the following advantages or beneficial effects: This method can be used for signals with variable amplitudes and variable periods. By finding the extreme value of the input signal within a certain period of time, the digital system will record this extreme value position as the trigger position, and can stabilize at the extreme value position found, thereby greatly improving the trigger accuracy and reducing the possibility of false triggering and missed triggering.

[0014] In some possible implementations, obtaining a pre-trigger depth value according to a preset gate value includes the following steps:

[0015] According to the preset gate value and based on the first formula, a pre-trigger depth value is generated;

[0016] The first formula is: deep_num = num * L

[0017] Among them, deep_num is the pre-trigger depth value, num is the preset gate value, and L is the number of parallel paths.

[0018] In some possible implementations, the number of parallel paths is the sampling frequency divided by the FPGA master clock frequency.

[0019] In some possible implementations, the target conditions include: a maximum value target and a minimum value target.

[0020] In some possible implementations, determining whether a data point of the waveform data meets a target condition relative to a dynamic threshold value includes the following steps:

[0021] If not, the dynamic threshold remains unchanged and the trigger address remains unchanged.

[0022] In some possible implementations, the digital system includes a first counter and a second counter, the first counter is used to generate a first count value, and the second counter is used to generate a second count value.

[0023] In some possible implementations, the first counter and the second counter operate asynchronously.

[0024] In some possible implementations, the digital system includes an ADC and a filter, the ADC is used to acquire waveform data, and the filter is used to perform high-frequency filtering on the waveform data.

[0025] In a second aspect, an extreme value triggering device is provided, comprising:

[0026] The preset module is used to obtain a preset trigger position point and obtain a preset time difference, where the preset time difference is the difference between the preset trigger position point and the zero point of the time axis; obtain a preset gate value according to the preset time difference and the sampling frequency, where the sampling frequency is the real-time sampling frequency of the digital system; and obtain a pre-trigger depth value according to the preset gate value;

[0027] An acquisition module, used for acquiring waveform data;

[0028] A preparation module, used to start a first counting process, obtain a first counting value, determine whether the first counting value is the same as the pre-trigger depth value, and if so, enter a waiting trigger state;

[0029] A trigger module is used to start a second counting process, obtain a second counting value, determine whether the second counting value is the same as a preset gate value, and if not, obtain a dynamic threshold value from a data point of the waveform data, traverse the data points of the waveform data, and determine whether the data points of the waveform data meet the target conditions relative to the dynamic threshold value. If so, change the data point of the waveform data to the dynamic threshold value, and use the storage location corresponding to the data point of the waveform data as the trigger address; until the second counting value is the same as the preset gate value, the current trigger address is used as the trigger condition to complete the trigger.

[0030] In some possible implementations, determining whether a data point of the waveform data meets a target condition relative to a dynamic threshold value includes the following steps:

[0031] If not, the dynamic threshold remains unchanged and the trigger address remains unchanged.

[0032] The present application is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art will be briefly introduced below. 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 paying creative work.

[0034] Figure 1 A flowchart of the extreme value triggering method provided in the embodiment of the present application;

[0035] Figure 2 A structural block diagram of an extreme value triggering device provided in an embodiment of the present application; DETAILED DESCRIPTION

[0036] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0037] The core principle of the common triggering methods of existing digital systems, such as edge, pulse width, slope and other advanced triggering, is based on the triggering of fixed level. However, these triggering methods are difficult to stably trigger signals with variable amplitude and variable period. This method can be used for signals with variable amplitude and variable period. By finding the extreme value of the input signal within a certain period of time, the digital system will record this extreme value position as the trigger position, and can stabilize at the extreme value position found, which greatly improves the triggering accuracy and reduces the possibility of false triggering and missed triggering.

[0038] like Figure 1 As shown, an embodiment of the present application provides an extreme value triggering method, which is applied in a digital system, and includes: steps S100 to S700.

[0039] The digital system includes signal processing function, data storage function, data transmission function, calculation and control function. The digital system may include a signal generator, a logic analyzer, a spectrum analyzer, a digital multimeter, a data acquisition system and an oscilloscope, which are not specifically limited here. In this embodiment, the digital system is an oscilloscope.

[0040] S100, obtaining a preset trigger position point and obtaining a preset time difference, where the preset time difference is the difference between the preset trigger position point and the zero point of the time axis.

[0041] S200, obtaining a preset gate value according to a preset time difference and a sampling frequency, wherein the sampling frequency is a real-time sampling frequency of a digital system.

[0042] S300, obtaining a pre-trigger depth value according to a preset gate value.

[0043] In this step, a pre-trigger depth value is generated according to a preset gate value and based on a first formula;

[0044] The first formula is: deep_num = num * L

[0045] Among them, deep_num is the pre-trigger depth value, num is the preset gate value, and L is the number of parallel paths.

[0046] The number of parallel paths is the sampling frequency divided by the FPGA master clock frequency.

[0047] S400, acquiring waveform data.

[0048] S500, start a first counting process, obtain a first counting value, determine whether the first counting value is the same as the pre-trigger depth value, and if so, enter a waiting trigger state;

[0049] In this step, if the first count value is less than the pre-trigger depth value, the trigger state is not entered, and the second count process is not started. In other words, the second count process requires the system to enter the waiting trigger state before it can start.

[0050] S600, start the second counting process, obtain the second counting value, determine whether the second counting value is the same as the preset gate value, if not, obtain the dynamic threshold value from a data point of the waveform data, traverse the data points of the waveform data, and determine whether the data points of the waveform data meet the target conditions relative to the dynamic threshold value. If so, change the data point of the waveform data to the dynamic threshold value, and use the storage location corresponding to the data point of the waveform data as the trigger address; if not, the dynamic threshold value remains unchanged, and the trigger address remains unchanged.

[0051] Among them, the target conditions include: maximum value target and minimum value target. The maximum value target is triggered by the maximum value of the waveform data. When the data point of the waveform data is greater than the dynamic threshold, the data point of the waveform data is changed to the dynamic threshold, and the storage location corresponding to the data point of the waveform data is used as the trigger address. The minimum value target is triggered by the minimum value of the waveform data. When the data point of the waveform data is less than the dynamic threshold, the data point of the waveform data is changed to the dynamic threshold, and the storage location corresponding to the data point of the waveform data is used as the trigger address.

[0052] When the target condition is the maximum value target, and the first three data points of the waveform data are taken as an example. The first three data points of the waveform data are the first data point, the second data point and the third data point. The first data point is used as the dynamic threshold, and then the second data point is compared with the dynamic threshold, that is, the second data point is compared with the first data point. If the second data point is larger than the dynamic threshold, the second data point is changed to the dynamic threshold, and the storage location corresponding to the second data point is used as the trigger address.

[0053] Then, the third data point is compared with the dynamic threshold, that is, the third data point is compared with the second data point. If the third data point is larger than the dynamic threshold, the third data point is changed to the dynamic threshold, and the storage location corresponding to the second data point is used as the trigger address. If the third data point is smaller than the dynamic threshold, the dynamic threshold remains unchanged, and the trigger address remains unchanged.

[0054] S700, until the second count value is the same as the preset gate value, the current trigger address is used as the trigger condition to complete the triggering.

[0055] In step 600, the extreme value search time may also be set, that is, the extreme value triggering method of this embodiment may further include the following steps:

[0056] Preset extreme value search time;

[0057] When the second counting process starts, start timing;

[0058] When the timing time is the same as the preset search time, the current trigger address is output and the current trigger address is used as the trigger condition;

[0059] The timer is reset to zero.

[0060] By setting the extreme value search time, it can adapt to the real-time output of any continuous signal extreme value point, and can be used for extreme value calibration or synchronization of digital systems.

[0061] In some embodiments, the digital system includes a first counter and a second counter, wherein the first counter is used to generate a first count value, and the second counter is used to generate a second count value. The first counter and the second counter operate asynchronously.

[0062] In some embodiments, the digital system includes an ADC and a filter, the ADC is used to obtain waveform data, and the filter is used to perform high-frequency filtering on the waveform data. The filter is not specifically limited, and the filter may include a low-pass filter, a hysteresis filter, a high-pass filter, a band-pass filter, and a band-stop filter, all of which can filter out interference or noise, thereby improving the accuracy of extreme value search.

[0063] In this embodiment, the filter is a low-pass filter.

[0064] like Figure 2 As shown, the embodiment of the present application also provides an extreme value triggering device, including:

[0065] The preset module 100 is used to obtain a preset trigger position point and obtain a preset time difference, where the preset time difference is the difference between the preset trigger position point and the zero point of the time axis; obtain a preset gate value according to the preset time difference and the sampling frequency, where the sampling frequency is the real-time sampling frequency of the digital system; and obtain a pre-trigger depth value according to the preset gate value;

[0066] An acquisition module 200, used for acquiring waveform data;

[0067] A preparation module 300 is used to start a first counting process, obtain a first count value, determine whether the first count value is the same as the pre-trigger depth value, and if so, enter a waiting trigger state;

[0068] The trigger module 400 is used to start the second counting process, obtain the second counting value, determine whether the second counting value is the same as the preset gate value, if not, obtain the dynamic threshold value from a data point of the waveform data, traverse the data points of the waveform data, and determine whether the data points of the waveform data meet the target conditions relative to the dynamic threshold value. If so, change the data point of the waveform data to the dynamic threshold value, and use the storage location corresponding to the data point of the waveform data as the trigger address; if not, the dynamic threshold value remains unchanged, and the trigger address remains unchanged. Until the second counting value is the same as the preset gate value, the current trigger address is used as the trigger condition, and the trigger is completed.

[0069] In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0070] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0071] In addition, various aspects or features of the present application can be implemented as methods, devices or products using standard programming and / or engineering techniques. The term "product" used in this application covers computer programs that can be accessed from any computer-readable device, carrier or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks or tapes, etc.), optical disks (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards and flash memory devices (e.g., erasable programmable read-only memory (EPROM), cards, sticks or key drives, etc.). In addition, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing and / or carrying instructions and / or data.

[0072] It should also be understood that in the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0073] Those of ordinary skill in the art will 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 composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0074] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0075] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described below are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or can be electrical, mechanical or other forms of connection.

[0076] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0077] The above are only preferred embodiments of the present application, and do not constitute any formal limitation on the present application. Any technician familiar with the art can use the above disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment of equivalent changes. Therefore, all equivalent changes made according to the shape, structure and principle of the present application without departing from the content of the technical solution of the present application should be included in the protection scope of the present application.

Claims

1. An extreme value triggering method, applied in a digital system, characterized in that: include: Acquire a preset trigger position point and obtain a preset time difference, where the preset time difference is the difference between the preset trigger position point and the zero point of the time axis; A preset gate value is obtained according to a preset time difference and a sampling frequency, wherein the sampling frequency is a real-time sampling frequency of a digital system; According to the preset gate value, the pre-trigger depth value is obtained; Get waveform data; Starting a first counting process, obtaining a first counting value, determining whether the first counting value is the same as the pre-trigger depth value, and if so, entering a waiting trigger state; Starting a second counting process, obtaining a second counting value, determining whether the second counting value is the same as the preset threshold value, if not, obtaining a dynamic threshold value from a data point of the waveform data, traversing the data points of the waveform data, determining whether the data point of the waveform data meets the target condition relative to the dynamic threshold value, and if so, changing the data point of the waveform data to the dynamic threshold value, and using the storage location corresponding to the data point of the waveform data as the trigger address; Until the second count value is the same as the preset gate value, the trigger is completed with the current trigger address as the trigger condition.

2. The extreme value triggering method according to claim 1, characterized in that: The method of obtaining the pre-trigger depth value according to the preset gate value comprises the following steps: According to the preset gate value and based on the first formula, a pre-trigger depth value is generated; The first formula is: deep_num=num*L Among them, deep_num is the pre-trigger depth value, num is the preset gate value, and L is the number of parallel paths.

3. The extreme value triggering method according to claim 2, characterized in that: The number of parallel paths is the sampling frequency divided by the FPGA main clock frequency.

4. The extreme value triggering method according to claim 1, characterized in that: The target conditions include: a maximum value target and a minimum value target.

5. The extreme value triggering method according to claim 1, characterized in that: The step of determining whether a data point of the waveform data meets a target condition relative to the dynamic threshold comprises the following steps: If not, the dynamic threshold remains unchanged, and the trigger address remains unchanged.

6. The extreme value triggering method according to claim 1, characterized in that: The digital system includes a first counter and a second counter, wherein the first counter is used to generate a first count value, and the second counter is used to generate a second count value.

7. The extreme value triggering method according to claim 6, characterized in that: The first counter operates asynchronously with the second counter.

8. The extreme value triggering method according to claim 1, characterized in that: The digital system includes an ADC and a filter, wherein the ADC is used to acquire waveform data, and the filter is used to perform high-frequency filtering on the waveform data.

9. An extreme value triggering device, characterized in that: include: A preset module, used to obtain a preset trigger position point and obtain a preset time difference, wherein the preset time difference is a difference between the preset trigger position point and the zero point of the time axis; According to the preset time difference and the sampling frequency, a preset gate value is obtained, wherein the sampling frequency is the real-time sampling frequency of the digital system; according to the preset gate value, a pre-trigger depth value is obtained; An acquisition module, used for acquiring waveform data; A preparation module, used to start a first counting process, obtain a first counting value, determine whether the first counting value is the same as the pre-trigger depth value, and if so, enter a waiting trigger state; a trigger module, used to start a second counting process, obtain a second counting value, determine whether the second counting value is the same as the preset threshold value, if not, obtain a dynamic threshold value from a data point of the waveform data, traverse the data points of the waveform data, determine whether the data point of the waveform data meets the target condition relative to the dynamic threshold value, and if so, change the data point of the waveform data to the dynamic threshold value, and use the storage location corresponding to the data point of the waveform data as the trigger address; Until the second count value is the same as the preset gate value, the trigger is completed with the current trigger address as the trigger condition.

10. The extreme value triggering device according to claim 9, characterized in that: The step of determining whether a data point of the waveform data meets a target condition relative to the dynamic threshold comprises the following steps: If not, the dynamic threshold remains unchanged, and the trigger address remains unchanged.

Images