Simulation test method, storage medium and simulation test equipment
By fitting linear and exponential excitation waveforms, and dynamically adjusting the time interval of target segmentation samples, the target excitation waveforms are generated for simulation testing, the problem of difficulty in simulating complex waveform changes in the existing technology is solved, and the accuracy and calculation efficiency of simulation results are improved.
Patent Information
- Application Number
- CN202411924774.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-04-22
AI Technical Summary
Existing simulation testing methods are difficult to accurately and flexibly simulate complex types of waveform changes, resulting in low accuracy of simulation results.
By fitting the linear excitation waveform and the exponential excitation waveform, the initial excitation waveform is obtained, and the time interval of the target segmentation sample points is dynamically adjusted in the initial excitation waveform to generate the target excitation waveform for simulation testing.
It improves the accuracy of simulation results, can capture the details of complex waveform changes more accurately, improves waveform distortion problems, and takes into account calculation efficiency.
Smart Images
Figure CN119861275A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of simulation testing, specifically to simulation testing of integrated circuit standard units, and more particularly to a simulation testing method, storage medium, and simulation testing equipment. Background Art
[0002] The characteristic parameter extraction of standard cells is an important process of simulation testing. It refers to inputting an excitation waveform into the standard cell during the circuit design process, and simulating the timing, power consumption, noise and other characteristic parameters of the standard cell through the simulator. In this process, the change of the excitation waveform directly determines the accuracy of the simulation results. There are two main types of excitation waveforms: linear excitation waveform, that is, the excitation waveform obtained by a linear function; exponential excitation waveform, that is, the excitation waveform obtained by an exponential function.
[0003] Both of these excitation waveforms are generated based on the equally spaced point method, that is, a point is determined at a fixed time interval, and these sample points are connected in sequence to form the corresponding excitation waveform. However, when simulating complex types of waveform changes, such as areas where the waveform changes faster and slower, the sample point density is the same, which obviously makes it difficult to capture the details of the signal change, resulting in the so-called waveform distortion problem, which makes it impossible to accurately reflect the signal characteristics in the actual circuit, affecting the accuracy of the simulation results.
[0004] In addition, the actual circuit signals of standard cells often change nonlinearly, which makes it easy for errors to occur between the linear excitation waveform and the actual circuit signal. Especially when simulating complex types of waveform changes, the details of the signal changes cannot be captured. For example, in small-size circuits, the resistance and capacitance effects of metal traces are more prominent, and the signal will have a steep rising edge, small fluctuations or noise. These details are very easy to be ignored or smoothed out in the process of outputting the linear excitation waveform, resulting in a large deviation between the simulation results and the actual signal, waveform distortion problems, and affecting the accuracy of the simulation results.
[0005] The exponential excitation waveform only uses a single exponential function to simulate the signal, and it is also difficult to accurately and flexibly simulate complex types of waveform changes, resulting in low accuracy of the simulation results. Summary of the invention
[0006] In view of this, the present application provides a simulation test method, storage medium, and simulation test equipment, which can improve the problem that the existing simulation test method based on equally spaced points is difficult to accurately and flexibly simulate complex types of waveform changes, and the resulting low accuracy of the simulation results.
[0007] A simulation test method provided by the present application includes:
[0008] Determine linear excitation waveform and exponential excitation waveform;
[0009] Fitting the linear excitation waveform and the exponential excitation waveform to obtain an initial excitation waveform;
[0010] A plurality of target segmentation sample points are obtained in the initial excitation waveform, wherein the time intervals between any two adjacent target segmentation sample points are not equal or are partially equal;
[0011] Obtaining a target excitation waveform according to the plurality of target segmentation sample points;
[0012] A simulation test is performed based on the target excitation waveform.
[0013] Optionally, the linear excitation waveform and the exponential excitation waveform are fitted by the following relationship:
[0014] f(t)=(1-k)*f 1 (t)+k*f 2 (t)
[0015] Among them, f(t) is the function used when outputting the initial excitation waveform, t is time, k is the fitting proportional coefficient, and it satisfies 0<k<1, f 1 (t) is the function used when outputting the exponential excitation waveform, f 2 (t) is the linear function used when outputting the linear excitation waveform.
[0016] Optionally, the method further includes:
[0017] The fitting proportionality coefficient k is adjusted to obtain an adjusted initial excitation waveform.
[0018] Optionally, the exponential excitation waveform is outputted through the following relationship:
[0019]
[0020] Among them, V dd is the power supply voltage, e xp is the exponential function, that is, the exp function, t exp and t RC Both are time parameters calculated based on preset voltage threshold parameters and input parameters.
[0021] Optionally, obtaining a plurality of target segmentation sample points in the initial excitation waveform includes:
[0022] S31, selecting a number of candidate sample points;
[0023] S32, calculating a preset distance between each candidate sample point and a preset line, where the preset line is a straight line between a start point and an end point of a corresponding waveform;
[0024] S33, determining a candidate sample point with the largest preset distance and using it as a key segmentation sample point;
[0025] S34, segmenting the initial excitation waveform using the key segmentation sample points;
[0026] Repeating S31 to S34 for each segmented waveform obtained by segmentation, until the total number of the key segmentation sample points reaches a preset threshold;
[0027] The key segmentation sample points of the preset threshold are all used as target segmentation sample points.
[0028] Optionally, the time interval between any two adjacent candidate sample points, the time interval between the starting point and an adjacent candidate sample point, and the time interval between the end point and an adjacent candidate sample point are all equal.
[0029] Optionally, the preset distance is a vertical distance or a vertical distance, and the vertical distance is a distance along the y-axis direction.
[0030] Optionally, obtaining a target excitation waveform according to the multiple target segmentation sampling points includes:
[0031] The plurality of target segmentation sample points are connected in sequence to obtain a target excitation waveform.
[0032] The present application provides a storage medium storing a simulation test program, which, when executed by a processor, implements the steps of the simulation test method as described in any one of the above items.
[0033] The present application provides a simulation test device, including the storage medium as described above.
[0034] As described above, the present application fits a linear excitation waveform and an exponential excitation waveform to obtain an initial excitation waveform, which is equivalent to using multiple functions to perform signal simulation. By adjusting the fitting proportional coefficient, complex types of waveform changes can be simulated more accurately and flexibly, thereby improving the accuracy of the simulation results. In addition, when generating the target excitation waveform, the time intervals between any two adjacent target segmentation sample points are not equal or partially equal, which is equivalent to generating the target excitation waveform based on unequally spaced point sampling methods, which is conducive to dynamically adjusting the point sampling interval according to the information of the initial excitation waveform changes. For example, in areas where the waveform changes faster, the point sampling density is increased to capture the details of the waveform changes, improve the waveform distortion problem, and improve the accuracy of the simulation results; in areas where the waveform changes slower, the point sampling density is reduced to improve computational efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1It is a flowchart of a simulation test method according to an embodiment of the present application;
[0036] Figure 2 is a schematic diagram of three initial excitation waveforms obtained based on three fitting proportional coefficients k in the present application;
[0037] Figure 3 It is a flowchart of a method for obtaining multiple target segmentation sample points in this application;
[0038] Figure 4 This is a schematic diagram of the present application performing multiple segmentations based on candidate sampling points to obtain multiple target segmentation sample points. DETAILED DESCRIPTION
[0039] In order to solve the above existing technical problems, the present application provides a simulation test method, storage medium, and simulation test equipment. These protection themes are based on the same concept, and the principles of solving the problems are basically the same or similar. The implementation methods of each protection theme can refer to each other, and the repeated parts will not be repeated.
[0040] In each example of the present application, a linear excitation waveform and an exponential excitation waveform are fitted to obtain an initial excitation waveform, which is equivalent to using multiple functions to perform signal simulation, and by adjusting the fitting proportional coefficient, complex types of waveform changes can be accurately and flexibly simulated; in addition, when generating a target excitation waveform, the time interval between any two adjacent target segmentation sample points is unequal or partially equal, which is equivalent to generating a target excitation waveform based on an unequally spaced point-taking method, and dynamically adjusting the point-taking interval according to the information of the initial excitation waveform changes to capture the details of the waveform changes while taking into account computational efficiency.
[0041] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly described below in conjunction with specific embodiments and corresponding drawings. Obviously, the embodiments described below are only part of the embodiments of the present application, not all of the embodiments. In the absence of conflict, the following embodiments and their technical features can be combined with each other and also belong to the technical solutions of the present application.
[0042] See also Figure 1 As shown, a simulation test method according to an embodiment of the present application, which may be referred to as a “method” for short, includes at least the following steps S1 to S5.
[0043] S1: Determine the linear excitation waveform and the exponential excitation waveform.
[0044] Both the linear excitation waveform and the exponential excitation waveform describe the mapping relationship between the output voltage and time.
[0045] In one example, the linear excitation waveform may be an excitation waveform obtained based on NLDM (non linear delay model). When the model is excited, the driving end of the simulation circuit is equivalent to a voltage source with a constant internal resistance, and the receiving end of the simulation circuit is equivalent to a capacitor, where the output voltage is a linear function of time. The linear excitation waveform may be obtained as follows:
[0046] First, determine two adjacent or non-adjacent sample points, that is, determine two threshold points, for example, according to the power supply voltage V dd And the relation n 1 *V dd Determine a threshold point based on the power supply voltage V dd And the relation n 2 *V dd Determine another threshold point, where n 1 and n 2 are all preset voltage threshold parameters, and n 1 Less than n 2 , and both are greater than zero and less than 1; for the power supply voltage V dd When it is 1.8V, n 1 =0.3, n 2 =0.7, the two sample points are determined to be 0.54V and 1.26V respectively; then, the time corresponding to each sample point is set according to the simulation requirements, that is, the time t when the waveform signal reaches one of the sample points is determined 1 , and the time t to reach another sample point 2 , to obtain the time difference (t 2 -t 1 ); then, according to the time difference (t 2 -t 1 ) and the voltage values of the two sample points (n 1 *V dd )、(n 2 *V dd ), through the relationship S = ((n 2 *V dd )-(n 1 *V dd )) / (t 2 -t 1 ) to determine the slope S; finally, according to the slope S, the linear excitation waveform can be determined.
[0047] In one example, the exponential excitation waveform may be an excitation waveform obtained based on CCS (Code Composer Studio, code debugger), and the acquisition method may be as follows:
[0048] First, determine a number of sample points. The time interval between any two adjacent sample points is equal, that is, the sample points are determined by taking points at equal intervals. The determination method of each sample point can refer to the aforementioned linear excitation waveform, that is, n*V dd , n is greater than zero and less than 1; then, set relevant parameters according to simulation requirements, such as the power supply voltage V dd , the rise time t between adjacent sample points l And the fall time t h , high level and low level; then, based on these parameters, use the exponential function e xp , and generate a response waveform through the following relationship to describe the exponential change from the initial voltage to the target voltage, that is, the output exponential excitation waveform.
[0049]
[0050] Among them, f 1 (t) is the function used to output the exponential excitation waveform, and its output value is the voltage value, t is the time, e xp is the exponential function, that is, the exp function, t RC is based on the preset voltage threshold parameter (i.e. the aforementioned n 1 and n 2 ) and the input parameters are logarithmically transformed to obtain the time parameter used to determine f 1 (t) rate of change; t exp According to t RC After the input parameters are logarithmically transformed again, the time parameters calculated are used to determine f 1 The input parameter can be freely set by the user, for example, the time difference (t 2 -t 1 The specific process and principle of the logarithmic transformation can be determined according to the actual adaptability required, and this application does not limit it.
[0051] S2: Fit the linear excitation waveform and the exponential excitation waveform to obtain the initial excitation waveform.
[0052] In one example, the linear excitation waveform and the exponential excitation waveform are fitted by the following relationship:
[0053] f(t)=(1-k)*f 1 (t)+k*f 2 (t)
[0054] Among them, f(t) is the function used when outputting the initial excitation waveform, k is the fitting proportional coefficient, and it satisfies 0<k<1, f 1 The method of obtaining (t) can refer to the above S1, f 2(t) is the linear function used when outputting the linear excitation waveform, and its input value includes the slope S.
[0055] The fitting proportional coefficient k is an adjustable coefficient. Here, the simulation test method of the present application may further include the step of adjusting the fitting proportional coefficient k to obtain an adjusted initial excitation waveform. For the simulation test equipment in the actual scene, an intuitive input interface can be used to allow the user to freely adjust the exponential function f 1 (t) and the linear function f 2 The fitting ratio of (t) is adjusted to generate a continuously changing waveform from a linear excitation waveform to an exponential excitation waveform, thereby achieving a smooth transition of the waveform. This can not only obtain more accurate simulation results, but also greatly increase the flexibility of the simulation test and can adapt to various simulation test requirements.
[0056] Figure 2 Schematic diagram of three initial excitation waveforms obtained based on three fitting proportional coefficients k in this application. Figure 2 In the plane rectangular coordinate system shown, the horizontal axis is time t, the unit is nanosecond, and the vertical axis is voltage V, the unit is volt. Figure 2 As shown, the initial excitation waveform L 1 The corresponding fitting proportional coefficient k is equal to 0. At this time, the initial excitation waveform L 1 It can be regarded as an exponential excitation waveform; the initial excitation waveform L 2 The corresponding fitting proportional coefficient k is equal to 1. At this time, the initial excitation waveform L 2 It can be regarded as a linear excitation waveform; when the fitting ratio k is equal to 0.5, the corresponding initial excitation waveform L 3 .
[0057] S3: obtaining a plurality of target segmentation sample points in the initial excitation waveform, wherein the time intervals between any two adjacent target segmentation sample points are not equal or are partially equal.
[0058] The target segmentation point is a sample point selected from the initial excitation waveform, and the final required excitation waveform, i.e., the target excitation waveform, is obtained by reconnecting these selected sample points in a straight line. Here, the target segmentation point can be regarded as the intersection of the initial excitation waveform and the target excitation waveform.
[0059] In one example, if Figure 3 As shown, multiple target segmentation sample points can be obtained by the following methods, including:
[0060] S31, selecting a number of candidate sample points;
[0061] S32, calculating a preset distance between each candidate sample point and a preset line, where the preset line is a straight line between a start point and an end point of a corresponding waveform;
[0062] S33, determining a candidate sample point with the largest preset distance and using it as a key segmentation sample point;
[0063] S34, segmenting the initial excitation waveform through key segmentation sample points;
[0064] Repeating S31 to S34 for each segmented waveform obtained by segmentation;
[0065] S35, determining whether the total number of key segmentation sample points reaches a preset threshold;
[0066] If yes, then execute S36 to take all the key segmentation sample points with the preset threshold as the target segmentation sample points.
[0067] If not, then for each segmented waveform obtained by segmentation, the steps S31 to S34 are repeatedly executed respectively until the total number of key segmentation sample points reaches a preset threshold, and then the step S36 is executed.
[0068] Combination Figure 4 As shown, the first candidate sample point is selected: in the initial excitation waveform L 0 A number of candidate sampling points are selected, and the number of candidate sampling points can be determined according to the adaptability of actual needs, and is not limited in this application; the time interval between any two adjacent candidate sampling points (referred to as the "first time interval") is equal. In addition, the initial excitation waveform L 0 The time interval between the starting point of and the nearest candidate sample point is called the "second time interval". 0 The time interval between the end point and the most adjacent candidate sample point is called the "third time interval", and the first time interval, the second time interval and the third time interval are all equal, that is, the present application adopts an equidistant point selection method to determine a number of candidate sample points.
[0069] After the candidate sample point is selected for the first time, the preset line L in S32 01 is the initial excitation waveform L 0 In S33, the preset distance is a vertical distance, or a vertical distance, and the vertical distance can be understood as the distance between the candidate sample point and the preset connection line L. 01 The minimum distance between the two or the straight-line distance, for example, see Figure 4 The dotted line d 02 The vertical distance is the distance between the candidate sample point and the preset line L along the y-axis direction. 01 The straight-line distance between Figure 4 The dotted line d 01 For the first selected multiple candidate sample points, the vertical distance d 02Taking the preset distance as an example, the step S33 determines the candidate sample point P 1 As the key segmentation sample point P 1 .
[0070] If the key segmentation sample point P is determined 1 After that, the subsequent segmentation is ended. At this time, the key segmentation sample point P 1 With the initial excitation waveform L 0 The connecting straight line between the starting points and the key segmentation sample point P 1 With the initial excitation waveform L 0 The connecting straight line between the end points constitutes the target excitation waveform L 02 .
[0071] If the key segmentation sample point P is determined 1 After that, the segmentation is continued, and the second selection of candidate sample points is performed: the S34 is performed by the key segmentation sample point P 1 , the initial excitation waveform L 0 Then, according to the method of S31, select a number of candidate sample points on each segmented waveform; then, according to the method of S32, calculate the preset distance between each candidate sample point and the preset connection line. It should be noted that the preset connection line this time is the straight line between the starting point and the end point of each segmented waveform; according to the method of S33, determine the key segmentation sample points on each segmented waveform. Two key segmentation sample points are obtained in the second determination, which are Figure 4 The arrow points to P 2 and P 3 .
[0072] If the key segmentation sample point P is determined 2 and P 3 After that, the subsequent segmentation is ended. At this time, the key segmentation sample point P 3 With the initial excitation waveform L 0 The connecting straight line between the starting points, the key segmentation sample point P 2 and P 3 The connecting straight line between them, and the key segmentation sample point P 2 With the initial excitation waveform L 0 The connecting straight line between the end points constitutes the target excitation waveform (not shown in the figure).
[0073] If the key segmentation sample point P is determined 2 and P 3 After that, the segmentation is continued, and the steps S31 to S34 are repeated for each segmented waveform obtained by the second segmentation. Through multiple segmentation iterations, until the total number of key segmentation points reaches a preset threshold, the key segmentation points of the preset threshold are all used as target segmentation points, and the following S4 is executed.
[0074] The number of target segmentation points obtained each time is less than the number of candidate points determined each time; the number of target segmentation points finally obtained, that is, the preset threshold, is less than the total number of candidate points determined by multiple segmentations.
[0075] The larger the preset threshold is, the more target segmentation samples are obtained, and the initial excitation waveform L 0 The finer the segmentation processing, the better it can capture the initial excitation waveform L 0 Details of changes.
[0076] S4: Obtain a target excitation waveform according to a plurality of target segmentation sampling points.
[0077] The target excitation waveform can be obtained by sequentially connecting the multiple target segmentation sample points obtained in S3 with straight lines. It can be seen that in the target excitation waveform, the distance between two adjacent target segmentation sample points changes linearly.
[0078] S5: Perform simulation test based on target excitation waveform.
[0079] The specific principle and process of the simulation test can be referred to the prior art in the art, and will not be described in detail here. In short, the input voltage of the voltage source is controlled according to the "voltage-time" relationship between two adjacent target segmentation sample points.
[0080] As described above, the present application fits a linear excitation waveform and an exponential excitation waveform to obtain an initial excitation waveform, which is equivalent to using multiple functions to perform signal simulation. By adjusting the fitting proportional coefficient, complex types of waveform changes can be simulated more accurately and flexibly, thereby improving the accuracy of the simulation results. In addition, when generating the target excitation waveform, the time intervals between any two adjacent target segmentation sample points are not equal or partially equal, which is equivalent to generating the target excitation waveform based on unequally spaced point sampling methods, which is conducive to dynamically adjusting the point sampling interval according to the information of the initial excitation waveform changes. For example, in areas where the waveform changes faster, the point sampling density is increased to capture the details of the waveform changes, improve the waveform distortion problem, and improve the accuracy of the simulation results; in areas where the waveform changes slower, the point sampling density is reduced to improve computational efficiency.
[0081] It should be noted that, for the method of any of the above embodiments of the present application, although step codes such as S1, S2, etc. are used, their purpose is to express the corresponding content more clearly and concisely, and do not constitute a substantial limitation on the sequence. When implementing it specifically, those skilled in the art may execute S3 first and then S2, etc., but these should all be within the scope of protection of the present application.
[0082] An embodiment of the present application also provides a storage medium on which a simulation test program is stored. When the simulation test program is executed by a processor, the steps of the simulation test method as in any example are implemented.
[0083] The storage medium includes but is not limited to any one of a read-only memory (ROM), a random access memory (RAM), a magnetic disk and an optical disk.
[0084] Since the program stored in the storage medium can execute the steps in the simulation test method of any embodiment provided in the present application, the beneficial effects that can be achieved by the simulation test method of any of the aforementioned embodiments can be achieved. Please see the aforementioned embodiments for details and will not be repeated here.
[0085] An embodiment of the present application also provides an intelligent device or chip, including a memory and a processor, wherein a simulation test program is stored in the memory, and when the simulation test program is executed by the processor, the steps of the simulation test method of any of the aforementioned embodiments are implemented; and / or, the intelligent device or chip is provided with a storage medium as exemplified above, and the processor of the intelligent device or chip loads the storage medium to execute the steps of the simulation test method, thereby realizing the beneficial effects that can be achieved by the simulation test method of the corresponding embodiment.
[0086] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. For ordinary technicians in this field, all equivalent structural changes made using the contents of this specification and drawings are also included in the patent protection scope of the present application.
[0087] Although the terms "first, second", etc. are used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. In addition, the singular forms "one", "an", and "the" are intended to include plural forms as well. The terms "or" and "and / or" are interpreted as inclusive, or mean any one or any combination. Only when the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way, an exception to this definition will occur.
Claims
1. A simulation test method, characterized in that: Including: Determine a linear excitation waveform and an exponential excitation waveform; Fit the linear excitation waveform and the exponential excitation waveform to obtain an initial excitation waveform; Obtain a plurality of target segmentation sample points from the initial excitation waveform, wherein the time intervals between any two adjacent target segmentation sample points are not equal or partially equal; Obtain a target excitation waveform according to the plurality of target segmentation sample points; Perform a simulation test based on the target excitation waveform.
2. The simulation test method according to claim 1, characterized in that: The linear excitation waveform and the exponential excitation waveform are fitted by the following relational expression: f(t) = (1 - k)*f1(t) + k*f2(t) where f(t) is the function used when outputting the initial excitation waveform, t is time, k is a fitting proportionality coefficient and satisfies 0 < k < 1, f1(t) is the function used when outputting the exponential excitation waveform, and f2(t) is the linear function used when outputting the linear excitation waveform.
3. The simulation test method according to claim 2, characterized in that: The method further includes: Adjust the fitting proportionality coefficient k to obtain an adjusted initial excitation waveform.
4. The simulation test method according to claim 2 or 3, characterized in that: The exponential excitation waveform is output by the following relational expression: Among them, V dd is the power supply voltage, e xp is an exponential function, t exp and t RC Both are time parameters calculated based on preset voltage threshold parameters and input parameters.
5. The simulation test method according to claim 1, characterized in that: The step of obtaining a plurality of target segmentation sample points from the initial excitation waveform includes: S31. Select a number of candidate sample points; S32. Calculate the preset distance between each candidate sample point and a preset connection line, where the preset connection line is a straight line between the starting point and the ending point of the corresponding waveform; S33. Determine a candidate sample point with the largest preset distance and use it as a key segmentation sample point; S34. Segment the initial excitation waveform through the key segmentation sample point; For each segmented waveform obtained, repeat the steps S31 to S34 until the total number of key segmentation sample points reaches a preset threshold; All key segmentation sample points of the preset threshold are used as target segmentation sample points.
6. The simulation test method according to claim 5, characterized in that: The time intervals between any two adjacent candidate sample points, the time interval between the starting point and an adjacent candidate sample point, and the time interval between the ending point and an adjacent candidate sample point are all equal.
7. The simulation test method according to claim 5, characterized in that: The preset distance is a vertical distance or a vertical distance, and the vertical distance is the distance along the y-axis direction.
8. The simulation test method according to any one of claims 5 to 7, characterized in that: The step of obtaining a target excitation waveform according to the plurality of target segmentation sample points includes: Connect the plurality of target segmentation sample points in sequence to obtain a target excitation waveform.
9. A storage medium, characterized in that: A simulation test program is stored, and when the simulation test program is executed by a processor, the steps of the simulation test method according to any one of claims 1 to 8 are implemented.
10. A simulation test device, characterized in that: Including a storage medium as described in claim 9.