Isochronous control method and device for differential pair, equipment and storage medium

Abstract

The application relates to the technical field of electronic circuits, and provides an isochronous control method and device for a differential pair, equipment and a storage medium. An initial time delay difference of a surface layer differential pair is obtained; and at least one of the following adjustment operations is performed according to the initial time delay difference to obtain a differential pair with a time delay difference meeting isochronous control requirements of the differential pair: the width of a first trace is adjusted from an initial width to a first width, the first width being greater than the initial width; the width of a second trace is adjusted from the initial width to a second width, the second width being less than the initial width; and the height between the second trace and a reference layer is adjusted from an initial height to a target height. The width of the trace of the surface layer differential pair and the distance between a single wire in the differential pair and the reference layer are adjusted, so that the differential pair with the time delay difference meeting the isochronous control requirements of the differential pair is obtained, the integrity of signals is ensured on the basis of meeting the isochronous control requirements of the time delay difference, and the signal quality of the differential pair is improved.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to an isochronous control method, apparatus, device and storage medium for differential pairs. Background Technology

[0002] Currently, when using differential pairs for the design of large-scale, high-density printed circuit boards (PCBs), there are strict requirements for the isochronous control of the differential pairs.

[0003] In related technologies, a common approach is to use layered serpentine routing to alter the absolute length of individual lines in a differential pair located on the inner layer of the PCB, thereby changing the signal transmission delay of the corresponding line and achieving isochronous control of the differential pair. However, the delay difference obtained by this method may still be significant, failing to meet the isochronous control requirements for differential pairs in PCB design, resulting in a substantial decrease in signal quality. Summary of the Invention

[0004] This application provides a method, apparatus, device, and storage medium for isochronous control of differential pairs, in order to achieve the standard of isochronous control requirements for differential pairs in PCB design and improve the signal quality of differential pairs.

[0005] In a first aspect, this application provides an isochronous control method for differential pairs, wherein the differential pairs include surface differential pairs located on the surface layer of a printed circuit board, the surface differential pairs including a first trace and a second trace, the length of the first trace being less than the length of the second trace, and the isochronous control method includes:

[0006] Obtain the initial delay difference of the differential pair;

[0007] Based on the initial time delay difference, perform at least one of the following adjustment operations to obtain a differential pair whose time delay difference meets the differential pair time-comparison control requirements:

[0008] Adjust the width of the first trace from the initial width to a first width that is greater than the initial width;

[0009] Adjust the width of the second trace from the initial width to a second width that is smaller than the initial width;

[0010] Adjust the height between the second trace and the reference layer from the initial height to the target height.

[0011] One possible implementation involves adjusting the height between the second trace and the reference layer from the initial height to the target height, including:

[0012] By hollowing out the reference layer, the height between the second routing cable and the reference layer is adjusted from the initial height to the target height.

[0013] In one possible implementation, obtaining the initial delay difference of the differential pair includes:

[0014] Obtain the initial width and initial height. The initial width of the first and second traces is the same.

[0015] Determine the initial time delay difference of the differential pair based on the initial width and initial height.

[0016] In one possible implementation, the initial delay difference of the differential pair is determined based on the initial width and initial height, including:

[0017] Obtain the copper foil thickness of the first trace and the second trace, wherein the copper foil thickness of the first trace and the second trace are the same;

[0018] An estimation model is used to estimate the comprehensive equivalent dielectric constant of the initial width, initial height and copper foil thickness, and the comprehensive equivalent dielectric constant is obtained. This estimation model is used to reflect the relationship between the initial width and initial height and the comprehensive equivalent dielectric constant.

[0019] Based on the comprehensive equivalent dielectric constant, the signal propagation rates of the first and second traces are determined;

[0020] The initial time delay difference of the differential pair is determined based on the signal propagation rate.

[0021] One possible implementation involves obtaining a differential pair whose delay difference satisfies the isochronous control requirements of the differential pair, including:

[0022] The target delay difference is determined based on the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer.

[0023] If the target delay difference meets the differential pair peer-to-peer control requirements, then a differential pair whose delay difference meets the differential pair peer-to-peer control requirements is obtained.

[0024] If the target delay difference does not meet the differential peer-to-peer time control requirements, the adjustment operation is repeated.

[0025] In one possible implementation, the target delay difference is determined based on the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer, including:

[0026] The simulation model is used to simulate the time delay difference of the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer, so as to obtain the target time delay difference.

[0027] In one possible implementation, the isochronous control method for difference pairs also includes:

[0028] If the time delay difference obtained by performing the adjustment operation does not meet the differential peer-to-peer time control requirements, then the target length of the first trace is determined based on the obtained time delay difference.

[0029] Adjust the length of the first trace to the target length.

[0030] Secondly, this application provides an isochronous control device for a differential pair, wherein the differential pair includes a surface differential pair located on the surface layer of a printed circuit board, the surface differential pair including a first trace and a second trace, the length of the first trace being less than the length of the second trace, and the isochronous control device includes:

[0031] The acquisition module is used to obtain the initial delay difference of the differential pair;

[0032] The adjustment module is configured to perform at least one of the following adjustment operations based on the initial time delay difference, so as to obtain a differential pair whose time delay difference meets the differential pair time-of-flight control requirements:

[0033] Adjust the width of the first trace from the initial width to a first width that is greater than the initial width;

[0034] Adjust the width of the second trace from the initial width to a second width that is smaller than the initial width;

[0035] Adjust the height between the second trace and the reference layer from the initial height to the target height.

[0036] In one possible implementation, the adjustment module is specifically used for:

[0037] By hollowing out the reference layer, the height between the second routing cable and the reference layer is adjusted from the initial height to the target height.

[0038] In one possible implementation, the acquisition module is specifically used for:

[0039] Obtain the initial width and initial height. The initial width of the first and second traces is the same.

[0040] Determine the initial time delay difference of the differential pair based on the initial width and initial height.

[0041] In one possible implementation, the acquisition module can also be used for:

[0042] Obtain the copper foil thickness of the first trace and the second trace, wherein the copper foil thickness of the first trace and the second trace are the same;

[0043] An estimation model is used to estimate the comprehensive equivalent dielectric constant of the initial width, initial height and copper foil thickness, and the comprehensive equivalent dielectric constant is obtained. This estimation model is used to reflect the relationship between the initial width and initial height and the comprehensive equivalent dielectric constant.

[0044] Based on the comprehensive equivalent dielectric constant, the signal propagation rates of the first and second traces are determined;

[0045] The initial time delay difference of the differential pair is determined based on the signal propagation rate.

[0046] In one possible implementation, the adjustment module can also be used for:

[0047] The target delay difference is determined based on the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer.

[0048] If the target delay difference meets the differential pair peer-to-peer control requirements, then a differential pair whose delay difference meets the differential pair peer-to-peer control requirements is obtained.

[0049] If the target delay difference does not meet the differential peer-to-peer time control requirements, the adjustment operation is repeated.

[0050] In one possible implementation, the adjustment module can also be used for:

[0051] The simulation model is used to simulate the time delay difference of the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer, so as to obtain the target time delay difference.

[0052] In one possible implementation, the isochronous control device for the difference pair further includes a determining module, which is used for:

[0053] If the time delay difference obtained by performing the adjustment operation does not meet the differential peer-to-peer time control requirements, then the target length of the first trace is determined based on the obtained time delay difference.

[0054] Adjust the length of the first trace to the target length.

[0055] Thirdly, this application provides an electronic device, comprising:

[0056] At least one processor;

[0057] and memory connected to at least one processor;

[0058] The memory is used to store computer execution instructions, which are executed by at least one processor to enable the at least one processor to perform the method provided in the first aspect.

[0059] Fourthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed, are used to implement the method provided in the first aspect.

[0060] Fifthly, this application provides a program product comprising computer-executable instructions. When the computer-executable instructions are executed, they implement the method provided in the first aspect.

[0061] This application provides a differential pair isochronous control method, apparatus, device, and storage medium. By obtaining the initial delay difference of the differential pair located on the PCB surface, and further adjusting the width of at least one of the first and second traces in the differential pair, and / or the height between the second trace and the reference layer, based on the initial delay difference, a differential pair whose delay difference meets the differential pair isochronous control requirements is obtained, thereby improving the signal quality of the differential pair. Attached Figure Description

[0062] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0063] Figure 1 A schematic diagram of the differential-time control provided for existing technologies;

[0064] Figure 2 A schematic diagram illustrating the application scenarios provided in the embodiments of this application;

[0065] Figure 3 A flowchart illustrating an isochronous control method for differential pairs provided in an embodiment of this application;

[0066] Figure 4 A flowchart of an isochronous control method for differential pairs provided in another embodiment of this application;

[0067] Figure 5 A flowchart of an isochronous control method for differential pairs provided in another embodiment of this application;

[0068] Figure 6a This is a schematic diagram of the structure of the initial routing of the differential pair provided in an embodiment of this application;

[0069] Figure 6b This is a schematic diagram of the structure after the differential pair routing is adjusted, provided in an embodiment of this application.

[0070] Figure 6c This is a schematic diagram of the structure of the simulation results of the initial time delay difference of the differential pair provided in the embodiments of this application;

[0071] Figure 6dA schematic diagram of the simulation results of the time delay difference after differential pair routing adjustment provided in an embodiment of this application;

[0072] Figure 7 This is a schematic diagram of the differential pair time-of-flight control device provided in an embodiment of this application;

[0073] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0074] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0075] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0076] In large-scale, high-density PCB design, isochronous control of high-speed differential pairs is crucial. Design standards typically require delay differences to be controlled within 0.8ps-1ps, with smaller individual line delay differences being preferable. However, in actual PCB design, delay differences between two lines in a differential pair may exceed the isochronous control requirements. Therefore, engineers need to optimize the differential pair routing to address this issue. One related technique involves layering the differential pair lines in a serpentine fashion on the inner layers of the PCB to alter the absolute length of each line, thereby changing the signal transmission delay and achieving isochronous control. However, this method only constrains the line length. Due to the influence of the transmission medium, the propagation speed of signals on the inner and outer layers differs, meaning that matching the absolute length of the differential pair traces cannot guarantee isochronous signal delay control. Furthermore, as... Figure 1 As shown in the figure, the black dashed box 11 represents the routing method of the inner layer traces. It can be seen from the figure that the inner layer differential pairs are routed using a serpentine routing method. This method changes the width of the traces in the differential pairs, leading to severe impedance mismatch and worsening crosstalk, affecting signal integrity and significantly degrading signal quality. Furthermore, from... Figure 1As can be seen, the serpentine routing method will occupy a lot of PCB routing space and interfere with surrounding vias and traces. On high-density and complex PCBs, space is generally small, and the serpentine routing method will waste valuable routing space. At the same time, it will increase the routing difficulty for layout engineers and increase the development cost.

[0077] To address the aforementioned issues, this application embodiment alters the signal propagation rate by changing the width of individual lines in the surface differential pair and the distance between the individual lines and the reference layer, thereby controlling the signal propagation delay and achieving isochronous compensation for the differential pair. The isochronous control method provided in this application embodiment does not require serpentine routing of the inner differential pair; therefore, while ensuring the differential pair meets the isochronous control requirements, it also significantly improves the signal integrity of the inner differential pair and guarantees its signal quality.

[0078] To facilitate understanding, the application scenarios of this application will be introduced first.

[0079] Figure 2 This is a schematic diagram illustrating an application scenario provided in an embodiment of this application. For example... Figure 2 As shown, the differential pair traces in the PCB include differential pair surface layer traces 21 and differential pair inner layer traces 22. Both the inner layer traces and the surface layer traces consist of two single lines. It can be understood that the inner layer traces are located on the middle layer of the PCB, and the surface layer traces are located on the surface layer of the PCB.

[0080] As shown in the figure, the inner layer traces have corners, which causes delay differences between individual lines in the differential pair. The delay differences mentioned in this embodiment refer to the delay differences between individual lines in the differential pair, where the length of a single line includes both the length of the inner layer trace and the length of the surface layer trace.

[0081] Figure 3 This is a flowchart illustrating an isochronous control method for differential pairs provided in an embodiment of this application. Figure 3 As shown, the isochronous control method for this difference pair includes the following steps:

[0082] S301, obtain the initial delay difference of the differential pair.

[0083] Optionally, the differential pair includes a surface differential pair located on the surface of the printed circuit board. Specifically, the surface differential pair includes a first trace and a second trace, wherein the length of the first trace is less than the length of the second trace.

[0084] The first and second traces of a differential pair can be called differential lines or differential pair routing. Differential pair routing is a technique that requires creating a transmission system on a PCB that balances differential signals (equal and inverted signals). Differential lines are generally connected to external differential signal systems, which use twisted-pair cables for signal transmission. One signal line in the twisted pair transmits the original signal, and the other transmits the signal inversely. Differential signals are a method used to address the lack of a good ground connection between the signal source and the load, and they inherently suppress interference in electronic products. Differential signals, also known as differential signals, use two identical signals with opposite polarities to represent a single data path. To ensure complete consistency between the two signals, the differential lines must be kept parallel, with consistent line width and spacing. Parallelism can occur on the same routing layer or between adjacent layers, with the spacing determined by the differential impedance.

[0085] The initial delay difference of the differential pair is the difference between the delay of the first trace and the delay of the second trace in the differential pair.

[0086] S302, based on the initial time delay difference, perform at least one of the following adjustment operations to obtain a differential pair whose time delay difference meets the differential pair time-of-flight control requirements:

[0087] The width of the first trace is adjusted from the initial width to a first width greater than the initial width; the width of the second trace is adjusted from the initial width to a second width less than the initial width; the height between the second trace and the reference layer is adjusted from the initial height to the target height.

[0088] A PCB is a multilayer printed circuit board. Once the stack-up structure of the PCB is determined during PCB design, the minimum distance between the differential pair surface trace and the reference plane is also fixed and cannot be changed. Therefore, the height between the second trace and the reference layer can only be adjusted by changing the spacing between the second trace and the adjacent layer. For example, the reference layer can be the grounding terminal of a wire. In some embodiments, adjusting the height between the second trace and the reference layer can be done by hollowing out the reference layer, adjusting the height between the second trace and the reference layer from the initial height to the target height. It is understood that the reference layer can be a copper foil layer; that is, the height between the second trace and the reference layer is changed by hollowing out the copper foil layer.

[0089] Based on the initial delay difference, an adjustment operation is performed to obtain a differential pair whose delay difference meets the differential pair equivalence control requirements. In one possible implementation, only one of the above is adjusted: keeping the width of the second trace and the height between the second trace and the reference layer unchanged, and adjusting the width of the first trace from the initial width to the first width; or keeping the width of the first trace and the height between the second trace and the reference layer unchanged, and adjusting the width of the second trace from the initial width to the second width; or keeping the width of the first trace and the width of the second trace unchanged, and adjusting the height between the second trace and the reference layer from the initial height to the target height, so as to obtain a differential pair whose delay difference meets the differential pair equivalence control requirements.

[0090] In another possible implementation, any two of the above can be adjusted simultaneously: keeping the width of the second trace constant, adjusting the height between the second trace and the reference layer from the initial height to the target height, and adjusting the width of the first trace from the initial width to the first width; or keeping the width of the first trace constant, adjusting the height between the second trace and the reference layer from the initial height to the target height, and adjusting the width of the second trace from the initial width to the second width; or keeping the height between the second trace and the reference layer constant, adjusting the width of the first trace from the initial width to the first width, and adjusting the width of the second trace from the initial width to the second width, so as to obtain a differential pair whose delay difference meets the differential pair equivalence control requirements.

[0091] In another possible implementation, the above three items can be adjusted simultaneously: the height between the second trace and the reference layer can be adjusted from the initial height to the target height, the width of the first trace can be adjusted from the initial width to the first width, and the width of the second trace can be adjusted from the initial width to the second width, so as to obtain a differential pair whose delay difference meets the differential pair equivalence control requirements.

[0092] Specifically, when adjusting the width of the first trace, the width of the first trace needs to be increased based on the initial width; when adjusting the width of the second trace, the width of the second trace needs to be decreased based on the initial width.

[0093] In this embodiment, the initial delay difference of the differential pair located on the PCB surface is obtained; and based on this initial delay difference, the following operations are performed: adjusting the width of the first trace from the initial width to the first width, and / or adjusting the width of the second trace from the initial width to the second width, and / or adjusting the height between the second trace and the reference layer from the initial height to the target height. At least one of these adjustments is performed to obtain a differential pair whose delay difference meets the isochronous control requirements. This method achieves isochronous control of the differential pair by adjusting the shape (width) and distance of the single trace from the reference layer of the differential pair on the PCB surface, while ensuring the integrity of the signals in the inner layers of the PCB and improving the signal quality of the differential pair.

[0094] Figure 4 This is a flowchart of an isochronous control method for differential pairs provided in another embodiment of this application. This embodiment is a detailed description of step S301 in the previous embodiment. Figure 4 As shown, obtaining the initial time delay difference of the differential pair may specifically include the following steps:

[0095] S401, obtain the initial width and initial height.

[0096] Optionally, the first and second traces have the same initial width. The initial height is the initial distance between the second trace and the reference layer.

[0097] S402, determine the initial time delay difference of the differential pair based on the initial width and initial height.

[0098] In some embodiments, determining the initial delay difference of the differential pair based on the initial width and initial height may include the following steps:

[0099] S4021, obtain the copper foil thickness of the first and second traces.

[0100] Optionally, the copper foil thickness of the first trace and the second trace is the same.

[0101] S4022 uses an estimation model to estimate the comprehensive equivalent dielectric constant of the initial width, initial height, and copper foil thickness, and obtains the comprehensive equivalent dielectric constant.

[0102] Optionally, the estimation model is used to reflect the relationship between the initial width and initial height relative to the overall equivalent dielectric constant. For example, the estimation model can be expressed by the following formula:

[0103]

[0104] Where ε is the comprehensive equivalent dielectric constant, εr is the relative dielectric constant of the PCB material (the relative dielectric constant of air is 1.006), W represents the initial width, H represents the initial height, and M represents the copper foil thickness of the first and second traces. F is a variable related to the initial width and initial height. Specifically, the relationship between F and the initial width and initial height can be expressed by the following formula:

[0105]

[0106]

[0107] As can be seen from the above formula, the value of F varies when the ratio of the initial width to the initial height is different.

[0108] It should be noted that the comprehensive equivalent dielectric constant is used to represent the comprehensive equivalent dielectric constant between the PCB and air and the solder mask.

[0109] S4023, based on the comprehensive equivalent dielectric constant, determine the signal propagation rate of the first and second traces.

[0110] It is understandable that signal transmission in PCB surface differential pair traces occurs within a medium corresponding to the comprehensive equivalent dielectric constant. Therefore, the magnitude of the comprehensive equivalent dielectric constant affects the signal propagation rate of the PCB surface differential pair traces. Optionally, the relationship between the comprehensive equivalent dielectric constant and the signal propagation rate of the PCB surface differential pair traces can be expressed by the following formula:

[0111]

[0112] Where V represents the signal propagation speed. As can be seen from the above formula, the magnitude of the signal propagation speed is negatively correlated with the overall equivalent dielectric constant.

[0113] S4024, determine the initial time delay difference of the differential pair based on the signal propagation rate.

[0114] It is understandable that the length of a single line in a differential pair is determined by the distance between the two chips to be connected and the actual routing requirements in the PCB.

[0115] Optionally, the length of the differential pair trace is obtained, and the ratio of the trace length to the signal propagation speed is used as the time delay of the differential pair trace. For example, the length of the first trace in the differential pair is less than the length of the second trace. The time delay can be expressed by the following formula:

[0116] T = L / V

[0117] Where T represents the time delay and L represents the length of the trace.

[0118] Specifically, the delay of the first trace and the second trace are calculated separately, and the difference between the delay of the first trace and the delay of the second trace is used as the initial delay difference.

[0119] In this embodiment, by obtaining the initial width and initial height, and determining the initial delay difference of the differential pair based on the initial width and initial height, this method obtains the initial delay difference and further adjusts the delay difference of the first and second traces of the differential pair based on the initial delay difference, so as to obtain a differential pair whose delay difference meets the isochronous control requirements of the differential pair.

[0120] Figure 5This is a flowchart of an isochronous control method for differential pairs provided in another embodiment of this application. This embodiment provides a detailed description of the step in the above embodiment: obtaining a differential pair whose delay difference satisfies the isochronous control requirements. Specifically, obtaining a differential pair whose delay difference satisfies the isochronous control requirements may include the following steps:

[0121] S501, determine the target delay difference based on the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer.

[0122] It is understandable that, depending on the adjustment method, the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer can be different from the initial width and initial height, or they can be the same as the initial width and initial height.

[0123] In some embodiments, a simulation model can be used to simulate the time delay difference between the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer, to obtain the target time delay difference. For example, this simulation model can be an HFSS 3D simulation model.

[0124] It should be noted that the accuracy of the time delay difference obtained through the estimation model is lower than that obtained through the simulation model. Optionally, the initial time delay difference can also be obtained through simulation processing using a simulation model.

[0125] S502, determine whether the target time delay difference meets the differential peer-to-peer time control requirements.

[0126] Determine whether the target time delay difference meets the differential peer-to-peer time control requirements. If it does, proceed to step S503; otherwise, proceed to step S504.

[0127] Optionally, the differential peer-to-peer time control requirement can be that the delay difference is less than a preset threshold. When the target delay difference is less than the preset threshold, it means that the target delay difference meets the differential peer-to-peer time control requirement; when the target delay difference is greater than or equal to the preset threshold, it means that the target delay difference does not meet the differential peer-to-peer time control requirement. For example, the preset threshold can be 1 ps.

[0128] S503, obtain the differential pair whose time delay difference meets the differential pair isochronous control requirements.

[0129] S504, Repeat the adjustment operation.

[0130] Optionally, the adjustment operation is repeated until a differential pair is obtained that meets the control requirements for differential pair equivalence. Specifically, the adjustment operation is similar to that described in the above embodiments, and will not be repeated here.

[0131] It is understandable that there are limitations on the adjustment range of the width of the first and second traces of the differential pair, as well as the height between the second trace and the reference layer. When performing the above adjustment operations and adjusting all adjustment parameters to their limits, if a differential pair with a time delay difference that meets the differential pair equivalence control requirements still cannot be obtained, other adjustment methods are required. In one possible implementation, if the time delay difference obtained by performing the adjustment operations does not meet the differential pair equivalence control requirements, then the target length of the first trace is determined based on the obtained time delay difference; the length of the first trace is adjusted to the target length. Optionally, the adjustment method for the length of the first trace can be to increase the length of the first trace. Specifically, the amount of increase in the trace length is determined by the time delay difference obtained based on the above adjustment operations. For example, if the delay difference required by the isochronous control is less than 1ps, and the delay difference obtained by performing the adjustment operation as described above is 1.3ps, then the length of the first trace needs to be appropriately increased to compensate for the delay T = 0.3ps, so that the delay difference within the differential pair meets the isochronous control requirements, thereby obtaining a differential pair whose delay difference meets the isochronous control requirements of the differential pair.

[0132] In this embodiment, the target delay difference is determined based on the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer. Further, the differential pair whose delay difference meets the differential pair time-to-time control requirements is determined by judging whether the target delay difference meets these requirements. This method, by adjusting the trace width of the surface layer differential pair and the height between a single line in the differential pair and the reference layer, ensures that the obtained differential pair meets the differential pair time-to-time control requirements while also improving the signal quality of the differential pair and guaranteeing the integrity of the inner layer differential pair signal.

[0133] In summary, the technical effects of the differential pair isochronous control method provided in the embodiments of this application will be described in detail below with reference to the figures.

[0134] Figure 6a This is a schematic diagram of the initial routing structure of the differential pair provided in an embodiment of this application. Figure 6b This is a schematic diagram of the structure after the differential pair routing is adjusted, provided in an embodiment of this application. Figure 6c This is a schematic diagram of the structure of the simulation results of the initial time delay difference of the differential pair provided in the embodiments of this application. Figure 6d This is a schematic diagram illustrating the simulation results of the time delay difference after differential pair routing adjustment provided in an embodiment of this application. Figure 6a It can be seen from this that the initial widths of the first trace 61 and the second trace 62 in the initial routing of the differential pair are the same. Figure 6b As can be seen, after the differential pair routing adjustment, the widths of the first trace 61 and the second trace 62 are no longer the same. Figure 6a and Figure 6bIt can be seen that after the width of the first trace 61 is adjusted, it is larger than the width of the first trace in the initial surface trace 21, and after the width of the second trace 62 is adjusted, it is smaller than the width of the second trace in the initial surface trace 21. Figure 6b The height between the second trace 62 of the surface differential pair and the reference layer was also adjusted (not shown), increasing the height between the second trace 62 and the reference layer. No adjustments were made to the inner differential pairs. Figure 6c As can be seen, the initial time delay difference is 3.325 ps, which is far from meeting the 1 ps requirement of differential peer-to-peer timing control. After adjustment using the differential peer-to-peer timing control method provided in this application embodiment, from Figure 6d As can be seen, the adjusted delay difference is 0.865ps, which meets the isochronous control requirements of the differential pair.

[0135] Figure 7 This is a schematic diagram of the isochronous control device for differential pairs provided in an embodiment of this application. The isochronous control device 70 for differential pairs provided in this embodiment includes: an acquisition module 710 and an adjustment module 720.

[0136] The acquisition module 710 is used to acquire the initial delay difference of the differential pair; the adjustment module 720 is used to perform at least one of the following adjustment operations based on the initial delay difference to obtain a differential pair whose delay difference meets the isochronous control requirements of the differential pair: adjusting the width of the first trace from the initial width to a first width greater than the initial width; adjusting the width of the second trace from the initial width to a second width less than the initial width; and adjusting the height between the second trace and the reference layer from the initial height to the target height.

[0137] In one possible implementation, the adjustment module 720 is specifically used to: adjust the height between the second trace and the reference layer from the initial height to the target height by hollowing out the reference layer.

[0138] In one possible implementation, the acquisition module 710 is specifically used to: acquire the initial width and initial height, wherein the initial widths of the first trace and the second trace are the same; and determine the initial delay difference of the differential pair based on the initial width and initial height.

[0139] In one possible implementation, the acquisition module 710 can also be used to: acquire the copper foil thickness of the first trace and the second trace, wherein the copper foil thickness of the first trace and the second trace is the same; use an estimation model to estimate the comprehensive equivalent dielectric constant of the initial width, initial height and copper foil thickness to obtain the comprehensive equivalent dielectric constant, wherein the estimation model is used to reflect the relationship between the initial width and initial height and the comprehensive equivalent dielectric constant; determine the signal propagation rate of the first trace and the second trace based on the comprehensive equivalent dielectric constant; and determine the initial time delay difference of the differential pair based on the signal propagation rate.

[0140] In one possible implementation, the adjustment module 720 can also be used to: determine the target delay difference based on the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer; if the target delay difference meets the differential peer-to-peer timing control requirements, then a differential pair whose delay difference meets the differential peer-to-peer timing control requirements is obtained; if the target delay difference does not meet the differential peer-to-peer timing control requirements, then the adjustment operation is repeated.

[0141] In one possible implementation, the adjustment module 720 can also be used to: use a simulation model to simulate the time delay difference of the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer, and obtain the target time delay difference.

[0142] In one possible implementation, the isochronous control device for the differential pair further includes a determining module (not shown), which is used to: if the time delay difference obtained by performing the adjustment operation does not meet the isochronous control requirements of the differential pair, determine the target length of the first trace based on the obtained time delay difference; and adjust the length of the first trace to the target length.

[0143] The apparatus provided in this embodiment can be used to execute the method steps of the above method embodiments. The specific implementation and technical effects are similar, and will not be described again here.

[0144] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 8 As shown, the electronic device 80 includes:

[0145] At least one processor 801; and

[0146] A memory 802 is communicatively connected to at least one processor 801; wherein,

[0147] The memory 802 stores instructions that can be executed by at least one processor 801, which enables the at least one processor 801 to perform the method steps described above.

[0148] The specific implementation process of processor 801 can be found in the above method embodiments. The specific implementation method and technical effect are similar, and will not be repeated here.

[0149] This application provides a computer-readable storage medium storing computer-executable instructions. When executed by a processor, the computer-executable instructions are used to implement the method steps as described in the above method embodiments. The specific implementation methods and technical effects are similar and will not be repeated here.

[0150] This application also provides a program product comprising computer-executable instructions. When the computer-executable instructions are executed, they implement the method steps as described in the above method embodiments. The specific implementation and technical effects are similar and will not be repeated here.

[0151] Other embodiments of the application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not claimed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0152] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for isochronous control of differential pairs, characterized in that, The differential pair includes a surface differential pair located on the surface layer of the printed circuit board. The surface differential pair includes a first trace and a second trace, wherein the length of the first trace is less than the length of the second trace. The isochronous control method includes: Obtain the initial width and initial height, where the initial widths of the first trace and the second trace are the same; Obtain the copper foil thickness of the first trace and the second trace, wherein the copper foil thickness of the first trace and the second trace are the same; An estimation model is used to estimate the comprehensive equivalent dielectric constant of the initial width, the initial height, and the copper foil thickness to obtain the comprehensive equivalent dielectric constant. The estimation model is used to reflect the relationship between the initial width and the initial height and the comprehensive equivalent dielectric constant. The signal propagation rates of the first trace and the second trace are determined based on the comprehensive equivalent dielectric constant. The initial time delay difference of the differential pair is determined based on the signal propagation rate. Based on the initial time delay difference, perform at least one of the following adjustment operations to obtain a differential pair whose time delay difference satisfies the differential pair isochronous control requirements: The width of the first trace is adjusted from the initial width to a first width, wherein the first width is greater than the initial width; The width of the second trace is adjusted from the initial width to a second width, where the second width is smaller than the initial width. Adjust the height between the second trace and the reference layer from the initial height to the target height.

2. The method according to claim 1, characterized in that, Adjusting the height between the second trace and the reference layer from the initial height to the target height includes: By hollowing out the reference layer, the height between the second trace and the reference layer is adjusted from the initial height to the target height.

3. The method according to any one of claims 1 to 2, characterized in that, The differential pair whose time delay difference satisfies the isochronous control requirements includes: The target delay difference is determined based on the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer. If the target time delay difference meets the differential pair peer-to-peer control requirements, then a differential pair whose time delay difference meets the differential pair peer-to-peer control requirements is obtained; If the target delay difference does not meet the differential peer-to-peer time control requirements, the adjustment operation is repeated.

4. The method according to claim 3, characterized in that, The step of determining the target delay difference based on the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer includes: The target delay difference is obtained by simulating the time delay difference between the adjusted width of the first trace, the width of the second trace, and the height between the second trace and the reference layer using a simulation model.

5. The method according to any one of claims 1 to 2, characterized in that, Also includes: If the time delay difference obtained by performing the adjustment operation does not meet the differential peer-to-peer time control requirements, then the target length of the first trace is determined based on the obtained time delay difference. Adjust the length of the first trace to the target length.

6. An isochronous control device for differential pairs, characterized in that, The differential pair includes a surface differential pair located on the surface layer of the printed circuit board. The surface differential pair includes a first trace and a second trace, wherein the length of the first trace is less than the length of the second trace. The isochronous control device includes: An acquisition module is used to acquire the initial width and initial height, wherein the initial widths of the first trace and the second trace are the same; acquire the copper foil thickness of the first trace and the second trace, wherein the copper foil thicknesses of the first trace and the second trace are the same; perform comprehensive equivalent dielectric constant estimation on the initial width, the initial height, and the copper foil thickness using an estimation model to obtain a comprehensive equivalent dielectric constant, wherein the estimation model is used to reflect the relationship between the initial width and the initial height and the comprehensive equivalent dielectric constant; determine the signal propagation rate of the first trace and the second trace based on the comprehensive equivalent dielectric constant; and determine the initial time delay difference of the differential pair based on the signal propagation rate. The adjustment module is configured to perform at least one of the following adjustment operations based on the initial time delay difference, so as to obtain a differential pair whose time delay difference meets the differential pair isochronous control requirements: The width of the first trace is adjusted from the initial width to a first width, wherein the first width is greater than the initial width; The width of the second trace is adjusted from the initial width to a second width, where the second width is smaller than the initial width. Adjust the height between the second trace and the reference layer from the initial height to the target height.

7. An electronic device, characterized in that, include: At least one processor; and a memory communicatively connected to the at least one processor; The memory is used to store instructions executable by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1 to 5.

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