Glass fiber effect induced differential signal to inside skew evaluation and optimization method and system

Abstract

The application discloses a kind of glass fiber effect causes the evaluation and optimization method and system of differential signal pair inner skew, the application includes the signal delay per unit length for the signal line simulation of various wiring angles to obtain skew-delay curve, establish basic structure skew lookup table;For the signal line segmentation of target differential signal pair, measure line length, obtain the signal delay per unit length by each segment lookup basic structure skew lookup table and multiply line length to obtain delay skew value, accumulate to obtain the maximum and minimum delay skew value of glass fiber effect caused by differential signal pair inner skew to judge whether it is up to standard, not up to standard then the signal line of target differential signal pair is executed glass fiber effect caused by differential signal pair inner skew optimization.The application aims to solve the problem that glass fiber effect causes high-speed differential signal pair inner skew glass fiber effect simulation is difficult, simulation time is long, simulation process is complex, quickly and accurately simulate the influence of glass fiber effect on differential signal skew and realize targeted optimization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of signal transmission, and particularly relates to a method and system for evaluating and optimizing skew of differential signals caused by fiber-weave effect. BACKGROUND

[0002] With the development of signal transmission technology, the transmission rate of high-speed signals is getting higher and higher, and has reached or exceeded 100 Gbps. At a higher transmission rate, the fiber-weave effect of a PCB board has a non-negligible impact on high-speed differential signals. The fiber-weave effect of a PCB board refers to a phenomenon of local change of relative permittivity caused by a structure composed of glass fiber bundles and resin in a PCB dielectric layer. This effect has a significant impact on high-speed signal transmission.

[0003] The fiber-weave effect can cause skew of differential signals. For a differential signal line, there can be a case that a line (D+) is arranged on a glass fiber bundle, and a line (D-) is arranged on a gap of the glass fiber bundle, which results in that the line (D+) has a higher effective permittivity and a lower impedance (Z0) than the line (D-). Since the signal transmission speed is inversely proportional to the square root of the dielectric constant of the medium layer, different signal delays are generated for the two differential signal lines, causing skew of the differential signals. This skew can cause an increase in common-mode voltage and a corresponding decrease in differential signals, and the generated AC common-mode effect becomes a source of crosstalk and EMI in the system. When the signal transmission rate is increased, the unit interval (UI) is rapidly reduced, and the skew ratio is getting larger and larger, which greatly affects the signal quality and even causes signal transmission errors or failures.

[0004] In view of the skew of differential signals caused by the fiber-weave effect, some methods have been proposed to alleviate and optimize the skew. In terms of design optimization, methods such as angle routing, 45-degree layout, S-shaped or Z-shaped routing, and jump routing are used to avoid parallel lines to the warp and weft fibers, so that the fiber-weave effect can be averaged, thereby alleviating the impact of the fiber-weave effect on high-speed signals. In terms of board material optimization, methods such as using flat open fiber cloth with low fiber-weave effect, selecting high-grade materials (such as glass-free materials), and rotating angle board are used to reduce the sudden change of dielectric constant to alleviate the fiber-weave effect. However, these methods significantly increase the cost and design complexity, and have certain limitations. In order to reduce the cost and design complexity, accurate evaluation is needed to achieve the use of the fiber-weave effect alleviating method with as little cost and complexity as possible.

[0005] The current glass fiber effect caused by high-speed differential signal pair skew evaluation method mainly has test and simulation. One is the evaluation method based on test, which needs to make special test board and needs to be equipped with professional high-speed signal test equipment. The cost requirement of this method is very high, and it is difficult to equip high-speed signal test equipment above 50Gbps, and the flexibility of test is not high, which greatly limits the use of test method. Two is the evaluation method based on simulation, which only needs to model and simulate the glass fiber effect, and the cost and equipment requirement is low, and it is convenient and flexible, which is a better evaluation method.

[0006] But the simulation method also has limitations. First, to accurately simulate the influence of glass fiber effect on high-speed differential signal skew, accurate modeling of PCB board material, glass fiber weaving structure, differential transmission line and other is needed. The complex model leads to the increase of simulation difficulty, and the simulation time will increase exponentially with the increase of model complexity. Secondly, there are hundreds of high-speed differential signals in a PCB board, and the situation of each pair of differential signals is different. The influence of glass fiber effect on differential signal skew is different, and it cannot be inferred from a few pairs of differential signals. But it is not realistic to simulate all differential signals because of the large amount of calculation. How to quickly and accurately simulate and evaluate the influence of glass fiber effect on differential signal skew is a problem that needs to be solved in high-speed signal design, and when the signal transmission rate reaches or exceeds 50Gbps, this problem becomes a key problem to ensure the integrity of high-speed signal. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a glass fiber effect caused by differential signal pair skew evaluation and optimization method and system, which solves the problems of large simulation difficulty, long simulation time and complex simulation process of glass fiber effect caused by high-speed differential signal pair skew, and quickly and accurately simulates and evaluates the influence of glass fiber effect on differential signal skew and realizes the targeted optimization of differential signal line.

[0008] In order to solve the above technical problems, the technical scheme adopted by the present application is:

[0009] A glass fiber effect caused by differential signal pair skew evaluation and optimization method, comprising the following steps:

[0010] S1, simulating the signal delay per unit length of signal line with various routing angles to obtain skew-delay curve;

[0011] S2, establishing a basic structure skew lookup table according to the skew-delay curve of signal line with various routing angles;

[0012] S3, segmenting and measuring the line length of the signal lines according to the signal lines of various routing angles for the signal lines of the target differential signal pair, finding the maximum delay skew value Skew max and the minimum delay skew value Skew min for the skew within the differential signal pair caused by the fiber effect according to each segment by looking up the basic structure skew lookup table.

[0013] S4, judging whether the skew within the differential signal pair caused by the fiber effect of the signal lines of the target differential signal pair meets the standard according to the maximum delay skew value Skew max and the minimum delay skew value Skew min , and if it meets the standard, ending and exiting; if it does not meet the standard, performing the skew optimization within the differential signal pair caused by the fiber effect for the signal lines of the target differential signal pair.

[0014] Optionally, the signal lines of various routing angles include signal lines of three routing angles of 0 degrees, 45 degrees and 90 degrees.

[0015] Optionally, the step S1 includes:

[0016] S1.1, establishing a 3D model for the signal lines of various routing angles in combination with the lamination structure and the signal line structure;

[0017] S1.2, simulating different skews for multiple times within a skew period, fitting the different skews and the delay obtained by simulation, thereby obtaining the skew-delay curve corresponding to the signal lines of various routing angles, wherein the x-axis in the skew-delay curve is skew and the y-axis is delay.

[0018] Optionally, the step S2 includes:

[0019] S2.1, obtaining the maximum delay skew value or the minimum delay skew value within the differential pair for the signal lines of various routing angles according to the differential pair spacing and the skew-delay curve;

[0020] S2.2, establishing a basic structure skew lookup table according to the maximum delay skew value or the minimum delay skew value within the differential pair for the signal lines of various routing angles, wherein the basic structure skew lookup table corresponds to one table entry for each routing angle of the signal lines, and the table entry includes the maximum delay skew value and the minimum delay skew value of the signal lines of the corresponding routing angle.

[0021] Optionally, the function expression of the maximum delay skew value Skew max and the minimum delay skew value Skew min for the skew within the differential signal pair caused by the fiber effect obtained by multiplying the unit length signal delay by the line length and accumulating in the step S2 is:

[0022] ,

[0023] ,

[0024] wherein len0, len45 and len90 are the line lengths of the signal lines of the three routing angles of 0 degree, 45 degree and 90 degree respectively, a, b and c are the maximum skew values of the signal lines of the three routing angles of 0 degree, 45 degree and 90 degree respectively, d, e and f are the opposite values of the minimum skew values of the signal lines of the three routing angles of 0 degree, 45 degree and 90 degree respectively.

[0025] Optionally, the step S4 comprises:

[0026] S4.1, judging whether the maximum skew value Skew max or the minimum skew value Skew min is over the standard, if the maximum skew value Skew max or the minimum skew value Skew min , then jumping to step S4.2; otherwise, ending and exiting;

[0027] S4.2, performing segmented optimization design on the signal lines of the target differential signal pair;

[0028] S4.3, reacquiring the maximum skew value Skew max or the minimum skew value Skew min of the signal lines of the target differential signal pair after the segmented optimization design, and judging whether the maximum skew value Skew max or the minimum skew value Skew min is over the standard, if the maximum skew value Skew max or the minimum skew value Skew min , then jumping to step S4.4; otherwise, ending and exiting;

[0029] S4.4, performing 45-degree layout on the signal lines of the target differential signal pair;

[0030] S4.5, reacquiring the maximum skew value Skew max or the minimum skew value Skew min of the signal lines of the target differential signal pair after the 45-degree layout, and judging whether the maximum skew value Skew max or the minimum skew value Skew min is over the standard, if the maximum skew value Skew max or the minimum skew value Skewmin If yes, then jump to step S4.6; otherwise, end and exit.

[0031] S4.6, replace the material of the signal line for the target differential signal pair with flat cloth or glass-free material, end and exit.

[0032] Optionally, the step S4.2 of performing the segmented optimization design for the signal line of the target differential signal pair comprises:

[0033] S4.2.1, facilitate to find the segment with the maximum or minimum delay skew as the current segment for the signal line of the target differential signal pair, if the traversal is successful, then jump to step S4.2.2; otherwise, jump to step S4.3.

[0034] S4.2.2, judge whether there is enough space for the design optimization for the current segment, if there is enough space for the design optimization, then jump to step S4.2.3; otherwise, jump to step S4.2.1.

[0035] S4.2.3, adopt the angle routing, S-shaped or Z-shaped routing or jump routing for the current segment, and jump to step S4.2.1.

[0036] In addition, the present application also provides a glass fiber effect caused differential signal pair internal skew evaluation and optimization system, comprising a microprocessor and a memory connected to each other, the microprocessor is programmed or configured to execute the glass fiber effect caused differential signal pair internal skew evaluation and optimization method.

[0037] In addition, the present application also provides a computer readable storage medium, the computer readable storage medium stores a computer program or instructions, the computer program or instructions are programmed or configured to execute the glass fiber effect caused differential signal pair internal skew evaluation and optimization method by the processor.

[0038] In addition, the present application also provides a computer program product, comprising a computer program or instructions, the computer program or instructions are programmed or configured to execute the glass fiber effect caused differential signal pair internal skew evaluation and optimization method by the processor.

[0039] Compared with the prior art, the present application has the following advantages: (1) the evaluation method is simple and easy to operate, and can evaluate the influence of the glass fiber effect on skew for any structure and length of the differential signal; (2) the evaluation speed is fast, for a certain PCB lamination and line width configuration, only one simulation needs to be performed at the beginning to establish a basic structure skew lookup table, and subsequent direct lookup can be performed to quickly evaluate without complex and time-consuming simulation; (3) the evaluation accuracy is high, the method is based on simulation results, has high accuracy, and fully considers the differences of different transmission line structures to reduce the evaluation error; (4) the evaluation flexibility is strong, not only the influence of the glass fiber effect on the overall skew of the differential signal can be evaluated, but also the influence on each part can be evaluated in segments, and the method has strong flexibility to provide more auxiliary information for design decision; (5) targeted design optimization, according to the evaluation results, targeted and minimized modification and optimization are performed to reduce the cost and complexity of optimization as much as possible, and the method has the advantages of simple operation, fast speed, high accuracy, and strong flexibility. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The figure is a basic flowchart of the method of the embodiment of the present application.

[0041] Figure 2 The figure is a signal line routing structure diagram of a 0-degree routing angle in the embodiment of the present application.

[0042] Figure 3 The figure is a signal line routing structure diagram of a 45-degree routing angle in the embodiment of the present application.

[0043] Figure 4 The figure is a signal line routing structure diagram of a 90-degree routing angle in the embodiment of the present application.

[0044] Figure 5 The figure is a detailed step diagram of steps S1-S3 in the embodiment of the present application.

[0045] Figure 6 The figure is a skew-delay curve diagram in the embodiment of the present application.

[0046] Figure 7 The figure is a line length diagram of the signal line of three routing angles in the embodiment of the present application.

[0047] Figure 8 The figure is a detailed step diagram of step S4 in the embodiment of the present application. DETAILED DESCRIPTION

[0048] The present application aims to solve the problems of high simulation difficulty, long simulation time and complex simulation process of the skew of high-speed differential signals caused by the glass fiber effect, quickly and accurately simulate and evaluate the influence of the glass fiber effect on the skew of differential signals, and realize the targeted optimization of differential signal lines, so that personnel in the technical field can better understand the technical solutions of the present application. The technical solutions of the present application will be further described in detail below in combination with the drawings in the embodiments of the present application.

[0049] As shown in Figure 1 , the evaluation and optimization method of the skew of differential signals caused by the glass fiber effect in the present embodiment includes the following steps:

[0050] S1, simulate the signal delay per unit length of the signal line for various routing angles to obtain a skew-delay curve;

[0051] S2, establish a basic structure skew lookup table according to the skew-delay curves of the signal lines with various routing angles;

[0052] S3, segment the signal lines of the target differential signal pair according to the signal lines with various routing angles, measure the line length, find the basic structure skew lookup table for each segment to obtain the signal delay per unit length, multiply the signal delay per unit length by the line length to obtain the delay skew value, and accumulate the delay skew values to obtain the maximum delay skew value Skew max and the minimum delay skew value Skew min of the skew of differential signals caused by the glass fiber effect;

[0053] S4, judge whether the skew of differential signals caused by the glass fiber effect of the signal lines of the target differential signal pair meets the standard according to the maximum delay skew value Skew max and the minimum delay skew value Skew min , if it meets the standard, end and exit; if it does not meet the standard, perform the optimization of the skew of differential signals caused by the glass fiber effect for the signal lines of the target differential signal pair.

[0054] In the present embodiment, the signal lines with various routing angles include signal lines with three routing angles of 0 degrees, 45 degrees and 90 degrees, Figure 2 is a schematic diagram of the routing structure of the signal line with a routing angle of 0 degrees in the present embodiment, Figure 3 is a schematic diagram of the routing structure of the signal line with a routing angle of 45 degrees in the present embodiment, Figure 4 is a schematic diagram of the routing structure of the signal line with a routing angle of 90 degrees in the present embodiment, Figures 2-4 , wherein A is resin, B is glass fiber, C is metal wire, and D is glass fiber.

[0055] Referring to Figure 5 , the step S1 in the present embodiment includes:

[0056] S1.1, a 3D model is established for the signal lines of various routing angles in combination with their stack structure and signal line structure;

[0057] S1.2, different skewing is simulated for multiple times within a skewing period, and the skewing and the delay obtained through simulation are fitted, so as to obtain skew-delay curves corresponding to the signal lines of various routing angles, as shown in the following formula: Figure 6 .

[0058] Referring to Figure 5 , the step S2 in the embodiment comprises:

[0059] S2.1, for the signal lines of various routing angles, the maximum delay skewing value or the minimum delay skewing value in the differential pair is obtained according to the differential pair spacing and the skew-delay curve; the differential pair spacing is different, and the offset is different, that is, Figures 2-4 .The offset in the formula is different. Corresponding to the delay, the delay value in the formula is different, so the delay difference (differential pair delay skewing value, skew) of the differential pair is different. Therefore, the spacing of the differential pair must be considered; it should be noted that, Figure 6 and Figures 2-4 , the offset (offset) is a concept in space, which refers to the deviation of the position; and the skew (skew) is a concept in time, which refers to the difference in time of signal transmission on the two signal lines of the differential pair; Figure 6

[0060] S2.2, the basic structure skew lookup table is established according to the maximum delay skewing value or the minimum delay skewing value in the differential pair of the signal lines of various routing angles, wherein one table entry corresponding to each routing angle of the signal line is included in the basic structure skew lookup table, and the table entry includes the maximum delay skewing value and the minimum delay skewing value of the signal line corresponding to the routing angle, as shown in Table 1.

[0061] Table 1: Basic structure skew lookup table

[0062]

[0063] Here, the signal line with small offset can be defined as D-, and the signal line with large offset can be defined as D+. The delay difference between the D+ signal and the D- signal is the delay skewing value, and a~f in Table 1 are all non-negative numbers.

[0064] In the embodiment, in the step S2, the signal delay per unit length is multiplied by the line length to obtain the delay skewing value, and the delay skewing value is accumulated to obtain the function expression of the maximum delay skewing value Skew max and the minimum delay skewing value Skew min caused by the fiber effect skewing in the differential signal pair as follows:

[0065] ,

[0066] ,

[0067] wherein len0, len45 and len90 are the line length (average length of D+ signal and D- signal, as shown in Figure 7 ) of the signal lines of the three routing angles of 0 degree, 45 degree and 90 degree respectively, a, b and c are the maximum skew values of the signal lines of the three routing angles of 0 degree, 45 degree and 90 degree respectively, d, e and f are the opposite values of the minimum skew values of the signal lines of the three routing angles of 0 degree, 45 degree and 90 degree respectively.

[0068] As shown in Figure 8 , the step S4 in the embodiment comprises:

[0069] S4.1, judging whether the maximum skew value Skew max or the minimum skew value Skew min is out of the standard, if the maximum skew value Skew max or the minimum skew value Skew min is out of the standard, then jumping to step S4.2; otherwise, ending and exiting;

[0070] S4.2, performing segmented optimization design on the signal lines of the target differential signal pair;

[0071] S4.3, reacquiring the maximum skew value Skew max or the minimum skew value Skew min of the signal lines of the target differential signal pair after the segmented optimization design, and judging whether the maximum skew value Skew max or the minimum skew value Skew min is out of the standard, if the maximum skew value Skew max or the minimum skew value Skew min is out of the standard, then jumping to step S4.4; otherwise, ending and exiting;

[0072] S4.4, performing 45-degree layout on the signal lines of the target differential signal pair;

[0073] S4.5, reacquiring the maximum skew value Skew max or the minimum skew value Skew min of the signal lines of the target differential signal pair after the 45-degree layout, and judging whether the maximum skew value Skew max or the minimum skew value Skew minwhether the maximum skew Skew or the minimum skew Skew is exceeded, if yes, jump to step S4.6; otherwise, end and exit; max or the minimum skew Skew is exceeded, if yes, jump to step S4.6; otherwise, end and exit; min

[0074] S4.6, replace the material of the signal line of the target differential signal pair with flat cloth or glass-free material (flat cloth and glass-free material have the characteristics of low glass fiber effect, which can reduce the skew caused by high-speed differential signal pairs due to glass fiber effect), end and exit.

[0075] The segmented optimization design of the signal line of the target differential signal pair in step S4.2 includes finding the segment with the maximum or minimum skew, and judging whether there is enough space for design optimization. If there is not enough space, find the second largest (or second smallest) segment of the skew, and so on. Figure 8 As shown in the figure, the segmented optimization design of the signal line of the target differential signal pair in step S4.2 of the embodiment includes:

[0076] S4.2.1, find the segment with the maximum or minimum skew as the current segment for the signal line of the target differential signal pair. If the traversal is successful, jump to step S4.2.2; otherwise, jump to step S4.3.

[0077] S4.2.2, judge whether there is enough space for design optimization in the current segment. If there is enough space for design optimization, jump to step S4.2.3; otherwise, jump to step S4.2.1.

[0078] S4.2.3, adopt angle routing, S-shaped or Z-shaped routing or jump routing for the current segment, and jump to step S4.2.1.

[0079] In summary, the evaluation and optimization method of the skew of the differential signal pair caused by the glass fiber effect can solve the problems of large simulation difficulty, long simulation time and complex simulation process of the skew of the high-speed differential signal pair caused by the glass fiber effect. It can quickly and accurately simulate and evaluate the influence of the glass fiber effect on the skew of the differential signal and realize the targeted optimization of the differential signal line, and has the advantages of simple operation, fast speed, high accuracy and strong flexibility. It should be noted that the evaluation and optimization method of the skew of the differential signal pair caused by the glass fiber effect calculates the maximum (or minimum) skew of each segment of the differential line. The result may be pessimistic, and there may be a small amount of over-design, but it can avoid the situation of optimistic evaluation but actually exceeding the design tolerance.

[0080] ​In addition, the embodiment further provides a glass fiber effect induced differential signal pair inner skew evaluation and optimization system, comprising a microprocessor and a memory connected with each other, the microprocessor is programmed or configured to execute the glass fiber effect induced differential signal pair inner skew evaluation and optimization method. The embodiment further provides a computer readable storage medium, the computer readable storage medium stores a computer program or instructions, the computer program or instructions are programmed or configured to execute the glass fiber effect induced differential signal pair inner skew evaluation and optimization method by a processor. The embodiment further provides a computer program product, comprising a computer program or instructions, the computer program or instructions are programmed or configured to execute the glass fiber effect induced differential signal pair inner skew evaluation and optimization method by a processor.

[0081] Those skilled in the art will understand that the technical solution provided by the embodiment of the present application can be in the form of a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-readable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer usable program code. The present application is described with reference to flowcharts and / or block diagrams of the method, device (system), and computer program product according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as a combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus generate a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 one or more flows and / or blocks Figure 1 one or more flows and / or blocks Figure 1 one or more flows and / or blocks Figure 1 one or more flows and / or blocks Figure 1steps of the functions specified in the one or more blocks.

[0082] The above merely describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical scheme falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that, for ordinary skilled persons in the art, some improvements and refinements without departing from the principles of the present application shall also be considered as falling within the protection scope of the present application.

Claims

1. A method for evaluating and optimizing glass fiber effect induced skew in differential signal pairs, comprising: The method comprises the following steps: S1, simulating the signal delay per unit length of signal lines with various routing angles to obtain skew-delay curves; S2, establishing a basic structure skew lookup table according to the skew-delay curves of the signal lines with various routing angles; S3, segmenting and measuring the line length according to the signal lines of various routing angles for the signal lines of the target differential signal pair, finding the unit length signal delay from the basic structure skew lookup table for each segment, multiplying the unit length signal delay by the line length to obtain the delay skew value and accumulating to obtain the maximum delay skew value Skew caused by the fiber effect skew within the differential signal pair max and the minimum delay skew value Skew min ; S4, according to the maximum skew value Skew max and the minimum skew value Skew min determining whether the skew within the target differential signal pair caused by the glass fiber effect of the signal lines of the target differential signal pair meets the standard, and if so, ending and exiting; and if not, performing skew optimization within the target differential signal pair caused by the glass fiber effect of the signal lines of the target differential signal pair. The signal lines with various routing angles include signal lines with three routing angles of 0 degrees, 45 degrees and 90 degrees; The unit length signal delay is multiplied by the line length in step S2 to obtain a delay skew value and accumulated to obtain a maximum delay skew value Skew of the differential signal pair caused by the fiber effect to the internal skew max and a minimum delay skew value Skew min The function expression is: ， ， Wherein, len0, len45 and len90 are the line lengths of the signal lines with three routing angles of 0 degrees, 45 degrees and 90 degrees respectively, a, b and c are the maximum skew delay values of the signal lines with three routing angles of 0 degrees, 45 degrees and 90 degrees respectively, and d, e and f are the opposite values of the minimum skew delay values of the signal lines with three routing angles of 0 degrees, 45 degrees and 90 degrees respectively.

2. The method of evaluating and optimizing glass fiber induced skew in differential signal pairs according to claim 1, wherein, Step S1 comprises: S1.1, establishing a 3D model for the signal lines with various routing angles in combination with their laminated structures and signal line structures; S1.2, simulating different skews for multiple times within a skew period, fitting the different skews and the delay obtained by simulation, and thus obtaining the skew-delay curves corresponding to the signal lines with various routing angles, wherein the x-axis in the skew-delay curves is skew and the y-axis is delay.

3. The method of evaluating and optimizing glass fiber induced skew in differential signal pairs according to claim 1, wherein, Step S2 comprises: S2.1, for the signal lines with various routing angles, obtaining the maximum skew delay value or the minimum skew delay value within a differential pair according to the differential pair spacing and the skew-delay curves; S2.2, establishing a basic structure skew lookup table according to the maximum skew delay value or the minimum skew delay value within the differential pair of the signal lines with various routing angles, wherein the basic structure skew lookup table has a table entry for each kind of signal line with various routing angles, and the table entry includes the maximum skew delay value and the minimum skew delay value of the corresponding signal line with various routing angles.

4. The method of fiberglass effect induced skew evaluation and optimization of a differential signal pair of claim 1, wherein, Step S4 comprises: S4.1, judge whether the maximum delay skew value Skew max or the minimum delay skew value Skew min is over the standard, if the maximum delay skew value Skew max or the minimum delay skew value Skew min is over the standard, jump to step S4.2; otherwise, end and exit. S4.2, performing segmented optimization design on the signal lines of the target differential signal pair; S4.3, reacquire the maximum delay skew value Skew of the signal line of the target differential signal pair after the segmented optimization design max or the minimum delay skew value Skew min , and determine whether the maximum delay skew value Skew of the signal line of the target differential signal pair after the segmented optimization design max or the minimum delay skew value Skew min is out of standard, if the maximum delay skew value Skew max or the minimum delay skew value Skew min is out of standard, then jump to step S4.4; otherwise, end and exit. S4.4, performing 45-degree layout on the signal lines of the target differential signal pair; S4.5, reacquire the maximum skew value Skew of the signal lines of the target differential signal pair after 45-degree layout max or the minimum skew value Skew min , and determine whether the maximum skew value Skew of the signal lines of the target differential signal pair after 45-degree layout max or the minimum skew value Skew min is out of standard, if the maximum skew value Skew max or the minimum skew value Skew min is out of standard, then jump to step S4.6; otherwise, end and exit. S4.6, replacing the board material of the signal lines of the target differential signal pair with flat cloth or glass-free material, ending and exiting.

5. The method of fiberglass effect induced skew evaluation and optimization of a differential signal pair according to claim 4, wherein, The segmented optimization design on the signal lines of the target differential signal pair in step S4.2 comprises: S4.2.1, conveniently finding the segment with the maximum or minimum skew delay of the signal lines of the target differential signal pair as the current segment, and if the traversal is successful, jumping to step S4.2.2; otherwise, jumping to step S4.3; S4.2.2, judging whether there is enough space for design optimization for the current segment, and if there is enough space for design optimization, jumping to step S4.2.3; otherwise, jumping to step S4.2.1; S4.2.3, adopting angle routing, S-shaped or Z-shaped routing or jump routing for the current segment, and jumping to step S4.2.

1.

6. A system for evaluating and optimizing glass fiber effect induced skew in differential signals, comprising a microprocessor and memory interconnected, wherein, The microprocessor is programmed or configured to perform the evaluation and optimization method of the skew in the differential signal pair caused by the glass fiber effect according to any one of claims 1-5.

7. A computer-readable storage medium having stored therein a computer program or instructions, characterized in that, The computer program or instructions are programmed or configured to perform the evaluation and optimization method of the skew in the differential signal pair caused by the glass fiber effect by the processor according to any one of claims 1-5.

8. A computer program product comprising computer programs or instructions, characterized in that, The computer program or instructions are programmed or configured to perform the method of evaluating and optimizing the bias of the differential signal caused by the glass fiber effect according to any one of claims 1-5 by the processor.

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