CN111460754B - Impedance checking method - Google Patents

Abstract

A method of impedance checking. In the wiring software, the rule name of the line segment setting rule is formulated in a predefined format, the rule name includes the target impedance value, and the line segment setting rule includes line distance information and line width information of multiple lines. Using the extraction software to read the line segment setting rules from the layout design diagram to obtain multiple lines for impedance calculation. Use the extraction software to obtain the target impedance value from the rule name, and feed the target impedance value into the simulation software. Using simulation software to calculate the impedance value of each line, and judge whether the calculated impedance value of each line is abnormal based on the target impedance value.

Description

Method of Impedance Check

technical field

The invention relates to a simulation method, and in particular to a method for impedance inspection.

Background technique

As the transmission speed of the signal becomes faster and faster, the control of impedance has been regarded as the most basic and important part. When the impedance of the layout routing of the printed circuit board (PCB) is properly controlled, the signal reflection The energy is less. And the energy loss is small, and the quality of the signal is good. Therefore, in order to produce a good quality product, impedance control is extremely important when laying out a printed circuit board.

With today's technology, most printed circuit boards will have impedance control lines, such as designing antenna lines, Universal Serial Bus (Universal Serial Bus, USB), Mobile Industry Processor Interface (Mobile Industry Processor Interface, MIPI), High Definition Multimedia Interface (HDMI), Clock (Clock), Serial Advanced Technology Attachment (Serial Advanced Technology Attachment, SATA), Fast Peripheral Component Interconnect (PCI Express, PCIe), Display Port (DisplayPort, DP) etc., all need to do impedance control.

The current process of impedance inspection in the industry is as follows. Buy the software first, and then ask the software manufacturer to train the employees. After the training, employees still need time to practice the operation, and only after they are familiar with the software high enough can they start the impedance inspection service for the company's project. However, a large amount of data still needs to be prepared before performing the inspection, for example, list the name of the line to be inspected, list each segment, and list the serial number if there is one. However, since the impedance of each line (net) requires different pass/fail criteria, the target impedance value of each line must also be listed to start the simulation and finally generate a report.

The above-mentioned traditional methods have the following problems: Only those who are familiar with the software can carry out the action of impedance inspection, and manually sorting out the line data required for impedance control not only takes a lot of time, but may even cause data omission due to human error.

Contents of the invention

The invention provides a method for impedance inspection, which integrates wiring software and simulation software in an automatic system, which can save manpower and reduce the problem of human error.

The impedance checking method of the present invention includes: in the wiring software, formulate the rule name of the line segment setting rule in a predefined format and store it in the layout design drawing, wherein the rule name includes the target impedance value, and the line segment setting rule includes Line spacing information and line width information of multiple lines; use the extraction software to read the line segment setting rules from the layout design drawing to obtain multiple lines (net) for impedance calculation; use the extraction software to self-layout the rules of the layout design drawing Obtain the target impedance value from the name, and feed the target impedance value into the simulation software; and use the simulation software to calculate the impedance value of each line, and judge whether the calculated impedance value of each line is abnormal based on the target impedance value.

In an embodiment of the present invention, formulating the rule name of the line segment setting rule in a predefined format further includes: setting the target impedance value at a specific position in the rule name based on the predefined format, and prohibiting Followed by numbers.

In an embodiment of the present invention, the specific position is one of the start position, middle position and end position of the rule name.

In an embodiment of the present invention, the impedance checking method further includes: in the wiring software, inserting lines with impedance control requirements into line segment setting rules.

In an embodiment of the present invention, in the wiring software, after the lines with impedance control requirements are included in the line segment setting rules, if it is determined that one of the lines violates the line segment setting rules, a notification message is sent.

In an embodiment of the present invention, the step of judging whether the calculated impedance value of each line is abnormal based on the target impedance value includes: setting a target impedance range based on the target impedance value; judging whether the calculated impedance value of each line exceeds the target Impedance range; if the calculated impedance value exceeds the target impedance range, it is determined that the corresponding line is abnormal; and if the calculated impedance value is within the target impedance range, it is determined that the corresponding line passes the inspection.

In one embodiment of the present invention, after judging whether the calculated impedance value of each line is abnormal based on the target impedance value, a result interface is generated, and a link is established between the result interface and the layout design drawing, so that when the selection is received through the result interface When the command is executed, the layout design diagram is displayed, and the corresponding position is marked in the layout design diagram.

Based on the above, any printed circuit board wiring software and any simulation software for calculating impedance can be successfully integrated into an automated system, thereby avoiding the problem of wasting time caused by human intervention in the process of importing simulation software.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail with reference to the accompanying drawings.

Description of drawings

FIG. 1 is a block diagram of a system architecture according to an embodiment of the invention.

FIG. 2 is a flowchart of a method for impedance inspection according to an embodiment of the invention.

FIG. 3 is a schematic diagram of a user interface of the wiring software according to an embodiment of the invention.

FIG. 4 is a schematic diagram of an interface of a wiring software according to an embodiment of the present invention.

FIG. 5A is a schematic diagram of a result interface according to an embodiment of the invention.

FIG. 5B is a schematic diagram of a layout design diagram according to an embodiment of the invention.

Explanation of reference signs:

110: Wiring software

120: Extraction software

130: Simulation software

S205, S210, S215, S220: each step of the method of impedance inspection

310, 410: Constraint rule checker

510: Results interface

511: Result Options

520: Layout design drawing

521: location

Detailed ways

FIG. 1 is a block diagram of a system architecture according to an embodiment of the invention. In this embodiment, the system architecture for implementing the method for impedance checking includes routing software 110 , extraction software 120 and simulation software 130 .

This embodiment is implemented by using an electronic device with computing capability. The electronic device includes processors, storage devices and other equipment. The storage device stores the wiring software 110 , the extraction software 120 and the simulation software 130 , and the processor drives the wiring software 110 , the extraction software 120 and the simulation software 130 to realize the impedance inspection method.

The processor can be a central processing unit (Central Processing Unit, CPU), an image processing unit (Graphic Processing Unit, GPU), a physical processing unit (Physics Processing Unit, PPU), a programmable microprocessor (Microprocessor), Embedded control chip, digital signal processor (Digital Signal Processor, DSP), application specific integrated circuit (Application Specific Integrated Circuits, ASIC) or other similar devices. The storage device is any form of fixed or removable random access memory (Random Access Memory, RAM), read-only memory (Read-Only Memory, ROM), flash memory (Flash memory), secure digital card ( Secure Digital Memory Card (SD), hard disk or other similar devices or a combination of these devices.

FIG. 2 is a flowchart of a method for impedance inspection according to an embodiment of the invention. Please refer to FIG. 1 and FIG. 2 at the same time. In step S205, in the wiring software 110, the rule name of the line segment setting rule is formulated in a predefined format and the line segment setting rule is stored in the layout design drawing (board file). For example, use a constraint rule checker to set rule names for line segments according to a predefined format. The line segment setting rule can limit the line distance information and line width information of multiple lines. Here, the predefined format is used to limit the target impedance value to be included in the rule name. In one embodiment, the routing software 110 sets the target impedance value at a specific position in the rule name based on a predefined format, and forbids numbers to follow the target impedance value, so as to prevent the extraction software 120 from identifying errors. The specific position is one of the start position, middle position and end position of the rule name. For example, taking the target impedance value of 85 ohms as an example, the rule name "85ohm_PCIE" conforms to the predefined format, but the rule name "852_PCIE" does not conform to the predefined format.

FIG. 3 is a schematic diagram of a constraint rule checker of routing software according to an embodiment of the invention. Referring to FIG. 3 , the constraint rule checker 310 includes a plurality of line segment setting rules (eg, PCS) and rule names corresponding to each line segment setting rule, and target impedance values are input in the initial positions of these rule names. For example, the target impedance value of the rule name "83OHM_[B]4=" is 83 ohms, and there is no number following the target impedance value "83". In addition, the target impedance value of the rule name "85OHM_[A]3=" is 85 ohms.

In other embodiments, it can be set to start inputting the target impedance value at the middle position of, for example, the 4th character of the rule name, or it can be set to start inputting the target impedance value at the end position of the rule name.

When performing wiring, in the wiring software 110 , the lines with impedance control requirements are included in the line segment setting rules. After the line is nested into the line segment setting rules, if it violates the nested line segment setting rules, a notification message is sent. For example, the constraint rule checker can be used to modify and verify whether the layout conforms to the line segment setting rules, and when the line does not comply with the line segment setting rules, a notification message is displayed.

After the layout design diagram is completed by the wiring software 110 , relevant information can be obtained from the layout design diagram by the extraction software 120 . That is, in step S210 , the extraction software 120 is used to obtain a plurality of lines for impedance calculation from the layout plan. Moreover, in step S215 , the extraction software 120 is used to obtain the target impedance value from the rule name of the layout design diagram, and the target impedance value is fed into the simulation software 130 .

FIG. 4 is a schematic diagram of an interface of a wiring software according to an embodiment of the present invention. In the constraint rule checker 410 in FIG. 4 , take the rule name "50OHM(4|5)(175)" as an example, expand the column of the rule name "50OHM(4|5)(175)" to view this line Multiple lines A covered by segment setting rules (eg, NCIs). Accordingly, after reading the rule name “50OHM(4|5)(175)” of the line segment setting rule, the extraction software 120 can obtain a plurality of lines A to which the line segment setting rule is applied. Moreover, based on the name of the rule, it can be known that the target impedance value of the line segment setting rule is 50 ohms. By analogy, the extraction software 120 can obtain the lines included in each line segment setting rule and the corresponding target impedance value, and feed these lines and the corresponding target impedance value to the simulation software 130 .

After that, in step S220, the simulation software 130 is used to calculate the impedance value of each line, and it is judged based on the target impedance value whether the calculated impedance value of each line is abnormal.

Specifically, the simulation software 130 sets the target impedance range based on the target impedance value corresponding to each line. For example, assuming that the target impedance value is 50 ohms, the target impedance range is set to be within plus or minus 10% of 50 ohms. However, this is only for illustration and not limited thereto. Next, the simulation software 130 calculates the impedance value of each line according to the layout design drawing, and judges whether the calculated impedance value of each line exceeds its corresponding target impedance range. If the calculated impedance value exceeds its corresponding target impedance range, it is determined that the corresponding line is abnormal. On the contrary, if the calculated impedance value is within the corresponding target impedance range, it is determined that the corresponding line passes the inspection.

And after judging whether the calculated impedance values of each line are abnormal based on the target impedance value, the simulation software 130 can generate a result interface, and establish a link between the result interface and the layout design drawing, so that when a selection command is received through the result interface, it will be displayed. Layout design drawing, and mark the corresponding position in the layout design drawing.

FIG. 5A is a schematic diagram of a result interface according to an embodiment of the invention. FIG. 5B is a schematic diagram of a layout design diagram according to an embodiment of the invention. Referring to FIG. 5A and FIG. 5B , after the result interface 510 is generated, the result interface 510 is linked with the layout design diagram 520 . In order to switch to the corresponding position in the layout design diagram 520 when a selection instruction is received through the result interface 510 . Taking the result option 511 of FIG. 5A as an example, when a selection instruction is received through the result option 511 of the result interface 510 , the layout design diagram 520 of FIG. 5B is displayed, and the corresponding position 521 is marked in the layout design diagram 520 .

In summary, the above embodiments are applicable to any wiring software and any simulation software for simulating impedance calculation. Establish a predefined format to formulate the rule name, so that the rule name is meaningful, so that the developed extraction software can recognize the rule name and extract data effectively. Moreover, since the data is extracted from the layout design drawing, any circuit name with impedance control will be extracted, thereby greatly reducing errors (such as filling in wrong names) or omissions during manual filling. In addition, the above-mentioned embodiments do not involve or limit any manner of how to calculate the impedance, so any third-party impedance calculation simulation software can be used. Through the above-mentioned embodiment, any wiring software and any simulation software can successfully complete the automation system integration, and no time will be wasted due to interruption due to human intervention in the process.

Although the present invention has been disclosed as above with the embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some changes and modifications without departing from the concept and scope of the present invention. Therefore, the present invention The scope of protection shall prevail as defined by the claims.

Claims (6)

1. A method for impedance inspection, characterized in that, comprising: In a wiring software, formulate a rule name of a line segment setting rule in a predefined format and store the line segment setting rule in a layout design diagram, the rule name includes a target impedance value, and the line segment setting rule Contains line spacing information and line width information of multiple lines; reading the line segment setting rules from the layout design drawing by using an extraction software to obtain the plurality of lines for impedance calculation; using the extraction software to obtain the target impedance value from the rule name of the layout plan, and feeding the target impedance value into a simulation software; and using the simulation software to calculate the impedance value of each of the plurality of lines, and based on the target impedance value to determine whether the calculated impedance value of each of the plurality of lines is abnormal, Wherein, the rule name for formulating the line segment setting rule in the predefined format also includes: Based on the predefined format, the target impedance value is set at a specific position in the rule name, and numbers following the target impedance value are prohibited. 2. The impedance inspection method according to claim 1, wherein the specific position is one of a start position, a middle position and an end position of the rule name. 3. The method for impedance inspection as claimed in claim 1, further comprising: In the routing software, the plurality of lines with impedance control requirements are included in the line segment setting rule. 4. The method for impedance inspection according to claim 3, characterized in that, in the wiring software, after the step of inserting the plurality of lines with impedance control requirements into the line section setting rule, further comprising: If it is determined that one of the multiple lines violates the line segment setting rule, a notification message is sent. 5. The method for impedance inspection according to claim 1, wherein the step of judging whether the calculated impedance values of each of the plurality of lines is abnormal based on the target impedance value comprises: setting a target impedance range based on the target impedance value; judging whether the calculated impedance value of each of the plurality of lines exceeds the target impedance range; If the calculated impedance value exceeds the target impedance range, it is determined that the corresponding line is abnormal; and If the calculated impedance value is within the target impedance range, it is determined that the corresponding line passes the inspection. 6. The method for impedance inspection according to claim 1, further comprising: A result interface is generated, and the result interface is linked with the layout design diagram, so that when a selection command is received through the result interface, the layout design diagram is displayed, and the corresponding position is marked in the layout design diagram.

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