How to Show All DRC in Skipper with Commands

In the world of circuit design, verification and debugging are crucial steps to ensure everything works correctly. One tool often used for this purpose is Skipper.

Skipper helps designers find and address design rule violations (DRC). In this article, we will walk you through how to show all DRC in Skipper using commands.

We will cover everything from what DRC is, why it is essential, and the step-by-step process of displaying them within Skipper using commands.

What is a DRC in Skipper?

What are Design Rule Checks (DRC)? Design Rule Checks (DRC) are automated tests that verify whether a layout follows the set rules defined by the manufacturing process.

These rules ensure that the chip layout will be manufacturable and functional. DRC is a critical step in the design flow because errors in this phase could result in non-functional designs or defects in the manufacturing process.

How Does Skipper Handle DRC? Skipper is a tool used by many designers to streamline the process of design rule checking. It is capable of running DRCs, and the results help in identifying violations in the design.

Using commands in Skipper, users can view all DRCs in a design project. This feature becomes very useful, especially when managing large, complex designs where manual checks would be inefficient.

Why Should You Run All DRC in Skipper?

Importance of DRC for Circuit Design Design Rule Checks play an essential role in the successful completion of circuit designs.

They ensure that the layout complies with the manufacturer’s guidelines and constraints. Violations might include issues like two metal wires being too close, insufficient layer spacing, or incorrect via placements.

Impact of Not Running All DRCs Failure to run all DRC checks could result in errors slipping through to the final design.

This would mean costly revisions and even the risk of producing faulty hardware. Skipper’s DRC commands allow you to identify these violations early in the design phase, saving time and money.

How to Show All DRC in Skipper Using Commands?

Step-by-Step Process

Opening Skipper Start by launching the Skipper tool. Open the design project you want to check. Ensure that all the required libraries and files are properly loaded, as DRC commands can only be executed when the entire design is accessible.

Enter the Command Mode To enter command mode in Skipper, use the following keystroke:
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skipper> command

Display All DRC Commands Use the command that triggers the display of all DRC violations within your design. The standard command to show all DRC is:
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skipper> show_drc_all

Filter Specific DRC Errors (Optional) If you’re only interested in specific DRC violations, you can filter the results using parameters within the command. For example, to show only spacing violations, you can use:
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skipper> show_drc_type spacing

Review the Results Once executed, Skipper will show a list of all the DRC violations. These will be displayed in the terminal or output window, depending on your Skipper setup. You can now begin to analyze and fix the issues.

How to Interpret the DRC Results in Skipper?

Understanding DRC Output The DRC output will show a list of violations, each tied to a specific design rule. For each violation, Skipper provides information such as the location of the issue, the type of rule violated, and the severity level.

Categorizing DRC Violations Not all DRC violations are equally severe. It is essential to categorize them by criticality. For example, spacing violations between critical nets might be more important than minor overlap in non-critical layers.

Command Variations for Showing All DRC in Skipper

Common Commands to Display DRC While the most commonly used command is show_drc_all, there are other variations depending on the type of design rule or the level of detail you want:

To display errors for a specific layer:
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skipper> show_drc_layer <layer_name>

To show violations for a single net:
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skipper> show_drc_net <net_name>

To only display critical errors:
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skipper> show_drc_critical

Benefits of Using Commands in Skipper Using commands instead of a graphical interface can speed up the process, particularly for large projects. Command-line operations also offer more flexibility in terms of filtering and controlling the output.

Command	Pros	Cons
show_drc_all	Shows all DRC errors quickly, providing an overview of the entire project.	Can be overwhelming for large designs with many violations.
show_drc_type	Helps filter specific types of DRC violations (e.g., spacing issues).	Requires knowledge of DRC categories for effective filtering.
show_drc_critical	Focuses on the most important errors, reducing the list size.	May miss non-critical issues that could still impact design performance.
show_drc_net	Allows pinpointing violations related to specific nets.	Time-consuming if there are many nets to check individually.

Best Practices for Running DRC in Skipper

Set Up Regular Checks Running DRCs at multiple stages of the design process helps identify problems early. Waiting until the end of the project to run all DRC checks can result in an overwhelming number of errors.

Review Violations by Type Not all violations are equally severe. Prioritize fixing critical violations such as those related to spacing, metal density, and power routing first.

Use Layers and Nets for Focused Checks Sometimes, the errors might be isolated to specific layers or nets. Skipper’s commands allow you to narrow down the focus to find errors faster and manage them more effectively.

Conclusion: How to Show All DRC in Skipper with Commands

Using Skipper’s command-line tools to show all DRC violations makes the design process faster and more efficient.

By automating the error-checking process, Skipper ensures that designers can focus on fixing issues rather than manually identifying them.

Mastering these commands will significantly improve your workflow and reduce design errors, ensuring a smooth transition from design to manufacturing.

FAQs: How to Show All DRC in Skipper with Commands

Can I export the DRC results in Skipper?

Yes, Skipper allows you to export DRC results into various formats such as CSV, making it easier to review and share with team members.

How often should I run DRC checks in Skipper?

It is a good practice to run DRC checks frequently during the design process, especially after making major design changes.

What should I do if I find too many violations?

Focus on the most critical violations first. Use Skipper’s filtering commands to categorize and prioritize errors.

Are all DRC violations critical?

No, some violations may have little impact on the overall design. It’s essential to categorize them by severity.