Understanding the Role of config.xml in Power Topology Analysis

In the previous article, we explored how Power Topology Analysis in Allegro X System Capture helps visualize and validate power distribution networks (PDNs) directly from schematic data.

As designs grow in complexity and organizations adopt customized libraries, enabling accurate device identification becomes increasingly important. This is where the config.xml file comes into play.

What is config.xml?

The config.xml file is used by Design Integrity analyses to define how devices, pins, and properties are interpreted during analysis. It acts as a central configuration mechanism that allows the analysis engine to understand and work with company-specific library conventions.

Although Power Topology Analysis can automatically identify many common devices, every organization structures its libraries differently. Custom ref des for symbols, pin property names, and device definitions can make automatic identification more challenging. The config.xml file provides the flexibility needed to align the analysis with your library standards.

This configuration file, written in an XML format, manages various aspects of a device configuration used in the design integrity flows within System Capture. Under Cadence installation, the config.xml file contains the default values of all the parameters used in the design integrity flows. The file is available at the following location: SITE\cdssetup\sysr\config.xml

Note: Always keep a backup of the file and do not edit the original file. To edit or understand the contents of the config.xml file you can connect with ASK team at Cadence.

Why is config.xml Important for Power Topology Analysis?

Power Topology Analysis relies on correctly identifying power-related elements in the design, including:

• DC Sources
• DC-DC Converters and LDOs
• Pass-Through Devices
• Power Sinks
• Power Nets and Voltage Rails

Accurate device classification is essential for constructing a meaningful representation of power flow(Power Tree) throughout the design.

By using config.xml, organizations can customize how Power Topology Analysis recognizes these devices and interprets library information.

Example

Consider a design that uses internally developed libraries containing custom refdes for device or different pin naming conventions.

Without additional configuration, some components may require manual identification before analysis can accurately build the power topology.

By updating the config.xml file to reflect company-specific library conventions, device recognition can become more consistent across projects, reducing setup effort and improving analysis accuracy.

Benefits of Using config.xml

A well-configured config.xml can help:

• Improve automatic device identification
• Reduce manual topology setup effort
• Reuse existing library information
• Support company-specific library standards
• Improve consistency across projects and teams
• Enable more accurate topology generation

For organizations managing extensive schematic libraries, these benefits can significantly simplify the adoption and deployment of Power Topology Analysis.

When Should You Consider Updating config.xml?

You may want to review and customize the configuration when:

• Devices are not identified as expected
• Libraries use custom properties or naming conventions
• Additional identification rules are required
• Analysis setup requires frequent manual adjustments

Finally, understanding how config.xml influences Power Topology Analysis is an important step toward getting the most value from your existing libraries and design data.