Virtuoso Video Diary: What Makes EM/IR Analysis A Significant Sign-Off Step?

Analyzing Electromigration (EM) and Voltage (IR) drop in IC designs while they are in the design phase should be an unmissable step. EM and IR analyses are done for each block when the layout is done and then again at the end of the design process on the IC chip. It enables the IC designer to effectively implement a robust design with minimum power integrity issues.

At advanced nodes, the IC designing has been evolving and has witnessed many changes, such as:

• Decreased metal interconnect widths, which exponentially decreases the chip cross-sectional area
• Increase in the number of wires that are susceptible to EM effects in new circuits
• Proportional scaling in the currents running through the wires, which results in extremely high current densities

So, when the size of a transistor shrinks, power management becomes more critical. Also, with IC designs becoming increasingly larger in size and more complex than before, EM rules themselves are growing in complexity! That is why EM and IR analyses have traditionally been significant checkpoints in the physical verification of transistor-level designs in analog and mixed-signal circuits. 

Benefits of EM/IR Analysis

EM effect and IR drop analyses reduce the probable power integrity issues in IC designs and enable designers to improve the IC designs early on. It also lets them run a quick sanity check to identify problems in a circuit schematic due to reasons like length and width of wires.

EM/IR Analysis in Cadence® Virtuoso® ADE Product Suite

The Cadence Voltus-Fi XL Power Integrity Solution/Spectre® Circuit Simulator EM/IR analysis in Virtuoso ADE Explorer and Virtuoso ADE Assembler is designed to provide higher capacity and better performance, as compared to any existing EM/IR solutions in the industry. Additionally, handling of complex EM rules in Virtuoso ADE makes the adaptation to newer technologies easier.

The  EM/IR solution in Virtuoso ADE has the capability to support simulators such as Spectre (for analog designs), and AMS (for mixed-signal designs) for transistor-level analysis. 

If enhanced simulation speed with golden accuracy EM/IR analysis is your requirement, you can choose to use Spectre Accelerated Parallel Simulator (APS) with both Spectre and AMS Designer. Spectre APS is the recommended solver to start with any EM/IR performance or accuracy evaluation of small design block, or designs with smaller number of RC nets. It also supports both Direct and Iterated EM/IR analysis methods.

Note: EM/IR Analysis with AMS Simulator also supports power macro generation.

To know more about this feature and how to run it in Virtuoso ADE Explorer, check out the AMS EM/IR Analysis in Virtuoso ADE Environment videos available on the Cadence Online Support Portal.

Click the video link now or visit Cadence Online Support and search for Virtuoso videos under Video Library.

Related Resources

User Guide

• Virtuoso ADE Explorer User Guide
• Spectre Circuit Simulator and Accelerated Parallel Simulator User Guide
• Voltus-Fi Custom Power Integrity Solution XL User Guide

Workshop

• Voltus-Fi EMIR Analysis Workshop - The DSPF flow

Rapid Adoption Kit

• AMS Electromigration and IR-Drop (EMIR) Analysis
• EMIR Voltus-Fi XL for Advanced Nodes

Blog

• Spectre Tech Tips: How to Perform EMIR Analysis in ADE Using Spectre APS?
• Virtuosity: In-design Electromigration Analysis - An efficient way to make layouts electrically correct

For more information on Cadence circuit design products and services, visit www.cadence.com.

About Virtuoso Video Diary

Virtuoso Video Diary is an online journal that relays information about Virtuoso videos that are available in the Cadence Online Support Video Library. Hundreds of interesting videos on a wide variety of new and exciting Virtuoso features have already been created. Virtuoso Video Diary brings you direct links to these videos and other related material, on regular basis. Click Subscribe to visit the subscriptions box at the top of the page in which you can submit your e-mail address to receive notifications about our latest Virtuoso Video Diary posts.

Harsh Gupta and Vani Verma (Team Virtuoso)