editor's blog
Subscribe Now

Using Formal to Help Simulation

While simulation is the granddaddy of verification, there are thorny problems that simulation doesn’t handle well, and formal analysis has gradually come of age over the years to attack those problems. So the two technologies end up working side by side on different issues to complete the verification plan.

While that is still largely true, Mentor has added a feature to their Questa verification platform to allow the formal part to help the simulation part. The formal part can help determine the simulation coverage; the feature is called CoverCheck.

The formal analysis engine can walk through the code and determine both unreachable code – you’ll simulate forever trying to reach that, with no improvement – and a sensitization path to hard-to-reach code. It’s essentially saying, “Don’t bother going here; you’re wasting your time. And for these other bits, here’s how you cover them.”

Unreachable code is dead code, and for some applications, dead code is verboten. Mission- and safety-critical design practices tend to require that every requirement be traceable to code and all code be traceable back to a requirement. So dead code, by definition, since it doesn’t do anything, can’t be tied to a requirement. While Mentor isn’t aware of anyone taking this next step yet, CoverCheck could be used to excise such code.

In addition, they’ve added a more classical formal feature called AutoCheck. It looks for common problems in the code (think “lint,” but different problems). Examples of the things it can verify are X-propagation, combinatorial loops, state machine deadlock, and overflow.

Both CoverCheck and AutoCheck are push-button automatic.

Finally, they announced performance improvements in their clock-domain crossing (CDC) formal capability.

You can find more in their release.

Leave a Reply

featured blogs
Aug 13, 2020
My first computer put out a crazy 33 MHz of processing power from the 486 CPU. That was on “Turbo Mode” of course, and when it was turned off we were left with 16 MHz. Insert frowny face. Maybe you are too young to remember a turbo button, but if you aren’t ...
Aug 13, 2020
Hi readers! Welcome to Veri-Fire, a blog series that helps you deep dive into Virtuoso® ADE Verifier and learn about its various whys and hows. In this series, Walter Hartong, a Product... [[ Click on the title to access the full blog on the Cadence Community site. ]]...
Aug 13, 2020
Imagine ambling into a small town, heading to the nearest public house to blow the froth off a few cold beers, and hearing your AI whisper '€œ...'€...
Aug 7, 2020
[From the last episode: We looked at activation and what they'€™re for.] We'€™ve talked about the structure of machine-learning (ML) models and much of the hardware and math needed to do ML work. But there are some practical considerations that mean we may not directly us...

Featured Video

Product Update: New DesignWare USB4 IP Solution

Sponsored by Synopsys

Are you ready for USB4? Join Gervais Fong and Eric Huang to learn more about this new 40Gbps standard and Synopsys DesignWare IP that helps bring your USB4-enabled SoC to market faster.

Click here for more information about DesignWare USB4 IP

Featured Paper

Computational Software: 4 Ways It is Transforming System Design & Hardware Design

Sponsored by BestTech Views

Cadence President Anirudh Devgan shares his detailed insights on Computational Software. Anirudh provides a clear definition of computational software, and four specific ways computational software is transforming system design & hardware design -- including highly distributed compute, reduced memory footprints, co-optimization, and machine learning applications.

Click here for the white paper.

Featured Chalk Talk

Consumer Plus 3D NAND SD Cards

Sponsored by Panasonic

3D NAND has numerous advantages, like larger capacity, lower cost, and longer lifespan. In many systems, 3D NAND in SD card form is a smart move. In this episode of Chalk Talk, Amelia Dalton chats with Brian Donovan about SD 3D NAND in applications such as automotive.

Click here for more information about Panasonic Consumer Plus Grade 3D NAND SD Cards