Hardware Bugs Need to Die

I used to accept bugs as a part of what happens in hardware development. Start a new project, write a bunch of code, deal with the bugs that inevitably arise, stress out about whether I can fix them before development milestones, cross my fingers that regressions pass the day before tape-out, repeat.

After several years of acceptance I’ve started taking bugs personally. I hate bugs. They’re no longer acceptable and I’ve changed the way I write code to avoid the embarrassment of creating them. For me that means using SVUnit to unit test my testbench code as I write it.

Knowing that test-driven development and unit testing with SVUnit has improved my code in every way, that others have found the same and that it’s become an option for everyone, I’ve turned advocating for SVUnit into a bit of a hobby…


svunit-smokes

I’ve grown to attribute bugs not so much to developer ability or quality of specification or language or other commonly held positions but to the habits we rely on to write design and testbench code. Primarily, I’m talking our debug later approach to writing code. Write the RTL then debug the RTL; write the testbench then debug the testbench. We don’t think about it, we just do it. It’s a habit. It kills our productivity, just like cigarettes kill people.

While EDA reacts to long debug cycles by investing in new debug tools, the only way I see to improve quality is by adopting proactive coding techniques (test-driven development being one option that I personally use. There are others). But before we do anything, we need to realize that bugs are formed out of habit. Kick the habit and voila… fewer bugs. Continue reading

Leading the Discussion on Unit Testing

Screen Shot 2016-05-25 at 9.04.54 PMAbout a month has passed since the great unit testing discussion in the Verification Academy booth at DAC in Austin. It was my second year in the booth. Very grateful for having had the opportunity. It was a lot of fun!

The format involved me cycling through a bunch of questions and comments on unit testing as a series of topics during which time discussion would erupt with me and audience.

At least that was the plan! Continue reading

5 Steps to Unit Testing Success

Seeing unit testing catch on and flourish with a new team has made the last few months at work pretty fun for me. Getting to this point, though, has been a ton of work. Considering the journey toward unit testing can have a lot of twist, turns, surprises and disappointments, I figured it would be a good time to recap in hopes my experience helps others grow unit testing within their teams. Continue reading

Simple Clock and Reset Support in SVUnit

Screen Shot 2016-04-28 at 8.54.17 AMIn a post a couple weeks ago called Sorry Design Engineers, I Can Do Better, I told design engineers that I’d do a better job of giving them what they need to unit test their RTL. I felt like I’ve been neglecting design engineers and decided I needed to set a new, more inclusive course. Tonight I took a first step in that direction. I’ve released SVUnit 3.10 with a simple clock and reset utility that’ll make it easier for design engineers to unit test synchronous and asynchronous logic. I also recorded a 25min code demo for design engineers to show how they can use SVUnit to unit test RTL modules. Continue reading

SVUnit for Chip Leads and Managers

Advanced verification methods put chip leads and managers at a real disadvantage, especially when it comes to visibility and predictability. With long testbench development times, early progress in constrained random is essentially based on trust; being random, the inherent uncertainty makes predictable scheduling and release milestones rare. Continue reading

Join the SVUnit User Group

One suggestion that came out of the SVUnit User Group Lunch last week during DVCon was a mailing list so that SVUnit users could keep in touch with questions, etc. Sounded good to me so I’ve set up an SVUnit User Group. It’s a google group. Anyone can join.

With the lunch being a great first step (for me it felt like a giant leap) in building a real community around SVUnit, my hope is that this is the natural next step giving us users an online home to congregate and support each other.

If you’re an SVUnit expert, someone entirely new to SVUnit or anyone in between, I hope you’ll join us in the SVUnit User Group to share your questions and experience!

-neil

SVUnit Training on Verification Academy

Screen Shot 2016-02-22 at 4.19.12 PMWe’ve hit a notable day in SVUnit history today with an hour training course going live on Mentor’s Verification Academy.

An Introduction to Unit Testing with SVUnit is a 5 part video course. It starts with my opinions on how advanced verification methods have failed to reach their potential, goes on to introduce SVUnit with a couple of coding examples and finishes with data from case studies that show the value of unit testing with SVUnit.

While the course is meant to flow naturally beginning to end, each of the 5 parts stands well on its own. Depending on what you’re after, here’s a little guidance on what sessions and details are best for you… Continue reading

SVUnit Improves Support for UVM

 

Version 3.8 of SVUnit, just released, improves support and usability for people unit testing UVM components.

Download the Latest Version of SVUnit from GitHubBut before we talk about new features, I want to mention that the cool part of this release… for me anyway… is that I didn’t have to do anything! Colleen Piercey and Dave Read, colleagues of mine from XtremeEDA, are responsible for adding and testing the version 3.8 features. That makes Colleen and Dave the newest active contributors to SVUnit!

As far as new 3.8 features, people can now use create_unit_test.pl to generate a UVM specific test case template. The template gives test writers placeholders for connectivity in an auto-generated UUT wrapper. It also inserts file includes, package imports and required function calls in the setup and teardown to avoid people having to do it themselves. Importantly, the new UVM test case template compiles and runs with UVM as-generated so you start writing tests from a known good state. Continue reading

Inaugural SVUnit User Group Lunch

svunit-tagThe inaugural SVUnit User Group Lunch will take place the week of DVCon in San Jose. Bringing SVUnit users together is something I’ve wanted to do for a while. So much so that I’ve held off using the word ‘inaugural’ for my entire life, saving it for exactly this moment!

Details are still being worked out, but so far it’s looking like lunch time, Wednesday March 2, somewhere near the Doubletree Hotel in San Jose. It’ll be an informal gathering where developers that are either using, evaluating or thinking of using SVUnit can get together, get to know each other and share experience and opinions. We’ll have room for about a dozen people (happy to say I’ve got 3 confirmed already).

This is an important community building exercise that I’m pretty excited about. With the SVUnit user base growing, now seems like the right time to start learning from each other. If you’re an SVUnit user and/or you want to meet other SVUnit users over lunch, please let me know at: neil.johnson@agilesoc.com. I’ll follow-up with details as they get sorted out.

-neil