UVM Still Isn’t A Methodology

A few months ago, I posted on an article on AgileSoC.com titled UVM Is Not A Methodology. The point of that article, was to encourage people to break away from the idea that verification frameworks like UVM truly deserve the label ‘methodology’.

In the article, I argue that to be called a methodology requires a number of other considerations go beyond the standardized framework and take into account the people using it:

  • A Sustained Training Strategy
  • Mentoring Of New Teammates
  • Regular Review Cycles
  • Early Design Integration
  • Early Model Integration
  • Incremental Development, Testing and Coverage Collection
  • Organization Specific Refinement

That article generated a lot of interest and a few comments. I got some complements from some people and some minor disagreement from a few others. I’ve summarize a few below.

Neil, you’ve outdone yourself. Excellent article IMO.

We’ll start with a good one :). I got that comment from a friend, a real expert in functional verification and a person I learned a lot from when I decided to specialize in functional verification. I really appreciated that.

Neil, UVM _is_ a methodology, but not in the same sense as you have described in your blog post. It is a methodology that provides a framework for designing and building testbenches… You are correct that it is not a complete verification methodology covering all the things you list. All of those things certainly have to be addressed by each verification team, but can they be standardized? Training, mentoring, and reviews are essential to a good verification methodology, but it would be difficult to provide meaningful standards beyond what is already in the software engineering literature. (read the unedited comment here)

That isn’t totally agreement but I took that comment as an acknowledgement nonetheless that in order to be complete, a methodology has to go beyond the framework to include some of the things that I identified. The fact that they can’t be standardized is a good reminder that teams using frameworks like UVM need to worry about the extra stuff themselves. No one can do that for them.

The article makes some valid points but falls into the same trap that I think a lot of people do; i.e. getting confused between the UVM code library and UVM the methodology … My personal view … is that the customer teams who insist on self-learning the eRM/URM/OVM/UVM library or the (e, SC, or SV) language and won’t ask for training or guidance are the ones who end up getting the least from the methodology…These same users achieve far less reuse and randomisation than they should be getting, and the effectiveness of their testing is much lower than it should be. Where customers have invited me in to help architect their flow … we’ve created some really nice modular environments that are reusable, maintainable and adaptable. These customer teams have become more productive and have then propagated that methodology experience to other teams in their company, much as the article describes. This is the real UVM, where code meets experience … I’m saying this not to boast about…my own abilities, but to stress the point that getting all fired up about a code library isn’t going to make you more productive or effective, there’s a whole lot of hard work and care goes into really building a good UVM testbench. (read the unedited comment here).

Again, that comment isn’t total agreement but it does highlight the fact that UVM is larger than a code library and that mentoring plays a big part in how effective teams can be when using it.

The last paragraph of that article states it properly. It is a framework you can build a methodology around, but it is not a methodology in and of itself. The fact that it took the author 1600 words to state that simple fact indicates the article is mainly marketing fluff from a consulting company trying to scare managers. Much like calling UVM a methodology is EDA marketing fluff to convince managers it is more than just a framework. (read the unedited comment here)

That one was my favorite! Complete agreement followed up with the accusation of fear mongering!

Always nice to see people taking the time to comment 🙂

neil

Q. What do you call UVM? Methodology? Framework? Something else?

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