DVCon is a great place to talk to design and verification engineers. As the Accellera Portable Stimulus Standard (PSS) gets closer to reality, we were able to share with them during the conference the progress made and the ways in which it may impact their task. Most of them are as excited about PSS as we are. While we have been working in this field for more than a decade and have received a lot of feedback, there are now many more people becoming aware of it and the potential that it has. This provides us with the opportunity to learn as well. (more…)
Posts Tagged ‘system coverage’
For those unfamiliar with the idiom, “hitting the town” or “going out on the town” means heading out to make the rounds of bars, restaurants, theaters, clubs, etc. It’s usually used in a city where such entertainment options abound. The topic of today’s post on The Breker Trekker blog is a particular club, DVClub, that packs in plenty of solid technical information along with entertainment. You may not have to go far to hit one; a DVClub event is likely to be coming to your city soon.
The history of the Design Verification Club (DVClub) is quite interesting, stretching back more than ten years. It started as an informal event for verification engineers to get together to share stories and talk about new technologies to help them do their jobs. You might have noticed that, unlike DVCon, the title means “design verification” and not “design and verification.” This gathering is intended for semiconductor functional verification engineers.
When we first began offering our Trek family of products for what’s now known as portable stimulus, we talked a lot about vertical and horizontal reuse. Vertical reuse means that you can create a scenario model for individual IP blocks and generate test cases to run in their UVM testbenches, then move up to clusters and subsystems. The IP models can simply be plugged together to form a higher-level model from which appropriate higher-level test cases can be generated.
At the full-SoC level, you can generate C test cases that run on your embedded processors. Horizontal reuse is the ability to move from simulation to hardware (acceleration/emulation, FPGA prototypes, and silicon) while generating appropriate tests for these platforms from the same SoC scenario model. We generally described both forms of reuse in a unidirectional flow. However, bidirectionality is very valuable and, we believe, essential for portable stimulus. Let’s cover that topic in today’s blog post.
Recently, SemiconductorEngineering published the three–part series “System-Level Verification Tackles New Role” as part of its ongoing “Experts at the Table” discussions. The format is simple–an editor sits down with four or five industry experts to discuss a particular topic–but the debate can be lively and the result educational. Breker participates in these roundtables as often as we can, focusing of course on verification among the many technical topics covered by the site.
In advertising a “new role” for system-level verification, this particular series was not overstating the case. We tend to talk a lot about the evolution of verification in general, especially for system-on-chip (SoC) devices and multi-SoC systems. But in some ways what is happening now with our products and the Accellera portable stimulus standardization effort is more revolutionary than evolutionary. So which is it? We’ll attempt to answer that question in today’s post here on The Breker Trekker blog.
Over the more than three years of posts here on The Breker Trekker blog, you’ve seen us reference our TrekBox runtime component on many occasions. We mention it in many contexts: test case visualization, memory usage visualization, test case status, test case debugging, system-level coverage, performance analysis, I/O interfacing, UVM testbench control, and more. We’ve never had a post on TrekBox itself, so today we rectify that and fill in a few details that we haven’t discussed before.
Some of you are familiar with the term “trickbox” in the context of a simulation testbench. We found a nice concise definition of this term in an ARM patent: “Memory mapped (behavioral) test bench component to facilitate verification.” By writing to designated memory addresses, the processors in the design being verified can send messages to the testbench for various actions. Our TrekBox is of course a play on the “trickbox” name, and it provides many presents inside for those who open it.
As I discussed at last week, there are many different engineering roles involved in the development of a large, complex semiconductor device. The EDA industry attempts to serve nearly all of these groups, from the architects and product marketing engineers who dream up the new ideas to the technicians who test production parts on the factory floor. Today I’m focusing on the work of two of EDA’s most traditional customer bases: hardware designers and hardware verification engineers.
Perhaps I’d better explain my title. It comes from an old expression “we went to different schools together” that I remember hearing as a youngster. Sometimes this refers to two people who didn’t actually attend the same school but who are nevertheless longtime close friends. But I’ve also heard it used to refer to two people who did in fact go to school together but had very different experiences. This latter context is the one I have mind for design and verification engineers who work on the same project yet inhabit different worlds.
It’s been more than a year since we presented the Breker view of system coverage in detail, so it’s time to revisit the topic. We first defined the notion of system coverage as measuring which realistic, system-level application scenarios have been exercised using the existing test cases. We then demonstrated how our graph-based scenario models are ideally suited to capture system coverage metrics and fine-tune them using graph constraints if needed.
More recently, we noted that the term “use cases” has become more widespread and introduced the example of a digital camera SoC to show the types of use cases that should be exercised. The measurement for this exercise is also system coverage, so the bottom line is that all these terms are really talking about the same thing. Using a regular expression, we might say:
[application|realistic] (scenario|use-case) coverage = system coverage
It’s becoming somewhat of a tradition here on The Breker Trekker blog to close each year with a list of gifts available from us to verification engineers. We started the series two years ago with an initial list focusing on our core benefits of automatic test case generation, system coverage, and reuse both vertically (IP to system) and horizontally (simulation to silicon). Last year’s post offered five more gifts reflecting additional products and new features added to our overall solution:
#5: Easier sequence specification in UVM testbenches.
#4: Faster coverage closure in UVM testbenches.
#3: Integration of system coverage with other coverage metrics.
#2: Debug of automatic test cases using standard tools.
#1: A fully automated solution for cache coherency verification.
Every one of the ten gifts from 2013 and 2014 is still available today for our customers. In addition, we have continued to evolve our Trek family of products and to deploy it on ever more challenging SoC verification projects. Without further ado, here is our all-new list of holiday gifts for the verification engineer in 2015:
Last year, we wound up in December with a post on the “Top 5 Holiday Gifts for the Verification Engineer” and it proved very popular despite the holiday timing. To refresh your memory (and ours), here is the 2013 list:
#5: Relief from hand-writing verification test code.
#4: Relief from hand-writing validation diagnostics.
#3: Vertical verification IP reuse from block to system.
#2: Horizontal verification IP reuse from electronic system level (ESL) to silicon.
#1: Effortless system coverage reflecting end-use applications.
As you might expect, every one of these gifts is still available today for users of our Trek family of products. But over the last year we have added two new products, many new features, and deeper integration into existing verification flows. So we’d like to wrap up 2014 with an all-new list of holiday gifts for the verification engineer. We hope you like them as much as you liked last year’s offerings:
The 51st Design Automation Conference (DAC) has passed into the history books with three days of exhibits and a wide range of enveloping technical sessions and tutorials. After returning home, I’m thinking back over the week fondly as I nurse feet that ache more than I thought possible. Before I get back into the usual work routine, I want to capture some of the impressions and thoughts running through my head.
There is no doubt that big forces in the industry are aligning toward our view of SoC verification with graph-based scenario models. Many of the people who stopped by our “USS Ice Breker” booth completely understood that they risked hitting an iceberg with their minimal full-chip verification efforts. Some had heard about Breker from colleagues or had seen us listed in Gary Smith’s and John Cooley’s DAC “must see” lists. Others knew little about us but were attracted by our claim as “The SoC Verification Company.” All wanted to know how we can help them.