If you really want to know how a new EDA product works, listen to someone who has thoroughly tested and used it. Verification engineers and managers got a chance to do just that at CDNLive Silicon Valley 2014, where a Hewlett-Packard engineer described his company's experience with Incisive vManager, a new Cadence verification planning and management solution.
The presentation was titled "Who's Covered That? How Adopting Database Technologies has Enabled Us." The slides are now available in the CDNLive proceedings archive. Authors are David Lacey and Ron Thurgood, and the CDNLive presentation was given by Lacey. The authors are part of the HP Enterprise group and their verification task involves ASICs and FPGAs for HP's server business.
(Just to avoid any potential confusion, let me clarify that vManager is a new tool with an old name. vManager was the original name of a product sold by Verisity before Cadence acquired the company in 2005. Cadence renamed that product "Incisive Enterprise Manager." The new Incisive vManager solution, introduced February 2014, has far more features than either of its predecessors.)
Lacey began by noting some of the challenges his group is facing - resources are shrinking, the scope of verification is increasing, schedules are shortening, and the need for quality in the first revision of silicon is growing. Their current verification approach is based on the Universal Verification Methodology (UVM), both UVM-e and UVM SystemVerilog, and engineers rely heavily on pseudo-random stimulus augmented with directed testing. "And then we are heavily metric driven, and that's where the coverage problem comes in," Lacey said.
A Home-Grown Effort
In the early 2000s, when HP started using coverage, no vendor tools were available, Lacey noted. So his group decided to develop their own tool. They started out with a list of requirements including multi-site support, multiple user access to files, data management, integration of coverage with test plan, advanced analysis, and more (you can see a comprehensive listing in the presentation). They created a solution that "did a pretty good job, given that we had to develop it all ourselves. But there are features that we didn't have enough time or resources to complete."
In the mid-2000s, HP engineers started to evaluate vendor solutions that were becoming available. They used Incisive Enterprise Manager, but it didn't meet all their requirements. The solution at that time was file based, making it difficult to support multiple users or multiple sites. "It required us to create a lot of infrastructure around the solution so we could actually get the data into the tools," Lacey said. HP worked closely with Cadence to try to improve areas where requirements were not being met.
A New Coverage Management Solution
Fast forward to today, where the Incisive vManager verification planning and management solution is based on a client/server architecture and an SQL database. "We are now finding that the Cadence tools, related to vManager and the coverage flows, are significantly improved from where they were when we first started looking at them," Lacey said. "We made the transition to adopt Cadence Incisive vManager flows for our team."
The toolset, he said, "actually does a really, really good job. We still have to create a little bit of infrastructure ourselves to make this all work, but we feel that the Cadence toolset is providing the vast majority of the features we need."
The presentation goes into some detail about the coverage flows enabled by the Incisive vManager solution. It shows how engineers get coverage data into the database, manage coverage files, and do some simple data management. It also explains the three tools that are behind the vManager solution - Incisive Metric Center (IMC), vManager Client, and vManager Server.
Basically, Lacey said, vManager Server is a central location for storage of simulation regression and coverage data. It is based on an SQL server and is easy to set up. vManager Client is the starting point for most users. Here, users can filter data and pull out what they want for further analysis. Once they have selected the runs they want to analyze, they then use the Incisive Metric Center to run various types of detailed analyses.
The presentation provides a simple use case example. If you want to analyze regression runs, the procedure is:
- 1. Launch vManager Client
- 2. Select desired session
- 3. Press metrics button in Analyze window
"And boom, you're ready to start analyzing," Lacey said. "It's very simple and easy to use."
The Bottom Line
The new vManager solution has helped HP engineers improve their productivity, Lacey said. He pointed to these advantages:
- No need for customized coverage tools
- Limited script wrappers automate tasks
- Test grading improves effectiveness of regression cycles
- Advanced analysis leads to faster coverage closure
- Potential for reduced simulation license requirements
- Powerful GUI empowers engineers
But there are also some future improvements HP engineers would like to see:
- Support for Accellera Unified Coverage Interoperability Standard (UCIS)
- Increased performance
- Move all data into the database
- Management "portal" for metrics
- Multi-site support for global teams
"So that's our coverage journey," Lacey concluded. "It's helped us produce high-quality chips that are used in servers across the world. The partnering we've done with Cadence has enabled us to drive features into its toolset and has directly impacted and benefited our team."
Slides for this and other CDNLive Silicon Valley presentations are available in the proceedings archive. A Cadence log-in is required to view the presentations - and registration is quick and easy if you don't have one. To find the HP presentation, click on the System-to-Silicon Verification I tab.
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