Thought Leadership

Portable Stimulus Takes an Important Step Forward

By Tom Fitzpatrick

As a leading proponent of Accellera’s work in the Portable Stimulus Working Group (WG) for a couple of years now, we wanted to update you on the latest significant milestone in the process. After many months of evaluation and discussion, the Working Group has decided to base its standard on the domain-specific language (DSL) contribution made by Mentor Graphics and Cadence Design Systems. The DSL combines the graph-based stimulus-specification approach used by our Questa inFact testbench automation tool with a model-based approach used by Cadence’s Perspec tool, providing several advantages to the user. By a near-unanimous majority, the members of the working group decided that this DSL is the best vehicle to use to define the semantics and syntax for Portable Stimulus.
At the same time, the WG also agreed to develop a C++ input format for Portable Stimulus that will be semantically equivalent to the agreed-upon DSL. This input format will be based on the contribution from Breker Verification Systems, which is a C++ library that they’ve been updating pretty continuously in an attempt to match the semantics of our DSL, but there’s still a lot of work to do there. It’s not yet clear how much a semantically-equivalent C++ input format would resemble the current Breker proposal, and we (Mentor and Cadence) have some ideas in this area that may help us arrive at the right solution.
The real key here is that the WG recognized that, even though a domain-specific language is a fundamental requirement for a portable stimulus solution, there is a large contingent of potential users who prefer writing their tests in C++. By having the standard support both input formats, and ensuring their interoperability and semantic equivalence, we will have portability between users and between vendors, as well as the inter- and intra-project portability that is the main technical goal of the WG.
If you’d like to participate in the Portable Stimulus Working Group (and your company is an Accellera member), you can sign up here. If you’d like your company to become an Accellera member, see here.


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This article first appeared on the Siemens Digital Industries Software blog at