With transaction-level modeling (TLM) and virtual prototyping gaining more traction with designers, the time is ripe for improved access to both information about TLMs and the models themselves. To that end, Synopsys has launched TLMCentral, which it terms the industry’s first open Web portal for developers and users of TLMs.
TLM has come a long way since its inception with the launch of the Open SystemC Initiative (OSCI) in 1999, which led in turn to the IEEE 1666-2005 SystemC standard and the TLM 2.0 standard in 2008. What’s been missing in the industry is an open, free repository for TLM know-how.
TLMCentral aspires to be that repository, currently housing some 670 models contributed by various intellectual property (IP) vendors, EDA tool providers, service companies, and universities. In fact, a quick look at TLMCentral’s Model Exchange page shows 724 entries as of this writing.
Recent research by VDC Research Group into the causes of project delays cites two key factors. One is escalating system-on-a-chip (SoC) complexity, and the other is the increasing amount of software to be written, tested, and integrated with the hardware.
Thus, the design and specification of the system architecture, development and test of firmware, and system integration must be tackled earlier, usually before any RTL is available for the hardware. This is where virtual prototyping with TLMs comes in.
Synopsys’s customers use virtual prototyping in many areas of their development cycle. According to Johannes Stahl, director of product marketing for Synopsys’s System Level Solutions Division, the number-one use is for development of device drivers. Other popular uses include application development, hardware/software integration testing, and software unit testing.
The biggest obstacle to broad deployment of TLMs and virtual platforms (VPs) has been a lack of understanding of how to deploy them. But the second most broadly cited issue preventing deployment was a lack of model availability.
“Just having the required model(s) to build the platform was a prominent threshold to cross,” says Stahl. “This is what TLM models written in SystemC are trying to address.”
Many pieces of IP have yet to be modeled, mostly peripherals that would flesh out an SoC design. Processors and interfaces are fairly well represented, but an open-source community can potentially fill in the gaps in what Stahl terms “environment models.”
TLMCentral aspires to bring together model developers including IP vendors, semiconductor companies, universities, services companies, and virtual platform users including OEMs, integrators, and semiconductor companies (see the figure).
For each of the models listed on the site, it provides a download function, contact information, listings of related models, an overview of relevant data, and datasheets. The model provider can optionally enable a ratings/comments function as well. Models can be filtered by abstraction level, IP type, bus interface, or market category.
A forum section gives users a place to request models from contributing providers or from peers who may be willing to donate. Also within the forum are an FAQ and best practices sections on modeling methodology and virtual prototyping methodology.