Yesterday I spent some time with Eric Lish, the Chair of OSCI. Eric is an Intel veteran, having spent 21 years, and counting, with "the other big blue" company. At present he manages the Virtual Platform Center of Excellence in Chandler Arizona.

In discussing OSCI's past achievements and future plans it became clear to me that if one had to identify the single most important contribution the consortium has made to EDA, one would have to choose TLM. Transaction Level Modeling was not a new concept before OSCI turned its attention to it. VHDL, in fact, the greatly misunderstood and poorly marketed language, can in fact be used for architectural exploration and modeling at the transaction level. But that is mostly water under the bridge, and there was the need to open the possibility of real architectural design in another environment, free of the legacy of the past.

SystemC without TLM would be just another modeling tool that uses the freely available C language to diminish the cost of digital design modeling by allowing cheaper and faster simulations. But by itself it does not introduce any new paradigms. The development and standardization of TLM, instead, allowed a significant change in the way designers approach architectural exploration. It is now possible to partition functionality, design a number of interfaces among functional blocks, and efficiently explore a number of possible architectures for a given design. And, this is important, to do so using third party modules even if they are not available in source code.

I do not think we have given enough credit to OSCI for this fundamental step forward to truly enable the ESL market. Gary Smith is fond of repeating at every opportunity that Brian Bailey correctly predicted that the ESL market would grow through the growth of verification tools. But this observation misses a fundamental point: verification tools are useless without a design to verify. And before the introduction of TLM, such designs were expensive to realize, and thus ESL was not of much use, verification tools or not!

We must resist the appeal of the easy quote: our industry is complex and rests on some fundamental principles. One of them is that you cannot verify what you do not have. And, by the way, this principle also plays an important part in making verification a very expensive development step, often the most expensive in fact.

Appropriately the SystemC Users Group meeting was held the first day of DVCon, the conference dedicated to verification topics. Thanks to TLM we now have stuff we can verify at the ESL level.