Keeping the “E” in ESL
I was in Boston last week and I met with a few customers who shared information about their activities around ESL. I’m always pleased to meet with customers who are already down the path of ESL. However, I’m often surprised to hear what constitutes ESL for them. In this case, the customer was creating very high level, conceptual models of a system, also known as model based design, to represent a wide range of engineering disciplines across the system (HW, SW, Thermal, Optical). I noted that the models had no representation of actual hardware, just functions in concept which may or may not ever be in actual hardware.
The next night, I was in Philadelphia, at a renowned cheesesteak sub shop, where I watched the Phillies clobber the Dodgers, all the while raising my cholesterol with a great sub. Earlier in the day, I met with another customer who said they were interested in applying ESL and were planning to start by creating UML models. In less than 24 hours, I had met with two customers with completely different concepts of ESL. Interestingly, neither concept–the model-based design or the UML modeling activity–really fit within my definition of ESL. Specifically, both methodologies neglected the “E” in ESL. The E in ESL implies electronic hardware and some representation of that implementation.
While ESL is certainly a design representation above RTL, that doesn’t mean it encompasses every abstraction above RTL. ESL starts and stops within the abstraction of TLM (transaction level modeling), which includes some representation of hardware architecture. While there are certainly benefits and good reasons to also do conceptual modeling, above ESL, lumping those methodologies into the ESL bucket dilutes the space and risks confusion in the market. ESL is a major step in hardware design methodology above RTL and a logical progression in hardware design methodology. Given the long history of ESL, as we watch it come of age, it seems like a good idea to maintain clarity as to what is and is not within this design methodology.