Designing for the Long Haul

There is a story in the American South about two “country boys” who walk into a lumber yard and ask to buy some wood. The lumber yard attendant asks what size they want. They look confused. He gives them some choices “two-by-fours, two-by-sixes, four-by-fours…”

They step aside for a minute to confer with each other. “We’ll take two-by-fours.” 

The lumber yard attendant takes them to the aisle with the two-by-fours. “How long do you need them?” 

The two step aside to confer again, whispering frantically to each other.

“A long time – we’re building a house!”

When we choose EDA tools, we typically don’t think much about longevity. Our design horizon is often reaching beta test or production, and it’s hard to think much about time beyond that – except to visualize ourselves on a tropical beach with an umbrella-bearing drink watching the sun set – both literally and on our project-related stress.

If you design custom ICs, your planning process is probably more robust, but your design horizon is still relatively near. In all likelihood, your chip will be obsolete in a couple of years, and nobody will care what design tools you used for your original project. If you created IP of value, it will be easily archived and theoretically re-usable. (You DID follow all of the relevant industry standards and guidelines to make your IP re-usable, didn’t you? Yeah, we knew you did. Mum’s the word.)

If you design something with larger geometries, however, like PCBs, cabling harnesses, or more elaborate systems, your design isn’t captured in something as simple as a few lines of VHDL or Verilog. Again, for most applications, this isn’t a problem. If your design needs to be changed in a few years, you will still have most of the same tools, and if the EDA vendor was responsible in their subsequent releases, you’ll still be able to read those old data files in the new version and make the required changes (even though looking at some of the things you did design-wise “way back then” may make you cringe a little. Easy does it! Fix ONLY the things that you need to change. Don’t go on a cleaning spree. Move away from the mouse…) 

What happens, though, when a LOT of time passes between the time a design is first created and the time we need to get in and do something important to update it? For those of you who spend your careers in the fast-paced markets like consumer electronics, you may find such a scenario difficult to imagine. But, in many heavy-iron industries like automotive, there are lengthy standards in place to deal with just such eventualities. What happens when you need to make a hardware change in a design that was deployed thirty-odd years ago in a system that’s still in the field. Have you still got a working copy of your GenRad HiLo simulator? Do you still remember GHDL? Does that Apollo workstation in the basement still fire up? How about that CALMA station? 

Uh Oh.

In this fast-paced world where we sometimes find ourselves racing the clock to get our designs shipped before they become obsolete, it’s easy to forget about the long haul. It’s hard to justify spending valuable engineering time thinking about creating a design time capsule for a future engineer (presently age two) that may be working in the company that bought the company that acquired the division that was sold to the big conglomerate that will buy the start-up you’re working for next year. THAT dude is just on his own, right?

For EDA companies, the challenge is similar. The focus is on making money this year, or even this quarter. Customers buy tools based on what capabilities they bring to the table right now and how they handle the massive design challenges we face with today’s frenetic pace of technology evolution. You don’t often get a customer coming to your EDA sales team asking, “How will I fire up this tool in thirty years if I need to make a design change?” 

“You mean on your head-mounted quantum computer with neural user interface?”

EDA companies do a great job handling this problem for the reasonable time frames we’ve all dealt with in our careers. They make sure old design data is generally forward compatible and that standards exist for some manner of interoperability in cases where an EDA company might go out of business unexpectedly. Daisy and Valid customer support aren’t answering too many calls these days.

However, we are really just reaching the time when this becomes a real issue for the industry. Before the early 1980s, most design was done on paper, and those rolls of blueprint seem to be pretty forward-compatible. In the 1980s, however, a large percentage of the world’s engineering moved over to electronic design automation systems. We are just now reaching the era where this will start to matter. Engineering careers span something in the range of thirty years, so the people who did those designs are beginning to exit the industry. Second and third generations of EDA-using engineers are already coming up in their places. The tools those early EDA users adopted are in a woeful state today. Most of them used proprietary computing systems, long-obsolete operating systems, and proprietary design data formats. If you wanted to go back and fix that one flaw in the flight control system your company designed in 1984, you’re in a bit of a pickle. 

Well, almost.

There is a bit of a bright side to this scenario. Some of the longer-lived EDA companies have noticed this problem and actually found a way to turn it into a benefit – for themselves AND their long-term customers. Mentor Graphics, for example, has a team dedicated exclusively to supporting customers on long-obsolete tools. For a price, they will go on a software archaeological dig, unearth that copy of XYZ-whatever tool source code from 1985, port it to a modern operating system and computing platform, and help you get your grandpa’s design up so you can replace that one TTL part that isn’t available any more. In Mentor’s case, they don’t even restrict themselves to Mentor tools. They have a repertoire of tool technology from long-dead startups that might be just what you need to save your bacon someday. 

Services like this are highly profitable for the EDA companies that provide them and potential lifesavers for the companies that use them. While they address only a fraction of the design archival issues that we all face, they do bridge the gap to an era where EDA itself was new and naïve and mass-produced computing hardware couldn’t handle the needs of electronic designers. However, we can all make great strides for the future by simply thinking about the longevity of our designs, anticipating what kind of changes might be required in the normal evolution of our product, and leaving at least some breadcrumbs for future forensic designers to follow in re-tracing our footsteps.

Well, time to go back and watch some of those 8mm family movies.

Image courtesy of the Computer History Museum