Ok, I’ll admit it,
I’m a bit of a leadfoot. I like to go fast, especially off stop
lights. Maybe it is the competitive streak in me, but I love to be the
first off a light. Or maybe it is just me showing the BMW drivers that my
Hyundai can go just as fast.
I also do a lot of
traveling, and so end up in a lot of rental cars. Hertz might cringe at
this, but is there anything better than winding up a rental car? Now
before anyone yells at me, I’ve got a stellar driving record (touch
wood). But there’s something about a new rental car and a light turning
green that turns me into Mario Andretti.
On my last trip to San Jose, I hopped off the
rental car bus (aside – is there another airport as, um, messed up as San
Jose??). And found to my
surprise that they had given me a Prius. Ok, why not? One advantage
of traveling is you get to try different cars. I still get a smile on my
face when I recall the cherry red convertible T-Bird I once got. I’d give
the Prius a whirl. Could be fun. Or maybe I could figure out why
Now the thing about a
Prius (forgive me if you know this) is that it has a big screen on the
dashboard showing instantaneous mileage. So you can see at any moment in
time exactly how much energy you’re consuming. And you can see the
mileage over time – how are you doing during the trip. Pretty cool idea.
So here’s what
happened. In a strange video game kind of way, I started to try to
maximize the instantaneous mileage. I found that I could get better
results if I didn’t blow off the light. If I coasted up to the light, the
same results – 99MPG. I found myself getting irritated when the gas
engine turned on, and the mileage dipped. In short, I started driving
responsibly, all because of this dumb screen showing me how I was saving or
Nirvana came to me on
the third day, when I got the car up to the right speed, and then maintained
that with a light touch on the pedal. The result – the car was only being
powered by the battery. I ended up with 99MPG for about 5 minutes –
YES!! Just by getting feedback, I changed from a leadfoot to maintaining
the perfect balance.
Ok, there is a point
to this (I’m imagining you saying, “Get on with it!!!”). As my colleague
Jack Erickson has pointed out (here),
getting feedback on energy use is the first step to doing something about
it. And there are finally some EDA tools to help accomplish this.
One that is particularly interesting is Dynamic Power Analysis with the
Palladium system. DPA allows you to measure the power during real
operation, including running software applications. The power engine is
based on the power analysis built into RTL Compiler, so it is production
proven. DPA was just named Product of the
Month by Portable Design Magazine.
The nice thing about
this is that there’s only a minor modification in methodology to get the
feedback. So if a design team is using Palladium to validate system
software or design operation, there’s no real reason why not to perform this
power analysis. The same is true of other EDA power analysis and
optimization engines – they’re largely there, waiting for use. Using
these systems, you’ll measure the power of your design and system. And
measurement is the first stage to doing something – balancing the software
load, implementing shutoff or MSV, implementing clock gating – something.
If you use these tools, it really could be easy to be green.