This year's One Powerful Issue takes on special significance given the widespread worries about global warming. With last month's unsettling report
from the Intergovernmental Panel on Climate Change, energy efficiency is
now sizzling on everybody's front burner. Instead of cleaning up wasted energy via ever more elaborate cooling schemes, engineers
are now thinking about power efficiency as one of the first
tenets of good design.
Power efficiency was one of the central themes at
last month's DesignCon conference in Santa Clara,
Calif. Paul Platt, IDT's vice president of design service, told a panel audience that "power is now the
top issue in design, and not just for the low-power guys working on portable products. Power bills and cooling costs are going through the roof at server farms."
Too often, manufacturers conduct power analysis "after the fact," Platt said. And while today's design tools allow some power efficiency modeling "at the architecture level, designers are not really getting the help they need. The tools need to offer more guidance early in the
process," he said.
THE INDUSTRY'S VIEW
Brendon Farly of Silicon and
Software Systems agreed, adding that new consumer electronics are creating a power crunch when it comes to scaling and
leakage problems. "The challenges for lower power have really
taken the industry by surprise," said Farly, citing the leakage
issues at 130- and 90-nm process nodes. Design methodology
must be adjusted to solve these problems, he said.
Steve Carlson, Cadence's vice president of product marketing, agreed that power is today's crucial issue, noting that
designers are even "dusting off" water cooling as a solution to
overheated networking systems. He said that front-end/chip
designers have had a "hall pass" when it comes to power
issues, but it's time for that to change.
Chip designers have tended to overdesign the margin for timing closure, he said, which has an impact on power and die
size. "I'm going around challenging designers on the over-constraining of clocks. It's time for evolution to a more directed
approach to determine the margin needed," he said.
Leakage analysis often is applied across the entire design
using a worst-case scenario, when the reality is that 10% of the
transistors are causing 90% of the leakage. It's understandable
that designers want to include a safe margin of error, but Carlson said that new tools allow designers to see the tradeoffs earlier and make more informed design choices.
The hitch, said Carlson, is that learning to use the new
tools takes time, while designers are under constant
pressure to get their designs out the door. He called
engineers "agents of change," but he said they
need support from their managers to allow the
time to adopt new technologies—and get the
best return on investment. Designers are
understandably conservative in an era where
mask sets cost millions and "nobody has a
problem as long as the schedule stays
the same," he said.
OUR VIEW
To explore some of
the new power-optimizing design
tools, see our Engineering Feature,
"We Have Seen The Enemy, And The Enemy Is Heat" by EDA
Editor David Maliniak. Moving up the design chain, our
One Powerful Issue includes all of our regular departments,
but with unique angles on power efficiency.
Our Leapfrog articles describe SMSC's temperature sensors
and fan controllers that help "beat the heat" and also Intel's
breakthrough high-k solution for leakage power.
Contributing Editor Sam Davis breaks down power management subsystem design in this issue's Engineering Essentials . Zooming out to the macro side of the power continuum,
Analog/Power Editor Don Tuite investigates electricity metering
in his Technology Report .
Don reminds us that power design is part of an energy ecosystem—every milliwatt of efficiency designed in at the chip level is a
milliwatt of power conserved when the meter is rolling. Global
energy use and electronic design are part of the same power
continuum. The further back in the chain we can design in power
efficiency, the less "cleanup" we'll have to do later.
There is still skepticism among some engineers as to the
reality of global warming. But from an electronic design perspective, aiming for maximum power efficiency is a win/win
equation. As consumer demand and government policy focus
more on conservation, green products and their designers
will ride a rising tide, leaving low-efficiency "power hogs" in
their wake.