Advanced nodes are raising tough new
challenges for analog/mixed-signal and digital IC implementation, according to David
Desharnais, group director and product manager for implementation at Cadence.
In this interview, he notes where IC designers are struggling and succeeding,
and describes Cadence's 2010 strategy to help make customers more productive
Q: David, what does your job at
A: Every day I get to work side-by-side with the
sharpest minds in the world of electronic design - people who are working on
designs and design solutions for the biggest, most complex chips on the planet,
which ultimately find their way into the coolest products and gadgets that
change the world in which we live. I get
to be in the center of all the action, with customers, R&D, field
operations, and partners - right where I want to be.
I lead product management and marketing for our digital, full custom, and
analog design, implementation, and signoff verification offerings.
Q: What are the biggest customer
challenges in IC implementation?
A: When you
clear away all the fancy jargon and speak in everyday language, there are
really two main things designers and their companies are concerned about today
- how to be more efficient and effective in the design of their chips, and how
to make the most money from the chips they choose to make. Simply put, it all boils down to productivity
and profitability in the end.
are making fewer but significantly bigger bets on the designs they target. It used to be that companies would do 10-12
SoCs, hedging with the expectation that only a handful would have reasonable-or-better
market success. Today these same companies are only targeting 2-3 SoCs, and it
has become a very expensive proposition.
The success or failure of these SoCs can mean the success or failure of
the enterprise itself.
As a consequence,
these 2-3 designs are insanely large and complex - from the loads of
functionality that has to be shoehorned onto them, to the advanced process
nodes used to hit aggressive area or performance targets. Getting to the point where you have the most
competitive and differentiated die-size, performance, power, and yield for an
SoC is a Gordian Knot that somehow engineers need to find a way to cut through.
implementation engineers, it's a really crazy time. The shrinking of process
nodes and the sheer number of gates they have to deal with on a single SoC can
really throw a wrench in the works if they aren't prepared for it. New and more
severe factors come into play that design engineers traditionally didn't have
to worry about, like how to architect the clocks when the size of the chip
requires 2-3 clock cycles to traverse it, or how to optimize interactions of
multi-mode, multi-corner timing, power, signal integrity, and DFM [design for
manufacturability] in parallel.
Optimizing these things sequentially becomes a whack-a-mole situation.
are things like how to deal with parasitics from the board and/or package and
how they impact the silicon and vice-versa...and who's going to make sure that
all the team members are compliant and aligned.
The list goes on, but it comes down to about a 10X increase in
complexity for each major node transition.
Q: Does this complexity call for a
higher level of collaboration?
A: I would
say there is a bit of a paradox happening right now. To improve productivity, collaboration is vitally
important. However, the harder the
problem or challenge, the worse the quality of communication seems to be. You would want the opposite to be true to
solve problems in a more cohesive way. But, when you have a team in Texas and a team in India
and a team in Europe all working on various
blocks of an SoC, it is non-trivial.
to be done differently than in the past.
Flows have to be very coordinated, unified standards must be applied,
and full transparency is needed across all the pieces. Otherwise what you have is inefficiency and
waste. Complexity has compounded in a
very systematic way.
Q: What is Cadence's strategy for
helping customers with productivity and profitability?
A: To reign
in the productivity crisis, we need to help engineers harness complexity. One approach
we've taken is through recommended design flows and methodologies we call Foundation Flows. Our approach is
to bring downsteam intelligence up front in the design process and to provide
tight linkages, out-of-the-box scripts, and visibility from the system level
all the way down to final silicon.
Besides integration, we are also focused on establishing better handoff
points across the flow, data abstraction, and overall simplification - like
reducing the number of keystrokes or decisions that designers have to make in
the course of a design. All this is done
so designers can move their low-power or mixed-signal SoC to the next process
node with as few barriers as possible.
comes to profitability, our focus is to help customers create the most
differentiated silicon possible, getting them to market in a predictable
manner, and achieving the highest-yielding parts. For example, when we help a
customer gain an extra 3-4 points in yield on a high volume part, by showing
them how to optimize for DFM and yield right there in the design cockpit well
before silicon, this can make multiple millions of dollars in difference to
their top-line revenue, and it carries straight through to their bottom line
cycles that used to be 18 months or 2 years are 6 or 9 months now. And the
silicon has to work and work well. If you miss the window, you miss it
Q: What are you seeing in terms of
adoption of advanced nodes? Are customers moving on or staying put?
A: We see a
cautious approach by the industry. The bulk of the market is still at 130 nm or
90 nm, but definitely people are starting to move. Every conversation I have
with customers today includes advanced nodes and DFM - 40 nm or 32/28 nm, and
more recently even 20 nm. These kinds of designs can run into the $60-$100
million range, so there is a definite gut check that happens before taking the
want to know what to expect in terms of additional overhead they have to take
on, compared to the benefit they hope to get.
On top of this, they have to find enough of a market to give them
upwards of 80 million units to support that kind of investment. This kind of
volume typically means consumer, which also means advanced node, mixed-signal
and low power. Companies serving the consumer market are the trailblazers as
you might expect.
Q: There's been much talk about 3D
ICs with TSVs [through silicon vias]. Are you seeing customer interest, and if
so, for what types of applications?
definitely. It's a very exciting area. Customers are producing test chips and
production designs with TSVs already, and we have had longstanding partnerships
with foundries and heavyweight customers in this area going on for 3 years now.
is not new. It's been done for years. However, 3D with TSV is new and the
projections for growth in this area are high. A key driver is that a 3D IC gets you a better
form factor than a traditional side-by-side SiP, and brings significant
advantages in performance, low power, and time-to market. A 3D IC approach also
lends itself very well to design reuse and derivative designs.
electronics, wireless communications are by far the heavy users for 3D ICs, but
we also see customers in other applications, such as bio-medical devices and
automotive, moving to this technology now.
Q: What's been successful with low
power design, and what remains to be done?
A: We have
made great strides in low power, and we very much pioneered low power
automation for the EDA industry. Every piece of our flow entirely supports and
comprehends Si2's CPF [Common Power Format] today, and over the past two years
we've seen literally had several hundred designs tape out using the Cadence Low
Power Solution. Along the way, we
established mature, high-quality support for the various low-power techniques
in broad use in the industry, and we have automated advanced low-power
techniques like multiple supply voltages, multiple power domains, power
shutoff, dynamic voltage and frequency scaling, and disjoint power domains as
forward our objective is to extend our leadership in low power, and we'll
provide even more aggressive innovations like mixed-signal, variation-aware low
power support, and enhanced thermal analysis.
Q: How will Cadence move forward on
mixed-signal SoC implementation?
A: This is
a core strength for Cadence. We have the technology, flows, expertise, and a
significant user base that has been taping out these kinds of designs for over
20 years, and we continue to set the pace for new developments. We handle all
aspects - design, verification, and implementation of mixed-signal SoCs.
latest release of Virtuoso [IC6.1.4] alone, customers are seeing upwards of 30%
improvements in productivity. But
mixed-signal design is not just about analog or full-custom design -- it
requires strong digital technology as well.
And the convergence of our digital [Encounter] and analog [Virtuoso]
platforms drives many new opportunities for efficiencies across a mixed-signal
flow. Things like mixed-signal
floorplanning, block and chip-level electrical analysis, substrate analysis,
late-stage ECOs, unified constraints, and usability become very straightforward
when you integrate the analog and digital design, implementation and
verification worlds together. That is
very important for our customers and the industry overall.
Q: There are some new competitors in
the analog/custom space. How will Cadence maintain its lead?
A: We are
experts when it comes to analog and full-custom design, and we got this way
from working with leading edge companies around the world to achieve technology
breakthrough after breakthrough for well over 20 years. Every significant
design in the world today uses Virtuoso.
We have taken this experience and have folded this knowledge into our
tools. We never stop innovating
here. It's in our DNA.
example, we recently reinvented our entire analog/full-custom suite of tools
from schematic capture, environment, layout, automatic routing, and
chip-finishing with Virtuoso 6.1, and customers are experiencing a massive
difference in productivity and capability right out of the box. There is a lot you can do when you know
everything about the transistor -- how to build it, model it, simulate it, and
connect it, particularly in the context of mixed signal SoCs. We also constantly track flows and metrics
with our major customers and use the results to further enhance productivity
and the user experience.
will have to walk before they run. If customers want a place to walk, okay -
but we're light-years beyond that, and from what we see, designers cannot
afford to erase a decade of advancement in analog/full-custom design
automation, even if it is free.
Q: Cadence recently announced Encounter
9.1. What's special about
A: Last year we introduced a completely re-architected
digital implementation product line called Encounter Digital Implementation [EDI]
System. This has really been a hit with
customers. Our newest release of EDI System
- 9.1 - builds on this very high-capacity, multicore, integrated
infrastructure, and adds much more.
EDI System 9.1 to be our "productivity" focused release, bringing higher
capacity, performance, and usability, along with a full suite of integrated
signoff capabilities for timing, signal integrity, power, extraction, and
DFM. Heck, even the user-interface has
been completely rebuilt from the ground-up and now adds many analog-style
capabilities to address the requirements of very sensitive, high-speed clocks
and signal nets that take on more and more analog characteristics as the
process nodes shrink.
System 9.1 customers will find that we've built manufacturing and signoff
intelligence into what a designer does by default, so the quality of results
are significantly better. Also there is some
very exciting technology around design exploration and automatic floorplan synthesis. Not only can a designer can give the tool
some criteria, and it will automatically build a good floorplan that attempts
to meet the criteria -- it will actually leverage our multicore backplane to
automatically create multiple permutations of floorplans, and rank and rate
them from best to worst based on the criteria set. Our customers tell us that this capability
alone can take months off of the time it normally takes to arrive at an optimal
floorplan. Now that's what productivity
is about, right?
Q: What do you see as the most
exciting trend in implementation right now?
A: I think
the most interesting trends are in 3D-IC and in the bringing together of analog
and digital design to make mixed-signal SoCs.
friend told me once that doing analog design is like doing surgery. The surgeon has to do it all very hands-on,
methodically, and precise, and take the time to get it right. Improvements come in the form of new tools,
and better methods to drive more efficiency and performance without sacrificing
the quality. Conversely, doing digital
design is like being a race-car driver - it's all about performance, timing,
and breaking all the rules you have to, in order to get to the checkered
flag. As process nodes shrink the
racetrack turns from a nicely paved road to a bumpy dirt road. Improvements come in the form of absorbing
the shocks and putting on meatier tires and heartier equipment, and tweaking
the driving style to still win the race.
follow that analogy so far, then the punchline is that designing today's
mixed-signal SoCs is like asking that surgeon to jump in the racecar and do
surgery while going 200 mph down a bumpy dirt road. It's a problem the customers are trying to
solve. Design, implementation and verification across analog and digital
boundaries can be tripping points for customers. The most exciting thing for me
is the opportunity to tie all these together.