Hi and welcome to another in the Arm “What Is” program series. In each episode, we
dive into a tech topic to give you insight and perspective into some of today’s hottest
design trends. I’m Brian Fuller, editor-in-chief at Arm and today we’re going to find out
what is an ASIC?
And to help us with that, I want to introduce Rob Aitken, Fellow and Director of Research
with Arm. When he’s not helping us understand what is an ASIC, he’s introducing his four
grandchildren to the wonders of technology.
So let’s dive right in!
Rob, what exactly is an ASIC?
An ASIC is an application specific integrated circuit – so a chip that's designed to fulfill
some particular purpose to solve some particular problem.
So how does an ASIC differ from a standard off-the-shelf chip?
The key really is in the application specific part. It's doing something, usually it's doing
something that an off-the-shelf part isn't going to do. Occasionally, it's not doing
something that the application or the general part does, but mostly it's trying to add some
functionality that you can't get in an
off-the-shelf piece.
Now is an ASIC different from an SoC? Or are they the same thing? If they're different,
how are they different?
It's an excellent question. Historically, they were different and now they are somewhat
interchangeable. So historically, a system on chip was something that included a processor
in addition to whatever other custom logic functionality. Nowadays pretty much every
ASIC includes a processor or some sort so that the terms are somewhat interchangeable.
So Rob, why do engineering teams choose to design with an ASIC rather than use standard
chips?
I think the key is really achieving some capabilities,
some function they wouldn't be able to get
with standard parts or with any other solution. That's the primary driver for using an ASIC.
Secondarily, there are power and performance benefits that you usually get with a hardware
solution versus something implemented in software or on a standard part. And finally, there's
a cost benefit as well that when you build enough of a given design, it's cheaper to
do an ASIC than pretty much any other solution that's out there.
Ah, okay. Well, you answered my next question so let's talk about the past and future. How
have ASICs evolved over the years and how do you see them evolving in the near future?
That's an excellent question too. So the first ASIC that I worked on had 9,000 gates. And
if you take that and put it in today's 7 nanometer process, you can fit about 3,000 of those
chips on one square millimeter of silicon.
So it's phenomenal what you can do. And effectively
over the last 30 years, the ASICs have really evolved to take on more and more functionalities.
So that they can do amazing things. When you look to the future, there are really two competing
trends that interact with each other. So the first is that it's becoming more and more
expensive to do the initial startup for an ASIC. So in other words, to go through the
design process to build the masks and to get a factory provisioning up and running to build
the thing. Secondarily, however, it's also becoming increasingly easy to automatically
implement them to do large portions of the design and in an automated fashion. We've
seen some of that recently with the latest announcements on automated floor planning
and so on. So on the one hand it's becoming easier and more and more people will be able
to design ASICs, but on the other hand, the actual object is becoming more expensive.
So I think there's this tension between the two is going to resolve itself one of two
ways. Either there will be fewer ASICs because they'll be too expensive to make or there
will be more of them because the ease of design is going to supersede the cost of building
them and that somehow or other people will figure out lower cost mechanisms for building
them. And I think that's actually the one that's more likely to win that we will see
more application-specific designs as people find more and more interesting problems to
apply them to.
Well thanks so much Rob! I think we know a lot more about ASICs now than we did just
a few minutes ago. Check out all our other “What Is” episodes here and be sure to
subscribe to this channel because we’ll be adding more as the year progresses. Thanks
for listening!