ARM Don't Make Computer Chips - Computerphile

our partners now ship about a billion cpus uh a month or rather that's a billion chips containing cpus the graphics processors are still you know we're catching up we will do about 700 million units this year can you tell me about that where's the factory why don't you make the chips here so the factories in taiwan in austin texas and china and you know all those sorts of places so what happens is um we design so 25 years ago literally the founders of arm people like mike muller were taking a sheet of acetate and putting down tape strips on it which is where the origin of the phrase tape out comes from and they made images of uh a chip which were then photo reduced and you produce chips what we do now is we write hardware just like most people write software in a special language and then that language is compiled down to gates and gates or gates nand gates all of that sort of thing and uh via the magic of some software produced by some very clever tools companies that's all then spat out and it produces those pictures they're called masks and they cost about a million dollars two million dollars each time you press print on one of those um and then those are used as the basis of a it's really a photography process it's called photolithography but it's really printing and they print these incredibly credibly small features which are the chips you mentioned some big numbers there that who has to make that call if it's costing millions to to print these things who makes that call and says yeah let's go for it so it's broken down so a modern complex chip will contain an enormous number of components and they don't all come from arm by any means so we will supply what we call ip intellectual property so we will design sections of that chip and those are our products that's what we sell which go to our partners our partners are then the guys who are really designing those chips and they'll say i'll have this cpu i'll have this gpu i'll connect it with this i'm going to put my magic down in the corner here and some stuff around the outside and then they put it all together and they are the ones who eventually say go press print but of course there are lots of gates along the way there to us giving it to them and are saying we think it's okay or we think it's okay for limited production yeah we think it's fine you know go go for it big time so there are a number of quality uh barriers along the way which which have to be reached and one of the big thing about selling ip is not that you're designing something you're designing something that works and your partners can trust so before it ever goes near silicon we have simulated it millions and billions of times and hopefully then it means that when you actually come to build it it all works i know there are some people out there who use things like minecraft to do simulations or make logic gates and all this sort of stuff is this a bit like that but on a massive scale you're actually using the chips to to practice using new potential no let me get that right that's right we are using chips we're using computers running programs to simulate uh the function of silicon gates and the way in which we put those gates together in a timing accurate simulator fashion and then there's all various other things we do as well which is as well as simulate it logically we simulate it electrically which because we then feed in a model of what the chip is the silicon process is going to look like so our partners in the foundries those guys who actually make chips they tell us how that silicon works you feed that into another model you simulate it electrically and yeah it all comes good and that's that helps you know things like how how hot it will run and things like that i'm guessing yes so um simulating how hot it goes is actually still very hard but we do do it obviously simulate how fast it will go um is is easier um and simulate whether it uh will be correct if the answer is one or zero uh is is is is essential and we we work on the basis of that and the chips are now so complex so big and so massive that it's a progressive decomposition so we will simulate a very small blocks when you get that correct you put those blocks together you make a bigger block when you say that's correct you put those together you know and finally you get a gpu and then you put that together with a cpu and some memory and some interconnect and you simulate that and then you give that to the partner and he puts more stuff on and he simulates that and eventually if he's feeling bold he says um yeah get my checkbook out for our audience who don't know what a checkbook is that's something that old people used to spend money with so we make some ip blocks there'll be other companies making some ip blocks then you sell it to a company that is making chips and they'll have some of their own ip they put that all together they make those chips and then they sell that to an oem who makes a real consumer device like like a phone so in samsung's case they might make their own chips and sell them to their division that makes phones and then that division that makes phones might also buy chips from somebody else they might borrow chips from qualcomm say and then some of these companies don't actually physically make the chips themselves when they finally got the design sorted they then give it to a company called a foundry like tsmc taiwanese semiconductor company and they make a huge proportion of the world's chips themselves when it works this chain has got experts doing what they're really good at putting it together and making great products the foundry brings to mind people in a very hot room with big hammers and all sorts of stuff which i love the idea but would you say you're a bit like architects and you are selling plans yes absolutely so a lot of our design so when our designers get really really good they get the job title of architect and yes sometimes when you go to other countries your business card gets translated into man who builds houses but our architect in our industry means something um quite senior you know a person who is responsible for the design of a block he might have some people working for him who are actually building parts of that blog that he's responsible for that overall design and ultimately yes i think your analogy is very good it comes to a set of plans what we deliver to people is not um it's not bricks and mortar we deliver those plans to somebody who then builds that house they might buy bricks from a number of different people so there are there are only really a handful of foundries in the world uh who are making the modern silicon processes so they will choose to have them built at one of those although arm says we never make chips actually we do make a very small number of uh test chips but a big a big volume production run for us would be 500 chips that would be huge for us and that's that's like taking the testing to next level prototype yes so um we do i mean the thing about testing is um if you do it all of one kind then you're building in a whole bunch of assumptions that you might not even know you're doing so if you go down one direction i'll simulate this this this this and this and it works you go that's fine and what you really want for best confidence is right i'm going to do this but actually i'm going to do it from over here and i'll simulate it completely different way and i'll come at it with a whole bunch of different assumptions and if that still works you think we might be onto something here so we simulate um we we originally will model the design in our in a high-level language so a software model then we write the hardware and simulate the hardware and we will do that in those racks and reaction ranks of cpus we will also put it into specialist hardware emulation machines we will put it into fpgas field programmable devices and and we will also connect existing chips with a particular ip block so you know what this is like in real silicon you're just adding in this little bit over here we do that and you know it's the more forms of testing and testing with different sets of assumptions uh the more likely it is that it's all going to work for example here's the table here's the floor where which bits of the floor and which bits of this table can i see so you have to do a lot of matrix solving to

Channel: Computerphile

Views: 258,956

Keywords: computers, computerphile, computer, science, ARM, ARM Holdings, Chips, CPU, GPU, jem davies

Id: Jyp6jFCzW44

Length: 9min 9sec (549 seconds)

Published: Fri Jan 15 2016

Reddit Comments

[u/seattleandrew]

For anyone wondering about the tile grammar, UK english treats corporations as plural nouns like "Teachers do not eat apples", thus "ARM do not make Computer Chips" whereas in American english, corporations are considered singular nouns (and entities legally) and it should read as "ARM does not make computer chips."