SiFive Tapes Out First 5nm TSMC 32-bit RISC-V Chip with 7.2 Gbps HBM3

Maybe on microcontrollers, but the chip shortage is affecting all the "popcorn chips" too.

And there are a LOT of those.

How many chips per window motor driver? Solenoid locks. ABS systems. Radar. Tire pressure sensors. Temperature sensors. LCD displays. Peril-sensitive rear view mirror. Brake lights. Keyfobs. I can go on and on.

The reason why electric cars reduce the bill of materials so much over internal combustion engines is the fact that cars are already rolling computer banks. An electric car just gets rid of those silly parts required to turn plant slime into flame.

I know a typical Mercedes has roughly a hundred individual computers, not too far reached to think the average chip count could be 10 or higher per device on the can bus.

Almost everything in a car has a number of chips. Power regulations, communication buses... and in electric cars with thousands of batteries, at least one chip per battery for protection.

What? You think it's ten thousands to hundred thousand. Hundred thousand seems excessive to me.

I'm not saying that this is necessarily a correct interpretation of events (simply because I'm not qualified to make such a pronouncement), but I think the parent post tried to explain this by referencing the "bullwhip effect" [1], which is when relatively small changes in demand in one point of the supply chain lead to large systemic changes in resource allocation because the perception of the change is magnified at each upstream supplier.

[1] https://sloanreview.mit.edu/wp-content/uploads/1997/04/633ec...

They hang out at the same parties. For some reason all the car industry execs were convinced that people would buy dramatically fewer cars in 2020. Because they have a religious aversion to holding any stock they decided to shift the risk over to their suppliers, fucking said suppliers over, as the car industry normally does when they expect demand shifts. The thing that made this particular time special as opposed to business as usual is that the car execs all got it wrong, because people bought way more cars due to pandemic rather than less, due to moving out of cities and avoiding public transit. So they fucked over their suppliers a second time by demanding all those orders back.

Now, suppose you're a supplier of some sort of motor driver or power conversion chip (PMIC) in early 2020. You run 200 wafers per month through a fab running some early 2000s process. Half your yearly revenue is a customized part for a particular auto vendor. That vendor calls you up and tells you that they will not be paying you for any parts this year, and you can figure out what to do with them. You can't afford to run your production at half the revenue, so you're screwed. You call up your fab and ask if you can get out of that contract and pay a penalty for doing so, and you reduce your fab order to 100 wafers per month, so you can at least serve your other customers. The fab is annoyed but they put out an announcement that a slot is free, and another vendor making a PMIC for computer motherboards buys it, because they can use the extra capacity and expect increased demand for computers. So far so normal. One vendor screwed, but they'll manage, one fab slightly annoyed that they had to reduce throughput a tiny bit while they find a new buyer.

Then a few months later the car manufacturer calls you again and asks for their orders back, and more on top. You tell them to fuck off, because you can no longer manufacture it this year. They tell you they will pay literally anything because their production lines can't run without it because (for religious reasons) they have zero inventory buffers. So what do you do? You call up your fab and they say they can't help you, that slot is already gone. So you ask them to change which mask they use for the wafers you already have reserved, and instead of making your usual non-automotive products, you only make the customized chip for the automotive market. And then, because they screwed you over so badly, and you already lost lots of money and had to lay off staff due to the carmaker, you charge them 6x to 8x the price. All your other customers are now screwed, but you still come out barely ahead. Now, of course the customer not only asked for their old orders back, but more. So you call up all the other customers of the fab you use and ask them if they're willing to trade their fab slots for money. Some do, causing a shortage of whatever they make as well. Repeat this same story for literally every chipmaker that makes anything used by a car. This was the situation in January 2021. Then, several major fabs were destroyed (several in Texas, when the big freeze killed the air pumps keeping the cleanrooms sterile, and the water pipes in the walls of the buildings burst and contaminated other facilities, and one in Japan due to a fire) making the already bad problem worse. So there are several mechanisms that make part availability poor here:

1. The part you want is used in cars. Car manufacturers have locked in the following year or so of production, and "any amount extra you can make in that time" for a multiple of the normal price. Either you can't get the parts at all or you'll be paying a massive premium.

2. The part you want is not used in cars, but is made by someone who makes other parts on the same process that are used in cars. Your part has been deprioritized and will not be manufactured for months. Meanwhile stock runs out and those who hold any stock massively raise prices.

3. The part you want is not used in cars, and the manufacturer doesn't supply the car industry, but uses a process used by someone who does. Car IC suppliers have bought out their fab slots, so the part will not be manufactured for months.

4. The part you want is not used in cars, and doesn't share a process with parts that are. However, it's on the BOM of a popular product that uses such parts, and the manufacturer has seen what the market looks like and is stocking up for months ahead. Distributor inventory is therefore zero and new stock gets snapped up as soon as it shows up because a single missing part means you can't produce your product.

and this is how a conference call among car industry exec buddies that have convinced each other that for some reason people will buy fewer cars in a pandemic managed to destroy the entire electronics market for (hopefully no more than) a year or so

The only difference between a shuttle run and mass production is whether your chip is repeated 100 times in different parts of the wafer (surrounded by other people's chips) or a few thousand times completely covering the wafer with copies of just your chip.

The manufacturing process is identical either way.

Interesting fact, the term tape out comes from the way chips were physically laid out back in the early days. The chip layout was manually arranged using pieces of coloured tape on a large workspace/table. Once complete, this was photographed a layer at a time, which was then optically reduced to create the mask sets for manufacture. We still use the term tape out today, but no tape involved. I would love to have an experience of designing back during those days, it's so hands on.

a "tape out" is the process of transforming a design into a physical die - i.e. a manufacturing run. It's when you hand over a design to a foundry to do their thing with it.

Front-end is HDLs — (System)Verilog, VHDL, etc. Implementation and formal will be Jasper & its ilk. Backend (physical, etc.) use fab-specific bespoke software from the majors (Cadence, NXP, MG, Synopsis, ...).

The front-end stuff could be done by one person; Verilator is a great example (although it's now "in house" to NXP). Implementation, LEC, etc. are mathematically intimidating -- they're proof engines -- but doable by a small team.

Physical requires inside knowledge of the fabs. The fabs aren't going to let you participate unless you're a major, because it costs them a lot of money, and each additional participant is another potential leak of their critical IP.

The tooling is all "vertical" and starts on the backend. If you can't do backend, you're not a player.

The commercial tools are indeed very expensive but the required data files can be as much of a problem. Normally you have to sign a bunch of NDAs (non disclosure agreements) to get your hands on the design rules and standard cell libraries supplied by the foundries and required to make the tools work.

One effort to organize several previously available open source tools into a practical system is OpenLane, which is based on the DARPA OpenRoad project:

https://woset-workshop.github.io/PDFs/2020/a21.pdf

Recently, Google has financed a project where a foundry has made its data files available without any NDAs:

https://github.com/google/skywater-pdk

The combination has made it possible to have completely open source chip designs.

SiFive is in the business of selling IP cores and back-end implementation services. The gold standard for IP core validation is "silicon proven" i.e. that it's not just a nice theoretical design on paper, but someone has actually turned it into a physical chip and tested the real life performance.

Lots of people will try to sell you their designs and services. Picking the wrong ones can waste millions of dollars and months/years of time.

The money spent on this a prototype buys SiFive credibility for both aspects of their business (assuming the chip works) - "we were able to do this for ourselves, so you know we'll be able to do it for you".

So it's not a waste, it's a marketing expense, and a necessary one.

The article mentions that is is from the OpenFive division of SiFive. OpenFive used to be Open Silicon and their business model was working with other companies to take their Verilog RTL and do all of the physical design (synthesis to logic gates, place and route of the standard cells, timing analysis, test vector generation) and then work with the foundries to deliver all of the data for manufacturing.

Since Open Silicon is now OpenFive and part of SiFive they literally have all this experience in house and don't need to depend on another company between them and TSMC.

https://en.wikipedia.org/wiki/Open-Silicon

High voltage MOSFETs and IGBTs are built on a completely different process. Size is definitely not an issue with them. It is about exotic doping to create the desired characteristics.

They're built using much larger feature sizes but on completely separate lines.

You're right. Definitely a "hot" wafer for the engineering samples.

It is kind of ironic that compiler theory has advanced and now we can target Itanium no problem. It was a bit (well, a lot) ahead of its time.

When I have worked at large companies we handled everything ourselves and dealt directly with the fabs.

When I worked at startups and smaller companies we have interacted with:

Global Unichip Corporation (I believe TSMC owns part of the company)

https://www.guc-asic.com/en-global

Open Silicon (they literally merged with SiFive to become OpenFive and made this chip in the article)

https://en.wikipedia.org/wiki/Open-Silicon

Uniquify

https://www.uniquify.com/

Socionext

https://www.socionext.com/en/

There are others but these are the 4 that I have dealt with.

Yes.