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Why Carmakers Can’t Transition to Newer Chips

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Re: Why Carmakers Can’t Transition to Newer Chips

#51

Post by csours »

Disclaimer up front: I work for GM. I don't work on chips or components for my day job. What follows is solely my own opinion.

Some things to emphasize:

OEMs (GM, Ford, Toyota, VW, etc) do not design components, and they do not want to. They design specifications for components, and then get suppliers to bid. This is great for efficiency in established ecosystems, not great for agility.

To my knowledge, GM did not cancel any chip orders, because GM itself had no chip orders (this is oversimplified). The suppliers cancelled chip orders.

For a 1st tier supplier to move to a different process/chip would also be difficult, because they do the same thing the OEM does - supply a specification, and get 2nd/3rd tier suppliers to bid on it.

A wholesale migration to a modern architecture is risky and costly.

Smaller process/feature size on a wafer is believed to be less resilient, for example to heat and vibration.

The risk to large automakers is that something goes wrong and they have to do a recall. The risk to up and comers (Tesla) is failure to grow. Also, Tesla has a small product line and absolute loads of cash.

If you were going to design a new car electrical architecture from scratch today, you would have something like a 40-60V system with a centralized controller (or pair of controllers in a safety redundant configuration).

Even with a largely cleansheet design, Tesla uses 12V because of the sheer ubiquity of 12V components.

Re: Why Carmakers Can’t Transition to Newer Chips

#52

Post by im_down_w_otp »

clairity wrote: post #45
echelon wrote: post #31

Earlier quoted context omitted.

Why did car companies allow themselves to make such a strategic mistake? Shouldn't they be on a standard microcontroller architecture? Why not even use ARM, X86, etc? It'd save them money at this point. And there wouldn't be a supply risk.

i'd guess adding an abstraction layer (between a general purpose microcontroller and the custom interfaces it needs to support) is likely not worth the added complexity (and bugs), since cars are on development cycles of many years anyway (for the benefit of simpler software development, and the risk reduction of being able to swap out the microcontroller if need be).

They actually theoretically have a thing for this already. It's called AUTOSAR (now AUTOSAR Classic). It's supposed to be a component architecture to write down the software against a framework that can be backed by different MCUs. Of course, in practice much of the underlying esoteria of any given MCU/board configuration bled up through the abstractions and/or produced custom extensions.

Re: Why Carmakers Can’t Transition to Newer Chips

#53

Post by 01100011 »

shiftpgdn wrote: post #38
01100011 wrote: post #29

Earlier quoted context omitted.

As far as I can tell, Tesla plays fast and loose, treating their product like a manufacturer of consumer electronics and not a manufacturer of a dangerous and durable good. That obviously allows them to out-compete other auto manufacturers who are more aware of things like product liability. See the Toyota accelerator-gate lawsuits. From https://en.wikipedia.org/wiki/2009%E2%80%932011_Toyota_vehic... : > However, on…

Toyota accelerator-gate is largely a farce. Almost all of the people involved with Toyota unintended acceleration were over the age of 65 and had the poorly designed loose floor mats in their cars. Even if they had perfect readable John Carmack tier coding they still would have lost.

Sure but that's not related to the point I'm making. The point is that not following software design best practices can leave you open to liability, or at least put you in such a weak legal position that you are compelled to settle.

If/when Tesla gets hauled into court over its software flaws, any lack of adherence to best practices will make the company appear negligent.

Re: Why Carmakers Can’t Transition to Newer Chips

#54

Post by Espressosaurus »

LennyWhiteJr wrote: post #21
schiffern wrote: post #7

> “We were able to substitute alternative chips, and then write the firmware in a matter of weeks,” Musk said. “It’s not just a matter of swapping out a chip; you also have to rewrite the software.” https://www.theverge.com/2021/7/26/22595060/tesla-chip-short...

To elaborate on this, the feature sets on these low level microcontrollers are no standardized. There is no common API for them to implement. Even chips coming from the same manufacturer will have different hardware capabilities, and although low-level drivers can abstract that way to a certain extent, there will always be differences. The biggest challenge is when you need to update your firmware to use a microcontr…

Even a single hardware iteration intended to be a drop-in replacement in some cases won't be due to relying on implementation-defined behavior that is not guaranteed by the datasheet and wasn't considered a constraint by the people designing the silicon. Sometimes it's a bug, sometimes it's just "didn't think that was important".

Either way, you're left with something where the saturation behavior changed, or it's no longer possible to read out a value without risk of corruption since they assumed it can be treated as write-only, or some other hard to find and debug problem.

Swapping out chips is an exercise in testing and risk management, and never should be done without care, even before we start talking about safety critical applications.

Re: Why Carmakers Can’t Transition to Newer Chips

#55

Post by baybal2 »

dharmab wrote: post #50
baybal2 wrote: post #34

Earlier quoted context omitted.

It is very troubling development when doing something so trivial even requires a computer. That's a matter readily solved by a PID controller made of a few dozen 74XXX parts. Possibly made n-times redundant. Even a more fancy LP solver probably wouldn't need a fully fledged computer.

ECUs are simpler to build than the mechanical components they replaced and do things impossible to do mechanically (given the space and weight limits of a car). Jadon Cammisa has a great series on this stuff. Here's just one episode on one topic, drive by wire throttle control: https://youtu.be/gKsCHx5NOMM

Most drive by wire systems I seen are nothing, but a simplest closed loop PIDs.

It's very close to what you are taught in the "How to write a PID controller" class without much extra creativity.

Re: Why Carmakers Can’t Transition to Newer Chips

#56

Post by sircastor »

anaganisk wrote: post #2

When a Power PC is perfectly capable for a MARS rover missions, I dont see any reason why they must run Snapdragons. Unless some evil company, starts ditching physical controls or starts shoving Ads into Speedometer. And everyone follows. Im thankful that automobile tech didn’t discover electron yet. Imagine your speedometer consuming 200mb of ram.

Speaking from experience, I can tell you automakers are already shipping vehicles that some Infotainment apps are web technologies. Not electron, but a similar system to run an encapsulated web page.

I’m doubtful of the cluster being run by a browser engine though.

Re: Why Carmakers Can’t Transition to Newer Chips

#57

Post by baybal2 »

SkyPuncher wrote: post #43
baybal2 wrote: post #34

Earlier quoted context omitted.

It is very troubling development when doing something so trivial even requires a computer. That's a matter readily solved by a PID controller made of a few dozen 74XXX parts. Possibly made n-times redundant. Even a more fancy LP solver probably wouldn't need a fully fledged computer.

It's really easy to over react because of the silicone shortage, but in many cars these chips are replacing physically manufactured parts or significantly increasing efficiency in a way that isn't possible with physical based components. Electronic fuel injection is a _great_ example. Much of modern fuel efficiency stems from the fact that an engine can accurately control fuel in the cylinder based on a bunch of fact…

I think you are misunderstanding me.

What I mean under a computer is a Turing complete machine. A circuit just doing some LP solving, or PID is not necessarily a computer.

Re: Why Carmakers Can’t Transition to Newer Chips

#58

Post by rectang »

01100011 wrote: post #29
schiffern wrote: post #7

> “We were able to substitute alternative chips, and then write the firmware in a matter of weeks,” Musk said. “It’s not just a matter of swapping out a chip; you also have to rewrite the software.” https://www.theverge.com/2021/7/26/22595060/tesla-chip-short...

As far as I can tell, Tesla plays fast and loose, treating their product like a manufacturer of consumer electronics and not a manufacturer of a dangerous and durable good. That obviously allows them to out-compete other auto manufacturers who are more aware of things like product liability. See the Toyota accelerator-gate lawsuits. From https://en.wikipedia.org/wiki/2009%E2%80%932011_Toyota_vehic... : > However, on…

From earlier discussions here (https://news.ycombinator.com/item?id=9643551 "10,000 global variables"), Toyota's conservative, arguably antiquated approach to software architecture wouldn't necessarily prove reliable as that software evolves.

Trying to assess whether thousands of global variables are still playing nice during a major rewrite to accommodate a new chip would be definitely be difficult and time consuming!

Not that a fast-and-loose approach is ideal, either.

Writing reliable software in the context of an organization is hard.

Re: Why Carmakers Can’t Transition to Newer Chips

#59

Post by RealityVoid »

im_down_w_otp wrote: post #52
clairity wrote: post #45

Earlier quoted context omitted.

i'd guess adding an abstraction layer (between a general purpose microcontroller and the custom interfaces it needs to support) is likely not worth the added complexity (and bugs), since cars are on development cycles of many years anyway (for the benefit of simpler software development, and the risk reduction of being able to swap out the microcontroller if need be).

They actually theoretically have a thing for this already. It's called AUTOSAR (now AUTOSAR Classic). It's supposed to be a component architecture to write down the software against a framework that can be backed by different MCUs. Of course, in practice much of the underlying esoteria of any given MCU/board configuration bled up through the abstractions and/or produced custom extensions.

And AUTOSAR is a nightmare of a framework where it's nigh impossible to understand what is going on because of the crazy abstractions.

Re: Why Carmakers Can’t Transition to Newer Chips

#60

Post by dharmab »

baybal2 wrote: post #55
dharmab wrote: post #50

Earlier quoted context omitted.

ECUs are simpler to build than the mechanical components they replaced and do things impossible to do mechanically (given the space and weight limits of a car). Jadon Cammisa has a great series on this stuff. Here's just one episode on one topic, drive by wire throttle control: https://youtu.be/gKsCHx5NOMM

Most drive by wire systems I seen are nothing, but a simplest closed loop PIDs. It's very close to what you are taught in the "How to write a PID controller" class without much extra creativity.

Have you looked at any vehicle from the past 3-5 years? I own one with drive by wire and you can feel and hear it reacting to variables when you push it to the limits (either in inclement terrain or on a closed course). The linked video has specific video examples from production vehicles as well.
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