The 38 microcontrollers in an Audi Q7 come from eight companies, highlighting the complexity of auto supply chains, according to research firm IHS Markit.
I think that must be 38 models of MCU. In a car as complex as a Q7 there should be a lot more MCUs than that. Even low end cars generally have more than 38 MCUs.
I agree. Many sensors can be digital nowadays and each have their own little microcontroller. NXP even makes Cortex-m0 (IIRC) chips that have integrated CAN transceivers. You can hook them straight up to the bus. They are small 48 pin devices, not intended for large ECU's.
How many sensors are there on a modern petrol or diesel engine again? How many cilinders does it have? (each coil may have a uC) What if you need hybrid systems? (charger, motor drive, battery, coupling to transmission systems, + more for redundancy). Mikeselectricstuff did a teardown of a headlamp unit of a BMW. Each headlight unit has a microcontroller
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38 models then starts makes sense.. it quickly adds up. I would not be surprised in a Mercedes S or Q7 class vehicle, the qty of uCs in the interior already exceeds 38.
Could there be a model like is used for software development with long-term support releases and incremental improvement releases that retain compatibility with the long term support releases?
For example, would it be possible to have it so that a microcontroller was engineered and steadily improved, but would retain compatibility with earlier models for the lifetime of a microcontroller family? More advanced microcontrollers would act like earlier models unless their special instructions or registers were invoked to unlock the new behavior. This is of course done in software, for example, 16-bit real mode on 32-bit and 64-bit Intel processors, for example.
Why can't there be generic pinouts for power converters, where some of the pins would be configured, for example grounded, for the basic model, and as improvements are made, the configurations pins would be changed to enable the new functionality. Leaving such options in hardware might be a lifesaver at some point because one could substitute a newer part for an older one.
If manufacturers are so eager to have their customers adopt newer silicon, maybe doing it this way would encourage that.
I think this is one of the major selling points of ARM eco-system; if you have coded your software algorithm to run a NXP Cortex-m4 chip, it will also work on a ST or Microchip Cortex-m4. You 'only' need to replace the board support package of your firmware, however, that is usually substantial effort, or not even possible if manufacturer A has an unique (patented) feature in their uC's. This is even less trivial for automotive or medical, which needs everything automotive certified, reviewed and commissioned..
In addition, the adoption of embedded systems is the race towards smaller designs, lower cost and often also time-to-market. A chip that has more features than necessary is excess luggage that will slow it down. Like @ataradov said; manufacturers are so occupied with low power consumption.
And then I think, that manufacturers don't like making pin compatible products of their competitors. Namely that can work both ways: you may receive clients from your competitor, but if your company performs badly then chances are that you will directly lose clients. In other words: manufacturers like cash flow and protect it. Preferably you want to keep your clients in your self-designed product prison, often referred to as "the ecosystem". Once in, it must be very hard to break out, as that ensures that the cash flow stays with you. There is no 2nd supplier. There is no drop-in replacement from vendor A or C. Can anybody explain to me how that is an ecosystem? It's not like a bird only eat 1 type of seed. Then it really sounds more like a prison to me..
In similar terms, I really don't understand how manufacturers like Wurth or Samtec can make money. I think their 'ecosystem' are the niche industrial products and/or custom tailored products, which indeed have their place in the market. However, I have also received several consultants over the years and on each occasion they were asking about volume and if we used their connectors/passives. Well.. a 1k resistor stays 1k across all manufacturers. Same for an inductor, LED, pin header, etc. Half of those parts I don't even spec a MPN for. My assembler probably has their own stock.
Going back to the power consumption race of embedded systems: I've heard of a story in which a heart rate sensor for a popular brand smartwatch was redesigned. The digital processing was based on a 8-bit microcontroller design, however, the quiescent power consumption was far too high. They redesigned the firmware and ASIC implementation of said microarchitecture. They went as far as checking which instructions were not used by the firmware and removing those from the ASIC hardware. Those extra instructions may increase switching activity (=power consumption) with 0 extra functionality added. It can then make sense to strip half the ALU if you don't need those operations. In the story I've been told this was a PIC-based microcontroller. I'm not sure where this was produced, but if it was a licensed design then chances are it is also manufactured by Microchip or on the same technology fab/node. Since this was a very high volume product, that could easily add more supply chain pressure.