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Comment by Shikadi | Hacker News Reader

Would you mind backing up your claim? To my knowledge, ARM is one company that licenses their designs to other companies, who are free to parameterize and modify as they please.

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I think the idea is that it probably matters very little to Apple or Samsung or any other company that has an architectural license how well the ARM originated core performs because they are building their own core and ARM is basically a standard committee to them. Obviously companies that are using the actual ARM cores care about ARM's ability to perform.

There are two types of ARM licenses. One is an Architectectural license. This allows licensees to design and implement the ARM ISA. Apple and QCOM among others have Architectural licenses. They can add customizations such as # pipelines stages. This license is very expensive.

The other license is getting ARM's implementation of a CPU (ie A57, A72 etc). Customers can parametize # cores, cache size, memory width etc, but the basic architecture is fixed.

I don't know what the above comment was referring to but they are more than what you describe. I'd submit AMBA as an example of this; I've seen this tech utilised by IP for ASICs that don't actually contain any ARM processor cores themselves.

https://en.m.wikipedia.org/wiki/Advanced_Microcontroller_Bus...

Why don't companies just come up with their own designs?

First off designing a whole core architecture from scratch is a huge and very expensive undertaking. Youd need to be able to get a really big competitive advantage to make it worthwhile.

Secondly theres a large ecosystem of add on components designed work with ARM and be dropped into ARM SOCS, such as GPUs, Wifi modules, Gyroscopes, wireless modems, GPS, etc.

Thirdly there are a lot of SOC engineers very familiar with ARM. You can hire them streight from competitors, or college, including PHDs that have done research on it. Youd need to train up any new hirs from scratch on your architecture.

Finally theres a huge software development tool chain built around the established processor architectures. To support a new architecture youd also need to build a set of compiler back ends, bearing in mind the existing ones benefit from many years of tweaking and optimization.

Yes, SW is the key; especially Linux. ARM is way ahead of other embedded CPU architectures in terms of Linux support.

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