Huawei is the world's largest communications company and rising star in the smartphone business where it third behind Apple and Samsung.
ARM doesn't make chips itself but licenses the instruction set architectures (ISAs) and processor cores that are fundamental to much of the world's embedded applications including a near-monopoly in smartphones.
The BBC reports the memo as stating that ARM's designs include technology of US origin. The report gives this as the reason ARM has decided to comply with the US ban. ARM is headquartered in Cambridge, England, owned by SoftBank of Japan. It has had offices in San Jose and an engineering center in Austin, Texas for many years.
ARM is the UK's most successful technology company but was bought by SoftBank in 2016.
The BBC quoted an ARM statement as saying the company was "complying with all of the latest regulations set forth by the US government."
The same report quotes Huawei as saying: "We value our close relationships with our partners, but recognise the pressure some of them are under, as a result of politically-motivated decisions."
Ironically ARM sacrificed its licensing position in China when it allowed a joint venture to take over that role and then moved to being a minority shareholder in that joint venture (see SoftBank confirms sell-off of ARM China stake). As a result it could be that Huawei now receives its ARM license from and pays ARM royalties to a China-based entity.
However, it seems clear that without the direct cooperation of ARM in the western hemisphere and the extended ecosystem of EDA firms and foundries such as TSMC, Huawei would be hamstrung in terms of long-term competiton. This might drive Huawei and China generally to focus even faster on home-grown technology.
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