If SoftBank starts any funny business, Apple can easily switch architectures thanks to proper planning and the versatility of Darwin. My bet would be MIPS.
Adding the word architecture changes nothing. The ISA license only includes specification to ARM ISA...
If you believe that the architecture "changes nothing" then you need to ask yourself why the initialism is ISA, not IS. It's ARM's architecture that is valuable to Apple et al. when designing their own chips, but don't disregard ARM's efforts in creating the architecture.
Sorry, but you are wrong here (as is your comment above about ARM licensing reference designs).
ISA is instruction set architecture, in Apples case ARMv8 (which they license from ARM).
Micro-architecture is the actual silicon that implements the ISA. In the case of ARM, processor cores like the A53 or A57 would be considered the micro-architecture. In Apples case the A7, A8 and A9 are their own, 100% CUSTOM DESIGNED micro-architectures that are compatible with and can run the ARMv8 ISA. Apple doesn't pay ARM for access to their micro-architecture designs as they make their own.
Processors like the Exynos 7420 (which uses A53/A57 cores from ARM) actually WOULD be using ARM reference designs. In this case, Samsung would need an architecture license to use those core designs, NOT an architecture license for ARMv8 ISA. However, the Exynos 8890 uses Samsungs first custom designed core, where they would pay ARM for a license to use the ARMv8 ISA, but would NOT need to pay for a license to any ARM cores (like the new A72).
The hardest part, by far, is designing the micro-architecture. And in this area, Apple has far exceeded anything ARM has done (witness the absolute thrashing Apple cores do when put up against ARM cores). Apples micro-architecture is more similar to an Intel desktop core than any ARM core.
If you believe that the architecture "changes nothing" then you need to ask yourself why the initialism is ISA, not IS. It's ARM's architecture that is valuable to Apple et al. when designing their own chips, but don't disregard ARM's efforts in creating the architecture.
Sorry, but you are wrong here (as is your comment above about ARM licensing reference designs).
ISA is instruction set architecture, in Apples case ARMv8 (which they license from ARM).
Micro-architecture is the actual silicon that implements the ISA. In the case of ARM, processor cores like the A53 or A57 would be considered the micro-architecture. In Apples case the A7, A8 and A9 are their own, 100% CUSTOM DESIGNED micro-architectures that are compatible with and can run the ARMv8 ISA. Apple doesn't pay ARM for access to their micro-architecture designs as they make their own.
Processors like the Exynos 7420 (which uses A53/A57 cores from ARM) actually WOULD be using ARM reference designs. In this case, Samsung would need an architecture license to use those core designs, NOT an architecture license for ARMv8 ISA. However, the Exynos 8890 uses Samsungs first custom designed core, where they would pay ARM for a license to use the ARMv8 ISA, but would NOT need to pay for a license to any ARM cores (like the new A72).
The hardest part, by far, is designing the micro-architecture. And in this area, Apple has far exceeded anything ARM has done (witness the absolute thrashing Apple cores do when put up against ARM cores). Apples micro-architecture is more similar to an Intel desktop core than any ARM core.
Sorry, but you are wrong here (as is your comment above about ARM licensing reference designs).
ISA is instruction set architecture, in Apples case ARMv8 (which they license from ARM).
Micro-architecture is the actual silicon that implements the ISA. In the case of ARM, processor cores like the A53 or A57 would be considered the micro-architecture. In Apples case the A7, A8 and A9 are their own, 100% CUSTOM DESIGNED micro-architectures that are compatible with and can run the ARMv8 ISA. Apple doesn't pay ARM for access to their micro-architecture designs as they make their own.
Processors like the Exynos 7420 (which uses A53/A57 cores from ARM) actually WOULD be using ARM reference designs. In this case, Samsung would need an architecture license to use those core designs, NOT an architecture license for ARMv8 ISA. However, the Exynos 8890 uses Samsungs first custom designed core, where they would pay ARM for a license to use the ARMv8 ISA, but would NOT need to pay for a license to any ARM cores (like the new A72).
The hardest part, by far, is designing the micro-architecture. And in this area, Apple has far exceeded anything ARM has done (witness the absolute thrashing Apple cores do when put up against ARM cores). Apples micro-architecture is more similar to an Intel desktop core than any ARM core.
Comments
Sorry, but you are wrong here (as is your comment above about ARM licensing reference designs).
ISA is instruction set architecture, in Apples case ARMv8 (which they license from ARM).
Micro-architecture is the actual silicon that implements the ISA. In the case of ARM, processor cores like the A53 or A57 would be considered the micro-architecture. In Apples case the A7, A8 and A9 are their own, 100% CUSTOM DESIGNED micro-architectures that are compatible with and can run the ARMv8 ISA. Apple doesn't pay ARM for access to their micro-architecture designs as they make their own.
Processors like the Exynos 7420 (which uses A53/A57 cores from ARM) actually WOULD be using ARM reference designs. In this case, Samsung would need an architecture license to use those core designs, NOT an architecture license for ARMv8 ISA. However, the Exynos 8890 uses Samsungs first custom designed core, where they would pay ARM for a license to use the ARMv8 ISA, but would NOT need to pay for a license to any ARM cores (like the new A72).
The hardest part, by far, is designing the micro-architecture. And in this area, Apple has far exceeded anything ARM has done (witness the absolute thrashing Apple cores do when put up against ARM cores). Apples micro-architecture is more similar to an Intel desktop core than any ARM core.
https://en.wikipedia.org/wiki/Jim_Keller_(engineer)
Now at Tesla.