3 ms·

> Apple has wisely focused on designing its silicon (for its system on a chips, Apple uses reference designs from Arm Holdings Plc). I was under the impression

by ENOTTY 9y ago

> Apple has wisely focused on designing its silicon (for its system on a chips, Apple uses reference designs from Arm Holdings Plc). I was under the impression that the current A cores are not reference designs from ARM... That it was a purely Apple-designed core implementing the ARM ISA. Am I mistaken or is the article mistaken?

JoachimS 9y ago
Apple is one of very few companies that has an ISA license. This allows them to implement the ARM ISAs using their own microarchitecture and physical implementation. Digital was afaik the first ISA licensee, which allowed them to design the StrongARM. https://en.wikipedia.org/wiki/StrongARM https://en.wikipedia.org/wiki/StrongARM StrongARM ended up at Intel when they bought Digital. The design team for StrongARM split up into two companies: SiByte and Alchemy. The design work i in SV on StrongARM was lead by Daniel W. Dobberpuhl. Daniel was cofounder of SiByte and (more relevant) founder of PA-Semi. https://en.wikipedia.org/wiki/Daniel_W._Dobberpuhl https://en.wikipedia.org/wiki/Daniel_W._Dobberpuhl https://en.wikipedia.org/wiki/P.A._Semi https://en.wikipedia.org/wiki/P.A._Semi PA-Semi was a fabless company that designed really powerful and power efficient CPU cores based on the Power (PA) architecture. PA-Semi was really good at both architecture, but also physical design for low power. PA-Semi was acquired by Apple in 2008 (as mentioned in the article. Boutique chip maker is an interesting phrase btw). PA-Semi basically became the processor design team at Apple. Looking at the timeline, the first A-series CPU (A4) was released in 2010 which would be possible for the PA-Semi team to have developed. (If my understanding of the history is correct.)
- deleted 9y ago
  [deleted]
- dfox 9y ago
  Small correction: Intel didn't buy Digital, but got StrongARM with it's design team (and IIRC some tangentially related products like 21152) as part of settlement of some kind of patent dispute. Also of note is that Success of HTC is to some extent also coming from DEC and it's StrongARM reference platforms (mainly Itsy) which Compaq then commercialized as iPaq which was manufactured by HTC (with pressumably HTC-designed "HTC ASIC" which contained most of the various PDA-specific glue required for StrongARM).
  - B1FF_PSUVM 9y ago
    > Intel didn't buy Digital Compaq did. Rose to glory as an IBM PC clone maker, had enough cash to buy busted out DEC, dwindled away in turn to be purchased by HP, if memory serves. Sic transit.

by ENOTTY 9y ago

JoachimS 9y ago

Apple is one of very few companies that has an ISA license. This allows them to implement the ARM ISAs using their own microarchitecture and physical implementation. Digital was afaik the first ISA licensee, which allowed them to design the StrongARM. https://en.wikipedia.org/wiki/StrongARM https://en.wikipedia.org/wiki/StrongARM StrongARM ended up at Intel when they bought Digital. The design team for StrongARM split up into two companies: SiByte and Alchemy. The design work i in SV on StrongARM was lead by Daniel W. Dobberpuhl. Daniel was cofounder of SiByte and (more relevant) founder of PA-Semi. https://en.wikipedia.org/wiki/Daniel_W._Dobberpuhl https://en.wikipedia.org/wiki/Daniel_W._Dobberpuhl https://en.wikipedia.org/wiki/P.A._Semi https://en.wikipedia.org/wiki/P.A._Semi PA-Semi was a fabless company that designed really powerful and power efficient CPU cores based on the Power (PA) architecture. PA-Semi was really good at both architecture, but also physical design for low power. PA-Semi was acquired by Apple in 2008 (as mentioned in the article. Boutique chip maker is an interesting phrase btw). PA-Semi basically became the processor design team at Apple. Looking at the timeline, the first A-series CPU (A4) was released in 2010 which would be possible for the PA-Semi team to have developed. (If my understanding of the history is correct.)

deleted 9y ago
[deleted]
dfox 9y ago
Small correction: Intel didn't buy Digital, but got StrongARM with it's design team (and IIRC some tangentially related products like 21152) as part of settlement of some kind of patent dispute. Also of note is that Success of HTC is to some extent also coming from DEC and it's StrongARM reference platforms (mainly Itsy) which Compaq then commercialized as iPaq which was manufactured by HTC (with pressumably HTC-designed "HTC ASIC" which contained most of the various PDA-specific glue required for StrongARM).
- B1FF_PSUVM 9y ago
  > Intel didn't buy Digital Compaq did. Rose to glory as an IBM PC clone maker, had enough cash to buy busted out DEC, dwindled away in turn to be purchased by HP, if memory serves. Sic transit.