Apple's A Series Micro-Arch is not from ARM Holdings

By: FacePalmedToTheNthDegree (, June 26, 2019 8:34 pm
Room: Moderated Discussions
This from ArsTechnica

when referring to a recent Apple hire Mike Filippo.

"The hire is a big get for Apple. ARM is responsible for technology that powers the A series chips Apple has been using in its mobile devices. For instance, the A12X in the iPad Pro springboards off the big.LITTLE architecture from ARM."(1)

Arm Holdings is not at all responsible for the micro-architecture in Apple's A series cores as that's mostly from Apple's P.A. semiconductor acquisition CPU architects and later hires at the time starting with Apple's A7 Cyclone development cycle. And Apple's A series is a fully custom micro-architecture that's engineered to execute the ARMv8A ISA. And yet to this very day this mistake is still made by some in a rather poorly informed technology press.

How can such egregious mistakes continuously go unchallenged when ARM Holdings' reference Designs have not one thing to do with Apple's Fully Custom A series cores that have been fully custom affairs since the A7 Cyclone core hit the ground running as the first ARMv8A 64 Bit ISA capable custom micro-architecture that beat even ARM Holdings to the 64 bit market. ARM Holdings only licensed the ARMv8A ISA to Apple and more folks should take the time to go an read Anand Lal Shimpi's ARM Holdings and Apple A7 related articles to get the proper background into just what is ARM Holdings business model and what IP that Apple's fully custom ARM ISA executing cores really are based on, and that's not really related to anything ARM Holdings did other than license to Apple the ARMv8A ISA.

Big.LITTLE is more an asymmetrical CPU core pairing than a CPU architecture with each of the Big/Little groupings cores in the Big/Little parings having their own underlying implementations that execute the same ISA. So that's maybe something to credit ARM Holdings with doing but really it's rather inaccurate to state that Apple's A series CPU Micro-Architectural implementations have very much at all to do with Arm Holdings above only sharing an ability to execute the Same ARMv8A/Newer ISA.

And I really do wish that the Press in general would refer to ARM Holdings(The company) and not just ARM as that's going to be a bit confusing as well when needing to differentiate ARM the CPU/ISA designs(Reference, Semi-Custom, Fully Custom) from the company that licenses the IP. This is very confusing for any proper differentiation between the fully custom ARM micro-architectures that are only engineered to run the ARMv8A/Newer ISA and really have no other similarities to ARM Holdings Reference Design CPU cores other than the Ability to execute the ARMv8A/Newer ISA.

ARM Holdings did not create Broadcom's Vulcan micro-architecture as that was re-engineered to execute the ARMv8A ISA from it's original MIPS antecedent. And Broadcom only Licensed the ARM ISA and not any other CPU IP from ARM Holdings. Apple's A Series cores are a bit wider order superscalar than any thing that ARM Holdings has ever produced in house and Broadcomm's Vulcan supports SMT4 as well and I will not get into much about the Vulcan Core IP changing hands via IP sell offs the results of several acquisitions and buyouts to end up inside ThunderX2 and now under Marvell's IP holdings currently. Samsung's M3/M4 Mongoose core designs are not ARM Holdings' handy work as that's more the result of Samsung's engineering as a top tier ARM Holdings Architectural Licensee where ARM Holdings only provided at a price its ARMv8A ISA for licensing and not much in the way of any design help afterwards.

Really Arm Holdings did not design the A11 bionic chip's neural engine or the Monsoon cores or energy-efficient cores, called Mistral, in that A11 SOC, or any other Apple DSP/GPU IP either.

The press appears to be well able to differentiate AMD's custom x86 implementations from Intel's custom x86 implementations but to this day has difficulty comprehending any Third Party custom micro-architectural implementations that only execute the licensed from ARM Holding ISA. As far as the press is concerned for the most part is all comes from ARM Holdings when in fact it's not that way for Apple's A series cores, Samsung's M3/M4 Mongoose cores, or Broadcom/Cavium/Marvell's Vulcan(ThunderX2), and a few others, CPU micro-architectural implementations either.

Really ARM Holdings is the company that Licenses IP mostly to others and even provides some Reference Design CPU/GPU/Fabric blueprints/IP for licensing for many others who lack their own in house chip design capabilities. But ARM Holdings does have Top Tier Architectural licensees who have chip designs that easily rival any CPU/GPU designs that Arm Holdings can provide, Apple being the prime example of one and Samsung and a few others as well. Samsung will be licensing GPU IP from AMD for tablet/phone graphics based on AMD's RDNA GPU IP, and I really would like someone to ask Lisa Su what Became of their K12 custom ARM core IP, and is that licensable as well.

Apple has hired Jim Keller and all of P.A. Semiconductor via acquisition later and many other CPU/GPU engineers and they appear to be moving around the entire industry as well hired on for different projects, the same as Mike Filippo. But when is the technology Press going to vett their own or at the very least hire qualified technology editors for even the minimal amount of fact checking.


" Apple ARMs itself —
Apple bolsters its chip team by hiring architect who worked at ARM, Intel, AMD
The CPU-for-Macs rumor is bound to resurface, but nothing’s for sure still."
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TopicPosted ByDate
Apple's A Series Micro-Arch is not from ARM HoldingsFacePalmedToTheNthDegree2019/06/26 08:34 PM
  Apple's A Series Micro-Arch is not from ARM HoldingsAndrei2019/06/26 11:33 PM
    Apple's A Series Micro-Arch is not from ARM HoldingsMichael S2019/06/27 12:07 AM
      Apple's A Series Micro-Arch is not from ARM Holdingsnone2019/06/27 01:01 AM
        Apple's A Series Micro-Arch is not from ARM HoldingsMichael S2019/06/27 01:44 AM
          Apple's A Series Micro-Arch is not from ARM Holdingsnone2019/06/27 03:31 AM
      Apple's A Series Micro-Arch is not from ARM HoldingsAndrei2019/06/27 01:08 AM
        Apple's A Series Micro-Arch is not from ARM HoldingsMichael S2019/06/27 01:42 AM
          Apple's A Series Micro-Arch is not from ARM Holdingsdmcq2019/06/27 02:03 AM
          Apple's A Series Micro-Arch is not from ARM HoldingsAdrian2019/06/27 03:49 AM
            Apple's A Series Micro-Arch is not from ARM HoldingsMichael S2019/06/27 04:07 AM
              Apple's A Series Micro-Arch is not from ARM HoldingsAdrian2019/06/27 04:38 AM
    Apple's A Series Micro-Arch is not from ARM HoldingsMaynard Handley2019/06/27 07:57 AM
  Apple's A Series Micro-Arch is not from ARM Holdingsdmcq2019/06/26 11:37 PM
  What's with all the crazy rants this week? (NT)Anon2019/06/27 12:46 AM
    Probably the heatwave in Europe (NT)Foo_2019/06/27 12:20 PM
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