Apple’s A4 chip: Patent applications suggest secrets in the silicon

“In technical circles, one part of the iPad buzz has been its microprocessor, the A4, with a lack of detail from Apple (AAPL) fueling speculation about what it can or can’t do,” Erik Sherman writes for BNET.

“Unlike most of its other products, Apple went with a custom semiconductor design,” Sherman writes. “The prevailing opinion says that the chip is nothing special.”

Sherman writes, “However, it looks as though Apple has released some details — through a number of patent applications — and that there is something interesting going on in the silicon.”

• 2220100042900 — Write Failure Handling of MLC NAND
• 2220100042817 — SHIFT-IN-RIGHT INSTRUCTIONS FOR PROCESSING VECTORS
• 2220100049951 — RUNNING-AND, RUNNING-OR, RUNNING-XOR, AND RUNNING-MULTIPLY INSTRUCTIONS FOR PROCESSING VECTORS
• 2220100049950 — RUNNING-SUM INSTRUCTIONS FOR PROCESSING VECTORS
• 2220100042818 — COPY-PROPAGATE, PROPAGATE-POST, AND PROPAGATE-PRIOR INSTRUCTIONS FOR PROCESSING VECTORS
• 2220100042807 — INCREMENT-PROPAGATE AND DECREMENT-PROPAGATE INSTRUCTIONS FOR PROCESSING VECTORS
• 2220100042815 — METHOD AND APPARATUS FOR EXECUTING PROGRAM CODE
• 2220100042816 — BREAK, PRE-BREAK, AND REMAINING INSTRUCTIONS FOR PROCESSING VECTORS
• 2220100042789 — CHECK-HAZARD INSTRUCTIONS FOR PROCESSING VECTORS

Sherman writes, “All deal with microprocessor architecture details, suggesting that, unlike the speculation, Apple has used customization of the processor design to optimize performance, either on the A4 or in a future chip.”

Much more in the full article here.

33 Comments

  1. The me too box makers will not be able to drop the iPad OS into their Windows knockoff. If the OS or an app doesn’t see the A4 chip, it will not run!

  2. I have no idea at all what I am looking at. I’m glad, actually. Then I would know how these things work and then my brain would be too big and all my hats wouldn’t fit.
    Can someone explain, or at least translate?
    Thanks.

  3. This seems to indicate that they may have leveraged their experience with particularly the AltiVec optimizations in Mac OS X to accelerate iPhone OS X as well.

    One of the advantages of the PowerPC versions made by PA Semi was their spectacular power efficiency while processing large amounts of complex data – it would stand to reason that their AltiVec experiences could have been put to use as well.

    This could also be related to some of the OpenCL concepts (while probably not leading to a full implementation).

    Interesting…

    MDN word: blood — as in blood on iPad’s anti-stain glass touchscreen… ” width=”19″ height=”19″ alt=”wink” style=”border:0;” />

  4. @Swing Geezer
    It seems that Apple has found a way to implement DLP, which is a parallel-processing strategy that does not require multiple cores but has traditionally had major problems. What this artcle is suggesting is that these patents may mean that code (ie. an app) that runs on this chip has a good chance of running faster, and not breaking simply because DLP is being used. If it didn’t run faster, it would still work, and the developer could update the code to allow it to take advantage of DLP.

  5. I say shenanigans on those who think there is nothing special on that chip. Naysayers at best and fools at worse. There is truly secret sauce flowing through it.

  6. Ugh. I pity the fool who be writin’ trash about the A4. They don’t know nuthin’ ’bout it, but dat don’t stop ’em from shootin’ their big piehole off anyway. I feel like bustin’ one of them punks up. Ugh.

  7. You know, I had that feeling when I looked at the ARS article, while I didn’t know enough about current low power/embedded CPU design (so I couldn’t fault his logic or assumptions) Something just didn’t seem right (that it was just a cut down off the shelf arm cpu (and not even the most current…
    What didn’t make sense was that from a complete users point of view Apple delivered the goods! The thing (iPad) was driving a large screen (lots of pixels to light & render) and was wicked fast while barely sipping power.
    You can tech talk out your ass all day (and Stokes did that in spades) but when it comes down to REAL performance (you know for things we users actually want to do) the iPad blows everything on the market away by a huge margin; in performance, size, weight & battery life.
    So I guess Jon (ARS) what I am saying is while I can’t dispute your claims (that it is nothing special), the performance of the iPad.. does.

  8. @ MacRick,

    UNIX in general is very, very Vector driven. The Mac OS X GUI is very vector graphics heavy. Windows by contrast is all Raster based. If you’ve never seen Windows Direct X Crash taking the Windows GIU Graphics engine with it you’ve missed one the funniest, fuglist, sight in the tech industry, which is Windows not knowing now to properly refresh and redraw the screen.
    (Think Modern Artist after being clubbed about the head and face by a 35 stone police officer for 40 hours straight).

  9. @ the stoners

    “…a 35 stone police officer…”

    On the internet, everyone knows you are a savvy user aware of the metric, imperial and other measuring systems… except for for Americans, they will think you are British.

    Now for the 40 hours, well that’s the same in decimal time, so they guy might be from France. That’s Freedom for you yanks by the way, seeing as you don’t have it anymore.

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