Analysis of Apple A6 core reveals exquisite, optimized custom layout done by hand

“Over the last week, more and more details of Apple’s custom A6 processor design have come to light, including a custom armv7s-compatible core design and its triple-core GPU,” Chris Foresman reports for Ars Technica.

“Detailed analysis by Chipworks and iFixit have revealed that Apple’s custom ARM core design appears to have been laid out by hand instead of by computer algorithms—a time-consuming process that can result in optimized high-frequency operation,” Foresman reports. “‘It looks like the ARM core blocks were laid out manually — as in, by hand,” iFixit’s Miroslav Djuric said via e-mail. ‘A manual layout will usually result in faster processing speeds, but it is much more expensive and time-consuming.'”

Foresman reports, “That time-consuming manual layout process would also certainly help explain why it took Apple over four years from its acquisition of fab-less design firm PA Semi to release its own custom silicon for its mobile devices. Based on our experience with the iPhone 5, the hard work is paying off in spades.”

Apple A6 processor
Apple A6 processor

Read more in the full article here.

Related articles:
Apple A6 die reveals 3-core GPU – September 21, 2012
iPhone 5′s A6 SoC SunSpider performance fastest ever recorded on a smartphone – September 19, 2012
Apple’s custom A6 processor the result of years of effort, including a $500 million chip development program – September 18, 2012
A6 is Apple’s first with custom-designed CPU cores; iPhone 5 memory size and speed revealed – September 16, 2012

24 Comments

    1. It pays off just for this chip. However, I’d imagine they’re already manually tweaking future chips for years to come. If you’re a CPU designer, that has to be a dream job!

  1. What did Steve say??? You put as much care and craftsmanship on the inside as you do on the outside, cause you care….. Remember the original Mac classic where the engineering team signed the case??? The special layout of the pc board and the interior design of the system.

    Because you care.

    Just a thought.

  2. Had to do a similar hand-layout (obviously this means during *design* phase, not actual fabrication) in a 4th-year engineering class, a decade ago. Of course it was for a primitive 8-bit counter circuit, but we had enough space left over to etch a Mac Finder face onto the surface as an easter egg 🙂

    1. The lenghths of wires (especially the clock tree) is shortened, the sizes of wires is customized to match impedences and reduce capacitive coupling with neighbouring wires. Sometimes, you even go as far as avoiding certain geometries for better current flow. Routing of power can be similarly customized to make sure brownouts are avoided during worst case scenarios.

    2. IC design is no different than PCB design. The auto-route algorithm’s used by PCB design software is soooo bad that I do my boards manually. If the auto-route algorithm’s are tweaked for improved clock, other design features are sacrificed. There is no substitute for the human mind except for mundane repetitive tasks.

      1. Amen.

        I worked many years with designing PCB boards, and the auto-route choice always seemed a poor solution. Maybe if the customer wanted very cheap prototypes.

        Of course, there are improvements being made, but in my opinion an experienced human still produces the best result. With some help from the computer of course.

  3. Not to be out done, Microsoft has partnered with the Samsung Re-Engineering Division to fabricate their ‘Whole New Approach’ chip technology, tentatively codenamed “A-Whole”….

  4. So Apple has hand-laid-out microchips?

    See, this is the kind is cheap showy marketing gloss that only Apple can pull off. Why are they still getting a free ride people?

    Apple must have known that someone half-way around the world would disassemble an iPhone 5, remove the chips, use ion beam etching to strip off the chip casing material, then use a variety of high-powered microscopes to peer into its structure.

    This is all a slick marketing stunt designed to fleece the sheeple.

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