Apple iPhone 5s major components

Teardown: Apple iPhone 5s

With the arrival of the company’s revamped flagship smartphone, we ask the question: who says Apple doesn’t sell ‘technology’?

The new flagship smartphone for Apple, the iPhone 5s, marks a sea-change from hardware’s savviest salesmen. You may simply be upgrading because the time is right, but it’s clear that Apple now thinks there are consumers who are equally swayed by sheer silicon muscle.

It was the inclusion of a fingerprint sensor that made the headlines, but the big news for us comes from two other parts. Foremost is Apple’s new A7 processor, designed in-house. Then there is also a new co-processor, the M7, supplied and designed by NXP Semiconductors.

The A7 marks a number of firsts. It is the first smartphone chip built and released on ARM’s 64-bit, version 8 architecture. Higher-end products from all players have until now used the 32-bit version 7 architecture.

For the layout of the A7, according to analyst Chipworks, Apple has stuck with Samsung as its silicon manufacturer. This is despite intense rivalry (and outbreaks of legal warfare) between the two companies. Apple had been expected to move some, if not all, of its semiconductor manufacturing to Taiwan’s TSMC. It may still do so, but not yet.

If you are looking for a reason why Apple has stuck with Samsung, that largely appears to come down to its ability to offer a 28nm high k-metal gate manufacturing process where there was greater ease in porting over elements of the A6 design already made in Korea (shifting foundry can entail major redesigns of reused logic, particularly on the latest processes). A 28nm ‘shrink’ allows designers to theoretically fit up to 77 per cent more transistors in the same space as is occupied by a design run on a 32nm process (used on the A6).

In the real world, the usual increase is slightly smaller, but Apple has also increased the chip area for the A7 to 102mm2 - greater transistor density in a greater area. Beyond that, it has also implemented a customised version of the ARM architecture (most cellphone chips take off-the-shelf cores from the UK company).

Taken together, these design decisions mean that the A7 is twice as powerful as its predecessor. Yet that isn’t the end of the story, because there is then the M7 co-processor to take into account.

According to Chipworks, this has been integrated to take the load off the A7 for “collecting and processing accelerometer, gyroscope and compass data”. This shift will help reduce power consumption (although while Apple is claiming a longer battery life for the 5s, some users say that the initial release of the iOS7 operating system has caused a faster drain).

“After collecting information from the accelerometer, gyroscope, and magnetometer, the M7 performs some matrix math processing magic to produce an absolute orientation of the phone relative to the world. This data is then passed to the A7 in a neat package, probably in the form of three headings (roll, pitch and yaw),” says Chipworks.

“Using the A7 to monitor this sort of data would be mega-overkill, so the M7 was introduced to maintain a constant, low-power watch over these sensors.” The M7 itself is a derivative of NXP’s LPC1800 line of high-performance microcontrollers, based on an ARM Cortex M3 core.

Two key decisions that lie at the heart of the iPhone 5s design were taken while Steve Jobs was still CEO. These were Apple’s acquisition of its own chip design operation in Canada and also to take an architectural licence for the ARM core that allows it to modify and develop its own implementations.

Controlling the performance design was added to Apple’s control over all user-facing design aspects some time ago. Seen that way, the approach is very much like that of Jobs.

Ironically, the most outwardly ‘Jobsian’ feature in the iPhone 5s, its fingerprint sensor, is the result of an acquisition made after his sadly early death: biometrics specialist AuthenTec was bought in August 2012.

The emphasis on performance is, to be frank, Apple accepting reality. With the notable exception of China, the company has probably now wooed and won close to as many iPhone users as it can hope to get on the basis of attractive design, usability and its ecosystem of apps and content. And for them, iOS7, released alongside the new handset, is still an important enhancement.

As for China, though, that was the story of the iPhone 5c - and having hit a way-too-high price point for the country with no local carrier deal, it is currently a more problematic story for a later teardown.
In the meantime, the iPhone 5s really has raised the bar. *

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