Not content with designing the iPad itself, Apple also engineered its own processor – a peppy 1GHz powerplant dubbed the A4.
A multitouch tablet wasn’t the only new bit of kit which Apple launched today. Inside the iPad is the first processor designed by the company – and it certainly won’t be the last.
Christened the A4, it’s the work of the chip design team from PA Semi, which Apple bought for US$278 million in late 2008. That acquisition shows plenty of forethought, because only now are we seeing the results of this canny investment.
Known for designing chips with exceptionally high performance and energy efficiency, PA Semi was a ‘fabless’ chip designer – a company which draws up the blueprints for the processor but contracts the job of baking and making the silicon to a third party (unlike Intel, which produces its own processors it its own fabrication plans or ‘fabs’).
Little is known about the A4, although it’s certainly built on an ARM architecture in order to natively run iPhone apps. However, as Apple’s ARM licence permits the company to modify the architecture, the A4 is likely to have been highly customised for the iPad. And no doubt it will find its way into the fourth-gen iPhone when that touched down mid-year.
Apple has referred to the A4 as a ‘system on a chip’ or SoC part, which means the graphics, memory controller and possibly even IO are integrated into the same die as the processor core.
While Intel wants a piece of the smartphone action with its forthcoming ‘Moorestown’ SoC superchip, the rise of the A4 is yet another win for the ARM platform, which also includes Qualcomm’s 1GHz SnapDragon processor inside Google’s Nexus One.