ARM introduces energy-efficient Cortex-A35 64-bit design

This is achieved with ARM TrustZone technology, now available as a feature within the latest ARMv8-M architecture being launched today at ARM TechCon 2015.

ARM says thst the A35 is “the most efficient Cortex-A class CPU ever designed by ARM”.

Such enhancements can deliver performance gains of up to 40 per cent over the Cortex-A7 in a best-case scenario, though the Cortex-A35’s real ambition is to deliver a complete 64-bit experience in a processor created to be a “performance-per-milliwatt leader”.

Ian Smythe, director of marketing programs at ARM’s CPU Group, said in a press briefing that the Cortex-A35 is an ultra-power-efficient 64-bit processor that is targeted at entry-level smartphones. The ARM Cortex-A57 (as used in the Snapdragon 810, Exynos 7420 chipsets) is a high performance core. ARM license these designs to many other businesses such as Apple, MediaTek, HiSilicon, Samsung, NVIDIA and Qualcomm, who either use the stock reference design (such as the ARM Cortex-A7, Cortex-A53, Cortex-A72) or redesign the core for their own custom chip (the Apple A-range, Qualcomm’s Krait and Kyro cores).

ARM expects its partners to start shipping Cortex-A35 chipsets in late 2016 so it will be a while. The application core uses the ARMv8 instruction set and is a full 64-bit core, unlike the A5 and A7, which are older ARMv7 32-bit units. “You have different implementations from us and others that proliferate it into the market”. The biggest takeaway is that ARM is targeting a much broader market for its technology. Little configurations for high-end smartphones. Big. Little assigns more powerful cores to tasks like video playback, and smaller cores for jobs like email, which extends battery life. The 64bit capable core is said to consume less than 90mW when running at 1GHz on a 28nm device. Where before the Cortex-A7 or Cortex-A5 would have been enough for most smartphone makers and end users. However, there is demand for more choices around everything from price to power efficiency to cost, and ARM and OEMs need to address that demand.