October 19, 2011 -- ARM today announced the ARM Cortex-A7 MPCore processor, the most energy-efficient application class processor ARM has ever developed, and big.LITTLE processing, a flexible approach that redefines the traditional power and performance relationship.

The Cortex-A7 processor builds on the low-power leadership established by the Cortex-A8 processor. A single Cortex-A7 processor delivers 5X the energy-efficiency and is one-fifth the size of the Cortex-A8 processor, while providing significantly greater performance. The Cortex-A7 processor will enable a rich user experience in sub-$100 entry-level smartphones.

One of technology's most significant challenges today is how to create a system-on-chip (SOC) that meets the conflicting consumer demand for devices with both higher-performance and extended battery life. Big.LITTLE processing, enabled by Cortex-A7, achieves this by pairing the best of the high-performance Cortex-A15 MPCore and ultra-efficient Cortex-A7 processors. Big.LITTLE processing allows devices to seamlessly select the right processor for the right task, based on performance requirements. Most important, this dynamic selection is transparent to the application software or middleware running on the processors.

ARM Partners supporting these technologies include Broadcom, Compal, Freescale, HiSilicon, LG Electronics, Linaro, OK Labs, QNX, Redbend, Samsung, Sprint, ST-Ericsson and Texas Instruments.

By developing big.LITTLE processing and the Cortex-A7 processor, ARM has addressed the challenge for technology that can deliver both high-performance, required for content creation and consumption, while also delivering extreme power efficiency for extended battery life. This is particularly pertinent as smartphones and tablets continue to evolve into the primary platforms that consumers use to interact with our increasingly connected world.

Cortex-A7: Extending ARM low-power leadership

The efficiency of the ARM architecture is the reason why ARM processors use less power and occupy a smaller footprint. The Cortex-A7 processor occupies less than 0.5mm², using 28-nm process technology, and provides compelling performance in both single and multicore configurations. Used as a stand-alone processor, the Cortex-A7 will deliver sub-$100 entry-level smartphones in the 2013 to 2014 timeframe with an equivalent level of processing performance to today's $500 high-end smartphones.

Big.LITTLE processing

Big.LITTLE processing combines two different, but compatible processors within the same SOC and allows the power management software to seamlessly select the right processor, or multiple processors, for the right task. The processors appear identical from an applications software perspective.

The "LITTLE," lowest-power processor — in this case, the Cortex-A7 — runs the operating system (OS) and applications for basic always-on, always-connected tasks, such as social media and audio playback. The OS and apps can then be seamlessly migrated to the higher-performance processor as demands increase for high-end tasks, such as navigation and gaming. The time for this migration is in the order of 20µs.

The efficient and seamless switching of workloads between the two processors is supported by advanced ARM system IP, such as AMBA 4 ACE Coherency Extensions. This ensures full cache, I/O and processor-to-processor coherency between the Cortex-A15 and Cortex-A7, and across the complete system. Software and applications can, therefore. continue to run unhindered, and unnoticed by the user, as the tasks are rebalanced to provide the optimum big.LITTLE user experience.