ARM Zeroes In On Safety With CPU for AVs

ARM, the chip-design giant that dominates embedded and mobile silicon, believes safety is as important as speed and efficiency in its upcoming line-up of autonomous driving CPUs.

The Cortex-A76AE (Automotive Enhanced), ARM’s CPU architecture specifically designed for self-driving vehicles, was announced this week. It could form the foundation of many vendors’ AV and advanced-driver-assistance processors, given that some of the top automotive chipmakers already use ARM designs. And it’s the first of a family of self-driving chips due over the next few years.

ARM calls it the first AV CPU with integrated safety. Based on the Cortex-A76 processor announced earlier this year for laptops and high-end phones, the AE variant features upgrades to its microarchitecture to ensure safety, according to the company.

As the dream of driverless cars runs into the reality of accidents that have made many consumers wary of AV technology, safety has taken center stage in the emerging industry. ARM’s autonomous chip strategy plays into those concerns. Along with the Cortex-A76AE design, the company announced the ARM Safety Ready program, a collection of products across its portfolio that have undergone rigorous safety development. The upshot, ARM claims, is that chipmakers and car companies can get products safety-certified and on the road more quickly.

For the Cortex-A76AE, ARM significantly redesigned the A76 platform to add a capability called Split-Lock for added safety. Put simply, Split-Lock allows two CPU cores to operate either in lock-step (both carrying out the same task) or split mode (performing different tasks and applications).

This allows for high performance when the cores operate in lock-step, but one core can be split off and taken offline if it starts to fail. At that point, the autonomous driving system may operate in a degraded mode, which would reduce its self-driving capability but keep the vehicle safe.

The processor also includes several added features for things like memory protection and error reporting.

AV safety requires more than silicon, so ARM is combining several products under its new ARM Safety Ready program. They include the hardware design features, certified software components and tools, safety documentation and certification to the automotive safety standard ISO 26262.

Autonomous driving has shifted the automotive silicon market, once focused on inexpensive, low-power embedded chips, into high gear. AVs require much more powerful processors, some derived from data-center chips, to run neural networks that make driving decisions using artificial intelligence.

High-profile vendors such as Nvidia and Intel Mobileye are competing to supply these processors to what many expect will be a big market for AVs starting in the next several years. (Nvidia’s own Xavier system-on-chip incorporates a custom ARM processor.) Earlier this month, Japanese embedded processor company Renesas announced plans to buy Integrated Device Technologies, a mixed-signal chipmaker, for $6.7 billion in order to play in the AV market.

While the chips that result from that tie-up won’t initially compete with Intel and Nvidia CPUs, Navigant Research analyst Sam Abuelsamid said at the time, they may fill a niche of independent, redundant parts for reduced operation in failover mode – similar to the function chipmakers may be eyeing with the Cortex-A76AE with Split-Lock.

— Stephen Lawson is a freelance writer based in San Francisco. Follow him on Twitter @sdlawsonmedia.