New-Tech Europe Magazine | August 2016 | Digital edition

Functional Safety and what it means for System IP

hopkins, ARM Processors

Functional safety for Silicon IP used to be a niche activity, limited to an elite circle of chip and system developers in automotive, industrial, aerospace and similar markets. However over the last few years that’s changed significantly. There’s now a more tangible vision towards self-driving cars with increasingly adventurous Advanced Driver Assistance Systems (ADAS) to capture people’s interest along with media-rich in-vehicle infotainment. Moreover the emergence of drones in all shapes and sizes and the growing ubiquity of industrial Internet of Things are also proliferating the requirement for functional safety, all of which are relevant to ARM ® . Much like any technology market surrounded in ‘buzz’ these burgeoning applications require semiconductors to make them happen and the fast-pace of product innovation has attracted

huge interest from ARM’s partners. In the IP community ARM leads the way with a broad portfolio of IP from ARM Cortex ® -M0+ to the mighty Cortex-A72 and beyond. With a heritage in secure compute platforms and functional safety ARM is well placed to enable the success of its silicon partners. What’s functional safety all about? In a nut-shell, functional safety is what the name says, it’s about ensuring that products operate safely and continue to do so even when they go wrong. ISO 26262 the standard for automotive electronics defines functional safety as: ISO 26262 “the absence of unreasonable risk due to hazards caused by malfunctioning behaviour of electrical / electronics systems”. Standards for other markets such as

IEC 61508 for electrical and electronic systems and DO-254 for airborne electronic hardware have their own definitions, although more importantly they also set their own expectations for engineering developments. Hence it’s important to identify the target markets before starting development and ensure suitable processes are followed – attempts to ‘retrofit’ development processes can be costly and ineffective so best avoided. Figure 1 illustrates a variety of standards applicable to Silicon IP. In practice, functionally safe means a system that is demonstrably safe to a skilled third-party assessor, behaving predictably in the event of a fault. It must fail safe which could be with full functionality or graceful degradation such as reduced functionality or a clean shutdown followed by a reset and restart. It's important to realize

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