Driving ADAS Applications with MIPI CSI-2

By Joe Rodriguez, Product Marketing Manager, Rambus

We’re all familiar with seeing social media influencers on our mobile phones these days, but when you think about it, the real influencers are the mobile phones themselves. Over the past decade, as mobiles have evolved and pushed all sorts of technological boundaries, they have influenced other industries to follow suit. Nowhere has this influence been more obvious than in the automotive industry where cars have been getting smarter, more automated, and more connected with each new generation, powered by a remarkable number of state-of the-art technical standards.

Cars are now leveraging technology refined by the mobile industry for features such as high-resolution dashboard displays, back-up rear cameras, infotainment displays with GPS navigation, multi-wireless Bluetooth for integrating smartphones to the vehicle’s operating system, Wi-Fi and 4G/5G cellular connections and web browsers, voice recognition and voice commands, as well as important Advanced Driver Assistance Systems (ADAS), which will be the focus of this article.

Even with improvements in how information is conveyed to drivers, the fact remains that human error is the leading cause of traffic accidents. ADAS applications automate elements of the driving experience to increase safety and avoid accidents. Examples of safety-critical ADAS applications include lane departure warnings, lane keeping assist, blind spot detection, pedestrian detection, driver monitoring systems, and automatic breaking.

ADAS systems can leverage a wide variety of sensors that span the EM spectrum to create a comprehensive 3D image of the dynamic environment around the vehicle. Data from lidar (light detection and ranging), radar and traditional global shutter cameras are combined to create and update the digital twin of the world the car traverses. All this converged sensor data takes tremendous bandwidth, and the MIPI® Camera Serial Interface 2 (MIPI CSI-2®) is increasingly the workhorse solution for transporting all this mission critical sensor data to the ADAS chassis management processors.

Operating over the MIPI C-PHY℠ or D-PHY℠ physical layer, MIPI CSI-2 can support sensors with a broad range of different image resolutions, video frame rates, and color depths. This makes it ideal for handling data from the ever-growing number of sensors inside cars, each with their own function and each handling a different type of data.

The new CSI-2 v4.0, released in February 2022, added several new capabilities that can bring additional advantages and flexibility to designers architecting ADAS applications. These include Always-On Sentinel Conduit (AOSC) capabilities where ultra-low-power image sensors and video signal processors (VSPs) continuously monitor their surrounding environments and then wake their CPUs only when something significant happens, as well as RAW28 pixel encoding for high-dynamic-range automotive image sensors.

ADAS systems require high quality and high reliability IP solutions as defined by ISO 26262 Automotive Safety Integrity Level (ASIL) requirements. Rambus has been a provider of MIPI IP solutions since 2010 and offers 32 and 64-bit digital controllers for MIPI CSI-2. The Rambus CSI-2 Transmitter (Tx) Controller has received ISO-26262 functional safety certification at the ASIL-B level from SGS-TÜV, the world’s leading test, inspection, and certification company.

ASIL levels are determined through the analysis of potential functional safety hazards and their system impact including severity, detectability, and recoverability. The results of this assessment are documented in the form of a Safety Manual, Design Failure Mode & Effects Analysis (DFMEA), Failure Mode, Effects and Diagnostic Analysis (FMEDA), and other documentation. In addition, the development processes used in the creation of the Rambus CSI-2 Controllers have also been certified by SGS-TÜV to be in accordance with ISO 26262 ASIL-B.

The number of sensors inside cars is expected to continue to grow as cars become more autonomous in the future. Rambus IP solutions ensure that automotive chip makers can meet important vehicle functional safety requirements, while still benefiting from state-of-the-art performance and reduced time-to-market. For more information, visit the Rambus MIPI CSI-2 Controller product listing.