The MIPI Alliance has focused on developing semiconductor interface standards for the mobile industry for almost 15 years. However, the influence of mobile devices on the rest of electronics has driven MIPI technology into other markets, including automotive.

Matt Ronning and Uwe Beutnagel-Buchner, Chair and Vice Chair of the MIPI Alliance’s recently formed Automotive Birds of a Feather Group, respectively, discuss how the family of interface standards has evolved and their value proposition in next-generation automotive applications.

When discussing MIPI, “mobile” is the first market that comes to mind. What’s driving the use of MIPI technology in automotive?

RONNING: It is true that the mobile industry has driven MIPI standardizations thus far, but in general all standardized interfaces can be seen as application-independent. In the same way that mobile-type processors employ MIPI interfaces, so do automobile-type processors and sensors.

Automakers already rely on MIPI Alliance’s industry-standard interfaces to enable a wide variety of applications, including driver assistance, infotainment, and navigation. Just as mobile handset manufacturers benefited from the standardization that MIPI Alliance has provided, automotive OEMs similarly benefit.

BEUTNAGEL-BUCHNER: Today, MIPI members are leveraging their investments in mobile to think about how they can use them for automotive. OEMs are interested in the features MIPI Alliance brings to mobile devices for cars.

However, the electronics content in the more than 90 million vehicles manufactured per year worldwide is increasing due to the pressure of environmental regulations and the market pull of safety concerns. As an example, future autonomous driving systems have been projected to require as many as eight or nine image sensors.

MIPI interfaces will be used to link cameras and displays to automotive electronic control units (ECUs). Current advanced driver assistance systems (ADAS), such as collision-mitigation cameras, are expected in the future to migrate to more complex, fully autonomous driving systems. It is expected that MIPI interfaces will play a major role to link not only cameras, but also all the surrounding sensors to processing units.

Where are MIPI interfaces currently deployed in automobiles today, and, moving forward, how will they coexist with the host of other vehicle interfaces?

RONNING: MIPI interfaces such as Camera Serial Interface 2 (MIPI CSI-2), Display Serial Interface (MIPI DSI), and Display Serial Interface 2 (MIPI DSI-2) are ideal for a variety of low- and high-bandwidth applications that integrate components such as cameras, displays, biometric readers, microphones, and accelerometers.

MIPI I3C helps automotive system designers minimize the complexity, cost, and development time for products that use multiple sensors in a space-constrained form factor.

Highly sensitive, mission-critical automotive applications also benefit from MIPI interfaces’ low electromagnetic interference (EMI), a capability that’s been proven in billions of mobile phones and other handheld devices.

BEUTNAGEL-BUCHNER: The car consists of different electric/electronics systems in different domains, like drivetrain, chassis control, driver assistance, infotainment, and more. Every domain has its typical interfaces, like the well-known CAN bus for lower bandwidth functions. In the driver assistance domain, higher bandwidth data links are necessary for surround sensors, like cameras. They are based currently on Ethernet and low-voltage differential signaling (LVDS). While Ethernet is already standardized, the contribution from MIPI for such interfaces could be, for example, the standardization of LVDS-based data links.

What are the goals of the MIPI Automotive Birds of a Feather Group?

RONNING: The overall goal is to bring together the MIPI Alliance’s physical and protocol layer design experts with automotive OEMs and tier one and component suppliers to help MIPI improve upon existing interfaces or develop new ones to meet the needs of the automotive industry.

An immediate goal is to use the meetings with global OEMs and tier one suppliers to gather requirements. For example, what are the needs for interfaces in next-generation vehicles?

One result of our meetings to date is the requirement that any new interface support cable lengths up to 15 meters with 4 in-line connectors. Another immediate goal is to understand and be able to articulate the value proposition of any new interface standard and the timeline that would be acceptable for OEMs.

This will drive both the creation of new specifications and the proliferation of current ones.

Are cars today really just smartphones on wheels?

BEUTNAGEL-BUCHNER: Cars of the future are likely to have embedded wireless communications to enable them to communicate with other cars (V2V) and infrastructure such as stoplights (V2X), and so in that sense they can be viewed as smartphones on wheels.  But maybe more appropriately, these cars of the future will be viewed as supercomputers on wheels. Massive processing power will be required to accurately process and interpret the data being generated by the many cameras, radars, and other sensors created in real time.

MIPI is working on standardized interfaces that can be and are being implemented in different components like processors, ASICs or image sensors. 

More information on MIPI's Automotive Birds of a Feather group can be found at mipi.org/groups/automotive-birds-feather-group.

MIPI Alliance

mipi.org/groups/automotive-birds-feather-group

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