Freescale tailors MCU for Ethernet-based vehicle applications

June 13, 2011 // By Christoph Hammerschmidt
In the run-up to its annual Technology Forum event, Freescale semiconductor has announced a new microcontroller family aiming at automotive applications. Featuring Ethernet connectivity and video compression, the MPC5604E is intended to make parking assistant systems more affordable.

In next-generation automotive environments, data traffic over internal data bus systems will significantly increase. In the discussion about future data bus architectures for in-vehicle use, chip maker Freescale bets on Ethernet - at least in specific application segments such as driver assistant systems that make use of image-processing. "We bring Ethernet into the driving car", said Stephan Lehman, Director Global Automotive Marketing for Freescale.

The statement referred to the fact that in the current vehicle generation Ethernet is used exclusively for diagnosis purposes when the car is in the workshop. Freescale however plans to use the non-deterministic Ethernet system in moving vehicles - in application fields hitherto not claimed by competing network architectures such as MOST or FlexRay. According to Lehman, Freescale plans to employ Ethernet in the first place to transport compressed video signals from the camera to driver assistant systems which process these data. Examples could be parking assistant systems which generate a top-view image based on data provided by several rear-, front- and side view cameras. In such applications, bandwidth would be an important factor, but the network system does not necessarily need to show a deterministic behavior. Thus, Lehmann expects a "largely standard 10/100 Mbit/s Ethernet without real-time abilities" for this type of application. The only modification to the standard protocol is that the application adds hardware-based AVB compliant time stamping.

In other automotive applications, Ethernet could complement and over time displace the MOST technology, Lehmann said. Ethernet as a well established industry-standard technology could offer significant cost benefits over MOST with its costly licence fees. "Theoretically, Ethernet could even be used as backbone technology", he said, "but this is certainly many years away."

In order to give designers of image-processing driver assistance systems a processor powerful enough for this kind of application, Freescale has designed another member of its Qorivva MCU family which is based on Freescale's 32-bit Power architecture. Sitting next to multiple cameras