Although CAN is still commonly used in modern vehicles, FlexRay is now a popular choice for applications with strong bandwidth and safety requirements, with systems such as brake-by-wire or steer-by-wire calling for a more robust solution.

FlexRay has been designed to be deterministic, supporting asynchronous events and with much faster data rates when compared to CAN, with up to 10Mbits/s opposed to 1Mbit/s.

There are several chip manufacturers that offer microcontrollers with built-in FlexRay interfaces, such as:

●    ST SPC56xxx family,
●    FreeScale MPC56xx family,
●    TI TMS570 line of safety MCUs

Despite the obvious benefits, they are a number of things to consider before choosing FlexRay over CAN, including the expense of development and debugging tools and extended development time due to the complexity of the protocol.

We advocate careful review of all application requirements before choosing FlexRay over CAN to ensure the right choice is made.