Renesas Locks Onto ECU Design With Virtualization Solution

April 29, 2022 by Abdulwaliy Oyekunle

Renesas’ latest electronic control unit (ECU) virtualization platform takes on incorporating robust automotive micro-controllers for vehicle motion and zone control applications.

From deploying the airbag during a crash to enabling a keyless ignition system, vehicles perform many essential functions thanks to the small but complex computers integrated into a module called an ECU

With high-performance components integrated into a unit, the ECU in a vehicle performs different functions ranging from power steering control, emergency braking, vehicle body control, etc.


Examples of the different electronic systems in a vehicle. Image used courtesy of Chip Estimate


As manufacturers push forward innovation to provide more advanced functions in next-gen vehicles, Renesas has released a robust automotive virtualization platform to meet the growing demands of putting several ECU functions in a single chip.

Before discussing the new solution from Renesas, let’s first have an insight into what manufacturers put in place when fabricating ECUs.


Some Design Considerations for ECUs

Overall, ECUs integrate both hardware and software components to perform their functions. The development of an ECU is based on the V-model and follows industry standards such as the ISO 26262.

The essential components employed by designers for an ECU include microcontrollers (MCUs), analog-to-digital converters (ADCs), sensors, and actuators. Above all, the microcontroller is particularly used to provide efficient and robust performance for automotive functions. What's more, ECUs that control the start of a vehicle's engine feature starter torque that is evaluated in real-time to get the instant start time of the engine.

During the development of an ECU, designers follow an iterative process of testing and verifying the hardware and software components, which is done to detect possible failure modes that cause the breakdown of the whole system or inhibit a seamless experience when driving the vehicle.  


The Need for Zone Architecture for ECUs

As certain architectures, like the distributed automotive architecture, can't meet the requirements of next-gen vehicles, attention is shifting towards having a centralized architecture in which numerous functions are incorporated into a single ECU.


Schematic of power distribution module in zone architecture.

Schematic of power distribution module in zone architecture. Image used courtesy of Texas Instruments


The centralized structure called the zone architecture promises to address the demands for high computing performance. For instance, the zone architecture comprises a vehicle compute module with a large processing capacity to execute all complex computations irrespective of function.

In the zone architecture, designers and engineers utilize organized ECUs to optimize power consumption by employing a power distribution module that efficiently distributes power to different loads and ECUs in the vehicle.

In addition, the zone architecture promises to provide higher fuel efficiency for internal combustion engine-based vehicles. Designers, however, have to surmount the challenges associated with interference between concurrent applications for safety and security.


Renesas' MCU-based Zone ECU Solution  

Aiming to push ECU and zone architectures further, the collaboration between ETAS and Renesas has yielded the development of a virtualization platform that incorporates RH850/U2x microcontrollers and an RTA-HVR hypervisor

The platform promises to provide a ready-made environment with pre-configured embedded software for zone ECU designs. The platform allows the integration of multiple applications into a single ECU.


Block diagram of RH850/U2B microcontroller.

Block diagram of RH850/U2B microcontroller. Image used courtesy of Renesas


Thanks to the RTA-HVR hypervisor, designers could convert one physical ECU to multiple virtual ECUs. What's more, the hypervisor from ETAS utilizes the hardware virtualization features of the RH850/U2x family to create multiple virtual machines. Each virtual machine has one or more virtual central processing unit (CPU) cores, a section of memory space, and a set of peripherals.

On the other hand, the RH850/U2x microcontrollers feature a RISC-V-based multiple instruction, multiple data (MIMD) high-performance embedded processor, hypervisor hardware support, and safety functions. 

Employing the microcontrollers in the solution could enable freedom from interference and deliver a high-performance NoC (Network-on-Chip) structure. This structure claims to guarantee the real-time behavior of the individual integrated applications.

Engineers could take advantage of the pre-built ready-to-use solution to reduce the development cost and risk associated with zone ECU designs. 

Speaking on the solution, Senior Director, Automotive Digital Products Marketing Division at Renesas, Satoshi Yoshida, asserted that the new ECU Virtualization Solution Platform could give users the advantage of easy, fast development of advanced systems with built-in safety and security features.