Integrated ECUs are the future
Automotive networks have developed in the last few decades by the simple addition of networking capabilities to previously mechanical or electro-mechanical modules. While this provides great new features for the vehicle, it also creates a network that is not well suited to the complex, multi-functional nature of a car. For this reason, manufacturers are creating new ECUs to operate as Domain Controllers and Zone Controllers to create a more hierarchical structure within the network. These controllers integrate multiple vehicle functions into a single box, but still require independent operation of these functions. Choosing a processor specifically designed for this environment greatly simplifies the development process and so here are seven reasons why the S32Z/E Real-Time Processors should be your choice for this application area.
1 High Performance
These processors are fast. A powerful embedded processor from just a few years ago had perhaps two cores running at 320 MHz along with a helper core at 160 MHz. The S32Z/E Processors have 8 Arm® Cortex®-R52 real-time cores running at up to 1 GHz along with three Arm® Cortex®-M33 helper cores running at 400 MHz. That is around 18 kDMIPS of real-time performance. They also add a math coprocessor for offloading DSP and ML functions for an additional 25 GFLOPS of vector mathematics.
Each device can scale the number of real-time cores from 4 to 8, by adding lockstep for improved safety capability and the operating frequency from 600 MHz to 1 GHz. As application needs vary, so does the memory required in the system, which is why the devices support industry standard LPDDR, SDHC and serial memory interfaces on top of the 19 MB internal fast SRAM. Lastly, the S32E family includes additional actuation support for those ECUs which need that feature while providing exactly the same compute architecture.
Scale the number of Cortex-R52 cores as needed
Integrated ECUs need the ability to operate multiple applications simultaneously, but they also need to be isolated from each other so that a faulty or rogue application cannot disrupt any other. The S32Z/E families are built from the ground up with isolation in mind. All masters, such as cores, DMAs, accelerators and communication masters are assigned as a specific identity in the system and all peripherals and memories have access policies (read and write) for each of these identities. Complex masters can take on more than oe identity if needed, which means real-time hypervisors are fully supported in hardware and separation of Virtual Machines does not rely solely on software. With these families the need to perform software para-virtualization is greatly reduced or avoided all together.
Example partition 1Example partition 2Example partition 3
4 Accelerators to offload non-value-added tasks
The very fast Cortex®-R52 cores have great real-time performance, but in a typical application there are many interrupt demands to the cores and these remove vital processing capability as the code execution flow is disrupted. To help keep the cores operating at maximum capacity, there are several accelerator cores and functions which can remove the overhead added by peripheral interrupts. These include a lockstep Cortex®-M33 operating as a System Manager, four dedicated peripheral DMAs which allow timers and communications peripherals to be loaded and read without processor intervention, an integrated communications engine with two lockstep Cortex®-M33 cores for CAN message handling, a central Hardware Security Engine to offload security tasks, and an ethernet controller, which has an integrated switch and a dedicated DMA capability. When used together, these features can greatly increase the effective processing capability of the main processor cores.
Like every other feature of these devices, the security subsystem is isolation aware and provides complete independence of operation for each independent partition. As well as supporting many modern security encryption standards, the HSE also behaves as root of trust for the entire system and controls booting from encrypted memory at reset, to handover to the execution of the applications.
6 Intra- and inter-device communication
The S32Z/E families support the latest 1 Gbps Ethernet standard and both the ethernet and CAN engines allow message passing from port to port without any external connectivity. In this way newly integrated applications can continue to communicate with others via the traditional bus means if needed – this means that ported applications do not need to have their communications stacks replaced if this is required. A more efficient communication path between isolated applications is also provided and allows isolated messaging using shared memory, without compromising data integrity or privacy. The families also introduce full support for the new CAN XL standard with two modules operating at 8 Mbps.
Intra and inter-device communications
Support for ASIL-D systems is another central part of the processor families. From lockstep cores to data integrity checks, such as Error Correcting Codes (ECC) throughout the system, the features are as would be expected on automotive targeted devices. However, in addition, the safety features are isolation aware and can be configured, such that the isolated applications have their own safety response in the event of a fault and even allow a partition to be reset or restarted, without affecting any other. This means that an entire ECU reset can be avoided if one application experiences a software or hardware fault from a watchdog timeout to a memory ECC error.
One more thing…
These are seven great reasons why the S32Z/E Real-Time Processors are ideal for this application space. But there is one more factor that makes them ideal for these applications and that is the development approach that they support. The application cores are now fast enough to allow modern modelling design techniques. In this paradigm, customers develop the functionality of their applications independent of final code and model the behavior of the ECU within an entire vehicle across a range of operating conditions. Once the final functionality is confirmed, the model can be translated into machine executable code which runs on the device. To ensure this development approach works effectively, NXP provides a Model-Based Design Toolbox, which operates in the design environment and supports hybrid development approaches, such as Processor-in-the-Loop (PiL)tools. By combining advanced modelling tools with real-time debug and trace support, NXP supports an advanced and highly efficient development flow to match the high performance of the devices.
The S32Z/E Real-Time Processors are specifically targeted at integrated ECU applications and there are at least seven (plus one) reasons why they should be your go-to choice when designing these nodes: high performance, flexibility, isolation, accelerators to offload non-value-added tasks, security, intra- and inter-device communication, safety and modern and model-based development flow.