In computer science, “real-time” describes operations that respond to events and must be completed within a specified time window. Otherwise, an application may not work properly.
Real-time applications need to work consistently and predictably, which is why they are called “deterministic.” A real-time automotive processor maintains secure, deterministic operation like an automotive microcontroller, but can offer the combination of gigahertz speed, multi-application isolation, and memory expansion capabilities more typical of microprocessors.
New real-time processors
On that front, NXP Semiconductors expanded its S32 Automotive Platform by adding a new class of real-time processors that provide the critical deterministic behavior of secure microcontrollers, as well as gigahertz speed, multi-application isolation, and memory expansion. For example, the new 16nm S32Z and S32E real-time processor families are well matched for the secure integration of software-defined vehicles.
To meet timing constraints, a processor core must provide fast interrupt responses and provide deterministic execution, which is a good match for the Arm Cortex-R52 processor cores used in the S32Z and S32E families. The cores also support functional security and hypervisors required for these secure, real-time applications.
The NXP S32Z processors are designed for security processing and domain and zonal control. They can integrate applications such as vehicle dynamics and chassis control.
The software-compatible S32E processors offer extra complex timers and 3.3/5V analog-to-digital converters (ADCs) and 5-VI/O, making them suitable for electric vehicles (EV) and smart control applications .
Hardware to Software
The S32Z and S32E processors are designed to support the transition from a hardware-centric approach of adding new functionality with boxes or electronic control units (ECUs) to a software-defined approach with “virtual ECUs” running as software tasks on a single, multicore real-time processor. Therefore, the S32Z and S32E processors can support the new software-defined vehicle requirements.
The first S32Z2 and S32E2 series currently being sampled will feature eight Cortex-R52 processor cores with split-lock support operating at up to 1 GHz. The split-lock capability allows different processor core configurations to be selected at startup, depending on the application needs. For example, there is support for four lockstep pairs, two lockstep pairs with four non-lockstep processor cores, or all eight processor cores running in non-lockstep for maximum flexibility.
The 16nm S32Z2 processors combine real-time and DSP/ML (machine learning) processing with hardware virtualization, scalable non-volatile memory, flexible memory expansion support, and network acceleration.
The processors are developed according to processes certified to ISO/SAE 21434 for cybersecurity and ISO 26262 for ASIL D functional security. They are software compatible with the S32E2 processors aimed at EV control and smart activation applications.
S32Z2 processors are enabled with NXP’s GreenVIP vehicle integration platform software and the GreenBox 3 development platform. GreenBox 3 is a development platform for S32Z2/E2 real-time processors, integrating processing, peripherals, networking and connectivity interfaces.
The GreenBox 3 development platform supports the integration of real-time applications such as vehicle dynamics, battery and energy management, motor inverter control and power conversion for central, domain and zonal architectures in new vehicle architectures and software-defined vehicles.
Memory functions and support
NXP’s S32Z and S32E processors isolate independent real-time applications with core-to-pin hardware virtualization and resource firewalls for freedom from interference. The processors are available with up to 64MB of integrated flash memory for large, zero-downtime over-the-air (OTA) updates. They also support LPDDR4 DRAM and flash expansion memory with an execute-in-place mode for large applications and AUTOSAR adaptive applications.
A communications accelerator (FlexLLCE) supporting 24 CAN interfaces, along with a Gigabit Ethernet switch supporting Time Sensitive Networks (TSN), delivers vehicle data seamlessly to the virtual ECUs to improve efficiency and streamline software development.
The S32E processors add smart activation capabilities, particularly in the form of advanced timers and high-resolution ADCs and 5-VI/Os, for EV integration applications with direct-drive motor control.
The speed of the processors up to 1 GHz exceeds that of today’s secure 28 nm microcontrollers, which typically run in the 300 to 400 MHz range. This allows the S32Z and S32E processors to support more complex real-time applications and higher levels of software integration that require higher performance.
Their ability to accelerate up to 24 CAN 2.0 and CAN FD interfaces also benefits from being able to process CAN traffic deterministically and efficiently without interrupting the processor cores.
Hardware virtualization meets the demands of new architecture
The automotive industry’s move to domain and zonal architectures is attractive to automakers, allowing them to optimize wiring harnesses, reduce costs and weight, and implement a more scalable and cost-effective, software-centric approach to developing and updating intelligent vehicles. This transformation requires processors that provide higher performance, application isolation and memory expansion capabilities to support software-defined vehicles.
These processors allow engineers to provide the isolation and freedom from interference between the virtual ECUs as provided by individual ECUs through the aforementioned core-to-pin hardware virtualization.
End-to-end virtualization support ensures that each virtual ECU has access and control only to specific processing, peripherals, memory and I/Os to ensure isolation and support independent fault responses that do not affect other virtual ECUs. In addition, the hardware virtualization supports defined quality of service levels related to external memory access.
NXP provides system support for S32Z and S32E processors to accelerate a range of designs. These include the co-developed FS86 ASIL D security system base chip (SBC) and PF5030 power management IC (PMIC) with in-vehicle network support plus Ethernet switches and PHYs and CAN transceivers, along with other analog companion chips such as the GD3160 IGBT/SiC high voltage inverter gate driver and MC3377x battery cell controllers.
NXP’s S32Z280 and S32E288, the first two devices in the new families, are now being tested. The company plans to test the S32Z1 series a little further down the road. The real-time processors will also be scaling up with 5-nm products in the future. In fact, NXP has already developed a functional 5-nm real-time processor test chip.