STMicroelectronics Enters the Zone

STMicroelectronics’ new SR6P7x and SR6P6x automotive SoCs aggregate low-level ECUs into domains or zones. With a novel choice of nonvolatile memory for code, the company has a strong focus on deterministic real-time performance.

Bryon Moyer

STMicroelectronics’ new automotive SoCs enable real-time zonal or domain control in electric and hybrid vehicles. Targeting ASIL D drivetrain systems, the Stellar P-series engages directly with local sensors and actuators. It features a novel nonvolatile memory (NVM) duplicated for reliable over-the-air (OTA) updates. Just announced is the SR6P6x (P6) line, which is a subset of the earlier SR6P7x (P7) SoC.

The P7 combines five dual-core-lockstep (DCLS) CPUs (or four DCLS ones and two independent ones), clocking at up to 400MHz, with supporting lockstep cores that handle acceleration, safety, and security. Although it implements many automotive communication protocols, its emphasis is Ethernet and the new CAN XL standard. The P6 is sampling now; it and the P7, along with accompanying Stellar E chips for power conversion and Stellar G chips for body-domain zonal controllers, are expected to appear in vehicles for sale in late 2023. The P7 is scheduled to sample 1Q23.

The design implements hardware virtualization, which separates processes that share a CPU. High-voltage analog I/Os enable direct connections to drivetrain sensors and actuators. A cryptographic engine ensures the bus-traffic authenticity; a safety block monitors activity and handles operational faults.

ST chose phase-change memory (PCM) for nonvolatile storage in its Stellar SoCs rather than embedded flash memory. PCM has superior read time as well as byte- and bit-level write capability; it’s also manufacturable in 28nm and finer processes. The company’s PCM specifically targets automotive systems. The P7 provides up to 20MB of PCM for code; it duplicates the block so customers can install update code while the system executes current code.