The range has an operating frequency of up to 110MHz from the Arm Cortex-M33 32-bit RISC core with Arm TrustZone hardware-based security. Trusted computing authenticates devices connected to a network by creating a protected execution environment for cyber-protection and sensitive code (cryptography and key storage) that blocks attempts to corrupt devices or software. A second, independent, execution environment allows for the running of untrusted code.
ST has added to the trusted computing architecture by providing the freedom to include or exclude each I/O, peripheral, or area of Flash or SRAM from TrustZone protection. ST has also engineered TrustZone to ensure support for secure boot, special read-out and write protection for integrated SRAM and Flash, and cryptographic acceleration, including AES 128/256-bit key hardware acceleration, public key acceleration (PKA), and AES-128 On-The-Fly Decryption (OTFDEC), to protect external code or data. The STM32L5 supports active tamper detection and secure firmware installation. The STM32L5 family has been certified to PSA Certified Level 2.
Adaptive voltage scaling, real-time acceleration, power gating, and multiple reduced-power operating modes enable the MCUs to deliver high performance and long run-times. In addition, a highly efficient switched-mode step-down regulator can be powered up or down on-the-fly to improve low-power performance when the VDD voltage is high enough. The resulting ULPMark scores include 370 ULPMark-CoreProfile and 54 ULPMark-PeripheralProfile at 1.8V.
The STM32L5x2 MCUs feature 512 Kbyte dual-bank Flash that allows read-while-write operation and the Flash supports Error Correction Code (ECC) with diagnostics. There is also a 256Kbyte-SRAM and features to support high-speed external memory including single, dual, quad, or octal SPI and Hyperbus Flash or SRAM, and an interface for SRAM, PSRAM, NOR, NAND or FRAM.
As part of the STM32 family of MCUs, the STM32L5 series is fully supported by the STM32 ecosystem.