Independent security enabled by implementing Arm TrustZone design
Acquired PSA Level 2 with active tamper detection and security firmware

STMicroelectronics has introduced the ultra-low-power STM32L5x2 MCUs with an emphasis on security to protect IoT connected applications.
STM32L5x2 MCUs feature device management via 512 Kbytes of dual-bank Flash with read-while-write capability. This Flash provides high reliability with Error Correction Code (ECC) support. Equipped with 256 Kbytes of SRAM, they also support high-speed external memories such as single, dual, quad, or octal SPI and Hyperbus Flash or SRAM, as well as interfaces for SRAM, PSRAM, NOR, NAND, and FRAM.

Peripherals include USB Full Speed with dedicated power supply, which allows USB communication to be maintained even when the system power is 1.8V. The UCPD controller complies with the USB Type C Rev 1.2 and USB Power Delivery (PD) Rev 3.0 specifications.

Smart analog features include a state-of-the-art ADC, two power-gated DACs, two ultra-low-power comparators, and two operational amplifiers with external or internal follower routing and PGA functionality.

The STM32L5 series MCUs feature an integrated Arm Cortex M33 32-bit RISC core, operating at clock frequencies up to 110MHz and featuring Arm TrustZone hardware-based security. Designed for desktops, mobile devices, and communications infrastructure, Trusted Computing creates a secure execution environment for cyber protection and sensitive code (encryption and key storage), authenticating networked devices and preventing attempts to compromise the device or software.

Based on this, ST maximizes security by completely isolating sensitive workloads by freely including or excluding each I/O, peripheral, flash or SRAM area in the TrustZone protection function.

In addition, it is designed with AES 128/256-bit key hardware acceleration, PKA (Public Key Acceleration), AES 128 OTFDEC (On The Fly Decryption) to protect external code or data, as well as secure boot, special read and write protection for integrated SRAM and flash, and TrustZone to support cryptographic acceleration.

The STM32L5 has achieved PSA certification Level 2, supporting active tamper detection and secure firmware installation. The STM32L5 series is supported by the ecosystem and has its own one-stop software package, STM32CubeL5.

It includes hardware abstraction layer, low-level drivers, FreeRTOS, Trusted Firmware-M (TF M), secure boot and secure firmware update, USB PD device drivers, MbedTLS and MbedCrypto, FatFS file system, and touch sensing drivers.

It also supports over 300 examples that run on the STM32L552E EV evaluation board, STM32L562E DK Discovery Kit, and NUCLEO L552ZE Q. These examples can be compiled with Arm Keil development tools and the IAR or STM32CubeIDE toolchain, and are delivered with STM32CubeMIX configuration files for easy customization or code updates.