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STM32L5 Microcontrollers (MCU) with Arm TrustZone Technology

STMicroelectronics has introduced the ultra-low power STM32L552 and STM32L562 microcontrollers, offering a broad range of security capabilities for OEMs to create better protected IoT-connected applications.

Operating at clock frequencies up to 110MHz, the STM32L5 series microcontrollers are based on Arm’s Cortex®-M33, a security-specialist processor core which gives MCUs the ability to implement Arm® TrustZone® hardware-based security. The TrustZone trusted computing platform creates a protected execution environment for connected products and their sensitive code such as key storage, thus blocking attempts to corrupt devices or software. A second, independent execution environment allows for the running of untrusted code.

An MCU which has TrustZone capability is already a strongly protected device, but STMicroelectronics has added the ability to include or exclude each I/O, peripheral, or area of Flash or SRAM from TrustZone protection. This allows sensitive workloads to be fully isolated for maximum security.

In addition, STMicroelectronics has built on the TrustZone capabilities to add:

  • Support for secure boot
  • Special Read and Write protection for integrated SRAM and Flash memory
  • Cryptographic acceleration in the STM32L562, including AES 128-/256-bit key hardware acceleration, public key acceleration and AES-128 on-the-fly decryption to protect external code or data

The STM32L5 MCUs also feature active tamper detection and secure firmware installation. This comprehensive set of security features and capabilities has enabled ST to gain PSA Certified Level 2 status for the STM32L552 and STM32L562.

These security capabilities are combined in the STM32L5x2 devices with ultra-low power performance to enable the MCUs to deliver high operating speed and long run-times, whether powered by coin cells or even through energy harvesting. Low-power techniques deployed in the MCUs include:

  • Adaptive voltage scaling
  • Real-time acceleration
  • Power gating
  • Multiple reduced-power operating modes
STM32L5 Features
  • Low-power performance scores:
    • 370 ULPMark-CoreProfile
    • 54 ULPMark-PeripheralProfile at 1.8V
  • 512kbyte dual-bank Flash
  • 256kbyte SRAM
  • High-speed external memory interfaces:
    • Single, dual, quad or octal SPI
    • HyperBus™ Flash or SRAM interface
    • One interface for SRAM, PSRAM, NOR, NAND or FRAM
  • USB Full-Speed interface
  • USB Type-C® and USB Power Delivery interface
  • One ADC
  • Two power-gated DACs
  • Two ultra-low power comparators
  • Two operational amplifiers
  • STM32CubeL5 one-stop-shop software package
STM32L5 Applications
  • Consumer devices
  • Industrial equipment
  • Metering
  • Health monitoring
  • Machine monitoring
  • Mobile point-of-sale terminals
STMicroelectronics — STM32L5


Development Kits


STMicroelectronics — STM32L552E-EV

The STM32L552E-EV is a complete development platform demonstrating the Arm TrustZone features and the ARMv8-M mainline security extension.



STMicroelectronics — NUCLEO-L552ZE-Q

This STM32 Nucleo-144 development board features an STM32L552ZE MCU, switch-mode power supply, and Arduino, ST Zio and morpho connectivity.



STMicroelectronics — STM32L562E-DK

The STM32L562E-DK Discovery kit makes use of the STM32L562QEI6QU’s ultra-low power features to enable prototyping for many wearable or sensor applications.


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