New Ultra-Low Power STM32L5 Microcontrollers with Security for IoT Applications
New Microcontrollers feature an Arm® Cortex®-M33 32-bit RISC core with Arm TrustZone® hardware-based security
STMicroelectronics has released ultra-low-power STM32L5x2 microcontrollers (MCUs) that emphasize security to assure better protected IoT-connected applications.
Operating at clock frequencies to 110MHz, the STM32L5-series MCUs start from the Arm® Cortex®-M33 32-bit RISC core with Arm TrustZone® hardware-based security.
First conceived for equipment such as desktops, mobile devices, and communication infrastructure, 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.
To this foundation, ST adds the freedom to include or exclude each I/O, peripheral, or area of Flash or SRAM from TrustZone protection, allowing sensitive workloads to be fully isolated for maximum security. In addition, ST has 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 also supports active tamper detection and secure firmware installation. With this attention to security, the STM32L5 has been certified to PSA Certified Level 2.
As IoT and embedded devices increase in intelligence and functionality, security must be built in from the ground up, said Thomas Ensergueix, senior director, Automotive and IoT Line of Business at Arm. The STM32L5 series makes it easier for developers to build trusted PSA Certified devices based on the Arm Cortex-M33 processor, providing a robust and secure foundation for devices ranging from consumer products to industrial equipment.
On top of this protection and design flexibility, ST mixes in its proprietary ultra-low-power expertise through techniques like adaptive voltage scaling, real-time acceleration, power gating, and multiple reduced-power operating modes, to enable the MCUs to deliver high performance and long run-times, whether powered by coin cells or even through energy harvesting. 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, which are key measures of ultra-low-power efficiency based on real-world benchmarks developed by EEMBC, are excellent: 370 ULPMark-CoreProfile and 54 ULPMark-PeripheralProfile at 1.8V.
As a market leader in MCUs with a strategic focus in areas like Smart Cities, Smart Buildings, and Smart Industry, ST recognized the importance of a series of MCUs that combined world-class ultra-low-power consumption with industry-leading security and data protection, for mission-critical applications and at-the-edge node processing, said Ricardo De Sa Earp, Microcontroller Division General Manager, STMicroelectronics. Applying ST’s expertise in ultra-low-power design and processing technologies and adding our security and data protection on top of the solid foundation of Arm TrustZone and the outstanding STM32 ecosystem, the STM32L5x2 MCUs are ideal for Industrial IoT applications – metering, health (human or machine) monitoring, mobile point-of-sale – that require reliability and security.
The STM32L5x2 MCUs offer 512 Kbyte dual-bank Flash that allows read-while-write operation to aid device management and the Flash ensures a high level of safety by supporting 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.
Digital peripherals for the STM32L5x2 include USB Full Speed with dedicated supply, allowing customers to keep USB communication even when the system is powered at 1.8V, and a UCPD controller compliant with USB Type-C Rev. 1.2 and USB Power Delivery Rev. 3.0 specifications. Smart analog features include a state-of-the-art analog-to-digital converter (ADC), two power-gated digital-to-analog converters (DAC), two ultra-low-power comparators, and two operational amplifiers with external or internal follower routing and programmable-gain amplifier (PGA) capability.
Features of the top of the range STM32L562ZET6 include
- Arm® 32-bit Cortex®-M33 CPU with TrustZone® and FPU
- ART Accelerator
- 8-Kbyte instruction cache, frequency up to 110 MHz, MPU, 165 DMIPS and DSP instructions
- Ultra-low-power with FlexPowerControl
- 1.71 V to 3.6 V power supply
- -40 °C to 85/125 °C temperature range
- Batch acquisition mode (BAM)
- 187 nA in VBAT mode: supply for RTC and 32x32-bit backup registers
- 17 nA Shutdown mode (5 wakeup pins)
- 108 nA Standby mode (5 wakeup pins)
- 222 nA Standby mode with RTC
- 3.16 µA Stop 2 with RTC
- 106 µA/MHz Run mode (LDO mode)
- 62 µA/MHz Run mode @ 3 V (SMPS step-down converter mode)
- 5 µs wakeup from Stop mode
- Brownout reset (BOR) in all modes except Shutdown
- Up to 512-Kbyte Flash, two banks read-while-write
- 256 Kbytes of SRAM including 64 Kbytes with hardware parity check
- External memory interface supporting SRAM, PSRAM, NOR, NAND and FRAM memories
- OCTOSPI memory interface
- General-purpose inputs/outputs
- Up to 114 fast I/Os with interrupt capability most 5 V-tolerant and up to 14 I/Os with independent supply down to 1.08 V
- Performance benchmark
- 1.5 DMIPS/MHz (Drystone 2.1)
- 442 CoreMark® (4.02 CoreMark®/MHz)
- Energy benchmark
- 370 ULPMark-CP® score
- 54 ULPMark-PP® score
- 27400 SecureMark-TLS® score
- Arm® TrustZone® and securable I/Os, memories and peripherals
- Flexible life cycle scheme with RDP (readout protection)
- Root of trust thanks to unique boot entry and hide protection area (HDP)
- SFI (secure firmware installation) thanks to embedded RSS (root secure services)
- Secure firmware upgrade support with TF-M
- AES coprocessor
- Public key accelerator
- On-the-fly decryption of Octo-SPI external memories
- HASH hardware accelerator
- Active tamper and protection against temperature, voltage and frequency attacks
- True random number generator NIST SP800-90B compliant
- 96-bit unique ID
- 512-byte OTP (one-time programmable) for user data
- Power management
- Embedded regulator (LDO) with three configurable range output to supply the digital circuitry
- Embedded SMPS step-down converter
- External SMPS Support
- Clock management
- 4 to 48 MHz crystal oscillator
- 32 kHz crystal oscillator for RTC (LSE)
- Internal 16 MHz factory-trimmed RC (±1%)
- Internal low-power 32 kHz RC (±5%)
- Internal multispeed 100 kHz to 48 MHz oscillator, auto-trimmed by LSE (better than ±0.25% accuracy)
- Internal 48 MHz with clock recovery
- 3 PLLs for system clock, USB, audio, ADC
- Timers - Up to 16 timers and 2 watchdogs
- 16x timers: 2 x 16-bit advanced motor-control, 2 x 32-bit and 5 x 16-bit general purpose, 2x 16-bit basic, 3x low-power 16-bit timers (available in Stop mode), 2x watchdogs, 2x SysTick timer
- RTC with hardware calendar, alarms and calibration
- Communication - Up to 19 communication peripherals
- 1x USB Type-C™/ USB power delivery controller
- 1x USB 2.0 full-speed crystal less solution, LPM and BCD
- 2x SAIs (serial audio interface)
- 4x I²C FM+(1 Mbit/s), SMBus/PMBus™
- 6x USARTs (ISO 7816, LIN, IrDA, modem)
- 3x SPIs (7x SPIs with USART and OCTOSPI in SPI mode)
- 1x FDCAN controller
- 1x SDMMC interface
- Rich analog peripherals (independent supply)
- 2x 12-bit ADC 5 Msps, up to 16-bit with hardware oversampling, 200 µA/Msps
- 2x 12-bit DAC outputs, low-power sample and hold
- 2x operational amplifiers with built-in PGA
- 2x ultra-low-power comparators
- 4x digital filters for sigma delta modulator
- 2 DMA controllers - 14 DMA channels
- Up to 22 capacitive sensing channels - Support touch key, linear and rotary touch sensors
- CRC calculation unit
- Debug mode
- Development support: serial wire debug (SWD), JTAG, Embedded Trace Macrocell™ (ETM)
More information on the STM32L5x2 Range of Microcontrollers is available on the ST Web site
STMicroelectronics STM32L5x2 Series main page.
STM32 is a registered and/or unregistered trademark of STMicroelectronics International NV or its affiliates in the EU and/or elsewhere. In particular, STM32 is registered in the US Patent and Trademark Office.
The company's Web site address is www.st.com.
[Reprinted with kind permission from STMicroelectronics - Release Date, 13th February, 2020]