STMicro STM32U3 ultra-low-power Cortex-M33 MCU achieves 117 Coremark/mW in active mode, consumes 1.6 µA in stop mode

STMicro STM32U3 is a new family of Arm Cortex-M33 microcontrollers clocked at up to 96 MHz with ultra-low-power consumption designed for utility meters, healthcare devices such as glucose meters and insulin pumps, and industrial sensors.

The company says the STM32U3 MCU family is a “market leader in terms of efficiency” with 117 Coremark/mW in active mode, and consumes 1.6µA in stop mode. The Coremark/mW score means the STM32U3 offers almost twice the efficiency of the STM32U5 series, and five times that of the STM32L4 series. Other highlights include up to 1MB of dual-bank flash, 256kB of SRAM, and various interfaces like MIPI I3C, SAI audio, 12-bit ADC, etc…

STMicro STM32U3 key features and specifications:

• MCU Core
  • 32-bit Arm Cortex-M33 CPU @ 96 MHz with TrustZone and FPU
  • Performance
    • 1.5 DMIPS/MHz (Dhrystone 2.1)
    • 387 CoreMark (4.09 CoreMark/MHz)
    • 500 ULPMark-CP
    • 117 ULPMark-CM
    • 202000 SecureMark-TLS
• ART Accelerator with DSP instructions
• Memory/Storage
  • 256 KB SRAM including 64 KB with hardware parity check
  • 512KB or 1024KB dual-bank flash with ECC
  • OCTOSPI external memory interface supporting SRAM, PSRAM, NOR, NAND, and FRAM memories
  • SDMMC interface
• Peripherals
  • Up to 82x GPIOs with interrupt capability, most 5 V-tolerant, and up to 14 I/Os with independent supply down to 1.08 V
  • USB 2.0 full-speed controller
  • 1x SAI (serial audio interface)
  • Audio digital filter with sound-activity detection
  • 3x I2C FM+(1 Mbit/s), SMBus/PMBus™
  • 2x I3C (SDR), with support of I2C FM+ mode
  • 2x USARTs and 2x UARTs (SPI, ISO 7816, LIN, IrDA, modem), 1x LPUART
  • 3x SPIs (6x SPIs when including 1x with OCTOSPI + 2x with USART)
  • CAN FD controller
  • 12-channel GPDMA controller, functional in Sleep and Stop modes (up to Stop 2)
  • Up to 21x capacitive sensing channels with support for touch key, linear, and rotary touch sensors
  • Analog
    • 2× 12-bit ADC 2.5 Msps with hardware oversampling
    • 12-bit DAC module with 2 D/A converters, low-power sample and hold, autonomous in Stop 1 mode
    • 2x operational amplifiers with built-in PGA
    • 2x ultralow-power comparators
  • Up to 15x timers and 2x watchdogs
    • 1x 16-bit advanced motorcontrol
    • 3x 32bit and 3x 16bit general purpose
    • 2x 16bit basic
    • 4x lowpower 16bit timers (available in Stop mode)
    • 2x watchdogs
    • 2x SysTick timer
    • RTC with hardware calendar, alarms, and calibration
  • CRC calculation unit
• Security and cryptography
  • Arm TrustZone and securable I/Os, memories, and peripherals
  • Flexible life cycle scheme with RDP and password protected debug
  • Root of trust due to unique boot entry and secure hide protection area (HDP)
  • Secure firmware installation (SFI) from embedded root secure services (RSS)
  • Secure data storage with hardware unique key (HUK)
  • Secure firmware upgrade
  • Support of Trusted firmware for Cortex-M (TF-M)
  • 2x AES coprocessors, including one with side channel attack resistance (SCA) (SAES)
  • Public key accelerator, SCA resistant
  • Key hardware protection
  • Attestation keys
  • HASH hardware accelerator
  • True random number generator (TRNG), NIST SP800-90B compliant
  • 96-bit unique ID
  • 512-byte OTP (one-time programmable)
  • Antitamper protection
• Clocks
  • 4 to 50 MHz crystal oscillator
  • 32.768 kHz crystal oscillator for RTC (LSE)
  • Internal 16 MHz factory-trimmed RC (±1 %)
  • Internal low-power RC with frequency 32 kHz or 250 Hz (±5 %)
  • 2x internal multispeed 3 MHz to 96 MHz oscillators
  • Internal 48 MHz with clock recovery
  • Accurate MSI in PLL-mode and up to 96 MHz with 32.768 kHz, 16 MHz, or 32 MHz crystal oscillator
• Debugging – Serial-wire debug (SWD), JTAG, Embedded Trace Macrocell (ETM)
• Supply Voltage – 1.71V to 3.6V
• Power management – Embedded regulator (LDO) and SMPS step-down converter supporting switch on-the-fly and voltage scaling
• Power Consumption
  • 1.6 μA Stop 3 mode with 8-Kbyte SRAM
  • 2.2 μA Stop 3 mode with full SRAM
  • 3.8 μA Stop 2 mode with 8-Kbyte SRAM
  • 4.5 μA Stop 2 mode with full SRAM
  • 9.5 μA/MHz Run mode @ 3.3 V (While(1) SMPS step-down converter mode)
  • 13 μA/MHz Run mode @ 3.3 V/48 MHz (CoreMark SMPS step-down converter mode)
  • 16 μA/MHz Run mode @ 3.3 V/96 MHz (CoreMark SMPS step-down converter mode)
• Packages  – All ECOPACK2 compliant (RoHS+)
  • UFQFPN32 – 5 x 5 mm (Pitch: 0.5 mm)
  • FQFPN48/LQFP48 – 7 x 7 mm
  • WLCSP52 –  3.1 x 3.2 x 0.6 mm (Pitch: 0.4 mm)
  • WLCSP68 –  3.1 x 3.2 x 0.6 mm (Pitch: 0.35 mm)
  • UFBGA64/LQFP64
  • UFBGA100/LQFP100
• Temperature Range – Up to -40 °C to +105 °C

Two families are available: the STM32U375 and the STM32U385, which adds cryptography with features like a coupling and chaining bridge (CCB), HUK (Hardware Unique Key) + PKA (Public Key Accelerator), and AES-128/256 + S-AES.

STMicro also shared a Coremark/mW comparison chart showing STM32U3 on top as the most efficient MCU. However, it’s not overly useful as the list only includes unnamed Competitors A to F.
Hardware and software development tools include the STM32CubeU3 MCU Package and the NUCLEO-U385RG-Q Nucleo-64 development board with STM32U385RGT6Q microcontroller, a USB-C Type-C port with ST-LINK debugger, and Arduino and ST morpho expansion headers.

The STM32U3 series is in production and the price is starting at $1.93 for orders of 10,000 pieces. The NUCLEO-U385RG-Q development board goes for $24.11 on ST’s estore. Visit the product page and/or read the press release for additional details.

Support CNX Software! Donate via cryptocurrencies, become a Patron on Patreon, or purchase goods on Amazon or Aliexpress