The expanded STM32L4 ecosystem builds on ST’s free STM32Cube platform. This comprises the STM32CubeMX initialization-code generator and configurator with power estimation for ultra-low-power design, and the STM32CubeL4 package that contains middleware components, Nucleo-32 Board-Support Package (BSP), Hardware Abstraction Layer (HAL), and Low-Layer APIs (LLAPIs). For a quick start to new projects, the slim-form-factor NUCLEO-L432KC board – the first Nucleo-32 board to integrate an MCU in the tiny QFN32 package - includes an STM32L432KCU6 device (UFQFPN32) and provides direct access to ARM mbed online tools. Its Arduino Nano pin layout simplifies function extensions, and the integrated ST-Link debugger/programmer supports mass storage and allows probe-free debugging.
Five added STM32L43x and STM32L44x MCU product lines comprise variants with versatile combinations of an integrated USB controller, an LCD controller, and cryptography. Up to 256 kByte of Flash and low-pin-count-package choices suit them for cost-sensitive applications. The added devices also rich digital peripherals including a True Random-Number Generator (TRNG) and smart analogue features such as a 12-bit, 5 Msample/sec ADC, internal voltage reference, and ultra-low-power comparators.
All devices include FlexPowerControl (FPC) with features such as separate supply-voltage domains for gating power individually to analog peripherals, USB circuits, and I/Os. Batch-Acquisition Mode (BAM) enables energy-efficient data capture and seven reduced-power modes with further sub-modes maximize energy savings in a wide range of operating conditions.
According to EEMBC ULPBench tests the STM32L433 is certified at 177 ULPMark-CP[ULPMark-CP: micro] at 3.0V, tested without the aid of a step-down converter. Aided by ST’s ART Accelerator, outright performance is also high at 273 CoreMark. In small-form-factor packages from 5 x 5 mm QFN-32 to 14 x 14 mm LQFP-100, including 3.14 x 3.13 mm WLCSP, prices start from $2.045 for the STM32L431KBU6 with 128 kByte Flash and 64 kByte SRAM in QFN-32 (10,000).