The STM32L4R5xx, STM32L4R7xx and STM32L4R9xx devices are an ultra-low-power microcontrollers family (STM32L4+ Series) based on the high-performance Arm® Cortex®-M4 32-bit RISC core. They operate at a frequency of up to 120 Mhz. The Cortex-M4 core features a single-precision floating-point unit (FPU), which supports all the Arm® single-precision data-processing instructions and all the data types. The Cortex-M4 core also implements a full set of DSP (digital signal processing) instructions and a memory protection unit (MPU) which enhances the application’s security.

Ultra-low-power with FlexPowerControl
5 μs wakeup from Stop mode
Brownout reset (BOR) in all modes except shutdown
Interconnect matrix
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
RTC with HW calendar, alarms and calibration