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.
These devices embed high-speed memories (2 Mbytes of Flash memory and 640 Kbytes of SRAM), a flexible external memory controller (FSMC) for static memories (for devices with packages of 100 pins and more), two OctoSPI Flash memories interface (available on all packages) and an extensive range of enhanced I/Os and peripherals connected to two APB buses, two AHB buses and a 32-bit multi-AHB bus matrix.
The STM32L4Rxxx devices embed several protection mechanisms for embedded Flash memory and SRAM: readout protection, write protection, proprietary code readout protection and a firewall.
These devices offer a fast 12-bit ADC (5 Msps), two comparators, two operational amplifiers, two DAC channels, an internal voltage reference buffer, a low-power RTC, two general-purpose 32-bit timer, two 16-bit PWM timers dedicated to motor control, seven general-purpose 16-bit timers, and two 16-bit low-power timers. The devices support four digital filters for external sigma delta modulators (DFSDM). In addition, up to 24 capacitive sensing channels are available.

Features
- Ultra-low-power with FlexPowerControl
- Core: Arm® 32-bit Cortex®-M4 CPU with FPU
- RTC with HW calendar, alarms and calibration
- Up to 24 capacitive sensing channels: support touchkey, linear and rotary touch sensors
- Advanced graphics features
- Up to 136 fast I/Os, most 5 V-tolerant, up to 14 I/Os with independent supply down to 1.08 V
- 4x digital filters for sigma delta modulator
- Rich analog peripherals (independent supply)
- 20x communication interfaces
- 14-channel DMA controller
- True random number generator
- CRC calculation unit, 96-bit unique ID
Target applications
- IoT
Benefits
- Ultra-low-power excellence
- Superior graphic capabilities
- Advanced performance
Block diagram