STM32L451REI6 belongs to the family of ultra-low-power MCUs provided by STMicroelectronics. It is designed based on the high-performance Arm?Cortex?-M4 32-bit RISC core which operates at a frequency of 80 MHz. The design of low-power applications can be achieved based on a comprehensive set of power-saving modes. A full set of DSP instructions and a memory protection unit (MPU) are integrated to improve application security. Moreover, the STM32L451REI6 microcontroller is integrated with Up to 21 capacitive sensing channels, standard and advanced communication interfaces, high-speed embedded memories, a wide range of enhanced I/Os and peripherals, etc. A suite of protection mechanisms is provided for embedded Flash memory and SRAM, including readout protection, write protection, proprietary code readout protection, and Firewall.