The STM32L412xx devices are ultra-low-power microcontrollers based on the high-performance Arm® Cortex®-M4 32-bit RISC core operating at a frequency of up to 80 MHz. The Cortex-M4 core features a Floating point unit (FPU) single precision that supports all Arm® single-precision data-processing instructions and data types. It also implements a full set of DSP instructions and a memory protection unit (MPU) which enhances application security.
- 开发板资源介绍
The STM32L412xx devices embed high-speed memories (Flash memory up to 128 Kbyte,40 Kbyte of SRAM), a Quad SPI 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.
- BSP 快速上手
The STM32L412xx devices embed several protection mechanisms for embedded Flash memory and SRAM: readout protection, write protection, proprietary code readout protection and Firewall.
- 进阶使用方法
The devices offer two fast 12-bit ADC (5 Msps), two comparators, one operational amplifier, a low-power RTC, one general-purpose 32-bit timer, one 16-bit PWM timer dedicated to motor control, four general-purpose 16-bit timers, and two 16-bit low-power timers.
In addition, up to 12 capacitive sensing channels are available.
They also feature standard and advanced communication interfaces, namely three I2Cs, two SPIs, three USARTs and one Low-Power UART, one USB full-speed device crystal less.
The STM32L412xx operates in the -40 to +85 °C (+105 °C junction) and -40 to +125 °C (+130 °C junction) temperature ranges from a 1.71 to 3.6 V VDD power supply when using internal LDO regulator and a 1.00 to 1.32V VDD12 power supply when using external SMPS supply. A comprehensive set of power-saving modes makes possible the design of low-power applications.
## 开发板介绍
Some independent power supplies are supported: analog independent supply input for ADC, OPAMP and comparator. A VBAT input makes it possible to backup the RTC and backup registers. Dedicated VDD12 power supplies can be used to bypass the internal LDO regulator when connected to an external SMPS.
The STM32L412xx family offers six packages from 32 to 64-pin packages.
- Core: Arm® 32-bit Cortex®-M4 CPU with FPU, Adaptive real-time accelerator (ART Accelerator™) allowing 0-wait-state execution from Flash memory, frequency up to 80 MHz, MPU, 100DMIPS and DSP instructions
下载程序成功之后，系统会自动运行，观察开发板上 LED 的运行效果，红色 LD1 和 LD2 常亮、黄色色 LD3 会周期性闪烁。
| [STM32_Nucleo-64_BSP_Introduction](../docs/STM32_Nucleo-64_BSP_Introduction.md) | How to run RT-Thread on STM32 Nucleo-64 boards (**Must-Read**) |
| [STM32L412RB ST Official Website](https://www.st.com/en/microcontrollers-microprocessors/stm32l412rb.html#documentation) | STM32L412RB datasheet and other resources |
USB 虚拟 COM 端口默认连接串口 2，在终端工具里打开相应的串口（115200-8-1-N），复位设备后，可以看到 RT-Thread 的输出信息:
