New Project---Register edition

Currently the most popular way to learn STM32 is to use the firmware library!! (temporarily using Register version)

The role of the Systeminit function is to turn the external crystal through a phase-locked loop to make the system clock 180MHZ. (implemented in the firmware repository version).

The Systeminit function can be implemented in the Main.c file, but there is no function body; if we do not implement this function, that is, the system clock is set to 180MHZ, then how does the system clock come? stm32f429 Series if the external crystal oscillator (25MHZ) is not vibrating or not configured, it will use the internal HSI as the system clock for 16MHZ. It doesn't make sense to be too low on a system project!!!!!!!!!

STARTUP_STM32F429_439XX.S is the boot code.

Stm32f4xx.h the code used to store the register mappings.

. AXF and. Hex are executable files that are used to download to the Development Board!

1, register version of the establishment of the project

Only need to add the Startup_stm32f429_439xx.s file, and stm32f4xx.h (this file can be empty), and then create a main.c file, implement the main function, and introduce stm32f4xx.h header file, you can compile successfully.

The clock is off for each peripheral when power is on by default! Controlled by RCC!!

New Project---Register edition