Here I learn stm32.
cmsis folder contains code that do not use SPL or HAL.
There is only my code (and CMSIS), that I wrote with datasheets and
with a glance at SPL's code. Also, there is my_utility.h that contains
useful (for me) functions. A goal of this folder to use only CMSIS, datasheet
and registers.
spl folder contains code that use SPL. Here I learn to use SPL and how to use it.
notes.md contains algorighms to how use periphery.