STM32是以Cortex-M3为核的处理器，该例程介绍STM32下如何对系统时钟进行操作。系统时钟提供了精确的定时，如实时操作系统就是依靠这个来定时的。-Cortex-M3 based STM32-core processor for the routine introduction STM32 how to operate on the system clock. System clock provides a precise timing, such as real-time operat