Posted on October 28, 2013 at 10:53I work with STM32F103RBT6. In stm32f10x.h i set  #define STM32F10X_MD, it leads us to : #define SYSCLK_FREQ_72MHz 72000000 in system_stm32f10x.h. So SystemInit() function should go to SetSysClockTo72(). However on ...