"SystemCoreClock" is undefined

k2680

参考库文件中的：
#if defined(STM32F40_41xxx)
  uint32_t SystemCoreClock = 168000000;
#endif /* STM32F40_41xxx */

#if defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F446xx) || defined(STM32F469_479xx)
  uint32_t SystemCoreClock = 180000000;
#endif /* STM32F427_437x || STM32F429_439xx || STM32F446xx || STM32F469_479xx */

#if defined(STM32F401xx)
  uint32_t SystemCoreClock = 84000000;
#endif /* STM32F401xx */

#if defined(STM32F410xx) || defined(STM32F411xE) || defined(STM32F412xG) || defined(STM32F413_423xx)
  uint32_t SystemCoreClock = 100000000;
#endif /* STM32F410xx || STM32F401xE || STM32F412xG || STM32F413_423xx */
不知道你是否define了。