stm32 systick的默认时钟是多少

Posted 2023-05-03

参考技术A 默认时钟是系统时钟，比如你倍频到72M，时钟源就是72M而不是它的8分频

STM32的系统默认时钟是多少

就是芯片最大时钟，看datasheet，APB1和APB2不一样，一般就是72MHz或36MHz。望采纳！！！ 参考技术A 如果你没有做配置，系统默认时钟频率是72MHz的。
system_stm32f10x.c文件中有定义。
#define SYSCLK_FREQ_72MHz 72000000 参考技术B AHB (HCLK) 时钟 =SYSCLK=72MHz
APB2(PCLK2)时钟=AHB 1/2时钟=36MHz
APB1(PCLK1)时钟=AHB时钟=72MHz
ADC时钟 =PCLK2 1/4= 9MHz
PLL时钟 = HSE*9=72MHz 参考技术C /*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f10x_xx.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f10x.c file
*/
然后你再去看看 SystemInit()这个函数是怎么配置的吧。看完再说。这个是标准库里面的例程主函数里的第一句话。