STM32知识点1

1、时钟

HSE_VALUE：8000000
SystemCoreClock：168000000
PLL_M：8
PLL_N：336
PLL_P：2
PLL_Q：7

printf("
* SystemCoreClock:%d MHz", SystemCoreClock);
printf("
* SYSCLK :%d MHz PLLCLK = HSE_VALUE/M*N/P", HSE_VALUE/pll_m*pll_n/pll_p/1000000);
printf("
* USBCLK :%d MHz    HSE_VALUE/M*N/Q", HSE_VALUE/pll_m*pll_n/pll_q/1000000);
printf("
* AHB:HCLK :%d MHz    SYSCLK/1", SystemCoreClock/1/1000000);
printf("
* APB2_peri:PCLK2 :%d MHz    HCLK/2 ", SystemCoreClock/1/2/1000000);
printf("
* APB1_peri:PCLK1 :%d MHz    HCLK/4 ", SystemCoreClock/1/4/1000000);
printf("
* APB2_timer:PCLK2 :%d MHz    HCLK/2*2 (TIM1/8/9/10/11)", SystemCoreClock/1/2/1000000*2);
printf("
* APB1_timer:PCLK1 :%d MHz    HCLK/4*2 (TIM2/3/4/5/6/7/12/13/14)", SystemCoreClock/1/4/1000000*2);
printf("
* 32位定时器:TIM2/5");