FCLK为CPU核供给时钟信号，1/Fclk即为cpu时钟周期。HCLK为AHB bus peripherals供给时钟信号，AHB为advanced high-performance bus。PCLK为APB bus peripherals供给时钟信号，APB为advanced peripherals bus
FCLK为CPU核供给时钟信号，1/Fclk即为cpu时钟周期。HCLK为AHB bus peripherals供给时钟信号，AHB为advanced high-performance bus。PCLK为APB bus peripherals供给时钟信号，APB为advanced peripherals bus
