on this code:
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);
gpio.GPIO_Pin = GPIO_Pin_0;
gpio.GPIO_Speed = GPIO_Speed_2MHz;
gpio.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_Init(GPIOA , &gpio);
GPIOA->BSRR = GPIO_Pin_0;
GPIOA->BSRR = (GPIO_Pin_0<<16);
when there is SystemInit (); , it work corrctly.
and when i delete the SystemInit (); when the system clock not set , but the led blink and time is more then 300 ms , i dont know why the clock isnt set , but the led blink ??
i write RCC_LSICmd ( DISABLE) ; to disable internal clock , but this CMD doesnt work , and the led still blink.
i want to understand how does the clock or RCC work in stm32 , for this , i try to test these ways.And i want to set the RCC myself.