STM32 F4 Clock Sources

#include <stm32f4xx.h>
#include "mcu_config.h"

int main(void)
{                    
   GPIO_config(); // Initializing and clocking PA.8

   RCC_MCO1Config(RCC_MCO1Source_HSI,    RCC_MCO1Div_1);
// RCC_MCO1Config(RCC_MCO1Source_HSE,    RCC_MCO1Div_1);
// RCC_MCO1Config(RCC_MCO1Source_PLLCLK, RCC_MCO1Div_1);

 while(1)
 { 
 } 
}