/* Initialize the boards on-board LEDs. 
The red LED is connected to pin PC3  */
static void leds_init(void)
/* Initialize the boards on-board LEDs. 
The red LED is connected to pin PC3  */
static void leds_init(void)
{
    RCC->AHBENR |= RCC_AHBENR_GPIOCEN;
    LED_RED_PORT->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR3;
    LED_RED_PORT->OTYPER &= ~(GPIO_OTYPER_OT_3);
    LED_RED_PORT->MODER &= ~(GPIO_MODER_MODER3);
    LED_RED_PORT->MODER |= GPIO_MODER_MODER3_0;
    LED_RED_PORT->PUPDR &= ~(GPIO_PUPDR_PUPDR3);
    LED_RED_PORT->BRR = (1 << 3);
}