led.c

   1 #include "led.h"
   2 #include "stm32f411.h"
   3
   4 void
   5 led_init (void)
   6 {
   7   /* GPIOCEN: IO port C clock enable  */
   8   *RCC_AHB1ENR |= (1u << 2); /* 1: IO port C clock enabled  */
   9   /* MODERy[1:0]: Port x configuration bits (y = 0..15)  */
  10   *GPIOC_MODER &= ~(0b11u << 26); /* Clear PC13 bits  */
  11   *GPIOC_MODER |= (1u << 26); /* 01: General purpose output mode  */
  12
  13   /* PC13: 0 = LED on
  14    *       1 = LED off  */
  15 }
  16
  17 void
  18 led_on (void)
  19 {
  20   *GPIOC_ODR &= ~(1u << 13);
  21 }
  22
  23 void
  24 led_off (void)
  25 {
  26   *GPIOC_ODR |= (1u << 13);
  27 }
  28
  29 void
  30 led_toggle (void)
  31 {
  32   *GPIOC_ODR ^= (1u << 13);
  33 }