====== Časovač - Input Capture ======

<code c>
#include "stm32f4xx.h"

void initInput(void){
  RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN;

  // PA0 - alternate function for Input Capture Mode
  GPIOA->PUPDR |= GPIO_PULLUP << GPIO_PUPDR_PUPD0_Pos;
  GPIOA->MODER |= GPIO_MODE_AF_PP << GPIO_MODER_MODER0_Pos;
  GPIOA->AFR[0] |= GPIO_AF1_TIM2 << GPIO_AFRL_AFSEL0_Pos;
}

void initTIM2(void){
  RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;	// povoleni hodin do bloku TIM2
  
  TIM2->PSC = 1600;
  TIM2->ARR = 10000;

  // input capture enable for PA1
  TIM2->CCMR1 |= 0x01 << TIM_CCMR1_CC1S_Pos;	// set TI1 as input mode
  TIM2->CCER |= TIM_CCER_CC1P;			// falling edge
  TIM2->CCER |= TIM_CCER_CC1E;			// Capture enabled
}

int main(void){
    initInput();
    initTIM2();
    while(1){
      // process data from TIM2->CCR1
    }
}

</code>