Lập trình ngắt timer STM32F4

Hàm khởi tạo ngắt STM32F4

void TIM_INT_Init()
{
    // Enable clock for TIM2
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    // TIM2 initialization overflow every 500ms
    // TIM2 by default has clock of 84MHz
    // Here, we must set value of prescaler and period,
    // so update event is 0.5Hz or 500ms
    // Update Event (Hz) = timer_clock / ((TIM_Prescaler + 1) * 
    // (TIM_Period + 1))
    // Update Event (Hz) = 84MHz / ((4199 + 1) * (9999 + 1)) = 2 Hz
    TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
    TIM_TimeBaseInitStruct.TIM_Prescaler = 4199;
    TIM_TimeBaseInitStruct.TIM_Period = 9999;
    TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up;

    // TIM2 initialize
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStruct);
    // Enable TIM2 interrupt
    TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
    // Start TIM2
    TIM_Cmd(TIM2, ENABLE);

    // Nested vectored interrupt settings
    // TIM2 interrupt is most important (PreemptionPriority and 
    // SubPriority = 0)
    NVIC_InitTypeDef NVIC_InitStruct;
    NVIC_InitStruct.NVIC_IRQChannel = TIM2_IRQn;
    NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStruct);
}

Chương trình ngắt tạo timer

void TIM2_IRQHandler()
{
    // Checks whether the TIM2 interrupt has occurred or not
    if (TIM_GetITStatus(TIM2, TIM_IT_Update))
    {
        // Toggle orange LED (GPIO13)
        GPIO_ToggleBits(GPIOD, GPIO_Pin_13);

        // Clears the TIM2 interrupt pending bit
        TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
    }
}

#include "stm32f4xx.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_tim.h"
#include "misc.h"
#include "clock.h"
#include "delay.h"

int main(void)
{
    // Set clock to 168MHz
    CLOCK_SetClockTo168MHz();

    // Delay initialization
    DELAY_Init();

    // Timer interrupt initialization
    TIM_INT_Init();

    // Clock for GPIOD
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);

    // GPIOD initialization as an output for orange LED (GPIOD13)
    // and blue LED (GPIOD15)
    GPIO_InitTypeDef GPIO_InitStruct;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_15;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_2MHz;
    GPIO_Init(GPIOD, &GPIO_InitStruct);

    while (1)
    {
        // Toggle blue LED (GPIO15)
        GPIO_ToggleBits(GPIOD, GPIO_Pin_15);
        // Delay 2.5s
        DELAY_Ms(2500);
    }
}