STM32学习笔记15：SysTick（系统定时器）
eg:
系统定时时间 = SysTick_Config(SystemCoreClock / 100000)中的参数（SystemCoreClock / 100000）*（1/SystemCoreClock ）
延时时间 = Delay_us(100000) 中参数100 000 * 系统定时时间
注意：不过 1us 的中断没啥意义，整个程序的重心都花在进出中断上了，根本没有时间处理其他的任务
/**
******************************************************************************
* @file main.c
* @author fire
* @version V1.0
* @date 2014-xx-xx
* @brief 使用SysTick进行精确延时
******************************************************************************
* @attention
*
* 实验平台:秉火 STM32 F429 开发板
* 论坛 :http://www.firebbs.cn
* 淘宝 :http://firestm32.taobao.com
*
******************************************************************************
*/
#include "stm32f4xx.h"
#include "./led/bsp_led.h"
#include "./systick/bsp_SysTick.h"
/**
* @brief 主函数
* @param 无
* @retval 无
*/
int main(void)
{
/* LED 端口初始化 */
LED_GPIO_Config();
/* 配置SysTick 为10us中断一次,时间到后触发定时中断，
*进入stm32fxx_it.c文件的SysTick_Handler处理，通过数中断次数计时
*/
SysTick_Init();
while(1)
{
LED_RED;
Delay_us(100000); // 10000 * 10us = 1000ms
//Delay_ms(1000);
LED_GREEN;
Delay_us(100000); // 10000 * 10us = 1000ms
//Delay_ms(1000);
LED_BLUE;
Delay_us(100000); // 10000 * 10us = 1000ms
//Delay_ms(1000);
}
}
/*********************************************END OF FILE**********************/
/**
******************************************************************************
* @file bsp_SysTick.c
* @author fire
* @version V1.0
* @date 2015-xx-xx
* @brief SysTick 系统滴答时钟10us中断函数库,中断时间可自由配置，
* 常用的有 1us 10us 1ms 中断。
******************************************************************************
* @attention
*
* 实验平台:秉火 STM32 F429 开发板
* 论坛 :http://www.firebbs.cn
* 淘宝 :http://firestm32.taobao.com
*
******************************************************************************
*/
#include "./systick/bsp_SysTick.h"
static __IO u32 TimingDelay;
/**
* @brief 启动系统滴答定时器 SysTick
* @param 无
* @retval 无
*/
void SysTick_Init(void)
{
/* SystemFrequency / 1000 1ms中断一次
* SystemFrequency / 100000 10us中断一次
* SystemFrequency / 1000000 1us中断一次
*/
if (SysTick_Config(SystemCoreClock / 100000))//
{
/* Capture error */
while (1);
}
}
/**
* @brief us延时程序,10us为一个单位
* @param
* @arg nTime: Delay_us( 1 ) 则实现的延时为 1 * 10us = 10us
* @retval 无
*/
void Delay_us(__IO u32 nTime)
{
TimingDelay = nTime;
while(TimingDelay != 0);
}
/**
* @brief 获取节拍程序
* @param 无
* @retval 无
* @attention 在 SysTick 中断函数 SysTick_Handler()调用
*/
void TimingDelay_Decrement(void)
{
if (TimingDelay != 0x00)
{
TimingDelay--;
}
}
/*********************************************END OF FILE**********************/
/**
******************************************************************************
* @file Project/STM32F4xx_StdPeriph_Templates/stm32f4xx_it.c
* @author MCD Application Team
* @version V1.5.0
* @date 06-March-2015
* @brief Main Interrupt Service Routines.
* This file provides template for all exceptions handler and
* peripherals interrupt service routine.
******************************************************************************
* @attention
*
* © COPYRIGHT 2015 STMicroelectronics
*
* Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.st.com/software_license_agreement_liberty_v2
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "stm32f4xx_it.h"
extern void TimingDelay_Decrement(void);
/** @addtogroup STM32F429I_DISCOVERY_Examples
* @{
*/
/** @addtogroup FMC_SDRAM
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/******************************************************************************/
/* Cortex-M4 Processor Exceptions Handlers */
/******************************************************************************/
/**
* @brief This function handles NMI exception.
* @param None
* @retval None
*/
void NMI_Handler(void)
{
}
/**
* @brief This function handles Hard Fault exception.
* @param None
* @retval None
*/
void HardFault_Handler(void)
{
/* Go to infinite loop when Hard Fault exception occurs */
while (1)
{}
}
/**
* @brief This function handles Memory Manage exception.
* @param None
* @retval None
*/
void MemManage_Handler(void)
{
/* Go to infinite loop when Memory Manage exception occurs */
while (1)
{}
}
/**
* @brief This function handles Bus Fault exception.
* @param None
* @retval None
*/
void BusFault_Handler(void)
{
/* Go to infinite loop when Bus Fault exception occurs */
while (1)
{}
}
/**
* @brief This function handles Usage Fault exception.
* @param None
* @retval None
*/
void UsageFault_Handler(void)
{
/* Go to infinite loop when Usage Fault exception occurs */
while (1)
{}
}
/**
* @brief This function handles Debug Monitor exception.
* @param None
* @retval None
*/
void DebugMon_Handler(void)
{}
/**
* @brief This function handles SVCall exception.
* @param None
* @retval None
*/
void SVC_Handler(void)
{}
/**
* @brief This function handles PendSV_Handler exception.
* @param None
* @retval None
*/
void PendSV_Handler(void)
{}
/**
* @brief This function handles SysTick Handler.
* @param None
* @retval None
*/
void SysTick_Handler(void)
{
TimingDelay_Decrement();
}
/******************************************************************************/
/* STM32F4xx Peripherals Interrupt Handlers */
/* Add here the Interrupt Handler for the used peripheral(s) (PPP), for the */
/* available peripheral interrupt handler's name please refer to the startup */
/* file (startup_stm32f429_439xx.s). */
/******************************************************************************/
/**
* @}
*/
/**
* @}
*/
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/