STM32F4(用SysTick实现Delay函数)

1，开发环境

1，适用芯片：STM32F4全部芯片

2，固件库：STM32F4xx_DSP_StdPeriph_Lib_V1.8.0

3，IDE：MDK517

2，驱动源码

Delay.h文件

/****************************************************************

* Copyright (C) 2016, XinLi, all right reserved.

* File name: Delay.h

* Date: 2016.03.22

* Description: Delay Driver

*****************************************************************/

#ifndef __DELAY_H

#define __DELAY_H

/****************************************************************

* Header include

*****************************************************************/

#include "stm32f4xx.h"

/****************************************************************

* Macro definition

*****************************************************************/

/****************************************************************

* Type definition

*****************************************************************/

/****************************************************************

* Structure definition

*****************************************************************/

#ifdef __cplusplus

extern "C" {

#endif /* __cplusplus */

/****************************************************************

* Variable declaration

*****************************************************************/

/****************************************************************

* Function declaration

*****************************************************************/

void Delay_us(uint64_t nus);

void Delay_ms(uint64_t nms);

void Delay_s(uint64_t ns);

#ifdef __cplusplus

}

#endif /* __cplusplus */

#endif /* __DELAY_H */

Delay.c文件

/****************************************************************

* Copyright (C) 2016, XinLi, all right reserved.

* File name: Delay.c

* Date: 2016.03.22

* Description: Delay Driver

*****************************************************************/

/****************************************************************

* Header include

*****************************************************************/

#include "Delay.h"

/****************************************************************

* Global variables

*****************************************************************/

/****************************************************************

* Function declaration

*****************************************************************/

static void Delay_Init(void);

/****************************************************************

* Function definition

*****************************************************************/

/****************************************************************

* Function: Delay_Init

* Description: Delay Configuration.

* Input:

* Output:

* Return:

*****************************************************************/

static void Delay_Init(void)

{

static uint8_t first = 0;

if(first == 0)

{

first = 1;

SysTick_CLKSourceConfig(SysTick_CLKSource_HCLK_Div8);

SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk; /* Disability SysTick counter */

}

}

/****************************************************************

* Function: Delay_us

* Description: Microsecond delay.

* Input: nus

* Output:

* Return:

*****************************************************************/

void Delay_us(uint64_t nus)

{

uint32_t temp = 0;

uint64_t nms = 0;

Delay_Init();

if(nus == 0)

{

return;

}

nms = nus / 1000;

nus = nus % 1000;

if(nms > 0)

{

Delay_ms(nms);

}

if(nus > 0)

{

SysTick->LOAD = SystemCoreClock / 8000000 * nus; /* Time load (SysTick-> LOAD is 24bit) */

SysTick->VAL = 0x000000; /* Empty counter */

SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk; /* Start the countdown */

do

{

temp = SysTick->CTRL;

}

while(temp&0x01 && !(temp&(1<<16))); /* Wait time is reached */

SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk; /* Close Counter */

SysTick->VAL = 0x000000; /* Empty counter */

}

}

/****************************************************************

* Function: Delay_ms

* Description: Millisecond delay.

* Input: nms

* Output:

* Return:

*****************************************************************/

void Delay_ms(uint64_t nms)

{

uint32_t temp = 0;

Delay_Init();

if(nms == 0)

{

return;

}

while(nms > 500)

{

SysTick->LOAD = SystemCoreClock / 8000 * 500; /* Time load (SysTick-> LOAD is 24bit) */

SysTick->VAL = 0x000000; /* Empty counter */

SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk; /* Start the countdown */

do

{

temp = SysTick->CTRL;

}

while(temp&0x01 && !(temp&(1<<16))); /* Wait time is reached */

SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk; /* Close Counter */

SysTick->VAL = 0x000000; /* Empty counter */

nms -= 500;

}

SysTick->LOAD = SystemCoreClock / 8000 * nms; /* Time load (SysTick-> LOAD is 24bit) */

SysTick->VAL = 0x000000; /* Empty counter */

SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk; /* Start the countdown */

do

{

temp = SysTick->CTRL;

}

while(temp&0x01 && !(temp&(1<<16))); /* Wait time is reached */

SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk; /* Close Counter */

SysTick->VAL = 0x000000; /* Empty counter */

}

/****************************************************************

* Function: Delay_s

* Description: Second delay.

* Input: ns

* Output:

* Return:

*****************************************************************/

void Delay_s(uint64_t ns)

{

while(ns > 0)

{

Delay_ms(1000);

ns--;

}

}