一、文件main.c
#include "stm32f10x.h"
#include "SysTick.h"
/*
* 函數名：main
* 描述 ：主函數
* 輸入 ：無
* 輸出 ：無
*/
int main(void)
{
/* 配置SysTick 為10us中斷一次 */
SysTick_Init();
for(;;)
{
Delay_us(50000); // 50000 * 10us = 500ms
}
}
二、文件SysTick..c對SysTick_Init進行初始化
void SysTick_Init(void)
{
/* SystemFrequency / 1000 1ms中斷一次
* SystemFrequency / 100000 10us中斷一次
* SystemFrequency / 1000000 1us中斷一次
*/
//if (SysTick_Config(SystemFrequency / 100000))// ST3.0.0庫版本
if (SysTick_Config(SystemCoreClock / 100000))// ST3.5.0庫版本
{
while (1);/* Capture error */
}
SysTick->CTRL &= ~ SysTick_CTRL_ENABLE_Msk;// 關閉滴答定時器
}
三、文件system_stm32f10x.c中定義SystemCoreClock
uint32_t SystemCoreClock = SYSCLK_FREQ_72MHz; /*!< System Clock Frequency (Core Clock) */
四、文件core_cm3.h里的函數SysTick_Config
static __INLINE uint32_t SysTick_Config(uint32_t ticks)
{
if (ticks > SysTick_LOAD_RELOAD_Msk) return (1); /* Reload value impossible */
SysTick->LOAD = (ticks & SysTick_LOAD_RELOAD_Msk) - 1; /* set reload register */
NVIC_SetPriority (SysTick_IRQn, (1<<__NVIC_PRIO_BITS) - 1); /* set Priority for Cortex-M0 System Interrupts */
SysTick->VAL = 0; /* Load the SysTick Counter Value */
SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk |
SysTick_CTRL_TICKINT_Msk |
SysTick_CTRL_ENABLE_Msk; /* Enable SysTick IRQ and SysTick Timer */
return (0); /* Function successful */
}
五、文件core_cm3.h
#define SysTick_CTRL_CLKSOURCE_Pos 2 /*!< SysTick CTRL: CLKSOURCE Position */
#define SysTick_CTRL_CLKSOURCE_Msk (1ul << SysTick_CTRL_CLKSOURCE_Pos) /*!< SysTick CTRL: CLKSOURCE Mask */
#define SysTick_CTRL_TICKINT_Pos 1 /*!< SysTick CTRL: TICKINT Position */
#define SysTick_CTRL_TICKINT_Msk (1ul << SysTick_CTRL_TICKINT_Pos) /*!< SysTick CTRL: TICKINT Mask */
#define SysTick_CTRL_ENABLE_Pos 0 /*!< SysTick CTRL: ENABLE Position */
#define SysTick_CTRL_ENABLE_Msk (1ul << SysTick_CTRL_ENABLE_Pos) /*!< SysTick CTRL: ENABLE Mask */
/* SysTick Reload Register Definitions */
#define SysTick_LOAD_RELOAD_Pos 0 /*!< SysTick LOAD: RELOAD Position */
#define SysTick_LOAD_RELOAD_Msk (0xFFFFFFul << SysTick_LOAD_RELOAD_Pos)
六、文件SysTick.c
static __IO u32 TimingDelay;
void Delay_us(__IO u32 nTime)
{
TimingDelay = nTime;
SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk;// 使能滴答定時器
while(TimingDelay != 0);
}
七、文件SysTick.c
void TimingDelay_Decrement(void)
{
if (TimingDelay != 0x00)
{
TimingDelay--;
}
}
八、文件stm32f10x_it.c
SystemCoreClock / 100000=10us中斷一次，TimingDelay為總中斷次數
extern void TimingDelay_Decrement(void);
void SysTick_Handler(void)
{
TimingDelay_Decrement();
}