PY32F003F18滴答定时器

PY32F003F18滴答定时器使用HAL库函数

//函数功能:配置"SysTick计数器"每1ms中断一次,优先级为最低
HAL_StatusTypeDef HAL_Init(void)
{
  HAL_StatusTypeDef  status = HAL_OK;

  /* Configure Flash prefetch, Instruction cache             */
  /* Default configuration at reset is:                      */
  /* - Prefetch disabled                                     */
  /* - Instruction cache enabled                             */

  /* Use SysTick as time base source and configure 1ms tick (default clock after Reset is HSI) */
  if (HAL_InitTick(TICK_INT_PRIORITY) != HAL_OK)
  {
    status = HAL_ERROR;
  }
  else
  {
    /* Init the low level hardware */
    HAL_MspInit();//用户在PY32F0xx_hal_msp.c中定义的函数
  }

  /* Return function status */
  return status;
}


//函数功能:设置"SysTick计数器"重装载值为(SystemCoreClock * uwTickFreq/1000U -1),配置中断优先级,并使能计数和中断
//初始化成功返回0
//SystemCoreClock为系统时钟,单位为Hz
//HAL_TICK_FREQ_1KHZ=1表示周期为1ms
//全局变量uwTickFreq=HAL_TICK_FREQ_1KHZ,"SysTick计数器"中断周期为:uwTickFreq,单位为ms
//"SysTick计数器"重装载值为: (SystemCoreClock * uwTickFreq/1000U -1)
__weak HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority)
{
  HAL_StatusTypeDef  status = HAL_OK;//HAL_OK=0x00U

  if (uwTickFreq != 0U)//"SysTick计数器"的中断频率为1KHz,即中断周期为1ms
  {
    if (HAL_SYSTICK_Config( SystemCoreClock / (1000U/uwTickFreq) ) == 0U)
    {//设置"SysTick定时器"自动重装载值为SystemCoreClock / (1000U/uwTickFreq)-1
			//并设置中断优先级为最低,使能"SysTick定时器"时钟源,"SysTick定时器中断"和"SysTick定时器模块"
      if (TickPriority < (1UL << __NVIC_PRIO_BITS))
      {//如果TickPriority<4,表示"SysTick计数器"优先级正确
        HAL_NVIC_SetPriority(SysTick_IRQn, TickPriority, 0U);
				//设置"SysTick计数器"中断优先级为TickPriority,这个0无意义
        uwTickPrio = TickPriority;
				//记录中断优先级,后面要读取"SysTick计数器"中断优先级
      }
      else//"SysTick计数器"优先级不正确
      {
        status = HAL_ERROR;//HAL_ERROR=0x01U
      }
    }
    else//"SysTick计数器"的中断频率为0Hz
    {
      status = HAL_ERROR;//HAL_ERROR=0x01U
    }
  }
  else
  {
    status = HAL_ERROR;//HAL_ERROR=0x01U
  }

  return status;//Return function status
}

//设置"SysTick定时器"自动重装载值为TicksNumb-1,并设置中断优先级为最低,使能"SysTick定时器"时钟源,"SysTick定时器中断"和"SysTick定时器模块"
uint32_t HAL_SYSTICK_Config(uint32_t TicksNumb)
{
  return SysTick_Config(TicksNumb);
	//设置"SysTick定时器"自动重装载值为TicksNumb-1,并设置中断优先级为最低,使能"SysTick定时器"时钟源,"SysTick定时器中断"和"SysTick定时器模块"
}

//函数功能:设置"SysTick定时器"自动重装载值为ticks-1,并设置中断优先级为最低,使能"SysTick定时器"时钟源,"SysTick定时器中断"和"SysTick定时器模块"
__STATIC_INLINE uint32_t SysTick_Config(uint32_t ticks)
{
  if ((ticks - 1UL) > SysTick_LOAD_RELOAD_Msk)
  {//SysTick_LOAD_RELOAD_Msk=0xFFFFFF,系统滴答定时器为24位,这里做了限定
    return (1UL);//Reload value impossible
  }

  SysTick->LOAD  = (uint32_t)(ticks - 1UL);
	//设置"SysTick定时器"自动重装载值,set reload register

  NVIC_SetPriority (SysTick_IRQn, (1UL << __NVIC_PRIO_BITS) - 1UL);
	//设置"SysTick定时器"中断优先级为最低
	//set Priority for Systick Interrupt

  SysTick->VAL   = 0UL;
	//设置系统滴答定时器的初始计数值为0
	//Load the SysTick Counter Value

  SysTick->CTRL  = SysTick_CTRL_CLKSOURCE_Msk |
                   SysTick_CTRL_TICKINT_Msk   |
                   SysTick_CTRL_ENABLE_Msk;
	//使能"SysTick定时器"时钟源,使能"SysTick定时器中断"，使能"SysTick定时器模块"
	//Enable SysTick IRQ and SysTick Timer

  return (0UL);//Function successful
}

#include "py32f0xx_hal.h"

int main(void)
{
//	HSE_Config();
	//初始化"HSI,HSE,LSI振荡器",HSE用作系统时钟(SYSCLK),同时配置"AHB时钟(HCLK)和APB时钟(PCLK)"

	uwTickFreq=HAL_TICK_FREQ_1KHZ;//准备配置"SysTick定时器"每1ms中断一次
	HAL_InitTick(PRIORITY_LOWEST);//配置"SysTick定时器"每1ms中断一次,优先级为最低
//	HAL_Init();

	HAL_Delay(1000);

  while (1)
  {
		HAL_Delay(500);
  }
}

//函数功能:延时x_ms毫秒
void Delay_ms(uint32_t x_ms)
{
	uint8_t flag;
  uint32_t tickstart;
	uint32_t tickend;
	uint32_t tmp;

	tickstart = HAL_GetTick();
	//读取"SysTick计数器"的中断次数计数器uwTick

	flag=1;
	if (x_ms==0) flag=0;
	while (flag)
	{
		tickend=HAL_GetTick();
		//读取"SysTick计数器"的中断次数计数器uwTick
		if(tickend>=tickstart) tickend=tickend - tickstart;
		else
		{
			tmp=0xFFFFFFFF;
			tmp=tmp-tickstart;
			tickend=tickend+tmp;
//			tickend=tickend+0xFFFFFFFF-tickstart;
		}
		if ( tickend > x_ms) flag=0;//超时
	}
}

   我觉得直接调用，会更加清晰易懂，如下：
    uwTickFreq=HAL_TICK_FREQ_1KHZ;//准备配置"SysTick定时器"每1ms中断一次
    HAL_InitTick(PRIORITY_LOWEST);//配置"SysTick定时器"每1ms中断一次,优先级为最低

 

几个很重要的用户函数

//函数功能:供SysTick_Handler()调用
__weak void HAL_IncTick(void)
{
  uwTick += uwTickFreq;
	//SysTick计数器"每中断一次,中断次数计数器uwTick=uwTick+uwTickFreq
	//uwTickFreq为"SysTick计数器"的中断频率
}

//函数功能:读取"SysTick计数器"的中断次数计数器uwTick
__weak uint32_t HAL_GetTick(void)
{
  return uwTick;
}

//函数功能:读取"SysTick计数器"的中断优先级
uint32_t HAL_GetTickPrio(void)
{
  return uwTickPrio;//将"SysTick计数器"的中断优先级返回
}

//函数功能:读取"SysTick计数器"的中断频率
uint32_t HAL_GetTickFreq(void)
{
  return uwTickFreq;//读取"SysTick计数器"的中断频率
}

//函数功能:延时Delay毫秒
//Delay为延时的毫秒数值
__weak void HAL_Delay(uint32_t Delay)
{
  uint32_t tickstart = HAL_GetTick();
	//读取"SysTick计数器"的中断次数计数器uwTick
	//使用tickstart记录"中断次数计数器的初始值"
  uint32_t wait = Delay;

  /* Add a freq to guarantee minimum wait */
  if (wait < HAL_MAX_DELAY)
  {
    wait += (uint32_t)(uwTickFreq);
		//计算至少需要等待的"中断次数"
		//uwTickFreq为"SysTick计数器"的中断频率
  }

  while ((HAL_GetTick() - tickstart) < wait)
  {
		//HAL_GetTick()读取"SysTick计数器"的中断次数计数器uwTick
  }
}

//函数功能:不使能"SysTick计数器"中断
__weak void HAL_SuspendTick(void)
{
  CLEAR_BIT(SysTick->CTRL,SysTick_CTRL_TICKINT_Msk);
	//不使能"SysTick计数器"中断,Disable SysTick Interrupt
}

//函数功能:使能"SysTick计数器"中断
__weak void HAL_ResumeTick(void)
{
  /* Enable SysTick Interrupt */
  SET_BIT(SysTick->CTRL, SysTick_CTRL_TICKINT_Msk);
	//使能"SysTick计数器"中断,Enable SysTick Interrupt
}