STM8S003F定时器延时

一、前言

本次使用STM8S003F芯片，编译环境为IAR，至于新建工程什么的教程很多，这里就不多叙述了。其实官方例程里是有定时器延时的，使用定时器4固定频率，在中断里运行，就可以像系统一样按毫秒延时。

二、定时器初始化

#define TIM4_PERIOD 124
__IO uint32_t TimingDelay = 0;

/**
 * @brief  Configure TIM4 to generate an update interrupt each 1ms
 * @param  None
 * @retval None
 */

static void TIM4_Config(void)
{
  /* TIM4 configuration:
   - TIM4CLK is set to 16 MHz, the TIM4 Prescaler is equal to 128 so the TIM1 counter
   clock used is 16 MHz / 128 = 125 000 Hz
  - With 125 000 Hz we can generate time base:
      max time base is 2.048 ms if TIM4_PERIOD = 255 --> (255 + 1) / 125000 = 2.048 ms
      min time base is 0.016 ms if TIM4_PERIOD = 1   --> (  1 + 1) / 125000 = 0.016 ms
  - In this example we need to generate a time base equal to 1 ms
   so TIM4_PERIOD = (0.001 * 125000 - 1) = 124 */

  /* Time base configuration */
  TIM4_TimeBaseInit(TIM4_PRESCALER_128, TIM4_PERIOD);
  /* Clear TIM4 update flag */
  TIM4_ClearFlag(TIM4_FLAG_UPDATE);
  /* Enable update interrupt */
  TIM4_ITConfig(TIM4_IT_UPDATE, ENABLE);

  /* enable interrupts */
  enableInterrupts();

  /* Enable TIM4 */
  TIM4_Cmd(ENABLE);
}

三、定时器函数与中断处理

定时器函数初始化定时时间：

void Delay(__IO uint32_t nTime)
{
  TimingDelay = nTime;

  while (TimingDelay != 0)
    ;
}

中断函数：

void TimingDelay_Decrement(void)
{
  if (TimingDelay != 0x00)
  {
    TimingDelay--;
  }
}

在中断里增加中断函数：

extern void TimingDelay_Decrement(void);

 INTERRUPT_HANDLER(TIM4_UPD_OVF_IRQHandler, 23)
 {
   TimingDelay_Decrement();
  /* Cleat Interrupt Pending bit */
  TIM4_ClearITPendingBit(TIM4_IT_UPDATE);
 }