實例說明：
1、本實例是利用STM8單片機定時器TIM1的PWM輸入捕獲模式測量紅外遙控碼。 

2、紅外遙控碼格式為NEC紅外編碼。
3、紅外接收信號輸入接PC1（TIM1輸入通道1）。
4、采用外部晶振16M。
5、采用IAR FOR STM8開發環境。
6、程序代碼如下：
//--------------------------------------------------------------------
#include

#define uchar              unsigned char
#define uint                unsigned int

uchar IrRecStep = 0;                             //接收步驟
uchar IrIndex = 0;                                //接收位數
uchar IrRecFlag = 0;                             //接收完標志
uchar IrRecBuff[4];                               //接收緩沖區
uchar IrRecAddr1;                                //紅外地址碼
uchar IrRecAddr2;
uchar IrRecData1;                                //紅外數據碼
uchar IrRecData2;
uint IrCycle = 0;                                  //紅外周期
uint IrHigh = 0;                                   //占空比
const uchar IrCode[8]={0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80};

//--------引導碼低電平范圍------------------
#define IrHeadLow_Max       2300            //2300*4 = 9200us
#define IrHeadLow_Min        2100            //2100*4 = 8400us
//--------引導碼高電平范圍------------------
#define IrHeadHigh_Max      1250            //1250*4 = 5000us
#define IrHeadHigh_Min       1050            //1050*4 = 4200us
//--------數據0的周期范圍-------------------
#define IrData00_Max         300             //300*4 = 1200us
#define IrData00_Min          260             //260*4 = 1040us
//--------數據1的周期范圍-------------------
#define IrData10_Max         580             //580*4 = 2320us
#define IrData10_Min          540             //540*4 = 2160us
//--------數據0的占空比(高電平)范圍---------
#define IrData0_Max          160             //160*4 = 640us
#define IrData0_Min           120             //120*4 = 480us
//--------數據1的占空比(高電平)范圍---------
#define IrData1_Max          440             //440*4 = 1760us
#define IrData1_Min           400             //400*4 = 1600us
//----------------------------------------------------------
#define REMOTE_CLK_DIV       63              //63+1=64----16Mh/64=4us
#define REMOTE_ICF_FILTER   0x30

//延時程序
void Delay_ms( uint ms )
{ 
  uint i,j;
  for( j=0; j   { 
    for( i=0; i<1000; i++ )
    {;} 
  }
}

//紅外接收端口初始化
void Ir_Init(void)
{
  PC_DDR_DDR1 = 0;       //PC1為輸入
  PC_CR1_C11 = 1;
  PC_CR2_C21 = 0;
}

//使用TIM1的PWM輸入捕獲
void Ir_PWM_Init(void)
{ 
  TIM1_PSCRH = 0;
  TIM1_PSCRL = REMOTE_CLK_DIV;

  TIM1_CCER1 &= 0xee;//禁止輸入捕獲1，2
  TIM1_CCMR1 |= (REMOTE_ICF_FILTER + 0x01);// ch1到ti1fp1
  TIM1_CCER1 &= 0xec;//ch1 上升沿觸發
  TIM1_CCMR2 |= (REMOTE_ICF_FILTER + 0x02);// ch2選擇 ti1fp2上
  TIM1_CCER1 |= 0x20;//ch1 下降沿觸發 ic2
  TIM1_SMCR |= 0x54;//選源觸發源和觸發方式 復位
  TIM1_CCER1 |= 0x11;//使能輸入捕獲1，2
  TIM1_CR1 |= 0x05;
}

//紅外接收程序
void Ir_Receive(void)
{
  switch(IrRecStep)
  {
  case 0:
          IrIndex = 0;
          if ((TIM1_SR1_CC1IF == 1)&&(TIM1_SR1_CC2IF == 1))
          {
            IrHigh = (uint)(TIM1_CCR2H); 
            IrHigh = (IrHigh << 8) + TIM1_CCR2L;  //IrHigh占空比
            IrCycle = (uint)(TIM1_CCR1H);
            IrCycle = (IrCycle << 8) + TIM1_CCR1L;  //IrCycle周期
            //是否在引導碼低電平范圍內
            if (((IrCycle - IrHigh) < IrHeadLow_Max)&&((IrCycle - IrHigh) > IrHeadLow_Min))
            {
              IrRecStep = 1;
              TIM1_SR1_CC1IF = 0;
              TIM1_SR1_CC2IF = 0;
              TIM1_SR2_CC1OF = 0;
              TIM1_SR2_CC2OF = 0;
              TIM1_SR1_UIF = 0;
              
              IrRecBuff[0] = 0;
              IrRecBuff[1] = 0;
              IrRecBuff[2] = 0;
              IrRecBuff[3] = 0;
            }
          }
          break;
  case 1:
          if ((TIM1_SR2_CC1OF==1) || (TIM1_SR2_CC2OF==1) || (TIM1_SR1_UIF==1))
          { 
            IrRecStep = 0;
          }
          else
          { 
            if ((TIM1_SR1_CC1IF == 1)&&(TIM1_SR1_CC2IF == 1))
            { 
              IrHigh = (uint)(TIM1_CCR2H); 
              IrHigh = (IrHigh << 8) + TIM1_CCR2L;
              IrCycle = (uint)(TIM1_CCR1H); 
              IrCycle = (IrCycle << 8) + TIM1_CCR1L;
              //是否在引導碼高電平范圍內
              if ((IrHigh < IrHeadHigh_Max)&&(IrHigh > IrHeadHigh_Min))
              {
                IrRecStep = 2;
              }
            }
          }
          break;
  case 2:
          if ((TIM1_SR2_CC1OF==1) || (TIM1_SR2_CC2OF==1) || (TIM1_SR1_UIF==1))
          { 
            IrRecStep = 0;
          }
          else
          { 
            if ((TIM1_SR1_CC1IF == 1)&&(TIM1_SR1_CC2IF == 1))
            { 
              IrHigh = (uint)(TIM1_CCR2H); 
              IrHigh = (IrHigh << 8) + TIM1_CCR2L;
              IrCycle = (uint)(TIM1_CCR1H); 
              IrCycle = (IrCycle << 8) + TIM1_CCR1L;
              //周期是否在數據0范圍內
              if ((IrCycle > IrData00_Min)&&(IrCycle < IrData00_Max))
              {
                //高電平是否在數據0范圍內
                if ((IrHigh > IrData0_Min)&&(IrHigh < IrData0_Max))
                {
                  IrIndex++;
                }
                else
                {
                  IrRecStep = 0;
                }
              }
              //周期是否在數據1范圍內
              else if ((IrCycle > IrData10_Min)&&(IrCycle < IrData10_Max))
              {
                //高電平是否在數據1范圍內
                if ((IrHigh > IrData1_Min)&&(IrHigh < IrData1_Max))
                {
                  IrRecBuff[IrIndex >> 3] |= IrCode[IrIndex & 0x07];
                  IrIndex++;
                }
                else
                {
                  IrRecStep = 0;
                }
              }
              else
              {
                IrRecStep = 0;
              }
              if(IrIndex >= 32)
              {
                IrRecStep = 0;
                IrRecFlag = 1;
              }
            }
          }
          break;
  }
}
      
//時鐘初始化
void CLK_Init(void)
{
  CLK_ECKR=0x03;//外部時鐘寄存器 外部時鐘準備就緒，外部時鐘開
  CLK_SWCR=0x02;//切換控制寄存器 使能切換機制
  CLK_SWR=0xB4;//主時鐘切換寄存器 選擇HSE為主時鐘源*/