原创 使用STM32 Timer的Gate模式来精确控制脉冲个数

策略:

用到了Timer Master Slave中的Gate模式
比如TIM1输出PWM， 频率为F
可以用TIM2通过Gate来控制TIM1的输出
将TIM2预频设为1/(F*2)，则TIM2的Period 就是 脉冲个数*2 - 1

/*           1     2     3     4     5     6     7     8     9
             __    __    __    __    __    __    __    __    __           
            |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |            
TIM1:    ___|  |__|  |__|  |__|  |__|  |__|  |__|  |__|  |__|  |____________________
          ->| Period1|<-
             1) 2) 3) 4) 5) 6) 7) 8) 9) 10)11)12)13)14)15)16)17)
             __________________________________________________  
            |                                                  |  
TIM2:    ___|                                                  |____________________
          ->|  |<--- Pres2 = Period1/2
            |<------------  Period2 =  N*2-1 = 17 ------------>|
 */

实现代码

软件:
IAR 4.42限制版
ST库    2.01
硬件:
万利199开发板 STM3210B-LK1
/*0001*/  /* Includes ------------------------------------------------------------------*/
/*0002*/  #include "stm32f10x_lib.h"
/*0003*/  
/*0004*/  /* Private typedef -----------------------------------------------------------*/
/*0005*/  /* Private define ------------------------------------------------------------*/
/*0006*/  /* Private macro -------------------------------------------------------------*/
/*0007*/  /* Private variables ---------------------------------------------------------*/
/*0008*/  ErrorStatus HSEStartUpStatus;
/*0009*/  
/*0010*/  /* Private function prototypes -----------------------------------------------*/
/*0011*/  void  RCC_Configuration(void);
/*0012*/  void  NVIC_Configuration(void);
/*0013*/  /* Private functions ---------------------------------------------------------*/
/*0014*/  
/*0015*/  #define   PWM_Period      120
/*0016*/  int main(void)
/*0017*/  {
/*0018*/    u16       waveNumber = 10;
/*0019*/    /* System Clocks Configuration */
/*0020*/    RCC_Configuration();
/*0021*/  
/*0022*/    /* Enable related peripheral clocks */
/*0023*/    RCC_APB2PeriphClockCmd(  RCC_APB2Periph_GPIOA,ENABLE);
/*0024*/    RCC_APB2PeriphClockCmd(  RCC_APB2Periph_GPIOB,ENABLE);
/*0025*/    RCC_APB2PeriphClockCmd(  RCC_APB2Periph_TIM1,ENABLE);
/*0026*/    RCC_APB1PeriphClockCmd(  RCC_APB1Periph_TIM3,ENABLE);
/*0027*/    
/*0028*/    /* Config IO for related timers */
/*0029*/    {
/*0030*/      GPIO_InitTypeDef GPIO_InitStructure;
/*0031*/      /* Timer1 Channel 2, PA9 */
/*0032*/      GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_9;
/*0033*/      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
/*0034*/      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
/*0035*/      GPIO_Init(GPIOA, &GPIO_InitStructure);
/*0036*/      /* Timer3 Channel 4, PB1*/
/*0037*/      GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_1;
/*0038*/      GPIO_Init(GPIOB, &GPIO_InitStructure);
/*0039*/    }
/*0040*/    /* Setup Timer3 channel 4, Timer3 is master timer
|*0041*|       This timer is used to control the waveform count of timer1 */
/*0042*/    {
/*0043*/      TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
/*0044*/      TIM_OCInitTypeDef  TIM_OCInitStructure;
/*0045*/      TIM_DeInit(TIM3);
/*0046*/      TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
/*0047*/      TIM_OCStructInit(&TIM_OCInitStructure);
/*0048*/      TIM_TimeBaseStructure.TIM_Prescaler = PWM_Period/2 - 1;
/*0049*/      TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
/*0050*/      TIM_TimeBaseStructure.TIM_Period = waveNumber*2;
/*0051*/      TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
/*0052*/      TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);
/*0053*/      
/*0054*/      /* Timer2 Channel 3 Configuration in PWM2 mode, this is used for enable Recive clcok */
/*0055*/      TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
/*0056*/      TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
/*0057*/      TIM_OCInitStructure.TIM_Pulse = waveNumber*2 - 1;
/*0058*/      TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
/*0059*/      TIM_OC4Init(TIM3,&TIM_OCInitStructure);
/*0060*/      TIM_CtrlPWMOutputs(TIM3, ENABLE);
/*0061*/      TIM_SelectOnePulseMode(TIM3, TIM_OPMode_Single);
/*0062*/    }
/*0063*/    /* Setup timer1 channel 2, Timer1 is slave timer 
|*0064*|       This timer is used to output waveforms */
/*0065*/    {
/*0066*/      TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
/*0067*/      TIM_OCInitTypeDef  TIM_OCInitStructure;
/*0068*/      TIM_DeInit(TIM1);
/*0069*/      TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
/*0070*/      TIM_OCStructInit(&TIM_OCInitStructure);
/*0071*/      TIM_TimeBaseStructure.TIM_Prescaler = 0;
/*0072*/      TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
/*0073*/      TIM_TimeBaseStructure.TIM_Period = PWM_Period;
/*0074*/      TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
/*0075*/      TIM_TimeBaseInit(TIM1,&TIM_TimeBaseStructure);
/*0076*/      
/*0077*/      /* Timer2 Channel 3 Configuration in PWM2 mode, this is used for enable Recive clcok */
/*0078*/      TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
/*0079*/      TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
/*0080*/      TIM_OCInitStructure.TIM_Pulse = PWM_Period/2;
/*0081*/      TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
/*0082*/      TIM_OC2Init(TIM1,&TIM_OCInitStructure);
/*0083*/      TIM_CtrlPWMOutputs(TIM1, ENABLE);
/*0084*/    }
/*0085*/    /* Create relationship between timer1 and timer3, timer3 is master, timer1 is slave
|*0086*|      timer1 is work under gate control mode, and controled by timer3
|*0087*|      timer3's channel 4 is used as the control signal
|*0088*|     */
/*0089*/      /* Enable timer's master/slave work mode */
/*0090*/      TIM_SelectMasterSlaveMode(TIM3,TIM_MasterSlaveMode_Enable);
/*0091*/      TIM_SelectMasterSlaveMode(TIM1,TIM_MasterSlaveMode_Enable);
/*0092*/      /* timer3's channel 4 is used as the control signal */
/*0093*/      TIM_SelectOutputTrigger(TIM3,TIM_TRGOSource_OC4Ref );
/*0094*/      /* Check the master/slave is valid or not */
/*0095*/      compile_assert((u16)GetInternalTrigger(TIM1,TIM3) != (u16)-1); 
/*0096*/      /* Config timer1's external clock */
/*0097*/      TIM_ITRxExternalClockConfig(TIM1, GetInternalTrigger(TIM1,TIM3));
/*0098*/      TIM_SelectSlaveMode(TIM1,TIM_SlaveMode_Gated);
/*0099*/      
/*0100*/    /* Enable the slave tiemr*/
/*0101*/    TIM_Cmd(TIM1,ENABLE);
/*0102*/    //SetupAlltimers();
/*0103*/    while(1){
/*0104*/      /* Check whether the previous action is done or not */
/*0105*/      if(!(TIM3->CR1 & 1)){
/*0106*/        TIM1->CNT = 0; /* It would be very perfect if gate mode can 
|*0107*|                          reset the slave timer automatically */
/*0108*/        TIM3->ARR = waveNumber*2;  /* Reload wave number*/
/*0109*/        TIM3->CCR4 = waveNumber*2 - 1;
/*0110*/        TIM3->CR1|=1; /* Re-enable the timer */
/*0111*/        /* update waveform number */
/*0112*/        waveNumber++;
/*0113*/        if(waveNumber == 13){
/*0114*/          waveNumber = 10;
/*0115*/        }
/*0116*/      }
/*0117*/    }
/*0118*/  }
/*0119*/  
/*0120*/  /*******************************************************************************
|*0121*|  * Function Name  : RCC_Configuration
|*0122*|  * Description    : Configures the different system clocks.
|*0123*|  * Input          : None
|*0124*|  * Output         : None
|*0125*|  * Return         : None
|*0126*|  *******************************************************************************/
/*0127*/  void RCC_Configuration(void)
/*0128*/  {
/*0129*/    /* RCC system reset(for debug purpose) */
/*0130*/    RCC_DeInit();
/*0131*/  
/*0132*/    /* Enable HSE */
/*0133*/    RCC_HSEConfig(RCC_HSE_ON);
/*0134*/  
/*0135*/    /* Wait till HSE is ready */
/*0136*/    HSEStartUpStatus = RCC_WaitForHSEStartUp();
/*0137*/  
/*0138*/    if(HSEStartUpStatus == SUCCESS)
/*0139*/    {
/*0140*/      /* Enable Prefetch Buffer */
/*0141*/      FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
/*0142*/  
/*0143*/      /* Flash 2 wait state */
/*0144*/      FLASH_SetLatency(FLASH_Latency_2);
/*0145*/   
/*0146*/      /* HCLK = SYSCLK */
/*0147*/      RCC_HCLKConfig(RCC_SYSCLK_Div1); 
/*0148*/    
/*0149*/      /* PCLK2 = HCLK */
/*0150*/      RCC_PCLK2Config(RCC_HCLK_Div1); 
/*0151*/  
/*0152*/      /* PCLK1 = HCLK/2 */
/*0153*/      RCC_PCLK1Config(RCC_HCLK_Div2);
/*0154*/  
/*0155*/      /* PLLCLK = 8MHz * 9 = 72 MHz */
/*0156*/      RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);
/*0157*/  
/*0158*/      /* Enable PLL */ 
/*0159*/      RCC_PLLCmd(ENABLE);
/*0160*/  
/*0161*/      /* Wait till PLL is ready */
/*0162*/      while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
/*0163*/      {
/*0164*/      }
/*0165*/  
/*0166*/      /* Select PLL as system clock source */
/*0167*/      RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
/*0168*/  
/*0169*/      /* Wait till PLL is used as system clock source */
/*0170*/      while(RCC_GetSYSCLKSource() != 0x08)
/*0171*/      {
/*0172*/      }
/*0173*/    }
/*0174*/  }

效果如下图