定时器在相同设置下的行为不同

Question

我正在使用 STM32F401RCT6 芯片，我正在尝试做一些受控的 PWM 输出。我将 TIM1、2、3 和 11 用于 PWM。

问题是，当我为定时器 1 设置与任何其他定时器相同的周期时，周期长度相同但脉冲不同。例如，TIM1 是 6.9us 的脉冲，其他的是 82.4us，当使用周期 4999 时。

The picture shows that the period is the same.

The next picture shows the difference in the pulse length.

当我将脉冲从 10 更改为 1000 时，TIM1 的脉冲为 720us，TIM2 的脉冲为 794us。

当我看到不同之处时，首先想到的是定时器有不同的频率，但问题是它也会有不同的PWM脉冲频率，但事实并非如此。

谁能说说定时器1的脉冲长度变短的原因是什么？

我的设置如下：

void MX_TIM11_Init(void)
{
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIM_OC_InitTypeDef sConfigOC = {0};

  htim11.Instance = TIM11;
  htim11.Init.Prescaler = HAL_RCC_GetPCLK2Freq()/124999;
  htim11.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim11.Init.Period = 0;
  htim11.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim11.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_Base_Init(&htim11) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_TIM_PWM_Init(&htim11) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_OC1REF;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_ENABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = 0;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  if (HAL_TIM_PWM_ConfigChannel(&htim11, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }
  HAL_TIM_MspPostInit(&htim11);
}

void MX_TIM2_Init(void)
{
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIM_OC_InitTypeDef sConfigOC = {0};

  htim2.Instance = TIM2;
  htim2.Init.Prescaler = HAL_RCC_GetPCLK1Freq()/124999;
  htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim2.Init.Period = 0;
  htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_PWM_Init(&htim2) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_OC1REF;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_ENABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = 0;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  if (HAL_TIM_PWM_ConfigChannel(&htim2, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }
  HAL_TIM_MspPostInit(&htim2);
}

void MX_TIM3_Init(void)
{
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIM_OC_InitTypeDef sConfigOC = {0};

  htim3.Instance = TIM3;
  htim3.Init.Prescaler = HAL_RCC_GetPCLK1Freq()/124999;
  htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim3.Init.Period = 0;
  htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_PWM_Init(&htim3) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_OC1REF;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_ENABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = 0;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  if (HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }
  HAL_TIM_MspPostInit(&htim3);
}

void MX_TIM1_Init(void)
{
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIM_OC_InitTypeDef sConfigOC = {0};
  TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};

  htim1.Instance = TIM1;
  htim1.Init.Prescaler = HAL_RCC_GetPCLK2Freq()/124999;
  htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim1.Init.Period = 0;
  htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim1.Init.RepetitionCounter = 0;
  htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_PWM_Init(&htim1) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_OC1REF;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_ENABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = 0;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;
  sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
  if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }
  sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;
  sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;
  sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;
  sBreakDeadTimeConfig.DeadTime = 0;
  sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;
  sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;
  sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;
  if (HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig) != HAL_OK)
  {
    Error_Handler();
  }
  HAL_TIM_MspPostInit(&htim1);
}

我有以下功能来设置 PWM 参数并启动它：

void setPWM(TIM_HandleTypeDef timer, uint32_t channel, uint16_t period)
{
    // stop generation of PWM
    HAL_TIM_PWM_Stop(&timer, channel);
    TIM_OC_InitTypeDef sConfigOC;
    // set the period duration
    timer.Init.Period = period;
    // re-initialize with new period value
    HAL_TIM_PWM_Init(&timer);
    sConfigOC.OCMode = TIM_OCMODE_PWM1;
    // set the pulse duration
    sConfigOC.Pulse = 10;
    sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
    sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
    HAL_TIM_PWM_ConfigChannel(&timer, &sConfigOC, channel);
    // start PWM generation
    HAL_TIM_PWM_Start(&timer, channel);
}

更新：我需要在运行期间更改时间段，似乎如果我多次调用 setPWM 函数，就会出现问题。第一个电话似乎表现正常。奇怪的是，我对所有计时器都以相同的方式调用它，但只有一个会丢失脉冲长度。但是现在我运行不知道如何找到问题的核心。

知道我可以尝试找出是什么原因吗？

谢谢，哈娜

Answer 1

我现在所有的计时器都以同样的方式工作。我不确定为什么它对定时器 1 的反应不同，但如果我不再次调用 setPWM() 而只是在运行时设置 ARR 寄存器，它对所有定时器的行为都相同。

timer.Instance->ARR = period;

定时器在相同设置下的行为不同

Timers behave differently with the same settings

c

stm32