Using timer in slave mode and trigger source as ITR1

[SivaP.]

Hello I am new to stm32 MCUs. Timer1 is in slave mode and the trigger source is ITR1. What is ITR1 and in which conditions is timer generating pulses if it is in slave mode? I generated a code using mcsdk for stm32g431cbu6.

Please check line 25 in the code.

static void MX_TIM1_Init(void)
{
  TIM_SlaveConfigTypeDef sSlaveConfig = {0};
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIMEx_BreakInputConfigTypeDef sBreakInputConfig = {0};
  TIM_OC_InitTypeDef sConfigOC = {0};
  TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};
 
  htim1.Instance = TIM1;
  htim1.Init.Prescaler = ((TIM_CLOCK_DIVIDER) - 1);
  htim1.Init.CounterMode = TIM_COUNTERMODE_CENTERALIGNED1;
  htim1.Init.Period = ((PWM_PERIOD_CYCLES) / 2);
  htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV2;
  htim1.Init.RepetitionCounter = (REP_COUNTER);
  htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_Base_Init(&htim1) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_TIM_PWM_Init(&htim1) != HAL_OK)
  {
    Error_Handler();
  }
  sSlaveConfig.SlaveMode = TIM_SLAVEMODE_TRIGGER;
  sSlaveConfig.InputTrigger = TIM_TS_ITR1;
  if (HAL_TIM_SlaveConfigSynchro(&htim1, &sSlaveConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_OC4REF;
  sMasterConfig.MasterOutputTrigger2 = TIM_TRGO2_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sBreakInputConfig.Source = TIM_BREAKINPUTSOURCE_COMP1;
  sBreakInputConfig.Enable = TIM_BREAKINPUTSOURCE_ENABLE;
  sBreakInputConfig.Polarity = TIM_BREAKINPUTSOURCE_POLARITY_HIGH;
  if (HAL_TIMEx_ConfigBreakInput(&htim1, TIM_BREAKINPUT_BRK2, &sBreakInputConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sBreakInputConfig.Source = TIM_BREAKINPUTSOURCE_COMP2;
  if (HAL_TIMEx_ConfigBreakInput(&htim1, TIM_BREAKINPUT_BRK2, &sBreakInputConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sBreakInputConfig.Source = TIM_BREAKINPUTSOURCE_COMP4;
  if (HAL_TIMEx_ConfigBreakInput(&htim1, TIM_BREAKINPUT_BRK2, &sBreakInputConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = ((PWM_PERIOD_CYCLES) / 4);
  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();
  }
  if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_2) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_3) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigOC.OCMode = TIM_OCMODE_PWM2;
  sConfigOC.Pulse = (((PWM_PERIOD_CYCLES) / 2) - (HTMIN));
  if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_4) != HAL_OK)
  {
    Error_Handler();
  }
  sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_ENABLE;
  sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_ENABLE;
  sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_1;
  sBreakDeadTimeConfig.DeadTime = ((DEAD_TIME_COUNTS) / 2);
  sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;
  sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;
  sBreakDeadTimeConfig.BreakFilter = 0;
  sBreakDeadTimeConfig.BreakAFMode = TIM_BREAK_AFMODE_INPUT;
  sBreakDeadTimeConfig.Break2State = TIM_BREAK2_ENABLE;
  sBreakDeadTimeConfig.Break2Polarity = TIM_BREAK2POLARITY_HIGH;
  sBreakDeadTimeConfig.Break2Filter = 3;
  sBreakDeadTimeConfig.Break2AFMode = TIM_BREAK_AFMODE_INPUT;
  sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;
  if (HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN TIM1_Init 2 */
 
  /* USER CODE END TIM1_Init 2 */
  HAL_TIM_MspPostInit(&htim1);
 
}

[KnarfB]

Application note AN4013 STM32 cross-series timer overview

has some general info on that.

Specific info like the trigger connect matrix is in the reference manual RM 0440, Table 252. TIMx internal trigger connection.

If you are new, start with the simplest timer you can find for your purpose, timers can be beasts.

hth

KnarfB

[waclawek.jan]

First, read the TIM chapter in RM. Then get TIM1 working without setting it as slave.

Note, that for PWM output in TIM1 (which is an Advanced Timer), you should have TIMx_BDCR.MOE set. I don't use Cube so don't know if you do that in code above. Read out the TIM registers to check.

Then, if its slave-mode controller is set to Trigger mode in TIMx_SMCR.SMS, and you haven't enabled counter by setting TIMx_CR1.CEN, the first trigger which arrives will set TIMx_CR1.CEN in hardware thus start the counter (and conversely that should start pulses to output, if all other things are set correctly, which you should check first, as I've said above).

> What is ITR1

Read TIM chapter in RM.

 

Using Cube, instead of programming directly registers, makes this harder to understand. At least read out and check the TIM1 register's content, after having carefully read the TIM chapter in RM.

JW