Using Timer 2 to Capture Timer 3 via internal Interrupts

>The Trigger Output of the Timer is set to Master/Slave Mode Enabled

Contrary to its name, the MSM but does not do much, just shifts one of the internal signals by one or two cycles.

> and the Trigger Event is set to Compare Pulse (OC1).

Well, but you don't have Output compare set on CH1, do you? If yes, then the timer is not working in Encoder mode...

> The timer 3 will get reset as soon as timer 2 got a changing edge from its channels

How do you know it is reset exactly at that edge?

Also, read out and put the TIMs registers content.

JW

> Contrary to its name, the MSM but does not do much, just shifts one of the internal signals by one or two cycles.

"The effect of an event on the trigger input (TRGI) is delayed to allow a perfect synchronization between the current timer and its slaves (through TRGO). It is useful if we want to synchronize several timers on a single external event." - Okay, I see. So i dont even need to set MSM to enable internal communication between two timers.

> Well, but you don't have Output compare set on CH1, do you? If yes, then the timer is not working in Encoder mode...

The Channels 1 and 2 are automatically grayed out in STM32CubeIDE as soon as i activate encoder mode. The encoder mode functionallity works as intended os far. If I dont set the Compare Pulse (OC1) in timer 2 i wont get an interrupt in timer 3 to reset the timer.

> How do you know it is reset exactly at that edge?

To be honest, I assumed it. Even if the timer 2 only sends a trigger every rising edge or falling edge. Thats fine.

Is there a way to configure timer 3 to write the CNT value into a CC Register after getting reset by the ITR1?

Edit: To further clarify what I'm trying to achieve:

STM32F4 RM00090 Rev 18 Reference manual - p554/1749

"The timer, when configured in Encoder Interface mode provides information on the sensor’s current position.The user can obtain dynamic information (speed, acceleration, deceleration) by measuring the period between two encoder events using a second timer configured in capture mode. The output of the encoder which indicates the mechanical zero can be used for this purpose. Depending on the time between two events, the counter can also be read at regular times. This can be done by latching the counter value into a third input capture register if available (then the capture signal must be periodic and can be generated by another timer). when available, it is also possible to read its value through a DMA request generated by a real-time clock."

Markus

Which STM32?

Read out and post the TIMs registers' content.

(I did not realize that ST calls the CC1-> TRGO as "Compare Pulse", even if, contrary to other TRGO outputs, it is *not* bound to Compare... )

JW

µC: STM32F446RETx LQFP64 via NUCLEO F446RE

Config Timer 2

 htim2.Instance = TIM2;
 htim2.Init.Prescaler = 0;
 htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
 htim2.Init.Period = 4095;
 htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
 htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
 sConfig.EncoderMode = TIM_ENCODERMODE_TI12;
 sConfig.IC1Polarity = TIM_ICPOLARITY_RISING;
 sConfig.IC1Selection = TIM_ICSELECTION_DIRECTTI;
 sConfig.IC1Prescaler = TIM_ICPSC_DIV1;
 sConfig.IC1Filter = 0;
 sConfig.IC2Polarity = TIM_ICPOLARITY_RISING;
 sConfig.IC2Selection = TIM_ICSELECTION_DIRECTTI;
 sConfig.IC2Prescaler = TIM_ICPSC_DIV1;
 sConfig.IC2Filter = 0;
 if (HAL_TIM_Encoder_Init(&htim2, &sConfig) != HAL_OK)
 {
 Error_Handler();
 }
 sMasterConfig.MasterOutputTrigger = TIM_TRGO_OC1;
 sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;

Config Timer 3

htim3.Instance = TIM3;
 htim3.Init.Prescaler = 0;
 htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
 htim3.Init.Period = 65535;
 htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
 htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
 if (HAL_TIM_Base_Init(&htim3) != HAL_OK)
 {
 Error_Handler();
 }
 sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
 if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_TIM_IC_Init(&htim3) != HAL_OK)
 {
 Error_Handler();
 }
 sSlaveConfig.SlaveMode = TIM_SLAVEMODE_RESET;
 sSlaveConfig.InputTrigger = TIM_TS_ITR1;
 if (HAL_TIM_SlaveConfigSynchro(&htim3, &sSlaveConfig) != HAL_OK)
 {
 Error_Handler();
 }
 sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
 sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
 if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
 {
 Error_Handler();
 }
 sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;
 sConfigIC.ICSelection = TIM_ICSELECTION_TRC;
 sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;
 sConfigIC.ICFilter = 0;
 if (HAL_TIM_IC_ConfigChannel(&htim3, &sConfigIC, TIM_CHANNEL_1) != HAL_OK)
 {
 Error_Handler();
 }