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STM32F4 - Timer Sync - Trigger Mode does not work

Question asked by smrtkai on Feb 16, 2017
Latest reply on Feb 20, 2017 by smrtkai



I am having trouble to synchronize the start of two or more timers at the same time. Reading the manual, I figured out that, I have to select one timer as master timer with master configuration "Enable" ("the counter enable signal is used as a trigger output (TRGO). It is used to start several timers at the same time, ...").


The slaves are configured in slave mode "Trigger mode" ("the counter start at a rising edge of the trigger TRGI (but is not reset). Only the start of the counter is controlled.").


When I start the master timer with a delay, I expect the slave timer to start with the same delay. But the slave does start immediately. This is how my test code looks like:

HAL_TIM_OC_Start(&htim4, TIM_CHANNEL_2);
HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_4);

My master/slave configuration for the timers looks like this:


void MX_TIM3_Init(void) {

    sMasterConfig.MasterOutputTrigger = TIM_TRGO_ENABLE;
    sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_ENABLE;




void MX_TIM4_Init(void) {


    sSlaveConfig.SlaveMode = TIM_SLAVEMODE_TRIGGER;
    sSlaveConfig.InputTrigger = TIM_TS_ITR2;





I am using CubeMX and a STM32F4 Discovery Board.
Thank you for any help. I have no idea what I am missing. I have read the manual several times, I have checked the internal trigger connections and I have also checked the CR2 and SMCR registers.