TIM2 interrupt behaviour

[fshah48]

Posted on March 23, 2017 at 13:47

I am using TIM2.CH2 input compare. No other interrupts are activated except TIM2.CH2. In TIM2_IRQ handler all IC bits except CH2 are set. Why?

Using STM32Discovery on IAR. I expect TIM2_IRQ to fire up on trigger from outside. It does but CH2 interrupt ic leared and all other 3 IC interrupt bits are SET. Why?

[Tesla DeLorean]

Posted on March 23, 2017 at 14:15

The register is just a latch of occurring events, it is gated with the Interrupt Enable to create physical interrupts, but you don't need to enable them for the latch to function.

[waclawek.jan]

Posted on March 23, 2017 at 14:17

Similar

https://community.st.com/0D50X00009Xkg8cSAB

[fshah48]

Posted on March 24, 2017 at 12:48

Well, I need to get interrupt to react. I also tried following:

TIM_GenerateEvent(TIM2, TIM_EventSource_CC2); from SysTick interrupt

handler to generate TIM2.CH2 IC interrupt. TIM2 interrupt responds but

CC2IF is cleared in TIM2-SR. All other capture bits are set.

Another surprise is that TIM2.PSC is set to 0 when I expressly set it to 3.

/* Time base configuration */

TIM_TimeBaseStructure.TIM_Period = 0xFFFF;

TIM_TimeBaseStructure.TIM_Prescaler = 3; // divide by 4

TIM_TimeBaseStructure.TIM_ClockDivision = 0;

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);

All these code snippets are imported from examples you provide.

Please help.

On Thu, Mar 23, 2017 at 6:17 PM, waclawek.jan <

[Tesla DeLorean]

Posted on March 24, 2017 at 14:22

Code shows you configuring TIM4 not TIM2

TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); // Not TIM2