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TIMER Update Event Not Affected from Changing CLOCK DIVISION Value

Question asked by Mesut TOPUZLU on Jun 29, 2017
Latest reply on Mar 4, 2018 by Daniel Koster

Hi. I use Keil Compiler and HAL lib. I configure TIM4 as normal timer (time base counter) and implement Update event with HAL_TIM_PeriodElapsedCallback function. My initialization code below;

 

__HAL_RCC_TIM4_CLK_ENABLE(); 
TIM4_Handler.Instance=TIM4;
TIM4_Handler.Init.Prescaler=16000; // 16 MHZ/16000 = 1000 Hz -> 1 ms inc/dec period
TIM4_Handler.Init.CounterMode=TIM_COUNTERMODE_UP;
TIM4_Handler.Init.Period=1000; // 1msec x 1000 = 1 sec overflow inerrupt
TIM4_Handler.Init.ClockDivision=TIM_CLOCKDIVISION_DIV1; 
TIM4_Handler.Init.RepetitionCounter=0; 
HAL_TIM_Base_Init(&TIM4_Handler);

 

When I run code like above, UEV interrupt occure in 1 sec. This is normal

But when I change clock division  suc as TIM_CLOCKDIVISION_DIV4, this period is not affected. There is an UEV interrupt in 1 sec.

 

What is the problem?  (Note that my APB1/2 clock is 16MHZ)

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