Code error when passing parameters to timer function

[treeset]

https://community.st.com/t5/stm32-mcus-products/can-pwm-settings-affect-other-timer-settings/m-p/748254#M267471

void TIM2_Configuration(u32 Intervalms)
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

	TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

	TIM_TimeBaseStructure.TIM_Prescaler   = 16000-1;

	//do not work
	//TIM_TimeBaseStructure.TIM_Period 	  = Intervalms - 1;

	//do work
	TIM_TimeBaseStructure.TIM_Period 	  = 500 - 1;
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

	TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
	TIM_Cmd(TIM2, ENABLE);

	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
	NVIC_InitTypeDef NVIC_InitStructure;

	NVIC_InitStructure.NVIC_IRQChannel 					 = TIM2_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority 		 = 1;
	NVIC_InitStructure.NVIC_IRQChannelCmd 				 = ENABLE;

	NVIC_Init(&NVIC_InitStructure);
}

 In the last article, I said that the code worked or did not work depending on the location of TIM2_Configuration. However, when I removed the parameter from TIM2_Configuration and changed the period initialization to 500-1, the code worked properly regardless of the order. Does anyone know what causes this phenomenon to occur?

[mƎALLEm · Accepted solution]

Check the value of 

TIM_TimeBaseStructure.TIM_Period 

after setting it:

TIM_TimeBaseStructure.TIM_Period 	  = Intervalms - 1;