Posted on April 02, 2013 at 11:30
Good morning,
I have a STM32W rfckit 950 REV-A.
I' m using the STM32W108xx_SimpleMAC_V2.0.1 library.
I' d like to use a timer to switch a LED with a frequency of 1 Hz.
I' m using an interrupt service routine which should start at the timer update event.
This is my configuration:
void Timer2_Configuration()
{
TIM_TimeBaseInitTypeDef timer_2;
TIM_DeInit(TIM2);
TIM_TimeBaseStructInit(&timer_2);
timer_2.TIM_CounterMode=TIM_CounterMode_Down;
timer_2.TIM_Prescaler = 13;
timer_2.TIM_Period=1465;
TIM_TimeBaseInit(TIM2,&timer_2);
TIM_ITConfig(TIM2_IT,TIM_IT_Update,ENABLE);
TIM_Cmd(TIM2, ENABLE);
return;
}
void Interrupt_Configuration()
{
NVIC_InitTypeDef timer_2_irq;
timer_2_irq.NVIC_IRQChannel=TIM2_IRQn;
timer_2_irq.NVIC_IRQChannelCmd=ENABLE;
NVIC_Init(&timer_2_irq);
return;
}
Here the interrupt function:
void TIM2_IRQHandler ()
{
STM_EVAL_LEDToggle(LED1);
TIM_ClearITPendingBit(TIM2_IT,TIM_IT_Update); // not work
}
I noticed that, as soon as the timer gets to 0, many of the pending interrupt register bits are set (I was expecting only the UIF).
Then, the function
TIM_ClearITPendingBit
doesn't work properly because itdoesn't clear all ISR registerbits (it clears just one at a time, while the others get set at each function call).
I found this turnaround is currently working:
void TIM2_IRQHandler ()
{
STM_EVAL_LEDToggle(LED1);
TIM2_IT->ISR = 0x1f;
}
I have 2 questions:
1)Why do I have to write1s to get0s in the register?
2) Is this the best way to do it, oram I missing something in the configuration of timer and interrupts?
Thank you and regards.
