I generated my code from STM32CubeMx and wanted to generate a update event every 1µs. I work with the internal clock at 48MHz, which should be with Prescaler:0 and Autoreload:47 result to 1µs. I use a STM32F030 with TrueStudio V.9.0.0
generated code
/* TIM17 init function */
static void MX_TIM17_Init(void)
{
LL_TIM_InitTypeDef TIM_InitStruct;
/* Peripheral clock enable */
LL_APB1_GRP2_EnableClock(LL_APB1_GRP2_PERIPH_TIM17);
/* TIM17 interrupt Init */
NVIC_SetPriority(TIM17_IRQn, 3);
NVIC_EnableIRQ(TIM17_IRQn);
TIM_InitStruct.Prescaler = 0;
TIM_InitStruct.CounterMode = LL_TIM_COUNTERMODE_UP;
TIM_InitStruct.Autoreload = 47;
TIM_InitStruct.ClockDivision = LL_TIM_CLOCKDIVISION_DIV1;
TIM_InitStruct.RepetitionCounter = 0;
LL_TIM_Init(TIM17, &TIM_InitStruct);
LL_TIM_EnableARRPreload(TIM17);
}
I added in my init:
LL_TIM_EnableIT_UPDATE(TIM17);
LL_TIM_EnableCounter(TIM17);
In the IRQ_Handler i toggle a PIN:
void TIM17_IRQHandler(void)
{
/* USER CODE BEGIN TIM17_IRQn 0 */
LL_GPIO_TogglePin(LED_D2_2_GPIO_Port,LED_D2_2_Pin);
/* USER CODE END TIM17_IRQn 0 */
/* USER CODE BEGIN TIM17_IRQn 1 */
/* USER CODE END TIM17_IRQn 1 */
}
After flashing my device with the code it generates a Signal with Frequency 889kHz with Pulsewidth of 564ns measured with Oscilloscope. Changes on Prescaler or Autoreload does not affect this output, it stays right away at T_Pulse=564ns or F=889kHz. Any idea what I am missing here?
Register output from debugging:
CR1:0x81 CR2:0
DIER:0x01 SR:0x03
CCMR1_O/I:0 CCER:0
PSC:0 ARR:0x2f
RCR:0 CCR1:0
BDTR:0 DCR:0
DMAR:0x81
The solution was the clearance of the FLAG UIE in TIM17->SR in the IRQ_Handler. I was stuck permanently in the IRQ routine.