STM32F103 timer interrupt fastest time is less than 1us?
I use STM32F103CB in my project. but I found timer interrupt fastest time can't less than 1us.
Timer prescaler is 0, up counter mode, counter period is 36, no inernal clock division and auto-reload enable. When timer interrupt occur. I set Pin high and low in turn. But the output time from the pin is 1us.
/* TIM2 init function */
void MX_TIM2_Init(void)
{
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
htim2.Instance = TIM2;
htim2.Init.Prescaler = 0;
htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
htim2.Init.Period = 36;
htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief This function handles TIM2 global interrupt.
*/
void TIM2_IRQHandler(void)
{
/* USER CODE BEGIN TIM2_IRQn 0 */
TIM2->SR &= ~(1 << 0);
static uint8_t bPin = 0;
bPin = !bPin;
if (bPin)
{
GPIOB->BSRR = 0x8000;
}
else
{
GPIOB->BSRR = 0x80000000;
}
/* USER CODE END TIM2_IRQn 0 */
/* USER CODE BEGIN TIM2_IRQn 1 */
/* USER CODE END TIM2_IRQn 1 */
}
