Posted on July 06, 2018 at 12:24I created a new project (using CubeMx & Atollic TrueStudio) for STM32F103RB and tried to toggle a bit as quick as possible; I use TIMER2 and this function to initialize it:
=======================
/* TIM2 init function */
static void MX_TIM2_Init(void)
{
TIM_ClockConfigTypeDef sClockSourceConfig;
TIM_MasterConfigTypeDef sMasterConfig;
htim2.Instance = TIM2;
htim2.Init.Prescaler = 0;
htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
//htim2.Init.Period = 35; //72,000,000 / 36 => 0.5 usec
htim2.Init.Period = 35999; //72,000,000 / 36,000 => 0.5 msec
htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
}
=======================
The ISR for TIMER2 looks like this:
=======================
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
if (htim->Instance == TIM2)
{
HAL_GPIO_TogglePin(GPIOC, GPIO_PIN_9);
}
}
=======================
The clocks & GPIO are correctly initialized (IMO).
With this configuration I can go down to 5 usec but not to 0.5 usec (htim2.Init.Period = 35;).
What am I doing wrong?
I also have to mention that I can successfully generate an interrupt every 0.5 usec (with TIMER2) with a different compiler (MikroeC) with the same hardware and project settings. The only difference is that with MikroeC one has to program the registers (very low) because there is no HAL available for their compilers.
Is this because of the HAL implementation or am I missing something important?
Regards,
Radu G.
