Needed LPTIMER valid reinitialize sequence

[npatil15]

Hello,

I have problem statement, in which I have to re-Initialize lptimer for different timer value, as per current scenario, I have

Clock: 32Khz (LSI)

Divisor = 128

Period: Any time as per dynamic input.

 

So I want information about how I can safely reset the lptimer and then again re-init for different timer. Here is the reference lptimer code. where

/* uint32_t effectiveFreq = 32000/ 128; // 250 Hz
 uint32_t tickTimeInMS = 1000 / effectiveFreq; // 4 ms*/
#define TICK_TIME_IN_MS 4
void ReInit_LPTIM1(uint32_t timerInMS)
{
 /*lptimer reset block start*/
 HAL_LPTIM_IC_Stop_IT(&hlptim1, LPTIM_CHANNEL_1);

 __HAL_LPTIM_DISABLE(&hlptim1);

 if (HAL_LPTIM_DeInit(&hlptim1) != HAL_OK)
 {
 Error_Handler();
 }

 __HAL_RCC_LPTIM1_FORCE_RESET();
 __HAL_RCC_LPTIM1_RELEASE_RESET();
 /*lptimer reset block end*/
 LPTIM_OC_ConfigTypeDef sConfig1 = {0};

 hlptim1.Instance = LPTIM1;
 hlptim1.Init.Clock.Source = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC;
 hlptim1.Init.Clock.Prescaler = LPTIM_PRESCALER_DIV128;
 hlptim1.Init.Trigger.Source = LPTIM_TRIGSOURCE_SOFTWARE;
 hlptim1.Init.UpdateMode = LPTIM_UPDATE_IMMEDIATE;
 hlptim1.Init.CounterSource = LPTIM_COUNTERSOURCE_INTERNAL;
 hlptim1.Init.Input1Source = LPTIM_INPUT1SOURCE_GPIO;
 hlptim1.Init.Input2Source = LPTIM_INPUT2SOURCE_GPIO;
 hlptim1.Init.RepetitionCounter = 0;

 hlptim1.Init.Period = timerInMS/TICK_TIME_IN_MS - 1 ;

 if (HAL_LPTIM_Init(&hlptim1) != HAL_OK)
 {
 Error_Handler();
 }
 sConfig1.Pulse = hlptim1.Init.Period;
 sConfig1.OCPolarity = LPTIM_OCPOLARITY_HIGH;
 if (HAL_LPTIM_OC_ConfigChannel(&hlptim1, &sConfig1, LPTIM_CHANNEL_1) != HAL_OK)
 {
 Error_Handler();
 }

 __HAL_LPTIM_ENABLE_IT(&hlptim1, LPTIM_IT_CC1);
 HAL_LPTIM_IC_Start_IT(&hlptim1, LPTIM_CHANNEL_1);
}

Here, adding reset block is not working correctly, and if we remove this reset block then it works fine. But I want it should be clear/reset before re-initialize for safe working for longer run.

Thanks

Nitin 

 

[ahsrabrifat]

 

Here’s a modified ReInit_LPTIM1() approach that should work more reliably and be safe for long-term use without hard-resetting the peripheral at the RCC level:

 

 

void ReInit_LPTIM1(uint32_t timerInMS)
{
 // Step 1: Disable LPTIM and stop channel
 __HAL_LPTIM_DISABLE(&hlptim1);
 HAL_LPTIM_IC_Stop_IT(&hlptim1, LPTIM_CHANNEL_1);
 
 // Step 2: Disable interrupt
 __HAL_LPTIM_DISABLE_IT(&hlptim1, LPTIM_IT_CC1);
 
 // Step 3: DeInit peripheral
 if (HAL_LPTIM_DeInit(&hlptim1) != HAL_OK)
 {
 Error_Handler();
 }

 // Step 4: Reconfigure peripheral without RCC force-reset
 LPTIM_OC_ConfigTypeDef sConfig1 = {0};

 hlptim1.Instance = LPTIM1;
 hlptim1.Init.Clock.Source = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC;
 hlptim1.Init.Clock.Prescaler = LPTIM_PRESCALER_DIV128;
 hlptim1.Init.Trigger.Source = LPTIM_TRIGSOURCE_SOFTWARE;
 hlptim1.Init.UpdateMode = LPTIM_UPDATE_IMMEDIATE;
 hlptim1.Init.CounterSource = LPTIM_COUNTERSOURCE_INTERNAL;
 hlptim1.Init.Input1Source = LPTIM_INPUT1SOURCE_GPIO;
 hlptim1.Init.Input2Source = LPTIM_INPUT2SOURCE_GPIO;
 hlptim1.Init.RepetitionCounter = 0;

 // Step 5: Calculate and set new period
 hlptim1.Init.Period = timerInMS / TICK_TIME_IN_MS - 1;

 if (HAL_LPTIM_Init(&hlptim1) != HAL_OK)
 {
 Error_Handler();
 }

 sConfig1.Pulse = hlptim1.Init.Period;
 sConfig1.OCPolarity = LPTIM_OCPOLARITY_HIGH;

 if (HAL_LPTIM_OC_ConfigChannel(&hlptim1, &sConfig1, LPTIM_CHANNEL_1) != HAL_OK)
 {
 Error_Handler();
 }

 // Step 6: Re-enable interrupt and start again
 __HAL_LPTIM_ENABLE_IT(&hlptim1, LPTIM_IT_CC1);
 HAL_LPTIM_IC_Start_IT(&hlptim1, LPTIM_CHANNEL_1);
}