I have a simple program where I am testing the internal clock of the STM32L010F4P6. I need to configure it to 32.768kHz due to power consumption requirements, as I need it to consume as little as possible. I configure the clock using MSI with SYSCLK=65.536kHz and AHB prescaler=2 to have an HCLK=32.768kHz. I also configure pin PA10 as an output to turn an LED on or off. In the main loop, I toggle the LED with a 100ms delay. I compile and run the program, but the result is that the LED does not change, i.e., it does not blink. However, if I change the AHB prescaler to 1 to have an HCLK=65.536kHz, compile and run, the LED blinks. This happens when I configure all the internal clocks and lower HCLK to 32.768kHz; the LED does not work. However, when I increase HCLK to 65.536kHz, the LED works. What could be happening? I have conducted many tests and have been trying to understand this behavior for some time.

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);

/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();

  /* USER CODE BEGIN 2 */
 
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */

  //  SysTick_Config(SystemCoreClock/1000);
  while (1)
  {
      HAL_GPIO_TogglePin(GPIOA,Led_Pin);
      HAL_Delay(100);
     

    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}


void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_MSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_DIV4;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
  RCC_OscInitStruct.MSICalibrationValue = 16;
  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_0;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV2;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV16;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV16;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }
}


static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  
  __HAL_RCC_GPIOA_CLK_ENABLE();
  
  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOA,Led_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pins : Pin Led_Pin */
  GPIO_InitStruct.Pin = Led_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);


}

I conducted tests with the different internal clocks because I don’t have an external clock, and I don’t have a pin available to place an external clock. The problem is that when I configure it to 32.768kHz and test to make the LED blink with a 100ms delay, the LED does not blink. However, when I increase the clock to 65.536kHz, the LED works and blinks.