Entering low power mode on STM32L0 to use USART1

I want to use as little power as possible by reading USART1 at 300 baud. 40 bytes. There are many other peripherals out there, but they don't need to run - all that needs to be run is RTC in parallel. The peripherals must be frozen and the RAM must be the same.

As I see it, the low power mode is the optimal mode (please correct me if I'm wrong here):

void HAL_PWREx_EnableLowPowerRunMode(void)
{
  /* Enters the Low Power Run mode */
  SET_BIT(PWR->CR, PWR_CR_LPSDSR);
  SET_BIT(PWR->CR, PWR_CR_LPRUN);
}

      

        
        
        
      

    

Now the clock configuration is currently

• System Clock Source = PLL (HSI)
• SYSCLK (Hz) = 32000000
• HCLK (Hz) = 32000000
• AHB Prescaler = 1
• APB1 Prescaler = 1
• APB2 Prescaler = 1
• HSI frequency (Hz) = 16000000
• PLLMUL = 6
• PLLDIV = 3
• Flash Delay (WS) = 1
• Power regulator voltage = SCALE 1

How can I enter this mode and restore it?

// Init?
HAL_PWREx_EnableLowPowerRunMode();
HAL_PWREx_DisableLowPowerRunMode();
// Deinit?

      

        
        
        
      

    

My attempt at initialization, what am I missing here?

void init_clock(){


  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_PeriphCLKInitTypeDef PeriphClkInit;

  /**Initializes the CPU, AHB and APB busses 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_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }
    /**Configure the main internal regulator output voltage 
    */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);

    /**Initializes the CPU, AHB and APB busses clocks 
    */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_MSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_DIV4;
  RCC_OscInitStruct.HSICalibrationValue = 16;
  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
  RCC_OscInitStruct.MSICalibrationValue = 0;
  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_0;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART1;
  PeriphClkInit.Usart1ClockSelection = RCC_USART1CLKSOURCE_SYSCLK;

  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
  {
    Error_Handler();
  }

}

      

        
        
        
      

    

• Deinit = Same as inital init clock config