Initialization and de-initialization functions

Functions
ErrorStatus	LL_LPUART_DeInit (USART_TypeDef *LPUARTx)
	De-initialize LPUART registers (Registers restored to their default values). More...
ErrorStatus	LL_LPUART_Init (USART_TypeDef *LPUARTx, LL_LPUART_InitTypeDef *LPUART_InitStruct)
	Initialize LPUART registers according to the specified parameters in LPUART_InitStruct. More...
void	LL_LPUART_StructInit (LL_LPUART_InitTypeDef *LPUART_InitStruct)
	Set each LL_LPUART_InitTypeDef field to default value. More...

Detailed Description

Function Documentation

LL_LPUART_DeInit()

ErrorStatus LL_LPUART_DeInit

(

USART_TypeDef *

LPUARTx

)

De-initialize LPUART registers (Registers restored to their default values).

Parameters

LPUARTx

LPUART Instance

Return values

An	ErrorStatus enumeration value: SUCCESS: LPUART registers are de-initialized ERROR: not applicable

Definition at line 132 of file stm32l4xx_ll_lpuart.c.

{
  ErrorStatus status = SUCCESS;

  /* Check the parameters */
  assert_param(IS_LPUART_INSTANCE(LPUARTx));

  if (LPUARTx == LPUART1)
  {
    /* Force reset of LPUART peripheral */
    LL_APB1_GRP2_ForceReset(LL_APB1_GRP2_PERIPH_LPUART1);

    /* Release reset of LPUART peripheral */
    LL_APB1_GRP2_ReleaseReset(LL_APB1_GRP2_PERIPH_LPUART1);
  }
  else
  {
    status = ERROR;
  }

  return (status);
}

LL_LPUART_Init()

ErrorStatus LL_LPUART_Init	(	USART_TypeDef *	LPUARTx,
		LL_LPUART_InitTypeDef *	LPUART_InitStruct
	)

Initialize LPUART registers according to the specified parameters in LPUART_InitStruct.

Note

As some bits in LPUART configuration registers can only be written when the LPUART is disabled (USART_CR1_UE bit =0), LPUART Peripheral should be in disabled state prior calling this function. Otherwise, ERROR result will be returned.

Baud rate value stored in LPUART_InitStruct BaudRate field, should be valid (different from 0).

Parameters

LPUARTx	LPUART Instance
LPUART_InitStruct	pointer to a LL_LPUART_InitTypeDef structure that contains the configuration information for the specified LPUART peripheral.

Return values

An	ErrorStatus enumeration value: SUCCESS: LPUART registers are initialized according to LPUART_InitStruct content ERROR: Problem occurred during LPUART Registers initialization

Definition at line 168 of file stm32l4xx_ll_lpuart.c.

{
  ErrorStatus status = ERROR;
  uint32_t periphclk;

  /* Check the parameters */
  assert_param(IS_LPUART_INSTANCE(LPUARTx));
#if defined(USART_PRESC_PRESCALER)
  assert_param(IS_LL_LPUART_PRESCALER(LPUART_InitStruct->PrescalerValue));
#endif /* USART_PRESC_PRESCALER */
  assert_param(IS_LL_LPUART_BAUDRATE(LPUART_InitStruct->BaudRate));
  assert_param(IS_LL_LPUART_DATAWIDTH(LPUART_InitStruct->DataWidth));
  assert_param(IS_LL_LPUART_STOPBITS(LPUART_InitStruct->StopBits));
  assert_param(IS_LL_LPUART_PARITY(LPUART_InitStruct->Parity));
  assert_param(IS_LL_LPUART_DIRECTION(LPUART_InitStruct->TransferDirection));
  assert_param(IS_LL_LPUART_HWCONTROL(LPUART_InitStruct->HardwareFlowControl));

  /* LPUART needs to be in disabled state, in order to be able to configure some bits in
     CRx registers. Otherwise (LPUART not in Disabled state) => return ERROR */
  if (LL_LPUART_IsEnabled(LPUARTx) == 0U)
  {
    /*---------------------------- LPUART CR1 Configuration -----------------------
     * Configure LPUARTx CR1 (LPUART Word Length, Parity and Transfer Direction bits) with parameters:
     * - DataWidth:          USART_CR1_M bits according to LPUART_InitStruct->DataWidth value
     * - Parity:             USART_CR1_PCE, USART_CR1_PS bits according to LPUART_InitStruct->Parity value
     * - TransferDirection:  USART_CR1_TE, USART_CR1_RE bits according to LPUART_InitStruct->TransferDirection value
     */
    MODIFY_REG(LPUARTx->CR1,
               (USART_CR1_M | USART_CR1_PCE | USART_CR1_PS | USART_CR1_TE | USART_CR1_RE),
               (LPUART_InitStruct->DataWidth | LPUART_InitStruct->Parity | LPUART_InitStruct->TransferDirection));

    /*---------------------------- LPUART CR2 Configuration -----------------------
     * Configure LPUARTx CR2 (Stop bits) with parameters:
     * - Stop Bits:          USART_CR2_STOP bits according to LPUART_InitStruct->StopBits value.
     */
    LL_LPUART_SetStopBitsLength(LPUARTx, LPUART_InitStruct->StopBits);

    /*---------------------------- LPUART CR3 Configuration -----------------------
     * Configure LPUARTx CR3 (Hardware Flow Control) with parameters:
     * - HardwareFlowControl: USART_CR3_RTSE, USART_CR3_CTSE bits according to LPUART_InitStruct->HardwareFlowControl value.
     */
    LL_LPUART_SetHWFlowCtrl(LPUARTx, LPUART_InitStruct->HardwareFlowControl);

    /*---------------------------- LPUART BRR Configuration -----------------------
     * Retrieve Clock frequency used for LPUART Peripheral
     */
    periphclk = LL_RCC_GetLPUARTClockFreq(LL_RCC_LPUART1_CLKSOURCE);

    /* Configure the LPUART Baud Rate :
    #if defined(USART_PRESC_PRESCALER)
       - prescaler value is required
    #endif
       - valid baud rate value (different from 0) is required
       - Peripheral clock as returned by RCC service, should be valid (different from 0).
    */
    if ((periphclk != LL_RCC_PERIPH_FREQUENCY_NO)
        && (LPUART_InitStruct->BaudRate != 0U))
    {
      status = SUCCESS;
      LL_LPUART_SetBaudRate(LPUARTx,
                            periphclk,
#if defined(USART_PRESC_PRESCALER)
                            LPUART_InitStruct->PrescalerValue,
#endif /* USART_PRESC_PRESCALER */
                            LPUART_InitStruct->BaudRate);

      /* Check BRR is greater than or equal to 0x300 */
      assert_param(IS_LL_LPUART_BRR_MIN(LPUARTx->BRR));

      /* Check BRR is lower than or equal to 0xFFFFF */
      assert_param(IS_LL_LPUART_BRR_MAX(LPUARTx->BRR));
    }

#if defined(USART_PRESC_PRESCALER)
    /*---------------------------- LPUART PRESC Configuration -----------------------
     * Configure LPUARTx PRESC (Prescaler) with parameters:
     * - PrescalerValue: LPUART_PRESC_PRESCALER bits according to LPUART_InitStruct->PrescalerValue value.
     */
    LL_LPUART_SetPrescaler(LPUARTx, LPUART_InitStruct->PrescalerValue);
#endif /* USART_PRESC_PRESCALER */
  }

  return (status);
}

LL_LPUART_StructInit()

void LL_LPUART_StructInit

(

LL_LPUART_InitTypeDef *

LPUART_InitStruct

)

Set each LL_LPUART_InitTypeDef field to default value.

Parameters

LPUART_InitStruct

pointer to a LL_LPUART_InitTypeDef structure whose fields will be set to default values.

Return values

None

Definition at line 260 of file stm32l4xx_ll_lpuart.c.

{
  /* Set LPUART_InitStruct fields to default values */
#if defined(USART_PRESC_PRESCALER)
  LPUART_InitStruct->PrescalerValue      = LL_LPUART_PRESCALER_DIV1;
#endif /* USART_PRESC_PRESCALER */
  LPUART_InitStruct->BaudRate            = 9600U;
  LPUART_InitStruct->DataWidth           = LL_LPUART_DATAWIDTH_8B;
  LPUART_InitStruct->StopBits            = LL_LPUART_STOPBITS_1;
  LPUART_InitStruct->Parity              = LL_LPUART_PARITY_NONE ;
  LPUART_InitStruct->TransferDirection   = LL_LPUART_DIRECTION_TX_RX;
  LPUART_InitStruct->HardwareFlowControl = LL_LPUART_HWCONTROL_NONE;
}