stm32f0xx_usart.c

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  * @retval None
  */
void USART_SetPrescaler(USART_TypeDef* USARTx, uint8_t USART_Prescaler)
{ 
  /* Check the parameters */
  assert_param(IS_USART_1_PERIPH(USARTx));
  
  /* Clear the USART prescaler */
  USARTx->GTPR &= USART_GTPR_GT;
  /* Set the USART prescaler */
  USARTx->GTPR |= USART_Prescaler;
}

/**
  * @}
  */


/** @defgroup USART_Group2 STOP Mode functions
 *  @brief   STOP Mode functions
 *
@verbatim
 ===============================================================================
                        ##### STOP Mode functions #####
 ===============================================================================
    [..] This subsection provides a set of functions allowing to manage 
         WakeUp from STOP mode.

    [..] The USART is able to WakeUp from Stop Mode if USART clock is set to HSI
         or LSI.
         
    [..] The WakeUp source is configured by calling USART_StopModeWakeUpSourceConfig()
         function.
         
    [..] After configuring the source of WakeUp and before entering in Stop Mode 
         USART_STOPModeCmd() function should be called to allow USART WakeUp.
                           
@endverbatim
  * @{
  */

/**
  * @brief  Enables or disables the specified USART peripheral in STOP Mode.
  * @param  USARTx: where x can be 1 to select the USART peripheral.
  * @param  NewState: new state of the USARTx peripheral state in stop mode.
  *   This parameter can be: ENABLE or DISABLE.
  * @note
  *   This function has to be called when USART clock is set to HSI or LSE. 
  * @retval None
  */
void USART_STOPModeCmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_USART_1_PERIPH(USARTx));
  assert_param(IS_FUNCTIONAL_STATE(NewState));
  
  if (NewState != DISABLE)
  {
    /* Enable the selected USART in STOP mode by setting the UESM bit in the CR1
       register */
    USARTx->CR1 |= USART_CR1_UESM;
  }
  else
  {
    /* Disable the selected USART in STOP mode by clearing the UE bit in the CR1
       register */
    USARTx->CR1 &= (uint32_t)~((uint32_t)USART_CR1_UESM);
  }
}

/**
  * @brief  Selects the USART WakeUp method form stop mode.
  * @param  USARTx: where x can be 1 to select the USART peripheral.
  * @param  USART_WakeUp: specifies the selected USART wakeup method.
  *   This parameter can be one of the following values:
  *     @arg USART_WakeUpSource_AddressMatch: WUF active on address match.
  *     @arg USART_WakeUpSource_StartBit: WUF active on Start bit detection.
  *     @arg USART_WakeUpSource_RXNE: WUF active on RXNE.
  * @note
  *   This function has to be called before calling USART_Cmd() function.   
  * @retval None
  */
void USART_StopModeWakeUpSourceConfig(USART_TypeDef* USARTx, uint32_t USART_WakeUpSource)
{
  /* Check the parameters */
  assert_param(IS_USART_1_PERIPH(USARTx));
  assert_param(IS_USART_STOPMODE_WAKEUPSOURCE(USART_WakeUpSource));

  USARTx->CR3 &= (uint32_t)~((uint32_t)USART_CR3_WUS);
  USARTx->CR3 |= USART_WakeUpSource;
}

/**
  * @}
  */


/** @defgroup USART_Group3 AutoBaudRate functions
 *  @brief   AutoBaudRate functions 
 *
@verbatim
 ===============================================================================
                       ##### AutoBaudRate functions #####
 ===============================================================================
    [..] This subsection provides a set of functions allowing to manage 
         the AutoBaudRate detections.
         
    [..] Before Enabling AutoBaudRate detection using USART_AutoBaudRateCmd ()
         The character patterns used to calculate baudrate must be chosen by calling 
         USART_AutoBaudRateConfig() function. These function take as parameter :
        (#)USART_AutoBaudRate_StartBit : any character starting with a bit 1.
        (#)USART_AutoBaudRate_FallingEdge : any character starting with a 10xx bit pattern. 
                          
    [..] At any later time, another request for AutoBaudRate detection can be performed
         using USART_AutoBaudRateNewRequest() function.
         
    [..] The AutoBaudRate detection is monitored by the status of ABRF flag which indicate
         that the AutoBaudRate detection is completed. In addition to ABRF flag, the ABRE flag
         indicate that this procedure is completed without success. USART_GetFlagStatus () 
         function should be used to monitor the status of these flags.  
             
@endverbatim
  * @{
  */

/**
  * @brief  Enables or disables the Auto Baud Rate.
  * @param  USARTx: where x can be 1 to select the USART peripheral.
  * @param NewState: new state of the USARTx auto baud rate.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void USART_AutoBaudRateCmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_USART_1_PERIPH(USARTx));
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable the auto baud rate feature by setting the ABREN bit in the CR2 
       register */
    USARTx->CR2 |= USART_CR2_ABREN;
  }
  else
  {
    /* Disable the auto baud rate feature by clearing the ABREN bit in the CR2 
       register */
    USARTx->CR2 &= (uint32_t)~((uint32_t)USART_CR2_ABREN);
  }
}

/**
  * @brief  Selects the USART auto baud rate method.
  * @param  USARTx: where x can be 1 to select the USART peripheral.
  * @param  USART_AutoBaudRate: specifies the selected USART auto baud rate method.
  *   This parameter can be one of the following values:
  *     @arg USART_AutoBaudRate_StartBit: Start Bit duration measurement.
  *     @arg USART_AutoBaudRate_FallingEdge: Falling edge to falling edge measurement.
  * @note
  *   This function has to be called before calling USART_Cmd() function.  
  * @retval None
  */
void USART_AutoBaudRateConfig(USART_TypeDef* USARTx, uint32_t USART_AutoBaudRate)
{
  /* Check the parameters */
  assert_param(IS_USART_1_PERIPH(USARTx));
  assert_param(IS_USART_AUTOBAUDRATE_MODE(USART_AutoBaudRate));

  USARTx->CR2 &= (uint32_t)~((uint32_t)USART_CR2_ABRMODE);
  USARTx->CR2 |= USART_AutoBaudRate;
}

/**
  * @brief  Requests a new AutoBaudRate detection.
  * @param  USARTx: where x can be 1 to select the USART peripheral.
  * @retval None
  */
void USART_AutoBaudRateNewRequest(USART_TypeDef* USARTx)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));

  USARTx->ISR &= (uint32_t)~((uint32_t)USART_FLAG_ABRF);
}

/**
  * @}
  */


/** @defgroup USART_Group4 Data transfers functions
 *  @brief   Data transfers functions 
 *
@verbatim   
 ===============================================================================
                    ##### Data transfers functions #####
 ===============================================================================
    [..] This subsection provides a set of functions allowing to manage 
         the USART data transfers.
    [..] During an USART reception, data shifts in least significant bit first 
         through the RX pin. When a transmission is taking place, a write instruction to 
         the USART_TDR register stores the data in the shift register.
    [..] The read access of the USART_RDR register can be done using 
         the USART_ReceiveData() function and returns the RDR value.
         Whereas a write access to the USART_TDR can be done using USART_SendData()
         function and stores the written data into TDR.

@endverbatim
  * @{
  */

/**
  * @brief  Transmits single data through the USARTx peripheral.
  * @param  USARTx: where x can be 1 or 2 to select the USART peripheral.
  * @param  Data: the data to transmit.
  * @retval None
  */
void USART_SendData(USART_TypeDef* USARTx, uint16_t Data)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_DATA(Data)); 
    
  /* Transmit Data */
  USARTx->TDR = (Data & (uint16_t)0x01FF);
}

/**
  * @brief  Returns the most recent received data by the USARTx peripheral.
  * @param  USARTx: where x can be 1 or 2 to select the USART peripheral.
  * @retval The received data.
  */
uint16_t USART_ReceiveData(USART_TypeDef* USARTx)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  
  /* Receive Data */
  return (uint16_t)(USARTx->RDR & (uint16_t)0x01FF);
}

/**
  * @}
  */

/** @defgroup USART_Group5 MultiProcessor Communication functions
 *  @brief   Multi-Processor Communication functions 
 *
@verbatim   
 ===============================================================================
             ##### Multi-Processor Communication functions #####
 ===============================================================================
    [..] This subsection provides a set of functions allowing to manage the USART
         multiprocessor communication.
    [..] For instance one of the USARTs can be the master, its TX output is
         connected to the RX input of the other USART. The others are slaves,
         their respective TX outputs are logically ANDed together and connected 
         to the RX input of the master. USART multiprocessor communication is 
         possible through the following procedure:
         (#) Program the Baud rate, Word length = 9 bits, Stop bits, Parity, 
             Mode transmitter or Mode receiver and hardware flow control values 
             using the USART_Init() function.
         (#) Configures the USART address using the USART_SetAddress() function.
         (#) Configures the wake up methode (USART_WakeUp_IdleLine or 
             USART_WakeUp_AddressMark) using USART_WakeUpConfig() function only 
             for the slaves.
         (#) Enable the USART using the USART_Cmd() function.
         (#) Enter the USART slaves in mute mode using USART_ReceiverWakeUpCmd() 
             function.
    [..] The USART Slave exit from mute mode when receive the wake up condition.

@endverbatim
  * @{
  */

/**
  * @brief  Sets the address of the USART node.
  * @param  USARTx: where x can be 1 or 2 to select the USART peripheral.
  * @param  USART_Address: Indicates the address of the USART node.
  * @retval None
  */
void USART_SetAddress(USART_TypeDef* USARTx, uint8_t USART_Address)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  
  /* Clear the USART address */
  USARTx->CR2 &= (uint32_t)~((uint32_t)USART_CR2_ADD);
  /* Set the USART address node */
  USARTx->CR2 |=((uint32_t)USART_Address << (uint32_t)0x18);
}

/**
  * @brief  Enables or disables the USART's mute mode.
  * @param  USARTx: where x can be 1 or 2 to select the USART peripheral.
  * @param  NewState: new state of the USART mute mode.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void USART_MuteModeCmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_FUNCTIONAL_STATE(NewState)); 
  
  if (NewState != DISABLE)
  {
    /* Enable the USART mute mode by setting the MME bit in the CR1 register */
    USARTx->CR1 |= USART_CR1_MME;
  }
  else
  {
    /* Disable the USART mute mode by clearing the MME bit in the CR1 register */
    USARTx->CR1 &= (uint32_t)~((uint32_t)USART_CR1_MME);
  }
}

/**
  * @brief  Selects the USART WakeUp method from mute mode.
  * @param  USARTx: where x can be 1 or 2 to select the USART peripheral.
  * @param  USART_WakeUp: specifies the USART wakeup method.
  *   This parameter can be one of the following values:
  *     @arg USART_WakeUp_IdleLine: WakeUp by an idle line detection
  *     @arg USART_WakeUp_AddressMark: WakeUp by an address mark
  * @retval None
  */
void USART_MuteModeWakeUpConfig(USART_TypeDef* USARTx, uint32_t USART_WakeUp)
{