FreeRTOS/Demo/CORTEX_STM32L152_IAR/system_and_ST_code/STM32L1xx_StdPeriph_Driver/src/stm32l1xx_usart.c

/**
  ******************************************************************************
  * @file    stm32l1xx_usart.c
  * @author  MCD Application Team
  * @version V1.0.0RC1
  * @date    07/02/2010
  * @brief   This file provides all the USART firmware functions.
  ******************************************************************************
  * @copy
  *
  * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
  * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
  * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
  * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
  * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
  * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
  *
  * <h2><center>&copy; COPYRIGHT 2010 STMicroelectronics</center></h2>
  */ 

/* Includes ------------------------------------------------------------------*/
#include "stm32l1xx_usart.h"
#include "stm32l1xx_rcc.h"

/** @addtogroup STM32L1xx_StdPeriph_Driver
  * @{
  */

/** @defgroup USART 
  * @brief USART driver modules
  * @{
  */

/** @defgroup USART_Private_TypesDefinitions
  * @{
  */

/**
  * @}
  */

/** @defgroup USART_Private_Defines
  * @{
  */

/*!< USART CR1 register clear Mask ((~(uint16_t)0xE9F3)) */
#define CR1_CLEAR_MASK            ((uint16_t)(USART_CR1_M | USART_CR1_PCE | \
                                              USART_CR1_PS | USART_CR1_TE | \
                                              USART_CR1_RE))

/*!< USART CR2 register clock bits clear Mask ((~(uint16_t)0xF0FF)) */
#define CR2_CLOCK_CLEAR_MASK      ((uint16_t)(USART_CR2_CLKEN | USART_CR2_CPOL | \
                                              USART_CR2_CPHA | USART_CR2_LBCL))

/*!< USART CR3 register clear Mask ((~(uint16_t)0xFCFF)) */
#define CR3_CLEAR_MASK            ((uint16_t)(USART_CR3_RTSE | USART_CR3_CTSE))

/*!< USART Interrupts mask */
#define IT_MASK                   ((uint16_t)0x001F)

/**
  * @}
  */

/** @defgroup USART_Private_Macros
  * @{
  */

/**
  * @}
  */

/** @defgroup USART_Private_Variables
  * @{
  */

/**
  * @}
  */

/** @defgroup USART_Private_FunctionPrototypes
  * @{
  */

/**
  * @}
  */

/** @defgroup USART_Private_Functions
  * @{
  */

/**
  * @brief  Deinitializes the USARTx peripheral registers to their default reset values.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values: USART1, USART2 or USART3.
  * @retval None
  */
void USART_DeInit(USART_TypeDef* USARTx)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));

  if (USARTx == USART1)
  {
    RCC_APB2PeriphResetCmd(RCC_APB2Periph_USART1, ENABLE);
    RCC_APB2PeriphResetCmd(RCC_APB2Periph_USART1, DISABLE);
  }
  else if (USARTx == USART2)
  {
    RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2, ENABLE);
    RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2, DISABLE);
  }
  else 
  {
    if (USARTx == USART3)
    {
      RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART3, ENABLE);
      RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART3, DISABLE);    
    }
  }    
}

/**
  * @brief  Initializes the USARTx peripheral according to the specified
  *   parameters in the USART_InitStruct .
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_InitStruct: pointer to a USART_InitTypeDef structure
  *   that contains the configuration information for the specified USART peripheral.
  * @retval None
  */
void USART_Init(USART_TypeDef* USARTx, USART_InitTypeDef* USART_InitStruct)
{
  uint32_t tmpreg = 0x00, apbclock = 0x00;
  uint32_t integerdivider = 0x00;
  uint32_t fractionaldivider = 0x00;
  RCC_ClocksTypeDef RCC_ClocksStatus;

  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_BAUDRATE(USART_InitStruct->USART_BaudRate));  
  assert_param(IS_USART_WORD_LENGTH(USART_InitStruct->USART_WordLength));
  assert_param(IS_USART_STOPBITS(USART_InitStruct->USART_StopBits));
  assert_param(IS_USART_PARITY(USART_InitStruct->USART_Parity));
  assert_param(IS_USART_MODE(USART_InitStruct->USART_Mode));
  assert_param(IS_USART_HARDWARE_FLOW_CONTROL(USART_InitStruct->USART_HardwareFlowControl));
  
/*---------------------------- USART CR2 Configuration -----------------------*/
  tmpreg = USARTx->CR2;
  /* Clear STOP[13:12] bits */
  tmpreg &= (uint32_t)~((uint32_t)USART_CR2_STOP);

  /* Configure the USART Stop Bits, Clock, CPOL, CPHA and LastBit ------------*/
  /* Set STOP[13:12] bits according to USART_StopBits value */
  tmpreg |= (uint32_t)USART_InitStruct->USART_StopBits;
  
  /* Write to USART CR2 */
  USARTx->CR2 = (uint16_t)tmpreg;

/*---------------------------- USART CR1 Configuration -----------------------*/
  tmpreg = USARTx->CR1;
  /* Clear M, PCE, PS, TE and RE bits */
  tmpreg &= (uint32_t)~((uint32_t)CR1_CLEAR_MASK);

  /* Configure the USART Word Length, Parity and mode ----------------------- */
  /* Set the M bits according to USART_WordLength value */
  /* Set PCE and PS bits according to USART_Parity value */
  /* Set TE and RE bits according to USART_Mode value */
  tmpreg |= (uint32_t)USART_InitStruct->USART_WordLength | USART_InitStruct->USART_Parity |
            USART_InitStruct->USART_Mode;

  /* Write to USART CR1 */
  USARTx->CR1 = (uint16_t)tmpreg;

/*---------------------------- USART CR3 Configuration -----------------------*/  
  tmpreg = USARTx->CR3;
  /* Clear CTSE and RTSE bits */
  tmpreg &= (uint32_t)~((uint32_t)CR3_CLEAR_MASK);

  /* Configure the USART HFC -------------------------------------------------*/
  /* Set CTSE and RTSE bits according to USART_HardwareFlowControl value */
  tmpreg |= USART_InitStruct->USART_HardwareFlowControl;

  /* Write to USART CR3 */
  USARTx->CR3 = (uint16_t)tmpreg;

/*---------------------------- USART BRR Configuration -----------------------*/
  /* Configure the USART Baud Rate -------------------------------------------*/
  RCC_GetClocksFreq(&RCC_ClocksStatus);
  if (USARTx == USART1) 
  {
    apbclock = RCC_ClocksStatus.PCLK2_Frequency;
  }
  else
  {
    apbclock = RCC_ClocksStatus.PCLK1_Frequency;
  }

  /* Determine the integer part */
  if ((USARTx->CR1 & USART_CR1_OVER8) != 0)
  {
    /* Integer part computing in case Oversampling mode is 8 Samples */
    integerdivider = ((25 * apbclock) / (2 * (USART_InitStruct->USART_BaudRate)));    
  }
  else /* if ((USARTx->CR1 & CR1_OVER8_Set) == 0) */
  {
    /* Integer part computing in case Oversampling mode is 16 Samples */
    integerdivider = ((25 * apbclock) / (4 * (USART_InitStruct->USART_BaudRate)));    
  }
  tmpreg = (integerdivider / 100) << 4;

  /* Determine the fractional part */
  fractionaldivider = integerdivider - (100 * (tmpreg >> 4));

  /* Implement the fractional part in the register */
  if ((USARTx->CR1 & USART_CR1_OVER8) != 0)
  {
    tmpreg |= ((((fractionaldivider * 8) + 50) / 100)) & ((uint8_t)0x07);
  }
  else /* if ((USARTx->CR1 & CR1_OVER8_Set) == 0) */
  {
    tmpreg |= ((((fractionaldivider * 16) + 50) / 100)) & ((uint8_t)0x0F);
  }
 
  /* Write to USART BRR */
  USARTx->BRR = (uint16_t)tmpreg;
}

/**
  * @brief  Fills each USART_InitStruct member with its default value.
  * @param  USART_InitStruct: pointer to a USART_InitTypeDef structure
  *   which will be initialized.
  * @retval None
  */
void USART_StructInit(USART_InitTypeDef* USART_InitStruct)
{
  /* USART_InitStruct members default value */
  USART_InitStruct->USART_BaudRate = 9600;
  USART_InitStruct->USART_WordLength = USART_WordLength_8b;
  USART_InitStruct->USART_StopBits = USART_StopBits_1;
  USART_InitStruct->USART_Parity = USART_Parity_No ;
  USART_InitStruct->USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
  USART_InitStruct->USART_HardwareFlowControl = USART_HardwareFlowControl_None;  
}

/**
  * @brief  Initializes the USARTx peripheral Clock according to the 
  *   specified parameters in the USART_ClockInitStruct .
  * @param  USARTx: where x can be 1, 2, 3 to select the USART peripheral.
  * @param  USART_ClockInitStruct: pointer to a USART_ClockInitTypeDef
  *   structure that contains the configuration information for the specified 
  *   USART peripheral.  
  * @retval None
  */
void USART_ClockInit(USART_TypeDef* USARTx, USART_ClockInitTypeDef* USART_ClockInitStruct)
{
  uint32_t tmpreg = 0x00;
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_CLOCK(USART_ClockInitStruct->USART_Clock));
  assert_param(IS_USART_CPOL(USART_ClockInitStruct->USART_CPOL));
  assert_param(IS_USART_CPHA(USART_ClockInitStruct->USART_CPHA));
  assert_param(IS_USART_LASTBIT(USART_ClockInitStruct->USART_LastBit));
  
/*---------------------------- USART CR2 Configuration -----------------------*/
  tmpreg = USARTx->CR2;
  /* Clear CLKEN, CPOL, CPHA and LBCL bits */
  tmpreg &= (uint32_t)~((uint32_t)CR2_CLOCK_CLEAR_MASK);
  /* Configure the USART Clock, CPOL, CPHA and LastBit ------------*/
  /* Set CLKEN bit according to USART_Clock value */
  /* Set CPOL bit according to USART_CPOL value */
  /* Set CPHA bit according to USART_CPHA value */
  /* Set LBCL bit according to USART_LastBit value */
  tmpreg |= (uint32_t)USART_ClockInitStruct->USART_Clock | USART_ClockInitStruct->USART_CPOL | 
                 USART_ClockInitStruct->USART_CPHA | USART_ClockInitStruct->USART_LastBit;
  /* Write to USART CR2 */
  USARTx->CR2 = (uint16_t)tmpreg;
}

/**
  * @brief  Fills each USART_ClockInitStruct member with its default value.
  * @param  USART_ClockInitStruct: pointer to a USART_ClockInitTypeDef
  *   structure which will be initialized.
  * @retval None
  */
void USART_ClockStructInit(USART_ClockInitTypeDef* USART_ClockInitStruct)
{
  /* USART_ClockInitStruct members default value */
  USART_ClockInitStruct->USART_Clock = USART_Clock_Disable;
  USART_ClockInitStruct->USART_CPOL = USART_CPOL_Low;
  USART_ClockInitStruct->USART_CPHA = USART_CPHA_1Edge;
  USART_ClockInitStruct->USART_LastBit = USART_LastBit_Disable;
}

/**
  * @brief  Enables or disables the specified USART peripheral.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  NewState: new state of the USARTx peripheral.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void USART_Cmd(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 selected USART by setting the UE bit in the CR1 register */
    USARTx->CR1 |= USART_CR1_UE;
  }
  else
  {
    /* Disable the selected USART by clearing the UE bit in the CR1 register */
    USARTx->CR1 &= (uint16_t)~((uint16_t)USART_CR1_UE);
  }
}

/**
  * @brief  Enables or disables the specified USART interrupts.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_IT: specifies the USART interrupt sources to be enabled or disabled.
  *   This parameter can be one of the following values:
  *     @arg USART_IT_CTS:  CTS change interrupt (not available for UART4 and UART5)
  *     @arg USART_IT_LBD:  LIN Break detection interrupt
  *     @arg USART_IT_TXE:  Tansmit Data Register empty interrupt
  *     @arg USART_IT_TC:   Transmission complete interrupt
  *     @arg USART_IT_RXNE: Receive Data register not empty interrupt
  *     @arg USART_IT_IDLE: Idle line detection interrupt
  *     @arg USART_IT_PE:   Parity Error interrupt
  *     @arg USART_IT_ERR:  Error interrupt(Frame error, noise error, overrun error)
  * @param  NewState: new state of the specified USARTx interrupts.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void USART_ITConfig(USART_TypeDef* USARTx, uint16_t USART_IT, FunctionalState NewState)
{
  uint32_t usartreg = 0x00, itpos = 0x00, itmask = 0x00;
  uint32_t usartxbase = 0x00;
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_CONFIG_IT(USART_IT));
  assert_param(IS_FUNCTIONAL_STATE(NewState));
  
  usartxbase = (uint32_t)USARTx;

  /* Get the USART register index */
  usartreg = (((uint8_t)USART_IT) >> 0x05);

  /* Get the interrupt position */
  itpos = USART_IT & IT_MASK;
  itmask = (((uint32_t)0x01) << itpos);
    
  if (usartreg == 0x01) /* The IT is in CR1 register */
  {
    usartxbase += 0x0C;
  }
  else if (usartreg == 0x02) /* The IT is in CR2 register */
  {
    usartxbase += 0x10;
  }
  else /* The IT is in CR3 register */
  {
    usartxbase += 0x14; 
  }
  if (NewState != DISABLE)
  {
    *(__IO uint32_t*)usartxbase  |= itmask;
  }
  else
  {
    *(__IO uint32_t*)usartxbase &= ~itmask;
  }
}

/**
  * @brief  Enables or disables the USART’s DMA interface.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_DMAReq: specifies the DMA request.
  *   This parameter can be any combination of the following values:
  *     @arg USART_DMAReq_Tx: USART DMA transmit request
  *     @arg USART_DMAReq_Rx: USART DMA receive request
  * @param  NewState: new state of the DMA Request sources.
  *   This parameter can be: ENABLE or DISABLE.
  * @note The DMA mode is not available for UART5.  
  * @retval None
  */
void USART_DMACmd(USART_TypeDef* USARTx, uint16_t USART_DMAReq, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_DMAREQ(USART_DMAReq));  
  assert_param(IS_FUNCTIONAL_STATE(NewState)); 

  if (NewState != DISABLE)
  {
    /* Enable the DMA transfer for selected requests by setting the DMAT and/or
       DMAR bits in the USART CR3 register */
    USARTx->CR3 |= USART_DMAReq;
  }
  else
  {
    /* Disable the DMA transfer for selected requests by clearing the DMAT and/or
       DMAR bits in the USART CR3 register */
    USARTx->CR3 &= (uint16_t)~USART_DMAReq;
  }
}

/**
  * @brief  Sets the address of the USART node.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @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));
  assert_param(IS_USART_ADDRESS(USART_Address)); 
    
  /* Clear the USART address */
  USARTx->CR2 &= (uint16_t)~((uint16_t)USART_CR2_ADD);
  /* Set the USART address node */
  USARTx->CR2 |= USART_Address;
}

/**
  * @brief  Selects the USART WakeUp method.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @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_WakeUpConfig(USART_TypeDef* USARTx, uint16_t USART_WakeUp)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_WAKEUP(USART_WakeUp));
  
  USARTx->CR1 &= (uint16_t)~((uint16_t)USART_CR1_WAKE);
  USARTx->CR1 |= USART_WakeUp;
}

/**
  * @brief  Determines if the USART is in mute mode or not.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  NewState: new state of the USART mute mode.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void USART_ReceiverWakeUpCmd(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 RWU bit in the CR1 register */
    USARTx->CR1 |= USART_CR1_RWU;
  }
  else
  {
    /* Disable the USART mute mode by clearing the RWU bit in the CR1 register */
    USARTx->CR1 &= (uint16_t)~((uint16_t)USART_CR1_RWU);
  }
}

/**
  * @brief  Sets the USART LIN Break detection length.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_LINBreakDetectLength: specifies the LIN break detection length.
  *   This parameter can be one of the following values:
  *     @arg USART_LINBreakDetectLength_10b: 10-bit break detection
  *     @arg USART_LINBreakDetectLength_11b: 11-bit break detection
  * @retval None
  */
void USART_LINBreakDetectLengthConfig(USART_TypeDef* USARTx, uint16_t USART_LINBreakDetectLength)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_LIN_BREAK_DETECT_LENGTH(USART_LINBreakDetectLength));
  
  USARTx->CR2 &= (uint16_t)~((uint16_t)USART_CR2_LBDL);
  USARTx->CR2 |= USART_LINBreakDetectLength;  
}

/**
  * @brief  Enables or disables the USART’s LIN mode.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  NewState: new state of the USART LIN mode.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void USART_LINCmd(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 LIN mode by setting the LINEN bit in the CR2 register */
    USARTx->CR2 |= USART_CR2_LINEN;
  }
  else
  {
    /* Disable the LIN mode by clearing the LINEN bit in the CR2 register */
    USARTx->CR2 &= (uint16_t)~((uint16_t)USART_CR2_LINEN);
  }
}

/**
  * @brief  Transmits single data through the USARTx peripheral.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @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->DR = (Data & (uint16_t)0x01FF);
}

/**
  * @brief  Returns the most recent received data by the USARTx peripheral.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @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->DR & (uint16_t)0x01FF);
}

/**
  * @brief  Transmits break characters.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @retval None
  */
void USART_SendBreak(USART_TypeDef* USARTx)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  
  /* Send break characters */
  USARTx->CR1 |= USART_CR1_SBK;
}

/**
  * @brief  Sets the specified USART guard time.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_GuardTime: specifies the guard time.
  * @note The guard time bits are not available for UART4 and UART5.   
  * @retval None
  */
void USART_SetGuardTime(USART_TypeDef* USARTx, uint8_t USART_GuardTime)
{    
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  
  /* Clear the USART Guard time */
  USARTx->GTPR &= USART_GTPR_PSC;
  /* Set the USART guard time */
  USARTx->GTPR |= (uint16_t)((uint16_t)USART_GuardTime << 0x08);
}

/**
  * @brief  Sets the system clock prescaler.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_Prescaler: specifies the prescaler clock.  
  * @note   The function is used for IrDA mode with UART4 and UART5.
  * @retval None
  */
void USART_SetPrescaler(USART_TypeDef* USARTx, uint8_t USART_Prescaler)
{ 
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  
  /* Clear the USART prescaler */
  USARTx->GTPR &= USART_GTPR_GT;
  /* Set the USART prescaler */
  USARTx->GTPR |= USART_Prescaler;
}

/**
  * @brief  Enables or disables the USART’s Smart Card mode.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  NewState: new state of the Smart Card mode.
  *   This parameter can be: ENABLE or DISABLE.     
  * @note The Smart Card mode is not available for UART4 and UART5. 
  * @retval None
  */
void USART_SmartCardCmd(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 SC mode by setting the SCEN bit in the CR3 register */
    USARTx->CR3 |= USART_CR3_SCEN;
  }
  else
  {
    /* Disable the SC mode by clearing the SCEN bit in the CR3 register */
    USARTx->CR3 &= (uint16_t)~((uint16_t)USART_CR3_SCEN);
  }
}

/**
  * @brief  Enables or disables NACK transmission.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  NewState: new state of the NACK transmission.
  *   This parameter can be: ENABLE or DISABLE.  
  * @note The Smart Card mode is not available for UART4 and UART5.
  * @retval None
  */
void USART_SmartCardNACKCmd(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 NACK transmission by setting the NACK bit in the CR3 register */
    USARTx->CR3 |= USART_CR3_NACK;
  }
  else
  {
    /* Disable the NACK transmission by clearing the NACK bit in the CR3 register */
    USARTx->CR3 &= (uint16_t)~((uint16_t)USART_CR3_NACK);
  }
}

/**
  * @brief  Enables or disables the USART’s Half Duplex communication.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  NewState: new state of the USART Communication.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void USART_HalfDuplexCmd(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 Half-Duplex mode by setting the HDSEL bit in the CR3 register */
    USARTx->CR3 |= USART_CR3_HDSEL;
  }
  else
  {
    /* Disable the Half-Duplex mode by clearing the HDSEL bit in the CR3 register */
    USARTx->CR3 &= (uint16_t)~((uint16_t)USART_CR3_HDSEL);
  }
}

/**
  * @brief  Enables or disables the USART's 8x oversampling mode.
  * @param USARTx: Select the USART or the UART peripheral. 
  *   This parameter can be one of the following values:
  *     USART1, USART2, USART3.
  * @param NewState: new state of the USART 8x oversampling mode.
  *   This parameter can be: ENABLE or DISABLE.
  *
  * @note
  *   This function has to be called before calling USART_Init()
  *   function in order to have correct baudrate Divider value.
  * @retval : None
  */
void USART_OverSampling8Cmd(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 8x Oversampling mode by setting the OVER8 bit in the CR1 register */
    USARTx->CR1 |= USART_CR1_OVER8;
  }
  else
  {
    /* Disable the 8x Oversampling mode by clearing the OVER8 bit in the CR1 register */
    USARTx->CR1 &= (uint16_t)~((uint16_t)USART_CR1_OVER8);
  }
}  

/**
  * @brief  Enables or disables the USART's one bit sampling methode.
  * @param USARTx: Select the USART or the UART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2, USART3.
  * @param NewState: new state of the USART one bit sampling methode.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval : None
  */
void USART_OneBitMethodCmd(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 one bit method by setting the ONEBITE bit in the CR3 register */
    USARTx->CR3 |= USART_CR3_ONEBIT;
  }
  else
  {
    /* Disable tthe one bit method by clearing the ONEBITE bit in the CR3 register */
    USARTx->CR3 &= (uint16_t)~((uint16_t)USART_CR3_ONEBIT);
  }
}

/**
  * @brief  Configures the USART’s IrDA interface.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_IrDAMode: specifies the IrDA mode.
  *   This parameter can be one of the following values:
  *     @arg USART_IrDAMode_LowPower
  *     @arg USART_IrDAMode_Normal
  * @retval None
  */
void USART_IrDAConfig(USART_TypeDef* USARTx, uint16_t USART_IrDAMode)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_IRDA_MODE(USART_IrDAMode));
    
  USARTx->CR3 &= (uint16_t)~((uint16_t)USART_CR3_IRLP);
  USARTx->CR3 |= USART_IrDAMode;
}

/**
  * @brief  Enables or disables the USART’s IrDA interface.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  NewState: new state of the IrDA mode.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void USART_IrDACmd(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 IrDA mode by setting the IREN bit in the CR3 register */
    USARTx->CR3 |= USART_CR3_IREN;
  }
  else
  {
    /* Disable the IrDA mode by clearing the IREN bit in the CR3 register */
    USARTx->CR3 &= (uint16_t)~((uint16_t)USART_CR3_IREN);
  }
}

/**
  * @brief  Checks whether the specified USART flag is set or not.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_FLAG: specifies the flag to check.
  *   This parameter can be one of the following values:
  *     @arg USART_FLAG_CTS:  CTS Change flag
  *     @arg USART_FLAG_LBD:  LIN Break detection flag
  *     @arg USART_FLAG_TXE:  Transmit data register empty flag
  *     @arg USART_FLAG_TC:   Transmission Complete flag
  *     @arg USART_FLAG_RXNE: Receive data register not empty flag
  *     @arg USART_FLAG_IDLE: Idle Line detection flag
  *     @arg USART_FLAG_ORE:  OverRun Error flag
  *     @arg USART_FLAG_NE:   Noise Error flag
  *     @arg USART_FLAG_FE:   Framing Error flag
  *     @arg USART_FLAG_PE:   Parity Error flag
  * @retval The new state of USART_FLAG (SET or RESET).
  */
FlagStatus USART_GetFlagStatus(USART_TypeDef* USARTx, uint16_t USART_FLAG)
{
  FlagStatus bitstatus = RESET;
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_FLAG(USART_FLAG));
  
  if ((USARTx->SR & USART_FLAG) != (uint16_t)RESET)
  {
    bitstatus = SET;
  }
  else
  {
    bitstatus = RESET;
  }
  return bitstatus;
}

/**
  * @brief  Clears the USARTx's pending flags.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_FLAG: specifies the flag to clear.
  *   This parameter can be any combination of the following values:
  *     @arg USART_FLAG_CTS:  CTS Change flag.
  *     @arg USART_FLAG_LBD:  LIN Break detection flag.
  *     @arg USART_FLAG_TC:   Transmission Complete flag.
  *     @arg USART_FLAG_RXNE: Receive data register not empty flag.
  *   
  * @note
  *   - PE (Parity error), FE (Framing error), NE (Noise error), ORE (OverRun 
  *     error) and IDLE (Idle line detected) flags are cleared by software 
  *     sequence: a read operation to USART_SR register (USART_GetFlagStatus()) 
  *     followed by a read operation to USART_DR register (USART_ReceiveData()).
  *   - RXNE flag can be also cleared by a read to the USART_DR register 
  *     (USART_ReceiveData()).
  *   - TC flag can be also cleared by software sequence: a read operation to 
  *     USART_SR register (USART_GetFlagStatus()) followed by a write operation
  *     to USART_DR register (USART_SendData()).
  *   - TXE flag is cleared only by a write to the USART_DR register 
  *     (USART_SendData()).
  * @retval None
  */
void USART_ClearFlag(USART_TypeDef* USARTx, uint16_t USART_FLAG)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_CLEAR_FLAG(USART_FLAG));
     
  USARTx->SR = (uint16_t)~USART_FLAG;
}

/**
  * @brief  Checks whether the specified USART interrupt has occurred or not.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_IT: specifies the USART interrupt source to check.
  *   This parameter can be one of the following values:
  *     @arg USART_IT_CTS:  CTS change interrupt
  *     @arg USART_IT_LBD:  LIN Break detection interrupt
  *     @arg USART_IT_TXE:  Tansmit Data Register empty interrupt
  *     @arg USART_IT_TC:   Transmission complete interrupt
  *     @arg USART_IT_RXNE: Receive Data register not empty interrupt
  *     @arg USART_IT_IDLE: Idle line detection interrupt
  *     @arg USART_IT_ORE:  OverRun Error interrupt
  *     @arg USART_IT_NE:   Noise Error interrupt
  *     @arg USART_IT_FE:   Framing Error interrupt
  *     @arg USART_IT_PE:   Parity Error interrupt
  * @retval The new state of USART_IT (SET or RESET).
  */
ITStatus USART_GetITStatus(USART_TypeDef* USARTx, uint16_t USART_IT)
{
  uint32_t bitpos = 0x00, itmask = 0x00, usartreg = 0x00;
  ITStatus bitstatus = RESET;
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_GET_IT(USART_IT)); 
  
  /* Get the USART register index */
  usartreg = (((uint8_t)USART_IT) >> 0x05);
  /* Get the interrupt position */
  itmask = USART_IT & IT_MASK;
  itmask = (uint32_t)0x01 << itmask;
  
  if (usartreg == 0x01) /* The IT  is in CR1 register */
  {
    itmask &= USARTx->CR1;
  }
  else if (usartreg == 0x02) /* The IT  is in CR2 register */
  {
    itmask &= USARTx->CR2;
  }
  else /* The IT  is in CR3 register */
  {
    itmask &= USARTx->CR3;
  }
  
  bitpos = USART_IT >> 0x08;
  bitpos = (uint32_t)0x01 << bitpos;
  bitpos &= USARTx->SR;
  if ((itmask != (uint16_t)RESET)&&(bitpos != (uint16_t)RESET))
  {
    bitstatus = SET;
  }
  else
  {
    bitstatus = RESET;
  }
  
  return bitstatus;  
}

/**
  * @brief  Clears the USARTx’s interrupt pending bits.
  * @param  USARTx: Select the USART peripheral. 
  *   This parameter can be one of the following values:
  *   USART1, USART2 or USART3.
  * @param  USART_IT: specifies the interrupt pending bit to clear.
  *   This parameter can be one of the following values:
  *     @arg USART_IT_CTS:  CTS change interrupt
  *     @arg USART_IT_LBD:  LIN Break detection interrupt
  *     @arg USART_IT_TC:   Transmission complete interrupt. 
  *     @arg USART_IT_RXNE: Receive Data register not empty interrupt.
  *   
  * @note
  *   - PE (Parity error), FE (Framing error), NE (Noise error), ORE (OverRun 
  *     error) and IDLE (Idle line detected) pending bits are cleared by 
  *     software sequence: a read operation to USART_SR register 
  *     (USART_GetITStatus()) followed by a read operation to USART_DR register 
  *     (USART_ReceiveData()).
  *   - RXNE pending bit can be also cleared by a read to the USART_DR register 
  *     (USART_ReceiveData()).
  *   - TC pending bit can be also cleared by software sequence: a read 
  *     operation to USART_SR register (USART_GetITStatus()) followed by a write 
  *     operation to USART_DR register (USART_SendData()).
  *   - TXE pending bit is cleared only by a write to the USART_DR register 
  *     (USART_SendData()).
  * @retval None
  */
void USART_ClearITPendingBit(USART_TypeDef* USARTx, uint16_t USART_IT)
{
  uint16_t bitpos = 0x00, itmask = 0x00;
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_CLEAR_IT(USART_IT)); 
  
  bitpos = USART_IT >> 0x08;
  itmask = ((uint16_t)0x01 << (uint16_t)bitpos);
  USARTx->SR = (uint16_t)~itmask;
}

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

/******************* (C) COPYRIGHT 2010 STMicroelectronics *****END OF FILE****/