stm32f2xx_usart.c

STM32+Grlib

}

/**
  * @}
  */
  
/** @defgroup USART_Group9 Interrupts and flags management functions
 *  @brief   Interrupts and flags management functions 
 *
@verbatim   
 ===============================================================================
                   Interrupts and flags management functions
 ===============================================================================  

  This subsection provides a set of functions allowing to configure the USART 
  Interrupts sources, DMA channels requests and check or clear the flags or 
  pending bits status.
  The user should identify which mode will be used in his application to manage 
  the communication: Polling mode, Interrupt mode or DMA mode. 
    
  Polling Mode
  =============
  In Polling Mode, the SPI communication can be managed by 10 flags:
     1. USART_FLAG_TXE : to indicate the status of the transmit buffer register
     2. USART_FLAG_RXNE : to indicate the status of the receive buffer register
     3. USART_FLAG_TC : to indicate the status of the transmit operation
     4. USART_FLAG_IDLE : to indicate the status of the Idle Line             
     5. USART_FLAG_CTS : to indicate the status of the nCTS input
     6. USART_FLAG_LBD : to indicate the status of the LIN break detection
     7. USART_FLAG_NE : to indicate if a noise error occur
     8. USART_FLAG_FE : to indicate if a frame error occur
     9. USART_FLAG_PE : to indicate if a parity error occur
     10. USART_FLAG_ORE : to indicate if an Overrun error occur

  In this Mode it is advised to use the following functions:
      - FlagStatus USART_GetFlagStatus(USART_TypeDef* USARTx, uint16_t USART_FLAG);
      - void USART_ClearFlag(USART_TypeDef* USARTx, uint16_t USART_FLAG);

  Interrupt Mode
  ===============
  In Interrupt Mode, the USART communication can be managed by 8 interrupt sources
  and 10 pending bits: 

  Pending Bits:
  ------------- 
     1. USART_IT_TXE : to indicate the status of the transmit buffer register
     2. USART_IT_RXNE : to indicate the status of the receive buffer register
     3. USART_IT_TC : to indicate the status of the transmit operation
     4. USART_IT_IDLE : to indicate the status of the Idle Line             
     5. USART_IT_CTS : to indicate the status of the nCTS input
     6. USART_IT_LBD : to indicate the status of the LIN break detection
     7. USART_IT_NE : to indicate if a noise error occur
     8. USART_IT_FE : to indicate if a frame error occur
     9. USART_IT_PE : to indicate if a parity error occur
     10. USART_IT_ORE : to indicate if an Overrun error occur

  Interrupt Source:
  -----------------
     1. USART_IT_TXE : specifies the interrupt source for the Tx buffer empty 
                       interrupt. 
     2. USART_IT_RXNE : specifies the interrupt source for the Rx buffer not 
                        empty interrupt.
     3. USART_IT_TC : specifies the interrupt source for the Transmit complete 
                       interrupt. 
     4. USART_IT_IDLE : specifies the interrupt source for the Idle Line interrupt.             
     5. USART_IT_CTS : specifies the interrupt source for the CTS interrupt. 
     6. USART_IT_LBD : specifies the interrupt source for the LIN break detection
                       interrupt. 
     7. USART_IT_PE : specifies the interrupt source for the parity error interrupt. 
     8. USART_IT_ERR :  specifies the interrupt source for the errors interrupt.

@note Some parameters are coded in order to use them as interrupt source or as pending bits.

  In this Mode it is advised to use the following functions:
     - void USART_ITConfig(USART_TypeDef* USARTx, uint16_t USART_IT, FunctionalState NewState);
     - ITStatus USART_GetITStatus(USART_TypeDef* USARTx, uint16_t USART_IT);
     - void USART_ClearITPendingBit(USART_TypeDef* USARTx, uint16_t USART_IT);

  DMA Mode
  ========
  In DMA Mode, the USART communication can be managed by 2 DMA Channel requests:
     1. USART_DMAReq_Tx: specifies the Tx buffer DMA transfer request
     2. USART_DMAReq_Rx: specifies the Rx buffer DMA transfer request

  In this Mode it is advised to use the following function:
     - void USART_DMACmd(USART_TypeDef* USARTx, uint16_t USART_DMAReq, FunctionalState NewState);

@endverbatim
  * @{
  */

/**
  * @brief  Enables or disables the specified USART interrupts.
  * @param  USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or 
  *         UART peripheral.
  * @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
  *            @arg USART_IT_LBD:  LIN Break detection interrupt
  *            @arg USART_IT_TXE:  Transmit 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));

  /* The CTS interrupt is not available for UART4 and UART5 */
  if (USART_IT == USART_IT_CTS)
  {
    assert_param(IS_USART_1236_PERIPH(USARTx));
  } 
    
  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  Checks whether the specified USART flag is set or not.
  * @param  USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or 
  *         UART peripheral.
  * @param  USART_FLAG: specifies the flag to check.
  *          This parameter can be one of the following values:
  *            @arg USART_FLAG_CTS:  CTS Change flag (not available for UART4 and UART5)
  *            @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));

  /* The CTS flag is not available for UART4 and UART5 */
  if (USART_FLAG == USART_FLAG_CTS)
  {
    assert_param(IS_USART_1236_PERIPH(USARTx));
  } 
    
  if ((USARTx->SR & USART_FLAG) != (uint16_t)RESET)
  {
    bitstatus = SET;
  }
  else
  {
    bitstatus = RESET;
  }
  return bitstatus;
}

/**
  * @brief  Clears the USARTx's pending flags.
  * @param  USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or 
  *         UART peripheral.
  * @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 (not available for UART4 and UART5).
  *            @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()).
  * @note   RXNE flag can be also cleared by a read to the USART_DR register 
  *          (USART_ReceiveData()).
  * @note   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()).
  * @note   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));

  /* The CTS flag is not available for UART4 and UART5 */
  if ((USART_FLAG & USART_FLAG_CTS) == USART_FLAG_CTS)
  {
    assert_param(IS_USART_1236_PERIPH(USARTx));
  } 
       
  USARTx->SR = (uint16_t)~USART_FLAG;
}

/**
  * @brief  Checks whether the specified USART interrupt has occurred or not.
  * @param  USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or 
  *         UART peripheral.
  * @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 (not available for UART4 and UART5)
  *            @arg USART_IT_LBD:  LIN Break detection interrupt
  *            @arg USART_IT_TXE:  Transmit 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)); 

  /* The CTS interrupt is not available for UART4 and UART5 */ 
  if (USART_IT == USART_IT_CTS)
  {
    assert_param(IS_USART_1236_PERIPH(USARTx));
  } 
    
  /* 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: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or 
  *         UART peripheral.
  * @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 (not available for UART4 and UART5)
  *            @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()).
  * @note   RXNE pending bit can be also cleared by a read to the USART_DR register 
  *          (USART_ReceiveData()).
  * @note   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()).
  * @note   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)); 

  /* The CTS interrupt is not available for UART4 and UART5 */
  if (USART_IT == USART_IT_CTS)
  {
    assert_param(IS_USART_1236_PERIPH(USARTx));
  } 
    
  bitpos = USART_IT >> 0x08;
  itmask = ((uint16_t)0x01 << (uint16_t)bitpos);
  USARTx->SR = (uint16_t)~itmask;
}

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/