可以用宏定义来实现，得到高效的代码。建议用##连接宏。
/*********************************************************************
* @fn USART_GetITStatus
*
* @brief Checks whether the specified USART interrupt has occurred or not.
*
* @param USARTx - where x can be 1 to select the USART peripheral.
* USART_IT - specifies the USART interrupt source to check.
* USART_IT_LBD - LIN Break detection interrupt.
* USART_IT_TXE - Tansmit Data Register empty interrupt.
* USART_IT_TC - Transmission complete interrupt.
* USART_IT_RXNE - Receive Data register not empty interrupt.
* USART_IT_IDLE - Idle line detection interrupt.
* USART_IT_ORE_RX - OverRun Error interrupt if the RXNEIE bit is set.
* USART_IT_ORE_ER - OverRun Error interrupt if the EIE bit is set.
* USART_IT_NE - Noise Error interrupt.
* USART_IT_FE - Framing Error interrupt.
* USART_IT_PE - Parity Error interrupt.
*
* @return bitstatus: SET or RESET.
*/
ITStatus USART_GetITStatus(USART_TypeDef *USARTx, uint16_t USART_IT)
{
uint32_t bitpos = 0x00, itmask = 0x00, usartreg = 0x00;
ITStatus bitstatus = RESET;
########################################################
usartreg = (((uint8_t)USART_IT) >> 0x05);
itmask = USART_IT & IT_Mask;
itmask = (uint32_t)0x01 << itmask;
if(usartreg == 0x01)
{
itmask &= USARTx->CTLR1;
}
else if(usartreg == 0x02)
{
itmask &= USARTx->CTLR2;
}
else
{
itmask &= USARTx->CTLR3;
}
bitpos = USART_IT >> 0x08;
bitpos = (uint32_t)0x01 << bitpos;
bitpos &= USARTx->STATR;
########################################################
if((itmask != (uint16_t)RESET) && (bitpos != (uint16_t)RESET))
{
bitstatus = SET;
}
else
{
bitstatus = RESET;
}
return bitstatus;
}
