STM32F103V 4串口电路

interrupts */
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
USART_ITConfig(USART1, USART_IT_TXE, ENABLE);

USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
USART_ITConfig(USART2, USART_IT_TXE, ENABLE);

USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);
USART_ITConfig(USART3, USART_IT_TXE, ENABLE);

USART_ITConfig(UART4, USART_IT_RXNE, ENABLE);
USART_ITConfig(UART4, USART_IT_TXE, ENABLE);
/* Enable the USART1 */
USART_Cmd(USART1, ENABLE);
USART_Cmd(USART2, ENABLE);
USART_Cmd(USART3, ENABLE);
USART_Cmd(UART4, ENABLE);
}

/****************串口1中断************************/
void USART1_IRQHandler(void)
{
unsigned char i;

if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
{

}
USART_ClearITPendingBit(USART1,USART_IT_RXNE); //清中断标识
USART_ITConfig(USART1, USART_IT_TXE, DISABLE);

}