STM32F407的UART4配置

复用PC10, PC11作为串口四的TX, RX

void 
uart4_init(u32 bound)
{
    GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure; 
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC,ENABLE); 
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4,ENABLE); 
	
	GPIO_PinAFConfig(GPIOC,GPIO_PinSource10,GPIO_AF_UART4);
    GPIO_PinAFConfig(GPIOC,GPIO_PinSource11,GPIO_AF_UART4);
	
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; 
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOC, &GPIO_InitStructure);
    
	USART_InitStructure.USART_BaudRate = bound;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
	  
	NVIC_InitStructure.NVIC_IRQChannel = UART4_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority =3;		
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			
	NVIC_Init(&NVIC_InitStructure);
	  
    USART_Init(UART4,&USART_InitStructure);   
    USART_ITConfig(UART4,USART_IT_RXNE,ENABLE);
    USART_Cmd(UART4,ENABLE);
}