//源文件

void UartGpioConfig()
{
	RCC->AHB1ENR |= (1<<3);    //使能GPIOD
	RCC->APB1ENR |= (1<<18);   //使能USART3
	RCC->APB2ENR |= 
	
  //PD8  TXD
  GPIOD->MODER |=  (2<<16);  //复用模式
  GPIOD->OSPEEDR |= (2<<16); //High speed
	GPIOD->AFR[1] |= (7<<0);   //AF7
	GPIOD->PUPDR |= (1<<8*2);
	
	//PD9  RXD
  GPIOD->MODER |=  (2<<18);  //复用模式
  GPIOD->OSPEEDR |= (2<<18); //High speed
	GPIOD->AFR[0] |= (7<<4);   //AF7
	GPIOD->PUPDR |= (1<<9*2);
}

void UartCoreConfig(uint32_t bound)
{
   USART3->BRR |= (54*1000000+bound/2)/bound;
	 USART3->CR1 = 0;
	 USART3->CR1 |= 0<<28; //设置 M1=0
   USART3->CR1 |= 0<<12; //设置 M0=0&M1=0,选择 8 位字长
   USART3->CR1 |= 0<<15; //设置 OVER8=0,16 倍过采样
   USART3->CR1 |= 1<<3;  //串口发送使能
	 USART3->CR1 |= 1<<0;    //串口使能
}

void UartPhyConfig()
{
	UartGpioConfig();
	UartCoreConfig(UartBaud);	
}

void UartPhySendByte(uint8_t byte)
{
   USART3->TDR = byte;
	 while((USART3->ISR &(1<<6)) == 0);
}

void UartPhySendString(uint8_t *str)
{
   while(*str)
	 {
	   UartPhySendByte(*str);
		 str++;
	 }
}

//头文件
/*****************************Uart*************************************/
#define  UartBaud   115200

void UartPhyConfig(void);
void UartPhySendByte(uint8_t byte);
void UartPhySendString(uint8_t *str);
/**********************************************************************/