请给出stm32f103c8t6用标准库驱动串口3初始化，并实现串口3发送及串口3中断接收

好的，下面是代码实现：

串口3初始化：

#include "stm32f10x.h"

void UART3_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  USART_InitTypeDef USART_InitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;

  /* Enable GPIO clock */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

  /* Enable UART clock */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);

  /* Configure USART Tx and Rx as alternate function push-pull */
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  /* USART configuration */
  USART_InitStructure.USART_BaudRate = 115200;
  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;
  USART_Init(USART3, &USART_InitStructure);

  /* Enable USART3 RX interrupt */
  USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);

  /* Enable USART3 */
  USART_Cmd(USART3, ENABLE);

  /* NVIC configuration */
  NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}

串口3发送：

void UART3_SendByte(uint8_t data)
{
  USART_SendData(USART3, data);
  while(USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET);
}

串口3中断接收：

#include <stdio.h>

void USART3_IRQHandler(void)
{
  if(USART_GetITStatus(USART3, USART_IT_RXNE) != RESET)
  {
    uint8_t data = USART_ReceiveData(USART3);
    printf("Received data: %c\r\n", data);
    USART_ClearITPendingBit(USART3, USART_IT_RXNE);
  }
}

需要注意的是，如果要使用printf函数，需要先初始化UART2，将其作为系统的标准输出端口。