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求助:USART的中断问题

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发表于 2012-10-8 09:04:24 | 显示全部楼层 |阅读模式
关于usart的通信,一直是似懂非懂的阶段。
   我想问的是在一个main()中,并没有用到如 USART_SendBit()等函数,而是使能串口后,用
while (1)
  {
  while(RxCounter1<RxBufferSize1)
  {}
表示串口2的数据发送给了串口1,这里一直不懂,为什么就实现了数据的收发。
  是DMA?  但是这程序中也并没有初始化DMA控制。
真心求解 希望解答,谢谢了。
  
附源码:
#include "stm32f10x.h"
#include "platform_config.h"
#include "stm32_eval.h"
#include <stdio.h>
/** @addtogroup STM32F10x_StdPeriph_Examples
  * @{
  */
/** @addtogroup USART_Interrupt
  * @{
  */
GPIO_InitTypeDef GPIO_InitStructure;
/* Private typedef -----------------------------------------------------------*/
typedef enum { FAILED = 0, PASSED = !FAILED} TestStatus;
/* Private define ------------------------------------------------------------*/
#define TxBufferSize1   (countof(TxBuffer1) - 1)
#define TxBufferSize2   (countof(TxBuffer2) - 1)
#define RxBufferSize1   TxBufferSize2
#define RxBufferSize2   TxBufferSize1
/* Private macro -------------------------------------------------------------*/
#define countof(a)   (sizeof(a) / sizeof(*(a)))
/* Private variables ---------------------------------------------------------*/
USART_InitTypeDef USART_InitStructure;
uint8_t TxBuffer1[] = "串口中断收发示例: 串口1 -> PC (中断收发)";
uint8_t TxBuffer2[] = "Y";
uint8_t RxBuffer1[RxBufferSize1];
uint8_t RxBuffer2[RxBufferSize2];
__IO uint8_t TxCounter1 = 0x00;
__IO uint8_t RxCounter1 = 0x00;
uint8_t NbrOfDataToTransfer1 = TxBufferSize1;
uint8_t NbrOfDataToRead1 = RxBufferSize1;
__IO TestStatus TransferStatus1 = FAILED;
/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);
void NVIC_Configuration(void);
TestStatus Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength);
#ifdef __GNUC__
  /* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf
     set to 'Yes') calls __io_putchar() */
  #define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
  #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
/* Private functions ---------------------------------------------------------*/
/**
  * @brief   Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /*!< At this stage the microcontroller clock setting is already configured,
       this is done through SystemInit() function which is called from startup
       file (startup_stm32f10x_xx.s) before to branch to application main.
       To reconfigure the default setting of SystemInit() function, refer to
       system_stm32f10x.c file
     */     
      
  /* System Clocks Configuration */
  RCC_Configuration();
      
  /* NVIC configuration */
  NVIC_Configuration();
  
  /* Configure the GPIO ports */
  GPIO_Configuration();
  
  GPIO_SetBits(GPIO_LED,DS1_PIN|DS2_PIN|DS3_PIN|DS4_PIN);/*关闭所有的LED指示灯*/
/* USART1 and USART2 configuration ------------------------------------------------------*/
  /* USART1 and USART2 configured as follow:
        - BaudRate = 9600 baud  
        - Word Length = 8 Bits
        - One Stop Bit
        - No parity
        - Hardware flow control disabled (RTS and CTS signals)
        - Receive and transmit enabled
  */
  USART_InitStructure.USART_BaudRate = 115200;               /*设置波特率为115200*/
  USART_InitStructure.USART_WordLength = USART_WordLength_8b;/*设置数据位为8*/
  USART_InitStructure.USART_StopBits = USART_StopBits_1;     /*设置停止位为1位*/
  USART_InitStructure.USART_Parity = USART_Parity_No;        /*无奇偶校验*/
  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;/*无硬件流控*/
  USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;  /*发送和接收*/
  /*配置串口1 */
  USART_Init(USART1, &USART_InitStructure);
  /*配置串口2*/
// USART_Init(USART2, &USART_InitStructure);
  
  /*使能串口1的发送和接收中断*/
  USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
//  USART_ITConfig(USART1, USART_IT_TXE, ENABLE);
  /*使能串口2的发送和接收中断*/
//  USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
//  USART_ITConfig(USART2, USART_IT_TXE, ENABLE);
  /* 使能串口1 */
  USART_Cmd(USART1, ENABLE);
  /* 使能串口2 */
//  USART_Cmd(USART2, ENABLE);
  /* Wait until end of transmission from USART1 to USART2 */
  printf(" Hello World!\n");
  /* Wait until end of transmission from USART2 to USART1 */
//  while(RxCounter1 < RxBufferSize1)
//   {
//   }
  
  /* Check the received data with the send ones */
//  TransferStatus1 = Buffercmp(TxBuffer1, RxBuffer1, RxBufferSize1);
  /* TransferStatus1 = PASSED, if the data transmitted from USART2 and  
     received by USART1 are the same */
  /* TransferStatus1 = FAILED, if the data transmitted from USART2 and
     received by USART1 are different */
  
  /* TransferStatus2 = PASSED, if the data transmitted from USART1 and  
     received by USART2 are the same */
  /* TransferStatus2 = FAILED, if the data transmitted from USART1 and
     received by USART2 are different */

  while (1)
  {
  while(RxCounter1<RxBufferSize1)
  {}
   RxCounter1=0;
TransferStatus1  = Buffercmp(TxBuffer2, RxBuffer1, RxBufferSize1);
       if(TransferStatus1 == PASSED)
       {
           GPIO_ResetBits(GPIO_LED,DS1_PIN);/*点亮DS1,串口1接收的数据与串口2发送的数据相同*/
       }
       else if(TransferStatus1 == FAILED)
       {
           GPIO_ResetBits(GPIO_LED,DS2_PIN);/*点亮DS2,串口1接收的数据与串口2发送的数据不相同*/
       }
      
  }
}
/**
  * @brief  Configures the different system clocks.
  * @param  None
  * @retval None
  */
void RCC_Configuration(void)
{   
  /*使能串口1和串口2使用的GPIO时钟*/
  RCC_APB2PeriphClockCmd(USART1_GPIO_CLK |USART2_GPIO_CLK, ENABLE);
  /* Enable USART1 Clock */
  /*使能串口1时钟*/
  RCC_APB2PeriphClockCmd(USART1_CLK, ENABLE);
  /*使能串口2时钟*/
  RCC_APB1PeriphClockCmd(USART2_CLK, ENABLE);  
  /*使能LED灯使用的GPIO时钟*/
  RCC_APB2PeriphClockCmd(RCC_GPIO_LED, ENABLE);
}
/**
  * @brief  Configures the different GPIO ports.
  * @param  None
  * @retval None
  */
void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  /*串口1 RX管脚配置*/
  /* Configure USART1 Rx as input floating */
  GPIO_InitStructure.GPIO_Pin = USART1_RxPin;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(USART1_GPIO, &GPIO_InitStructure);
  /*串口2 RX管脚配置*/
  /* Configure USART2 Rx as input floating */
  GPIO_InitStructure.GPIO_Pin = USART2_RxPin;
  GPIO_Init(USART2_GPIO, &GPIO_InitStructure);  
  /*串口1 TX管脚配置*/
  /* Configure USART1 Tx as alternate function push-pull */
  GPIO_InitStructure.GPIO_Pin = USART1_TxPin;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(USART1_GPIO, &GPIO_InitStructure);
  /*串口2 TX管脚配置*/
  /* Configure USART2 Tx as alternate function push-pull */
  GPIO_InitStructure.GPIO_Pin = USART2_TxPin;
  GPIO_Init(USART2_GPIO, &GPIO_InitStructure);  
  /* 配置神舟III号LED灯使用的GPIO管脚模式*/
  GPIO_InitStructure.GPIO_Pin = DS1_PIN|DS2_PIN|DS3_PIN|DS4_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIO_LED, &GPIO_InitStructure);
}
/**
  * @brief  Configures the nested vectored interrupt controller.
  * @param  None
  * @retval None
  */
void NVIC_Configuration(void)
{
  NVIC_InitTypeDef NVIC_InitStructure;
  /* Configure the NVIC Preemption Priority Bits */  
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
  
  /* Enable the USART1 Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
  /* Enable the USART2 Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}

/**
  * @brief  Compares two buffers.
  * @param  pBuffer1, pBuffer2: buffers to be compared.
  * @param  BufferLength: buffer's length
  * @retval PASSED: pBuffer1 identical to pBuffer2
  *   FAILED: pBuffer1 differs from pBuffer2
  */
TestStatus Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength)
{
  while(BufferLength--)
  {
    if(*pBuffer1 != *pBuffer2)
    {
      return FAILED;
    }
    pBuffer1++;
    pBuffer2++;
  }
  return PASSED;
}

/**
  * @brief  Retargets the C library printf function to the USART.
  * @param  None
  * @retval None
  */
PUTCHAR_PROTOTYPE
{
  /* Place your implementation of fputc here */
  /* e.g. write a character to the USART */
  USART_SendData(EVAL_COM1, (uint8_t) ch); /*发送一个字符函数*/
  /* Loop until the end of transmission */
  while (USART_GetFlagStatus(EVAL_COM1, USART_FLAG_TC) == RESET)/*等待发送完成*/
  {
  
  }
  return ch;
}
#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t* file, uint32_t line)
{
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* Infinite loop */
  while (1)
  {
  }
}
#endif
/**
  * @}
  */
/**
  * @}
  */
/******************* (C) COPYRIGHT 2010 STMicroelectronics *****END OF FILE****/

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发表于 2012-10-8 10:45:29 | 显示全部楼层
数据发送处理应该是在串口中断程序里面吧
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 楼主| 发表于 2012-10-8 15:46:54 | 显示全部楼层
wdluo 发表于 2012-10-8 10:45
数据发送处理应该是在串口中断程序里面吧

可是这个程序里面只有 nvic和rcc来初始化和使能串口啊。并没有说的串口中断、
难道是使能后就能自动检测数据并且收发?
  或者在头文件中还包含了另外的程序只是我没看到?  唉,一直被困扰啊。
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 楼主| 发表于 2012-10-8 16:01:58 | 显示全部楼层
wdluo 发表于 2012-10-8 10:45
数据发送处理应该是在串口中断程序里面吧

呵呵  谢谢,折腾了这么久。 果然是还有个void USART1_IRQHandler(void)没看到。
唉,太粗心大意了。  非常感谢
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发表于 2012-10-13 21:59:27 | 显示全部楼层
呵呵,不小心造成的
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发表于 2012-10-24 17:17:06 | 显示全部楼层
支持楼主
不了解中断的话,可以多做几个简单的中断看看
比如tim,systick。。
这些中断不需要硬件配置,对理解中断挺好的
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