Question

我正在使用linux uart。在我的应用程序中，我可以通过信号处理程序获取上面的示例代码。

相关链接 - ＆gt; setting serial port interruption in linux

我也使用了上面的代码。链接 - ＆gt; http://www.tldp.org/HOWTO/text/Serial-Programming-HOWTO

  #include <termios.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <sys/signal.h>
  #include <sys/types.h>

  #define BAUDRATE B38400
  #define MODEMDEVICE "/dev/ttyS1"
  #define _POSIX_SOURCE 1 /* POSIX compliant source */
  #define FALSE 0
  #define TRUE 1

  volatile int STOP=FALSE; 

  void signal_handler_IO (int status);   /* definition of signal handler */
  int wait_flag=TRUE;                    /* TRUE while no signal received */

  main()
  {
    int fd,c, res;
    struct termios oldtio,newtio;
    struct sigaction saio;           /* definition of signal action */
    char buf[255];

    /* open the device to be non-blocking (read will return immediatly) */
    fd = open(MODEMDEVICE, O_RDWR | O_NOCTTY | O_NONBLOCK);
    if (fd <0) {perror(MODEMDEVICE); exit(-1); }

    /* install the signal handler before making the device asynchronous */
    saio.sa_handler = signal_handler_IO;
    saio.sa_mask = 0;
    saio.sa_flags = 0;
    saio.sa_restorer = NULL;
    sigaction(SIGIO,&saio,NULL);

    /* allow the process to receive SIGIO */
    fcntl(fd, F_SETOWN, getpid());
    /* Make the file descriptor asynchronous (the manual page says only 
       O_APPEND and O_NONBLOCK, will work with F_SETFL...) */
    fcntl(fd, F_SETFL, FASYNC);

    tcgetattr(fd,&oldtio); /* save current port settings */
    /* set new port settings for canonical input processing */
    newtio.c_cflag = BAUDRATE | CRTSCTS | CS8 | CLOCAL | CREAD;
    newtio.c_iflag = IGNPAR | ICRNL;
    newtio.c_oflag = 0;
    newtio.c_lflag = ICANON;
    newtio.c_cc[VMIN]=1;
    newtio.c_cc[VTIME]=0;
    tcflush(fd, TCIFLUSH);
    tcsetattr(fd,TCSANOW,&newtio);

    /* loop while waiting for input. normally we would do something
       useful here */ 
    while (STOP==FALSE) {
      printf(".\n");usleep(100000);
      /* after receiving SIGIO, wait_flag = FALSE, input is available
         and can be read */
      if (wait_flag==FALSE) { 
        res = read(fd,buf,255);
        buf[res]=0;
        printf(":%s:%d\n", buf, res);
        if (res==1) STOP=TRUE; /* stop loop if only a CR was input */
        wait_flag = TRUE;      /* wait for new input */
      }
    }
    /* restore old port settings */
    tcsetattr(fd,TCSANOW,&oldtio);
  }

  /***************************************************************************
  * signal handler. sets wait_flag to FALSE, to indicate above loop that     *
  * characters have been received.                                           *
  ***************************************************************************/

  void signal_handler_IO (int status)
  {
    printf("received SIGIO signal.\n");
    wait_flag = FALSE;
  }

当某个字节丢失我的uart RX引脚时，此代码会产生中断。但是当我通过write（）函数发送字节时，我想生成另一个中断。

从TX引脚向UART发送字节时如何捕获信号？请问write（）函数生成信号吗？如果是的话我应该抓住哪个信号。？

我应该如何为这个问题做出决定。它会一样吗？

有没有例子或者你有什么建议？

Linux Uart写函数信号处理程序

0 个答案: