正在用I.MX283，UART编程有些问题

只看该作者 · 2015-5-16 12:21

1.我使用I.MX UART0,1编程，程序如下：
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <limits.h>
#include <asm/ioctls.h>
#include <time.h>
#include <pthread.h>

#define DATA_LEN             0xFF                                  /* test data's len             */

//#define DEBUG                1

/*********************************************************************************************************
** Function name:          openSerial
** Descriptions:          open serial port at raw mod
** input paramters:       iNum       serial port which can be value at: 1, 2, 3, 4
** output paramters:       NONE
** Return value:          file descriptor
** Create by:             zhuguojun
** Create Data:          2008-05-19
**--------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
**--------------------------------------------------------------------------------------------------------
*********************************************************************************************************/
static int openSerial(char *cSerialName)
{
int iFd;

struct termios opt;

iFd = open(cSerialName, O_RDWR | O_NOCTTY);
if(iFd < 0) {
      perror(cSerialName);
      return -1;
}

tcgetattr(iFd, &opt);

//cfsetispeed(&opt, B57600);
//cfsetospeed(&opt, B57600);

   cfsetispeed(&opt, B2400);
   cfsetospeed(&opt, B2400);

/*
   * raw mode
   */
opt.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
opt.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
opt.c_oflag &= ~(OPOST);
opt.c_cflag &= ~(CSIZE | PARENB);
opt.c_cflag |= PARENB;
opt.c_cflag &= ~PARODD;
opt.c_cflag |= CS8;
opt.c_iflag |= (INPCK | ISTRIP);
/*
   * 'DATA_LEN' bytes can be read by serial
   */
opt.c_cc[VMIN] = DATA_LEN;
opt.c_cc[VTIME]  = 150;

if (tcsetattr(iFd, TCSANOW, &opt)<0) {
      return -1;
}

return iFd;
}

int main(void)
{
char tmp[1024];
int len;
int fd, i;
char sendbuf[]={0xFE,0xFE,0xFE,0x68,0x46,0x53,0x00,0x13,0x27,0x00,0x00,0x00,0x01,0x03,0x90,0x1F};
int lenbuf = sizeof(sendbuf);
fd = openSerial("/dev/ttySP4");
printf("serial test111!\n");
for(i = 0; i < 16; i++)
tmp[i] = i%0xFF;

//write(fd, tmp, 16);
write(fd,sendbuf,lenbuf);
while (1) {
len = read(fd, tmp, 0x01);
for(i = 0; i < len; i++)
printf(" %x", tmp[i]);
printf("\n");
}
}
然后外部RX和TX短接，发现上来的数据高位都变成了0，也就是接收本来正确的应该是0xfE，现在变成了0x7e，有时候还会出现
mxs-auart mxs-auart.1: Unhandled status 500400，
请问是啥问题