Prev: Inter 'Board' Communication
Next: jffs2 corruption on busy local bus.
From: bo on 12 Apr 2010 11:27
I'm having great difficulty getting a 16550 UART to transmit parity/2 stop bits. I'm using vxWorks6.4, Workbench2.6 tools for an MVME5100 (74xx processor board). I get no errors returned on the ioctl() calls and the options read back equal the options set--but the UART is not
transmitting parity bit and not transmitting the 2nd stop bit (in other words, the only change from the default values that works is the change of baudrate to 115.2Kbps.

Any suggestions/comments greatly appreciated. I have opened a TSR with WindRiver on this, but am hoping someone here has encountered this before and know what the problem is.

Thanks, Bo

Here's my initialization code:


void init_uart2(void)
{
int ioctl_return;
int val = 0;
int error_code;
int options = (CS8 | // 8bit data
PARENB | // parity enabled
PARODD | // odd parity
STOPB | // 2 stop bits
CREAD |
CLOCAL);
//unsigned char* uart2_lcr = (unsigned char*) 0xFEF88203; // direct access of LCR via this code
//unsigned char* uart2_scratch = (unsigned char*) 0xFEF88207; // doesn't work either
//volatile unsigned char udata = 0x0;

sio_fd = open("/tyCo/1", O_WRONLY, 0644); // Open serial device
if(sio_fd == ERROR)
{
error_code = errno;
printf("open of serial port returned error\n");
printf("errrno = 0x%08x\n", error_code);
}

ioctl_return = ioctl(sio_fd, FIOBAUDRATE, (int)BAUD_RATE); // Set baud rate
if(ioctl_return == ERROR)
{
error_code = errno;
printf("ioctl(baud rate) returned error\n");
printf("errrno = 0x%08x\n", error_code);
}

ioctl_return = ioctl(sio_fd, FIOSETOPTIONS, OPT_RAW); // Set baud rate
if(ioctl_return == ERROR)
{
error_code = errno;
printf("ioctl(OPT_RAW) returned error\n");
printf("errrno = 0x%08x\n", error_code);
}

ioctl_return = ioctl(sio_fd, FIOSETOPTIONS, options);
if(ioctl_return == ERROR)
{
error_code = errno;
printf("ioctl(options) returned error\n");
printf("errrno = 0x%08x\n", error_code);
}
// ioctl_return = ioctl(sio_fd, SIO_HW_OPTS_GET, val); runs but gives mismatch on write then read option values
ioctl_return = ioctl(sio_fd, FIOGETOPTIONS, val);
if(ioctl_return != options)
{
printf("ioctl(options) don't match desired settings\n");
printf("Desired options = 0x%08X Options read = 0x%08X\n", options, ioctl_return);
}

// *uart2_scratch = (unsigned char) 0xc9; // when this commented out code is run, the read values never
// udata = *uart2_scratch; // equal the written values
//
// *uart2_lcr = (unsigned char) 0x0F;
// udata = *uart2_lcr;

}//end init_uart2()


--------------= Posted using GrabIt =----------------
------= Binary Usenet downloading made easy =---------
-= Get GrabIt for free from http://www.shemes.com/ =-

 | 
Pages: 1
Prev: Inter 'Board' Communication
Next: jffs2 corruption on busy local bus.