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Altera_Forum
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20 years ago

NIOS Uart : change baud rate

I am having trouble to change the baud rate of a NIOS avalon uart. Note that I am not running against any OS, just the "standard" native NIOS environment. I tried : alt_avalon_uart_ioc...
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Altera_Forum
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20 years ago

Thanks very much for the precise response.

It works. I wasn't aware of the ALTERA_AVALON_UART_USE_IOCTL.

Cheers,

-- Richard --

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originally posted by vlorenzo@Jan 14 2006, 11:05 AM

for being able of modifying the uart baudrate, check theese:

- in sopcbuilder open the editor dialog for the uart component in your system (double click on it), there is a parametter for including an uart bauderate register;

- make sure that you're not using the reduced footprint driver's hal mode in your system library;

- include this define altera_avalon_uart_use_ioctl in the compiler preprocessor configuration settings for your system library and recompile it;

- add the includes# include <sys/ioctl.h> and# include <sys/termios.h> to your source file;

now you can use code like this for changing the uart speed:

struct termios termios;

int res = ioctl( uartfd, tiocmget, &termios );

termios.c_ispeed = your_new_bauderate;

termios.c_ospeed = your_new_bauderate;

res = ioctl( uartfd, tiocmset, &termios );

the above code can be used provided that you opened the uart using code like:

int uartfd;

uartfd = open( your_uart_device_name, o_rdwr | o_nonblock | o_noctty );

if (uartfd == -1)

{

printf( "fatal error with uart \"%s\"\r\n", uart_name );

return 1;

}

the options are ored according to my needs, which could be a little bit different from yours.

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