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Altera_Forum's avatar
Altera_Forum
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20 years ago

uart with cts/rts

Hello,

I am using an uart with CTS/RTS, and I am experiencing serial communications problems. When I am trying to communicate at 115200 bauds, I often get "input overrun(s)". It seems that means the driver is not quick enough to catch and process all characters. I cannot see any difference whether I use CTS/RTS or not... Is it implemented, and does the driver take care of it ? When trying 'stty -D /dev/ttyS1 115200 crtscts', I get a message saying that not all operations were performed, and only the baudrate change is made.

Anyway, with or without the CTS/RTS function, does someone have an idea of how to improve the uart performance ?

Thanks

Regards

Pod

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    I don't think the Linux NiosSerial driver (for the altera_avalon_uart) supports RTS/CTS... and I don't believe that the JTAG UART driver supports it either.

    In fact, depending on which development board you're using, you may not be able to get RTS/CTS support at all since some of the DB9 pins may be re-mapped or not connected at all.

    As for how to improve the the performance of the UART... without the extra signals, you've gotta pull the data out of the buffer faster. So... faster design? Less stuff going on in the background? higher priority interrupt?

    hope this helps.