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TM4C TivaWare: UART stdio limited to UART0, 1 and 2?

Robert Finger
Genius 17367 points

Hello,

In TivaWare there is support for C stdio output via UART (uartstdio.c). But the implementation only supports UART0, 1 or 2. What is the reason for limiting the supported UARTs? Can UART6 be supported as well, if the source code is changed?

Thanks,
  Robert

  • 0
    Guru 26105 points

    This come from Unix/C/C++ languages - stdio.h defines them for standard streams: stdin, stdout and stderr, (and numbered as 0, 1, 2) which are (automatically an OS) created and opened - but here are mapped by convention to UART0, UART1, UART2 - of coarse if some other UART is mode convenient for pin out for you, you can modify the file (uartstdio.c).

    This file (uartstdio.c) was initially released for Cortex-M3, which had only UART0-2.

    Petrei 

  • 0 in reply to Petrei
    Guru 117855 points

    @Petrei,

    Simply outstanding! 

    The relevant Unix history - past Cortex, tie-in/restriction - and poster's issue, "work-around."

    Know that your past/on-going efforts - very much welcome & appreciated - thanks...

  • 0
    Prodigy 250 points

    "Can UART6 be supported as well, if the source code is changed?"

    Yes.

    The code is fairly simple and shouldn't be difficult to expand.

    On some boards, the UART0's RX/TX pins are hardwired to the ICDI controller's TX/RX pins so if you wish to utilize the virtual com port through the ICDI, you are limited to UART0, unless you hardwire the TX/RX pins.

    This actually opens up the possibility that you can use the board as a serial com device for other purposes.