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Cannot Configure UART0 in TM4C1294NCPDT

Mary Ann
Intellectual 440 points

Please check the following code for configuring uart0 in TM4C1294NCPDT. Its sending data out.

main()
{
SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480), 120000000);
UART_INIT();
}

void UART_INIT (void) 
{
SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

UARTDisable(UART0_BASE);
UARTFIFODisable(UART0_BASE);
UARTConfigSetExpClk(UART0_BASE, SysCtlClockGet(), 115200,(UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |UART_CONFIG_PAR_NONE));

GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0); // U0RX
GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_1); //U0TX

GPIOPinConfigure(GPIO_PA1_U0TX);
GPIOPinConfigure(GPIO_PA0_U0RX);
UARTFlowControlSet(UART0_BASE, UART_FLOWCONTROL_NONE);

UARTFIFOEnable(UART0_BASE);
UARTEnable(UART0_BASE);

UARTCharPut(UART0_BASE, 'A');
UARTCharPut(UART0_BASE, 'T');

}

Please do respond asap...


Thanks
Mary Ann

  • 0
    Intellectual 440 points
    Sorry ITs not transmitting / receiving
  • 0
    Guru 26105 points

    Hi,

    Please see in your Tiva/ examples/boards/your_board/uart_echo project - just import it in your tool chain to have a good configuration.

    Also, your main function could be good for DOS programs, but not for embedded world - here you do not have an operating system to allow you to get out of main, so your micro must spin only in main. Something like this:

    main()
    {
    SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480), 120000000);
    UART_INIT();

    while(1){;}

    }

    Also, useful to read the user manual - see the UART FIFO - how deep is, compare with your configuration. If you need to send only two characters, maybe will be a good idea to disable the FIFO, but after enabling the UART, since this function implicitly enables the FIFO.

  • 0
    Intellectual 750 points
    Mary Ann,

    SysCtlClockGet() does not work on TM4C129 devices.
    See this thread:
    http://e2e.ti.com/support/microcontrollers/tiva_arm/f/908/t/324693

    Randy