UARTprintf waits indefinitely on TM4C123G Launchpad

I am experimenting with the UARTprintf() function on the TM4C123G Launchpad.

When implementing the UARTprintf function, it is trapped on line 1258 of uart.c (the UARTCharPut function)

while(HWREG(ui32Base + UART_O_FR) & UART_FR_TXFF)

The GPIO pins are configured, and I used the following to configure the UART:

UARTStdioConfig(UART0_BASE, 115200, SysCtlClockGet());

UARTprintf is used in the following line in my main routine:

UARTprintf("Hello\n");

I can use UARTcharPut as a standalone function, and it transmits data no problem into Putty.

Is there something else I am missing in configuring UARTprintf for use?