stellaris-M4 GPIOPinConfigure()

Hi, I am trying to communicate UART on the Stellaris cortex-M4 LM4F232. In the example “uart_echo”, it didn’t use the following f(x):

       GPIOPinConfigure(GPIO_PA0_U0RX);

       GPIOPinConfigure(GPIO_PA1_U0TX);

But if I use the pin PE4 and PE5 as U5RX and U5TX，do I must use the  GPIOPinConfigure()?I am pasting my code below:

  When I compile this code by MDK-Keil, there are two errors, my question is:

I have put the “pin_map.h” into my project as Fig.1, and the “pin_map.h” had defined the UART port as Fig.2. Why does it point out the U5RX andU5TX are undefined