Question about configuring UART7

Hello,

I have acquired recently a Tiva-C TM4C1294XL board, installed CCS 6, installed all drivers and now the board is connected to my PC and working properly. I ran some demos successfully.

I ran also the uart_echo demo and, after understand the way it works, I did some changes trying to configure the UART5 (PC4 and PC5 pins) to work. In fact, I would like to write in UART7 and receive the data in UART0. After that the UART0 would write to itself and the character would appear on hyperterminal.

I connected the pins PC4 (U7RX) to PA1(U0TX) and PC5(U7TX) to PA0(U0RX) but I have no success on this task. Please see below the source code I am using. Any advice? 

Tks.

//*****************************************************************************
//
// uart_echo.c - Example for reading data from and writing data to the UART in
// an interrupt driven fashion.
//
// Copyright (c) 2013-2014 Texas Instruments Incorporated. All rights reserved.
// Software License Agreement
//
// Texas Instruments (TI) is supplying this software for use solely and
// exclusively on TI's microcontroller products. The software is owned by
// TI and/or its suppliers, and is protected under applicable copyright
// laws. You may not combine this software with "viral" open-source
// software in order to form a larger program.
//
// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
// DAMAGES, FOR ANY REASON WHATSOEVER.
//
// This is part of revision 2.1.0.12573 of the EK-TM4C1294XL Firmware Package.
//
//*****************************************************************************

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "driverlib/debug.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"

//*****************************************************************************
//
//! \addtogroup example_list
//! <h1>UART Echo (uart_echo)</h1>
//!
//! This example application utilizes the UART to echo text. The first UART
//! (connected to the USB debug virtual serial port on the evaluation board)
//! will be configured in 115,200 baud, 8-n-1 mode. All characters received on
//! the UART are transmitted back to the UART.
//
//*****************************************************************************

//****************************************************************************
//
// System clock rate in Hz.
//
//****************************************************************************
uint32_t g_ui32SysClock;

//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif

//*****************************************************************************
//
// The UART interrupt handler.
//
//*****************************************************************************
void
UARTIntHandler(void)
{
uint32_t ui32Status;
uint32_t theChar;

//
// Get the interrrupt status.
//
ui32Status = ROM_UARTIntStatus(UART0_BASE, true);
// ui32Status = ROM_UARTIntStatus(UART7_BASE, true);

//
// Clear the asserted interrupts.
//
ROM_UARTIntClear(UART0_BASE, ui32Status);
// ROM_UARTIntClear(UART7_BASE, ui32Status);

//
// Loop while there are characters in the receive FIFO.
//
while(ROM_UARTCharsAvail(UART0_BASE))
// while(ROM_UARTCharsAvail(UART7_BASE))
{
//
// Read the next character from the UART and write it back to the UART.
//
// ROM_UARTCharPutNonBlocking(UART0_BASE,
// ROM_UARTCharGetNonBlocking(UART0_BASE));

theChar = ROM_UARTCharGetNonBlocking(UART0_BASE);
//theChar = ROM_UARTCharGetNonBlocking(UART7_BASE);

ROM_UARTCharPut(UART0_BASE, theChar);

//
// Blink the LED to show a character transfer is occuring.
//
GPIOPinWrite(GPIO_PORTN_BASE, GPIO_PIN_0, GPIO_PIN_0);

//
// Delay for 1 millisecond. Each SysCtlDelay is about 3 clocks.
//
SysCtlDelay(g_ui32SysClock / 100);

//
// Turn off the LED
//
GPIOPinWrite(GPIO_PORTN_BASE, GPIO_PIN_0, 0);

//
// Delay for 1 millisecond. Each SysCtlDelay is about 3 clocks.
//
SysCtlDelay(g_ui32SysClock / 100);
}
}

//*****************************************************************************
//
// Send a string to the UART.
//
//*****************************************************************************
void
UARTSend(const uint8_t *pui8Buffer, uint32_t ui32Count)
{
//
// Loop while there are more characters to send.
//
while(ui32Count--)
{
//
// Write the next character to the UART.
//
// ROM_UARTCharPutNonBlocking(UART0_BASE, *pui8Buffer++);
ROM_UARTCharPutNonBlocking(UART7_BASE, *pui8Buffer++);
}
}

//*****************************************************************************
//
// This example demonstrates how to send a string of data to the UART.
//
//*****************************************************************************
int
main(void)
{
int i;
//
// Set the clocking to run directly from the crystal at 120MHz.
//
g_ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
SYSCTL_OSC_MAIN |
SYSCTL_USE_PLL |
SYSCTL_CFG_VCO_480), 120000000);
//
// Enable the GPIO port that is used for the on-board LED.
//
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);

//
// Enable the GPIO pins for the LED (PN0).
//
ROM_GPIOPinTypeGPIOOutput(GPIO_PORTN_BASE, GPIO_PIN_0);
ROM_GPIOPinTypeGPIOOutput(GPIO_PORTN_BASE, GPIO_PIN_1);

//
// Enable the peripherals used by this example.
//
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART7);
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC); // Habilita os pinos do conjunto C

//
// Enable processor interrupts.
//
ROM_IntMasterEnable();

//
// Set GPIO A0 and A1 as UART pins.
//
GPIOPinConfigure(GPIO_PA0_U0RX);
GPIOPinConfigure(GPIO_PA1_U0TX);
GPIOPinConfigure(GPIO_PC4_U7RX);
GPIOPinConfigure(GPIO_PC5_U7TX);
ROM_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);
ROM_GPIOPinTypeUART(GPIO_PORTC_BASE, GPIO_PIN_4 | GPIO_PIN_5);

//
// Configure the UART for 115,200, 8-N-1 operation.
//
ROM_UARTConfigSetExpClk(UART0_BASE, g_ui32SysClock, 115200,
(UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
UART_CONFIG_PAR_NONE));
ROM_UARTConfigSetExpClk(UART7_BASE, g_ui32SysClock, 115200,
(UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
UART_CONFIG_PAR_NONE));

//
// Enable the UART interrupt.
//
ROM_IntEnable(INT_UART0);
ROM_UARTIntEnable(UART0_BASE, UART_INT_RX | UART_INT_RT);
// ROM_IntEnable(INT_UART7);
// ROM_UARTIntEnable(UART7_BASE, UART_INT_RX | UART_INT_RT);

//
// Prompt for text to be entered.
//
UARTSend((uint8_t *)"AT\r\n", 4);
// Loop forever echoing data through the UART.

//
while(1)
{
UARTSend((uint8_t *)"AT\r\n", 4);}

}