Lesson 08: Troubleshooting

Problem 1: Driver Error

If you get an error message when you download the program code to the target board, or your TI Tiva board does not appear on the debug setting window as shown as the following figures. That means you need to install the driver for the debug interface.

Solution:

1. Download the TI Stellaris ICDI Drive (SW-ICDI-DRIVERS - Current): http://www.ti.com/tool/STELLARIS_ICDI_DRIVERS , and then unzip it into a folder
   
2. Launch your windows Device Manager
3. Looking for "In-Circuit Debug Interface" (there may have 2 or 3 of them)
   
4. Right-click on these devices, and select update driver
   
5. Click "Browse my computer for driver software", and then click Browse... button and navigate to the driver's folder
   
6. It should find and install the correct driver
7. Repeat for all other devices

Problem 2: JTAG functionality has been locked / JTAG Communication Failures

When you attempt to download the program code to the TI Tiva board, a popup window appears with the following error.

"Stellaris ICDI Error: Could not initialize target device! Please power cycle the board and try again."

After you hit accept and another popup window appears with the following error:

"Error: Flash Download failed - Target DLL has been canceled"

Solution:

It is possible to run program code on a Tiva C Series device that causes the device to lose JTAG communication. The two most common causes:

1. Changed the system clock speed to something that the target system does not support.
2. Changed the function of the Port C[3:0], which are muxed with the JTAG pins.

If you accidentally do either of these things, you can restore communication with your target device by running the Debug Port Unlock utility in LM Flash Programmer as shown below.

1. Before using LM Flash Programmer tool, the Stellaris ICDI driver must be installed at your computer. Connect the Tiva LaunchPad to the computer and check the driver at the Device Manager.
2. Download and install LM Flash Programmer onto your computer: http://www.ti.com/tool/lmflashprogrammer
3. Run the LM Flash Programmer
   Make sure that the TI Code Composer Studio and/or Keil μVision are closed, otherwise the IDEs and the LM Flash Programmer will "fight" for control of the board.
   Click LM Flash Programmer icon to launch the Flash Programmer
   

If by using the Debug Port Unlock Utility several times, you are unable to recover your board, then it is possible that there is something damaged at the board. If you don't have the capacity to debug the problem at board level, then I suggest you get a new Tiva LaunchPad.

Problem 3: Keil Real-Board Debugging Issue

If the system is not working as expected, you must use real-board debugging to track the code. Keil supports hardware debugger by selecting hardware debug from Options for Target ➤ Debug as shown in Figure 1.

Figure 1: Selecting Hardware Debug

Next, you have to build the code. If there are no error, then click the debug button  to start the debug and click it again to exit the debug.

When trying to enter hardware debugging mode on Keil μVision, the debugger immediately exits upon entering. Keil can still download object code, but will not run the debugger. Usually, this problem occurs after a while when the Keil debugger is working properly.

The following steps can fix the error:

1. Open windows registry:
   Open Command Prompt window. On the screen type regedit.exe to open Registry Editor. The contents should look similar to the image below:
   
2. In the Registry Editor, search for the directory:
   HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers
   
3. If there is a similar entry to the following items below (the name will depend on the version and the folder you installed Keil), and select the entry
   C:\Keil_v5\UV4\UV4.exe    REG_SZ    $ IgnoreFreeLibrary <lmidk-agdi.dll>
   
   then remove it.
   
4. Reboot the computer and then try again.