I've been working with this evalboard several month but now I cannot connect any more, neither via ICDI nor via JTAG emulator. LM Flash Programmer told that it cannot find a device. The unlock procedure seemed to be successful, but it was not.
If I try to connect via Blackhawk USB510 JTAG emulator the Code Composer Studio 5.4.0.00091 tells the following error code:
CORTEX_M4_0: Error connecting to the target: (Error -1063 @ 0x0) Device ID is not recognized or is not supported by driver. Confirm device and emulator configuration is correct, or update device driver. (Emulation package 5.0.471.0)
But the whole tool chain is working properly with another LM4F232 evalboard.
In chapter 4.3.2.3 of the Tiva (Stellaris) data sheet I read something about an unlock sequence but I think this was already done by the emulator initialization or LM Flash Programmer's unlock.
After de-asserting Reset the board runs correctly the last programmed image. The frequency of blinking user LED shows that also the clock rate is correct.
Is someone able to tell how could I get into this situation and how can I escape it?