Like Instruction at Address A is Executed and Value on Data Bus Match , the Instruction at Address A is Executed and Value on Data Bus Mismatch trigger type is used in detecting self-modifying code in the memory. For example, one of the instruction in your source code writes a new opcode at its address, ADDR, and you want to trace what executes after the original opcode at ADDR has been replaced. You can set trigger A at ADDR, select the Instruction at Address A is Executed and Value on Data Bus Mismatch option, and specify the original opcode value in the debug configuration. When the application will execute the modified opcode starting with ADDR, a mismatch will occur, and the trigger will be fired.