When you perform integration testing or topology detection, ARM strongly recommends that the processor is halted, because toggling input and output pins might have an unwanted effect on the operation of the processor. If you follow this recommendation, you must not set the DBGITCTRL Register until the processor has halted.

After you perform integration testing or topology detection, that is, the Integration Mode Control Register has been set, the system must be reset. This is because the signals that are toggled can have an unwanted effect on connected devices.