After Reset, all outputs are tri-stated, and digital input buffers enabled even if there is no clock running.

The following steps are all optional when initializing PORT operation:

Important: For the lowest possible power consumption, disable the digital input buffer of unused pins and pins are used as analog inputs or outputs. For pins with the digital input buffer enabled it is recommended to transition between the high and low voltage thresholds as quickly as possible.

Specific pins, such as those used to connect a debugger, may be configured differently, as required by their special function.