This port serves as analog inputs to the Analog-to-digital Converter.
This is an 8-bit, bi-directional I/O port with internal pull-up resistors, individually selectable for each pin. The output buffers have symmetrical drive characteristics, with both high sink and source capability. As inputs, the port pins that are externally pulled low will source current if pull-up resistors are activated. Port pins are tri-stated during a reset condition, even if the clock is not running.