Three eight-bit General Purpose Input/Output (GPIO) controllers are implemented in the Southbridge. GPIO ports 0 and 1 are available for use as general purpose external I/O on header J33 on the baseboard. GPIO port 3 is used internally by the PB11MPCore. See Figure 3.1 for the location of the GPIO header. The signals are shown in Figure A.6.
Each data pin has an on-board 10KΩ pullup resistor to 3.3V.