STK1000/GPIO headers
From AVRFreaks Wiki
Input/Output (IO) lines on AVR32 are commonly used to drive LED's and read input from switches.
The GPIO header holds a collection of 32 General Purpose Input Output (GPIO) signals that allow you to work with input/output lines from the processor on the daughter board.
The most common use of these signals are to connect IO lines to the switches and LED's on STK1000. The GPIO lines can also be used to connect custom peripherals.
The General Purpose Input Output header (GPIO header) allows for an easy to use connection of 32 GPIO signals from the processor on the mounted daughter board. The GPIO signals routed to these headers depend on the implementation selected for each daughter board. Note that it is not common that the 32 GPIO signals represent a port on the processor.
Pin out
Note that GPIO[27..31] are connected to signals on the CF connector and the MMC/SD connector.
The GPIO header is located to the left of the LCD screen just above the headers for connecting user LEDs and user switches.
Interfaces
Refer the help files of the daughter board to find out what interfaces are used and which peripheral on the processor are connected to the interface.