The UC3-A3 Xplained kit has five 10-pin, 100mil headers. Two headers have a fixed communication interface (J1 and J4). One header has analog functionality (J2), and the last header (J3) has general purpose digital I/O.
The 90° angled header is the JTAG programming and debugging header for the Atmel AT32UC3A3256.
For the location of the respective headers, refer to Figure 1.