4.1.1 Xplained Pro Standard Extension Headers

The SAM4N Xplained Pro headers EXT1, EXT2, and EXT3 offers access to the I/O of the microcontroller in order to expand the board e.g. by connecting extensions to the board. These headers all comply with the Xplained Pro standard extension header. All headers have a pitch of 2.54mm.

Table 4-1. Extension Header EXT1
Pin on EXT1	SAM4N pin	Function	Shared functionality
1	-	-	Communication line to ID chip on extension board
2	-	-	GND
3	PA17	AD0
4	PA18	AD1
5	PA24	GPIO
6	PA25	GPIO	SPARE HEADER2
7	PC23	TIOA3	SPARE HEADER2
8	PC24	TIOB3	SPARE HEADER2
9	PA0	WKUP0
10	PA23	GPIO
11	PA3	TWD0	EXT3
12	PA4	TWCK0	EXT3, SPARE HEADER1
13	PA21	RXD1
14	PA22	TXD1
15	PA11	NPCS0
16	PA13	SPI_MOSI	EXT2, EXT3
17	PA12	SPI_MISO	EXT2, EXT3
18	PA14	SPI_SCK	EXT2, EXT3
19	-	-	GND
20	-	-	VCC

Table 4-2. Extension Header EXT2
Pin on EXT2	SAM4N pin	Function	Shared functionality
1	-	-	Communication line to ID chip on extension board
2	-	-	GND
3	PA19	AD2
4	PA20	AD3
5	PC0	GPIO
6	PC1	GPIO
7	PC26	TIOA4
8	PC27	TIOB4
9	PA1	WKUP1
10	PC8	GPIO
11	PB0	TWD2	EDBG
12	PB1	TWCK2	EDBG
13	PA5	RXD0
14	PA6	TXD0
15	PC4	NPCS1
16	PA13	SPI_MOSI	EXT1, EXT3
17	PA12	SPI_MISO	EXT1, EXT3
18	PA14	SPI_SCK	EXT1, EXT3
19	-	-	GND
20	-	-	VCC

Table 4-3. Extension Header EXT3
Pin on EXT3	SAM4N pin	Function	Shared functionality
1	-	-	Communication line to ID chip on extension board
2	-	-	GND
3	PC29	AD13
4	PC30	AD14
5	PC2	GPIO
6	PC3	GPIO
7	PA26	TIOA2
8	PA27	TIOB2
9	PB2	WKUP12
10	PB3	GPIO
11	PA3	TWD0	EXT1
12	PA4	TWCK0	EXT1, SPARE HEADER1
13	PB10	URXD3
14	PB11	UTXD3
15	PC7	NPCS2
16	PA13	SPI_MOSI	EXT1, EXT2
17	PA12	SPI_MISO	EXT1, EXT2
18	PA14	SPI_SCK	EXT1, EXT2
19	-	-	GND
20	-	-	VCC