Xplained Pro Standard Extension Headers

The XMEGA A1U Xplained Pro headers EXT1, EXT2, and EXT3 offer 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 standard extension header specified in Xplained Pro Standard Extension Header. All headers have a pitch of 2.54mm.

Table 1. Extension Header EXT1
Pin on EXT1 XMEGA pin Function Shared functionality
1 [ID] - - Communication line to ID chip on extension board
2 [GND] - - GND
3 [ADC(+)] PA0 ADCA0 (GAINPOS) Alternate signal header
4 [ADC(-)] PA4 ADCA4 (GAINNEG)  
5 [GPIO1] PE6 GPIO  
6 [GPIO2] PE7 GPIO Alternate signal header
7 [PWM(+)] PE1 TCC0 OC0B  
8 [PWM(-)] PE0 TCC0 OC0A  
9 [IRQ/GPIO] PR0 GPIO  
10 [SPI_SS_B/GPIO] PR1 GPIO  
11 [TWI_SDA] PC0 TWIC SDA EDBG and LCD Connector
12 [TWI_SCL] PC1 TWIC SCL EDBG and LCD Connector
13 [USART_RX] PC2 USARTC0 RXD0  
14 [USART_TX] PC3 USARTC0 TXD0  
15 [SPI_SS_A] PC4 SPIC SS  
16 [SPI_MOSI] PC5 SPIC MOSI EXT2, EXT3, and LCD Connector
17 [SPI_MISO] PC6 SPIC MISO EXT2, EXT3, LCD Connector, and Alternate signal header
18 [SPI_SCK] PC7 SPIC SCK EXT2, EXT3, LCD Connector, and Alternate signal header
19 [GND] - - GND
20 [VCC] - - VCC
Table 2. Extension Header EXT2
Pin on EXT2 XMEGA pin Function Shared functionality
1 [ID] - - Communication line to ID chip on extension board
2 [GND] - - GND
3 [ADC(+)] PA1 ADCA1 (GAINPOS)  
4 [ADC(-)] PA6 ADCA6 (GAINNEG) Alternate signal header
5 [GPIO1] PB4 GPIO  
6 [GPIO2] PB5 GPIO  
7 [PWM(+)] PE5 TCE1 OC1B  
8 [PWM(-)] PE4 TCE1 OC1A  
9 [IRQ/GPIO] PB6 GPIO Alternate signal header
10 [SPI_SS_B/GPIO] PB7 GPIO Alternate signal header
11 [TWI_SDA] PF0 TWIF SDA EXT3
12 [TWI_SCL] PF1 TWIF SCL EXT3
13 [USART_RX] PF2 USARTF0 RXD0  
14 [USART_TX] PF3 USARTF0 TXD0  
15 [SPI_SS_A] PF4 GPIO  
16 [SPI_MOSI] PC5 SPIC MOSI EXT1, EXT3, and LCD Connector
17 [SPI_MISO] PC6 SPIC MISO EXT1, EXT3, LCD Connector, and Alternate signal header
18 [SPI_SCK] PC7 SPIC SCK EXT1, EXT3, LCD Connector, and Alternate signal header
19 [GND] - - GND
20 [VCC] - - VCC
Table 3. Extension Header EXT3
Pin on EXT3 XMEGA pin Function Shared functionality
1 [ID] - - Communication line to ID chip on extension board
2 [GND] - - GND
3 [ADC(+)] PA3 ADCA3 (GAINPOS)  
4 [ADC(-)] PA7 ADCA7 (GAINNEG) Alternate signal header
5 [GPIO1] PK0 GPIO  
6 [GPIO2] PK1 GPIO  
7 [PWM(+)] PD5 TCD1 OC1B  
8 [PWM(-)] PD4 TCD1 OC1A  
9 [IRQ/GPIO] PK2 GPIO  
10 [SPI_SS_B/GPIO] PK3 GPIO  
11 [TWI_SDA] PF0 TWIF SDA EXT2
12 [TWI_SCL] PF1 TWIF SCL EXT2
13 [USART_RX] PF6 USARTF1 RXD1  
14 [USART_TX] PF7 USARTF1 TXD1  
15 [SPI_SS_A] PD0 GPIO  
16 [SPI_MOSI] PC5 SPIC MOSI EXT1, EXT2, and LCD Connector
17 [SPI_MISO] PC6 SPIC MISO EXT1, EXT2, LCD Connector, and Alternate signal header
18 [SPI_SCK] PC7 SPIC SCK EXT1, EXT2, LCD Connector, and Alternate signal header
19 [GND] - - GND
20 [VCC] - - VCC