Multiplexed Signals

Table 1. PORT Function Multiplexing
VQFN 20-Pin SOIC 20-Pin Pin Name (1,2) Other/Special ADC0 ADC1 PTC(4) AC0 AC1 AC2 DAC0 USART0 SPI0 TWI0 TCA0 TCBn TCD0 CCL
19 16 PA0 RESET/ UPDI AIN0                         LUT0-IN0
20 17 PA1   AIN1             TxD(3) MOSI SDA(3)       LUT0-IN1
1 18 PA2 EVOUT0 AIN2             RxD(3) MISO SCL(3)       LUT0-IN2
2 19 PA3 EXTCLK AIN3             XCK(3) SCK   WO3 TCB1 WO    
3 20 GND      
4 1 VDD      
5 2 PA4   AIN4 AIN0 X0/Y0         XDIR(3) SS   WO4   WOA LUT0-OUT
6 3 PA5 VREFA AIN5 AIN1 X1/Y1 OUT AINN0           WO5 TCB0 WO WOB  
7 4 PA6   AIN6 AIN2 X2/Y2 AINN0 AINP1 AINP0 OUT              
8 5 PA7   AIN7 AIN3 X3/Y3 AINP0 AINP0 AINN0               LUT1-OUT
9 6 PB5 CLKOUT AIN8  

X12/Y12

AINP1   AINP2         WO2(3)      
10 7 PB4   AIN9   X13/Y13 AINN1 AINP3           WO1(3)     LUT0-OUT(3)
11 8 PB3

TOSC1

        OUT     RxD     WO0(3)      
12 9 PB2 TOSC2, EVOUT1           OUT   TxD     WO2      
13 10 PB1   AIN10   X4/Y4 AINP2       XCK   SDA WO1      
14 11 PB0   AIN11   X5/Y5   AINP2 AINP1   XDIR   SCL WO0      
15 12 PC0     AIN6 X6/Y6           SCK(3)     TCB0 WO(3) WOC  
16 13 PC1     AIN7 X7/Y7           MISO(3)       WOD LUT1-OUT(3)
17 14 PC2 EVOUT2   AIN8 X8/Y8           MOSI(3)          
18 15 PC3     AIN9 X9/Y9           SS(3)   WO3(3)     LUT1-IN0
Note:
  1. 1.Pin names are of type Pxn, with x being the PORT instance (A, B) and n the pin number. Notation for signals is PORTx_PINn. All pins can be used as event input.
  2. 2.All pins can be used for external interrupt, where pins Px2 and Px6 of each port have full asynchronous detection.
  3. 3. Alternate pin positions. For selecting the alternate positions, refer to the PORTMUX documentation.
  4. 4.Every PTC line can be configured as X- or Y-line.