I/O Multiplexing

SOIC20 SOIC14 Pin name (1,2) Special ADC0 AC0 DAC0 ZCD3 USARTn SPI0 TWI0(4) TCA0 TCBn TCD0 EVSYS CCL-LUTn
4 4 PA0

XTAL32K1

XTALHF1

EXTCLK

        0,TxD MOSI(3) SDA(H)(3) WO0      

0,IN0

5 5 PA1

XTAL32K2

XTALHF2

        0,RxD MISO(3) SCL(H)(3) WO1      

0,IN1

6   PA2

TWI

Fm+
AIN22      

0,XCK

0,TxD(3)

 

SDA(H)

WO2 0,WO   EVOUTA

0,IN2

7   PA3

TWI

Fm+
AIN23      

0,XDIR

0,RxD(3)

 

SCL(H)

WO3 1,WO     0,OUT
8   PA4   AIN24       0,TxD(3) MOSI   WO4  

WOA

   
9   PA5   AIN25       0,RxD(3) MISO   WO5  

WOB

   
10   PA6   AIN26       0,XCK(3) SCK       WOC   0,OUT(3)
11   PA7 CLKOUT AIN27 OUT   ZCOUT 0,XDIR(3) SS       WOD EVOUTA(3)  
12 6 PC1   AIN29(6)      

1,RxD

0,TxD(3)

SS(3)

MISO(3)

MOSI(3)

  WO1(3)      

1,IN1

13 7 PC2

TWI

Fm+
AIN30(6) AINN3(6)   ZCIN

1,XCK

0,RxD(3)

SCK(3)

MISO(3)

SDA(C)

SDA(H)(3)

WO2(3)     EVOUTC

1,IN2

14 8 PC3

TWI

Fm+
AIN31(6) AINP4(6)    

1,XDIR

0,XCK(3)

SS(3)

SCK(3)

SCL(C)

SCL(H)(3)

WO3(3)       1,OUT
15 9 VDDIO2                          
16 10 PD4   AIN4       0,TxD(3) MOSI(3)   WO4(3)   WOC(3)    
17 11 PD5   AIN5       0,RxD(3) MISO(3)   WO5(3)   WOD(3)    
18 12 PD6   AIN6 AINP3 VOUT  

0,XCK(3)

1,TxD(3)

SCK(3)           2,OUT(3)
19 13 PD7 VREFA AIN7 AINN2    

0,XDIR(3)

1,RxD(3)

SS(3)         EVOUTD(3)  
20 14 VDD                          
1 1 GND                          
2 2 PF6(5) RESET                        
3 3 PF7 UPDI          

SS(3)

        EVOUTF(3)  
Notes:
  1. 1.The pin names are Pxn type, with x being the PORT instance (A, B, C, ...) and n, the pin number. The notation for signals is PORTx_PINn. All pins can be used as event input.
  2. 2.All pins can be used for external interrupt.
  3. 3.Alternate pin positions. Refer to the PORTMUX - Port Multiplexer section for selecting the alternate positions.
  4. 4.The TWI pins that can be used as host or client are marked H. The pins with client-only are marked C.
  5. 5.Input-only.
  6. 6.ADC and AC inputs are available on MVIO pins (PORTC) if the MVIO is disabled in the SYSCFG1.MVSYSCFG fuse setting.