5.

I/O Multiplexing and Considerations

5.1

Multiplexed Signals

Table 5-1. PORT Function Multiplexing

Pin Name (1,2)

Other/Special

ADC0

PTC(3)

AC0

DAC0

USART0

SPI0

TWI0

TCA0

TCB0

TCD0

CCL

23 PA0

RESET

UPDI

AIN0

LUT0-IN0

24 PA1

BREAK

AIN1

TXD

MOSI

SDA

LUT0-IN1

1

PA2

EVOUT0

AIN2

RxD

MISO

SCL

LUT0-IN2

2

PA3

EXTCLK

AIN3

XCK

SCK

WO3

3

GND

4

VDD

5

PA4

AIN4

X0/Y0

XDIR

SS

WO4

WOA

LUT0-OUT

6

PA5

AIN5

X1/Y1

OUT

WO5

WO

WOB

7

PA6

AIN6

X2/Y2

AINN0

OUT

8

PA7

AIN7

X3/Y3

AINP0

LUT1-OUT

9

PB7

10 PB6

11

PB5

CLKOUT

AIN8

AINP1

WO2

12 PB4

AIN9

AINN1

WO1

LUT0-OUT

13 PB3

TOSC1

RxD

WO0

14 PB2

TOSC2, EVOUT1

TxD

WO2

15 PB1

AIN10

X4/Y4

XCK

SDA

WO1

16 PB0

AIN11

X5/Y5

XDIR

SCL

WO0

17 PC0

SCK

WO

WOC

18 PC1

MISO

WOD

LUT1-OUT

19 PC2

EVOUT2

MOSI

20 PC3

SS

WO3

LUT1-IN0

21 PC4

BREAK

WO4

LUT1-IN1

22 PC5

WO5

LUT1-IN2

Note: 

1.

Pins 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.

All pins can be used for external interrupt, where pins Px2 and Px6 of each port have full

asynchronous detection.

3.

PTC is only available in devices with 8KB Flash (ATtiny817). Every PTC line can be configured as

X-line or Y-line.

Tip:  Signals on alternative pin locations are in typewriter font.

ATtiny417/817

© 2017 Microchip Technology Inc.

Datasheet Summary

DS40001934A-page 10