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Atmel | SMART SAM R21 [PRELIMINARY DATASHEET SUMMARY]

Atmel-42223AS–SAM-R21_Summary–07/2014

Note:

1.

Die revision A uses GCLK/IO[5].

5.3

Other Functions

5.3.1

Oscillator Pinout

The oscillators are not mapped to the normal PORT functions and their multiplexing are controlled by registers in the

System Controller (SYSCTRL).

The integrated AT86RF233 16 MHz crystal oscillator is directly connected to pins and has no multiplexing functionality.

5.3.2

Serial Wire Debug Interface Pinout

Only the SWCLK pin is mapped to the normal PORT functions. A debugger cold-plugging or hot-plugging detection will

automatically switch the SWDIO port to the SWDIO function.

CLKM

PC16

VDDIO

I/O

GCLK/

IO[1](1)

SCLK

PC18

VDDIO

I/O

SERCOM4/

PAD[3]

MISO

PC19

VDDIO

I/O

SERCOM4/

PAD[0]

Internal

Signal

I/O Pin

Supply

Type

A

B

C

D

E

F

G

H

EIC

REF

ADC

AC

PTC

SERCOM

SERCOM-

ALT

TC

FECTRL

TCC

SERCOM

COM

AC/

GCLK

Oscillator

Supply

Signal

I/O Pin

XOSC

VDDIO

XIN

PA14

XOUT

PA15

XOSC32K

VDDANA

XIN32

PA00

XOUT32

PA01

Oscillator

Supply

Signal

I/O Pin

XOSCRF

EVDD/VDDANA

XTAL1

XTAL1

XTAL2

XTAL2

Signal

Supply

I/O Pin

SWCLK

VDDIO

PA30

SWDIO

VDDIO

PA31