5 Signal Descriptions List

The following table provides details on signal names classified by peripherals.

Table 5-1. Signal Descriptions List
Signal Name	Function	Type
Generic Clock Generator - GCLK
GCLK_IO[4:0]	Generators Clock Source (Input) or Generic Clock Signal (Output)	Digital I/O
Oscillators Control - OSCCTRL
XIN	Crystal Oscillator or External Clock Input	Analog Input (Crystal Oscillator)/Digital Input (External Clock)
XOUT	Crystal Oscillator Output	Analog Output
32 kHz Oscillators Control - OSC32KCTRL
XIN32	32.768 kHz Crystal Oscillator or External Clock Input	Analog Input (Crystal Oscillator)/Digital Input (External Clock)
XOUT32	32.768 kHz Crystal Oscillator Output	Analog Output
Serial Communication Interface - SERCOMx
PAD[3:0]	General SERCOM Pins	Digital I/O
Timer Counter - TCx
WO[1:0]	Capture Inputs or Waveform Outputs	Digital I/O
Real Timer Clock - RTC
IN[3:0]	Tamper Detection Inputs	Digital Input
OUT[3:0]	Tamper Detection Outputs	Digital Output
Analog Comparators - AC
AIN[3:0]	AC Comparator Inputs	Analog Input
CMP[1:0]	AC Comparator Outputs	Digital Output
Analog Digital Converter - ADC
AIN[9:0]	ADC Input Channels	Analog Input
VREFA⁽¹⁾	ADC External Reference Voltage A	Analog Input
VREFB	ADC External Reference Voltage B	Analog Input
Digital Analog Converter - DAC
VOUT	DAC Voltage Output	Analog Output
VREFA⁽¹⁾	DAC External Reference Voltage A	Analog Input
Operational Amplifier - OPAMP
OA[2:0]NEG	OPAMP Negative Inputs	Analog Input
OA[2:0]POS	OPAMP Positive Inputs	Analog Input
OA0OUT / OA2OUT	OPAMP Outputs	Analog Output
Peripheral Touch Controller - PTC
XY[19:0]	X-lines and Y-lines	Digital Output (X-line) /Analog I/O (Y-line)
Custom Control Logic - CCL
IN[5:0]	Inputs to lookup table	Digital Input
OUT[1:0]	Outputs from lookup table	Digital Output
External Interrupt Controller - EIC
EXTINT[7:0]	External Interrupts Pins	Digital Input
NMI	Non-Maskable Interrupt Pin	Digital Input
General Purpose I/O - PORT
PA11-PA00 / PA19-PA14 / PA25-PA22 / PA27 / PA31-PA30	General Purpose I/O Pin in Port A	Digital I/O
Reset Controller - RSTC
RESET	External Reset Pin (Active Level: LOW)	Digital Input
Debug Service Unit - DSU
SWCLK	Serial Wire Clock	Digital Input
SWDIO	Serial Wire Bidirectional Data Pin	Digital I/O

VREFA is shared between the ADC and DAC peripherals.