59.2.1 Crystal Oscillators

Signal Name Recommended Pin Connection Description
XIN

XOUT

3 to 20 MHz Crystal Oscillator in Normal Mode

Crystals between 3 and 20 MHz

USB High/Full Speed Host/Device peripherals require a 12 or 16 MHz clock.

Capacitors on XIN and XOUT

(Crystal Load Capacitance dependent)

Crystal Load Capacitance to check (CCRYSTAL).

Example: for a 12 MHz crystal with a load capacitance of CCRYSTAL = 15 pF, external capacitors are required:

CLEXT = 12 pF.

Refer to 57 Electrical Characteristics for SAM V70/V71.

XIN

XOUT

3 to 20 MHz Crystal Oscillator in Bypass Mode

XIN: external clock source

XOUT: can be left unconnected

USB High/Full speed Host/Device peripherals require a 12 or 16 MHz clock.

VDDIO square wave signal

External clock source up to 20 MHz

Duty Cycle: 40 to 60%

Refer to 57 Electrical Characteristics for SAM V70/V71.

XIN

XOUT

3 to 20 MHz Crystal Oscillator Disabled

XIN: can be left unconnected

XOUT: can be left unconnected

USB High/Full-speed Host/Device peripherals are not functional with Main RC oscillator.

Typical nominal frequency 12 MHz

(Main RC Oscillator)

Duty Cycle: 45 to 55%

Refer to 57 Electrical Characteristics for SAM V70/V71.

XIN32

XOUT32

Slow Clock Oscillator

32.768 kHz Crystal

Capacitors on XIN32 and XOUT32

(Crystal Load Capacitance dependent)

Crystal load capacitance to check (CCRYSTAL32).

Example: for a 32.768 kHz crystal with a load capacitance of CCRYSTAL32 = 7 pF, external capacitors are required:

CLEXT32 = 11 pF.

Refer to 57 Electrical Characteristics for SAM V70/V71.

XIN32

XOUT32

Slow Clock Oscillator in Bypass Mode

XIN32: external clock source

XOUT32: can be left unconnected

VDDIO square wave signal

External clock source up to 44 kHz

Duty Cycle: 40 to 60%

Refer to 57 Electrical Characteristics for SAM V70/V71.

XIN32

XOUT32

Slow Clock Oscillator Disabled

XIN32: can be left unconnected

XOUT32: can be left unconnected

Typical nominal frequency 32 kHz (internal 32 kHz RC oscillator)

Duty Cycle: 45 to 55%

Refer to 57 Electrical Characteristics for SAM V70/V71.