Data Sheet

184
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
16.8.6 32kHz External Crystal Oscillator (XOSC32K) Control
Name: XOSC32K
Offset: 0x14
Reset: 0x0080
Property: Write-Protected
z Bits 15:13 – Reserved
These bits are unused and reserved for future use. For compatibility with future devices, always write these bits to
zero when this register is written. These bits will always return zero when read.
z Bit 12 – WRTLOCK: Write Lock
This bit locks the XOSC32K register for future writes to fix the XOSC32K configuration.
0: The XOSC32K configuration is not locked.
1: The XOSC32K configuration is locked.
z Bit 11 – Reserved
This bit is unused and reserved for future use. For compatibility with future devices, always write this bit to zero
when this register is written. This bit will always return zero when read.
z Bits 10:8 – STARTUP[2:0]: Oscillator Start-Up Time
These bits select the start-up time for the oscillator according to Table 16-9.
The OSCULP32K oscillator is used to clock the start-up counter.
Bit 151413121110 9 8
WRTLOCK STARTUP[2:0]
Access R R R R/W R R/W R/W R/W
Reset00000000
Bit 76543210
ONDEMAND RUNSTDBY AAMPEN EN32K XTALEN ENABLE
Access R/W R/W R/W R R/W R/W R/W R
Reset10000000