Data Sheet

181
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
16.8.5 External Multipurpose Crystal Oscillator (XOSC) Control
Name: XOSC
Offset: 0x10
Reset: 0x0080
Property: Write-Protected
z Bits 15:12 – STARTUP[3:0]: Start-Up Time
These bits select start-up time for the oscillator according to the table below.
The OSCULP32K oscillator is used to clock the start-up counter.
Bit 151413121110 9 8
STARTUP[3:0] AMPGC GAIN[2:0]
AccessR/WR/WR/WR/WR/WR/WR/WR/W
Reset00000000
Bit 76543210
ONDEMAND RUNSTDBY XTALEN ENABLE
Access R/W R/W R R R R/W R/W R
Reset10000000
Table 16-7. Start-UpTime for External Multipurpose Crystal Oscillator
STARTUP[3:0]
Number of
OSCULP32K Clock
Cycles
Number of XOSC
Clock Cycles
Approximate Equivalent Time
(1)(2)(3)
0x0 1 3 31µs
0x1 2 3 61µs
0x2 4 3 122µs
0x3 8 3 244µs
0x4 16 3 488µs
0x5 32 3 977µs