22.8.7. 32KHz External Crystal Oscillator (XOSC32K) Control
Name:
XOSC32K
Offset:
0x14
Reset:
0x00000080
Property:
PAC Write-Protection
Bit
15
14
13
12
11
10
9
8
WRTLOCK
STARTUP[2:0]
Access
R/W
R/W
R/W
R/W
Reset
0
0
0
0
Bit
7
6
5
4
3
2
1
0
ONDEMAND
RUNSTDBY
EN1K
EN32K
XTALEN
ENABLE
Access
R/W
R/W
R/W
R/W
R/W
R/W
Reset
1
0
0
0
0
0
Bit 12 – WRTLOCK: Write Lock
This bit locks the XOSC32K register for future writes, effectively freezing the XOSC32K configuration.
Value
Description
0
The XOSC32K configuration is not locked.
1
The XOSC32K configuration is locked.
Bits 10:8 – STARTUP[2:0]: Oscillator Start-Up Time
These bits select the start-up time for the oscillator.
The OSCULP32K oscillator is used to clock the start-up counter.
Table 22-2. Start-Up Time for 32KHz External Crystal Oscillator
STARTUP[2:0] Number of OSCULP32K
Clock Cycles
Number of XOSC32K
Clock Cycles
Approximate Equivalent
Time
[s]
0x0
2048
3
0.06
0x1
4096
3
0.13
0x2
16384
3
0.5
0x3
32768
3
1
0x4
65536
3
2
0x5
131072
3
4
0x6
262144
3
8
0x7
-
-
Reserved
Note:
1.
Actual Start-Up time is 1 OSCULP32K cycle + 3 XOSC32K cycles.
2.
The given time assumes an XTAL frequency of 32.768kHz.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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