Note:
1.
Actual startup time is 1 OSCULP32K cycle + 3 XOSC cycles.
2.
The given time neglects the three XOSC cycles before OSCULP32K cycle.
Bit 11 – AMPGC: Automatic Amplitude Gain Control
Note:
This bit must be set only after the XOSC has settled, indicated by the XOSC Ready flag in the
Status register (STATUS.XOSCRDY).
Value
Description
0
The automatic amplitude gain control is disabled.
1
The automatic amplitude gain control is enabled. Amplitude gain will be automatically
adjusted during Crystal Oscillator operation.
Bits 10:8 – GAIN[2:0]: Oscillator Gain
These bits select the gain for the oscillator. The listed maximum frequencies are recommendations, and
might vary based on capacitive load and crystal characteristics. Those bits must be properly configured
even when the Automatic Amplitude Gain Control is active.
Value
Recommended Max Frequency [MHz]
0x0
2
0x1
4
0x2
8
0x3
16
0x4
30
0x5-0x7
Reserved
Bit 7 – ONDEMAND: On Demand Control
The On Demand operation mode allows the oscillator to be enabled or disabled, depending on peripheral
clock requests.
If the ONDEMAND bit has been previously written to '1', the oscillator will be running only when requested
by a peripheral. If there is no peripheral requesting the oscillator’s clock source, the oscillator will be in a
disabled state.
If On Demand is disabled, the oscillator will always be running when enabled.
In standby sleep mode, the On Demand operation is still active.
Value
Description
0
The oscillator is always on, if enabled.
1
The oscillator is enabled when a peripheral is requesting the oscillator to be used as a clock
source. The oscillator is disabled if no peripheral is requesting the clock source.
Bit 6 – RUNSTDBY: Run in Standby
This bit controls how the XOSC behaves during standby sleep mode, together with the ONDEMAND bit:
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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