Microchip Technology megaAVR 0 Series Manual page 86

9.5.3 Main Clock Lock
Name: MCLKLOCK
Offset: 0x02
Reset: Based on OSCLOCK in FUSE.OSCCFG
Property: Configuration Change Protection
Bit 7
Access
Reset
Bit 0 – LOCKEN Lock Enable
Writing this bit to '1' will lock the CLKCTRL.MCLKCTRLA and CLKCTRL.MCLKCTRLB registers, and, if
applicable, the calibration settings for the current main clock source from further software updates. Once
locked, the CLKCTRL.MCLKLOCK registers cannot be accessed until the next hardware Reset.
This provides protection for the CLKCTRL.MCLKCTRLA and CLKCTRL.MCLKCTRLB registers and
calibration settings for the main clock source from unintentional modification by software.
At Reset, the LOCKEN bit is loaded based on the OSCLOCK bit in FUSE.OSCCFG.
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2018 Microchip Technology Inc.
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Datasheet Preliminary
®
megaAVR 0-Series
Clock Controller (CLKCTRL)
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DS40002015A-page 86
0
LOCKEN
R/W
x