Writing the OSCLOCK Fuse in FUSE.OSCCFG to '1' Prevents Automatic Loading of Calibration Values

Writing the OSCLOCK fuse in FUSE.OSCCFG to ‘1’ prevents the automatic loading of calibration values from the signature row. The device will run with an uncalibrated OSC20M oscillator.

Work Around

Do not use OSCLOCK for locking the oscillator calibration value. The oscillator calibration value can be locked by writing LOCKEN in CLKCTRL.MCLKLOCK to ‘1’ when using the OSC20M oscillator as the Main Clock source.

Affected Silicon Revisions

Rev. C