2.3 Project Introduction

To run the example project on ATmega328PB Xplained Mini Kit, program the CFD fuse bit by setting ‘Enabled’ and the Clock Selection Fuse bits by setting ‘Ext. clock; Start-up time PWRDWN/RESET: 6 CK/14 CK + 0 ms’, as shown in the figure below.

Once the fuse settings have been set and the example project firmware image is programmed, the ATmega328PB device on the Xplained board works with the external 16 MHz clock and turns on LED0. Once the external 16 MHz clock is shorted, the ATmega328PBʼs CFD mechanism will detect it. Then, auto-switch to the internal 1 MHz RC oscillator and set the Clock Failure Flag bit, which triggers the LED toggling in this example project, as shown in the figure below.