Warning:
Writing the FUSE bit to 0 enables modification of all fuses in the ATmega168PB.
Setting wrong fuse settings may render the mEDBG not usable on the ATmega168PB Xplained
Mini. As an example; if an invalid clock setting is set, a recovery may require an external
debugger.
3.3
mEDBG Firmware Upgrade and Manual Bootloader Entry
The mEDBG firmware is updated through the programming dialog in Atmel Studio.
If you are unable to upgrade the mEDBG firmware on your ATmega168PB Xplained Mini, you can try the
command line utility
atfw.exe
provided with the Atmel Studio.
atfw.exe
is located in the
atbackend
folder in
your Atmel Studio install location.
To manually upgrade the firmware, run the following command:
atfw.exe -t medbg -a ..\tools\ mEDBG\medbg_fw.zip
If
atfw.exe
is unable to find the mEDBG it may be required to force the ATmega32U4 (mEDBG) to enter
its bootloader. To force the bootloader entry, short-circuit the BOOT pads (J102) and toggle power to the
ATmega168PB Xplained Mini board. Run the atfw command above. When the firmware is upgraded,
remove the power from the kit and remove the short-circuit of J102.
Figure 3-2. Force Boot Jumper
ATmega168PB Xplained Mini
©
2017 Microchip Technology Inc.
User Guide
DS50002636A-page 14
