Two modes enable the mEDBG to save power when connected to an external power source.
EOF mode, where the mEDBG is disabled. When enabled, the ATmega32U4 will enter sleep mode if the USB does not enumerate within 5 seconds of power-up. In this mode, the external clock is not available to the target MCU.
LOWP mode, where the mEDBG is set to run at 1 MHz. Saving power while maintaining the USB connection for the COM port. The external clock will be 1 MHz.
| Mode | External CLK | COM Port | ISP/dW Program | ISP/dW Debug |
|---|---|---|---|---|
| EOF | disabled | disabled | disabled | disabled |
| LOWP | forced 1 MHz | enabled | useless | useless |
| Factory settings | enabled | enabled | enabled | enabled |