Medbg Configuration - Microchip Technology ATmega328P Xplained Mini Manual

Figure 3-1. External Clock Footprint
The mEDBG CPU clock frequency depends on the selected voltage, see the table below.
Table 3-2. CPU Clock vs. Voltage
Target Voltage
3.3V
5.0V
3.2

mEDBG Configuration

The operation of the mEDBG can be configured by writing registers in the mEDBG. No configuration is required for
default operation.
3.2.1 mEDBG Low-Power Modes
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.
Table 3-3. Low Power Modes Operation
Mode
EOF
LOWP
Factory settings
3.2.2 mEDBG Fuse Filter
The mEDBG does not initially allow users to program all fuses of the target device through Atmel Studio, as a filter is
implemented to protect certain fuses. The protected fuses are different for every product using the mEDBG and are
typically clock related fuses that could be set to invalid configurations.
The fuse protection can be disabled by writing the FUSE bit to '0'.
©
2020 Microchip Technology Inc.
External CLK COM Port
disabled disabled
forced 1 MHz enabled
enabled enabled
ATmega328P Xplained Mini
mEDBG CPU Clock
8 MHz
16 MHz
ISP/dW Program
disabled
useless
enabled
User Guide
Xplained Mini
ISP/dW Debug
disabled
useless
enabled
DS50002659B-page 11