The table below shows the connections between the target and the debugger section. All connections between the target and the debugger are tri-stated as long as the debugger is not actively using the interface, hence there is little contamination of the signals, the pins can be configured to anything the user wants.
For further information on how to use the capabilities of the onboard debugger, see Section Curiosity Nano.
| ATmega4809 Pin | Debugger Pin | Function | Shared Functionality |
|---|---|---|---|
| PB1 | CDC TX | UART RX (ATmega4809 RX line) | Edge connector |
| PB0 | CDC RX | UART TX (ATmega4809 TX line) | Edge connector |
| UPDI | DBG0 | UPDI | |
| PF3 | DBG1 | GPIO | Edge connector |
| PF2 | DBG2 | GPIO | Edge connector |
| PF6 | DBG3 | RESET/GPIO | User switch |
| VCC_TARGET | VCC_LEVEL | 1.8-5.1V Supply | |
| GND | GND | Common ground |