3.1 On-Board Debugger Overview

ATmega4809 Curiosity Nano contains an on-board debugger for programming and debugging. The on-board debugger is a composite USB device consisting of several interfaces:
  • A debugger that can program and debug the ATmega4809 in both MPLAB® X IDE and Atmel Studio 7
  • A mass storage device that allows drag-and-drop programming of the ATmega4809
  • A virtual serial port (CDC) that is connected to a Universal Asynchronous Receiver/Transmitter (UART) on the ATmega4809, and provides an easy way to communicate with the target application through terminal software
  • A Data Gateway Interface (DGI) for code instrumentation with logic analyzer channels (debug GPIO) to visualize program flow

The on-board debugger controls a Power and Status LED (marked PS) on the ATmega4809 Curiosity Nano board. The table below shows how the LED is controlled in different operation modes.

Table 3-1. On-Board Debugger LED Control
Operation ModePower and Status LED
Boot Loader modeThe LED blinks slowly during power-up
Power-upThe LED is ON
Normal operationThe LED is ON
ProgrammingActivity indicator: The LED blinks slowly during programming/debugging
Drag-and-drop programming
Success:
The LED blinks slowly for 2 sec.
Failure:
The LED blinks rapidly for 2 sec.
FaultThe LED blinks rapidly if a power fault is detected
Sleep/OffThe LED is OFF. The on-board debugger is either in a sleep mode or powered down. This can occur if the board is externally powered.
Info: Slow blinking is approximately 1 Hz, and rapid blinking is approximately 5 Hz.