Curiosity Nano; Onboard Debugger; Virtual Com Port - Microchip Technology ATmega4809 Curiosity Nano User Manual

3.

Curiosity Nano

Curiosity Nano is an evaluation platform that provides a set of small boards with access to most of the
microcontrollers I/Os. The platform consists of a series of low pin-count microcontroller (MCU) boards,
which are integrated with Atmel Studio/Microchip MPLAB
notes, data sheets, and example code. The platform features a Virtual COM port (CDC) for serial
communication to a host PC and a Data Gateway Interface (DGI) GPIO.
3.1

Onboard Debugger

ATmega4809 Curiosity Nano contains an onboard debugger for programming and debugging. The
onboard debugger is a composite USB device of several interfaces: a debugger, a mass storage device,
a data gateway, and a Virtual COM port (CDC).
Together with Atmel Studio/Microchip MPLAB
debug the ATmega4809.
A Data Gateway Interface (DGI) is available for use with the logic analyzer channels for code
instrumentation, to visualize program flow. DGI GPIOs can be graphed using the
The Virtual COM port is connected to a UART on the ATmega4809 and provides an easy way to
communicate with the target application through terminal software.
The onboard debugger controls one 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. Onboard Debugger LED Control
Operation Mode
Boot loader mode
Power-up
Normal operation
Programming
Fault
Sleep/Off
3.1.1

Virtual COM Port

A general purpose USB serial bridge between a host PC and a target device.
3.1.1.1 Overview
The debugger implements a composite USB device that includes a standard Communications Device
Class (CDC) interface, which appears on the host as a Virtual COM Port. The CDC can be used to
stream arbitrary data in both directions between the host and the target: characters sent from the host will
appear in UART form on the CDC TX pin, and UART characters sent into the CDC RX pin will be sent
back to the host.
©
2018 Microchip Technology Inc.
ATmega4809 Curiosity Nano
®
X to present relevant user guides, application
®
X, the onboard debugger interface can program and
Status LED
LED blink at 1 Hz during power up.
LED is lit - constant.
LED is lit - constant.
Activity indicator; the LED flashes slowly during
programming/debugging.
The LED flashes fast if a power fault is detected.
LED is off. The onboard debugger is either in Sleep
mode or powered down. This can occur if the kit is
externally powered.
User Guide
Curiosity Nano
Data Visualizer.
DS50002804A-page 6