The figure below shows the monitoring of the digital state of a mechanical switch connected to a debug GPIO in

MPLAB Data Visualizer.

Figure 3-2. Monitoring Debug GPIO with MPLAB® Data Visualizer

Debug GPIO channels are timestamped, so the resolution of DGI GPIO events is determined by the resolution of the

DGI timestamp module.

Important:  Although bursts of higher-frequency signals can be captured, the useful frequency range of

signals for which debug GPIO can be used is up to about 2 kHz. Attempting to capture signals above this

frequency will result in data saturation and overflow, which may cause the DGI session to be aborted.

3.1.4.2

Timestamping

DGI sources are timestamped as they are captured by the debugger. The timestamp counter implemented in the

Curiosity Nano debugger increments at 2 MHz frequency, providing a timestamp resolution of a half microsecond.

3.2

Curiosity Nano Standard Pinout

The 12 edge connections closest to the USB connector on Curiosity Nano boards have a standardized pinout. The

program/debug pins have different functions depending on the target programming interface, as shown in the table

and figure below.

Table 3-3. Curiosity Nano Standard Pinout

Debugger Signal

Target MCU

Description

ID

—

ID line for extensions

CDC TX

UART RX

USB CDC TX line

CDC RX

UART TX

USB CDC RX line

DBG0

UPDI

Debug data line

DBG1

GPIO1

debug GPIO1

DBG2

GPIO0

debug GPIO0

DBG3

RESET

Reset line

ATtiny1627

Curiosity Nano

© 2020 Microchip Technology Inc.

User Guide

DS40002199A-page 13