Microchip AVR128DA48 User Manual

5 (1)
Microchip AVR128DA48 User Manual

AVR128DA48 Curiosity Nano

AVR128DA48 Curiosity Nano User Guide

Preface

The AVR128DA48 Curiosity Nano Evaluation Kit is a hardware platform to evaluate microcontrollers in the AVR-DA family. This board has the AVR128DA48 microcontroller (MCU) mounted.

Supported by Atmel Studio and Microchip MPLAB® X Integrated Development Environments (IDEs), the board provides easy access to the features of the AVR128DA48 to explore how to integrate the device into a custom design.

The Curiosity Nano series of evaluation boards include an on-board debugger. No external tools are necessary to program and debug the AVR128DA48.

MPLAB® X IDE and Atmel Studio - Software to discover, configure, develop, program, and debug Microchip microcontrollers.

Code examples in Atmel START - Get started with code examples or generate drivers for a custom application.

Code examples on GitHub - Get started with code examples.

AVR128DA48 website - Find documentation, datasheets, sample, and purchase microcontrollers.

AVR128DA48 Curiosity Nano website - Kit information, latest user guide and design documentation.

 

 

 

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 1

 

 

 

 

 

AVR128DA48 Curiosity Nano

 

 

 

 

 

 

Table of Contents

 

 

 

 

 

 

 

 

 

 

 

Preface...........................................................................................................................................................

 

 

 

1

 

 

1.

Introduction.............................................................................................................................................

 

 

4

 

 

 

1.1.

Features.......................................................................................................................................

 

 

4

 

 

 

1.2.

Kit Overview.................................................................................................................................

 

4

 

 

2.

Getting Started........................................................................................................................................

 

 

5

 

 

 

2.1.

Quick Start....................................................................................................................................

 

5

 

 

 

2.2. Design Documentation and Relevant Links.................................................................................

5

 

 

3.

Curiosity Nano.........................................................................................................................................

 

 

7

 

 

 

3.1.

On-Board Debugger Overview.....................................................................................................

7

 

 

 

 

3.1.1.

Debugger.......................................................................................................................

 

7

 

 

 

 

3.1.2. Virtual Serial Port (CDC)................................................................................................

8

 

 

 

 

 

3.1.2.1.

Overview.....................................................................................................

8

 

 

 

 

 

3.1.2.2.

Operating System Support..........................................................................

8

 

 

 

 

 

3.1.2.3.

Limitations...................................................................................................

9

 

 

 

 

 

3.1.2.4.

Signaling......................................................................................................

9

 

 

 

 

 

3.1.2.5.

Advanced Use.............................................................................................

9

 

 

 

 

3.1.3.

Mass Storage Device...................................................................................................

10

 

 

 

 

 

3.1.3.1.

Mass Storage Device Implementation.......................................................

10

 

 

 

 

 

3.1.3.2.

Fuse Bytes.................................................................................................

11

 

 

 

 

 

3.1.3.3.

Limitations of Drag-and-Drop Programming..............................................

11

 

 

 

 

 

3.1.3.4.

Special Commands...................................................................................

11

 

 

 

 

3.1.4. Data Gateway Interface (DGI).....................................................................................

12

 

 

 

 

 

3.1.4.1.

Debug GPIO..............................................................................................

12

 

 

 

 

 

3.1.4.2.

Timestamping............................................................................................

12

 

 

 

3.2. Curiosity Nano Standard Pinout.................................................................................................

13

 

 

 

3.3.

Power Supply.............................................................................................................................

 

13

 

 

 

 

3.3.1.

Target Regulator..........................................................................................................

14

 

 

 

 

3.3.2.

External Supply............................................................................................................

15

 

 

 

 

3.3.3.

VBUS Output Pin.........................................................................................................

16

 

 

 

 

3.3.4.

Power Supply Exceptions............................................................................................

16

 

 

 

3.4.

Low Power Measurement...........................................................................................................

17

 

 

 

3.5.

Programming External Microcontrollers.....................................................................................

18

 

 

 

 

3.5.1.

Supported Devices......................................................................................................

18

 

 

 

 

3.5.2.

Software Configuration................................................................................................

18

 

 

 

 

3.5.3.

Hardware Modifications...............................................................................................

19

 

 

 

 

3.5.4. Connecting to External Microcontrollers......................................................................

20

 

 

 

3.6.

Connecting External Debuggers................................................................................................

21

 

 

4.

Hardware User Guide...........................................................................................................................

 

24

 

 

 

4.1.

Connectors.................................................................................................................................

 

24

 

 

 

 

4.1.1. AVR128DA48 Curiosity Nano Pinout...........................................................................

24

 

 

 

 

4.1.2.

Using Pin Headers.......................................................................................................

24

 

 

 

4.2.

Peripherals.................................................................................................................................

 

25

 

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 2

AVR128DA48 Curiosity Nano

 

 

4.2.1.

LED..............................................................................................................................

 

25

 

 

4.2.2.

Mechanical Switch.......................................................................................................

25

 

 

4.2.3.

Crystal..........................................................................................................................

 

25

 

 

4.2.4.

On-Board Debugger Implementation...........................................................................

26

 

 

 

4.2.4.1.

On-Board Debugger Connections.............................................................

26

5. Hardware Revision History and Known Issues.....................................................................................

27

 

5.1. Identifying Product ID and Revision...........................................................................................

27

 

5.2.

Revision 3...................................................................................................................................

 

27

6.

Document Revision History...................................................................................................................

 

28

7.

Appendix...............................................................................................................................................

 

 

29

 

7.1.

Schematic...................................................................................................................................

 

29

 

7.2.

Assembly Drawing......................................................................................................................

 

31

 

7.3. Curiosity Nano Base for Click boards......................................................................................

32

 

7.4. Disconnecting the On-board Debugger......................................................................................

33

 

7.5. Getting Started with IAR.............................................................................................................

34

The Microchip Website.................................................................................................................................

 

37

Product Change Notification Service............................................................................................................

37

Customer Support........................................................................................................................................

 

 

37

Microchip Devices Code Protection Feature................................................................................................

37

Legal Notice.................................................................................................................................................

 

 

37

Trademarks..................................................................................................................................................

 

 

38

Quality Management System.......................................................................................................................

 

38

Worldwide Sales and Service.......................................................................................................................

 

39

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 3

AVR128DA48 Curiosity Nano

Introduction

1.Introduction

1.1Features

AVR128DA48-I/PT Microcontroller

One Yellow User LED

One Mechanical User Switch

One 32.768 kHz Crystal

On-Board Debugger:

Board identification in Atmel Studio/Microchip MPLAB® X IDE

One green power and status LED

Programming and debugging

Virtual serial port (CDC)

Two debug GPIO channels (DGI GPIO)

USB Powered

Adjustable Target Voltage:

MIC5353 LDO regulator controlled by the on-board debugger

1.8-5.1V output voltage (limited by USB input voltage)

500 mA maximum output current (limited by ambient temperature and output voltage)

1.2Kit Overview

The Microchip AVR128DA48 Curiosity Nano Evaluation Kit is a hardware platform to evaluate the AVR128DA48 microcontroller.

Figure 1-1. AVR128DA48 Curiosity Nano Evaluation Kit Overview

Micro USB

Power/Status

Debugger

32.768 kHz

AVR128DA48

User LED

User Switch

Connector

LED

Crystal

MCU

(LED0)

(SW0)

 

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 4

AVR128DA48 Curiosity Nano

Getting Started

2.Getting Started

2.1Quick Start

Steps to start exploring the AVR128DA48 Curiosity Nano Board:

1.Download Atmel Studio/Microchip MPLAB® X IDE.

2.Launch Atmel Studio/Microchip MPLAB® X IDE.

3.Optional: Use MPLAB® Code Configurator or Atmel START to generate drivers and examples.

4.Write your application code.

5.Connect a USB cable (Standard-A to Micro-B or Micro-AB) between the PC and the debug USB port on the board.

Driver Installation

When the board is connected to your computer for the first time, the operating system will perform a driver software installation. The driver file supports both 32and 64-bit versions of Microsoft® Windows® XP, Windows Vista®, Windows 7, Windows 8, and Windows 10. The drivers for the board are included with Atmel Studio/Microchip MPLAB® X IDE.

Kit Window

Once the board is powered, the green status LED will be lit, and Atmel Studio/Microchip MPLAB® X IDE will autodetect which boards are connected. Atmel Studio/Microchip MPLAB® X IDE will present relevant information like data sheets and board documentation. The AVR128DA48 device on the AVR128DA48 Curiosity Nano Board is programmed and debugged by the on-board debugger and, therefore, no external programmer or debugger tool is required.

Tip:  The Kit Window can be opened in MPLAB X IDE through the menu bar Window > Kit Window.

2.2Design Documentation and Relevant Links

The following list contains links to the most relevant documents and software for the AVR128DA48 Curiosity Nano Board:

MPLAB® X IDE - MPLAB X IDE is a software program that runs on a PC (Windows®, Mac OS®, Linux®) to develop applications for Microchip microcontrollers and digital signal controllers. It is called an Integrated Development Environment (IDE) because it provides a single integrated “environment” to develop code for embedded microcontrollers.

Atmel Studio - Free IDE for the development of C/C++ and assembler code for microcontrollers.

IAR Embedded Workbench® for AVR® - This is a commercial C/C++ compiler that is available for AVR microcontrollers. There is a 30-day evaluation version as well as a 4 KB code-size-limited kick-start version available from their website.

MPLAB® Code Configurator - MPLAB Code Configurator (MCC) is a free software plug-in that provides a graphical interface to configure peripherals and functions specific to your application.

Atmel START - Atmel START is an online tool that hosts code examples, helps the user to select and configure software components, and tailor your embedded application in a usable and optimized manner.

Microchip Sample Store - Microchip sample store where you can order samples of devices.

MPLAB Data Visualizer - MPLAB Data Visualizer is a program used for processing and visualizing data. The Data Visualizer can receive data from various sources such as serial ports and on-board debugger’s Data Gateway Interface, as found on Curiosity Nano and Xplained Pro boards.

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 5

AVR128DA48 Curiosity Nano

Getting Started

Studio Data Visualizer - Studio Data Visualizer is a program used for processing and visualizing data. The Data Visualizer can receive data from various sources such as serial ports, on-board debugger’s Data Gateway Interface as found on Curiosity Nano and Xplained Pro boards, and power data from the Power Debugger.

Microchip PIC® and AVR Examples - Microchip PIC and AVR Device Examples is a collection of examples and labs that use Microchip development boards to showcase the use of PIC and AVR device peripherals.

Microchip PIC® and AVR Solutions - Microchip PIC and AVR Device Solutions contains complete applications for use with Microchip development boards, ready to be adapted and extended.

AVR128DA48 Curiosity Nano website - Kit information, latest user guide and design documentation.

AVR128DA48 Curiosity Nano on microchipDIRECT - Purchase this kit on microchipDIRECT.

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 6

AVR128DA48 Curiosity Nano

Curiosity Nano

3.Curiosity Nano

Curiosity Nano is an evaluation platform 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 with on-board debuggers, which are integrated with Atmel Studio/Microchip MPLAB® X IDE. Each board is identified in the IDE. When plugged in, a Kit Window is displayed with links to key documentation, including relevant user guides, application notes, data sheets, and example code. Everything is easy to find. The on-board debugger features a virtual serial port (CDC) for serial communication to a host PC and a Data Gateway Interface (DGI) with debug GPIO pin(s).

3.1On-Board Debugger Overview

AVR128DA48 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 AVR128DA48 in Atmel Studio/Microchip MPLAB® X IDE

A mass storage device that allows drag-and-drop programming of the AVR128DA48

A virtual serial port (CDC) that is connected to a Universal Asynchronous Receiver/Transmitter (UART) on the AVR128DA48, 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 AVR128DA48 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 Mode

 

Power and Status LED

 

 

 

 

Boot Loader mode

The LED blinks slowly during power-up.

 

 

 

 

 

Power-up

The LED is ON.

 

 

 

 

 

 

Normal operation

The LED is ON.

 

 

 

 

 

Programming

Activity indicator: The LED blinks slowly during programming/debugging.

 

 

 

 

 

Drag-and-drop

Success:

The LED blinks slowly for 2 sec.

 

programming

 

Failure:

The LED blinks rapidly for 2 sec.

 

 

 

 

 

 

Fault

The LED blinks rapidly if a power fault is detected.

 

 

 

 

Sleep/Off

The 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.

3.1.1Debugger

The on-board debugger on the AVR128DA48 Curiosity Nano Board appears as a Human Interface Device (HID) on the host computer’s USB subsystem. The debugger supports full-featured programming and debugging of the AVR128DA48 using Atmel Studio/Microchip MPLAB® X IDE, as well as some third-party IDEs.

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 7

AVR128DA48 Curiosity Nano

Curiosity Nano

Remember:  Keep the debugger’s firmware up-to-date. Firmware upgrades are done automatically when using Atmel Studio/Microchip MPLAB® X IDE.

3.1.2Virtual Serial Port (CDC)

The virtual serial port (CDC) is a general purpose serial bridge between a host PC and a target device.

3.1.2.1Overview

The on-board debugger implements a composite USB device that includes a standard Communications Device Class (CDC) interface, which appears on the host as a virtual serial port. The CDC can be used to stream arbitrary data in both directions between the host computer and the target: All characters sent through the virtual serial port on the host computer will be transmitted as UART on the debugger’s CDC TX pin, and UART characters captured on the debugger’s CDC RX pin will be returned to the host computer through the virtual serial port.

Figure 3-1. CDC Connection

PC

Terminal

Software

Terminal

Debugger

Target

Target MCU

Send

 

CDC TX

Receive

UART RX

 

USB

 

 

CDC RX

 

UART TX

Terminal

 

Target

 

 

 

Receive

 

 

Send

 

Info:  As shown in Figure 3-1, the debugger’s CDC TX pin is connected to a UART RX pin on the target for receiving characters from the host computer. Similarly, the debugger’s CDC RX pin is connected to a UART TX pin on the target for transmitting characters to the host computer.

3.1.2.2Operating System Support

On Windows machines, the CDC will enumerate as Curiosity Virtual COM Port and appear in the Ports section of the Windows Device Manager. The COM port number can also be found there.

Info:  On older Windows systems, a USB driver is required for CDC. This driver is included in installations of Atmel Studio/Microchip MPLAB® X IDE.

On Linux machines, the CDC will enumerate and appear as /dev/ttyACM#.

Info:  tty* devices belong to the “dialout” group in Linux, so it may be necessary to become a member of that group to have permissions to access the CDC.

On MAC machines, the CDC will enumerate and appear as /dev/tty.usbmodem#. Depending on which terminal program is used, it will appear in the available list of modems as usbmodem#.

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 8

AVR128DA48 Curiosity Nano

Curiosity Nano

Info:  For all operating systems: Be sure to use a terminal emulator that supports DTR signaling. See 3.1.2.4 Signaling.

3.1.2.3Limitations

Not all UART features are implemented in the on-board debugger CDC. The constraints are outlined here:

Baud rate: Must be in the range of 1200 bps to 500 kbps. Any baud rate outside this range will be set to the closest limit, without warning. Baud rate can be changed on-the-fly.

Character format: Only 8-bit characters are supported.

Parity: Can be odd, even, or none.

Hardware flow control: Not supported.

Stop bits: One or two bits are supported.

3.1.2.4Signaling

During USB enumeration, the host OS will start both communication and data pipes of the CDC interface. At this point, it is possible to set and read back the baud rate and other UART parameters of the CDC, but data sending and receiving will not be enabled.

When a terminal connects on the host, it must assert the DTR signal. As this is a virtual control signal implemented on the USB interface, it is not physically present on the board. Asserting the DTR signal from the host will indicate to the on-board debugger that a CDC session is active. The debugger will then enable its level shifters (if available), and start the CDC data send and receive mechanisms.

Deasserting the DTR signal will not disable the level shifters but disable the receiver so no further data will be streamed to the host. Data packets that are already queued up for sending to the target will continue to be sent out, but no further data will be accepted.

Remember:  Set up the terminal emulator to assert the DTR signal. Without the signal, the on-board debugger will not send or receive any data through its UART.

Tip:  The on-board debugger’s CDC TX pin will not be driven until the CDC interface is enabled by the host computer. Also, there are no external pull-up resistors on the CDC lines connecting the debugger and the target, which means that during power-up, these lines are floating. To avoid any glitches resulting in unpredictable behavior like framing errors, the target device should enable the internal pull-up resistor on the pin connected to the debugger’s CDC TX pin.

3.1.2.5Advanced Use

CDC Override Mode

In normal operation, the on-board debugger is a true UART bridge between the host and the device. However, in certain use cases, the on-board debugger can override the basic operating mode and use the CDC TX and RX pins for other purposes.

Dropping a text file into the on-board debugger’s mass storage drive can be used to send characters out of the debugger’s CDC TX pin. The filename and extension are trivial, but the text file must start with the characters:

CMD:SEND_UART=

The maximum message length is 50 characters – all remaining data in the frame are ignored.

The default baud rate used in this mode is 9600 bps, but if the CDC is already active or has been configured, the previously used baud rate still applies.

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 9

AVR128DA48 Curiosity Nano

Curiosity Nano

USB-Level Framing Considerations

Sending data from the host to the CDC can be done byte-wise or in blocks, which will be chunked into 64-byte USB frames. Each such frame will be queued up for sending to the debugger’s CDC TX pin. Transferring a small amount of data per frame can be inefficient, particularly at low baud rates, because the on-board debugger buffers frames and not bytes. A maximum of four 64-byte frames can be active at any time. The on-board debugger will throttle the incoming frames accordingly. Sending full 64-byte frames containing data is the most efficient method.

When receiving data on the debugger’s CDC RX pin, the on-board debugger will queue up the incoming bytes into 64-byte frames, which are sent to the USB queue for transmission to the host when they are full. Incomplete frames are also pushed to the USB queue at approximately 100 ms intervals, triggered by USB start-of-frame tokens. Up to eight 64-byte frames can be active at any time.

If the host (or the software running on it) fails to receive data fast enough, an overrun will occur. When this happens, the last-filled buffer frame will be recycled instead of being sent to the USB queue, and a full frame of data will be lost. To prevent this occurrence, the user must ensure that the CDC data pipe is being read continuously, or the incoming data rate must be reduced.

3.1.3Mass Storage Device

The on-board debugger includes a simple Mass Storage Device implementation, which is accessible for read/write operations via the host operating system to which it is connected.

It provides:

Read access to basic text and HTML files for detailed kit information and support

Write access for programming Intel® HEX formatted files into the target device’s memory

Write access for simple text files for utility purposes

3.1.3.1Mass Storage Device Implementation

The on-board debugger implements a highly optimized variant of the FAT12 file system that has several limitations, partly due to the nature of FAT12 itself and optimizations made to fulfill its purpose for its embedded application.

The Curiosity Nano USB Device is USB Chapter 9-compliant as a mass storage device but does not, in any way, fulfill the expectations of a general purpose mass storage device. This behavior is intentional.

When using the Windows operating system, the on-board debugger enumerates as a Curiosity Nano USB Device that can be found in the disk drives section of the device manager. The CURIOSITY drive appears in the file manager and claims the next available drive letter in the system.

The CURIOSITY drive contains approximately one MB of free space. This does not reflect the size of the target device’s Flash in any way. When programming an Intel® HEX file, the binary data are encoded in ASCII with metadata providing a large overhead, so one MB is a trivially chosen value for disk size.

It is not possible to format the CURIOSITY drive. When programming a file to the target, the filename may appear in the disk directory listing. This is merely the operating system’s view of the directory, which, in reality, has not been updated. It is not possible to read out the file contents. Removing and replugging the board will return the file system to its original state, but the target will still contain the application that has been previously programmed.

To erase the target device, copy a text file starting with “CMD:ERASE” onto the disk.

By default, the CURIOSITY drive contains several read-only files for generating icons as well as reporting status and linking to further information:

AUTORUN.ICO – icon file for the Microchip logo

AUTORUN.INF – system file required for Windows Explorer to show the icon file

KIT-INFO.HTM – redirect to the development board website

KIT-INFO.TXT – a text file containing details about the board’s debugger firmware version, board name, USB serial number, device, and drag-and-drop support

STATUS.TXT – a text file containing the programming status of the board

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 10

AVR128DA48 Curiosity Nano

Curiosity Nano

Info:  STATUS.TXT is dynamically updated by the on-board debugger. The contents may be cached by the OS and, therefore, do not reflect the correct status.

3.1.3.2Fuse Bytes

Fuse Bytes (AVR® MCU Targets)

When doing drag-and-drop programming, the debugger masks out fuse bits that attempt to disable Unified Program and Debug Interface (UPDI). This means that the UPDI pin cannot be used in its reset or GPIO modes; selecting one of the alternative functions on the UPDI pin would render the device inaccessible without using an external debugger capable of high-voltage UPDI activation.

3.1.3.3Limitations of Drag-and-Drop Programming

Lock Bits

Lock bits included in the hex file will be ignored when using drag-and-drop programming. To program lock bits, use Atmel Studio/Microchip MPLAB® X IDE.

Enabling CRC Check in Fuses

It is not advisable to enable the CRC check in the target device’s fuses when using drag-and-drop programming. This because a subsequent chip erase (which does not affect fuse bits) will effect a CRC mismatch, and the application will fail to boot. To recover a target from this state, a chip erase must be done using Atmel Studio/Microchip MPLAB® X IDE, which will automatically clear the CRC fuses after erasing.

3.1.3.4Special Commands

Several utility commands are supported by copying text files to the mass storage disk. The filename or extension is irrelevant – the command handler reacts to content only.

Table 3-2. Special File Commands

Command Content

Description

 

 

CMD:ERASE

Executes a chip erase of the target

CMD:SEND_UART=

Sends a string of characters to the CDC UART. See “CDC Override Mode”.

CMD:RESET

Resets the target device by entering Programming mode and then exiting

 

Programming mode immediately thereafter. Exact timing can vary according to

 

the programming interface of the target device. (Debugger firmware v1.16 or

 

newer.)

CMD:POWERTOGGLE

Powers down the target and restores power after a 100 ms delay. If external

 

power is provided, this has no effect. (Debugger firmware v1.16 or newer.)

CMD:0V

Powers down the target device by disabling the target supply regulator. If

 

external power is provided, this has no effect. (Debugger firmware v1.16 or

 

newer.)

CMD:3V3

Sets the target voltage to 3.3V. If external power is provided, this has no effect.

 

(Debugger firmware v1.16 or newer.)

CMD:5V0

Sets the target voltage to 5.0V. If external power is provided, this has no effect.

 

(Debugger firmware v1.16 or newer.)

 

 

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 11

AVR128DA48 Curiosity Nano

Curiosity Nano

Info:  The commands listed here are triggered by the content being sent to the mass storage emulated disk, and no feedback is provided in the case of either success or failure.

3.1.4Data Gateway Interface (DGI)

Data Gateway Interface (DGI) is a USB interface for transporting raw and timestamped data between on-board debuggers and host computer-based visualization tools. MPLAB Data Visualizer is used on the host computer to display debug GPIO data. It is available as a plug-in for MPLAB® X IDE or a stand-alone application that can be used in parallel with Atmel Studio/Microchip MPLAB® X IDE.

Although DGI encompasses several physical data interfaces, the AVR128DA48 Curiosity Nano implementation includes logic analyzer channels:

Two debug GPIO channels (also known as DGI GPIO)

3.1.4.1Debug GPIO

Debug GPIO channels are timestamped digital signal lines connecting the target application to a host computer visualization application. They are typically used to plot the occurrence of low-frequency events on a time-axis – for example, when certain application state transitions occur.

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.

3.1.4.2Timestamping

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.

© 2020 Microchip Technology Inc.

User Guide

DS50002971A-page 12

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