Microchip Technology ATmega4809 Xplained Pro User manual

ATmega4809 Xplained Pro
ATmega4809 Xplained Pro
Preface
The ATmega4809 Xplained Pro evaluation kit is a hardware platform to evaluate the ATmega4809 microcontroller.
Supported by the integrated development platform Microchip Studio, the kit provides easy access to the features of
the ATmega4809 and explains how to integrate the device into a custom design.
The Xplained Pro MCU series evaluation kits include an on-board Embedded Debugger (EDBG). No external tools
are necessary to program or debug the ATmega4809.
The Xplained Pro extension kits offer additional peripherals to extend the features of the board and ease the
development of custom designs.
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 1

Table of Contents
Preface........................................................................................................................................................... 1
1. Introduction............................................................................................................................................. 4
1.1. Features....................................................................................................................................... 4
1.2. Kit Overview................................................................................................................................. 4
2. Getting Started........................................................................................................................................ 6
2.1. Xplained Pro Quick Start.............................................................................................................. 6
2.2. Design Documentation and Relevant Links................................................................................. 6
3. Xplained Pro............................................................................................................................................7
3.1. Embedded Debugger................................................................................................................... 7
3.2. Hardware Identification System....................................................................................................7
3.3. Power Sources............................................................................................................................. 8
3.4. Xplained Pro Headers and Connectors........................................................................................8
3.4.1. Xplained Pro Standard Extension Header.....................................................................8
3.4.2. Xplained Pro Power Header.......................................................................................... 9
4. Hardware User Guide............................................................................................................................11
4.1. Power Distribution...................................................................................................................... 11
4.2. Connectors................................................................................................................................. 12
4.2.1. Xplained Pro Standard Extension Headers................................................................. 12
4.2.2. mikroBUS™ Socket...................................................................................................... 15
4.2.3. AVR® Debugger Connector......................................................................................... 16
4.3. Peripherals................................................................................................................................. 16
4.3.1. Crystals........................................................................................................................16
4.3.2. Mechanical Buttons..................................................................................................... 16
4.3.3. LED..............................................................................................................................17
4.3.4. Footprint for CryptoAuthentication™ Devices...............................................................17
4.4. Embedded Debugger Implementation........................................................................................18
4.4.1. UPDI............................................................................................................................ 18
4.4.2. Virtual COM Port..........................................................................................................18
4.4.3. Data Gateway Interface...............................................................................................18
4.5. Kit Modifications......................................................................................................................... 19
4.5.1. Operation at Other Voltages........................................................................................ 22
5. Appendix............................................................................................................................................... 23
5.1. Getting Started with IAR™...........................................................................................................23
6. Hardware Revision History and Known Issues..................................................................................... 25
6.1. Identifying Product ID and Revision........................................................................................... 25
6.2. Revision 6...................................................................................................................................25
6.3. mikroBUS™ Socket and Kit Power Supply..................................................................................25
6.4. Revision 5...................................................................................................................................27
6.5. Revision 4...................................................................................................................................27
6.6. Revision 3...................................................................................................................................27
ATmega4809 Xplained Pro
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 2

7. Document Revision History...................................................................................................................29
The Microchip Website.................................................................................................................................30
Product Change Notification Service............................................................................................................30
Customer Support........................................................................................................................................ 30
Microchip Devices Code Protection Feature................................................................................................ 30
Legal Notice................................................................................................................................................. 31
Trademarks.................................................................................................................................................. 31
Quality Management System....................................................................................................................... 32
Worldwide Sales and Service.......................................................................................................................33
ATmega4809 Xplained Pro
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 3

1. Introduction
1.1 Features
• ATmega4809 microcontroller
• Selectable target voltage
– 3.3V
– 5.0V (USB/external power)
• One mechanical reset/user programmable button
• One mechanical user programmable button
• One yellow user programmable LED
• UDFN8 footprint for Microchip CryptoAuthentication™ devices
• 32.768 kHz crystal
• Three Xplained Pro extension headers
• One mikroBUS™ socket
• 10-pin, 50-mil AVR® Debug Connector with UPDI
• Embedded Debugger
– Auto-ID for board identification in Microchip Studio/MPLAB® X
– One yellow status LED
– One green board power LED
– Symbolic debug of complex data types including scope information
– Programming and debugging, including power measurements
– Data Gateway Interface: SPI, I2C, four GPIOs
– Virtual COM port (CDC)
• USB powered
1.2 Kit Overview
The ATmega4809 Xplained Pro evaluation kit is a hardware platform to evaluate the ATmega4809.
The kit offers a set of features that enables the ATmega4809 users to get started with the ATmega4809 peripherals
right away and to get an understanding of how to integrate the device into their own design.
ATmega4809 Xplained Pro
Introduction
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 4

Figure 1-1. ATmega4809 Xplained Pro Evaluation Kit Overview
DEBUG USB
POWER HEADER
EXTENSION 1 HEADER
EXTENSION 2 HEADER
EXTENSION 3 HEADER
ATmega4809
RESET BUTTON
CURRENT MEASUREMENT
HEADER
SW0 USER BUTTON
USER LED0
mikroBUS™ socket
AVR® DEBUG
FOR EXTERNAL
DEBUGGER
UDFN8
CryptoAuthentication™
DEVICE FOOTPRINT
32.768 kHz Crystal
TARGET VOLTAGE
SELECT HEADER
Info: There is no IC mounted on the UDFN8 CryptoAuthentication footprint.
ATmega4809 Xplained Pro
Introduction
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 5

2. Getting Started
2.1 Xplained Pro Quick Start
Steps to start exploring the Xplained Pro platform:
1. Download and install Microchip Studio/MPLAB® X.
2. Launch Microchip Studio/MPLAB® X.
3. Connect the Debug USB port on the evaluation kit to the computer using a USB cable (Standard-A to Micro-B
or Micro-AB).
When the Xplained Pro MCU kit is connected to the computer for the first time, the operating system installs the
driver software automatically. This driver supports 32-bit and 64-bit versions of Microsoft® Windows® XP, Windows
Vista®, Windows 7, Windows 8, Windows 10, and Windows Server 2012.
When the Xplained Pro MCU board is powered, the power LED (green) glows, and Microchip Studio/MPLAB® X
automatically detects the specific Xplained Pro MCU and extension board(s) that are connected. The landing page of
the kit in the Microchip Studio has an option to launch the Atmel Software Framework (ASF) and the Atmel START
example application codes for the kit. The ATmega4809 device is programmed and debugged by the on-board
embedded debugger and, therefore, no external programmer or debugger tool is required.
2.2 Design Documentation and Relevant Links
The following list contains links to the most relevant documents and software for the ATmega4809 Xplained Pro.
•Xplained Products - Xplained Evaluation Kits are a series of easy-to-use evaluation kits for Microchip
microcontrollers and other Microchip products.
– Xplained Nano - used for low pin count devices and provides a minimalistic solution with access to all I/O
pins of the target microcontroller.
– Xplained Mini - used for medium pin count devices and adds Arduino Uno compatible header footprint and
a prototyping area.
– Xplained Pro - used for medium-to-high pin count devices that feature advanced debugging and
standardized extensions for peripheral functions.
Note: All the above kits have on-board programmers/debuggers, which create a set of low-cost boards for
evaluation and demonstration of features and capabilities of different Microchip products.
•Microchip Studio - Free IDE for the development of C/C++ and assembler code for microcontrollers.
•EDBG User Guide - User guide containing more information about the on-board Embedded Debugger.
•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.
•Atmel START - Atmel START is an online tool that hosts code examples, helps the user to select and configure
software components, and tailors the embedded application in a usable and optimized manner.
•ATmega4809 Xplained Pro website - Kit information, latest user guide and design documentation.
•ATmega4809 Xplained Pro on Microchip Direct - Purchase this kit on Microchip Direct.
•CryptoAuthentication Devices - Microchip CryptoAuthentication™ devices offer hardware-based ultra secure
key storage to ensure that a product with the consumables it uses, firmware it runs, accessories that supports it,
and the network nodes it connects to are not cloned, counterfeited, or tampered with.
ATmega4809 Xplained Pro
Getting Started
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 6

3. Xplained Pro
Xplained Pro is an evaluation platform containing a series of microcontroller boards (evaluation kits) and extension
boards. Microchip Studio/MPLAB® X is used to program and debug the microcontrollers on these boards. Microchip
Studio includes Advanced Software Framework (ASF) and Atmel START which has drivers, demo code, and Data
Visualizer that supports data streaming and advanced debugging. Xplained Pro evaluation kits can be connected to a
wide range of Xplained Pro extension boards through standardized headers and connectors. Xplained Pro extension
boards have identification (ID) chips to uniquely identify which boards are connected to the Xplained Pro evaluation
kits.
3.1 Embedded Debugger
The ATmega4809 Xplained Pro contains an Embedded Debugger (EDBG) for on-board debugging. The EDBG is a
USB composite device with the following interfaces:
• Debugger
• Virtual COM Port (CDC)
• Data Gateway Interface (DGI)
The EDBG can program and debug the ATmega4809 with the help of Microchip Studio/MPLAB® X. The UPDI
interface is connected between the EDBG and the ATmega4809 on the ATmega4809 Xplained Pro.
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. It offers variable baud rate, parity, and stop bit settings. The settings
on the ATmega4809 must match the settings given in the terminal software.
Info: The Virtual COM Port in the EDBG requires the terminal software to set the Data Terminal Ready
(DTR) signal to enable the UART pins connected to the ATmega4809. If the DTR signal is not enabled, the
UART pins on the EDBG are kept in tri-state (high-Z) to render the COM Port not usable. The DTR signal
is automatically set by terminal software, but it may have to be manually enabled in the terminal.
The DGI consists of several physical interfaces for bidirectional communication with the host computer.
Communication over the interfaces is bidirectional. It can be used to send event values and data from the
ATmega4809. Traffic over the interfaces can be timestamped by the EDBG for more accurate tracking of events, but
timestamping reduces the maximal data throughput. The Studio Data Visualizer is used to send and receive data
through DGI.
The EDBG controls two LEDs on the ATmega4809 Xplained Pro: a power LED and a status LED. The following table
provides details on how the LEDs are controlled in different operation modes.
Table 3-1. EDBG LED Control
Mode Power LED Status LED
Normal mode The power LED is ON when power is
applied to the board.
Activity indicator, the LED flashes
when any communication happens to
the EDBG.
Bootloader mode (idle) The power LED and the status LED blink simultaneously.
Bootloader mode (firmware upgrade) The power LED and the status LED blink in an alternating pattern.
For additional information on the EDBG, see the EDBG User Guide.
3.2 Hardware Identification System
All Xplained Pro extension boards come with an identification chip (ATSHA204A CryptoAuthentication™ chip) to
uniquely identify the boards that are connected to the Xplained Pro Evaluation Kit. This chip contains information that
ATmega4809 Xplained Pro
Xplained Pro
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 7

identifies the extension with its name and some extra data. When an Xplained Pro extension is connected to an
Xplained Pro Evaluation Kit, the information is read and sent to the Microchip Studio/MPLAB® X. The following table
shows the data fields stored in the ID chip with example content.
Table 3-2. Xplained Pro ID Chip Content
Data Field Data Type Example Content
Manufacturer ASCII string Microchip'\0'
Product name ASCII string Segment LCD1 Xplained Pro'\0'
Product revision ASCII string 02'\0'
Product serial number ASCII string 1774020200000010’\0’
Minimum voltage [mV] uint16_t 3000
Maximum voltage [mV] uint16_t 3600
Maximum current [mA] uint16_t 30
3.3 Power Sources
The ATmega4809 Xplained Pro kit can be powered by several power sources, as listed in the following table.
Table 3-3. Power Sources for ATmega4809 Xplained Pro
Power Source Voltage Requirements Current Requirements Connector Marking
External power 5V ±2% (±100 mV) for USB
host operation. 4.3V to
5.5V if a USB host
operation is not required.
The recommended value
for the maximum current is
2A
PWR
Embedded debugger USB 4.4V to 5.25V (according to
USB specification)
500 mA (according to USB
specification)
DEBUG USB
The kit automatically detects the available power sources and chooses which to use according to the following
priority:
1. External power
2. Embedded debugger USB
Info: External power is required when 500 mA from a USB connector is not enough to power the board
with possible extension boards.
3.4 Xplained Pro Headers and Connectors
3.4.1 Xplained Pro Standard Extension Header
All Xplained Pro kits have many dual-row, 20-pin, 100 mil extension headers. The Xplained Pro MCU boards have
male headers, while the Xplained Pro extensions have their female counterparts. The following table provides the pin
description of all the connected pins.
ATmega4809 Xplained Pro
Xplained Pro
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 8

Info: Not all pins are always connected to all extension headers.
The extension headers can be used to connect a variety of Xplained Pro extensions to Xplained Pro MCU boards or
to access the pins of the target microcontroller on the Xplained Pro boards.
Table 3-4. Xplained Pro Standard Extension Header
Pin Number Pin Name Description
1 ID Pin to communicate with the ID chip on an extension board.
2 GND Ground.
3 ADC(+) Analog-to-Digital Converter; alternatively, a pin for the positive terminal of a
differential ADC.
4 ADC(-) Analog-to-Digital Converter; alternatively, a pin for the negative terminal of a
differential ADC.
5 GPIO1 General purpose I/O pin.
6 GPIO2 General purpose I/O pin.
7 PWM(+) Pulse-Width Modulation; alternatively, a pin for the positive part of a
differential PWM.
8 PWM(-) Pulse-Width Modulation; alternatively, a pin for the negative part of a
differential PWM.
9 IRQ/GPIO Interrupt request pin and/or general purpose I/O pin.
10 SPI_SS_B/GPIO Client select pin for Serial Peripheral Interface (SPI) and/or general purpose
I/O pin.
11 I2C_SDA Data pin for I2C interface. Always connected, bus type.
12 I2C_SCL Clock pin for I2C interface. Always connected, bus type.
13 UART_RX Receiver pin of target device UART.
14 UART_TX Transmitter pin of target device UART.
15 SPI_SS_A Client select for SPI. This pin should preferably not be connected to
anything else.
16 SPI_MOSI SPI host out, client in pin. Always connected, bus type.
17 SPI_MISO SPI host in, client out pin. Always connected, bus type.
18 SPI_SCK SPI clock pin. Always connected, bus type.
19 GND Ground pin for extension boards.
20 VCC Power pin for extension boards.
3.4.2 Xplained Pro Power Header
The power header can be used to connect external power to the ATmega4809 Xplained Pro kit. The kit automatically
detects and switches to an external power source, if supplied. The power header can also be used to supply power to
external peripherals or extension boards. Ensure that the total current does not exceed the recommended current
limit of the on-board regulator when using the 3.3V pin.
ATmega4809 Xplained Pro
Xplained Pro
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 9

Table 3-5. Xplained Pro Power Header
Pin Number Pin Name Description
1 VEXT_P5V0 External 5V input pin
2 GND Ground pin
3 VCC_P5V0 Unregulated 5V pin (an output, derived from one of the input
sources)
4 VCC_P3V3 Regulated 3.3V pin (an output, used as the main power
supply for the kit)
ATmega4809 Xplained Pro
Xplained Pro
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 10

4. Hardware User Guide
The following sections describe the implementation of the relevant connectors, headers, and peripherals on
ATmega4809 Xplained Pro, and their connection to ATmega4809. The tables of connections in the sections also
describe which signals are shared between the connectors, headers, and peripherals. The figure below shows all
available headers, connectors, jumpers, and peripherals on ATmega4809 Xplained Pro.
Figure 4-1. ATmega4809 Xplained Pro Connector Overview
4.1 Power Distribution
ATmega4809 Xplained Pro has two power sources as described in 3.3 Power Sources. The block diagram below
shows the power supply circuitry on the board. The kit can be powered by the EDBG USB and an external 5.0V
source. The kit will automatically select which source to draw power from. ATmega4809 can be powered by 3.3V
ATmega4809 Xplained Pro
Hardware User Guide
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 11

(regulated) or 5.0V (USB/external voltage). The voltage is selectable using a jumper on the power selection header
J105.
An on-board power switch is used to turn power to the ATmega4809 ON and OFF. This power switch is controlled by
the EDBG. When the kit is powered up, the EDBG reads the ID chip information from all connected Xplained Pro
extension boards and checks that they are compatible with the voltage selected by the power selection header J105.
If the selected voltage is within the connected extensions ranges, the switch will open. If not, the EDBG power LED
will blink rapidly and the switch will stay closed resulting in no power provided to ATmega4809, the on-board
peripherals, and the connectors.
CAUTION
As ATmega4809 Xplained Pro can be powered by 5.0V, care must be taken not to connect any Xplained
Pro extensions that do not support this voltage, doing so may result in permanent damage. Check the
respective extension kit's user guide to see which voltages are acceptable.
Info: The EDBG reads the ID information from Xplained Pro extensions and controls the power switch
when the kit is powered up. This mechanism does not check hot-plugging of extension boards.
Figure 4-2. Power Supply Block Diagram
VCC_P5V0
External 5V input
EDBG
ATmega4809
Regulator 3.3V
Power Select
(Jumper)
EDBG USB
Auto MUX
VCC_P3V3
Peripherals
VCC_TARGET
VCC_MCU
Power Switch Jumper
TARGET_VCC_ ENABLE
Regulator 3.3V
Power source
Power switch/
Jumper/Header
Power converter
Power consumer
VCC_EDBG
J105
mikroBUS™ Socket
JP J P
P S P S
J207 J204
HD HD
J103
TARGET_VCC_ ENABLE
J209 J208
4.2 Connectors
4.2.1 Xplained Pro Standard Extension Headers
The Xplained Pro extension headers EXT1, EXT2, and EXT3 offer access to the I/O of the microcontroller to expand
the board, for example, by connecting extensions to the board. These headers are based on the standard Xplained
Pro extension header specification. The connections are shown in the table below. The headers have a pitch of 2.54
mm.
ATmega4809 Xplained Pro
Hardware User Guide
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 12

Table 4-1. Extension Header EXT1
EXT1 Pin ATmega4809 Pin Function Shared Functionality
1 [ID] — — Communication line to the ID
chip on an extension board
2 [GND] — — Ground
3 [ADC(+)] PD2 ADC0 AIN2 —
4 [ADC(-)] PD3 ADC0 AIN3 —
5 [GPIO1] PA2 GPIO (USART0 XCK) —
6 [GPIO2] PA3 GPIO (USART0 XDIR) —
7 [PWM(+)] PC4 TCA0 WO4 —
8 [PWM(-)] PC5 TCA0 WO5 —
9 [IRQ/GPIO] PC6 GPIO —
10 [SPI_SS_B/GPIO] PC7 GPIO —
11 [TWI_SDA] PC2 TWI0 SDA EXT2, EXT3, mikroBUS™,
CryptoAuthentication™ footprint,
EDBG DGI
12 [TWI_SCL] PC3 TWI0 SCL EXT2, EXT3, mikroBUS™,
CryptoAuthentication™ footprint,
EDBG DGI
13 [USART_RX] PA1 USART0 RxD —
14 [USART_TX] PA0 USART0 TxD —
15 [SPI_SS_A] PA7 SPI0 SS —
16 [SPI_MOSI] PA4 SPI0 MOSI EXT2, EXT3, mikroBUS™, EDBG
DGI
17 [SPI_MISO] PA5 SPI0 MISO EXT2, EXT3, mikroBUS™, EDBG
DGI
18 [SPI_SCK] PA6 SPI0 SCK EXT2, EXT3, mikroBUS™, EDBG
DGI
19 [GND] — — Ground
20 [VCC] — — Power for extension board
Table 4-2. Extension Header EXT2
EXT2 Pin ATmega4809 Pin Function Shared Functionality
1 [ID] — — Communication line to the ID
chip on an extension board
2 [GND] — — Ground
3 [ADC(+)] PD4 ADC0 AIN4 —
4 [ADC(-)] PD5 ADC0 AIN5 —
5 [GPIO1] PE0 GPIO —
6 [GPIO2] PF6 GPIO/RESET SW1, DEBUG, EDBG
ATmega4809 Xplained Pro
Hardware User Guide
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...........continued
EXT2 Pin ATmega4809 Pin Function Shared Functionality
7 [PWM(+)] PB4 TCA0 WO4 DGI GPIO2
8 [PWM(-)] PB5 TCA0 WO5 DGI GPIO3, LED0
9 [IRQ/GPIO] PB2 GPIO DGI GPIO0, SW0
10 [SPI_SS_B/GPIO] PB3 GPIO DGI GPIO1
11 [TWI_SDA] PC2 TWI0 SDA EXT1, EXT3, mikroBUS™,
CryptoAuthentication™ footprint,
EDBG DGI
12 [TWI_SCL] PC3 TWI0 SCL EXT1, EXT3, mikroBUS™,
CryptoAuthentication™ footprint,
EDBG DGI
13 [USART_RX] PC1 USART1 RxD EDBG CDC
14 [USART_TX] PC0 USART1 TxD EDBG CDC
15 [SPI_SS_A] PE1 GPIO —
16 [SPI_MOSI] PA4 SPI0 MOSI EXT1, EXT3, mikroBUS™, EDBG
DGI
17 [SPI_MISO] PA5 SPI0 MISO EXT1, EXT3, mikroBUS™, EDBG
DGI
18 [SPI_SCK] PA6 SPI0 SCK EXT1, EXT3, mikroBUS™, EDBG
DGI
19 [GND] — — Ground
20 [VCC] — — Power for extension board
Table 4-3. Extension Header EXT3
EXT3 Pin ATmega4809 Pin Function Shared Functionality
1 [ID] — — Communication line to the ID
chip on an extension board
2 [GND] — — Ground
3 [ADC(+)] PD6 ADC0 AIN6 mikroBUS™
4 [ADC(-)] PD7 ADC0 AIN7 —
5 [GPIO1] PD0 GPIO mikroBUS™
6 [GPIO2] PD1 GPIO mikroBUS™
7 [PWM(+)] PF4 TCB0 WO (TCA0 WO4)mikroBUS™
8 [PWM(-)] PF5 TCB1 WO (TCA0 WO5)mikroBUS™
9 [IRQ/GPIO] PE2 GPIO mikroBUS™
10 [SPI_SS_B/GPIO] PE3 GPIO —
11 [TWI_SDA] PC2 TWI0 SDA EXT1, EXT2, mikroBUS™,
CryptoAuthentication™ footprint,
EDBG DGI
ATmega4809 Xplained Pro
Hardware User Guide
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 14

...........continued
EXT3 Pin ATmega4809 Pin Function Shared Functionality
12 [TWI_SCL] PC3 TWI0 SCL EXT1, EXT2, mikroBUS™,
CryptoAuthentication™ footprint,
EDBG DGI
13 [USART_RX] PB1 USART3 RxD mikroBUS™
14 [USART_TX] PB0 USART3 TxD mikroBUS™
15 [SPI_SS_A] PF2 GPIO mikroBUS™
16 [SPI_MOSI] PA4 SPI0 MOSI EXT1, EXT2, mikroBUS™, EDBG
DGI
17 [SPI_MISO] PA5 SPI0 MISO EXT1, EXT2, mikroBUS™, EDBG
DGI
18 [SPI_SCK] PA6 SPI0 SCK EXT1, EXT2, mikroBUS™, EDBG
DGI
19 [GND] — — Ground
20 [VCC] — — Power for extension board
4.2.2 mikroBUS™ Socket
ATmega4809 Xplained Pro has one mikroBUS socket that can be used with MikroElektronika click modules. The
table below shows the signals connected to the mikroBUS socket.
Table 4-4. mikroBUS™ Socket
Function ATmega4809 Pin mikroBUS™ATmega4809 Pin Function
ADC0 AIN6 PD6 AN PWM PF4 TCB0 WO (TCA0 WO4)
GPIO PD0 RST INT PE2 GPIO
GPIO PF2 CS RX PB1 USART3 RxD
SPI0 SCK PA6 SCK TX PB0 USART3 TxD
SPI0 MISO PA5 MISO SCL PC3 TWI0 SCL
SPI0 MOSI PA4 MOSI SDA PC2 TWI0 SDA
— — 3.3V 5.0V — —
— — GND GND — —
Info: All signals on the mikroBUS socket are shared with Xplained Pro extension header EXT3. Make
sure that the connected mikroBUS add-on board and Xplained Pro extension does not use the same
signals if both connectors are used at the same time.
Attention: 3.3V and 5.0V are connected directly to the mikroBUS socket. It is important to make sure the
ATmega4809 operates at the same voltage as the connected mikroBUS socket. The operating voltage for
the ATmega4809 is selected with the power selection header J105.
Related Links
4.1 Power Distribution
ATmega4809 Xplained Pro
Hardware User Guide
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 15

4.2.3 AVR® Debugger Connector
ATmega4809 Xplained Pro has a 10-pin 50-mil AVR Debug Connector (J202) with UPDI that can be used to attach
external debuggers to the ATmega4809. Microchip debugging tools like the Atmel-ICE and Power Debugger can
connect directly to this connector.
Table 4-5. AVR® 10-Pin Debugger Connector
AVR® 10-Pin Debugger
Connector Pin
Pin/Net Function Shared Functionality
1 [TCK] — — —
2 [GND] GND Ground —
3 [TDO/UPDI] UPDI UPDI programming/debug EDBG
4 [VTG] VCC_TARGET ATmega4809 voltage —
5 [TMS] — — —
6 [nSRST] PF6 ATmega4809 reset signal SW1, EXT1, EDBG
7 [NC] — — —
8 [nTRST] — — —
9 [TDI] — — —
10 [GND] GND Ground —
Info: PF6 (RESET) is usually not used by external debuggers as the ATmega4809 can be reset through
the UPDI interface. If the debugger requires the use of the RESET, pin PF6 has to be configured as
RESET with a fuse in the ATmega4809.
4.3 Peripherals
4.3.1 Crystals
ATmega4809 Xplained Pro has a 32.768 kHz crystal that can be used as clock source for the ATmega4809 device.
There are cut-straps located close to the crystals that can be used to measure the oscillator safety factor. This is
done by cutting the strap and adding a resistor across the strap. More information about oscillator allowance and
safety factor is available in the AVR4100 application note.
There is a 7 pF, 32.768 kHz crystal in a 3.2 mm by 1.5 mm package mounted on ATmega4809 Xplained Pro.
Table 4-6. External 32.768 kHz Crystal
ATmega4809 Pin Function
PF0 XIN32
PF1 XOUT32
Related Links
2.2 Design Documentation and Relevant Links
4.3.2 Mechanical Buttons
ATmega4809 Xplained Pro has two mechanical buttons. Both buttons are connected to I/O-pins on the ATmega4809
and can be used as general purpose buttons in the application. When a button is pressed, it will drive the I/O line to
GND.
ATmega4809 Xplained Pro
Hardware User Guide
© 2020 Microchip Technology Inc. User Guide DS50002716C-page 16

Button SW1 can also be used as a reset button if PF6 is configured as the RESET pin in the ATmega4809. PF6 is
configured as a RESET pin by writing fuses. For more information, see the ATmega4809 data sheet.
Info: There is no pull-up resistor connected to the generic user button SW0. Remember to enable the
internal pull-up in the ATmega4809 to use the button. There is an external pull-up resistor connected to
SW1 connected to PF6.
Table 4-7. Mechanical Buttons
ATmega4809 Pin Silkscreen Text Shared Functionality
PB2 SW0 EXT2, DGI GPIO0
PF6 SW1/RESET EXT2, DEBUG, EDBG
4.3.3 LED
One yellow LED available on the ATmega4809 Xplained Pro board can be turned ON and OFF. Drive the connected
I/O line to GND to activate the LED.
Table 4-8. LED Connection
ATmega4809 Pin Function Shared Functionality
PB5 Yellow LED0 EXT2, DGI GPIO3
4.3.4 Footprint for CryptoAuthentication™ Devices
ATmega4809 Xplained Pro has one UDFN8 footprint for Microchip I2C CryptoAuthentication devices where several
models can be soldered on. The table below shows all the connections between the UDFN8 footprint and the
ATmega4809.
Info: ATSHA204A, ATAES132A, ATECC608A, and ATECC508A are examples of devices that can be
soldered onto the UDFN8 footprint.
Info: The footprint is connected to I2C pins on the ATmega4809.
Table 4-9. UDFN8 Footprint Connections
UDFN8 Footprint Pin ATmega4809 Pin Function Shared Functionality
1 [NC] — — —
2 [NC] — — —
3 [NC] — — —
4 [GND] — GND —
5 [SDA] PC2 TWI0 SDA EXT1, EXT2, EXT3, mikroBUS™, EDBG DGI
6 [SCL] PC3 TWI0 SCL EXT1, EXT2, EXT3, mikroBUS™, EDBG DGI
7 [NC] — —
8 [VCC] — VCC_TARGET —
9 [PAD] — GND —
ATmega4809 Xplained Pro
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© 2020 Microchip Technology Inc. User Guide DS50002716C-page 17

4.4 Embedded Debugger Implementation
ATmega4809 Xplained Pro contains an Embedded Debugger (EDBG) that can be used to program and debug the
ATmega4809 using the UPDI interface. The Embedded Debugger also includes a Virtual Com port interface over
UART, a Data Gateway Interface over SPI, and I2C, and it includes four of the ATmega4809 GPIOs. Microchip Studio
and MPLAB® X can be used as a front end for the Embedded Debugger.
4.4.1 UPDI
The UPDI interface uses one pin to communicate with the target. For further information on how to use the
programming and debugging capabilities of the EDBG, see 3.1 Embedded Debugger.
Table 4-10. UPDI Connections
ATmega4809 Pin Function Shared Functionality
UPDI UPDI programming/debugging DEBUG
PF6 RESET SW1, EXT1, DEBUG
Info: PF6 (RESET) is usually not used by the EDBG as the ATmega4809 can be reset through the UPDI
interface.
4.4.2 Virtual COM Port
The Embedded Debugger acts as a Virtual Com Port gateway by using one of the ATmega4809 UARTs. For further
information on how to use the Virtual COM port, see 3.1 Embedded Debugger.
Table 4-11. Virtual COM Port Connections
ATmega4809 Pin Function Shared Functionality
PC0 USART1 TxD (ATmega4809 TX line) EXT2
PC1 USART1 RxD (ATmega4809 RX line) EXT2
4.4.3 Data Gateway Interface
The Embedded Debugger features a Data Gateway Interface (DGI) by using either an SPI or I2C. The DGI can be
used to send a variety of data from the ATmega4809 to the host PC. For further information on how to use the DGI
interface, see Studio Data Visualizer and the EDBG User Guide.
Table 4-12. DGI Interface Connections when using SPI
ATmega4809 Pin Function Shared Functionality
PF3 GPIO SPI SS (Client select) (ATmega4809 is
Host)
—
PA4 SPI0 MOSI (Host Out, Client In) EXT1, EXT2, EXT3, mikroBUS™
PA5 SPI0 MISO (Host In, Client Out) EXT1, EXT2, EXT3, mikroBUS™
PA6 SPI0 SCK (Clock Out) EXT1, EXT2, EXT3, mikroBUS™
Table 4-13. DGI Interface Connections when using I2C
ATmega4809 Pin Function Shared Functionality
PC2 TWI0 SDA EXT1, EXT2, EXT3, mikroBUS™,
CryptoAuthentication™ footprint
ATmega4809 Xplained Pro
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...........continued
ATmega4809 Pin Function Shared Functionality
PC3 TWI0 SCL EXT1, EXT2, EXT3, mikroBUS™,
CryptoAuthentication™ footprint
Four GPIO lines are connected to the Embedded Debugger. The EDBG can monitor these lines and time stamp pin
value changes, which make it possible to accurately timestamp events in the ATmega4809 application code. For
further information on how to configure and use the GPIO monitoring features, see Studio Data Visualizer and the
EDBG User Guide.
Table 4-14. GPIO Lines Connected to the EDBG
ATmega4809 Pin Function Shared Functionality
PB2 GPIO0 EXT2, SW0
PB3 GPIO1 EXT2
PB4 GPIO2 EXT2
PB5 GPIO3 EXT2, LED0
4.5 Kit Modifications
ATmega4809 Xplained Pro has several components that can be used to disconnect I/O pins of the ATmega4809 from
connectors and on-board ICs, and to disconnect power signals.
The table and figure below show components to modify connections to the EDBG and power supplies.
Table 4-15. Resistors
Designato
r
Value From To Comment
J106 Cut-strap J100 pin 4 VCC_TARGET Power header VCC target disconnect
J204 Cut-strap Power supply mikroBUS™ 5V0 Cut to remove power from the
mikroBUS™ header
J207 Cut-strap Power supply mikroBUS™ 3V3 Cut to remove power from the
mikroBUS™ header
F100 PTC fuse 5V input (USB and
External)
VCC_P5V0 All external 5V power, EDBG USB
and external 5V on J100 pin 1
R108 0Ω U100 OUT VCC_EDBG_P3V3 EDBG power supply
R504 0Ω EDBG DGI I2C SDA PC2 TWI0 SDA EDBG DGI I2C interface
R505 0Ω EDBG DGI I2C SCL PC3 TWI0 SCL
R509 0Ω EDBG TARGET RESET PF6 ATmega4809 RESET
R510 0Ω EDBG UPDI UPDI UPDI Programming/Debugging
signal
R514 330Ω EDBG DGI GPIO0 PB2 EDBG DGI GPIO interface
R515 330Ω EDBG DGI GPIO1 PB3
R516 330Ω EDBG DGI GPIO2 PB4
R517 330Ω EDBG DGI GPIO3 PB5
ATmega4809 Xplained Pro
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...........continued
Designato
r
Value From To Comment
R520 0Ω EDBG DGI SPI SS PF3 GPIO EDBG DGI SPI interface
R521 0Ω EDBG DGI SPI SCK PA6 SPI0 SCK
R522 0Ω EDBG DGI SPI MOSI PA4 SPI0 MOSI
R523 330Ω EDBG DGI SPI MISO PA5 SPI0 MISO
R526 330Ω EDBG CDC UART TX PC1 USART1 RxD EDBG CDC interface
R527 0Ω EDBG CDC UART RX PC0 USART1 TxD
ATmega4809 Xplained Pro
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