13 Appendix

13.1 Glossary

Table 13-1. Glossary of Terms
Term	Description
Debugger	The physical hardware device used to interface between an embedded system and a host computer
Embedded debugger	A debugger device that is permanently mounted on a larger embedded system
Kit	A printed circuit board assembly containing both a target device and an embedded debugger, typically used for firmware development before custom hardware is available
CNANO	Curiosity Nano
EDBG	Microchip Embedded Debugger, which is used on various development boards
nEDBG	The Nano variant of the EDBG, also known as PKOB nano and the Nano Debugger
PKOB	Microchip PICkit® on-Board debugger, which is used on various development boards
CMSIS-DAP	The standardized, USB-based interface that allows a hardware debugger to provide a host computer with access to the CoreSight Debug Access Port (DAP) of Arm Cortex processors
SWD	Serial Wire Debug - a two-wire programming and debugging protocol developed by Arm
UPDI	Unified Program and Debug Interface - a single-wire progrmaming and debugging protocol developed by Microchip, used on AVR devices
ICSP	In-Circuit Serial Programming - a two-wire programming and debugging interface used on PIC16, PIC18, PIC24 and dsPIC devices (using different protocols)
CDC	Communication Device Class, or Virtual Serial Port, typically used for printf() debugging
MSC	Mass Storage Class - a USB protocol for implementing removable storage, also known as MSD (Mass Storage Device)
DGI	Data Gateway Interface - a data-streaming mechanism developed by Microchip that allows timestamped data to be streamed from an embedded debugger to a host computer for visualization

13.2 Target Device Interfaces

The Nano Debugger supports a variety of target device interfaces through a standardised set of pins.

Table 13-2. Target Device Interface Connections
Signal	Arm/SWD	AVR UPDI	ICSP	Implementation
DBG0	Serial Wire Data SWDIO	UPDI	PGD	Bi-directional, direct or level-shifted
DBG1	Serial Wire Clock SWCLK	-	PGC	Bi-directional, direct or level-shifted
DBG2	Serial Wire Output SWO	-	-	Bi-directional, direct or level-shifted
DBG3	/RESET	/RESET	MCLR	Open-drain connection

: DBG2 is used for DGI-GPIO. For AVR boards, DBG1 is also available for DGI-GPIO.

13.3 Auxilliary Interfaces

Virtual Serial Port/CDC

The Nano Debugger features a Virtual Serial Port (CDC), which is always included during USB enumeration.

Connect the RX and TX lines according to the guidance provided in the relevant schematic.

If you do not wish to use the Virtual Serial Port, leave the PA00 pin of the Nano Debugger unconnected and install a pull-up resistor between PA01 and the 3.3V supply rail.

Data Gateway Interface/DGI

The Nano Debugger features Data Gateway Interfaces (DGI), which are always included during USB enumeration. Depending on the number of signals required by the target debug interface and your specific needs, zero, one, or two DGI GPIO channels can be supported.

If you do not wish to use a DGI GPIO channel, leave it unconnected and ensure it is disabled in the configuration. Refer to the default configuration table to determine whether DGI GPIO is enabled by default.

13.4 Nano Debugger Configuration

13.4.1 Introduction

The Microchip Nano Debugger is versatile and can be used in a range of scenarios as described above. All implementations operate using a single, identical firmware binary image. The specific behavior for each scenario is determined by the "board configuration," while information about the device connected to the Nano Debugger on a development board is managed through its "device configuration."

Both the board configuration and the device configuration are defined in XML format but are stored in a dedicated section of flash memory within the Nano Debugger.

Board Configuration

All implementations that use the Nano Debugger must include a board configuration. Without a board configuration, the Nano Debugger will not function correctly.

The board configuration is stored in two separate locations within the Nano Debugger’s non-volatile memory:

The user-config is designed to be easily modified by the user.
The factory-config serves as a rollback backup, allowing a modified user-config to be restored to its original factory state.

The board configuration can be put in place in several ways:

The Nano Debugger firmware zip package includes several complete images, each containing a valid board configuration that corresponds to the board types described in this document. While the bootloader and application are identical across these images, the board configurations provide a suitable "default" state for each of the primary scenarios or use cases.
The pydebuggerconfig tool, available on pypi.org, can be used to:
- Write, replace, or upload an entirely new XML configuration file to a running Nano Debugger
- Modify the default board configuration on a running Nano Debugger

Device Configuration

The device configuration in the Nano Debugger provides information about the device that is permanently connected to the debugger. Its primary purpose is to enable drag-and-drop programming, which operates independently of an IDE. While the device configuration can be left empty (unprogrammed), it is recommended to program a null or dummy device configuration in cases where drag-and-drop programming is not supported (such as with Arm target devices) or when no target device is present (such as in a standalone debugger scenario).

The device configuration exists as a single instance and is not intended to be modified by the user.

The images included in the Nano Debugger firmware ZIP package contain the null device configuration.

The pydebuggerconfig tool, available on pypi.org, can be used to write or replace the device configuration on a running Nano Debugger.

13.4.2 Board Configuration Details

With the pydebuggerconfig tool, available on pypi.org, you can program a complete board configuration XML file or modify individual configuration fields as needed.

Many of the fields available in the board configuration are not intended to be modified, as they are either reserved for future use or intended specifically for Microchip kits.

Basic Configuaration Fields

The following fields can be modified by kit developers using the Nano Debugger. These basic fields are intended to personalize a kit or board, making it easily identifiable for users.

Table 13-3. Basic Configuration
Register	Description	What its for
DEVNAME	Device name. Maximum length: 32 ASCII characters.	Specify the exact device name here if a device is permanently mounted on the board. If the target device is not mounted on the board this field must be left blank.
KITNAME	Kit name. Maximum length: 60 ASCII characters.	Give your kit a nice name here
MNFRNAME	Manufacturer name. Maximum length: 60 ASCII characters.	Specify who you are as a vendor

Advanced Configuration Fields

The following fields can be modified by kit developers using the Nano Debugger when configuring more advanced boards.

Table 13-4. Advanced Configuration
Register	Description	What its for
SERNUM	USB serial number	A specific USB serial number can be set here. It is recommended to use exactly 20 upper-case alphanumeric characters and no spaces. Setting the "automatic serial number" bit will override this at enumeration-time, but the original value will remain in the configuration stored in Flash memory. Length: Always 20 characters.
REDIRECT	Redirect ID	See the tip below.
DATE	Manufacturing date	Optionally, specify the manufacturing date of the kit in the format YYYYMMDD
INSTANCE	Content revision	This is a simple version field and can be incremented for each change made to the configuration. Length: 8-bit.
TARGET_DEBUG_INTERFACES	Set of programing and debugging interfaces supported	Set the bits in this bitfield to indicate which physical interface(s) are supported in this implementation. Relevant bits are: bit 1: SWD for Arm devices bit 8: UPDI for AVR devices bit 10: SWO for Arm devices bit 11: ICSP for PIC and dsPIC devices Length: 32-bit.
TARGET_DEBUG_FEATURES	Set of programming and debugging features implemented	Set the bits in this bitfield to enable individual features: Relevant bits are: bit 0: SINGLE_DEVICE - set this bit if the device is permanently mounted to the board bit 1: PROG_ENABLED - set this bit to enable programming bit 2: DEBUG_ENABLED - set this bit to enable debugging bit 3: FUSE_CONFIG_PROTECTION - set this bit to enable protection of fuses/configuration bytes. A set of protection masks must be provided in the device configuration for this to work! bit 4: AUTO_SERIAL_NUMBER - set this bit to automatically generate a USB serial number Length: 8-bit.
DGI_INTERFACES	Set of DGI interfaces supported	Set the bits in this bitfield to indicate to the debugger which DGI interfaces are connected. Relevant bits are: bit 0: GPIO Length: 32-bit.
DGI_GPIO_MAP	Map of DGI GPIO channels	Set the bits in this bitfield to indicate to the debugger which DGI GPIO lines are connected. Relevant bits are: bit 0: DGI_GPIO0 bit 1: DGI_GPIO1 Length: 8-bit.
ANALOG_FEATURES	Analog features	Set the bits in this bitfield to indicate to the debugger which analog implementation is present on the board. Relevant bits are: bit 0: TVS - the debugger can control the target voltage bit 1: TVR - the debugger can measure the target voltage bit 2: LVC - level shifters are present between the debugger and the target Length: 32-bit.
VMIN	Minimum voltage	For adjustable-voltage boards, specify the minimum voltage in decivolts
VMAX	Maximum voltage	For adjustable-voltage boards, specify the maximum voltage in decivolts
VTG	Default voltage	For adjustable-voltage boards, specify the default voltage in decivolts
VREG	Voltage regulator	For adjustable-voltage boards, specify the voltage regulation circuit implemented. Values are: 0x00 - not adjustable 0x01 - adjustable regulator configuration 0x01 controlled by the Nano Debugger

Tip: The REDIRECT field is a four‑character string used to configure the KIT‑INFO.HTM link in the Curiosity Nano virtual disk drive implementation. This field can optionally be customized on a per-design basis (not per manufactured unit). To request a custom REDIRECT configuration, contact Microchip Support or email edbg@microchip.com.

Configuration Fields That Must not be Modified

These fields must remain unchanged when using the Nano Debugger.

Table 13-5. Do not Modify Configuration
Register(s)	Description	Mandatory Value
CONFIG_FORMAT_MAJOR CONFIG_FORMAT_MINOR CONFIG_FORMAT_BUILD	The version of the configuration specification being used. If new fields are added, this version is updated, and this document will be updated accordingly	(latest)
HARDWARE_MOD	Specify hardware modifications that affect the firmware	0x00
USB_ENUMERATION	USB enumeration	0x03
MSD_SETTINGS	Mass storage content settings	0x00
CLICK_ME_TYPE	Click-me type configuration	0xFF
ID_CHANNELS	Channels for extension identification	0x00
I2C_ADDR_0, I2C_ADDR_1	I²C address, alternative I²C address	0x00
LABS	Activate experimental firmware features	0x00
KEYx_TYPE, KEYx_LEN, KEYx	Key x type, length, value	0x00... 0x00

13.5 Nano Debugger Firmware Images

The Nano Debugger composite hex files are included in the PKOB Nano Support Tool Pack version 1.19 or newer, which can be downloaded from packs.download.microchip.com/.

The Tool Pack contains a ZIP file with a title starting with nedbg-composite, which contains:

The readme.md file contains additional technical information for using the Nano Debugger hex files
The versions.txt file contains versioning information about the contents of the ZIP file
nedbg_standalonedebugger_x.y.z.hex for Making a Standalone Debugger
nedbg_standalonedebuggerwithtargetsupply_x.y.z.hex for Making a Standalone Debugger with Target Supply
nedbg_adjustablevoltageboard_x.y.z.hex for Making an Adjustable-voltage Board
nedbg_3v3board_x.y.z.hex for Making a 3.3V Board
nedbg_fixedlvoltagelevelshiftedboard_x.y.z.hex for Making a Fixed-Voltage Level-Shifted Board

Select one of the hex files for use during manufacturing. For additional information, refer toImportant Considerations Before You Start

All hex files include the same bootloader and application but feature different default configurations. Any of these files can be reconfigured during manufacturing to meet your specific requirements.

13.6 Schematics

Figure 13-1. Standalone Nano Debugger

Figure 13-2. Fixed 3V3 Nano Debugger