Microchip Technology AVR-BLE, Hardware User'S Manual, Page: 12 / 30

3.1.3.3 Limitations 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.
3.1.3.4 Special 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.)
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.
3.1.4 Data Gateway Interface (DGI)
Data Gateway Interface (DGI) is a USB interface for transporting raw and time-stamped 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 AVR-BLE implementation includes logic analyzer
channels:
• Two debug GPIO channels (also known as DGI GPIO)
3.1.4.1 Debug 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.
Hardware User Guide
©
2020 Microchip Technology Inc.
User Guide
DS50002956A-page 12