3.
Xplained Mini
Xplained Mini is an evaluation platform that provides a set of small boards with access to all microcontroller I/Os. The
platform consists of a series of low-pin-count Microcontroller (MCU) boards, which are integrated with Atmel Studio to
present relevant user guides, application notes, datasheets, and example code. The platform also features a Virtual
COM port for serial communication to a host PC.
3.1
Mini Embedded Debugger
The ATtiny817 Xplained Mini contains the Mini Embedded Debugger (mEDBG) for on-board programming and
debugging. The mEDBG is a composite USB device of two interfaces: A debugger and a virtual COM port.
Together with Atmel Studio, the mEDBG debugger interface can program and debug the ATtiny817. On ATtiny817
Xplained Mini, the UPDI interface is connected between the mEDBG and the ATtiny817.
The virtual COM port is connected to a UART on the ATtiny817 and provides an easy way to communicate with the
target application through the terminal software. It offers variable baud rate, parity, and Stop bit settings.
Note:
The settings on the ATtiny817 must match the settings given in the terminal software.
Info:
The virtual COM port in the mEDBG requires the terminal software to set the Data Terminal Ready
(DTR) signal to enable the UART pins connected to the ATtiny817. If the DTR signal is not enabled, the
UART pins on the mEDBG are kept in high-z (tri-state), rendering the COM port unusable. The DTR signal
is automatically set by some terminal software, but it may have to be manually enabled in the target
terminal.
The mEDBG controls one status LED on the ATtiny817 Xplained Mini. The table below shows how the LED is
controlled in different operation modes.
Table 3-1. mEDBG LED Control
Operation Mode
Status LED
Power-up
LED is briefly lit
Normal operation
LED is not lit
Programming
Activity indicator; the LED flashes when programming/
debugging with the mEDBG
3.1.1
Xplained Mini Clock Output
The mEDBG outputs its CPU clock on a pin.
The clock output can be used to feed the target device with a more accurate clock if this is needed for the application.
By default, this clock is disconnected from the target by a not mounted resistor.
To connect the external clock to the ATtiny817, a 0Ω resistor or strap has to be soldered in the footprint, as shown in
the figure below (R205).
ATtiny817 Xplained Mini
Xplained Mini
©
2019 Microchip Technology Inc.
User Guide
DS50002657B-page 6
