Laird Lyra S, Руководство пользователя

Страница: 11 / 17

https://www.lairdconnect.com/ 11
© Copyright 2022 Laird Connectivity
All Rights Reserved
Americas : +1-800-492-2320
Europe : +44-1628-858-940
Hong Kong : +852-2762-4823
For the Lyra S module the BOOT pin is on PA06 (pin18). On the Lyra dev board BTN0 (Button 0) is by default mapped to the
BOOT pin for easier utilisation.
The BOOT pin (PA06) is used to determine when execution of the bootloader is required. Upon reset, execution of the
bootloader begins. The state of the BOOT pin is read immediately upon start-up of the bootloader. If LOW (BTN0 pressed),
execution of the bootloader continues, facilitating firmware update via the UART. If the BOOT pin is HIGH (BTN0 not pressed),
the bootloader will stop execution and pass control to the main application firmware.
Please refer to respective DVK schematics and Serial DFU section of User Guide - Firmware Options and Upgrading - Lyra
Series for more information.
The Lyra S Development Kit contains a microcontroller separate from the Lyra S that provides the user with an on-board
J-Link debugger through the USB Micro-B port. This microcontroller is referred to as the "on-board debugger
” and is not
programmable by the user. When the USB cable is removed, the on-board debugger goes into a very low power shutoff mode
(EM4S), consuming around 80 nA typically (EFM32GG12 data sheet number).
In addition to providing code download and debug features, the on-board debugger also presents a virtual COM port for
general purpose application serial data transfer. The Packet Trace Interface (PTI) is also supported which offers
invaluable debug information about transmitted and received packets in wireless links.
The figure below shows the connections between the target Lyra S device and the on-board debugger. See Debugging for
more details on debugging.
Figure 5: Lyra S DVK Debugger Connections