Uart And Usb Connections; Reset Button - Silicon Laboratories BRD8045A User Manual

3.2.1 UART and USB connections

As the BRD8045x Adapter Board for Co-Processor Radio Boards comes from the factory, the UART data lines are mapped to a particu-
lar UART port of the SiWx917 Wi-Fi Co-processor, supporting ISP mode. A slide switch allow users to connect this port either to the
host, for remote programming
terminal.
None of the orderable variants support UART connections with other EFR32 devices, however shunt resistors are provided to remap
the UART port in hardware, so that the UART can be repurposed for EFR32 devices or other Systems on Chip of the SiWx917 device
family. Users who intend to modify the hardware to remap the UART data lines can find schematic and assembly drawings at
labs.com. Both System on Chip and Co-processor UART data lines are always available on four break out pads, divided in two clusters
by a ground (GND) pad in the middle, respectively BO104-BO105 (RX/TX SoC) and BO102-BO103 (RX/TX NCP or RCP).
Summarized, the Adapter Board for Co-Processors Radio Boards allow the user to switch between the following three modes:
• USB – This is the factory default mode wherein UART peripheral is connected to the UART-USB bridge.
• NC – This mode allows the user to disconnect the UART data lines completely. In this mode, we can still interface with an external
UART device by means of break out pads.
• HOST – This mode enables the co-processor board to connect to the host's UART peripheral.
USB Type-C
Connector
Raspberry Pi
Connector
Expansion
Header
Shield
Connector
Note: 1. Remote ISP line is only with BRD8045B and BRD8045C host interfaces.

3.2.2 Reset Button

The RESET button can be used to reset the target device on the Radio Board (active low).
When connecting an STM32 Nucleo-64 board to the BRD8045C Adapter Board, the on-board reset circuit resets both the host and
device chip at the same time when the button is pressed, but it still allows the host resetting the device remotely without resetting itself.
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, or to the on-board UART-USB bridge, to connect a PC and load the Co-processor firmaware using a
USB-to-UART
Converter
GPIO14
GPIO15
EXP12
EXP14
D0
D1
Figure 3.2. UART Slide Switch
UG569: Adapter Board for Co-Processor Radio Boards User's Guide
USB NC HOST
Hardware Overview
si-
Co-Processor
Radio Board
Rev. 1.0 | 9