The LAUNCHXL-F28027 has a USB to UART adapter built in. This makes it easy to print debug
information back to the host PC even in isolated environments. However, in some cases the user may
wish to connect the Piccolo SCI peripheral (C2000 UART peripheral) to a BoosterPack or other hardware
via the header pins. If the SCI pins are connected to both the header pins, the XDS100 UART channel
contention would exist and the pins would not be driven to the correct voltage levels. To solve this issue
we have included a switch to allow the user to disconnect the Piccolo serial pins from the XDS100 UART
connection. When S4 is in the up position, the Piccolo device's SCI is connected to the XDS100 and you
are able to receive and send serial information from or to the board. When S4 is in the down position, the
Piccolo device's SCI is disconnected from the XDS100 and BoosterPacks, which use serial
communication, and can communicate with the Piccolo device.