At the simplest level you can change whether an SDK project sends output via semihosting or UART by modifying the values of the defines SDK_DEBUGCONSOLE and SDK_DEBUGCONSOLE_UART. See the MCUXpresso IDE v10.1 User Guide, section 13.5.5, "Printf when using SDK", for more details.
But the easiest way to change UART / Semihosting is to select your project in the Project Explorer view, then go to
- QuickStart Panel -> Quick Settings -> SDK Debug Console
and select "Semihost console" or "UART console" as required. (See section 16.1, "Quick Settings" of the User Guide for more details).
Regards,
MCUXpresso IDE Support