31.3.2.2.2 UPDI Regular Disable

Any programming or debugging session that does not require any specific operation from the UPDI after disconnecting the programmer has to be terminated by writing the UPDI Disable (UPDIDIS) bit in the Control B (UPDI.CTRLB) register, upon which the UPDI will issue a System Reset and disable itself. The Reset will restore the CPU to the Run state, independent of the previous state. It will also lower the UPDI clock request to the system and reset any UPDI KEYs and settings.

If the disable operation is not performed, the UPDI and the oscillator’s request will remain enabled. This causes increased power consumption for the application.