13.3.2.1.3 Software Reset
The software Reset makes it possible to issue a system Reset from software. The Reset is generated by writing a '1' to the Software Reset Enable bit (SWRE) in the Software Reset register (RSTCTRL.SWRR).
The Reset will take place immediately after the bit is written and the device will be kept in reset until the Reset sequence is completed. All logic is reset on software Reset, except UPDI and BOD configuration. All fuses are reloaded after the Reset is released.