One of the FADEC functions is the thrust reverser control.
On the other hand ,the aircraft supplies the FADEC during 5 minutes after the acft. is energized, and when the IGN/START is selected and below 12%N2. Above 12%N2 the FADEC is self powered. The acft. will supply the FADEC again when the MASTER SWITCH is off and below 12%N2, for 5 minutes.
I may be wrong, but you´re not going to use the reverser, anyway.