Thanks A33Zab and Buzzbox. I am quite surprised that Direct Law, which is the most basic form of reversion (save the Mech Backup) still needs data from additional "boxes" like FCMC/FMGEC, or FAC in case of A320.
What happens if FCPC's/ELAC's stop receiving CG info? Do they revert to some default gains, or work on last received CG?