It's a standard Daily Inspection item on some A330s. The requirement is to to trip the FMGEC CBs and reset after 20 minutes or down power the a/c for a similar time.
The memory can only hold something like 100 waypoints and this procedure ensures it is cleared.
There was an Airbus Service Bulletin out a few years ago.
I haven't seen it done on the 320 but that may be a different LRU manufacturer.