Great question!!!!!
Great question....one that is misunderstood by many....too many.
Please refer to FCOM 3.04.27 P4, FCTM NO-160 P 3/12 (24 JUN 09), and
Airbus Flight Operations Briefing Note "Landing Techniques....Crosswind Landings" (April of 2006).
This will answer your question.
Fly safe,
PantLoad