FWIW,
A Floor is triggered when the aircraft exceeds a pre-determined Angle of Attack. It has nothing to do with speed per se. The name gives it away.
I've had a quick look in the FCOM for the A thresholds for activation of A-floor but I can no longer find them so I think the information must have been removed at a recent revision.
The A-floor threshold depends on variant (318/319/320/321) and configuration (clean, F1/F2/F3/FFull).
IIRC, the threshold for a 320 is 9.5 Alpha in clean wing, 13 in F1, 14 in F2/3 and 15 in FFull or something like that.
It is possible to provoke A floor when the aircraft is still above VLS/AProt simply by snatching the sidestick back and so instaneously exceeding the A floor threshold. On releasing the sidestick the A FLOOR FMA will change to TOGA LK.
There is a very convincing demonstration of the efficacy of Normal Law protections and A FLOOR which can be done in the simulator by setting TL to idle, pulling hard back on the sidestick and simultaneously rolling to maximum achievable bank angle before letting the sidestick go. The simulator (aircraft) will gently spiral upwards at AProt, 30 deg AoB with ATHR in TOGA LK - safely away from terra firma.
HTH,
WS
Last edited by Wingswinger; 14th Nov 2011 at 07:01.