Receiver Skew Margin for LVDS Mode

Hi,

for calculation of RSKM (Cyclone 5 handbook, CV-52005 2020.07.24) one need a SW value:

SW—the period of time that the input data must be stable to ensure that data is successfully sampled by
the LVDS receiver. The SW is a device property and varies with device speed grade

Does anybody know where to find that value?

Jens