DP83848K: DAP thermal PAD connection

This is a design guide, layout guide question.

I can not find instruction about DAP thermal PAD in official datasheet for QFN40 package.

PAD has to be connected to GND, or could be floated?

Reference:

DP83848x PHYTER Mini / LS Single Port 10/100 MB/s Ethernet Transceiver datasheet (Rev. E) (ti.com)