TSE IEEE1588 feature

Hello!

I want to receive a timestamp for an incoming message. The documentation (Intel FPGA Triple-Speed Ethernet IP Core User Guide) says "In the receive datapath, the IEEE 1588v2 feature provides a timestamp for all receive

frames. The timestamp is aligned with the avalon_st_rx_startofpacket signal." What does it mean? Can I get the timestamp from avalon bus?