The ingress logic does not parse the ingress packets to search for 1588 (PTP) frames. Instead, it takes a timestamp for every received frame and outputs this value to the user logic. The feature is always enabled, but the timestamp output can be ignored if you do not require this function.
Timestamps are filtered after the PCS decoder to retain only those timestamps corresponding to an Start of Packet (SoP). These 80-bit timestamps are output on the system side. The timestamp is valid during the SoP cycle and when ena_out = 1.