The captured timestamp can optionally be provided
in-line with the received frame using the TEMAC existing AXI4-Stream interface – Receive Tri-Mode Ethernet MAC LogiCORE IP Product
Guide (PG051). Enable this mode of operation
through an AXI4-Lite configuration bit (see Table 1, bit 22).
When enabled, a 64-bit timestamp is passed to
the client immediately before the start of the frame reception (in place of the Preamble
field). This 64-bit value includes the lower 32-bits of the seconds field, plus the
entire nanoseconds field. See the previous figure.
When this in-line timestamp mode is not
enabled, the AXI4-Stream Interface - Receive is unchanged
from the current operation as described in the
Tri-Mode Ethernet MAC LogiCORE IP Product
Guide (PG051).
Figure 1. Timing Diagram of the In-Line Timestamp and Received Frame