To provide time-of-day timestamps on the local clock (either a RX SerDes
recovered clock or TX SerDes clock), the PTP/System Timer running on the DCMAC Subsystem local clock needs to be synchronized to the master
time-of-day timer running on the system timer clock ( ts_clk_N). The DCMAC Subsystem system timer can
be synchronized with a master timer in a number of methods. Each port has independent
internal free-running system_timer per RX and TX. For the
following description, the D variable must be
substituted with the desired TX and RX direction target and the N variable must be substituted by the target port number.