Altera 10-Gbps Ethernet MAC MegaCore Function - Manual (Page 166)

February 2014 Altera Corporation 10-Gbps Ethernet MAC MegaCore Function User Guide
D. ToD Synchronizer
The ToD Synchronizer provides a high accuracy synchronization of time of day from a
master ToD clock to a slave ToD clock. This synchronizer provides more user
flexibility for your design.
The IEEE 1588v2 specifies multiple type of PTP devices, which include the following
clocks:
■ ordinary clock
■ boundary clock
■ transparent clock
■ peer to peer transparent clock
Some of these PTP devices, boundary clock for example, consists of multiple ports
that act as master or slave in the IEEE 1588v2 system. All these ports may share a
common system clock or have its own individual clock. If every port has an
individual ToD running on its own clock, then you must implement a method to
instantiate one ToD clock as the master and the rest of the ToD clocks synchronized to
this master ToD clock.
For this purpose, Altera provides the ToD synchronizer module. This module
synchronizes a master ToD and a slave ToD in the following conditions:
■ Master and slave ToD clocks are in the same frequency within the range of
125 MHz and 156.25 MHz, but different phase.
■ Master and slave ToD clocks are same in the same frequency within the range of
125 MHz and 156.25 MHz, but different PPM.
■ Master and slave ToD clocks are in different frequencies (25 MHz or 156.25 MHz).
D.1. Device Family Support
Table D–1 shows the level of support offered by the ToD clock for each Altera device
family.
Table D–1. Device Family Support
Device Family Support
Arria V GX/GT/GZ/SOC Preliminary
Cyclone V/SOC Preliminary
Stratix V GX/GT Preliminary
Other device families No support