Introduction
(Ask a Question)This application note describes how the Synchronous Ethernet (SyncE) technology provides a solution for transporting synchronization over Ethernet. SyncE uses frequency synchronization from the physical layer together with a slow protocol and has been standardized by the ITU's Telecommunication Standardization Sector (ITU-T) for frequency distribution. SyncE leverages the PHY layer of Ethernet to transmit frequency to remote sites or other nodes.
SyncE is implemented according to the following ITU-T recommendations:
- G.8261: Defines the architecture of Synchronous Ethernet networks
- G.8262: Specifies the timing characteristics of synchronous Ethernet Equipment Clock (EEC)
- G.8264: Describes the Ethernet Synchronization Messaging Channel (ESMC) which is used to transfer the clock information in the form of Synchronous Status Message (SSM).
PolarFire® Gigabit Transceiver in conjunction with Jitter Attenuating Phase Lock Loop (JAPLL) provides Synchronous Ethernet (SyncE) solution for data rates up to 12.5 Gbps when the transmitter and the receiver are in the same clock domain.
Jitter Attenuating PLL
Jitter Attenuating PLL modulates the transmit clock inorder to lock to an input source. In the absence of any ports, the Jitter Attenuating PLL goes into hold over mode by locking to an on-board reference clock source.