184.108.40.206.10. Multiple 25G Synchronous Ethernet Channels
For multi-channel synchronous Ethernet configuration, one TX eFIFO is instantiated for each Ethernet channel when Enable SyncE With Dedicated Reference Clock Per Channel is enabled. The write data valid signal of the FIFO is connected internally to the custom cadence port of hard IP.
Similar to single channel configuration, RX recovered clock of each channel is fed to on-board clock cleaner for jitter removal. The clock cleaner should filter and generate the correct frequency for i_clk_ref input reference clock. After power up, the clock cleaner has to provide default reference clock before RX recovered clock is available at o_clk_rec_div64/66.
- Dedicated reference clock: Recovered clock from each channel is fed to input reference clock of respective channel. For example, connect filtered RX clock from Channel 0 to i_clk_ref of Channel 0, filtered RX clock from Channel 1 to i_clk_ref of Channel 1. Parameter Enable SyncE With Dedicated Reference Clock Per Channel must be enabled to support this method.
- Common reference clock: Only one of the RX recovered clocks to be connected to input reference clock of all channels. For example, connect filtered RX clock from Channel 0 to i_clk_ref of Channel 0 and Channel 1. Make sure that all channels have the same input reference clock frequency.