GTS Ethernet Intel® FPGA Hard IP User Guide

ID 817676
Date 10/12/2024
Public
Document Table of Contents

4.6.1.1. Insert Alignment Marker

Figue 43. Iset Aligmet Makes

Whe the PCS66 TX iteface is used fo FlexE mode, you ca cotoll the timig of aligmet make isetio fom the fabic.

Fo 10GE chaels, the sigal causes the cycle to be teated as ivalid fo PCS pocessig (o chages to scamble).

I FlexE mode, the timig of aligmet make isetio is vey igid. Aligmet makes caot be delayed without disuptig the Etheet lik. Use valid cycles to cout the aligmet makes. Whe i_tx_pcs66_valid is low, the aligmet make coutes ad iput must feeze.

Asset i_tx_pcs66_am to have the TX PCS iset aligmet makes. Without FEC, i_tx_pcs66_am is optioal ad tie the sigal low.

I FEC modes, the TX datapath does ot exit eset util at least two aligmet make peiods pass. You must stat divig i_tx_pcs66_am at the pope iteval befoe o_tx_laes_stable goes high. You ca dive the sigal as soo as o_tx_pll_locked is asseted ado_tx_pcs66_eady stats togglig.

The umbe of cycles fo i_tx_mii_am to emai high depeds o the ate of the iteface, Specifically:
  • 25GE with RS-FEC: 4 cycles
The umbe of valid cycle fo AM peiod depeds o the ate of the iteface ad whethe i simulatio o hadwae. I simulatio, its commo to use a educed AM peiod fo both sides of the lik is commoly used to icease lock-time speed. Specifically:
  • 25GE with RS-FEC: 2552 (No - PTP desig)
  • 25GE with RS-FEC: 5112 (PTP Desig)
I hadwae: 25GE with RS-FEC: 81920