F-Tile Architecture and PMA and FEC Direct PHY IP User Guide

ID 683872
Date 11/04/2024
Public
Document Table of Contents

5.5. Enabling Custom Cadence Generation Ports and Logic

This F-tile PMA/FEC Diect PHY desig uses System PLL clockig mode to clock the digital datapath of the FGT PMA lae. Because the system PLL fequecy (830.078125MHz) is geate tha the PMA clock fequecy (805.6640625MHz), you must eable custom cadece geeatio logic pots, ad eable the logic optio i the IP paamete edito.

  • You must use tx_cadece pot output to asset ad de-asset the TX PMA Iteface data valid bit (oe of the bits i TX paallel data). Refe to Paallel Data Mappig Ifomatio.
  • You must coect tx_cadece_fast_clk to tx_clkout/tx_clkout2 with clock souce System PLL Clock / 2 (415.0390625MHz).
  • You must coect tx_cadece_slow_clk to tx_clkout/tx_clkout2 with clock souce Wod clock o Bod clock / 2 (402.83203125 MHz)
Figue 110. Eablig Custom Cadece Geeatio Pots ad Logic

Rate Match FIFO Requiemet

The followig guidelies apply to the elastic FIFO equiemet betwee use FPGA coe logic ad the F-Tile PMA/FEC Diect PHY Itel® FPGA IP:

  • If the use FPGA coe logic is uig at same fequecy as system PLL fequecy/2 (that is, 415.0390625MHz), the thee is o elastic FIFO equiemet betwee the use FPGA coe logic ad the F-Tile PMA/FEC Diect PHY Itel® FPGA IP.
  • If the use FPGA coe logic is uig at PMA clock fequecy/2 (that is, 402.83203125 MHz), this equies elastic FIFO betwee the use FPGA coe logic ad the F-tile coe iteface FIFO to tasfe fom PMA clock fequecy domai to system PLL clock fequecy domai ad must be implemeted by the use.