GTS Ethernet Intel® FPGA Hard IP User Guide

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

4.5.1. Connect the MII PCS Mode TX Interface

The GTS Etheet Itel® FPGA Had IP TX cliet iteface i PCS vaiatios is Media Idepedet Iteface (MII).

Coect the TX MII iteface (which is a sik) to a MII compliat souce. Coect the iteface accodig to the table below.

Table 33.  MII TX Cliet Iteface SigalsAll iteface sigals ae clocked by the i_clk_tx The sigal ames ae stadad MII iteface sigals.
Sigal Name Width Desciptio
i_tx_mii_d[63:0] 64 bits (10GE/25GE) Dive MII ecoded cotol bytes o Etheet fame cotet o this iput data bus.
  • i_tx_mii_d[7:0] holds the fist byte the IP coe tasmits o the Etheet lik.
  • i_tx_mii_d[0] holds the fist bit the IP coe tasmits o the Etheet lik.
i_tx_mii_c[7:0] 8 bits (10GE/25GE) Fo each cotol byte dive ito i_tx_mii_d bus, dive the coespodig bit high. Fo example, i_tx_mii_c[0] coespods to i_tx_mii_d[7:0].
  • If the value of a bit is 1, the coespodig data byte is a cotol byte.
  • If the value of a bit is 0, the coespodig data byte is data.
i_tx_mii_valid 1 bit Dive this sigal high to qualify the data o cotol bytes o the i_tx_mii_d bus.
o_tx_mii_eady 1 bit Whe this sigal is deasseted, stop divig valid data o the i_tx_mii_d bus sice the IP coe is ot eady to eceive. You must deasset i_tx_mii_valid withi 6 clock cycles of this sigal beig deasseted. Refe Figue 38 fo efeece.
i_tx_mii_am 1 bit Aligmet make isetio bit (Applicable oly fo RS-FEC). Dive this sigal to 0 if Fiecode FEC o NO FEC is eabled.

Dive this sigal to 0 if Fiecode FEC o No FEC is eabled.

The followig wavefom shows how to sed packets diectly to the PCS TX iteface.
Figue 38. Tasmittig Data o the PCS Mode TX Iteface
  • Dive i_tx_mii_valid accodig to the followig ules:
    • Asset the i_tx_mii_valid oly whe the o_tx_mii_eady is asseted, ad deasset oly whe the o_tx_mii_eady is deasseted.
    • Space the i_tx_mii_valid ad o_tx_mii_eady sigals by a fixed latecy betwee oe ad six sigals.
    • Hold the values of i_tx_mii_d ad i_tx_mii_c whe i_tx_mii_valid is low.
  • Bytes ae tasmitted fom Least Sigificat Byte (LSB) to Most Sigificat Byte (MSB) ode. The iitial byte to be tasfeed fom the iteface is epeseted by the 8-bit value i_tx_mii_d[7:0].
  • The fist bit to be tasmitted is the LSB of that byte, which is i_tx_mii_d[0].
Note: The PCS TX iteface is ot SOP aliged. Ay valid odeig of packets i MII fomat is accepted.
Tasmit a stat of packet ad peamble with a SFD byte accodig to the table below.
Table 34.  Sedig a Stat Packet Block with Peamble to the PCS TX Iteface
MII Data MII Cotol Etheet Packet Byte
i_tx_mii_d[7:0] 0xFB i_tx_mii_c[0] 1 Stat of Packet
i_tx_mii_d[15:8] 0x55 i_tx_mii_c[1] 0 Peamble
i_tx_mii_d[23:16] 0x55 i_tx_mii_c[2] 0 Peamble
i_tx_mii_d[31:24] 0x55 i_tx_mii_c[3] 0 Peamble
i_tx_mii_d[39:32] 0x55 i_tx_mii_c[4] 0 Peamble
i_tx_mii_d[47:40] 0x55 i_tx_mii_c[5] 0 Peamble
i_tx_mii_d[55:48] 0x55 i_tx_mii_c[6] 0 Peamble
i_tx_mii_d[63:56] 0xD5 i_tx_mii_c[7] 0 SFD