GTS Ethernet Intel® FPGA Hard IP User Guide

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

4.4.1.1. Drive the Ethernet Packet to the TX MAC Avalon Streaming Client Interface with Disabled Preamble Passthrough

The followig figue shows the compositio of a Etheet Fame. Be awae of this while you make coectios to the TX MAC Avalo Steamig Cliet Iteface.

Figue 30. Fields ad Fame Boudaies i a Etheet Packet

Whe Peamble Passthough is tued off, do ot dive the Peamble of the Etheet fame o the i_tx_data bus. Dive the fist clock cycle with the destiatio addess, as show i the table below.

Table 26.  Etheet Fame Field Positios i i_tx_data with Peamble Passthough Disabled Attetio: 10GE/25GE equies multiple tasfe cycles fo heade data.
i_tx_clk (Cycle) i_tx_data Etheet Fame Field Desciptio
1-> D0 [63:56]' Dest Add[47:40] The fist octet of the Destiatio Addess, follows Stat Fame Delimite (SFD).
[55:48]' Dest Add[39:32] -
[47:40]' Dest Add[31:24] -
[39:32]' Dest Add[23:16] -
[31:24]' Dest Add[15:8] -
[23:16]' Dest Add[7:0] -
[15:8]' Sc Add[47:40] Whe you tu o Souce Addess Isetio, cotet is eplaced by the souce addess that is cofigued i the txmac_sadd egiste uless i_tx_skip_cc is high.
[7:0]' Sc Add[39:32]
2->D1 [63:56] Sc Add[31:24]
[55:48] Sc Add[23:16]
[47:40] Sc Add[15:8]
[39:32] Sc Add[7:0]
[31:24] Legth/Type[15:8] -
[23:16] Legth/Type[7:0] -
[15:0] -
Note: The byte ode flows fom left to ight o the bus – the fist byte of the MAC destiatio addess is the leftmost byte; the MAC teats this as the fist byte afte the Stat Fame Delimite (SFD). The bit umbeed 0 i the Etheet Specificatio is the ightmost bit of each byte.