Chapter 6

Ethernet AVB Endpoint Transmission

As illustrated in Figure 5-1, data for transmission over an AVB network can be obtained from three types of sources:

1.AV Traffic. For transmission from the “Tx AV Traffic I/F” of the core.

2.Precise Timing Protocol (PTP) Packets. Initiated by the software drivers using the dedicated hardware “Tx PTP Packet Buffer.”

3.Legacy Traffic. For transmission from the “Tx Legacy Traffic I/F” of the core.

Tx Legacy Traffic I/F

The signals forming the Tx Legacy Traffic I/F are defined in Table 5-2. All signals are synchronous to the Tri-Mode Ethernet MAC transmitter clock, tx_clk, which must always be qualified by the corresponding clock enable, tx_clk_en (see Table 5-1).

This interface is intentionally identical to the client transmitter interface of the supported Xilinx Tri-Mode Ethernet MAC core (there is a one-to-one correspondence between signal names of the block-level wrapper from the Tri-Mode Ethernet MAC example design, after the legacy_ prefix is removed). This provides backwards compatibility–all existing MAC client-side designs can connect to the legacy Ethernet port unmodified.

Ethernet AVB Endpoint User Guide

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UG492 July 23, 2010

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Xilinx UG492 manual Ethernet AVB Endpoint Transmission, Tx Legacy Traffic I/F