XAUI v12.3 Product Guide
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PG053 April 6, 2016
Chapter 4
Core Architecture
This chapter describes the overall architecture of the XAUI core and also describes the
major interfaces to the core.
System Overview
XAUI is a four-lane, 3.125 Gb/s per-lane serial interface. 20 G – XAUI is supported in
Zynq®-7000, Kintex®-7, Virtex®-7, and Artix®-7 devices (–2 speed grades) and
UltraScale architecture using four transceivers at 6.25 Gb/s. Each lane is a differential pair,
carrying current mode logic (CML) signaling; the data on each lane is 8B/10B encoded
before transmission. Special code groups are used to allow each lane to synchronize at a
word boundary and to deskew all four lanes into alignment at the receiving end. The XAUI
standard is fully specified in clauses 47 and 48 of the 10-Gigabit Ethernet specification
IEEE
Std. 802.3-2012
.
The XAUI standard was initially developed as a means to extend the physical separation
possible between Media Access Controller (MAC) and physical-side interface (PHY)
components in a 10-Gigabit Ethernet system distributed across a circuit board, and to
reduce the number of interface signals in comparison with the Ten Gigabit Ethernet Media
Independent Interface (XGMII).
shows the XAUI core being used to connect to a
10-Gigabit Expansion Pack (XPAK) optical module.