XAUI v12.3 Product Guide
76
PG053 April 6, 2016
Chapter 5
Interfacing to the Core
This chapter describes how to connect to the data interfaces of the core and configuration
and status interfaces of the XAUI core.
Data Interface: Internal XGMII Interfaces
Internal 64-bit SDR Client-side Interface
The 64-bit single-data rate (SDR) client-side interface is based upon a 32-bit XGMII-like
interface. The key difference is a demultiplexing of the bus from 32- bits wide to 64-bits
wide on a single rising clock edge. This demultiplexing is done by extending the bus
upwards so that there are now eight lanes of data numbered 0–7; the lanes are organized
such that data appearing on lanes 4–7 is transmitted or received
later
in time than that in
lanes 0–3.
The mapping of lanes to data bits is shown in
. The lane number is also the index
of the control bit for that particular lane; for example,
xgmii_txc[2]
and
xgmii_txd[23:16]
are the control and data bits respectively for lane 2.
Table 5
‐
1:
xgmii_txd, xgmii_rxd Lanes for Internal 64-bit Client-Side Interface
Lane
xgmii_txd, xgmii_rxd Bits
0
7:0
1
15:8
2
23:16
3
31:24
4
39:32
5
47:40
6
55:48
7
63:56