HC4GX15 Datasheet, PDF (414/668 Pages) Altera Corporation – HardCopy IV Device Handbook

1–150
Chapter 1: HardCopy IV GX Transceiver Architecture
Functional Modes
Figure 1–120 shows the relationships between the XGMII and XAUI layers.
Figure 1–120. XAUI and XGMII Layers
LAN Carrier Sense Multiple
Access/Collision Detect (CSMA/CD)
Layers
Higher Layers
OSI
Reference
Model Layers
Application
Presentation
Session
Transport
Network
Data Link
Physical
Logical Link Control (LLC)
MAC Control (Optional)
Media Access Control (MAC)
Reconciliation
Optional
XGMII
Extender
XGMII Extender Sublayer
XGMII Extender Sublayer
PCS
PMA
PMD
Medium
10 Gb/s
10 Gigabit Media Independent Interface
10 Gigabit Attachment Unit Interface
10 Gigabit Media Independent Interface
Physical Layer Device
Medium Dependent Interface
The XGMII interface consists of four lanes of 8 bits. At the transmit side of the XAUI
interface, the data and control characters are converted within the XGXS into an
8B/10B encoded data stream. Each data stream is then transmitted across a single
differential pair running at 3.125 Gbps (3.75 Gbps for HiGig). At the XAUI receiver,
the incoming data is decoded and mapped back to the 32-bit XGMII format. This
provides a transparent extension of the physical reach of the XGMII and also reduces
the interface pin count.
In HardCopy IV GX XAUI functional mode, the interface between the transceiver and
core fabric is 64 bits wide (four channels of 16 bits each) at single data rate.
XAUI functions as a self-managed interface because code group synchronization,
channel deskew, and clock domain decoupling is handled with no upper layer
support requirements. This functionality is based on the PCS code groups that are
used during the IPG time and idle periods. PCS code groups are mapped by the XGXS
to XGMII characters, as specified in Table 1–41.
Table 1–41. XGMII Character to PCS Code-Group Mapping (Part 1 of 2)
XGMII TXC
0
XGMII TXD (1)
00 through FF
PCD Code Group
Dxx,y
1
07
K28.0 or K28.3 or
K28.5
Description
Normal data
transmission
Idle in ||I||
HardCopy IV Device Handbook Volume 3
© June 2009 Altera Corporation