Altera Stratix GX Transceiver - Manual (Page 115)

Altera Corporation 5–3
January 2005 Stratix GX Transceiver User Guide
XAUI Mode
XAUI functions as a self-managed interface because code-group
synchronization, channel deskew, and clock domain decoupling are
handled with no upper layer support requirements. These features are
accomplished based on Physical Coding Sublayer (PCS) code-groups that
are used during the Inter-Packet Gap (IPG) time and during idle periods.
PCS code-groups are mapped by the XGMII Extender Sublayer (XGXS) to
XGMII characters, as specified in
Table 5–1 .
Figure 5–2 shows an example of the mapping between XGMII characters
to the PCS code-groups used in XAUI. The idle characters are mapped to
a pseudorandom sequence of ||A||, ||R||, and ||K|| code-groups.
Table 5–1. XGMII Character to PCS Code-Group Mapping Note (1)
XGMII TXC XGMII TXD PCD Code-Group Description
0 00 through FF Dxx,y Normal data
transmission
1 07 K28.0 or K28.3 or
K28.5
Idle in ||I||
1 07 K28.5 Idle in ||T||
1 9C K28.4 Sequence
1 FB K27.7 Start
1 FD K29.7 Terminate
1 FE K30.7 Error
1 Reserved XGMII
character
1 Any other value K30.7 Invalid XGMII
character
Note to Table 5–1 :
(1) Values in TXD column are in hexadecimal.