Altera Corporation
2–175
October 2007
Stratix II GX Device Handbook, Volume 2
Stratix II GX Transceiver Architecture Overview
simultaneously across all channels during IPG or idle conditions. If the
FIFO counter is less than five, the receivers insert the /R/ code-group
simultaneously across all channels during IPG or idle conditions.
1
This circuitry compensates for ±100 PPM frequency variations.
PCS Code Group to XGMII Character Mapping
In XAUI mode, the 8B/10B decoder in Stratix II GX devices is controlled
by a global receiver state machine that maps various PCS code groups
into specific 8-bit XGMII codes.
Table 2–40
lists the PCS code group to
XGMII character mapping.
XGMII Character to PCS Code-Group Mapping
In XAUI mode, the 8B/10B encoder in Stratix II GX devices is controlled
by a global transmitter state machine that maps various 8-bit XGMII
codes to 10-bit PCS code groups. This state machine complies with the
IEEE 802.3ae PCS transmit specification.
Figure 2–126
shows the PCS
transmit source state diagram specified in clause 48 of the IEEE P802.3ae.
Table 2–40. PCS Code Group to XGMII Character Mapping
XGMII RXC
XGMII RXD
(1)
PCS Code Group
Description
0
00 through FF
Dxx.y
Normal data
transmission
1
07
K28.0, 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
FE
Invalid code group Received code
group
Note to
Table 2–40
:
(1)
Values in RXD column are in hexadecimal.