EP2SGX130GF1508C4 Datasheet, PDF (18/316 Pages) Altera Corporation – Section I. Stratix II GX Device Data Sheet

Transceivers
Transmit State Machine
The transmit state machine operates in either PCI Express mode, XAUI
mode, or GIGE mode, depending on the protocol used. The state machine
is not utilized for certain protocols, such as SONET.
GIGE Mode
In GIGE mode, the transmit state machine converts all idle ordered sets
(/K28.5/, /Dx.y/) to either /I1/ or /I2/ ordered sets. /I1/ consists of a
negative-ending disparity /K28.5/ (denoted by /K28.5/-) followed by a
neutral /D5.6/. /I2/ consists of a positive-ending disparity /K28.5/
(denoted by /K28.5/+) and a negative-ending disparity /D16.2/
(denoted by /D16.2/-). The transmit state machines do not convert any of
the ordered sets to match /C1/ or /C2/, which are the configuration
ordered sets. (/C1/ and /C2/ are defined by [/K28.5/, /D21.5/] and
[/K28.5/, /D2.2/], respectively). Both the /I1/ and /I2/ ordered sets
guarantee a negative-ending disparity after each ordered set.
XAUI Mode
The transmit state machine translates the XAUI XGMII code group to the
XAUI PCS code group. Table 2–5 shows the code conversion.
Table 2–5. Code Conversion
XGMII TXC XGMII TXD
PCS Code-Group
Description
0
00 through FF
Dxx.y
Normal data
1
07
K28.0 or K28.3 or
Idle in ||I||
K28.5
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
See IEEE 802.3
See IEEE 802.3
Reserved code groups
reserved code reserved code groups
groups
1
Other value
K30.7
Invalid XGMII character
The XAUI PCS idle code groups, /K28.0/ (/R/) and /K28.5/ (/K/), are
automatically randomized based on a PRBS7 pattern with an x⁷ + x⁶ + 1
polynomial. The /K28.3/ (/A/) code group is automatically generated
between 16 and 31 idle code groups. The idle randomization on the /A/,
/K/, and /R/ code groups is done automatically by the transmit state
machine.
2–10
Stratix II GX Device Handbook, Volume 1
Altera Corporation
October 2007