ep2sgx30c Altera Corporation, ep2sgx30c Datasheet - Page 18

• Manufacturer Part Number: ep2sgx30c
• Description: Stratix Ii Gx Device Data Sheet
• Manufacturer: Altera Corporation

Transceivers
2–10
Stratix II GX Device Handbook, Volume 1
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.
The XAUI PCS idle code groups, /K28.0/ (/R/) and /K28.5/ (/K/), are
automatically randomized based on a PRBS7 pattern with an x
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.
XGMII TXC
Table 2–5. Code Conversion
0
1
1
1
1
1
1
1
1
See IEEE 802.3
reserved code
00 through FF
Other value
XGMII TXD
groups
FD
9C
FB
FE
07
07
Table 2–5
reserved code groups
K28.0 or K28.3 or
PCS Code-Group
See IEEE 802.3
shows the code conversion.
K28.5
K28.5
K28.4
K27.7
K29.7
K30.7
K30.7
Dxx.y
Invalid XGMII character
Reserved code groups
Altera Corporation
Normal data
Description
Idle in ||T||
Sequence
Terminate
Idle in ||I||
Error
Start
October 2007
7
+ x
6
+ 1