Chapter 2: Arria GX Architecture
2–7
Transceivers
Transmit State Machine
The transmit state machine operates in either PCI Express (PIPE) mode, XAUI mode,
or GIGE mode, depending on the protocol used.
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. The /I1/ set consists of a negative-ending
disparity /K28.5/ (denoted by /K28.5/-), followed by a neutral /D5.6/. The /I2/ set
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 2–3 lists the code conversion.
Table 2–3. On-Chip Termination Support by I/O Banks
XGMII TXC
XGMII TXD
PCS Code-Group
Description
Normal data
0
1
1
1
1
1
1
1
00 through FF
Dxx.y
07
07
9C
FB
FD
FE
K28.0 or K28.3 or K28.5
Idle in ||I||
Idle in ||T||
Sequence
Start
K28.5
K28.4
K27.7
K29.7
K30.7
Terminate
Error
Refer to IEEE 802.3 reserved code
groups
Refer to IEEE 802.3 reserved code
groups
Reserved code 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 ×7 + ×6 + 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 automatically done by
the transmit state machine.
Serializer (Parallel-to-Serial Converter)
The serializer block clocks in 8- or 10-bit encoded data from the 8B/10B encoder using
the low-speed parallel clock and clocks out serial data using the high-speed serial
clock from the central or local clock divider blocks. The serializer feeds the data LSB to
MSB to the transmitter output buffer.
© December 2009 Altera Corporation
Arria GX Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
