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Altera Corporation
2–25
February 2005
Stratix GX Device Handbook, Volume 1
Stratix GX Transceivers
Receiver State Machine
The receiver state machine operates in GigE and XAUI modes. In GigE
mode, the receiver state machine replaces invalid code groups with
9’h1FE. In XAUI mode, the receiver state machine translates the XAUI
PCS code group to the XAUI XGMII code group.
Table 2–8 shows the
code conversion. The conversion adheres to the IEEE 802.3ae
specification.
Byte Deserializer
The byte deserializer takes a single width word (8 or 10 bits) from the
transceiver logic and converts it into double-width words (16 or 20 bits)
to the phase compensation FIFO buffer. The byte deserializer is bypassed
when single width mode (8 or 10 bits) is used at the PLD interface.
Phase Compensation FIFO Buffer
The receiver phase compensation FIFO buffer resides in the transceiver
block at the programmable logic device (PLD) boundary. This buffer
compensates for the phase difference between the recovered clock within
the transceiver and the recovered clock after it has transferred to the PLD
core. The phase compensation FIFO buffer is four words deep and cannot
be bypassed.
Table 2–8. Code Conversion
XGMII RXC
XGMII RXD
PCS code-group
Description
0
00 through FF
Dxx.y
Normal Data
1
07
K28.0 or K28.3 or K28.5
Idle in ||I||
1
07
K28.5
Idle in ||T||
9C
K28.4
Sequence
1
FB
K27.7
Start
1
FD
K29.7
Terminate
1FE
K30.7
Error
1
FE
Invalid code group
Invalid XGMII character
1
See IEEE 802.3 reserved code
groups
See IEEE 802.3 reserved
code groups
Reserved code groups