Intel Cyclone 10 GX User Manual page 287

5. Cyclone 10 GX Transceiver PHY Architecture
UG-20070 | 2018.09.24
Figure 182. Interlaken CRC-32 Generator
The Interlaken CRC-32 generator implements the Interlaken protocol.
From the Interlaken Frame Generator
Sy SB
67 0 67
Total Data for CRC-32 Calculation
5.2.1.4. 64B/66B Encoder and Transmitter State Machine (TX SM)
The 64B/66B encoder is used to achieve DC-balance and sufficient data transitions for
clock recovery. It encodes 64-bit XGMII data and 8-bit XGMII control into 10GBASE-R
66-bit control or data blocks in accordance with Clause 49 of the IEEE802.3-2008
specification.
The 66-bit encoded data contains two overhead sync header bits that the receiver PCS
uses for block synchronization and bit-error rate (BER) monitoring. The sync header is
01 for data blocks and 10 for control blocks. Sync headers are not scrambled and are
used for block synchronization. (The sync headers 00 and 11 are not used, and
generate an error if seen.) The remainder of the block contains the payload. The
payload is scrambled and the sync header bypasses the scrambler.
The encoder block also has a state machine (TX SM) designed in accordance with the
IEEE802.3-2008 specification. The TX SM ensures valid packet construction on data
sent from the MAC layer. It also performs functions such as transmitting local faults
under reset, as well as transmitting error codes when the 10GBASE-R PCS rules are
violated.
Note: The 64B/66B encoder is available to implement the 10GBASE-R protocol.
Figure 183. Example Data Pattern for 64B/66B Encoding
XGMII
data
Data
66-bit
encoded
data
Send Feedback
Metaframe
SK Payload Di Sy SB SK
0 67 66 0
TXC<0:3> TXD<0:31> XGMII
f07070707 f07070707 8 fb D
PCS
C C C C C C C C S
0 1 2 3 4 5 6 7
0 63
10 1e 000000 00000000 10
0 65
Interlaken
CRC-32
Generator
Sy SB
Total Data for CRC-32 Calculation
D D 0 D D D D 0 D D D D
1 2 3 4 5 6 7 0 1 2 3
D D D D D D D D D D D
0 1 2 3 4 5 6 7 0 1 2 3
78 D D D D D D D 01 D D D D
1 2 3 4 5 6 7 0 1 2
®
Intel Cyclone
Metaframes with Embedded
CRC-32 Code to Scrambler
Di
SK Payload Sy SB
66 31 0
Calculated CRC-32 Value
Inserted in the 32 Bits
of Diagnostic Word
0 D D D D 1 D D D fd f07070707
4 5 6 7 0 1 2
D D D D D D D T C C C
4 5 6 7 0 1 2 3 0 1 2
D D D D 10 b4 D D D 00000000
3 4 5 6 7 0 1 2
®
10 GX Transceiver PHY User Guide
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