Table 1-15: Bits Slip Allowed with the
tx_bitslipboundaryselect
signal
Maximum Bit-Slip Setting
Operation Mode
9
Single width (8 or 10 bit)
19
Double width (16 or 20 bit)
Receiver PCS Datapath
The sub-blocks in the receiver PCS datapath are described in order from the word aligner to the receiver
phase compensation FIFO block.
Table 1-16: Blocks in the Receiver PCS Datapath
Functionality
Block
• Searches for a predefined alignment pattern in the deserialized data to
identify the correct boundary and restores the word boundary during
link synchronization
• Supports an alignment pattern length of 7, 8, 10, 16, 20, or 32 bits
• Supports operation in four modes—manual alignment, bit-slip,
automatic synchronization state machine, and deterministic latency
state machine—in single- and double-width configurations
• Supports the optional programmable run-length violation detection,
polarity inversion, bit reversal, and byte reversal features
Word Aligner
• Compensates for small clock frequency differences of up to ±300 parts
per million (ppm)—600 ppm total—between the upstream transmitter
and the local receiver clocks by inserting or deleting skip symbols when
necessary
• Supports operation that is compliant to the clock rate compensation
function in supported protocols
Rate Match FIFO
• Receives 10-bit data and decodes the data into an 8-bit data and a 1-
bit control identifier—in compliance with Clause 36 of the IEEE 802.3
specification
• Supports operation in single- and double-width modes
8B/10B Decoder
• Halves the FPGA fabric–transceiver interface frequency at the receiver
channel by doubling the receiver output datapath width
• Allows the receiver channel to operate at higher data rates with the
FPGA fabric–transceiver interface frequency that is within maximum
limit
• Supports operation in single- and double-width modes
Byte Deserializer
• Searches for a predefined pattern that must be ordered to the LSByte
position in the parallel data going to the FPGA fabric when you enable
the byte deserializer
Byte Ordering
Transceiver Architecture in Cyclone V Devices
Altera Corporation
CV-53001
Receiver PCS Datapath
1-34
2013.05.06