
Chapter 9: Custom PHY IP Core 9–9
8B/10B Encoder and Decoder Parameters
November 2012 Altera Corporation Altera Transceiver PHY IP Core
User Guide
8B/10B Encoder and Decoder Parameters
The 8B/10B encoder generates 10-bit code groups (control or data word) with proper
disparity from the 8-bit data and 1-bit control identifier. The 8B/10B decoder receives
10-bit data from the rate matcher and decodes it into an 8-bit data and 1-bit control
identifier. Table 9–7 lists the settings available on the 8B/10B tab.
Byte Order Parameters
The byte ordering block is available when the PCS width is doubled at the byte
deserializer. Byte ordering identifies the first byte of a packet by determining whether
the programmed start-of-packet (SOP) pattern is present; it inserts enough pad
characters in the data stream to force the SOP to the lowest order byte lane. Table 9–8
describes the byte order options.
Rate match
insertion/deletion -ve
disparity pattern
0010111100
0101111100
Enter a 10-bit skip pattern (bits 10–19) and a 10-bit control pattern
(bits 0–9). The skip pattern must have neutral disparity.
Create optional rate match
FIFO status ports
On/Off
When enabled, creates the
rx_rmfifoddatainserted
and
rx_rmfifodatadeleted
signals from the rate match FIFO become
output ports.
Table 9–6. Rate Match FIFO Options (Part 2 of 2)
Name Value Description
Table 9–7. 8B/10B Options
Name Value Description
Enable 8B/10B decoder/encoder On/Off
Enable this option if your application requires 8B/10B encoding and
decoding. This option on adds the
tx_datak
<n>,
rx_datak
<n>,
and
rx_runningdisp
<n> signals to your transceiver.
Enable manual disparity control On/Off
When enabled, you can use the
tx_forcedisp
signal to control the
disparity of the 8B/10B encoder. Turning this option on adds the
tx_forcedisp
and
tx_dispval
signals to your transceiver.
Create optional 8B/10B status
port
On/Off
Enable this option to include the 8B/10B
rx_errdetect
and
rx_disperr
error signals at the top level of the Custom PHY IP
Core.
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