Altera Transceiver PHY IP Core - Manual (Page 221)

Table 9-5: Word Aligner Options
Name Value Description
Word alignment mode
Manual In this mode you enable the word alignment
function by asserting
rx_enapatternalign
using the Avalon-MM interface. When the
PCS exits reset, the word aligner automati‐
cally performs an initial alignment to the
specified word alignment pattern when the
interface between the PCS and PMA is 16 or
20 bits. For other cases, you must assert
rx_
enapatternalign
to initiate another pattern
alignment.
rx_enapatternalign
is edge
sensitive in most cases; however, if the
PMA-PCS interface width is 10 bits, it is level
sensitive.
Bit slipping You can use bit slip mode to shift the word
boundary using the Avalon-MM interface.
For every rising edge of the rx_bitslip signal,
the word boundary is shifted by 1 bit. Each
bit slip removes the earliest received bit from
the received data.
Automatic
synchronization state
machine
In this mode, word alignment is controlled by
a programmable state machine. This mode
can only be used with 8B/10B encoding. The
data width at the word aligner can be 10 or 20
bits. You can specify the following
parameters:
• Number of consecutive valid words
before sync state is reached: Specifies the
number of consecutive valid words needed
to reduce the built up error count by 1.
Valid values are 1-256.
• Number of bad data words before loss of
sync state: Specifies the number of bad
data words required for alignment state
machine to enter loss of sync state. Valid
values are 1-256.
• Number of valid patterns before sync
state is reached: Specifies the number of
consecutive patterns required to achieve
synchronization. Valid values are 1-256.
Create optional word aligner status ports:
When enabled the
rx_syncstatus
and
rx_
patterndetect
status ports are created.
• Word alignment pattern length: Allows
you to specify a 7-, 10-, or 20-bit pattern
for use in the word alignment state
machine. The 20-bit pattern is available
when the PMA-PCS interface width is 20
bits.
• Word alignment pattern: Allows you to
specify a word alignment pattern.
9-8 Word Alignment Parameters
UG-01080
2015.01.19
Altera Corporation Custom PHY IP Core
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