
9–8 Chapter 9: Custom PHY IP Core
Rate Match FIFO Parameters
Altera Transceiver PHY IP Core November 2012 Altera Corporation
User Guide
Table 9–5 provides more information about the word alignment function.
f For more information about the word aligner, refer to “Word Alignment” in
Transceiver Architecture in Stratix V Devices in the Stratix V Device Handbook, Transceiver
Architecture in Arria V Devices in the Arria V Device Handbook, or “Word Aligner” in
Transceiver Architecture in Cyclone V Devices.
Rate Match FIFO Parameters
The rate match FIFO compensates for small clock frequency differences between the
upstream transmitter and the local receiver clocks by inserting or removing skip
(SKP) symbols or ordered-sets from the inter-packet gap (IPG) or idle streams. It
deletes SKP symbols or ordered-sets when the upstream transmitter reference clock
frequency is greater than the local receiver reference clock frequency. It inserts SKP
symbols or ordered-sets when the local receiver reference clock frequency is greater
than the upstream transmitter reference clock frequency.
If you enable the rate match FIFO, the MegaWizard Plug-In Manager provides
options to enter the rate match insertion and deletion patterns. The lower 10 bits are
the control pattern, and the upper 10 bits are the skip pattern. Table 9–6 lists the
settings available on the Rate Match tab.
Table 9–5. Word Aligner Options
PMA-PCS
Interface Width
(bits)
Word Alignment
Mode
Word Alignment
Pattern Length
(bits)
Word Alignment Behavior
8
Manual
alignment
8, 16
User-controlled signal starts alignment process. Alignment
occurs once unless signal is re-asserted.
10
Manual alignment
7, 10
User-controlled signal starts alignment process. Alignment
occurs once unless signal is re-asserted.
Automatic
synchronized
state machine
Data must be 8B/10B encoded and aligns to selected word
aligner pattern.
16
Manual
alignment
8, 16, 32
User-controlled signal starts alignment process. Alignment
occurs once unless signal is re-asserted.
20
Manual
alignment
8, 16, 32
User-controlled signal starts alignment process. Alignment
occurs once unless signal is re-asserted.
Automatic
Synchronized State
Machine
7, 10, or 20 bits
Automatically selected word aligner pattern length and
pattern.
Table 9–6. Rate Match FIFO Options (Part 1 of 2)
Name Value Description
Enable rate match FIFO On/Off
Turn this option on, to enable the rate match functionality. Turning
this option on adds the
rx_rmfifodatainserted
, and
rx_rmfifodatadeleted
status signals to your PHY.
Rate match
insertion/deletion +ve
disparity pattern
1101000011
1010000011
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.
Kommentare zu diesen Handbüchern