HC4GX15 Datasheet, PDF (432/668 Pages) Altera Corporation – HardCopy IV Device Handbook

1–168
Chapter 1: HardCopy IV GX Transceiver Architecture
Functional Modes
Two flags, rx_rmfifodatadeleted and rx_rmfifodatainserted, indicating
rate match FIFO deletion and insertion events, respectively, are forwarded to the core
fabric. Both the rx_rmfifodatadeleted and rx_rmfifodatainserted flags are
asserted for two clock cycles for each deleted and inserted /I2/ ordered set,
respectively.
Figure 1–136 shows an example of rate match FIFO deletion in the case where three
symbols are required to be deleted. Because the rate match FIFO can only delete /I2/
ordered set, it deletes two /I2/ ordered sets (four symbols deleted).
Figure 1–136. Rate Match Deletion in GIGE Mode
/I2/ SKIP Symbol Deleted
First /I2/ Skip Ordered Set Second /I2/ Skip Ordered Set Third /I2/ Skip Ordered Set
datain
Dx.y
K28.5
D16.2
K28.5
D16.2
K28.5
D16.2
Dx.y
dataout
Dx.y
K28.5
D16.2
Dx.y
rx_rmfifodatadeleted
Figure 1–137 shows an example of rate match FIFO insertion in the case where one
symbol is required to be inserted. Because the rate match FIFO can only delete /I2/
ordered set, it inserts one /I2/ ordered set (two symbols inserted).
Figure 1–137. Rate Match Insertion in GIGE Mode
First /I2/ Ordered Set
datain
Dx.y
K28.5
D16.2
Second /I2/ Ordered Set
K28.5
D16.2
dataout
Dx.y
K28.5
D16.2
K28.5
D16.2
K28.5
D16.2
Dx.y
rx_rmfifodatainserted
SONET/SDH Mode
SONET/SDH is one of the most common serial-interconnect protocols used in
backplanes deployed in communications and telecom applications. SONET/SDH
defines various optical carrier (OC) sub-protocols for carrying signals of different
capacities through a synchronous optical hierarchy.
SONET/SDH Frame Structure
Base OC-1 frames are byte-interleaved to form SONET/SDH frames. For example,
12 OC-1 frames are byte-interleaved to form one OC-12 frame; 48 OC-1 frames are
byte-interleaved to form one OC-48 frame, and so on. SONET/SDH frame sizes are
constant, with a frame transfer rate of 125 μs.
HardCopy IV Device Handbook Volume 3
© June 2009 Altera Corporation