DS3181 Datasheet, PDF (166/389 Pages) Maxim Integrated Products – Single/Dual/Triple/Quad ATM/Packet PHYs with Built-In LIU

DS3181/DS3182/DS3183/DS3184
10.10 DS3/E3 Framer / Formatter
10.10.1 General Description
The Receive DS3/E3 Framer receives a unipolar DS3/E3 signal, determines frame alignment and extracts the
DS3/E3 overhead in the receive direction. The Transmit DS3/E3 Formatter receives a DS3/E3 payload, generates
framing, inserts DS3/E3 overhead, and outputs a unipolar DS3/E3 signal in the transmit direction.
The Receive DS3/E3 Framer receives a DS3/E3 signal, determines the frame alignment, extracts the DS3/E3
overhead, and outputs the payload with frame and overhead
The Transmit DS3/E3 Formatter receives a DS3/E3 payload from the ATM/Packet Processor, generates a DS3/E3
frame, optionally inserts DS3/E3 overhead, and transmits the DS3/E3 signal.
Refer to Figure 10-39 for the location of the DS3/E3 Framer/Formatter blocks in the DS318x devices.
Figure 10-39. Framer Detailed Block Diagram
DS3/E3
Transmit
LIU
DS3/E3
Receive
LIU
Clock Rate
A dapter
TAIS
TUA1
B3ZS/
HDB3
Encoder
DS3 / E3
Transmit
Formatter
Trail
FEAC Trace HDLC
Buf f er
TX FRAC/
PLCP
B3ZS/
HDB3
Decoder
DS3 / E3
Receive
Framer
IEEE P1149.1
JTAG Test
Access Port
UA 1
GEN
RX FRAC/
PLCP
Tx Cell
Processor
Tx Packet
Processor
TX BERT
RX BERT
Rx Packet
Processor
Rx Cell
Processor
Tx
FIFO
Rx
FIFO
Microprocessor
Interf ac e
10.10.2 Features
10.10.2.1 Transmit Formatter
· Programmable DS3 or E3 formatter – Accepts a DS3 (M23 or C-bit) or E3 (G.751 or G.832) signal and
performs DS3/E3 overhead generation.
· Arbitrary framing format support – Generates a signal with an arbitrary framing format. The line
overhead/stuff periods are added into the data stream using an overhead mask signal.
· Generates alarms and errors – DS3 alarm conditions (AIS, RDI, and Idle) and errors (framing, parity, and
FEBE), or E3 alarm conditions (AIS and RDI/RAI) and errors (framing, parity, and REI) can be inserted into the
outgoing data stream.
· Externally controlled serial DS3/E3 overhead insertion port – Can insert all DS3 or E3 overhead via a
serial interface. DS3/E3 overhead insertion is fully controlled via the serial overhead interface.
· HDLC overhead insertion – An HDLC channel can be inserted into the DS3 or E3 data stream.
· FEAC insertion – A FEAC channel can be inserted into the DS3 or E3 data stream.
· Trail Trace insertion – Inputs and inserts the G.832 E3 TR byte.
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