DS3181/DS3182/DS3183/DS3184
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10.8 DS3/E3 PLCP Framer
10.8.1 General Description
The PLCP Framer demaps the ATM cells from the DS3/E3 PLCP data stream in the receive direction and maps
ATM cells into the DS3/E3 PLCP data stream in the transmit direction.
The receive direction extracts the PLCP frame from the DS3/E3 data stream, performs frame processing, and
outputs the cells with a beginning of cell indication via the payload interface.
The transmit direction inputs the cells via the payload interface, generates the frame, and inserts the PLCP frame
into the DS3/E3 data stream. See
Figure 10-31 for the location of the PLCP framer in the DS318x devices.
Figure 10-31. PLCP Framer Functional Diagram
DS3/E3
Transmit
LIU
IEEE P1149.1
JTAG Test
Access Port
Microprocessor
Interface
HDLC
FEAC
LLB
DL
B
DS3 / E3
Transmit
Formatter
DS3 / E3
Receive
Framer
Trail
Trace
Buffer
Tx Cell
Processor
Tx
FIFO
Sy
st
em
Int
er
fac
e
Rx Cell
Processor
Rx
FIFO
Tx Packet
Processor
SL
B
Rx Packet
Processor
DS3/E3
Receive
LIU
TAIS
TUA1
TX FRAC/
PLCP
RX FRAC/
PLCP
Clock Rate
Adapter
TX BERT
RX BERT
PL
B
AL
B
UA1
GEN
B3ZS/
HDB3
Encoder
B3ZS/
HDB3
Decoder
10.8.2 Features
DS3 PLCP frame ATM cell extraction and insertion – Accepts a DS3 payload and performs DS3 PLCP
overhead termination and generation.
E3 PLCP frame ATM cell extraction and insertion – Accepts a G.751 E3 payload and performs E3 PLCP
overhead termination and generation.
Generates and detects alarms and errors – In the receive direction, PLCP alarm conditions (OOF, LOF,
COFA, and RAI) and errors (framing, parity, and REI) are detected on the receive signal. In the transmit
direction, alarm conditions and errors can be inserted into the transmit data stream.
Receive overhead extraction port – Extracts all PLCP overhead from the receive signal and outputs it on a
serial interface (RPOH pin).
Externally controlled transmit overhead insertion port – Can insert all PLCP overhead into the transmit
signal from a serial interface. Overhead insertion is fully controlled via the serial overhead interface (TPOH,
TPOHEN, TPOHSOF, TPOHCLK).
Full Duplex serial HDLC channel extraction/insertion – An HDLC channel can be extracted from and/or
inserted into the F1, M1, M2, or M1 and M2 bytes in the PLCP data stream.
Full Duplex serial Trail Trace extraction/insertion – A trail trace can be extracted from and/or inserted into
the F1 byte in the PLCP data stream.
