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XRT79L71
PRELIMINARY
21
1-CHANNEL DS3/E3 CLEAR-CHANNEL FRAMERLIU COMBO - CC/HDLC ARCHITECTURE
REV. P2.0.0
NOTE: The Transmit FEAC Controller block is only active if the XRT79L71 is configured to operate in the DS3, C-bit Parity
Framing format.
1.4.5
The Transmit Trail-Trace Message Controller Block (E3, ITU-T G.832 Applications Only)
The purpose of the Transmit Trail-Trace Message Controller block is to permit a given terminal equipment to
repeatedly transmit a "Trail-Trace" Message to the remote terminal equipment, via the TR bytes within the
outbound E3, ITU-T G.832 data-stream.
1.4.6
The Transmit SSM Controller Block (E3, ITU-T G.832 Applications Only)
The purpose of the Transmit SSM Controller Block is to permit a given terminal equipment to repeatedly
transmit the "Synchronization Status Message" to the remote terminal equipment, via the MA byte, within each
outbound E3, ITU-T G.832 frame.
1.4.7
The Transmit LAPD Controller Block
The purpose of the Transmit LAPD Controller block is to permit the user to transmit LAPD/PMDL (Path
Maintenance Data Link) Messages to the remote terminal equipment. The Transmit LAPD Controller block
comes with a LAPD Controller/Transmitter (not to be confused with the Transmit High-Speed HDLC Controller)
and 90 bytes of on-chip RAM (for storage of outbound PMDL Messages) prior to transmission.
1.4.8
The Transmit DS3/E3 Framer Block
The purpose of the Transmit DS3/E3 Framer block is to perform the following functions.
To accept PPP packet and Flag Sequence octets from the Transmit PPP Packet Processor block and to map
all of this data into the payload bits within each outbound DS3 or E3 frame.
To transmit the resulting framed DS3 or E3 data-stream to the Transmit DS3/E3 LIU Block. In this case, the
user can also configure the Transmit DS3/E3 Framer block to do the following.
a. Transmit an AIS Pattern (upon software command)
b. Transmit a DS3 Idle Pattern (upon software command)
c. Automatically transmit the FERF/RDI whenever the Receive DS3/E3 Framer block (within the very same
XRT79L71) declares the LOS, LOF/OOF or AIS defect conditions.
d. Automatically transmit the FEBE/REI indicator whenever the Receive DS3/E3 Framer block detects CP-
bit or Framing bit errors within the incoming DS3 data-stream (for DS3, C-bit Parity Applications only)
e. Automatically transmit the FEBE/REI indicator whenever the Receive DS3/E3 Framer block detects BIP-
8 errors within the incoming E3 data-stream (for E3, ITU-T G.832 Applications).
1.4.9
The Transmit DS3/E3 LIU Block
The purpose of the Transmit DS3/E3 LIU Block is to accept the outbound DS3/E3 data-stream from the
Transmit DS3/E3 Framer block and to perform the following functions on this data.
Encode this data into the B3ZS Line Code (for DS3 Applications) or the HDB3 Line Code (for E3
Applications)
To convert this outbound DS3 or E3 data-stream into a DS3/E3 line signal and transmit this signal to the
remote terminal equipment
To generate and transmit DS3 pulses that comply with the Isolated Pulse Template requirements per
Bellcore GR-499-CORE
To generate and transmit E3 pulses that comply with the ITU-T G.703 Pulse Template requirements for E3
Applications.
1.4.10
The Receive DS3/E3 LIU Block
The purpose of the Receive DS3/E3 LIU Block is to receive a DS3/E3 line signal from the remote terminal
equipment, and perform the following operations on this incoming line signal.