XRT79L71_07 Datasheet, PDF (69/109 Pages) Exar Corporation – 1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - HARDWARE

XRT79L71
REV. 1.0.0
1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - HARDWARE
The purpose of the Transmit FEAC Controller block is to permit the user to transmit FEAC (Far-End Alarm &
Control) Messages to the remote terminal equipment.
NOTE: The Transmit FEAC Controller block is only active if the XRT79L71 is configured to operate in the DS3, C-bit Parity
Framing format.
The Transmit Trail-Trace Message Controller Block (E3, ITU-T G.832 Applications Only)
The Transmit SSM Controller Block (E3, ITU-T G.832 Applications Only)
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.
The Transmit PLCP Processor Block (Can be by-passed)
The purpose of the Transmit PLCP Processor block is to perform the following functionsl
• To accept ATM cells from the Transmit ATM Cell Processor Block and to pack 12 of these ATM cells into a
PLCP frame
• As the Transmit PLCP Processor block creates these PLCP frames, it will also do the following
a. Automatically transmit the PLCP RAI (Remote Alarm Indicator) to the remote terminal whenever the
corresponding Near-End Receive PLCP Processor block declares the PLCP LOF defect condition.
b. Automatically transmits the PLCP FEBE (Far-End Block Error) condition to the remote terminal
whenever the corresponding near-end Receive PLCP Processor block detects PLCP B1 byte errors
within its incoming PLCP data-stream.
• The Transmit PLCP Processor block can be commanded to transmit the PLCP RAI indicator upon Software
command
• The Transmit PLCP Processor block can be commanded to transmit the PLCP FEBE indicator upon
Software command
• Routes these outbound PLCP frames to the Transmit DS3/E3 Framer block
• Can be by-passed for Direct-Mapped ATM Applications.
The Transmit DS3/E3 Framer Block
The purpose of the Transmit DS3/E3 Framer block is to perform the following functions.
• To accept ATM cell data from the Transmit ATM Cell Processor block and to map this ATM cell data into the
payload bits within each outbound DS3 or E3 frame (for Direct Mapped ATM Applications)
• To accept PLCP frames from the Transmit PLCP Processor block and to map these PLCP frames into the
payload bits within each outbound DS3 or E3 frames (for PLCP Applications)
• To transmit this 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 indicator whenever the Receive DS3/E3 Framer block (within this
particular XRT79L71) declares the LOS, LOF/OOF or AIS defect condition.
d. Automatically transmits the FEBE/REI indicator whenever the corresponding near-end Receive DS3/E3
Framer block detects CP-bit or Framing bit errors within the incoming DS3 data-stream (for DS3 C-bit
Parity Applications).
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).
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