XRT86VL3X_07 Datasheet, PDF (1/153 Pages) Exar Corporation – T1/E1/J1 FRAMER/LIU COMBO - ARCHITECTURE DESCRIPTION

XRT86VL3x
T1/E1/J1 FRAMER/LIU COMBO - ARCHITECTURE DESCRIPTION
JANUARY 2007
REV. 1.2.2
GENERAL DESCRIPTION
The XRT86VL3x is a 1.544 Mbit/s or 2.048 Mbit/s
DS1/E1/J1 framer and LIU integrated solution
featuring R³ technology (Relayless, Reconfigurable,
Redundancy) that comes in a 2-channel, 4-channel,
or 8-channel package. The physical interface is
optimized with internal impedance, and with the
patented pad structure, the XRT86VL3x provides
protection from power failures and hot swapping.
The XRT86VL3x contains an integrated DS1/E1/J1
framer and LIU which provide DS1/E1/J1 framing and
error accumulation in accordance with ANSI/ITU_T
specifications. Each framer has its own framing
synchronizer and transmit-receive slip buffers. The
slip buffers can be independently enabled or disabled
as required and can be configured to frame to the
common DS1/E1/J1 signal formats.
Each Framer block contains its own Transmit and
Receive T1/E1/J1 Framing function. There are 3
Transmit HDLC controllers per channel which
encapsulate contents of the Transmit HDLC buffers
into LAPD Message frames. There are 3 Receive
HDLC controllers per channel which extract the
payload content of Receive LAPD Message frames
from the incoming T1/E1/J1 data stream and write the
contents into the Receive HDLC buffers. Each framer
also contains a Transmit and Overhead Data Input
port, which permits Data Link Terminal Equipment
direct access to the outbound T1/E1/J1 frames.
Likewise, a Receive Overhead output data port
permits Data Link Terminal Equipment direct access
to the Data Link bits of the inbound T1/E1/J1 frames.
The XRT86VL3x fully meets all of the latest T1/E1/J1
specifications: ANSI T1/E1.107-1988, ANSI T1/
E1.403-1995, ANSI T1/E1.231-1993, ANSI T1/
E1.408-1990, AT&T TR 62411 (12-90) TR54016, and
ITU G-703, G.704, G706 and G.733, AT&T Pub.
43801, and ETS 300 011, 300 233, JT G.703, JT
G.704, JT G706, I.431. Extensive test and diagnostic
functions include Loop-backs, Boundary scan,
Pseudo Random bit sequence (PRBS) test pattern
generation, Performance Monitor, Bit Error Rate
(BER) meter, forced error insertion, and LAPD
unchannelized data payload processing according to
ITU-T standard Q.921.
Applications and Features (next page)
FIGURE 1. XRT86VL3X N-CHANNEL DS1 (T1/E1/J1) FRAMER/LIU COMBO
Local PCM
Highway
XRT86VL3x
1 of N-channels
Tx Serial
Clock
Tx Serial
Data In
Rx Serial
Clock
Rx Serial
Data Out
PRBS
Generator &
Analyser
External Data
Link Controller
Tx Overhead In
Rx Overhead Out
2-Frame
Slip Buffer
Elastic Store
Tx Framer
2-F ram e
Slip Buffer
Elastic Store
Rx Framer
Perform ance
Monitor
HDLC/LAPD
Controllers
Tx LIU
Interface
LLB LB
Rx LIU
Interface
LIU &
Loopback
Control
TTIP
TRING
RTIP
RRING
8kHz sync
OSC
Back Plane
1.544-16.384 Mbit/s
Signaling &
Alarms
System (Terminal) Side
TxON
JTAG
DMA
Interface
Microprocessor
Interface
INT
Memory
D[7:0]
3
A [1 4:0]
μP
Select
4 ^WR
ALE_AS
RD
RDY_DTACK
Intel/Motorola µP
Configuration, Control &
Status Monitor
1:2 Turns Ratio
1:1 Turns Ratio
RxLOS
Line Side
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