XRT86SH328_3 Datasheet, PDF (1/119 Pages) Exar Corporation – VOYAGER - T1 FRAMER + LIU REGISTER DESCRIPTION

XRT86SH328
VOYAGER - T1 FRAMER + LIU REGISTER DESCRIPTION
AUGUST 2008
REV. 1.0.1
GENERAL DESCRIPTION
The XRT86SH328 has a total of 56 independent T1
framers (or 42 independent framers for E1). This
Voyager Device maps 28 T1 payloads up to STS-3/
STM-1. The purpose of the 56 framers is to allow
back-to-back transmit and receive framers on each of
the 28 channel Egress and Ingress data paths. The
channel numbering system references the framers
according to the block diagram shown in Figure 1.
The XRT86SH328 provides T1 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 T1 signal formats.
Each Framer block contains its own Transmit and
Receive T1 Framing function. There is 1 Transmit
HDLC controller per channel which encapsulates
contents of the Transmit HDLC buffers into LAPD
Message frames. There is 1 Receive HDLC controller
per channel which extracts the payload content of
Receive LAPD Message frames from the incoming
T1 data stream and write the contents into the
Receive HDLC buffers.
The XRT86SH328 fully meets all of the latest T1
specifications: ANSI E1.107-1988, ANSI E1.403-
1995, ANSI E1.231-1993, ANSI 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. XRT86SH328 21-CHANNEL T1 FRAMERS (56 TOTAL T1 FRAMERS)
T1 Framers
Ch 0
Ch 28
Rx
Tx
Tx
Rx
Rx
Tx
Tx
Rx
Rx
Tx
Tx
Rx
Rx
Tx
VT
Mapper
Cross
Connect
Tx
Rx
LIU
Ch 27
Rx
Tx
Ch 55
Tx
Rx
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