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S/UNI-JET Data Sheet
Released
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
58
E3 LOF detection is provided as recommended by ITU-T G.783 with programmable integration
periods of 1 ms, 2 ms, or 3 ms. While integrating up to assert LOF, the counter will integrate up
when the framer asserts an OOF condition and integrates down when the framer de-asserts the
OOF condition. Once an LOF is asserted, the framer must not assert OOF for the entire
integration period before LOF is de-asserted.
The E3-FRMR can also be enabled to automatically assert the RAI/FERF indication in the
outgoing transmit stream upon detection of any combination of LOS, OOF or AIS. The
E3-FRMR can also be enabled to automatically insert G.832 FEBE upon detection of receive
BIP-8 errors.
10.3
J2 Framer
The J2-FRMR integrates circuitry to decode a unipolar or B8ZS encoded signal and frame to the
resulting 6312 kbps J2 bit stream. Having found frame, the J2-FRMR extracts a variety of
overhead and datalink information from the J2 bit stream.
The J2 format consists of 789-bit frames, each 125 μs long, consisting of 96 bytes of payload, 2
reserved bytes, and five F-bits. The frames are grouped into 4-frame multiframes. The multiframe
format is described in Table 4.
Table 4 Multiframe Format
Bit
#
1-8
..
761-768
769-776
777-784
785
786
787
788
789
1
TS1[1:8]
..
TS96[1:8]
TS97[1:8]
TS98[1:8]
1
1
0
0
m
2
TS1[1:8]
..
TS96[1:8]
TS97[1:8]
TS98[1:8]
1
0
1
0
0
3
TS1[1:8]
..
TS96[1:8]
TS97[1:8]
TS98[1:8]
x1
x2
x3
a
m
4
TS1[1:8]
..
TS96[1:8]
TS97[1:8]
TS98[1:8]
e1
e2
e3
e4
e5
Notes
1.
TS1
.
TS96
are the byte interleaved payloads.
8.
TS97
,
TS98
are reserved channels for signaling.
9. The Frame Alignment Signal is represented as binary ones and zeroes.
10.
m
is a 4-kHz datalink.
11.
x1
,
x2
, and
x3
are spare bits, usually logic one.
12.
a
is the remote LOF alarm bit, active high.
13.
e1
.
e5
represent the CRC-5 check sequence. The entire 3156-bit multiframe, including the CRC-5
check sequence, should have a remainder of 0 when divided by x5 + x4 + x2 + 1.