S/UNI®-JET Data Sheet
Released
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
2
3
4
1-8
.. 761-768
769-776
777-784
785 786
787 788
789
TS1[1:8]
TS1[1:8]
TS1[1:8]
TS1[1:8]
.. TS96[1:8]
.. TS96[1:8]
.. TS96[1:8]
.. TS96[1:8]
TS97[1:8]
TS97[1:8]
TS97[1:8]
TS97[1:8]
TS98[1:8]
TS98[1:8]
TS98[1:8]
TS98[1:8]
1
1
0
0
m
0
m
e5
1
0
1
0
x1
e1
x2
e2
x3
e3
a
e4
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
5
4
2
check sequence, should have a remainder of 0 when divided by x + x + x + 1.
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
58
PMC [ PMC-SIERRA, INC ]
