PM7346 datasheet(81/419 Pages) PMC

81 / 419 page

PM7346 S/UNI-QJET

DATASHEET

PMC-960835

ISSUE 6

SATURN QUAD USER NETWORK INTERFACE FOR J2, E3, T3

PMC-SIERRA, INC. PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA INC., AND ITS CUSTOMERS’ INTERNAL USE 60

The E3-FRMR declares out of frame alignment if the framing pattern is in error

for four consecutive frames. The E3-FRMR is an "off-line" framer, where all

frame alignment indications, all overhead bit indications, and all overhead bit

processing continue based on the previous alignment. Once the framer has

determined the new frame alignment, the out-of-frame indication is removed and

a COFA indication is declared if the new alignment differs from the previous

alignment.

The E3-FRMR detects the presence of AIS in the incoming data stream when

less than 8 zeros in a frame are detected while the framer is OOF in G.832

mode, or when less than 5 zeros in a frame are detected while OOF in G.751

mode. This algorithm provides a probability of detecting AIS in the presence of a

10-3 BER as 92.9% in G.832 and 98.0% in G.751.

Loss of signal is LOS is declared when no marks have been received for 32

consecutive bit periods. Loss of signal is de-asserted after 32 bit periods during

which there is no sequence of four consecutive zeros.

E3 Loss of Frame detection is provided as recommended by ITU-T G.783 with

programmable integration periods of 1ms, 2ms, or 3ms. While integrating up to

assert LOF, the counter will integrate up when the framer asserts an Out of

Frame condition and integrates down when the framer de-asserts the Out of

Frame 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.

9.3

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 125µs long, consisting of 96

bytes of payload, 2 reserved bytes, and 5 F-bits. The frames are grouped into 4-

frame multiframes. The multiframe format is as follows:

PM7346 Datasheet(PDF) 81 Page - PMC-Sierra, Inc