MT9074 Datasheet, PDF (32/122 Pages) Mitel Networks Corporation – T1/E1/J1 Single Chip Transceiver

MT9074
Advance Information
Out of synchronization
>914 CRC errors
in one second
YES
NO
Search for primary basic frame
alignment signal RAI=1, Es=0.
YES
NO
Verify Bit 2 of non-frame
alignment signal.
3 consecutive
incorrect frame
alignment
signals
YES
No CRC
multiframe alignment.
8 msec. timer expired*
Verify second occurrence of
frame alignment signal.
YES
CRC-4 multi-frame alignment
Primary basic frame synchronization
acquired. Enable traffic RAI=0, E’s=0. Start
loss of primary basic frame alignment
checking. Notes 7 & 8.
Start 400 msec timer.
Note 7.
NO
Signalling multi-frame alignment
Search for multiframe
alignment signal.
Note 7.
NO
Start 8 msec timer.
Note 7.
RAI = 0
Basic frame
NO
alignment acquired
Multiframe synchronization
acquired as per G.732.
Note 7.
YES
Find two CRC frame
alignment signals.
Note 7.
No CRC
multiframe
alignment.
8 msec
Check for two consecutive errored
multiframe alignment signals.
Notes 7 & 8.
CRC multiframe
alignment
Parallel search for new basic frame
RAI = 1 alignment signal.
Notes 6 & 7.
CRC-to-CRC interworking. Re-align to new basic
frame alignment. Start CRC-4 processing. E-bits set
as per G.704 and I.431. Indicate CRC synchronization
achieved.
Notes 7& 8.
only if CRC-4 synchronization is selected and automatic CRC-4
interworking is de-selected
400 msec timer expired
CRC-to-non-CRC interworking. Maintain primary
basic frame alignment. Continue to send CRC-4
data, but stop CRC processing. E-bits set to ‘0’.
Indicate CRC-to-non-CRC operation. Note 7.
* only if CRC-4 synchronization is selected and automatic CRC-4
interworking is de-selected.
** only if automatic CRC-4 interworking is selected.
YES
Figure 15 - Synchronization State Diagram
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