
QuadFALC
TM
PEF 22554 E
Functional Description T1/J1
Data Sheet
188
Rev. 1.2, 2006-01-26
reported by bit FRS0.LMFA. The state of terminal framing is not influenced. Now, the resynchronization
procedure includes only the search for multiframe alignment. Multiframe synchronization has been regained
after two consecutive correct multiframe patterns have been received.
5.4.6
Extended Superframe (F24 or ESF Format, T1/J1)
The use of the first bit of each frame for the multiframe alignment word (FAS) , the data link bits (DL), and the CRC
5.4.6.1
Synchronization Procedures (T1/J1)
For multiframe synchronization the FAS-bits are observed. Synchronous state is reached if at least one framing
candidate is definitely found, or the synchronizer is forced to lock onto the next available candidate (FMR0.FRS).
In the synchronous state the framing bits (FAS-bits) are observed. The following conditions selected by the register
bits FMR4.SSC(1:0) (FMR4_T) lead to the asynchronous state:
Two errors within 4/5/6 framing bits
Two or more erroneous framing bits within one ESF multiframe
More than 320 CRC6 errors per second interval (FMR5.SSC2)
4 incorrect (1 out of 6) consecutive multiframes independent of CRC6 errors. There are four multiframe
synchronization modes selectable using FMR2.MCSP and FMR2.SSP.
FMR2.MCSP/SSP = 00
b: In the synchronous state, the setting of FMR0.FRS or FMR0.EXLS resets the
synchronizer and initiates a new frame search. The synchronous state is reached again, if there is only one
definite framing candidate. In the case of repeated apparent simulated candidates, the synchronizer remains
in the asynchronous state. In asynchronous state, setting bit FMR0.FRS induces the synchronizer to lock onto
Table 56
Extended Superframe Structure (F24, ESF; T1/J1)
Multiframe
Frame Number
F-Bits
Signaling Channel
Designation
Multiframe Bit
Number
Assignments
FAS
DL
CRC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
0
193
386
579
772
965
1158
1351
1544
1737
1930
2123
2316
2509
2702
2895
3088
3231
3474
3667
3860
4053
4246
4439
–
0
–
0
–
1
–
0
–
1
–
1
m
–
m
–
m
–
m
–
m
–
m
–
m
–
m
–
m
–
m
–
m
–
m
–
e1
–
e2
–
e3
–
e4
–
e5
–
e6
–
A
B
C
D