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QuadFALC
TM
PEF 22554 E
Functional Description T1/J1
Data Sheet
192
Rev. 1.2, 2006-01-26
5.5
Additional Receive Framer Functions (T1/J1)
The additional framer functions are described in the following chapters:
5.5.1
Error Performance Monitoring and Alarm Handling (T1/J1)
Alarm Indication Signal: Detection and recovery is flagged by bit FRS0.AIS and ISR2.AIS. Transmission is
enabled by bit FMR1.XAIS.
Loss-Of-Signal: Detection and recovery is flagged by bit FRS0.LOS and ISR2.LOS.
Remote Alarm Indication: Detection and release is flagged by bit FRS0.RRA and ISR2.RA/RAR. Transmission
is enabled by bit FMR4.XRA. The automatic transmit remote alarm feature in case of LFA can be enabled by
setting FMR2.AXRA.
Excessive Zeros: Detection is flagged by bit FRS1.EXZD.
Pulse-Density Violation: Detection is flagged by bit FRS1.PDEN and ISR0.PDEN.
Transmit Line Shorted: Detection and release is flagged by bit FRS1.XLS and ISR1.XLSC, see also
Transmit Ones-Density: Detection and release is flagged by bit FRS1.XLO and ISR1.XLSC.
F12 (D4)
and
F72 (SLC96)
FMR2.SSP = 0:
Combined FT + FS framing search: First
searching for FT pattern with optional forcing
on next available framing candidates and then
for 2 consecutive correct FS pattern
1).
FMR2.SSP = 1:
Separated FT + FS pattern search: Loss of FT
framing starts first search for FT and then for 2
consecutive correct FS pattern1). Loss of FS
framing starts only the FS pattern1) search.
FMR2.SSP = 0: 2 out of 4/5/6 incorrect
FT- or FS-bits
FMR2.SSP = 1:
2 out of 4/5/6 incorrect FT-bits searched in
FT and FS framing bits,
2 out of 4/5/6 incorrect FS-bits searched
only the FS framing.
F24 (ESF)
FMR2.MCSP/SSP = 00
B:
Only one FAS pattern found, optional forcing
on next available FAS framing candidate with
discarding of all remaining framing candidates.
FMR2.MCSP/SSP = 01
B:
3 consecutive correct multiframing found
independent of CRC6 errors.
FMR2.MCSP/SSP = 10
B:
Choosing multiple framing pattern step by step,
optional forcing on next available FAS framing
pattern with discarding only of the previous
assumed framing candidate.
FMR2.MCSP/SSP = 11
B:
FAS framing correctly found and CRC6 check
error free.
2 out of 4/5 incorrect FAS-bits
or
2 out of 6 incorrect FAS-bits per multiframe
or
4 consecutive incorrect multiframing
pattern
or
more than 320 CRC6 errors per second
interval
1) In F12 (D4) format bit 1 in frame 12 is excluded from the synchronization process.
Table 58
Summary Frame Recover/Out of Frame Conditions (T1/J1) (cont’d)
Format
Frame Recover Condition
Out of Frame Condition