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Data Sheet
193
Rev. 1.2, 2006-01-26
QuadFALC
TM
PEF 22554 E
Functional Description T1/J1
5.5.1.1
Severely Errored Frame Indication SEF (T1/J1)
An SEF interrupt statusbit ISR7.SEFEI (ISR7_T) and an appropriate mask register bit IMR7.SEFEI is provided,
which shows if severely errored frames (SEF) were detected according to ANSI-T1.231 chapter 6.1.2.2.2.
An SEF defect is determined by examining contiguous time windows for frame bit errors. For SF the window size
is 0.75 ms, and only the F
T bits are examined. For ESF the window size is 3 ms, and only the frame pattern
sequence (FPS) bits are examined.
Table 59
Summary of Alarm Detection and Release (T1/J1)
Alarm
Detection Condition
Clear Condition
Red Alarm or
Loss-Of-Signal
(LOS)
No transitions (logical zeros) in a
programmable time interval of 16 to 4096
consecutive pulse periods. Programmable
receive input signal threshold
Programmable number of ones (1 to 256) in
a programmable time interval of 16 to 4096
consecutive pulse periods. A one is a signal
with a level above the programmed
threshold.
or
the pulse-density is fulfilled and no more
than 15 contiguous zeros during the
recovery interval are detected.
Blue Alarm or
Alarm Indication
Signal (AIS)
FMR4.AIS3 = 0:
Less than 3 zeros in 12 frames or 24
frames (ESF),
FMR4.AIS3 = 1:
Less than 4 zeros in 12 frames or less than
6 zeros in 24 frames (ESF)
Active for at least one multiframe.
FMR4.AIS3 = 0:
More than 2 zeros in 12 or 24 frames (ESF),
FMR4.AIS3 = 1:
More than 3 zeros in 12 frames or more than
5 zeros in 24 frames (ESF)
Yellow Alarm or
Remote Alarm
(RRA)
1)
1) RRA detection operates in the presence of 10
3 bit error rate.
RC1.RRAM = 0:
Bit 2 = 0 in 255 consecutive time slots or
FS-bit = 1 of frame12 in F12 (D4) format or
8 x 1, 8 x 0 in the DL channel (ESF)
RC1.RRAM = 1:
Bit 2 = 0 in every time slot per frame or FS-
bit = 1 of frame12 in F12 (D4) format or
8 x 1, 8 x 0 in the DL channel (ESF)
RC1.RRAM = 0:
Set conditions no longer detected.
RC1.RRAM = 1:
Bit 2 = 0 not detected in 3 consecutive
frames or
FS-bit not detected in 3 consecutive
multiframes or
8 x 1, 8 x 0 not detected for 3 times in a row
(ESF).
Severely Errored
Frames (SEF)
Indication
Two or more frame bit errors in the timing
window are detected.
Signal is in-frame and there are less than
two frame bit errors in the timing window
Excessive Zeros
(EXZD)
More than 7 (B8ZS code) or more than 15
(AMI code) contiguous zeros
Latched Status: cleared on read
Pulse-Density
Violation
(PDEN)
Less than N ones in each and every time
window of 8 x(N+1) time slots with N taking
all values of 1 to 23
or
more than 15 consecutive zeros
Latched Status: cleared on read
Transmit Line Short
(XLS)
More than 3 pulse periods with highly
increased transmit line current on XL1/2
Transmit line current limiter inactive
Transmit Ones-
Density
(XLO)
32 consecutive zeros in the transmit data
stream on XL1/2
Cleared with each transmitted pulse