Data Sheet
June 2002
TMXF28155 Supermapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
389
Agere Systems Inc.
17 TMUX Functional Description
(continued)
Clearing the signal degrade state requires the definition of two measurement windows, a monitoring block consist-
ing of a number of frames in TMUX_SFNSCLEAR[18:0] (
Table 131 on page 119
), and a measurement interval
consisting of a number of monitoring blocks in TMUX_SFBCLEAR[11:0] (
Table 131
). A block is determined good
when the number of bit errors is less than a threshold set in TMUX_SFLCLEAR[3:0] (
Table 131
).
Signal degrade is cleared when a number of good monitoring blocks equals or exceeds the threshold in
TMUX_SFMCLEAR[7:0] (
Table 131
) for the measurement interval.
The set parameters are used when the signal fail state is clear, and the clear parameters are used when the signal
fail state is declared.
The signal degrade state may be forced to the declared state with TMUX_SFSET (
Table 88 on page 79
) and
forced to the cleared state with TMUX_SFCLEAR (
Table 88
). One shot signal must be provided to force the BER
algorithm into the failed state or normal state, respectively.
The above algorithm can detect bit error rates from 1 x 10
–3
to 1 x 10
–9
.
Table 539. Signal Fail Parameters
Note:
The thresholds written by the control system will be one less than the desired number, except for the
TMUX_SFLSET[3:0] and TMUX_SFLCLEAR[3:0] parameters.
Name
Function
TMUX_SFNSSET[18:0] (
Table 131 on page 119
)
Signal Fail Ns Set.
Number of frames in a monitoring block
for SF.
Signal Fail L Set.
Error threshold for determining if a monitor-
ing block is bad.
Signal Fail M Set.
Threshold of the number of bad monitoring
blocks in an observation interval. If the number of bad blocks
is below this threshold, then SF is cleared.
Signal Fail B Set.
Number of monitoring blocks.
Signal Fail Ns Clear.
Number of frames in a monitoring block
for SF.
Signal Fail L Clear.
Error threshold for determining if a moni-
toring block is bad.
Signal Fail M Clear.
Threshold of the number of bad monitor-
ing blocks in an observation interval. If the number of bad
blocks is below this threshold, then SF is cleared.
Signal Fail B Clear.
Number of monitoring blocks.
Signal Fail B1/B2 Error Count Select.
Control bit, when set
to a logic 0, causes the signal fail bit error rate algorithm to
use B1 errors; when set to a logic 1, causes the signal fail bit
error rate algorithm to use B2 errors.
Signal Fail Set.
Allows the signal degrade algorithm to be
forced into the failed state (active 0 to 1).
Signal Fail Clear.
Allows the signal degrade algorithm to be
forced into the normal state (active 0 to 1).
Signal Fail BER Algorithm State Bit.
Signal Fail BER Algorithm Delta Bit.
Signal Fail BER Algorithm Mask Bit.
TMUX_SFLSET[3:0] (
Table 131
)
TMUX_SFMSET[7:0] (
Table 131
)
TMUX_SFBSET[15:0] (
Table 131
)
TMUX_SFNSCLEAR[18:0] (
Table 131
)
TMUX_SFLCLEAR[3:0] (
Table 131
)
TMUX_SFMCLEAR[7:0] (
Table 131
)
TMUX_SFBCLEAR[15:0] (
Table 131
)
TMUX_SFB1B2SEL (
Table 105 on page 97
)
TMUX_SFSET (
Table 88 on page 79
)
TMUX_SFCLEAR (
Table 88
)
TMUX_RHSSF (
Table 101 on page 94
)
TMUX_RHSSFD (
Table 92 on page 81
)
TMUX_RHSSFM (
Table 96 on page 90
)