TMXF28155 Supermapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Data Sheet
June 2002
388
Agere Systems Inc.
17 TMUX Functional Description
(continued)
Table 538. Signal Degrade (SD) Parameters
Note:
The thresholds written by the control system will be one less than the desired number, except for the
TMUX_SDLSET[3:0] and TMUX_SDLCLEAR[3:0] parameters.
Signal Fail BER Algorithm.
A signal degrade state in register bit TMUX_RHSSF (
Table 101
) and change of state
indication is reported in register bit TMUX_RHSSFD (
Table 92, starting on page 81
), with the interrupt mask bit,
TMUX_RHSSFM (
Table 96 on page 90
). This bit error rate algorithm can operate on either B1 or B2 errors
selected with register bit TMUX_SDB1B2SEL (
Table 105 on page 97
). Each B3 monitor has its own bit error rate
algorithm as well as the failure indicated in TMUX_RSFB3[1—3] (
Table 102 on page 94
).
Declaring the signal degrade state requires the definition of two measurement windows, a monitoring block con-
sisting of a number of frames in TMUX_SFNSSET[18:0] (
Table 131 on page 119
), and a measurement interval
consisting of a number of monitoring blocks in TMUX_SFBSET[11:0] (
Table 131
). A block is determined bad when
the number of bit errors equals or exceeds a threshold set in TMUX_SFLSET[3:0] (
Table 131
). Signal degrade is
declared when a number of bad monitoring blocks equals or exceeds the threshold in TMUX_SFMSET[7:0]
(
Table 131
) for the measurement interval.
Name
Function
TMUX_SDNSSET[18:0] (
Table 130 on page 118
)
Signal Degrade Ns Set.
Number of frames in a monitoring
block for SD.
TMUX_SDLSET[3:0] (
Table 130
)
Signal Degrade L Set.
Error threshold for determining if a
monitoring block is bad.
TMUX_SDMSET[7:0] (
Table 130
)
Signal Degrade M Set.
Threshold of the number of bad moni-
toring blocks in an observation interval. If the number of bad
blocks is below this threshold, then SD is cleared.
TMUX_SDBSET[15:0] (
Table 130
)
Signal Degrade B Set.
Number of monitoring blocks in a
measurement interval.
TMUX_SDNSCLEAR[18:0] (
Table 130
)
Signal Degrade Ns Clear.
Number of frames in a monitoring
block for SD.
TMUX_SDLCLEAR[3:0] (
Table 130
)
Signal Degrade L Clear.
Error threshold for determining if a
monitoring block is bad.
TMUX_SDMCLEAR[7:0] (
Table 130
)
Signal Degrade M Clear.
Threshold of the number of bad
monitoring blocks in an observation interval. If the number of
bad blocks is below this threshold, then SD is cleared.
TMUX_SDBCLEAR[15:0] (
Table 130
)
Signal Degrade B Clear.
Number of monitoring blocks in a
measurement interval.
TMUX_SDSET (
Table 88 on page 79
)
Signal Degrade Set.
Allows the signal degrade algorithm to
be forced into the failed state (active 0 to 1).
TMUX_SDCLEAR (
Table 88
)
Signal Degrade Clear.
Allows the signal degrade algorithm to
be forced into the normal state (active 0 to 1).
TMUX_SDB1B2SEL (
Table 105 on page 97
)
Signal Degrade 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; otherwise, B2 errors are used to calculate the
error rate.
TMUX_RHSSD (
Table 101 on page 94
)
Signal Degrade BER Algorithm State Bit.
TMUX_RHSSDD (
Table 92 on page 81
)
Signal Degrade BER Algorithm Delta Bit.
TMUX_RHSSDM (
Table 96 on page 90
)
Signal Degrade BER Algorithm Mask Bit.