TMXF28155/51 Super Mapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Preliminary Data Sheet
May 2001
382
Agere Systems Inc.
17 TMUX Functional Description
(continued)
Table 526. 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 91
) and change of state
indication is reported in register bit, TMUX_RHSSFD (
Table 82, starting on page79
), with the interrupt mask bit,
TMUX_RHSSFM (
Table 86 on page88
). This bit error rate algorithm can operate on either B1 or B2 errors
selected with register bit, TMUX_SDB1B2SEL (
Table 95 on pag e95
). Each B3 monitor has its own bit error rate
algorithm as well with the failure indicated in TMUX_RSFB3[1
—
3] (
Table 92 on pag e92
).
Declaring the signal degrade state requires the definition of two measurement windows, a monitoring block consist-
ing of a number of frames in TMUX_SFNSSET[18:0] (
Table 121 on page117
) and a measurement interval consist-
ing of a number of monitoring blocks in TMUX_SFBSET[11:0] (
Table 121
). A block is determined bad when the
number of bit errors equals or exceeds a threshold set in TMUX_SFLSET[3:0] (
Table 121
). Signal degrade is
declared when a number of bad monitoring blocks equals or exceeds the threshold in TMUX_SFMSET[7:0]
(
Table 121
) for the measurement interval.
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 121
) and a measurement interval consisting of a
number of monitoring blocks in TMUX_SFBCLEAR[11:0] (
Table 121
). A block is determined good when the num-
ber of bit errors is less than a threshold set in TMUX_SFLCLEAR[3:0] (
Table 121
).
Name
Function
TMUX_SDNSSET[18:0] (
Table 120
)
TMUX_SDLSET[3:0] (
Table 120
)
Signal Degrade Ns Set.
Number of frames in a monitoring block for SD.
Signal Degrade L Set.
Error threshold for determining if a monitoring
block is bad.
Signal Degrade M Set.
Threshold of the number of bad monitoring blocks
in an observation interval. If the number of bad blocks is below this thresh-
old, then SD is cleared.
Signal Degrade B Set.
Number of monitoring blocks in a measurement
interval.
Signal Degrade Ns Clear.
Number of frames in a monitoring block for
SD.
Signal Degrade L Clear.
Error threshold for determining if a monitoring
block is bad.
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_SDMSET[7:0] (
Table 120
)
TMUX_SDBSET[15:0] (
Table 120
)
TMUX_SDNSCLEAR[18:0]
(
Table 120
)
TMUX_SDLCLEAR[3:0] (
Table 120
)
TMUX_SDMCLEAR[7:0] (
Table 120
)
TMUX_SDBCLEAR[15:0] (
Table 120
)
Signal Degrade B Clear.
Number of monitoring blocks in a measurement
interval.
TMUX_SDSET (
Table 78
)
Signal Degrade Set.
Allows the signal degrade algorithm to be forced
into the failed state (active 0 to 1).
TMUX_SDCLEAR (
Table 78
)
Signal Degrade Clear.
Allows the signal degrade algorithm to be forced
into the normal state (active 0 to 1).
TMUX_SDB1B2SEL (
Table 95
)
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; oth-
erwise, B2 errors are used to calculate the error rate.
TMUX_RHSSD (
Table 91
)
Signal Degrade BER Algorithm State Bit.
TMUX_RHSSDD (
Table 82
)
Signal Degrade BER Algorithm Delta Bit.
TMUX_RHSSDM (
Table 86
)
Signal Degrade BER Algorithm Mask Bit.