Data Sheet
June 2002
TMXF28155 Supermapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
387
Agere Systems Inc.
17 TMUX Functional Description
(continued)
Any change to F3 byte monitor registers is reported in TMUX_RF3MOND[1—3] (
Table 93 on page 83
) with inter-
rupt mask bits, TMUX_RF3MONM[1—3] (
Table 97 on page 91
).
The TMUX also maintains a history of the previous valid F3 byte in TMUX_F3MON1[1—3][7:0] (
Table 114 on
page 103
). The continuous N-times detection counter(s) will be reset to 0 upon the transition of the framer into the
out of frame state.
K3 Byte Monitor.
The TMUX monitors the K3 byte for each STS-1/STM-1. The K3 byte(s) is stored in
TMUX_K3MON[1—3][7:0] (
Table 114 on page 103
). Each register will be updated after a number determined by
the value in TMUX_CNTDK3[3:0] (
Table 109 on page 101
) of consecutive frames of identical K3[7:0] for that par-
ticular
STS-1/STM-1. That is, the 8-bit pattern must be identical for a number of frames prior to updating the K3 register.
Any change to K3 monitor registers is reported in TMUX_RK3MOND[1—3] (
Table 93 on page 83
) with interrupt
mask bits, TMUX_RK3MONM[1—3] (
Table 97 on page 91
). The continuous N-times detection counter(s) will be
reset to 0 upon the transition of the framer into the out of frame state.
N1 Byte Monitor.
The TMUX monitors the N1 byte for each STS-1/STM-1. The N1 byte(s) is stored in
TMUX_N1MON[1—3][7:0] (
Table 114 on page 103
). Each register will be updated after a number determined by
the value in TMUX_CNTDN1[3:0] (
Table 109 on page 101
) of consecutive frames of identical N1[7:0] for that par-
ticular STS-1/STM-1. That is, the 8-bit pattern must be identical for a number of frames prior to updating the N1
register. Any change to N1 monitor registers will be reported in TMUX_RN1MOND[1—3] (
Table 93 on page 83
),
with interrupt mask bits, TMUX_RN1MONM[1—3] (
Table 97 on page 91
). The continuous N-times detection
counter(s) will be reset to 0 upon the transition of the framer into the out of frame state.
Signal Degrade BER Algorithm.
A signal degrade state in register bit TMUX_RHSSD (
Table 101 on page 94
)
and change of state indication is reported in register bit TMUX_RHSSDD (
Table 92, starting on page 81
), with the
interrupt mask bit, TMUX_RHSSDM (
Table 97 on page 91
). This bit error rate algorithm can operate on either B1
or B2 errors, determined by the value of TMUX_SDB1B2SEL (
Table 105 on page 97
). Each B3 monitor has an
independent signal degrade function as well in TMUX_RSDB3[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_SDNSSET[18:0] (
Table 130 on page 118
), and a measurement interval
consisting of a number of monitoring blocks in TMUX_SDBSET[11:0] (
Table 130
). A block is determined bad when
the number of bit errors equals or exceeds a threshold set in TMUX_SDLSET[3:0] (
Table 130
). Signal degrade is
declared when a number of bad monitoring blocks equals or exceeds the threshold in TMUX_SDMSET[7:0]
(
Table 538
) 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_SDNSCLEAR[18:0] (
Table 130
), and a measurement interval consisting of a
number of monitoring blocks in TMUX_SDBCLEAR[11:0] (
Table 130
). A block is determined good when the num-
ber of bit errors is less than a threshold set in TMUX_SDLCLEAR[3:0] (
Table 130
). Signal degrade is cleared when
a number of good monitoring blocks equals or exceeds the threshold in TMUX_SDMCLEAR[7:0] (
Table 130
) for
the measurement interval.
The set parameters are used when the signal degrade state is clear, and the clear parameters are used when the
signal degrade state is declared.
The signal degrade state may be forced to the declared state with TMUX_SDSET (
Table 88 on page 79
) and
forced to the cleared state with TMUX_SDCLEAR (
Table 88
). One shot signal must be provided to force the BER
algorithm into the failed state or normal state, respectively.
The algorithm described above can detect bit error rates from 1 x 10
–3
to 1 x 10
–9
.