Preliminary Data Sheet
May 2001
TMXF28155/51 Super Mapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
381
Agere Systems Inc.
17 TMUX Functional Description
(continued)
Any change to F3 byte monitor registers is reported in TMUX_RF3MOND[1
—
3] (
Table 83
), with interrupt mask bits,
TMUX_RF3MONM[1
—
3] (
Table 87 on page89
).
The TMUX also maintains a history of the previous valid F3 byte in TMUX_F3MON1[1
—
3][7:0] (
Table 104 on
page 101
). 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) are stored in
TMUX_K3MON[1
—
3][7:0] (
Table 104
). Each register will be updated after a number determined by the value in
TMUX_CNTDK3[3:0] (
Table 99 on page99
) of consecutive frames of identical K3[7:0] for that particular
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 83
), with interrupt mask bits,
TMUX_RK3MONM[1
—
3] (
Table 87 on page89
). 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) are stored in
TMUX_N1MON[1
—
3][7:0] (
Table 104 on page101
). Each register will be updated after a number determined by
the value in TMUX_CNTDN1[3:0] (
Table 99 on page 99
) of consecutive frames of identical N1[7:0] for that particu-
lar STS-1/STM-1. That is, the 8-bit pattern must be identical for a number of frames prior to updating the N1 regis-
ter. Any change to N1 monitor registers will be reported in TMUX_RN1MOND[1
—
3] (
Table 83
), with interrupt mask
bits, TMUX_RN1MONM[1
—
3] (
Table 87 on page89
). 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 91 on page 92
) and
change of state indication is reported in register bit, TMUX_RHSSDD (
Table 82, starting on page79
), with the
interrupt mask bit, TMUX_RHSSDM (
Table 87 on page 89
). This bit error rate algorithm can operate on either B1 or
B2 errors, determined by the value of TMUX_SDB1B2SEL (
Table 95 on page95
). Each B3 monitor has an inde-
pendent signal degrade function as well in TMUX_RSDB3[1
—
3] (
Table 92 on page92
).
Declaring the signal degrade state requires the definition of two measurement windows, a monitoring block consist-
ing of a number of frames in TMUX_SDNSSET[18:0] (
Table 120 on page116
) and a measurement interval consist-
ing of a number of monitoring blocks in TMUX_SDBSET[11:0] (
Table 120
). A block is determined bad when the
number of bit errors equals or exceeds a threshold set in TMUX_SDLSET[3:0] (
Table 120
). Signal degrade is
declared when a number of bad monitoring blocks equals or exceeds the threshold in TMUX_SDMSET[7:0]
(
Table 526
) 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 120
) and a measurement interval consisting of a
number of monitoring blocks in TMUX_SDBCLEAR[11:0] (
Table 120
). A block is determined good when the num-
ber of bit errors is less than a threshold set in TMUX_SDLCLEAR[3:0] (
Table 120
). Signal degrade is cleared when
a number of good monitoring blocks equals or exceeds the threshold in TMUX_SDMCLEAR[7:0] (
Table 120
) 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 78 on page 77
) and forced
to the cleared state with TMUX_SDCLEAR (
Table 78
). One shot signal must be provided to force the BER algo-
rithm 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
.