TMXF28155 Supermapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Data Sheet
June 2002
424
Agere Systems Inc.
18 SPE Mapper Functional Description
(continued)
Table 558. Signal Fail Parameters
Note: The threshold written by the control system is one less than the desired number, except for the SPE_SFLSET[3:0]/SFLCLEAR[3:0]
parameter.
18.14.13 POAC Drop
The SPE mapper accommodates one path overhead access channel (POAC output channel).
The POAC channel consists of the following signals:
I
A 576 kHz inverted clock signal sourced by the TMUX (RPOACCLK, pin AE3).
I
A 576 kbits/s data signal sourced by the TMUX (RPOACDATA, pin AD4).
I
An 8 kHz synchronization signal, sourced by the TMUX (RPOACSYNC, pin AF4). The sync signal is normally
low; during the last clock period of each frame coincident with the least significant bit of the last byte, the sync
signal is high.
The data signal is partitioned into frames of 9 bytes. The frame repetition rate is 8 kHz. Each byte consists of 8 bits
that are transmitted/received most significant bit first (MSB). The MSB of the second byte of each frame contains
an odd/even parity bit over the 72 bits of the previous frame. The remaining 7 bits of this byte are not specified.
Name
Function
SPE_SFNSSET[18:0] (
Table 169 on page 150
)
Signal Fail Ns Set.
Number of frames in a monitoring block for
SF.
SPE_SFLSET[3:0] (
Table 169
)
Signal Fail L Set.
Error threshold for determining if a monitoring
block is bad.
SPE_SFMSET[7:0] (
Table 169
)
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.
SPE_SFBSET[15:0] (
Table 169
)
Signal Fail B Set.
Number of monitoring blocks.
SPE_SFNSCLEAR[18:0] (
Table 169
)
Signal Fail Ns Clear.
Number of frames in a monitoring block
for SF.
SPE_SFLCLEAR[3:0] (
Table 169
)
Signal Fail L Clear.
Error threshold for determining if a monitor-
ing block is bad.
SPE_SFMCLEAR[7:0] (
Table 169
)
Signal Fail 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 SF is cleared.
SPE_SFBCLEAR[15:0] (
Table 169
)
Signal Fail B Clear.
Number of monitoring blocks.
SPE_SFSET (
Table 155 on page 136
)
Signal Fail Set.
Allows the signal degrade algorithm to be
forced into the failed state (active 0 to 1).
SPE_SFCLEAR (
Table 155
)
Signal Fail Clear.
Allows the signal degrade algorithm to be
forced into the normal state (active 0 to 1).
SPE_SFB3 (
Table 158 on page 140
)
Signal Fail BER Algorithm State Bit.
SPE_SFB3D (
Table 156 on page 136
)
Signal Fail BER Algorithm Delta Bit.
SPE_SFB3M (
Table 157 on page 138
)
Signal Fail BER Algorithm Mask Bit.