TMXF28155/51 Super Mapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Preliminary Data Sheet
May 2001
418
Agere Systems Inc.
18 SPE Mapper Functional Description
(continued)
Table 546. 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.
Bytes shown in
Table 547
summarize the access capabilities of the receive POAC.
Name
Function
SPE_SFNSSET[18:0] (
Table 159
)
SPE_SFLSET[3:0] (
Table 159
)
Signal Fail Ns Set.
Number of frames in a monitoring block for SF.
Signal Fail L Set.
Error threshold for determining if a monitoring block is
bad.
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 thresh-
old, then SF is cleared.
Signal Fail B Set.
Number of monitoring blocks.
SPE_SFMSET[7:0] (
Table 159
)
SPE_SFBSET[15:0] (
Table 159
)
SPE_SFNSCLEAR[18:0] (
Table 159
)
Signal Fail Ns Clear.
Number of frames in a monitoring block for SF.
SPE_SFLCLEAR[3:0] (
Table 159
)
Signal Fail L Clear.
Error threshold for determining if a monitoring block
is bad.
SPE_SFMCLEAR[7:0] (
Table 159
)
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 thresh-
old, then SF is cleared.
SPE_SFBCLEAR[15:0] (
Table 159
)
Signal Fail B Clear.
Number of monitoring blocks.
SPE_SFSET (
Table 145
)
Signal Fail Set.
Allows the signal degrade algorithm to be forced into the
failed state (active 0 to 1).
SPE_SFCLEAR (
Table 145
)
Signal Fail Clear.
Allows the signal degrade algorithm to be forced into
the normal state (active 0 to 1).
SPE_SFB3 (
Table 148
)
Signal Fail BER Algorithm State Bit.
SPE_SFB3D (
Table 146
)
Signal Fail BER Algorithm Delta Bit.
SPE_SFB3M (
Table 147
)
Signal Fail BER Algorithm Mask Bit.