TMXF28155 Supermapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Data Sheet
June 2002
390
Agere Systems Inc.
17 TMUX Functional Description
(continued)
Path Overhead Access Channel (POAC) Drop.
The TMUX provides one path overhead access channel (POAC
output channel). The TMUX can receive up to three STS-1 signals. There are two register bits,
TMUX_RPOAC_SEL[1:0] (
Table 128 on page 117
), to designate which STS-1s POH will be dropped onto the
POAC channel. TMUX_RPOAC_SEL[1:0] = 01 designates STS-1 #1, TMUX_RPOAC_SEL[1:0] = 10 designates
STS-1 #2, and TMUX_RPOAC_SEL[1:0] = 11 designates STS-1 #3. TMUX_RPOAC_SEL[1:0] = 00 designates
that the RPOAC channel is not driven by the TMUX.
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. 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 541
summarize the access capabilities of the receive POAC.
Table 541. Path Overhead Byte Access
Even or odd parity can be inserted into the first bit of the MSB byte of the POAC outgoing frame. Parity is selected
with TMUX_RPOAC_OEPINS (
Table 128 on page 117
).
AIS-P Insertion and AUTO_AISO Generation.
Upon detecting certain failure conditions, the TMUX asserts the
external output signals named AUTO_AIS[1—3] (pins AD6, AE6, and AC6). The AUTO_AIS[1—3] signals, one per
STS-1, also informs the other blocks within the Supermapper to insert AIS downstream due to detected failures.
The following conditions can cause AUTO_AISO[1—3] signals to be asserted: line AIS, LOC (STS-1 mode only),
LOS, LOF, OOF, LOP-P, SF (B1, B2, or B3), SD (B1, B2, or B3), payload label mismatch, or payload unequipped.
Each condition can be individually inhibited from contributing to the internal AUTO_AISO[1—3] signals. For concat-
enated signals (STS-3c or STM-1), all AUTO_AISO[1—3] signals should be driven coincidentally. In STS-3 mode,
each STS-1 signal has a corresponding AUTO_AISO signal.
Table 540. Signal Fail or Signal Degrade Recommended Programming Values
Set
Threshold
1x10
–3
1x10
–4
1x10
–5
1x10
–6
1x10
–7
1x10
–8
1x10
–9
NsSet
LSet
MSet
BSet
Clear
Threshold
1x10
–4
1x10
–5
1x10
–6
1x10
–7
1x10
–8
1x10
–9
1x10
–10
NsClear
LClear
MClear
BClear
0x00001
0x00006
0x00030
0x001E0
0x01275
0x0B5A4
0x3F7A0
0x5
0x8
0x6
0x6
0x6
0x6
0x4
0x3D
0x03
0x03
0x03
0x04
0x04
0x05
0x003D
0x0007
0x0007
0x0007
0x0009
0x0009
0x0013
0x00001
0x00006
0x00030
0x001E0
0x01275
0x0B5A4
0x3F7A0
0x6
0x2
0x2
0x2
0x2
0x2
0x2
0x03
0x03
0x03
0x03
0x04
0x03
0x02
0x0007
0x0007
0x0007
0x0007
0x0009
0x0009
0x000F
J1
POH Parity
C2
G1
F2
H4
F3
K3
N1