![](http://datasheet.mmic.net.cn/330000/PM73121_datasheet_16444365/PM73121_49.png)
PM73121AAL1gator II
PMC-Sierra, Inc.
L
PMC-980620
,VVXH
AAL1 SAR Processor
Data Sheet
35235,(7$5<$1'&21),'(17,$/7230&6,(55$,1&$1')25,76&86720(56,17(51$/86(
and Figure 21 shows the contents of the transmit signaling buffer for the different signaling
modes.
3.1.1
Transmit Conditioning
The T_COND_DATA structure allows conditional data to be defined on a per-DS0 basis. The
structure T_COND_SIG allows conditioned signaling to be defined on a per-DS0 basis. The TX_
COND bit in the T_QUEUE_TBL allows the cell building logic (described in
section 3.3 “Trans-
mit Adaptation Layer Processor (TALP)” on page 38
) to be directed to build cells from the condi-
tioned data and signaling. The TX_COND bit can be set on a per-queue basis.
3.1.2
Transmit Signaling Freezing
Signaling freezing is a required function when transporting CAS. This function holds the signal-
ing unchanged when the incoming line fails. The PMC-Sierra framers provide this function. If a
framer is used that does not support signaling freezing, this function must be provided externally.
3.1.3
SRTS for the Transmit Side
NOTE: The AAL1gator II uses Bellcore’s patented SRTS clock recovery technique. Refer to
the NOTE on
page 172
for additional information regarding Bellcore’s SRTS patent.
Figure 21.
SDF-MF Format of the T_SIGNALING_BUFFER (T1 and E1 Modes)
Word 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
15
0
Bit
CH1
3
5
7
9
11
13
15
17
19
21
CH0
2
4
6
8
10
12
14
16
18
20
22
NOTE: The upper nibble of each byte is 0.
T1 format uses word addresses 0 to 11.
CH30
25
24
26
27
28
29
CH31
23