PM73121ꢀAAL1gator II
Data Sheet
PMC-Sierra, Inc.
PMC-980620
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AAL1 SAR Processor
uses the synchronization signals (TL_FSYNC and TL_MSYNC) supplied by the framer to per-
form a parallel-to-serial conversion on the outgoing data that it reads from a multiframe buffer in
the order in which it is needed.
A rising edge on TL_FSYNC indicates the beginning of a frame, and a rising edge on TL_
MSYNC indicates the beginning of a multiframe. The RFTC realigns when an edge is seen on
these signals. It is not necessary to provide an edge every frame or multiframe. Signaling data is
driven for all frames of any multiframe and will change only on multiframe boundaries. For T1
mode, signaling data may change every 24th frame. For E1 mode, signaling may change every
16th frame.
A special case of E1 mode exists that permits the use of T1 signaling with E1 framing. Normally
an E1 multiframe consists of 16 frames of 32 timeslots, where signaling changes on multiframe
boundaries. When E1_WITH_T1_SIG is set in LIN_STR_MODE and the line is in E1 mode, the
TFTC will use a multiframe consisting of 24 frames in 32 timeslots. In this mode, the
AAL1gator II reads signaling on the 24th frame of the multiframe.
The signaling nibble is valid for each channel when the last nibble of each channel’s data is being
driven. See Figure 48 for an example of signaling bits in a T1 frame. See Figure 49 for an exam-
ple of signaling bits in the E1 mode.
Line Output Signals During Every Frame
21
TL_SER
(timeslots)
0
1
2
22
ABCD
23
ABCD
XXXX
Channel 23
...
ABCD
ABCD
XXXX
ABCD
ABCD
XXXX Channel 21
TL_SIG XXXX
XXXX
...
XXXX
...
Channel 1
Channel 2
Channel 22
Channel 0
XXXX - indicates signaling is invalid
Figure 48. Output of T1 Signaling Bits
Line Output Signals During Every Frame
TL_SER
(timeslots)
0
1
2
29
30
ABCD
31
ABCD
XXXX
Channel 31
...
ABCD
ABCD
XXXX
ABCD
ABCD
XXXX Channel 29
XXXX
TL_SIG XXXX
...
XXXX
...
Channel 1
Channel 2
Channel 30
Channel 0
XXXX - indicates signaling is invalid
Figure 49. Output of E1 Signaling Bits
NOTE: The AAL1gator II treats all 32 timeslots identically. Although E1 data streams con-
tain 30 timeslots of channel data and 2 timeslots of control (timeslots 0 and 16), data
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PMC [ PMC-SIERRA, INC ]
