RELEASED
PM73123 AAL1GATOR-8
DATASHEET
PMC-2000097
ISSUE 2
8 LINK CES/DBCES AAL1 SAR
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 of 32 timeslots.
If GEN_SYNC is set in the LIN_STR_MODE memory register for this line then
the RFTC will generate the frame pulses based on its internal counter.
The signaling nibble is valid for each channel when the last nibble of each
channel’s data is being driven unless the SHIFT_CAS bit is set in the
LIN_STR_MODE register. If the SHIFT_CAS bit is set the signaling nibble is
valid for each channel when the first channel of each channel’s data is being
driven. See Figure 52 for an example of signaling bits in a T1 frame. See Figure
53 for an example of signaling bits in the E1 mode.
Figure 52 Output of T1 Signaling Bits (SHIFT_CAS=0)
Line Output Signals During Every Frame
TL_SER
(t imeslots
...
0
1
2
21
22
ABCD
23
ABCD
XXXX
Channel 23
)
ABCD
XXXX
Channel 1
ABCD
ABCD
ABCD
XXXX Channel 21 XXXX
XXXX
...
XXXX
TL_SIG
...
Channel 2
Channel22
Channel 0
XXXX - indicates signaling is invalid
Figure 53 Output of E1 Signaling Bits (SHIFT_CAS=0)
Line Output Signals During Every Frame
TL_SER
...
0
1
2
29
30
ABCD
31
ABCD
XXXX
Channel 31
(t imeslots
)
ABCD
Channel 0
ABCD ABCD
XXXX
Channel 1 Channel 2
ABCD
XXXX Channel 29 XXXX
XXXX
XXXX
...
...
TL_SIG
Channel30
XXXX - indicates signaling is invalid
Note:
• The AAL1gator-8 treats all 32 timeslots identically. Although E1 data streams
contain 30 timeslots of channel data and 2 timeslots of control (timeslots 0
and 16), data and signaling for all 32 timeslots are stored in memory and can
be sent and received in cells.
PMC-SIERRA, INC. PROPRIETARY AND CONFIDENTIAL
134
PMC [ PMC-SIERRA, INC ]
