Ambassador T8100A, T8102, and T8105
H.100/H.110 Interfaces and Time-Slot Interchangers
Advance Data Sheet
November 1999
The streams are scanned in intervals equal to
2 Architecture and Functional
Description (continued)
8.192 Mbits/s time slots: first group A from 0 through 7,
then group B from 8 through 11, then group C from 12
through 15. If a group is active, the data is input from or
output to the streams in that group. If a group is operat-
ing below 8.192 Mbits/s and has already been scanned
(at the 8.192 Mbits/s rate), then the data transfer oper-
2.2 Local Bus Section (continued)
2.2.3 Data Rates and Time-Slot Allocation
At its maximum, the T8100A and the T8105 will be able
to process 1024 nonblocking local-to-local connections.
The data rate 8.192 Mbits/s corresponds to 128 time
slots, 4.096 Mbits/s corresponds to 64 time slots, and
2.048 Mbits/s corresponds to 32 time slots. Since differ-
ent data rates require different amounts of memory, the
local memory can be filled in a number of ways. A non-
blocking switch permits any time slot on any stream to
be switched to another time slot on any stream in any
direction.
ation is ignored.
For addressing, the user directly provides stream and
time-slot information. The devices will map this into the
physical memory, regardless of which stream groups
are active or at what rate. While this makes program-
ming simpler, it makes the internal operation more diffi-
cult to understand. Several diagrams are required to
illustrate how the memory utilization works.
Unassigned time slots in the local output section are
3-stated. Therefore, multiple lines can be connected
together.
The local streams are arranged in three groups: A,
B, and C. Group A corresponds to the local data pins
0—7, group B with local data pins 8—11, and group C
with local data pins 12—15. The groups may be oper-
ated at any of the three data rates: 2.048 Mbits/s,
4.096 Mbits/s, or 8.192 Mbits/s; however, group B is
activated only when group A is operating below
8.192 Mbits/s. Likewise, group C is activated when
group B is operating below 8.192 Mbits/s.
Figure 6 below shows the overall structure of the local
memory:
Note: Both the connection and two data memories are
arranged in four blocks of 256 locations each
(i.e., 4 x [4 x 64]).
The arrangement is important to establishing a mem-
ory fill pattern which supports all of the various groups
and rates. The rows of each memory, which are split
into four groups of 4, correspond to the 16 streams.
The columns correspond to 64 time-slot addresses.
Note: In order to efficiently fill the memory, the mem-
ory locations are read or filled in the same order
regardless of their activation or rate.
4
4
4
4
4
4
4
4
CONNECTION
MEMORY
DATA MEMORY 0
DATA MEMORY 1
LOCATION 0
LOCATION 15
EACH (SMALL) SQUARE
REPRESENTS 15 bits
OF CONNECTION
INFORMATION
EACH (SMALL)
SQUARE
REPRESENTS
1 byte OF DATA
TO/FROM
LOCAL
STREAMS
64
64
LOCATION 1023
5-6104F
Figure 6. Local Streams, Memory Structure
Lucent Technologies Inc.
25
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