Ambassador T8100A, T8102, and T8105
H.100/H.110 Interfaces and Time-Slot Interchangers
Advance Data Sheet
November 1999
2 Architecture and Functional Description (continued)
2.3 H-Bus Section (continued)
2.3.4 L-Bus Access
The input and output of the CAM have the appropriate links to the local stream pins so that the H-bus streams may
be routed to and from the local bus streams. The LBS register (Section 2.2.4 LBS: Local Stream Control, 0x0C)
programs the local stream rates even if accessed by the CAMs. To address the local bus CAM block, the two most
significant address bits of the physical address are set to the appropriate values as described in Figure 9. The
other bits form the comparand along with a read/write bit. When the CAM is outputting data to the local bus, it has
priority over the local bus memory. In other words, if both the local bus and H-bus access the same local stream
and time slot, the H-bus data memory will provide the actual data, not the local connection.
2.3.5 H-Bus Rate Selection and Connection Address Format
Operating rates are selected in a manner similar to the local side. Two registers, HSH and HSL, shown below,
define the operation of the 32 streams. Again, SGx refers to stream groups: HSH holds SGh—SGe where SGh
programs streams 28—31, SGg programs streams 24—27, SGf programs streams 20—23, and SGe programs
streams 16—19. HSL holds SGd—SGa where SGd programs streams 12—15, SGc programs streams 8—11,
SGb programs streams 4—7, and SGa programs streams 0—3.
Table 43. HSL: H-Bus Stream Control, Low Byte, 0x10
Reg
R/W
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
HSL
—
SGd
SGc
SGb
SGa
Symbol
Bit
7
Description
H-Bus Group D Rate Select, MSB. Programs streams 12—15. SGn = 00, 3-state
SGd
SGn = 01, 2.048 Mbits/s
SGn = 10, 4.096 Mbits/s
SGn = 11, 8.192 Mbits/s
6
H-Bus Group D Rate Select, LSB.
SGc
SGb
SGa
5
H-Bus Group C Rate Select, MSB. Programs streams 8—11.
H-Bus Group C Rate Select, LSB.
4
3
2
1
0
H-Bus Group B Rate Select, MSB. Programs streams 4—7.
H-Bus Group B Rate Select, LSB.
H-Bus Group A Rate Select, MSB. Programs streams 0—3.
H-Bus Group A Rate Select, LSB.
Lucent Technologies Inc.
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