PM8621-BI PMC-Sierra, Inc., PM8621-BI Datasheet - Page 25

• Manufacturer Part Number: PM8621-BI
• Description: Driver, NSE/SBS Narrowband Chipset Driver
• Manufacturer: PMC-Sierra, Inc.

Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2021248, Issue 1
Table 2: Narrowband Chipset Scalable Fabric with NSE-8G
On the line/service card side, the CSD supports the addition/deletion of new chipset components
into the system without affecting the operation of the existing fabric. For instance, a new line card
with SBS devices can be added to the CSD when there is additional link requirements. Such an
action does not affect the operation of the existing links. Similarly, a faulty line card can be taken
out of service without affecting the rest of the system. The assumption is that the chipset system
is built on a backplane technology with hot-swap capability.
TeleCombus and SBI Bus Mode Switching
In TeleCombus mode, the switching granularity is VT1.5/VT2. The CSD takes advantage of the
column-switching mode available in the hardware to support the switching operation. The
advantage is simpler and faster connection setup since connection setting is specified for the
entire column, not just on a per-DS0 basis. Each SBS in the chipset can be set up for quad 19.44
MHz TeleCombus or single 77.76 MHz TeleCombus operation.
In SBI mode, the finest switching granularity is DS0. Each SBS device can be configured to work
in a quad SBI (19.44 MHz) or single SBI336 (77.76 MHz) mode. In addition, CAS processing
can be enabled/disabled on a per-tributary basis for DS0s with CAS bytes associated with them.
Alternately, the CSD can set up the chipset to operate in a column-switching mode, similar to the
TeleCombus mode if no DS0 routing is expected.
3
3
3
Stage
1
3
3
3
3
3
8
16
32
Depth
1
2
3
4
6
12
24
48
96
NSE-8G
1
6
9
12
18
36
256
512
1024
SBS
12
24
36
48
72
144
Narrowband Chipset Device Driver Manual
160
320
640
Bandwidth (Gbps)
8
16
24
32
48
96
Narrowband Chipset Overview
25