PM8621-BI PMC-Sierra, Inc., PM8621-BI Datasheet - Page 23

• 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
The chipset driver is designed to be flexible and can easily be adapted to various system
configurations. Some of the typical system configurations are shown in the following. A typical
centralized configuration (Figure 1) has all SBS(s) and NSE(s) under the control of one
microprocessor that also runs the OPA library; a distributed configuration (Figure 2) has SBS(s)
controlled by one microprocessor and then the NSE(s) by a different microprocessor, which may
also host the OPA library optionally. Additional microprocessor can be deployed to host the OPA
library for dedicated processing.
Figure 2: NSE/SBS Switching Fabric - Distributed System Model
In-band communication links via LVDS between SBSs and NSEs are provided to facilitate inter-
device (or inter-card) communication. In a distributed configuration, one of the intended
applications is to distribute switch fabric settings from the NSE side to the remote SBSs. The
chipset driver provides functionality to receive and transmit messages using these links. However,
the definition of the in-band link message content/format and the design of any additional
communication protocol running on top of the link are beyond the scope of the chipset driver and
are left to the user application.
Centralized and Distributed System Configurations
In a centralized configuration, the chipset driver API interacts with all NSE and SBS devices that
are controlled by one microprocessor. In a distributed configuration, multiple instances of the
chipset driver can be deployed to run under multiple microprocessors. The configuration of each
of the instances varies depending on whether it is a line or switch card. The interface for all
configurations remains the same for the applicable features.
In a distributed configuration, each CSD instance is configured according to the devices under its
control. For instance, a typical line card may consist of some PHY layer devices and one or more
SBS devices. This CSD will then be configured to run just the SBS device driver and all the
physical SBS devices on the line card. In a typical switch card that consists of NSE devices, the
CSD instance will be configured to run with the NSE device driver and/or the OPA. All NSE
devices will be registered (added) as physical devices attached to the card and the remote SBS
devices will be registered as logical devices.
uP
uP
TEMUX84
TEMUX84
SBS-Lite
SBS-Lite
Line Card
Line Card
LVDS
Cable
LVDS
Cable
NSE-20G
NSE-20G
uP
Switch Card
Narrowband Chipset Device Driver Manual
LVDS
Cable
LVDS
Cable
SBS-Lite
uP
uP
SBS
Narrowband Chipset Overview
FREEDM336
AAL1gator32
Service Card
Service Card
23