PM8621-BI PMC-Sierra, Inc., PM8621-BI Datasheet - Page 59

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

3.5
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2021248, Issue 1
Replacing Working Line/Service Card
In the event when a line/service card needs be replaced, it can be taken out without affecting the
rest of the cards and traffic flow.
1. First removes all connections to the SBS to be removed
2. Call
3. Add a SBS device in the new line card using the sequence described in previous section.
4. Assuming the old SBS is 1+1 protected by another SBS that has been active since the
5. Establish the 1+1 protection between the new SBS and the protection SBS by calling
Event Processing
The Narrowband Chipset driver supplies all the callback functions for the underlying device
drivers. When an underlying event occurs and is detected by the hardware, an interrupt is
generated and serviced by the corresponding device driver which invokes a callback to the upper
layer application, in this case, the narrowband chipset driver. The CSD then processes the
callbacks and forwards them to the application code for events that are enabled.
The following is an overview of the interrupt service model used in the device drivers to service
device interrupts. Please refer to the NSE and SBS device driver user manual documents for more
details in interrupt processing. Basically, the device driver services the device interrupts using an
Interrupt-Service Routine (ISR) that traps interrupts. In the ISR, the device driver reads the
master interrupt status registers to find out what the interrupt cause(s) is and sends the necessary
information to the deferred processing routines (DPR) that actually process the interrupt
conditions and clears them. This architecture enables the ISR to execute quickly and then exit.
Most of the time-consuming processing of the interrupt conditions is deferred to the DPR by
queuing the necessary interrupt-context information to the DPR task. The DPR function runs in
the context of a separate task within the RTOS. The DPR then processes the interrupt
information and takes appropriate action based on the specific interrupt condition detected. As the
nature of this processing can differ from system to system, DPR calls different indication
callbacks for different interrupt conditions.
The CSD receives these callbacks from the underlying device drivers, processes them, sorts them
according to their categories and then issues callbacks to the upper application layers. Application
has the option to enable and disable any events. After initialization, the CSD by default enables
all events and reports them to the application code unless they are turned off by the application.
Some events are recommended to be on at all times under normal circumstances such as in-band
link events. They are by default, turned on by the CSD.
working SBS is taken out of service, call
between the protected SBS and the new SBS.
nbcsFmgtSetProtect
to restore traffic flow in the new working SBS.
nbcsReset
and then
and perform a switchover by calling
nbcsDelete
to remove the SBS from the fabric.
nbcsStswCopyPage
Narrowband Chipset Device Driver Manual
nbcsFmgtSwitchProtect
to synchronize the setting
Software Architecture
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