shows a controller card with a PEX 8618 connecting the
Control Processor to as many as fifteen line cards each via an
x1 connection. This usage model provides connectivity to
multiple line cards giving the processor control over a large
number of line cards in communication platforms.
Figure 5. Packet Processing Module
Intelligent Adapter Card
The PEX 8618 supports the
non-transparency
feature.
Figure 6 illustrates a host system using an intelligent adapter
card.
Figure 6. Intelligent Adapter Usage
Figure 3. Control Plane Application
Control Planes for Large Systems
Two PEX 8618 devices can be used in applications where
there is need for more than 15 line cards and the processor has
2 PCIe ports. An example of a control plane application with
more than 15 line cards is shown in Figure 4.
In this figure, the CPU on the adapter card is isolated from the
host CPU. The PEX 8618 non-transparent port allows the two
CPUs to be isolated but communicate with each other through
various registers that are designed in the PEX 8618 for that
purpose. The host CPU
can dynamically re-assign both the
upstream port and the non-transparent port
of PEX 8618
allowing the system to be reconfigured.
Active-Standby Failover Model
The PEX 8618 supports applications requiring
dual host, host
failover
applications through the
non-transparency
feature.
Figure 7 illustrates a dual host system with an active and
standby processor configuration.
The redundancy of the host and the fabric can be achieved
through many possible configurations using NTB function of
PEX 8618. In the configuration shown below Processor A is
the primary active host of the PCI Express system. Processor
B acts as the backup Host. In the case of a failure on Processor
A, application software is instructed to migrate the PCI
Express system to Processor B. Consequently, Processor B
becomes the active host and Processor A can be replaced as
the backup Host.
Figure 4. Control Planes for Large Systems
Embedded Control Planes
The PEX 8618 is well suited for embedded control plane
applications. An example of such application is a packet
processing module, as shown in Figure 5. In this example, the
FPGAs and ASICs implement an x1 PCI Express Interface.
With its high port count, the PEX 8618 can provide
connectivity to a high number of FPGAs and ASICs for a
robust packet processing communications sub-system.
Figure 7. Active-Standby Host Mode
PLX [ PLX TECHNOLOGY ]
