(PCIe to PCI bridge). The four ports in the PEX8604 provide
connectivity between the processor to up to three peripherals
each via an x1 connection. This usage model provides
connectivity within a set top box between the control
processor and the various endpoints.
Intelligent Adapter Card
The PEX 8604 supports the
non-transparency
feature.
Figure 6 illustrates a host system using an intelligent adapter
card.
Figure 3. Set Top Box
Mobile Wireless Adaptor
PEX 8604 devices can be used in applications where low
power consumption is of importance as is the case in mobile
applications. An example of a mobile wireless adapter card is
shown in Figure 4.
Figure 6. Intelligent Adapter Usage
In this figure, the CPU on the adapter card is isolated from the
host CPU. The PEX 8604 non-transparent port allows the two
CPUs to be isolated but communicate with each other through
various registers that are designed in the PEX 8604 for that
purpose. The host CPU
can dynamically re-assign both the
upstream port and the non-transparent port
of PEX 8604
allowing the system to be reconfigured.
Active-Standby Failover Model
The PEX 8604 supports applications requiring
dual host, host
failover
applications through the
non-transparency (NTB)
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 8604. 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. Mobile Wireless Adaptor
Embedded Mezzanine Module
The PEX 8604 is well suited for mezzanine module
applications. Figure 5 shows that the mezzanine card has a
local processor and a local PCIe hierarchy with the PEX8604
and multiple endpoints. Additionally, the
non-transparent
port in the PEX8604 allows the mezzanine to interface with
the main CPU in the Baseboard as well as other mezzanine
modules.
Figure 5. PCI Express Mezzanine Module
Figure 7. Active-Standby Control Plane
PLX [ PLX TECHNOLOGY ]
