Almost all (non x86 based) high-end microprocessor

manufacturers are offering PCI Express interfaces. The PEX

8524 can be directly connected to a processor to fan-out its

PCIe port to a larger number of ports for enhanced

connectivity as illustrated in Figure 3.

Figure 3. Fan out for PowerPC/MIPS CPUs

Embedded Systems

The PEX 8524 can also be utilized in embedded applications.

Figure 4 shows several independent modules connecting

through the PEX 8524. The port widths for each module can

be configured as required. The peer-to-peer communication

feature of the PEX 8524 allows these modules to communicate

with each other without any centralized control.

Figure 4. Embedded Systems

Peer to Peer Communication

Figure 5 represents a backplane where the ExpressLane PEX

8524 provides peer-to-peer data exchange for a large number

of line cards where the CPU/Host plays the management role.

Figure 5. Peer-to-Peer Usage

Graphics Fan-out Switch

As PCIe based graphics cards become more mainstream, it

will be necessary to take a x8 port on the root complex device

and fan it out to two x8 ports for dual graphics applications.

Root Complex (Northbridge) devices are available with

multiple PCIe ports. These ports can be further expanded to

connect to a larger number of I/Os or to support dual-graphics

using the PEX 8524 as shown in Figure 6.

Figure 6. Graphics Fan-out

PCI Express Port Expansion

The PEX 8524 enables designers to take, for example, two x8

PCIe ports and expand them into ten ports. Some of these

PCIe ports can be bridged to PCI or PCI-X using bridging

products from PLX. Figure 7 illustrates one of the many

configurations the PEX 8524 can support.

Figure 7. PCIe Port Expansion