CPU
CPU
CPU
CPU
I/O Blades
Switch
Fabric
Chipset
Endpoint
Memory
x16
x16
x8
PEX 8624
Endpoint
x4
x4
x4
x4
NT
PEX 8624
Backplane
PCIe Gen1 or PCIe Gen2 slots
Figure 3. Fan-in/out Usage
Advanced Mezzanine Cards
The PEX 8624’s fan-out capabilities can be utilized on
Advanced Mezzanine Cards (AMC) for I/O expansion.
In the example shown below in Figure 4, the PEX 8624
is used on a Quad-Port Network Interface Card (NIC) in
an AMC form factor. The PEX 8624 uses a x8 upstream
link to the host and four x4 downstream links to to fan-
out to the four MAC/PHY controllers.
10GE
10GE
10GE
10GE
MAC/PHY
MAC/PHY
MAC/PHY
MAC/PHY
Figure 5. Bladed Embedded System
Failover Storage Systems with Dual Cast
The PEX 8624’s Dual Cast feature proves to be very
useful in storage systems. In the example shown in
Figure 6, the Dual Cast feature enables the PEX 8624 to
copy data coming from the host to two downstream ports
(see yellow traffic patterns) in one transaction as
opposed to having to execute two separate transactions
to send data to the redundant chassis. By offloading the
task of backing up data onto the secondary system,
processor and system performance is enhanced. The
PEX 8624’s NT port is used to isolate the backup system
from the primary system.
CPU
CPU
CPU
CPU
CPU
CPU
CPU
CPU
x4
x4
x8
x4
x4
Backup
System
PEX 8624
Chipset
x8
Memory
Chipset
x8
Memory
Figure 4. Quad-Port 10GE NIC AMC
PEX 8624
x8
NT
PEX 8624
x4
x4
x4
Embedded Systems
The PEX 8624 is well suited for embedded applications
as well. Embedded applications, like the example shown
in Figure 5, commonly use a number of independent
modules for functions such as control plane processing,
data acquisition, or image processing to name a few
possibilities. Figure 5 represents a bladed embedded
system utilizing a PEX 8624 to fan-out to the I/O
Modules. The PEX 8624’s NT port isolates the
processors on the two switch fabrics.
x4
NT
NT
PEX 8616
x4
FC
Control
PEX 8616
x4
FC
Control
x4
FC
Control
x4
FC
Control
8 Disk Chassis
8 Disk Chassis
Figure 6. Dual Cast in Storage Systems
Preliminary - PLX Confidential
PLX [ PLX TECHNOLOGY ]
