CPU
CPU
CPU
CPU
CPU
CPU
CPU
CPU
x4
ASIC/
FPGA
ASIC/
FPGA
Chipset
Endpoint
Memory
Chipset
x4
PEX 8612
x4
x16
x16
x4
Memory
PEX 8612
x4
x4
Figure 5. Embedded Systems
Failover Storage Systems
The PEX 8612’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 8612 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 backup chassis. By offloading the
task of backing up data onto the secondary system,
processor and system performance is enhanced.
PCIe Gen1 or PCIe Gen2 slots
Figure 3. Fan-in/out Usage
Network Interface Cards
The PEX 8612 can also be utilized in communications
applications such as Network Interface Cards (NICs).
NICs, like the one shown in Figure 4, can utilize the
PEX 8612 for its fan-out capabilities. In the example
below, the PEX 8612 is being used on a Dual-port 10-
Gigabit Ethernet (GE) NIC card. The PEX 8612 utilizes
a x4 link to connect to the host and two x4 downstream
links to fan-out to the 10GE ports. The peer-to-peer
communication feature of the PEX 8612 allows the
endpoints to communicate with each other without any
intervention or management by the host.
Dual-Port NIC
CPU
CPU
CPU
CPU
Chipset
10 GE
MAC/PHY
Memory
x4
x4
PEX 8612
10 GE
MAC/PHY
x4
PEX 8612
x4
x4
x4
Backup Chassis
PEX 8612
x4
x4
FC
Control
PEX 8612
x4
FC
Control
x4
FC
Control
Figure 4. 10GE NIC Fan-Out
Embedded Systems
The PEX 8612 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 an embedded system
utilizing a PEX 8612 to fan-out to two ASICs/FPGAs.
FC
Control
8 Disk Chassis
8 Disk Chassis
Figure 6. Dual Cast in Storage Systems
Preliminary - PLX Confidential
PLX [ PLX TECHNOLOGY ]
