Preliminary - PLX Confidential

x4

CPU

CPU

CPU

CPU

CPU

CPU

CPU

CPU

PEX 8612

PEX 8612

PEX 8612

PEX 8612

x4

Memory

Memory

Memory

Memory

x16

x16

x4

Chipset

Chipset

Chipset

Chipset

PCIe Gen1 or PCIe Gen2 slots

Endpoint

Endpoint

Endpoint

Endpoint

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.

10 GE

10 GE

MAC/PHY

MAC/PHY

MAC/PHY

MAC/PHY

MAC/PHY

MAC/PHY

MAC/PHY

MAC/PHY

x4

x4

x4

Dual-Port NIC

Dual-Port NIC

PEX 8612

PEX 8612

PEX 8612

PEX 8612

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.

x4

CPU

CPU

CPU

CPU

CPU

CPU

CPU

CPU

Memory

Memory

Memory

Memory

PEX 8612

PEX 8612

PEX 8612

PEX 8612

ASIC/

FPGA

ASIC/

FPGA

ASIC/

FPGA

ASIC/

FPGA

ASIC/

FPGA

ASIC/

FPGA

ASIC/

FPGA

ASIC/

FPGA

x4

x4

Chipset

Chipset

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.

8 Disk Chassis

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

8 Disk Chassis

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

x4

x4

x4

x4

PEX 8612

PEX 8612

PEX 8612

PEX 8612

PEX 8612

PEX 8612

PEX 8612

PEX 8612

x4

CPU

CPU

CPU

CPU

CPU

CPU

CPU

CPU

Memory

Memory

Memory

Memory

Chipset

Chipset

Chipset

Chipset

PEX 8612

PEX 8612

PEX 8612

PEX 8612

x4

x4

Figure 6. Dual Cast in Storage Systems