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Port Configurations

The lane width of each port can be individually configured

through auto-negotiation, hardware strapping, host software

The PEX 8505 supports three port configurations:

1) One x1 upstream port and four x1 downstream ports

2) One x2 upstream port and three x1 downstream ports

3) One x2 upstream port, one x2 downstream port, one x1

downstream port

Figure 1. Port Configurations

Hot-Plug for High Availability

Hot-Plug capability allows users to replace hardware modules

and perform maintenance without powering down the system.

The PEX 8505 Hot-Plug capability and Advanced Error

Reporting features make it suitable for High Availability

(HA) applications. Ports 1, 2 & 3 include a Standard Hot-

Plug Controller. If the PEX 8505 is used in an application

where one or more of its downstream ports connect to PCI

Express slots, Hot-Plug Controllers on the three downstream

ports can be used to manage the hot plug event of its

associated slot.

Fully Compliant Power Management

For applications that require power management, the

ExpressLane PEX 8505 devices support both link (L0, L0s,

L1, L2/L3 Ready and L3) and device (D0 and D3hot) power

management states, in compliance with the PCI Express power

management specification.

SerDes Power and Signal Management

The ExpressLane PEX 8505 supports software control of the

SerDes outputs to allow optimization of power and signal

strength in a system. The PLX SerDes implementation

supports four levels of power – off, low, typical, and high. The

SerDes block also supports loop-back modes and advanced

reporting of error conditions, which enables efficient debug

and management of the entire system.

Port Arbitration

The PEX 8505 switch supports hardware fixed and Weighted

Round-Robin Ingress Port Arbitration. This allows fine

tuning of Quality of Service and efficient use of packet buffers

and the system bandwidth.

Applications

Suitable for control plane applications, multi-function

printers, DVRs, industrial control systems, medical

imaging systems, embedded systems & AMC modules, the

PEX 8505 can be configured for a wide variety of form factors

and applications.

Control Plane Application

The PEX 8505 is ideal for migrating existing PCI control

planes in routers to high-speed PCI Express interface to meet

increased packet processing needs. Figure 2 shows a controller

card with a PEX 8505 connecting the Control Processor to as

many as four devices each via a x1 port. This usage model

provides connectivity to multiple devices giving the processor

control over multiple devices in mid-range routers.

Figure 2. Control Plane

I/O Expansion

The PEX8505 can be used in I/O expansion applications.

Together with a PCI Express-to-PCI bridge, the PEX8505 is

capable of providing legacy PCI I/O expansion support. Each

x1 port in the PEX8505 provides 250MB/s bandwidth per

direction and it is more than capable of supporting the various

bus widths and bus speeds of legacy PCI. Please visit the

PLX’s PCI Express bridge family.

PEX 8505

x1

PEX 8505

x2

x1

x2

x1 x1 x1

PEX 8505

x1

x1 x1 x1 x1

PEX 8505

PEX 8505

x1

PEX 8505

PEX 8505

x2

x1

x2

x1 x1 x1

PEX 8505

x1

x1 x1 x1 x1

PEX 8505

PEX 8505

x1

x1 x1 x1 x1

PEX 8505

Control

Processor

FPGA

ASIC

FPGA

ASIC

Memory

PEX 8505

Control

Processor

FPGA

ASIC

FPGA

ASIC

Memory