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Figure 3. I/O Expansion

Video Surveillance

A video surveillance application is another example for an

embedded application. When used together with a PEX8311,

PCI Express-to-local bus bridges, the PEX8505 can connect to

other embedded devices, such as FPGAs. This allows video

capture devices to interface to a PCI Express host taking

advantage of the PCI Express performance. For more

information on the PCI Express-to-Local Bus bridge, please

Figure 4. Video Surveillance

Printer Application

In a printer application, low power and low latency devices are

commonly used. Figure 5 shows an example of a printer

application. In this example, the low power processor used

provides a limited number of PCI Express ports. The PEX

8505 can be used to provide four additional PCI Express ports

for the connectivity of other system peripherals such as

Ethernet as well any proprietary PCI Express based ASICs.

The Peer-to-Peer feature in the PEX 8505, allows a peripheral

connected on a downstream port the ability to transfer data

directly to another peripheral device. As shown in Figure 5,

the ASIC connected to the scanner side can transfer data

directly to the PCIe Slot and/or the ASIC connected on the

Marking Engine side resulting in a low latency data transfer.

In this case, the processor is not directly involved in the

transfer.

Figure 5. Printer Engine

Software Usage Model

From a system model viewpoint, each PCI Express port is a

virtual PCI to PCI bridge device with its own set of PCI

Express configuration registers. It is through the upstream port

that the BIOS or host can configure the other ports using

standard PCI enumeration. The virtual PCI to PCI bridges

within the PEX 8505 are compliant to the PCI and PCI

Express system models. The Configuration Space Registers

(CSRs) in a virtual primary/secondary PCI to PCI Bridge are

accessible by type 0 configuration cycles through the virtual

primary bus interface (matching bus number, device number,

and function number).

Interrupt Sources/Events

The ExpressLane PEX 8505 switch supports the INTx

interrupt message type (compatible with the PCI 2.3 Interrupt

signals) or Message Signaled Interrupts (MSI) when enabled.

Interrupts/messages are generated by the PEX 8505 for hot

plug events, baseline error reporting, and advanced error

reporting.

PEX 8505

PCI

Bus

PCIe Sound Card

PEX 8111

VIA

17242

Stereo

CODEC

PCI

Bus

PEX 8111

CVBS

2IF

Conexant

CX23882

TS

Conexant

Demod

CX22702

Philips

Hybrid

Tuner

IF

PCIe TV Tuner Card

South

Bridge

End Point

PEX 8505

PEX 8505

PCI

Bus

PCIe Sound Card

PEX 8111

PEX 8111

VIA

17242

VIA

17242

Stereo

CODEC

Stereo

CODEC

PCI

Bus

PEX 8111

PEX 8111

CVBS

2IF

Conexant

CX23882

Conexant

CX23882

TS

Conexant

Demod

CX22702

Conexant

Demod

CX22702

Philips

Hybrid

Tuner

Philips

Hybrid

Tuner

IF

PCIe TV Tuner Card

South

Bridge

South

Bridge

End Point

Camera

Camera

Camera

JPEG

JPEG

FIFO

FIFO

FPGA

FPGA

CPU

CPU

Camera

Camera

Camera

PEX 8311

PEX 8311

PEX 8505

Control

Processor

.

.

Camera

Camera

Camera

Camera

Camera

Camera

JPEG

JPEG

FIFO

FIFO

FPGA

FPGA

CPU

CPU

CPU

CPU

Camera

Camera

Camera

Camera

Camera

Camera

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8505

PEX 8505

Control

Processor

.

.

PCIe Slot or

Cable

x1

PEX 8505

Processor

Proprietary

ASIC

Proprietary

ASIC

Ethernet

Scanner

Marking Engine

x1

x1

x1

x1

PCIe Slot or

Cable

x1

PEX 8505

Processor

Proprietary

ASIC

Proprietary

ASIC

Ethernet

Scanner

Marking Engine

x1

x1

x1

x1