System Controller Card

The PEX 8311 bridge, with its Root Complex mode

support, simplified generic local bus interface, PCIe

protocol packet conversion, and multiple DMA

controllers allows users to use the device as a “north

bridge” type application in embedded systems. Such

controllers often manage “control path” data. The local

bus has the capability to support numerous simultaneous

local bus devices. Figure 2 shows the bridge interfacing

a local processor, FPGA, and memory to a downstream

PCIe port. The PCIe port connects to a switching fabric

or I/O card.

Figure 2. “Northbridge” Host Bridge

Line Card Application

The number and variety of PCI Express native-mode

devices is growing quickly. As these devices become

mainstream, it will be necessary to create multifunction

and multi-port adapter cards with PCI Express

capability.

The PEX 8311 can be used to create a communications

line card that bridges a local processing device and

memory to an upstream PCIe port. The bridge allows a

line card to be a backplane or a motherboard. Figure 3

shows the PEX 8311 in this application. In this mode,

the bridge acts in an “EndPoint mode”. Configuration to

the bridge comes from the PCIe. Use of DMA for data

path and higher priority simultaneous Direct

Master/Slave for control path data is invaluable.

Figure 3. Communications Line Card

Industrial Control Systems

The PEX 8311 is an excellent choice to bridge

programmable logic, local processors, and other devices

PCI Express

FPGA

DSP

Proprietary

ASIC

Generic Local Bus

EEPROM

Local Based

CPU

SRAM/

PEX 8311

PCI Express

FPGA

DSP

Proprietary

ASIC

Generic Local Bus

EEPROM

Local Based

CPU

SRAM/

PEX 8311

x1 PCIe

Local Bus: 66 MHz, 32-bit

EEPROM

COM 1

Flash

SRAM

NPU

ASIC

COM 2

COM N

PEX 8311

x1 PCIe

Local Bus: 66 MHz, 32-bit

EEPROM

COM 1

Flash

SRAM

NPU

ASIC

COM 2

COM N

PEX 8311

to a PCIe switch. The bridge is fully interoperable with

PCIe switches from a variety of PCIe products including

multiple switches from PLX Technology with lane

counts from 8 to 32. Figure 4 illustrates PEX 8311

bridging programmable logic devices to the PEX 8524

switch. One of the many applications for the bridge is to

interface inputs via an FPGA from industrial signals

from the manufacturing floor to a PCIe switch where the

data is sent to a local processor and then to a central host

for system control applications. This use can be

generalized to many similar bridging operations such as

in instrumentation or medical imaging.

Figure 4. Industrial Control

In this type application, the bridge’s x1 lane PCIe 2.5 Gbps

bandwidth in combination with its large local bus capacitive

loading can support up to five simultaneous input sources on

each PEX 8311. With a Local Bus of up to 66 MHz and

32-bit data, complete bandwidth matching with the PCIe

port can be achieved in unidirectional designs.

Video Surveillance System

The PEX 8311 is a very economical bridge and can

support many “mass market” applications. These

applications include PC television capture cards, data

acquisition boards, video editing, and surveillance

systems. The later is shown in Figure 5 below. This

design allows multiple camera sources to feed their

inputs through a series of compression, buffering stages

and local processing and be bridged to a PCIe switch or

directly to a PCIe slot on a motherboard. The PC then

allows security personnel to monitor multiple feeds and

switch interactively among the various feeds. Video

editing by consumers could use a similar design

topology as well.

Figure 5. Video Surveillance System

CPU

SDRAM

FPGA

FPGA

FPGA

FPGA

250MB/s

250MB/s

250MB/s

250MB/s

PEX

8524

To Host

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8524

CPU

SDRAM

FPGA

FPGA

FPGA

FPGA

PEX

8524

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8524

CPU

SDRAM

FPGA

FPGA

FPGA

FPGA

PEX

8524

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8524

CPU

SDRAM

FPGA

FPGA

FPGA

FPGA

PEX

8524

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8524

JPEG

FIFO

FPGA

Camera

Camera

Camera

JPEG

FIFO

FPGA

Camera

Camera

Camera

M

o

t

h

e

r

b

o

a

r

d

CPU

CPU

PEX 8311

PEX 8311

PEX 8524

JPEG

FIFO

FPGA

JPEG

FIFO

FPGA

CPU

CPU

CPU

CPU

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8524

JPEG

FIFO

FPGA

Camera

Camera

Camera

JPEG

FIFO

FPGA

Camera

Camera

Camera

CPU

CPU

CPU

CPU

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8524

JPEG

FIFO

FPGA

JPEG

FIFO

FPGA

CPU

CPU

CPU

CPU

PEX 8311

PEX 8311

PEX 8311

PEX 8311

PEX 8524