PEX 8680, PCI Express Gen 2 Switch, 80 Lanes, 20 Ports

© PLX Technology, www.plxtech.com

Page 1 of 1

5/14/2009, Version 1.1

Features

PEX 8680 General Features

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80-lane, 20-port PCIe Gen2 switch

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Integrated 5.0 GT/s SerDes

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35 x 35mm

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Typical Power: 9.0 Watts

PEX 8680 Key Features

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Standards Compliant

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PCI Express Base Specification, r2.0

(backwards compatible w/ PCIe r1.0a/1.1)

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PCI Power Management Spec, r1.2

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Microsoft Vista Compliant

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Supports Access Control Services

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Dynamic link-width control

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Dynamic SerDes speed control

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High Performance

♦ performancePAK

Read Pacing (bandwidth throttling)

Multicast

Dynamic Buffer/FC Credit Pool

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Non-blocking switch fabric

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Full line rate on all ports

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Packet Cut-Thru with 176ns max packet

latency (x16 to x16)

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2KB Max Payload Size

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Flexible Configuration

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Ports configurable as x1, x2, x4, x8, x16

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Registers configurable with strapping

pins, EEPROM, I

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Lane and polarity reversal

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Compatible with PCIe 1.0a PM

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Multi-Host & Fail-Over Support

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Configurable Non-Transparent (NT) port

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Failover with NT port

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Up to Six upstream/Host ports with 1+1

or N+1 failover to other upstream ports

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Quality of Service (QoS)

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Eight traffic classes per port

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Weighted round-robin source

port arbitration

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Reliability, Availability, Serviceability

♦ visionPAK

Per Port Performance Monitoring

Per port payload & header counters

SerDes Eye Capture

Error Injection and Loopback

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4 Hot Plug Ports with native HP Signals

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All ports hot plug capable thru I

(Hot Plug Controller on every port)

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ECRC and Poison bit support

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Data Path parity

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Memory (RAM) Error Correction

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INTA# and FATAL_ERR# signals

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Advanced Error Reporting

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Port Status bits and GPIO available

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Per port error diagnostics

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JTAG AC/DC boundary scan

The ExpressLane

switching capability enabling users to connect multiple hosts to their

respective endpoints via scalable, high bandwidth, non-blocking

interconnection to a wide variety of applications including servers,

storage systems, and communications platforms. The PEX 8680 is

well suited for fan-out, aggregation, and peer-to-peer applications.

Multi-Host Architecture

The PEX 8680 employs an enhanced version of PLX’s field tested PEX 8648

PCIe switch architecture, which allows users to configure the device in

legacy single-host mode or multi-host mode with up to six host ports capable

of 1+1 (one active & one backup) or N+1 (N active & one backup) host

failover. This powerful architectural enhancement enables users to build

PCIe based systems to support high-availability, failover, redundant and

clustered systems.

High Performance & Low Packet Latency

The PEX 8680 architecture supports packet cut-thru with a maximum

latency of 176ns (x16 to x16). This, combined with large packet memory,

flexible common buffer/FC credit pool and non-blocking internal switch

architecture, provides full line rate on all ports for performance-hungry

applications such as servers and switch fabrics. The low latency enables

applications to achieve high throughput and performance. In addition to low

latency, the device supports a packet payload size of up to 2048 bytes,

enabling the user to achieve even higher throughput.

Data Integrity

The PEX 8680 provides end-to-end CRC (ECRC) protection and Poison bit

support to enable designs that require end-to-end data integrity. PLX also

supports data path parity and memory (RAM) error correction circuitry

throughout the internal data paths as packets pass through the switch.

Flexible Configuration

The PEX 8680’s 20 ports can be configured to lane widths of x1, x2, x4, x8,

or x16. Flexible buffer

allocation, along with the

device's flexible packet

flow control, maximizes

throughput for applications

where more traffic flows in

the downstream, rather than

upstream, direction. Any

port can be designated as the

upstream port, which can be

changed dynamically.

Figure 1 shows some of the

PEX 8680’s common port

configurations in legacy

Single-Host mode.

Figure 1. Common Port Configurations

PEX 8680

PEX 8680

PEX 8680

PEX 8680

x4

PEX 8680

PEX 8680

PEX 8680

PEX 8680

x8

PEX 8680

PEX 8680

PEX 8680

PEX 8680

x8

PEX 8680

PEX 8680

PEX 8680

PEX 8680

x16

19 x4

6 x4

6 x8

10 x4

8 x8

4 x8