PEX 8625, PCI Express Gen 2 Switch, 24 Lanes, 24 Ports
Highlights
The ExpressLane™ PEX 8625 device offers Multi-Host PCI Express
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
communications platforms. The PEX 8625 is well suited for fan-out,
aggregation, and peer-to-peer applications.
PEX 8625 General Features
o 24-Lane, 24-port PCIe Gen2 switch
- Integrated 5.0 GT/s SerDes
o 35 x 35mm2, 1156-ball FCBGA package
o Typical Power: 8.5 Watts
PEX 8625 Key Features
o Standards Compliant
Multi-Host Architecture
- PCI Express Base Specification, r2.0
(backwards compatible w/ PCIe
r1.0a/1.1)
- PCI Power Management Spec, r1.2
- Microsoft Vista Compliant
- Supports Access Control Services
- Dynamic link-width control
- Dynamic SerDes speed control
o High Performance
The PEX 8625 employs an enhanced version of PLX’s field tested PCIe
switch architecture, which allows users to configure the device in legacy
single-host mode or multi-host mode with up to Eight 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.
♦ performancePAK
9 Read Pacing (bandwidth throttling)
9 Multicast
9 Dynamic Buffer/FC Credit Pool
- Non-blocking switch fabric
- Full line rate on all ports
- Packet Cut-Thru with 200ns max packet
latency (x1 to x1)
- 2KB Max Payload Size
High Performance & Low Packet Latency
The PEX 8625 architecture supports packet cut-thru with a maximum
latency of 200ns (x1 to x1). 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.
o Flexible Configuration
- Ports configurable as x1, x4
- Registers configurable with strapping
pins, EEPROM, I2C, or host software
- Lane and polarity reversal
- Compatible with PCIe 1.0a PM
o Multi-Host & Fail-Over Support
- Configurable Non-Transparent (NT) port
- Failover with NT port
- Up to Eight upstream/Host ports with
1+1 or N+1 failover to other upstream
ports
o Quality of Service (QoS)
- Eight traffic classes per port
- Weighted round-robin source
port arbitration
Data Integrity
The PEX 8625 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 8625’s 24 Ports can be
configured to lane widths of x1
or x4. Flexible buffer allocation,
along with the device's flexible
packet flow control, maximizes
throughput for applications
where more traffic flows in the
o Reliability, Availability, Serviceability
♦ visionPAK
9 Per Port Performance Monitoring
Per port payload & header counters
9 SerDes Eye Capture
9 Error Injection and Loopback
- 3 Hot Plug Ports with native HP Signals
- All ports hot plug capable thru I2C
(Hot Plug Controller on every port)
- ECRC and Poison bit support
- Data Path parity
- Memory (RAM) Error Correction
- INTA# and FATAL_ERR# signals
- Advanced Error Reporting
- Port Status bits and GPIO available
• Per port error diagnostics
- JTAG AC/DC boundary scan
downstream,
rather
than
upstream, direction. Any port
can be designated as the
upstream port, which can be
changed dynamically. Figure 1
shows the available PEX 8625’s
port configurations in legacy
Single-Host mode.
© PLX Technology, www.plxtech.com
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10/8/2009, Version 1.0