PEX 8649, PCI Express Gen 2 Switch, 48 Lanes, 12 Ports
Highlights
PEX 8649 General Features
o
48-lane, 12-port PCIe Gen2 switch
-
Integrated 5.0 GT/s SerDes
o
27 x 27mm
2
, 676-ball FCBGA package
o
Typical Power: 6.7 Watts
The ExpressLane™ PEX 8649 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
servers,
storage systems, and communications platforms.
The PEX 8649 is well
suited for
fan-out, aggregation, and peer-to-peer
applications.
Multi-Host Architecture
The PEX 8649 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 four 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 8649 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 8649 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 8649’s 12 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 8649’s
common port configurations in legacy
Single-Host mode.
PEX 8649 Key Features
o
Standards Compliant
-
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
♦
performancePAK
Read Pacing (bandwidth throttling)
Multicast
Dynamic Buffer/FC Credit Pool
-
Non-blocking switch fabric
-
Full line rate on all ports
-
Packet Cut-Thru with 176ns max packet
latency (x16 to x16)
-
2KB Max Payload Size
o
Flexible Configuration
-
Ports configurable as x1, x2, x4, x8, x16
-
Registers configurable with strapping
pins, EEPROM, I
2
C, 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 Four 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
o
Reliability, Availability, Serviceability
♦
visionPAK
Per Port Performance Monitoring
Per port payload & header counters
SerDes Eye Capture
Error Injection and Loopback
-
3 Hot Plug Ports with native HP Signals
-
All ports hot plug capable thru I
2
C
(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
© PLX Technology, www.plxtech.com
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5/14/2009, Version 1.1
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