Version 1.4 2007
PEX 8524
Features
PEX 8524 General Features
o
24-lane PCI Express switch
-
Integrated SerDes
o
Up to six configurable ports
o
31mm x31mm, 644 pin PBGA package
o
Typical Power: 3.9 Watts
PEX 8524 Key Features
o
Standard Compliant
-
PCI Express Base Specification, r1.1
o
High Performance
-
Non-blocking switch fabric
-
Full line rate on all ports
o
Non-Transparent Bridging
-
Configurable Non-Transparent port
for Multi-Host or Intelligent I/O
Support
o
Flexible Configuration
-
Six highly flexible & configurable
ports (x1, x2, x4, x8, or x16)
-
Configurable with strapping pins,
EEPROM, or Host software
-
Lane and polarity reversal
o
PCI Express Power Management
-
Link power management states: L0,
L0s, L1, L2/L3 Ready, and L3
-
Device states: D0 and D3hot
o
Quality of Service (QoS)
-
Two Virtual Channels per port
-
Eight Traffic Classes per port
-
Fixed and Round-Robin Virtual
Channel Port Arbitration
o
Reliability, Availability,
Serviceability
-
6 Standard Hot-Plug Controllers
-
Upstream port as hot-plug client
-
Transaction Layer end-to-end CRC
-
Poison bit
-
Advanced Error Reporting
-
Lane Status bits and GPO available
-
Per port performance monitoring
•
Average packet size
•
Number of packets
•
CRC errors and more
-
JTAG boundary scan
Flexible & Versatile PCI Express Switch
Multi-purpose, Feature Rich
ExpressLane™
PCI Express Switch
The
ExpressLane
TM
PEX 8524 device offers PCI Express switching capability
enabling users to add scalable high bandwidth, non-blocking interconnection to a
wide variety of applications including
servers, storage systems, communications
platforms, blade servers,
and
embedded-control products.
The PEX 8524 is well
suited for
fan-out, aggregation, dual-graphics, peer-to-peer,
and
intelligent I/O
module
applications.
Highly Flexible Port Configurations
The
ExpressLane
PEX 8524 offers highly configurable ports. There are a maximum
of 6 ports that can be configured to any legal width from x1 to x16, in any
combination to support your specific bandwidth needs. The ports can be configured
for
symmetric
(each port having the same lane width and traffic load) or
asymmetric
(ports having different lane widths) traffic. In the event of asymmetric
traffic, the PEX 8524 features a
flexible central packet memory
that allocates a
memory buffer for each port as required by the application or endpoint. This buffer
allocation along with the device's
flexible packet flow control
minimizes
bottlenecks when the upstream and aggregated downstream bandwidths do not match
(are asymmetric). Any of the ports can be designated as the upstream port, which can
be changed dynamically.
End-to-end Packet Integrity
The PEX 8524 provides
end-to-end CRC
protection (ECRC) and
Poison bit
support
to enable designs that require
end-to-end data integrity.
These features are optional
in the PCI Express specification, but PLX provides them across its entire
ExpressLane
switch product line.
Non-Transparent “Bridging” in a PCI Express Switch
The
ExpressLane
PEX 8524 product supports full non-transparent bridging (NTB)
functionality to allow implementation of
multi-host systems
and
intelligent I/O
modules
in
communications, storage, blade server,
and
graphics fan-out
applications.
To ensure quick product migration, the non-transparency features are
implemented in the same fashion as in standard PCI applications.
Non-transparent bridges allow systems to isolate memory domains by presenting the
processor subsystem as an endpoint, rather than another memory system. Base
address registers are used to translate addresses; doorbell registers are used to send
interrupts between the address domains; and scratchpad registers are accessible from
both address domains to allow inter-processor communication.
Two Virtual Channels
The
ExpressLane
PEX 8524 switch supports 2 full-featured Virtual Channels (VCs)
and a full 8 Traffic Classes (TCs). The mapping of Traffic Classes to port-specific
Virtual Channels allows for different mappings for different ports. In addition, the
devices offer user-selectable Virtual Channel arbitration algorithms to enable users
to fine tune the Quality of Service (QoS) required for a specific application.
Low Power with Granular SerDes Control
The PEX 8524 provides low power capability that is fully compliant with the PCI
Express power management specification. In addition, the SerDes physical links can
be turned off when unused for even lower power.
PLX [ PLX TECHNOLOGY ]
