PEX8525 Datasheet, PDF (1/4 Pages) PLX Technology – High-Performance 24-lane, 5-port PCIe Switch

Version 1.2 2007
Features
ƒ PEX 8525 General Features
o 24-lane PCI Express switch
- Integrated SerDes
o Up to five configurable ports
(x1, x2, x4, x8, x16)
o 31mm x31mm, 644-ball PBGA package
o Typical Power: 2.6 Watts
ƒ PEX 8525 Key Features
o Standard Compliant
- PCI Express Base Specification, r1.0a
o High Performance
- Non-blocking switch fabric
- Full line rate on all ports
- Packet Cut-Thru with 115ns max
packet latency (x8 to x8)
o Flexible Configuration
- Five highly flexible & configurable
ports (x1, x2, x4, x8, or x16)
- Configurable with strapping pins,
EEPROM, I²C, 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)
- One Virtual Channel per port
- Eight Traffic Classes per port
- Weighted Round-Robin Ingress Port
Arbitration
o Reliability, Availability, Serviceability
- 3 Standard Hot-Plug Controllers
- Upstream port as hot-plug client
- Transaction Layer end-to-end CRC
- Poison bit
- INTA# interrupt signal
- Fatal Error (FATAL_ERR#) signal
(legacy SERR equivalent)
- PCIe baseline error reporting
- Advanced Error Reporting
- Port Status bits and GPO available
- Per port error diagnostics
• Bad DLLPs
• Bad TLPs
• CRC errors
- JTAG boundary scan
PEX 8525
High-Performance 24-lane, 5-port PCIe Switch
Multi-purpose, High Performance ExpressLane™ Switch
The ExpressLane PEX 8525 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 8525 is well suited for fan-out, aggregation, dual-
graphics, peer-to-peer, and intelligent I/O module applications.
Highly Flexible Port Configurations
The PEX 8525 offers highly configurable ports. There are a maximum of 5
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 8525 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.
High Performance
The PEX 8525 architecture supports packet cut-thru with a max latency of
115ns (x8 to x8). This, combined with large packet memory (1024 byte
maximum payload size) and non-blocking internal switch architecture,
provide full line rate on all ports for performance-hungry applications such as
storage servers or storage switch fabrics.
End-to-end Packet Integrity
The PEX 8525 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.
Configuration Flexibility
The PEX 8525 provides several ways to configure its operations. The device
can be configured through strapping pins, I²C interface, CPU configuration
cycles, or an optional serial EEPROM. This allows for easy debug during the
development phase, performance monitoring during the operation phase, and
driver or software upgrade.
Interoperability
The PEX 8525 is designed to be fully compliant with the PCI-SIG revision
1.1 specification. Additionally, it supports auto-negotiation, lane reversal,
and polarity reversal. The PEX 8525 also undergoes thorough
Interoperability testing in PLX’s Interoperability Lab.
PLX Confidential