Port Configurations
The lane width of each port can be individually configured
through auto-negotiation, hardware strapping, host software
configuration, I
2
C interface, or through an optional EEPROM.
The PEX 8505 supports three port configurations:
1) One x1 upstream port and four x1 downstream ports
2) One x2 upstream port and three x1 downstream ports
3) One x2 upstream port, one x2 downstream port, one x1
downstream port
SerDes Power and Signal Management
The ExpressLane PEX 8505 supports
software control
of the
SerDes outputs
to allow optimization of power and signal
strength in a system. The PLX SerDes implementation
supports four levels of power – off, low, typical, and high. The
SerDes block also supports
loop-back modes
and
advanced
reporting of error conditions,
which enables efficient debug
and management of the entire system.
Port Arbitration
The PEX 8505 switch supports hardware fixed and
Weighted
Round-Robin Ingress Port Arbitration.
This allows fine
tuning of Quality of Service and efficient use of packet buffers
and the system bandwidth.
x1
PEX 8505
Applications
Suitable for
control plane applications, multi-function
printers, DVRs, industrial control systems, medical
imaging systems, embedded systems & AMC modules,
the
PEX 8505 can be configured for a wide variety of form factors
and applications.
x1 x1 x1 x1
Control Plane Application
x1
x2
PEX 8505
PEX 8505
The PEX 8505 is ideal for migrating existing PCI control
planes in routers to high-speed PCI Express interface to meet
increased packet processing needs. Figure 2 shows a controller
card with a PEX 8505 connecting the Control Processor to as
many as four devices each via a x1 port. This usage model
provides connectivity to multiple devices giving the processor
control over multiple devices in mid-range routers.
ASIC
FPGA
x1 x1 x1
x2
x1
FPGA
PEX 8505
Figure 1. Port Configurations
Hot-Plug for High Availability
Hot-Plug capability allows users to replace hardware modules
and perform maintenance without powering down the system.
The PEX 8505
Hot-Plug
capability and
Advanced Error
Reporting
features make it suitable for
High Availability
(HA) applications.
Ports 1, 2 & 3 include a
Standard Hot-
Plug Controller.
If the PEX 8505 is used in an application
where one or more of its downstream ports connect to PCI
Express slots, Hot-Plug Controllers on the three downstream
ports can be used to manage the hot plug event of its
associated slot.
Control
Processor
Memory
ASIC
Figure 2. Control Plane
I/O Expansion
The PEX8505 can be used in I/O expansion applications.
Together with a PCI Express-to-PCI bridge, the PEX8505 is
capable of providing legacy PCI I/O expansion support. Each
x1 port in the PEX8505 provides 250MB/s bandwidth per
direction and it is more than capable of supporting the various
bus widths and bus speeds of legacy PCI. Please visit the
www.plxtech.com/bridges
for additional information on
PLX’s PCI Express bridge family.
Fully Compliant Power Management
For applications that require power management, the
ExpressLane PEX 8505 devices support both link (L0, L0s,
L1, L2/L3 Ready and L3) and device (D0 and D3hot) power
management states, in compliance with the PCI Express power
management specification.
www.plxtech.com
PLX [ PLX TECHNOLOGY ]
