Flexible Port Width Configuration
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 8533 supports a large number of port
configurations. For example, if you are using the PEX
8533 in a fan-out application, you may configure the
upstream port as a x8 and the downstream as one x8 port
& four x4 ports; two x8 & two x4 ports; or other
combinations, as long as you don’t run out of lanes (32)
or ports (6). For a
dual-graphics application,
you may
configure the device as one x16 upstream and two x8
downstream ports (see Figure 1). The device can also
support x2 & x1 ports by auto-negotiating its x4 ports to
the width of the actual end-device it is interfacing with.
application where one or more of its downstream ports
connect to PCI Express slots, the ports with the Hot Plug
Controller feature can be used for these slots. The device
will automatically manage the hot-plug event of its hot-
plug capable ports/slots. Furthermore, the hot-plug
capable ports can be used as a
hot-plug client or
master,
allowing it to be
used on hot-pluggable carrier
modules, backplanes, and fabric modules.
Fully Compliant Power Management
For applications that require power management, the
PEX 8533 device supports 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.
SerDes Power and Signal Management
The ExpressLane PEX 8533 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.
Applications
Suitable for
host-centric
as well as
peer-to-peer
traffic
patterns, the PEX 8533 can be configured for a wide
variety of form factors and applications.
Host Centric Fan-out
The ExpressLane PEX 8533 device, with its versatile
symmetric or asymmetric lane configuration capability,
allows for user specific tuning to a variety of host-
centric applications.
Figure 1. Port Flexibility
Low Packet Latency
The PEX 8533 supports packet cut-through with a
latency of 115ns between symmetric x8 ingress and
egress ports. The low latency enables many applications
to achieve high throughput and performance. In addition
to low latency, the device supports a packet payload size
of up to 1024 bytes, enabling the user to achieve even
higher throughput.
Hot Plug for High Availability
Hot plug capability allows users to replace hardware
modules and perform maintenance without powering
down the system. The ExpressLane PEX 8533 hot plug
capabilities and
Advanced Error Reporting
features
make them suitable for
high availability (HA)
applications.
Three of the six ports include a
Standard
Hot Plug Controller.
If the PEX 8533 is used in an
Figure 2. Fan-in/out Usage
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