Low Power with Granular SerDes Control
The PEX 8512 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.
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.
Flexible Port Width Configuration
The lane width for each port can be individually configured
through auto-negotiation, hardware strapping, upstream
software configuration, or through an optional EEPROM.
The PEX 8512 supports two port configurations as shown in
Figure 1. Depending on the application, the PEX 8512 can be
configured to have Three ports each with x4 link widths or
Five ports one port with x4 link width and four ports with x2
link widths.
x4
x4
Flexible Virtual Channel Arbitration
The
ExpressLane
PEX 8512 switch supports
hardware fixed
and Round Robin arbitration schemes
for two virtual
channels on each port. This allows for the fine tuning of
Quality of Service for efficient use of packet buffers and
system bandwidth.
Applications
Suitable for
host-centric
as well as
intelligent I/O
applications
ExpressLane
PEX 8512 can be configured for a
wide variety of form factors and applications.
PEX 8512
PEX 8512
Host-Centric Fan-out
The
ExpressLane
PEX 8512 switch, with its symmetric lane
configuration capability, allows user specific tuning to a
variety of
host-centric as well as peer-to-peer applications.
x4
x4
x2 x2 x2 x2
x4
PEX 8512
x2 x2
x4
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 8512 hot-plug capability and
Advanced Error
Reporting
features makes it suitable for
High Availability
(HA) applications.
Three downstream ports include a
Standard Hot-Plug Controller. If the PEX 8512 is used in an
application where one or more of its downstream ports
connect to
PCI Express slots, the port’s Hot-Plug Controller can be used
to manage the hot-plug event of its associated slot.
Furthermore, its upstream port is a
hot-plug client,
allowing it
to be
used on hot-pluggable adapter cards, backplanes, and
fabric modules.
Figure 2. Fan-in/out Usage
Figure 2 shows a typical
server-based
design, where the root
complex provides a PCI Express link that needs to be fanned
into a larger number of ports for a variety of I/O functions,
each with different bandwidth requirements.
In this example, the PEX 8512 would typically have a 4-lane
upstream port, and two downstream ports. The downstream
ports are configured with x4 link widths.
Fully Compliant Power Management
For applications that require power management, the
PEX 8512 device supports both link (L0, L0s, L1, L2/L3
Ready, L2 and L3) and device (D0 and D3hot) power
management states, in compliance with the PCI Express power
management specification.
Adapter Card Aggregation
The number and variety of PCI Express native-mode devices
is growing quickly. As these devices become mainstream, it
will be necessary to create multifunction and multi-port
adapter cards with PCI Express capability. The PEX 8512 can
be used to create an adapter or mezzanine card that aggregates
the PCI Express devices into a single port that can be plugged
SerDes Power and Signal Management
The ExpressLane PEX 8512 supports
software control
of the
SerDes outputs
to allow optimization of power and signal
PLX [ PLX TECHNOLOGY ]
