pex-8512 PLX, pex-8512 Datasheet - Page 2

• Manufacturer Part Number: pex-8512
• Description: 12 Lane, 5 Port Pci Express Switch, 23 X 23mm Pbga
• Manufacturer: PLX

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.
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.
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.
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.
SerDes Power and Signal Management
The ExpressLane PEX 8512 supports software control of the
SerDes outputs to allow optimization of power and signal
Figure 1. Port Configurations
x4
PEX 8512
PEX 8512
PEX 8512
PEX 8512
x4
x4
x2 x2
PEX 8512
PEX 8512
x4
x4
x2
PEX 8512
PEX 8512
x2
x2
x4
x2
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 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.
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.
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.
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
Figure 2. Fan-in/out Usage