Hot-Plug for High Availability
Hot-Plug capability allows users to replace hardware modules
and perform maintenance without powering down the system.
The PEX 8604 Hot-Plug capability feature makes it suitable
for High Availability (HA) applications. If the PEX 8604 is
used in an application where one or more of its downstream
ports connect to PCI Express slots, each port’s Hot-Plug
Controller can be used to manage the Hot-Plug event of its
associated slot. Every port on the PEX 8604 is equipped with
a Hot-Plug control/status register to support Hot-Plug
capability through external logic via the I2C interface.
Dual Cast
The PEX 8604 supports Dual Cast, a feature which allows for
the copying of data (e.g. packets) from one ingress port to two
egress ports allowing for higher performance in storage,
security, and mirroring applications.
Read Pacing
The Read Pacing feature allows users to throttle the amount of
read requests being made by downstream devices. In the case
where a downstream device requests several long reads backto-
back, the Root Complex gets tied up in serving this
downstream port. If this port has a narrow link and is therefore
slow in receiving these read packets from the Root Complex,
then other downstream ports may become starved – thus,
impacting performance. The Read Pacing feature enhances
performances by allowing for the adequate servicing of all
downstream devices by intelligent handling of read requests.
SerDes Power and Signal Management
The PEX 8604 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. The PEX 8604
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 and Virtual Channel (VC) Arbitration
The PEX 8604 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 for
better system performance. The PEX 8604 also supports WRR
VC arbitration scheme between the two virtual channels.
Applications
Suitable for fan-out, control plane applications, embedded
systems as well as intelligent I/O applications, PEX 8604
can be configured for a wide variety of form factors and
applications.
Fan-Out
The PEX 8604 switch, with its flexible configurations, allows
user specific tuning to a variety of host-centric as well as
peer-to-peer applications.