PEX 8680-AA50BC F PLX Technology, PEX 8680-AA50BC F Datasheet - Page 2

• Manufacturer Part Number: PEX 8680-AA50BC F
• Description: Peripheral Drivers & Components (PCIs) 80Ln/20Pt PCI Exprss Gen 2 (5 GT/s) Swtch
• Manufacturer: PLX Technology

Specifications of PEX 8680-AA50BC F

• Mounting Style: SMD/SMT
• Propagation Delay Time: 176 ns
• Package / Case: HFCBGA-1156
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The PEX 8680 can also be configured in Multi-Host
mode where users can choose up to six ports as
host/upstream ports and assign a desired number of
downstream ports to each host. In Multi-Host mode, a
virtual switch is created for each host port and its
associated downstream ports inside the device. The
traffic between the ports of a virtual switch is completely
isolated from the traffic in other virtual switches. Figure
2 illustrates some configurations of the PEX 8680 in
Multi-Host mode where each ellipse represents a virtual
switch inside the device.
The PEX 8680
also provides
several ways to
configure its
registers. The
device can be
configured
through
strapping pins,
I
host software,
an optional
serial
EEPROM.
This allows
for easy debug during the development phase,
performance monitoring during the operation phase, and
driver or software upgrade.
Dual-Host & Failover Support
In Single-Host mode, the PEX 8680 supports a Non-
Transparent (NT) Port, which enables the
implementation of dual-host systems for redundancy
and host failover capability.
The NT port allows systems
to isolate host memory
domains by presenting the
processor subsystem as an
endpoint rather than
another memory system.
address registers are used
to translate addresses;
doorbell registers are
used to send
interrupts between the
address domains; and scratchpad registers (accessible by
both CPUs) allow inter-processor communication (see
Figure 3).
© PLX Technology, www.plxtech.com
2
C interface,
Figure 2. Common Multi-Host Configurations
2 x8, 4 x4
x8
PEX 8680
PEX 8680
PEX 8680
PEX 8680
PEX 8680
PEX 8680
PEX 8680
PEX 8680
4 x4s
16 x4s
Point
Point
Point
Point
Point
Point
Point
Point
Figure 3. Non-Transparent Port
Figure 3. Non-Transparent Port
End
End
End
End
End
End
End
End
2 x8, 4x4
x8
PEX 8680
PEX 8680
PEX 8680
PEX 8680
Primary Host
Primary Host
Primary Host
Complex
Complex
Complex
Complex
Complex
Complex
Primary Host
Primary Host
Primary Host
Point
Point
Point
Point
Point
Point
Point
Point
Root
Root
Root
Root
Root
Root
CPU
CPU
CPU
CPU
CPU
CPU
End
End
End
End
End
End
End
End
PEX 8680, PCI Express Gen 2 Switch, 80 Lanes, 20 Ports
4 x4
NT
NT
x8
PEX 8680
PEX 8680
PEX 8680
PEX 8680
PEX 8680
PEX 8680
PEX 8680
PEX 8680
6 x4s
4 x4
Point
Point
Point
Point
Point
Point
Point
Point
12 x4s
End
End
End
End
End
End
End
End
x8
Secondary Host
Secondary Host
Secondary Host
Secondary Host
Secondary Host
Secondary Host
Non-Transparent
Non-Transparent
x8
4 x4
CPU
CPU
CPU
CPU
CPU
CPU
Port
Port
Base
or
Page 2 of 2
Multi-Host & Failover Support
In Multi-Host mode, PEX 8680 can be configured with
up to six upstream host ports, each with its own
dedicated downstream ports. The device can be
configured for 1+1 redundancy or N+1 redundancy. The
PEX 8680 allows the hosts to communicate their status
to each other via special door-bell registers. In failover
mode, if a host fails, the host designated for failover will
disable the upstream port attached to the failing host and
program the downstream ports of that host to its own
domain. Figure 4a shows a two host system in Multi-
Host mode with two virtual switches inside the device
and Figure 4b shows Host 1 disabled after failure and
Host 2 having taken over all of Host 1’s end-points.
Hot Plug for High Availability
Hot plug capability allows users to replace hardware
modules and perform maintenance without powering
down the system. The PEX 8680 hot plug capability
feature makes it suitable for High Availability (HA)
applications. Four downstream ports include a Standard
Hot Plug Controller. If the PEX 8680 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 8680 is
equipped with a hot-plug control/status register to
support hot-plug capability through external logic via the
I
SerDes Power and Signal Management
The PEX 8680 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 management of the entire system.
Interoperability
The PEX 8680 is designed to be fully compliant with the
PCI Express Base Specification r2.0, and is backwards
compatible to PCI Express Base Specification r1.1 and
Point
Point
Point
Point
2
End
End
End
End
Figure 4a. Multi-Host
C interface.
Host 1
Host 1
Host 1
Host 1
PEX 8680
PEX 8680
Point
Point
Point
Point
End
End
End
End
Point
Point
Point
Point
End
End
End
End
Host 2
Host 2
Host 2
Host 2
Point
Point
Point
Point
End
End
End
End
Figure 4b. Multi-Host Fail-Over
Point
Point
Point
Point
End
End
End
End
Host 1
Host 1
Host 1
Host 1
PEX 8680
PEX 8680
Point
Point
Point
Point
End
End
End
End
Point
Point
Point
Point
End
End
End
End
5/14/2009, Version 1.1
Host 2
Host 2
Host 2
Host 2
Point
Point
Point
Point
End
End
End
End