Version 1.0 2004
PEX 8111
ƒ General Features
o Forward and Reverse bridging
o Tiny 161 ball BGA package
(10mm x 10mm)
o Low power – 0.3 Watts maximum
o EEPROM configuration option with
o Internal 8Kbyte shared RAM
o 1.5 V core supply voltage
o Four (4) GPIO pins for maximum
design and application flexibility
o Extensive PME support including
D0 and D0Active, D1, D2 and D3Hot
and D3Cold
ƒ Integrated PCI Express Interface
o PCI Express Base specification 1.0a
o x1 Link, full-duplex, 2.5 Gbps
o One virtual channel
o Automatic LVDS polarity reversal
o 128 byte maximum payload size
o Link CRC
o Link power management
o Flow control buffering
o PCI Express transaction queues for
eight (8) outstanding TLPs
ƒ PCI Interface
o PCI 3.0: 32 bits at 33 MHz
o PCI Power Management 1.1
o Internal arbiter supports up to 4
external masters; provides
REQ#/GNT# signals
o 3.3V I/O and 5V tolerant PCI
o Message Signal Interrupt (MSI)
o Provides PCI clock output
o Four mailbox registers for messaging
o ISA Enable and VGA Enable
registers for legacy operation
PCI Express to PCI Bridge
Reversible Bridge in a Tiny Package
The PLX Technology PEX 8111 bridge enables designers to migrate legacy PCI bus
interfaces to the new advanced serial PCI Express. This is ideal when including
existing PCI ICs on a PCI Express™ Adapter Board, such as the new ExpressCard™
standard. This simple bridge can also reside on either end of a PCI Express cable to
connect remote functions running the PCI protocol. The PEX 8111 supports
forward and reverse bridging. The tiny 10 mm x 10mm Plastic BGA package
makes the PEX 8111 bridge ideal for use in applications where board real estate is at
a premium. With its low power 0.15 micron CMOS design, the PEX 8111 consumes
a maximum power of only 300 mW.
Forward and Reverse Bridging
Compliant to the PCI Express-to-PCI/PCI-X Bridge Specification 1.0, the PEX 8111
is capable of operating in either forward or reverse bridging modes. In forward
mode, the bridge allows legacy PCI chips and adapters to be used with new PCI
Express processor systems. Reverse bridge operation allows conventional PCI
processors and chipsets to configure and control advanced PCI Express switches and
endpoints. The reverse PEX 8111 not only allows complete configuration of a
downstream PCI Express system from the PCI bus, but it also handles limited
PCI Express root functions for reverse interrupt and Power Management Events.
Block Diagram
The PEX 8111 is equipped with a
standard PCI Express port that operates
as a single, x1 link with a maximum of
250 Megabytes per second of throughput
per transmit and receive direction. With a
single 2.5 Gbps integrated SerDes, the
standard PCI Express signaling delivers
the highest bandwidth with the lowest
possible pin count using LVDS
The PEX 8111 has a single parallel bus
segment supporting the PCI v 3.0
protocol. With a 32-bit wide parallel data
path running at 33MHz, the PCI
bandwidth is 132 Megabytes per second.
While the PCI Express link
accommodates the full PCI bus
bandwidth, the device also supports
internal queues with flow control features
to optimize throughput and traffic flow.
PCI Bus (32 Bit, 33 MHz)
PCI Master and Target Interface Logic
8K Shared
PCI Express Transaction Layer
(Packet Construction Logic)
PCI Express Data Link Layer
PCI Express PHY Layer
PCI Express Link (1 lane, 1 Virtual Channel, 2.5 GHz)
Figure 1. PEX 8111 Block Diagram
Design Applications
ExpressCard™ Adapter – Forward Bridge
Standardized PCI Expansion – Forward and
Reverse Bridge Modes
The PEX 8111 is the ideal bridge for facilitating remote I/O
expansion in computing, communications, or data acquisition
applications (see Figure 4). The PCI SIG® PCI Express
cabling specification and the PEX 8111 offer a standardsbased extender for the parallel PCI bus. Because the
PEX 8111 supports reverse bridging operation, the PCI host
system is able to configure the PCI Express link.
The PEX 8111 can be used to quickly upgrade legacy PCI
adapter board designs to be compatible with PCI Express
standard interface slots. In Figure 2, an existing CardBus™ IC
is converted for use on an ExpressCard™ with the addition of
the single-chip PEX 8111.
Figure 2. Forward Bridge in ExpressCard™
PCI Express
Embedded Platform – Reverse Bridge
The PEX 8111 supports Reverse bridging, enabling designers
to utilize the latest PCI Express silicon with widely entrenched
PCI host systems. Reverse bridging allows the host processor
to reside out on the PCI bus; the PEX 8111 will accept
configuration cycles from the PCI side and manage the local
PCI Express interface as a secondary entity within the PCI
software model as in Figure 3.
PCI Slots
Figure 4. Remote Expansion of PCI-Based Systems
Development Tools
PCI Express
PCI-to-PCI Express
PEX 8111 Reference Design Kits (PEX 8111RDKs) enable
rapid customer design. The Forward Bridge RDK hardware
module includes the PEX 8111 with a single x1 PCI Express
(card-edge) port and single PCI slot on the secondary side.
The Reverse Bridge RDK includes a standard PCI edge
connector (card-edge) and a standard PCI Express slot on the
secondary side. Each PEX 8111RDK can be installed in a
motherboard to test and validate customer software and to
evaluate PEX 8111 features and benefits.
Figure 3. Reverse Bridge with PCI CPU
Product Ordering Information
PLX Technology, Inc.
870 Maude Ave.
Sunnyvale, CA 94085 USA
Tel: 1-800-759-3735
Tel: 1-408-774-9060
Fax: 1-408-774-2169
Email: [email protected]
Web Site:
Part Number
PEX 8111-AA33BC
PCI Express to PCI Bridge
Forward Bridge Reference Design Kit
Reverse Bridge Reference Design Kit
Please visit the PLX Web site at http://www plxtech com or contact PLX sales at 408-774-9060 for sampling
© 2004 PLX Technology, Inc. All rights reserved. PLX and the PLX logo are registered trademarks of PLX Technology, Inc. All other product names that appear in this material are for
identification purposes only and are acknowledged to be trademarks or registered trademarks of their respective companies. Information supplied by PLX is believed to be accurate and reliable,
but PLX Technology, Inc. assumes no responsibility for any errors that may appear in this material. PLX Technology, Inc. reserves the right, without notice, to make changes in product design or
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