21555 Non-Transparent

PCI-to-PCI Bridge

Revolutionary Bridge Technology for Intelligent I/O

and Embedded Applications

Intel’s 21555 Non-Transparent PCI-to-PCI

bridge chip enables add-in card vendors to

deliver high-performance, intelligent option

cards and embedded products that previously

were not possible. Designed specifically for

applications where a processor is used behind a

PCI-to-PCI bridge, the 21555 provides a clean

architecture for creating a product with multiple

processor domains.

Product Highlights

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Non-Transparent PCI-to-PCI bridge

technology for high-performance embedded

and intelligent I/O applications

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Independent address spaces and asynchronous

clocks deliver unparalleled application

flexibility

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64-bit primary and secondary bus interfaces

deliver high performance for data-intensive

applications

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Compliant with ACPI and PCI bus power

management specifications

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Secondary bus arbitration support for up to

nine bus master devices

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Evaluation Design Kit speeds time-to-market

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Fully compliant with Revision 2.

3 of the PCI

specification including delayed transactions

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Available in 33 and 66 MHz

product brief

Product Overview

Efficient Management of System and

Subsystem Resources

A Unique Bridge Architecture

developer.intel.com

The 21555 provides independent primary and

secondary address spaces, which allow

independent host and local address mapping.

With this key feature, local memory requirements

need not impact the host address map. The 21555

performs address translation between the primary

and secondary buses, resolving address resource

conflicts between the host and local address

domains.

Featuring a subsystem PCI configuration

boundary, the 21555 allows the local processor to

have complete PCI configuration control of

subsystem devices, without host interference. This

advanced feature also allows the 21555 to present

a subsystem, such as a RAID controller, as a

single virtual PCI device. An added benefit of

this design is the ability to easily identify a single

device driver for the entire subsystem. Another

feature of the 21555, a serial ROM interface,

allows manufacturers to customize the 21555 for

a particular application by pre-loading the ROM

with vendor-specific configuration data.

Intel’s 21555 is a unique new Non-Transparent

PCI-to-PCI bridge solution. The 21555 provides

designers of intelligent controllers and

embedded systems with a Non-Transparent PCI-

to-PCI bridge solution capable of resolving

resource conflicts between a PCI-based host

system and a PCI-based subsystem. This gives a

local processor maximum flexibility in mapping

and managing subsystem resources.