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Network Search Engine 32K x 72 Entries

Datasheet Brief 75N43102

Registers

There are three basic types of registers supported:

segmentation of the entries.

instructions by masking individual bits during a search.

Functional Highlights

Figure 1.1

Bus Interface

The NSE utilizes a dual bus interface consisting of the NSE Request

Bus and the NSE Response Bus.

The NSE Request Bus is comprised of the Command Bus and the

RequestDataBus. TheCommandBushandlestheinstructiontotheNSE

while the Request Data Bus is the main data path to the NSE.

The72bitbi-directionalRequestDataBusfunctionsasamultiplexed

address and data bus, which performs the writing and reading of NSE

entries, as well as presenting lookup data to the device.

The NSE Response Bus is comprised of an independent unidirec-

tionalIndexBuswhichdrivestheresultofthelookup(orindex) to anASIC.

Data and Mask Array

The NSE has Data cell entries and associ-

atedMaskcellentriesasshowninFig.1.1. This

combination of Data and Mask cell entries en-

ables the NSE to store 0, 1 or X, making it a full

ternary Network Search Engine. During a

lookup operation, both arrays are used along

with a Global Mask Register to find a match to a

requested data word.

A 6435 drw 03

Dat a

Mask

Command Bus

TheCommandBusloadsthe specificinstructionsintotheNSE.These

include:

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Read or Write

A Read or Write instruction operates on a specified data entry, mask

entry, or register.

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Lookup

A lookup can be requested in 72-bit, 144-bit or 288-bit widths. A 36-

bit lookup can be accomplished by using two Global Mask Registers.

Features

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Full Ternary 32K x 72 bit content addressable memory

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Global Mask Registers

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72/144/288 multiple width lookups

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62.5M sustained lookups per second at 72 and 144 width lookups

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Dual bus interface

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Cascadable to 2 devices with no glue logic or latency penalty

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Boundary Scan JTAG Interface (IEEE 1149.1compliant)

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1.5V match power supply

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2.5V core and I/O power supply