fast, and dependable means of powering down unused database tables. This way a highly structured and partitioned CAM will only keep the portion that contains the currently used tables active. This expected to minimize power consumption. Last but not least, CAM vendors are struggling to make their products easily usable by their cus- tomers. Users come from various camps. Some of them are proponents of the highest possible per- formance and are ASIC driven. Others are proponents of flexible network processors instead. CAM External External Embedded Embedded Memory Interface Memory arbiter Up to 64 LEs Distributor Collector VCI Interface ClearConnectTM bus FIGURE 12.6 An example of an implementation of the ClearSpeed TLE using both embedded and external RAM. (Source: ClearSpeed Technology, Ltd.) Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. SEARCH ENGINES 234 NETWORK PROCESSORS designers find themselves between a rock and a hard place as they try to please as many potential cus- tomers as possible. The proprietary interfaces to each CAM are rapidly becoming a context of the past. Consequently, more CAM vendors take pride in announcing that their latest designs allow glue- less interface with most mainstream network processors such as AMCC and Intel. ALTERNATIVE WAYS OF IMPLEMENTING A SEARCH ENGINE A very elegant and highly scalable way of handling up to 1 billion searches per second without the use of CAM is the approach taken by ClearSpeed Technology in the implementation of their Table Lookup Engine (TLE) intellectual property (IP) core. We have already discussed in Chapter 10, "Alternative Approaches to Network Processing: Net ASICs and Designing with IP Cores," ClearSpeed's approach to the implementation of a powerful network-processor platform that addresses the evolving wire speeds by deploying a massively paral- lel computation soluti