Hash-based method for searching CAM (central address memory)

A look-up table and bus technology, applied in special data processing applications, instruments, electrical digital data processing, etc., can solve problems such as low efficiency of software search and matching, high-speed network powerlessness, etc., to achieve fast search, reduce the number of comparisons, and improve throughput rate effect

Active Publication Date: 2012-02-29
LANGCHAO ELECTRONIC INFORMATION IND CO LTD
View PDF3 Cites 22 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

With the development of network technology, these key network technologies all involve search and match problems, but the efficiency of search and ma

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Hash-based method for searching CAM (central address memory)
  • Hash-based method for searching CAM (central address memory)

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0033] 1) Use Hash to find the existing form of the function, including: direct method, subtraction method, remainder method, value extraction method, intermediate average method, folding method, rotation method, pseudo-random number method, design and modeling adopts top-down The analysis and design method of the whole system is divided into multiple modules, and each module is further refined until the lowest level is used for coding, and the development and debugging of the underlying modules are carried out one by one, and then the modules are jointly debugged, and finally the whole system is linked tone;

[0034] 2) For the Hash collision problem in Hash lookup, the solutions include: (1) linear open addressing method; (2) difference solution; (3) linked list solution; (4) bucket Hash method;

[0035] 3) The CAM-based memory bank not only has data storage capability, but also has data comparison capability. The memory bank receives the comparison data and broadcasts it to...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a hash-based method for searching a CAM (central address memory). The CAM has a data storage function and a high-speed data content searching function and also supports multiple instructions such as reading, writing and searching. However, the most important function of the CAM is the high-speed data content searching function, and the searching function is based on other functions of the CAM. Therefore, the core of the design of a CAM functional model is the design of a high-speed searching engine. The searching engine can maintain a sheet and receive external input data. The input data and each item in the sheet are completely compared (accurate) or partially compared (Don'tcare function) through a certain search algorithm in the searching engine, and then comparison results are output. The rapid CAM content search can be achieved via a hash function. When a request is searched through the CAM, hash calculation is carried out for data to be searched to obtain a hashkey, a first address of a CAM table item data linked list is obtained via access to a hash entry table according to the hashkey (as a hash entry table address), the access to the CAM data table item linked list is completed, the data to be searched and items in the CAM data linked list are compared one by one, and finally CAM search results are returned.

Description

[0001] technical field [0002] The invention relates to the technical fields of communication, data searching and matching under high-speed network or chip design, and specifically relates to a method for searching CAM based on Hash. Background technique [0003] With the rapid development of communication technology, on the one hand, the data bandwidth transmitted in the network is getting larger and larger. On the other hand, various applications in the network are constantly changing and developing. The current IP network needs to provide users with more service types and better service quality, requiring routers to provide additional processing mechanisms to achieve differentiated services. Classification, security intrusion monitoring, firewall access control, virtual private network, fast route lookup, network address translation, and some other key network technologies. [0004] In order to adapt to the growing trend of network data traffic and ensure the smoothness...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G06F17/30
Inventor 周恒钊
Owner LANGCHAO ELECTRONIC INFORMATION IND CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap