Patent Number: 6,252,789

Title: Inter-row configurability of content addressable memory

Abstract: A CAM system for storing a data word chain having a sequence of one or more data words stored in one or more rows of CAM cells. For one embodiment, the CAM system includes rows of CAM cells each for storing a data word in a data word chain, match lines, and width expansion logic circuits each having a plurality of control inputs for receiving a plurality of control signals. The width expansion logic circuits are interconnected and determine when and how match results are communicated to a priority encoder and to each other. The control signals are for determining the operation of the width expansion logic circuits and for indicating when a first data word, a continuing data word, and a last data word of the data word chain are provided for comparison with the rows of CAM cells. The continuing data word is a data word between the first and last data word in the data word chain. For one embodiment, the control signals are generated by an instruction decoder in response to decoding separate instructions for comparing the first data word, a continuing data word, and the last data word of a data word chain. Each row of CAM cells may also include classification information or control bits that indicate the data word chain or the place of a data word in the data word chain. For one embodiment, the CAM system can store and operate on data word chains of different lengths.

Inventors: Pereira; Jose Pio (Santa Clara, CA), Srinivasan; Varadarajan (Los Altos Hills, CA)

Assignee: NetLogic Microsystems, Inc.

International Classification: G06F 17/30 (20060101); G11C 15/00 (20060101); G11C 015/00 ()

Expiration Date: 06/26/2018