Method and device null multiple - level hierarchical associative memory in order to make

摘要

PROBLEM TO BE SOLVED: To reduce power consumption in a multi-level hierarchical content addressable memory (CAM) circuit without adversely impacting performance.;SOLUTION: A CAM circuit comprises: a plurality of lower-level match lines; a plurality of higher-level match lines; and match line restoration circuitry. The lower-level match lines are configured to be restored to a pre-evaluation state during a pre-evaluation period. The higher-level match lines are configured to capture an evaluation state of respective groups of one or more of the lower-level match lines during an evaluation period, and to be restored to a pre-evaluation state during the pre-evaluation period. The match line restoration circuitry is configured to prevent at least one of the lower-level match lines from being restored to the pre-evaluation state in response to corresponding enable information, e.g., one or more bits indicating whether match line search results are to be utilized.;COPYRIGHT: (C)2013,JPO&INPIT