Patent ID: 6252790
Filing Date: 2001-06-26
Classification: G11C

Abstract:
A content-addressable memory (CAM) comprising:(a) a first memory cell storage partitioned into a plurality of blocks, each block containing a plurality of content words each stored entirely within the block, each content word consisting of a match portion and optionally a result portion, and the content words arranged in the blocks according to the values of their match portions;(b) a second memory cell storage containing values forming maxima for each block and minima for each next block, such that no content word stored in a block is greater than the value stored in the location in the second memory corresponding to that block nor smaller than the value stored in the location in the second memory corresponding to the next block;(c) an input interface receiving candidate values to be compared to the stored values in the first memory(d) a first logic device capable of determining a closest match among all the values stored in any given block in the first memory;(e) a second logic device capable of determining a closest match among all the values stored in the second memory;(f) a mechanism for selecting a block of the first memory based on the results of the second logic device, and reading the contents of the selected block into the first logic device; and(g) an output interface transmitting matched result values from the matched stored values in the first memory.