Content addressable memory device
View Patent ↗The range-specified IP addresses are effectively stored to reduce the number of necessary entries thereby the memory capacity of TCAM is improved. The representative means of the present invention is that: the storage information (entry) and the input information (comparison information or search key) are the common block code such that any bit must be the logical value ‘1’; Match-lines are hierarchically structured and memory cells are arranged at the intersecting points of a plurality of sub-match lines and a plurality of search lines; Further the sub-match lines are connected to main-match lines through the sub-match detectors, respectively and main-match detectors are arranged on the main-match lines.
1. An information search system comprising a processor, a search device and a content memory, wherein
the processor is connected to the search device through a data bus and to the content memory through a content bus,
the search device and the content memory are connected to each other through a content memory address bus, and
the search device converts a first information and a second information into a common block code for comparison such that at least one bit is a logical value ‘1’.
2. The information search system according to claim 1 ,
wherein the search device comprises a plurality of bit lines arranged in a first direction, a plurality of word lines arranged in a second direction orthogonal to the first direction, a plurality of main-match lines arranged in the second direction, a plurality of sub-match lines arranged in the second direction such that each sub-match line is paired with an associated one of the main-match lines, and memory cells arranged at respective intersecting points of the plurality of bit lines with the plurality of word lines, wherein the memory cells are connected to corresponding ones of the plurality of sub-match lines.
3. The information search system according to claim 2 , wherein the processor shares information regarding the first information with the search device through an entry count signal.