Design And Achieve High-Performance TCAM With Very Deep-Submicron Technics

Internet information technology has developed rapidly in just few decades.The scale of internet terminal and information become larger and larger,and the construction of information become more and more complicated.The matching methods existing can't afford the demand of fast and accurate matching,gradually.The researchers come up with a new matching method based on the hardware for the development of matching demand.Compare with the CAM which is accurate matching,TCAM(Ternary Content Addressable Memory)has the third state "don't care",besides "0" and "1".That means TCAM can match not only precisely,but also fuzzy.This expands the region of TCAM application largely.However,with the development of internet,the scale of data larger and larger,people need higher performance TCAM to satisfy practical demands.Within this context,this paper proposed a new TCAM circuit construction,HP-TCAM.At first,we changed the construction of the traditional TCAM bit-cell,proposed a barrel structure bit-cell.This bit-cell has good symmetrical characteristic and anti-interference ability.Then,this paper came up with a NOR-type Match Line circuit with two-level compare circuit.And then,the paper designed an input circuit with the transfer circuit which can transfer the searching-signal as dynamic signal because the different of searching-signal,driver-circuit,tree-type clock circuit and static pre-decoder circuitFinally,based on the ways mentioned above,the paper devised a HP-TCAM layout with 12 8-entry x 128-bits by very deep-submicron technics,and simulated it with simulator.The circuit's timing cycle is 0.4ns,and the searching speed achieves at 0.21ns with typical technics.The circuit's layout is just 20381?m12,power consumption is 2.6fj/bit/search.