Design And Implementation For TCAM Complier Based On Java

CAM(Content Addressable Memory),the stored value can only be “0” or “1”,can achieve the function of comparing all stored data with the data to be searched on the same clock edge,are widely used in data link layer,network layer equipment in computer network technologies.In order to achieve fuzzy matching search needs,on basis of CAM technology,comes the TCAM(Ternary Content Addressable Memory),TCAM can not only save "0","1",but also stored value "X",which means no relationship.TCAM technologies are widely used in routing table forwarding,fast access to ACL and other scenes.The development of TCAM technology is accompanied by two mutually constrained factors: speed and power consumption.And the main design goals are high-speed and low-power consumption at the same time.In order to meet the ever-changing memory chip market demand,accelerate the cycle of development and production of memory chips,here comes the complier technology which can use the computer language manipulate the circuit directly,such as the famous SRAM(Static Random Access Memory)Compiler.In view of the TCAM's great influence in network communication and TCAM circuit itself has a relatively fixed structure to achieve the basis of modular development,it is necessary to draw on the compiler technology used by SRAM for rapid development.In this paper,the basic theory of TCAM and the theory of each sub-circuit of complete TCAM chip are studied.Then design the schematic,layout of each part which can through the post simulation.And then the TCAM compiler software was developed based on Java language which can generate layout files,netlist files,LEF files,Verilog files,Verilog tb demo files automatically.In process of splicing layout,this paper reduces the GDS file's size and improves the read rate significantly by using array-splicing method directly;When splicing the MMR(Multiple-Matches Range)cell,this paper uses a multi-level distribution method,distribute parasitic parameters evenly and stable the chip performance.After verification,the software can produce the required circuit correctly and efficiently and with good portability in view of the features of the object-oriented Java language,which can be applied to different TCAM development scenarios with minor modifications.