Vertically Partitioned SRAM-Based Ternary Content Addressable Memory

Abstract

This paper proposes a novel memory architecture called VP SRAM-based TCAM (Vertically Partitioned Static Random Access Memory based-Ternary Content Addressable Memory) that emulates TCAM functionality with SRAM.VP SRAM-based TCAM dissects conventional TCAM table vertically (column-wise) into TCAM sub-tables, which are then processed to be stored in their corresponding SRAM blocks. During search operation, SRAM blocks are addressed in parallel by their corresponding sub-words of the input word and the read out rows of which are bit-wise ANDed that results in potential matching address(s) where a priority encoder selects the highest priority matching address. Search operation in VP SRAM-based TCAM involves two SRAM accesses followed by ANDing operation. Analysis shows that maximum possible number of vertical partitions reduces size of the proposed TCAM approximately by a factor of 1.3 than its traditional counterpart and offers optimized values for both area and latency of VP SRAM-based TCAM and hence, is a practically feasible alternative to traditional TCAMs.