A 9-T 833-MHz 1.72-fJ/Bit/Search Quasi-Static Ternary Fully Associative Cache Tag With Selective Matchline Evaluation for Wire Speed Applications

Abstract

Hardware search engine (HSE) plays a major role to speed up the search operation in wireless applications. Ternary content addressable memory (TCAM) is such an engine which performs the search in a single clock cycle but the use of separate content and mask storage, various wordlines for read/mask/write, and decoupled data/search lines require substantial design area and consume relatively high power. This article proposes implementation of a state of the art energy-efficient quasi-static ternary fully associative cache tag for wire speed memory access. A 4-T static content and dynamic mask storage have been used with coupled data and search line for reducing the energy dissipation during search. The proposed 128 × 32-bit TCAM tag with selective matchline evaluation scheme has been implemented with predictive 45-nm CMOS process and simulated in SPECTRE at the supply voltage of 1.0 V. The design dissipates an energy of 1.72-fJ/bit/search with a reduction of 32% in the cell area compared to the traditional TCAM.