A Low Power Content Addressable Memory Using Low Swing Search Lines

Abstract

This paper proposes a low power content addressable memory (CAM) using low swing search lines. The CAM reduces the swing voltage and the power consumption of the search lines by using CAM cells as amplifiers. The CAM cells compare the stored data with the low swing search data on the search lines. The CAM also reduces the power consumption of match lines by using low swing NAND-NOR match lines. The 128 × 144 bit CAM chip was fabricated using a 0.18 μm CMOS process with V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DD</sub> = 1.8 V. The CAM chip dissipates 2.82 fj/bit/search and consumes 8.7% of the power used by a conventional dynamic NOR-type CAM. It saves 83.9% and 97.3% of the power in the search lines and the match lines, respectively. Its area is 1.14 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Its maximum operating frequency is 210 MHz.